JP4879347B2 - Relay processing device, relay processing method and program - Google Patents

Description

  The present invention relates to a relay processing apparatus, a relay processing method, and a program, and in particular, when relaying data by encrypted communication, the data can be inspected and the authenticity of a communication partner is confirmed based on a genuine certificate. It is about the technology to do.

  In recent years, as information exchange via the Internet has become active, information security such as damage caused by viruses and malware, loss of social credibility due to customer information in companies, leakage of information such as trade secrets, and monetary loss due to claims for compensation The problem related to is getting worse.

  In general, countermeasures against such problems are taken by firewalls, antivirus software and other software, and information processing devices.

  In particular, in web communications, which accounts for the majority of Internet usage, organizations such as corporations are prohibited from accessing sites that are considered to be used outside of work by systems such as firewalls, URL filtering software, antivirus software, and content filtering software. Measures such as virus inspection / disinfection of downloaded data and access control of externally transmitted data, which is considered to be information leakage, are being implemented.

  These measures are implemented in the user terminal device, and are realized by inspecting the contents of the relayed data in the relay processing system installed in the boundary area between the network in the organization and the Internet. .

  However, with regard to SSL (Secure Socket Layer) / TLS (Transport Layer Security) communication that provides an encryption function for HTTP, which is a Web communication protocol, communication between a client terminal (also simply referred to as a client) and a server. Data to be encrypted is encrypted. In the relay processing system that manages the security as described above, the encrypted data can only be processed by tunneling (through), so the communication contents cannot be inspected, and any application protocol is used for connection. The relay processing system cannot inspect and control what information is being transmitted, what information is being transmitted, and what information is being downloaded.

  For this reason, a network security system (such as a relay processing system) that enhances security as a defensive wall in the boundary area inside and outside the organization is a loophole because it cannot apply detailed inspection of communication contents and access control.

  As a solution to such a problem, communication is performed after the content of encrypted communication is once returned to plain text in the relay processing system by a method called a man-in-the-middle method (man-in-the-middle method). Non-Patent Document 1 describes that data inspection is performed.

  In a normal proxy server, when relaying HTTP communication (HTTPS) over SSL (including TLS), one (for example, between a client and a proxy server) transport layer connection and the other (for example, a proxy server) This is realized by bridging (tunneling) the transport layer connection between the Web server and the Web server. At this time, the SSL connection is established between the client and the Web server.

  On the other hand, in the intermediary method, one SSL connection is established between the client and the proxy server, and another SSL connection is established between the other proxy server and the Web server. Thus, relay processing is realized by bridging application layer data (HTTP transaction data). By adopting such a form, the relay processing system can once decrypt the encrypted relay data (communication data) and perform processing such as inspection on the decrypted plaintext data. It is possible.

  In Patent Document 1, a proxy server creates a temporary encryption communication relay permit that a client receives for server authentication based on a man-in-the-middle system based on a host of a Web server during communication. It is described that it provides.

Eric Rescorla, “Mastering TCP / IP SSL (including TLS)”, Ohmsha 1st edition “9.16.2 man-in-the-middle proxy” JP 2006-165678 A

  However, in Non-Patent Document 1, there is an SSL connection on the client side (SSL connection between the client terminal and the proxy server) and an SSL connection on the Web server side (SSL connection between the proxy server and the Web server). Since they are different from each other, the client terminal cannot acquire the server public key certificate of the Web server, and server authentication provided by SSL (including TLS) may be executed for the Web server. I can't.

  That is, since the client terminal acquires the server public key certificate of the relay processing device provided by the SSL connection with the relay processing device (proxy server) as the certificate of the Web server, It is difficult to confirm the authenticity of the communication partner based on this. This server public key certificate is for the relay processing apparatus, so it is usually fixed to one, and the same certificate is always provided to the client terminal even when the communication destination Web server is different. .

  Similarly, the Web server cannot execute client authentication, which is a function of SSL (including TLS), on the client terminal. The Web server can only acquire the client public key certificate of the relay processing apparatus provided by the SSL connection with the relay processing apparatus as the client certificate. Therefore, it is difficult for the Web server to confirm the authenticity of the client terminal based on the authentic certificate.

  The server authentication function and client authentication function provided by SSL (including TLS) is a mechanism for authenticating whether a communication partner is a correct communication partner, and a malicious third party impersonates a server or client terminal. It is a function to prevent you from being able to perform. For example, as in the above prior art, if server authentication does not work effectively, the user cannot find the impersonation on the server side, and confidential information, personal information, etc. to a malicious server different from the original intention Vulnerabilities such as sending

  Further, in Patent Document 1, a temporary encryption communication relay permit received by a client terminal for server authentication is created by a proxy server based on the host name of the Web server during communication and provided to the client terminal. It is described. However, this encrypted communication relay permit is still different from the true server public key certificate of the Web server that is the original connection destination.

  That is, the client terminal obtains a server public key certificate that is created and presented by the proxy server and is different from the real one as the server public key certificate of the Web server. Therefore, it can be said that the client terminal cannot confirm and verify the true server public key certificate possessed by the Web server, and the function of preventing the Web server spoofing does not work effectively.

  Also, in the above-mentioned Patent Document 1, a method of presenting a client public key certificate included in a proxy server to a Web server is also proposed for client authentication. However, client disclosure of a client terminal stored in the client terminal is proposed. The key certificate cannot be provided to the Web server. For this reason, true client authentication cannot be performed even in the information provision processing device.

  In other words, an SSL connection between the client and the proxy server and an SSL connection between the Web server and the proxy server are established independently, and the client terminal and the WEB server perform encrypted communication via the proxy server. When performing, according to the SSL communication protocol, the public key certificate transmitted and received when establishing each SSL connection is a public key certificate between the apparatuses establishing each SSL connection. Therefore, unless the SSL communication protocol is changed, the client terminal cannot confirm the authenticity of the communication partner (client terminal and Web server) based on the authentic certificate.

  For example, the proxy server adds other data to the data once decrypted for inspection by the proxy server, encrypts the data based on the SSL protocol, and transmits it to the client terminal. It is conceivable that the server public key certificate of the stored WEB server is encrypted based on the SSL protocol and transmitted to the client terminal. In order to realize this, the SSL protocol (SSL protocol) is considered. It cannot be realized without extending.

  This is because the SSL protocol is intended to provide communication data encryption and entity authentication between communication endpoints, and a communication entity other than a communication endpoint (client and Web server) such as a proxy server. Is not defined, and the public key certificate of the client side entity of the SSL connection (public key certificate of the client terminal) and the public key certificate of the server side entity (public key certificate of the Web server) This is because a method for exchanging public key certificates other than () is not defined. Also, in the HTTPS protocol in which data is encapsulated by SSL communication, the proxy server obtains information on the server public key certificate of the Web server acquired by the proxy server when establishing SSL communication between the proxy server and the Web server. This is because the method for transmitting to the client terminal is not defined.

  Therefore, conventionally, when relaying data by encrypted communication without changing each communication protocol of encrypted communication, the data can be inspected and the authenticity of the communication partner is confirmed based on the authentic certificate. Was difficult.

  The present invention has been made in order to solve the above-described problems. The purpose of the present invention is to make it possible to inspect the data when relaying data by encrypted communication, and to communicate with the other party based on a genuine certificate. It is to provide a mechanism for confirming authenticity.

The present invention is a relay processing device that relays communication data communicated between a client terminal and an information processing device, and relays the communication data communicated between the client terminal and the information processing device. Therefore, communication is performed between the client terminal and the information processing apparatus, and first establishment means for establishing first SSL communication used for communication of the communication data between the relay processing apparatus and the client terminal. In order to relay the communication data, second establishment means for establishing second SSL communication used in communication of the communication data between the relay processing device and the information processing device, the relay processing device, and the client terminal Communication establishment means for establishing control communication separately from the first SSL communication, and the information when the second SSL communication is established by the second establishment means The public key certificate of the information processing apparatus is acquired from the management apparatus, using the established control communication by the communication establishing means, and transmitting means for transmitting to said client terminal, control communication established with said communication establishing means The second SSL communication unit establishes a second SSL communication with the acquisition unit that acquires the public key certificate of the client terminal from the client terminal using the client and the public key certificate of the client terminal acquired by the acquisition unit And a public key transmitting means for transmitting to the information processing apparatus as a public key certificate of the relay processing apparatus used when performing the processing .

The present invention is also a relay processing method of a relay processing device for relaying communication data communicated between a client terminal and an information processing device, wherein the first establishing means of the relay processing device includes the client terminal and A first establishment step of establishing a first SSL communication used for communication of the communication data between the relay processing device and the client terminal in order to relay the communication data communicated with the information processing device And the second establishing means of the relay processing device relays the communication data communicated between the client terminal and the information processing device, so that the relay processing device and the information processing device A second establishing step for establishing a second SSL communication used in communication data communication; and a communication establishing means of the relay processing device includes the relay processing device and the client terminal Establishing the control communication separately from the first SSL communication, and when the transmission means of the relay processing device establishes the second SSL communication in the second establishing step, the information processing the public key certificate of the information processing apparatus is acquired from the device, using the control communication established by the communication establishing step, a transmission step of transmitting to said client terminal, acquisition means of the relay processing unit, wherein An acquisition step of acquiring the public key certificate of the client terminal from the client terminal using the control communication established in the communication establishment step, and a public key transmission unit of the relay processing device of the client terminal acquired in the acquisition step The public key certificate is transmitted to the information processing apparatus as the public key certificate of the relay processing apparatus used when establishing the second SSL communication in the second establishing step. Characterized in that it comprises a public key transmission step.

The present invention is also a program that can be read and executed by a relay processing device that relays communication data communicated between a client terminal and an information processing device, and the relay processing device is connected to the client terminal and the information processing device. First establishing means for establishing first SSL communication used for communication of the communication data between the relay processing device and the client terminal in order to relay the communication data communicated with the device; In order to relay the communication data communicated between the client terminal and the information processing device, a second SSL communication used for communication of the communication data between the relay processing device and the information processing device is established. Second establishment means; communication establishment means for establishing control communication between the relay processing device and the client terminal separately from the first SSL communication; The public key certificate of the information processing apparatus acquired from the information processing apparatus when the second establishment means establishes the second SSL communication, using the control communication established by the communication establishment means, Transmission means for transmitting to the client terminal, acquisition means for acquiring the public key certificate of the client terminal from the client terminal using control communication established by the communication establishment means, and disclosure of the client terminal acquired by the acquisition means the key certificate, be made to function as a public key transmission unit that transmits to the information processing apparatus as the public key certificate of the relay processing apparatus for use in establishing the second SSL communication by the second establishing means It is characterized by.

  According to the present invention, when relaying data by encrypted communication, the data can be inspected, and the authenticity of the communication partner can be confirmed based on the authentic certificate.

It is a figure which shows the structure of the relay processing system in embodiment of this invention. It is a figure which shows the hardware constitutions of the various terminals in embodiment of this invention. It is a figure which shows the basic processing flow of the relay processing apparatus in embodiment of this invention. It is a figure which shows the communication system determination processing flow of the user terminal and relay processing apparatus in embodiment of this invention. It is a figure which shows the server certificate verification processing flow of the user terminal and relay processing apparatus in embodiment of this invention. It is a figure which shows the client authentication processing flow of the user terminal and relay processing apparatus in embodiment of this invention. It is a figure which shows the AP data relay processing flow of the relay processing apparatus in embodiment of this invention. It is a figure which shows the example of the communication system determination table of the relay processing apparatus in embodiment of this invention. It is a figure which shows the example of the proxy communication system cache table of the relay processing apparatus in embodiment of this invention. It is a figure which shows the example of the proxy communication session management table | surface of the relay processing apparatus in embodiment of this invention. It is a figure which shows the example of a communication processing flow at the time of newly producing the SSL session of the relay processing system in embodiment of this invention. It is a figure which shows the example of a communication processing flow at the time of reusing the SSL session of the relay processing system in embodiment of this invention. It is a figure which shows the example of the communication system selection dialog box in embodiment of this invention. It is a figure which shows the example of the communication system selection dialog box in embodiment of this invention. It is a figure which shows the server public key certificate confirmation dialog box in embodiment of this invention. It is a figure which shows the example of the client communication system cache table of the user terminal in embodiment of this invention. It is a figure which shows the example of the server certificate cache table | surface of the user terminal in embodiment of this invention. It is a figure which shows the example of the display screen of the browsing process part of the user terminal in embodiment of this invention. It is a functional block diagram of the relay processing device in the present invention. It is a functional block diagram of the relay processing device in the present invention.

  Hereinafter, the present invention will be described in detail according to preferred embodiments with reference to the accompanying drawings.

<First Embodiment>
(System configuration and management table)
FIG. 1 is a diagram showing a configuration of a relay processing system in an embodiment of the present invention.

  Note that the configurations of various terminals and various devices connected to the network in FIG. 1 are merely examples, and it goes without saying that there are various configuration examples depending on applications and purposes.

  The relay processing system includes a user terminal 110, a relay processing device 120, and an information provision processing device 150. The user terminal 110 and the relay processing device 120, and the relay processing device 120 and the information provision processing device 150 are connected to each other via a network so that they can communicate with each other.

  The user terminal 110 is an application example of the client terminal of the present invention. The relay processing device 120 is an application example of the relay processing device of the present invention. The information provision processing device 150 is an application example of the information processing device of the present invention.

  The user terminal 110 is an information processing apparatus used for acquiring and displaying content data provided by the information provision processing apparatus 150. The user terminal 110 includes a browsing processing unit 111, an extended function processing unit 112, an encryption key storage unit 113, a management table storage unit 114, and a CA certificate storage unit 115.

  The browsing processing unit 111 is a function processing unit that corresponds to a client program of an HTTP protocol or HTTPS protocol generally called a Web browser. The browsing processing unit 111 receives an instruction from the user, transmits a communication request message to the information provision processing device 150 via the relay processing device 120, and receives a response from the information provision processing device 150 to the communication request message. The communication response message is received, and the communication response message is shaped and displayed on the CRT 210 of the user terminal 110. At this time, a communication connection established between the browsing processing unit 111 and the client communication unit 121 of the relay processing device 120 is a proxy line 161.

  Here, the proxy line 161 (first SSL communication) is SSL-encrypted communication established between the user terminal 110 and the relay processing device 120, and does not indicate a physical line. Rather, virtual (logical) communication for performing encrypted communication is shown. The proxy line 161 (first SSL communication) is different from control communication (control line 162) described later.

  The encryption key storage unit 113 is a storage area for storing a secret key corresponding to the public key certificate of the user terminal.

  The browsing processing unit 111 is an encryption key storage unit when performing HTTPS communication with the information provision processing device 150 and when SSL (including TLS) client authentication is requested from the information provision processing device 150. 113 has a function of responding to a client authentication request using the public key certificate and the private key stored in 113.

  The extended function processing unit 112 is connected to the browsing processing unit 111 and has a function of executing an interrupt process for the communication processing of the browsing processing unit 111. Further, the extended function processing unit 112 can communicate with the control processing communication unit 128 of the relay processing device 120. When an HTTPS communication request event occurs, the extended function processing unit 112 inquires about the communication method of the HTTPS communication to the relay processing device. A function of presenting result information to the user and requesting confirmation or selection, and a function of transmitting information on the result of confirmation or selection to the relay processing device are provided. Further, the extended function processing unit 112 acquires a server public key certificate possessed by the information providing processing device 150 that is a communication destination during HTTPS communication from the control processing communication unit 128, and a function to verify the server public key certificate It has. Further, the extended function processing unit 112 controls the client public key certificate information stored in the encryption key storage unit 113 when the information providing processing device 150 that is the communication destination requests client authentication during HTTPS communication. The function to be transmitted to the communication unit 128 and the control processing communication unit 128 receive signature target data (message digest) and sign the signature target data with the client private key stored in the encryption key storage unit 113 And a function of transmitting the signature data to the control processing communication unit 128. A communication connection established (established) between the extended function processing unit 112 and the control processing communication unit 128 of the relay processing device 120 is defined as a control line 162.

  The control line 162 is established (established) as an encrypted communication line by SSL between the user terminal 110 and the relay processing device 120. Thereby, the user terminal 110 can prevent spoofing of the relay processing device 120.

  That is, the relay processing device 120 establishes control communication (control line 162) with the user terminal 110 (communication establishment means). Here, the control communication (control line 162) is a connection for encrypted communication by SSL established between the user terminal 110 and the relay processing device 120, and does not indicate a physical line. 2 shows a virtual (logical) communication path for performing encrypted communication.

  The relay processing device 120 establishes control communication (control line 162) according to a general SSL communication establishment procedure.

  The management table storage unit 114 is a storage area for storing a client communication method cache table and a server certificate cache table.

(Explanation of client communication method cache table)

  The client communication system cache table is a storage area having a data structure as shown in FIG. Each row record is for holding the communication method when the browsing processing unit 111 of the user terminal 110 determines the communication method with the specific information provision processing device 150. The record has a server identifier column, a determination date column, and a communication method column.

  The server identifier column is a place for storing a combination of the host name and TCP port number of the information provision processing device 150 for identifying the information provision processing device 150 as a communication destination. The determined date / time column is a place where the date / time information on which the communication method is determined is stored. The communication method column is a place where the determined communication method is stored.

  There are two types of values stored in the communication method column: “direct” and “proxy”. “Direct” is a value that means that the relay processing apparatus 120 performs a tunneling process so as to be performed in a normal proxy server without terminating an SSL connection of HTTPS communication. The “proxy” is a value that means that the relay processing device 120 performs processing in the middleman method that terminates the SSL connection of HTTPS communication.

  For each record held in the client communication method cache table (FIG. 16), the cache is cleared (deleted) based on the information of the determination date. For example, when each record is periodically inspected by the user terminal 110 and the value in the determination date / time column is compared with the inspection date / time, the date / time indicates a date that is older than an appropriately determined effective time (for example, 6 hours). Deleted. Also, when the browser process corresponding to the browsing processing unit 111 of the user terminal 110 is completed, all records in the table (FIG. 16) are deleted.

  When the user terminal 110 receives an access request to the information provision processing device 150, the user terminal 110 refers to the client communication method cache table, and if the information regarding the communication method with the information provision processing device 150 can be reused, Communication can be started without performing a process for allowing the user to check or select the communication method each time.

(Explanation of server certificate cache table)

  The server certificate cache table is a storage area having a data structure as shown in FIG. Each row record holds an SSL session ID (also simply referred to as a session ID) and a server public key certificate used when communicating with a specific information provision processing device 150 that the user terminal 110 has accessed in a proxy manner. Is for. The record has a server identifier field, a last use date / time field, a session ID field, and a server certificate field.

  The server identifier column is information for identifying the information providing processing device 150 that has communicated, and is a place where a combination of the host name and TCP port number of the information providing processing device 150 is stored. The last use date and time column is a place where the date and time information on which the communication process represented by the record is performed is stored. The session ID column is a place where the value of the SSL session ID notified from the relay processing device 120 in the communication is stored. The server certificate column is a place where the server public key certificate of the information provision processing device 150 acquired from the relay processing device 120 by the communication is stored.

  Each record held in the server certificate cache table is periodically inspected, and SSL session cache information managed by the browsing processing unit 111, which is usually software such as a browser (for the browser to resume SSL session) If the same session ID does not exist in the SSL session cache information, the record is deleted.

  When the user terminal 110 accesses the information provision processing device 150 in a proxy manner via the relay processing device 120, the session resumption function is used in the SSL session between the user terminal 110 and the relay processing device 120. When the user terminal 110 refers to the server certificate cache table, the contents for confirming the server public key certificate of the information provision processing device 150 by the user operating the user terminal 110 In response to a display request, display processing can be performed using the value in the server certificate column of the server certificate cache table without accessing the relay processing device 120 each time. That is, the user terminal 110 can display the value in the server certificate column of the server certificate cache table without accessing the relay processing device 120.

  The CA certificate storage unit 115 is a storage area for storing a CA certificate trusted by the user terminal 110 used when verifying the server public key certificate of the information provision processing device 150.

  The relay processing device 120 is an information processing device having a function of a program or device generally called a proxy server. The relay processing device 120 receives the communication request message transmitted from the user terminal 110, relays the communication request message to the information providing processing device 150 that is the destination, and responds to the communication response from the information providing processing device 150. The message can be relayed to the user terminal 110.

  The relay processing device 120 includes a client communication unit 121, a server communication unit 122, a client side encryption processing unit 123, a communication control unit 124, a server side encryption processing unit 125, a proxy encryption key storage unit 126, and a server. The encryption key storage unit 127 includes a control processing communication unit 128, a management table storage unit 129, an additional function processing unit 130, and a CA certificate storage unit 131.

  The client communication unit 121 has a function of accepting a connection request from the browsing processing unit 111 of the user terminal 110, receiving a communication request message, and transmitting a communication response message to the browsing processing unit 111.

  The server communication unit 122 has a function of connecting to the server processing unit 151 of the information provision processing device 150, transmitting a communication request message, and receiving a communication response message from the server processing unit 151.

  The client-side cryptographic processing unit 123 establishes SSL (including TLS) in the communication line (proxy line 161) with the browsing processing unit 111 of the user terminal 110 when the communication method in the relay processing device 120 is the proxy method. A function for performing server-side processing is provided.

  The communication control unit 124 includes a process performed by the client communication unit 121, a process performed by the client side cryptographic processing unit 123, a process performed by the additional function processing unit 130, a process performed by the server communication unit 122, and a server side cryptographic processing unit. It has a function of performing synchronous control processing between the processing performed by 125 and the processing performed by the control processing communication unit 128. In addition, the communication control unit 124 has a function of storing information related to the synchronization control process in the management table storage unit 129 and a function of referring to the management table storage unit 129.

  When the communication method in the relay processing device 120 is a proxy method, the server-side encryption processing unit 125 performs an SSL (including TLS) connection in a communication line (server line 163) with the server processing unit 151 of the information providing processing device 150. A function for performing client side processing is provided.

  Here, the server line 163 (second SSL communication) is SSL encrypted communication established between the relay processing device 120 and the information providing processing device 150, and indicates a physical line. Instead, it is a virtual (logical) communication that performs encrypted communication.

  In the example of FIG. 1, the user terminal 110 and the relay processing device 120 are connected via a single physical communication line so that they can communicate with each other. In the example of FIG. 1, the relay processing device 120 and the information provision processing device 150 are connected to be communicable with each other.

  The proxy encryption key storage unit 126 includes a server public key certificate used in the SSL (including TLS) handshake process on the proxy line 161 when the communication method in the relay processing device 120 is the proxy method. This is a storage area that stores a secret key.

  The control processing communication unit 128 is a function processing unit having a function as an HTTPS server, and establishes a secure communication connection (the control line 162) with the extended function processing unit 112 of the user terminal 110, so that the user A function of receiving a communication request message transmitted by the extended function processing unit 112 of the terminal 110, a function of transmitting a communication response message to the extended function processing unit 112 of the user terminal 110, and an extended function processing unit 112 of the user terminal 110 A function to answer the communication method based on the information in the communication method determination table of the management table storage unit 129 and the extended function processing unit 112 of the user terminal 110 The communication method determination information related to the communication destination of the management table is received, and the determination information is stored in the proxy communication method cache table of the management table storage unit 129. A function, a function of transmitting the server public key certificate of the information provision processing device 150 to the extended function processing unit 112 of the user terminal 110, and a verification result of the server public key certificate from the extended function processing unit 112 of the user terminal 110 , A function for notifying the communication control unit 124 of the verification result, a function for transmitting client authentication request information to the extended function processing unit 112 of the user terminal 110, and an extended function processing unit 112 of the user terminal 110. A function for receiving a client public key certificate from the communication controller 124, a function for receiving signature target data from the communication control unit 124, a function for transmitting the signature target data to the extended function processing unit 112 of the user terminal 110, and a user terminal 110, a function for receiving signature data from the extended function processing unit 112, and a function for notifying the communication control unit 124 of the signature data.

  The server encryption key storage unit 127 is a storage area that stores a server public key certificate and a private key used in the SSL (including TLS) handshake process on the control line 162.

  The management table storage unit 129 is a storage area for storing a communication method determination table, a proxy communication method cache table, and a proxy communication session management table.

(Explanation of communication method determination table)

  The communication method determination table (FIG. 8) is a table used to determine how to relay the HTTPS communication (communication method) prior to the HTTPS communication through the proxy line 161. The record of the communication method determination table is composed of server conditions, client conditions, and communication methods. An example of the communication method determination table is shown in FIG. The communication method determination table (FIG. 8) is an application example of communication method setting information.

Server conditions consist of a domain name field and a category field. The domain name column is a place for storing the character string condition of the host name of the information provision processing device 150 in communication. “*” Represents a wild card character string and matches an arbitrary character string. The category column is a place where the category of the information provision processing device 150 in communication is stored. A category is a field to which an arbitrary information provision processing device 150 belongs according to the content provided by the information provision processing device 150. The relay processing device 120 determines the category of the URL according to the URL (including the host name) included in the encrypted communication request event transmitted from the user terminal 110. As an example, the relay processing apparatus 120 is provided with a correspondence table indicating the correspondence between host names and categories in advance, and the category corresponding to the host name of the URL input from the user terminal 110 is determined with reference to the correspondence table. (Determining) can be considered.
Here, the server condition is an application example of relay destination information indicating the information provision processing device 150 of the relay destination of data transmitted from the user terminal 110.

  The client condition is composed of an address field and an authentication group field. The address column is a place for storing the IP address condition of the user terminal in communication. In addition to individual designation of IP addresses, a plurality of addresses can be represented by a wild card character string or network address expression. The authentication group column is a place where the group name to which the user of the user terminal 110 belongs is stored.

  The communication method column is a place for storing a communication method permitted to be established. That is, in the communication method column, a communication method (communication method information) permitted to be established is set in order to enable data relay.

  There are three types of values stored in the communication method column: “direct” (direct communication method), “proxy” (proxy communication method), and “select”. “Direct” is a value for instructing the tunnel processing to be performed in the normal proxy server without terminating the SSL (including TLS) connection of the HTTPS communication in the relay processing device 120. The “proxy” is a value indicating a middleman method for terminating the SSL communication SSL connection in the relay processing device 120. “Selection” (selection information) is a value for instructing the user of the user terminal 110 to select the direct method or the proxy method.

(Description of proxy communication method cache table)

  The proxy communication method cache table (FIG. 9) is a table used for storing a communication method applied to a specific HTTPS communication. The record of the proxy communication method cache table includes a client identifier field, a server identifier field, an expiration date field, and a communication method field. An example of the proxy communication method cache table is shown in FIG.

  The client identifier column includes the IP address of the user terminal 110 and the identifier of the browsing processing unit 111 (viewing processing) as information for identifying the browsing processing unit 111 of the user terminal 110 (client specifying information for specifying the user terminal). This is a place for storing information combining the (part identifier). For example, a process ID is assumed to be used as the browsing processing unit identifier. The server identifier column is a place where information combining the host name of the information provision processing device 150 and the TCP port number is stored as information for identifying the information provision processing device 150. The expiration date column is a place where the expiration date information of the target record is stored. The communication method column is a place where the determined communication method is stored.

  Each record held in the proxy communication method cache table is periodically inspected by the relay processing device 120, and is deleted when the date and time in the expiration date column is older than the inspection date and time.

(Explanation of proxy communication session management table)

  The proxy communication session management table (FIG. 10) is a table used for storing session information related to communication relayed by the proxy method. The records of the proxy communication session management table include a client identifier field, a server identifier field, a last use date / time field, client-side handshake information (session ID-C field, common key and others-C field, client certificate field), server-side hand It is composed of shake information (session ID—S field, common key and others—S field, server certificate field, client authentication request field). An example of the proxy communication session management table is shown in FIG.

  The client identifier column is a place where information combining the IP address of the user terminal 110 and the identifier of the browsing processing unit 111 (viewing processing unit identifier) is stored as information for identifying the browsing processing unit 111 of the user terminal 110. is there. The server identifier column is a place where information obtained by combining the host name of the information provision processing device 150 and the TCP port number is stored as information for identifying the information provision processing device 150. The last use date / time column is a place for storing date / time information on the communication represented by the target record. The session ID-C column is a place where the ID of the SSL session on the proxy line 161 is stored. The common key and other-C column is a place for storing information on the common key and cipher suite exchanged in the handshake processing of the SSL session on the proxy line 161. The client certificate column is a place where the client public key certificate acquired from the user terminal 110 is stored. The session ID-S column is a place where the ID of the SSL session on the server line 163 is stored. The common key and other-S column is a place for storing information regarding the common key and cipher suite exchanged in the handshake processing of the SSL session on the server line 163. The server certificate column is a place where the server public key certificate of the information provision processing device 150 acquired by the handshake processing of the SSL session on the server line 163 is stored. The client authentication request field is a place where the client authentication request information from the information provision processing device 150 acquired by the handshake processing of the SSL session on the server line 163 is stored.

  Each record held in the proxy communication session management table is periodically inspected by the relay processing device 120, the value in the last use date and time column is compared with the inspection date and time, and an appropriately determined valid time (for example, 12). If the date is older than (time), it is deleted.

  The additional function processing unit 130 receives the communication request message received from the user terminal 110 and the information providing processing device 150 when the communication to be relayed is HTTP and when the relay method is the proxy method even in the case of HTTPS. A function of performing additional function processing on the communication response message is provided. The additional function processing corresponds to, for example, a cache function generally implemented in a proxy server, a content filtering function implemented in a security gateway or the like, a virus inspection / disinfection function, an access control function, and the like. These functions are usually not applicable (implemented) when the communication message is encrypted as in HTTPS communication, but in the relay processing apparatus even in HTTPS communication as in the proxy method shown in the present embodiment. It can be applied (implemented) by using a method for plainly encrypting communication messages.

  The CA certificate storage unit 131 is a storage area for storing a CA certificate trusted by the relay processing device 120 and used when verifying the server public key certificate of the information providing processing device 150.

  The information provision processing device 150 is an information processing device that receives a communication request message sent from the user terminal 110 and responds with a communication response message based on the content of the communication request message. The information provision processing device 150 includes a server processing unit 151 and a server encryption key storage unit 152.

  The server processing unit 151 is a function processing unit corresponding to a program generally known as a Web server. The server processing unit 151 has server functions of HTTP protocol and HTTPS protocol.

  The server encryption key storage unit 152 is a storage area for storing a server public key certificate and a private key used when the server processing unit 151 performs encrypted communication using HTTPS.

  Next, the hardware configuration of various terminals of the user terminal 110, the relay processing device 120, and the information provision processing device 150 in FIG. 1 will be described with reference to FIG. The user terminal 110, the relay processing device 120, and the information provision processing device 150 are generally known information processing devices.

  FIG. 2 is a diagram illustrating a hardware configuration of various terminals according to the embodiment of the present invention.

  The CPU 201 comprehensively controls each device and controller connected to the system bus 204.

  Further, the ROM 202 or the external memory 211 is necessary to realize a BIOS (Basic Input / Output System) or an operating system program (hereinafter referred to as an OS), which is a control program of the CPU 201, or a function executed by each server or each PC. Various programs to be described later are stored. The RAM 203 functions as a main memory, work area, and the like for the CPU 201.

  The CPU 201 implements various operations by loading a program necessary for execution of processing into the RAM 203 and executing the program.

  An input controller (input C) 205 controls input from a pointing device such as a keyboard 209 or a mouse (not shown).

  A video controller (VC) 206 controls display on a display device such as a CRT display (CRT) 210. The display device may be a liquid crystal display as well as a CRT. These are used by the administrator as needed. The present invention is not directly related.

  A memory controller (MC) 207 is a hard disk (HD), floppy disk (registered trademark FD) or PCMCIA card slot for storing boot programs, browser software, various applications, font data, user files, editing files, various data, and the like. Controls access to an external memory 211 such as a compact flash memory connected via an adapter.

  A communication I / F controller (communication I / FC) 208 is connected to and communicates with an external device via a network, and executes communication control processing in the network. For example, Internet communication using TCP / IP is possible.

  Note that the CPU 201 enables display on the CRT 210 by executing outline font rasterization processing on a display information area in the RAM 203, for example. In addition, the CPU 201 enables a user instruction with a mouse cursor (not shown) on the CRT 210.

  A program for realizing the present invention is recorded in the external memory 211, and is executed by the CPU 201 by being loaded into the RAM 203 as necessary. Further, the above-described encryption key storage unit 113, management table storage unit 114, CA certificate storage unit 115, proxy encryption key storage unit 126, server encryption key storage unit 127, management table storage unit 129 used by the program according to the present invention. The CA certificate storage unit 131 and the server encryption key storage unit 152 are stored in the external memory 211.

(Communication message exchange flow when relaying encrypted communication by proxy method)

  Next, one case of a communication message exchange flow among the user terminal 110, the relay processing device 120, and the information providing processing device 150 when data communicated via encrypted communication is relayed by a proxy method Will be described with reference to FIG.

  FIG. 11 is a communication message between the user terminal 110, the relay processing device 120, and the information providing processing device 150 when data communicated via encrypted communication in the embodiment of the present invention is relayed by a proxy method. It is a figure which shows the example of no exchange flow.

  Note that the communication surrounded by the broken lines shown in steps S1150 to S1154 in FIG. 11 is performed via the control line 162. Other communication between the user terminal 110 and the relay processing device 120 is performed via the proxy line 161.

  Communication between the relay processing device 120 and the information provision processing device 150 is performed via the server line 163.

  In FIG. 11 and FIG. 12, a message (such as ChangeCipherSpec) required in the SSL (including TLS) standard is a generally known process based on a general SSL (including TLS) standard. Therefore, the description is omitted here.

  In step S1101, in the user terminal 110, on the browser screen provided by the browsing processing unit 111, the user inputs a URL indicating the content on the information provision processing device 150 into an address bar or the like, or has already been displayed on the browser screen. A content acquisition request is instructed by clicking on a link character string to the URL in the content.

  In step S1102, the extended function processing unit 112 is activated by an event handler registered in the browsing processing unit 111 in response to the content acquisition request. The extended function processing unit 112 acquires the schema portion of the URL included in the content acquisition request, and determines whether the schema is HTTPS (encrypted communication). That is, the user terminal 110 determines whether or not it has requested transmission / reception of data by encrypted communication included in the content acquisition request.

  When the user terminal 110 determines that the schema is HTTPS (a request for data transmission / reception via encrypted communication), the user terminal 110 performs relay processing to determine the communication method in the relay processing device 120. A communication method inquiry is made to the device 120. That is, the user terminal 110 transmits a communication method inquiry request message described later to the relay processing device 120.

  In step S1103, the relay processing device 120 identifies the identifier (server identifier) of the information provision processing device 150 and the browsing processing unit identifier of the user terminal 110 included in the inquiry (communication method inquiry request message) transmitted from the user terminal 110. Based on the information (client identifier), the communication method is determined from the communication method determination table (FIG. 8) of the management table storage unit 129, and the communication method is returned to the user terminal 110. In this example, “select” is responded.

  That is, when the communication method is determined to be “selected”, the relay processing device 120 displays, for example, screen information for displaying a dialog box (also referred to as a communication method selection dialog box) shown in FIG. Transmit to terminal 110.

  In step S1104, since the communication method received in step S1103 is “select”, the user terminal 110 displays a screen (also referred to as a selection dialog box) as shown in FIG.

  That is, the screen of FIG. 14 is displayed according to the screen information transmitted in step S1103.

  In step S1105, at the user terminal 110, the user uses the selection dialog box to select a communication method from “direct” or “proxy”. In the example, the user selects “permit” and the communication method “proxy” is selected.

  That is, in step S1105, if the user presses the “permit” button or the “not permit” button via the selection dialog box, and the “permit” button is pressed, the communication method is “proxy”. When the “Do not allow” button is pressed, the communication method is determined as “Direct”. In this example, the “allow” button is selected by the user, and the communication method is determined to be “proxy”.

  In step S1106, the user terminal 110 notifies the communication method of the selection result (also referred to as a communication method notification message) (in this example, “proxy” as the selection method, the server identifier, the client identifier, and the expiration date). Included in the message) to the relay processing device 120.

  The relay processing device 120 receives the selection result, and stores the selection result (“proxy”) in the proxy communication method cache table (FIG. 9) of the management table storage unit 129.

  In step S <b> 1107, the user terminal 110 determines that the communication method regarding the content acquisition request has been determined and has completed the notification (transmission) of the communication method notification message to the relay processing device 120. Resumes acquisition request processing. The browsing processing unit 111 connects to the client communication unit 121 of the relay processing device 120 to open the proxy line 161 and transmits a proxy request by the CONNECT method on the proxy line 161. A proxy request by the CONNECT method is a request issued when a client such as a Web browser connects to an HTTPS server via a proxy server, and has the following format.

  CONNECT host name: port number HTTP / 1.0

Further, the extended function processing unit 112 instructs the browsing processing unit 111 to add a client identifier as a header to the proxy request.
An example of a proxy request is shown.

CONNECT www. xxx. co. jp: 443 HTTP / 1.0
User-Agent: XXXX / X. X
X-client-id: 10.10.10.1:349263

  Next, the relay processing device 120 acquires a server identifier (host name: port number) and a client identifier (X &#8722; client &#8722; id) from the received proxy request, and stores them in the management table using these as keys. The value “proxy” is acquired by referring to the communication method column from the proxy communication method cache table of the part 129. Then, the relay processing device 120 creates a new record (referred to as a proxy communication session record) in the proxy communication session management table of the management table storage unit 129 as a storage area for managing information of the proxy method relay processing.

  In step S1108, the relay processing device 120 establishes a TCP connection to the information providing processing device 150 based on the server identifier information, and opens the server line 163.

  In step S <b> 1109, the relay processing device 120 receives the fact that the TCP connection is successful, returns a connection success message “HTTP / 1.0 200” to the user terminal 110, and can relay to the information provision processing device 150. Tell.

  In step S1110, the user terminal 110 transmits a Client Hello message on the proxy line 161 and starts an SSL handshake.

  Upon receiving the Client Hello message, the relay processing device 120 starts the SSL handshake process, and performs the process of establishing the proxy line 161 until the handshake process ends in step S1133.

  In order to establish an SSL encrypted communication line, handshake processing is started from step S1110. When the handshake process is completed in step S1133, a proxy line 161 (SSL encrypted communication line) can be established. The proxy line 161 is an application example of the first SSL communication of the present invention.

  In step S <b> 1111, the relay processing device 120 transmits the Client Hello message generated by the server-side cryptographic processing unit 125 in order to open (establish) an SSL session with the information providing processing device 150 on the server line 163. Send.

  Upon receiving the Client Hello message, the information provision processing device 150 starts the SSL handshake process, and performs the process of establishing the server line 163 until the handshake process ends in step S1131.

  In order to establish an SSL encrypted communication line, handshake processing is started from step S1111. When the handshake process is completed in step S1131, the server line 163 (SSL encrypted communication line) can be established. The server line 163 is an application example of the second SSL communication of the present invention.

  In step S1111, the relay processing device transmits an SSL Client Hello message on the server line 163, and starts an SSL handshake.

  In order to establish a line for encrypted communication by SSL, handshake processing is started in step S1110. When the handshake process is completed in step S1133, a proxy line 161 (SSL encrypted communication line) can be established. The proxy line 161 is an application example of the first SSL communication of the present invention.

The processing after step S1110 will be described below.
FIG. 11 illustrates a case where the communication method is “proxy” (proxy method).
First, the user terminal 110 transmits an SSL handshake start request (SSL Client Hello) in step S1110.

  Since FIG. 11 is a sequence diagram when the communication method is “proxy”, the relay processing device 120 does not directly relay each message received by the SSL handshake to the information providing processing device 150. Handshake as a server.

  The relay processing device 120 transmits each message of SSL Server Hello, SSL Server Certificate, and SSL Server Hello Done to the user terminal 110 in order to respond to handshake processing as a server itself.

  First, the browsing processing unit 111 of the user terminal 110 determines whether SSL session information (including a session ID) used in communication with the relay processing apparatus 120 in the past is stored.

  If the browsing processing unit 111 of the user terminal 110 determines that an SSL session ID used in communication with the relay processing device 120 has been stored in the past, the SSL Client Hello including the session ID is stored. The message is transmitted to the relay processing device 120.

On the other hand, if the browsing processing unit 111 of the user terminal 110 determines that the SSL session ID used in communication with the relay processing apparatus 120 has not been stored in the past, the browsing client 111 does not include the session ID. A Hello message is transmitted to the relay processing device 120.
Then, the relay processing device 120 receives the SSL Client Hello message from the user terminal 110.

  FIG. 11 illustrates a case where the session ID is not included in the SSL Client Hello message received from the user terminal 111 (a case where a new SSL session is used without resuming the SSL session).

  The case where the session ID is included in the SSL Client Hello message received from the user terminal 111 (when the SSL session is resumed) will be described later with reference to FIG.

  When the relay processing apparatus 120 receives the SSL Client Hello message from the user terminal 110 in step S1110, the relay processing apparatus 120 determines whether or not the session ID is included in the SSL Client Hello message. Then, when it is determined that the session ID is not included in the SSL Client Hello message, the relay processing device 120 generates a new unique session ID to create a new session.

  Then, the relay processing device 120 transmits an SSL Server Hello message including the generated session ID to the user terminal 110 (step S1112).

  Further, the relay processing device 120 stores the generated session ID in the session ID-C column of the proxy communication session management table (FIG. 10). The session ID becomes an identifier when the session is resumed after the next time.

  Upon receiving the SSL Server Hello message including the session ID from the relay processing device 120, the user terminal 110 stores the session ID included in the SSL Server Hello message in a memory such as the RAM 203 as SSL session information (cache). To do).

  Next, the relay processing device 120 transmits an SSL Server Certificate message including the server public key certificate stored in the proxy encryption key storage unit to the user terminal 110 (step S1113).

  The user terminal 110 receives the SSL Server Certificate message from the relay processing device 120 and stores it in a memory such as the external memory 211.

  Then, the relay processing device 120 transmits an SSL Server Hello Done message notifying the end of a series of processing in the relay processing device 120 to the user terminal 110 (step S1114).

  Upon receiving the SSL Server Hello Done message from the relay processing device 120, the user terminal 110 generates a master secret (information for generating a common key used for data encryption and decryption).

  Further, the user terminal 110 generates a common key used to encrypt and decrypt data to be communicated with the relay processing device 120 via the proxy line 161 according to the master secret generated here. The generated common key is stored in a memory such as the RAM 203.

  When the user terminal 110 transmits data to the relay processing device 120 via the proxy line 161 in the processes after step S1134, the user terminal 110 encrypts the data using the common key generated here and transmits the data. .

  Also, the user terminal 110 decrypts the encrypted data transmitted from the relay processing device 120 via the proxy line 161 using the common key generated here.

  Then, the user terminal 110 encrypts the generated master secret using the server public key included in the server public key certificate included in the SSL Server Certificate message received from the relay processing device 120. .

Then, the user terminal 110 transmits a Client Key Exchange message including the encrypted master secret to the relay processing device 120.
The relay processing device 120 receives the Client Key Exchange message from the user terminal 110.

  Then, the relay processing device sends the server public key certificate (including the server public key) included in the SSL Server Certificate message transmitted to the user terminal 110 to the encrypted master secret included in the Client Key Exchange message. The private key corresponding to is decrypted.

  The secret key used here is stored in the proxy encryption key storage unit 126 in association with the server public key certificate (including the server public key), and is transmitted to the user terminal 110. It corresponds to the certificate (including the public key of the server).

  Next, the relay processing device 120 generates a common key according to the decrypted master secret. Then, the relay processing device 120 stores the generated common key information in the common key and other-C column of the proxy communication session record.

  When the relay processing device 120 transmits the data to the user terminal 110 via the proxy line 161 in the processing after step S1134, the relay processing device 120 encrypts and transmits the data using the generated common key. . Further, the relay processing device 120 decrypts the encrypted data transmitted from the user terminal 110 via the proxy line 161 using the common key generated here.

  Next, processing after step S1115 will be described.

  When the relay processing device 120 receives the SSL Client Hello message from the user terminal 110, the relay processing device 120 transmits an SSL handshake start request (SSL Client Hello message) to the information providing processing device 150 using the relay processing device 120 as a client (step S1). S1111).

In response to the SSL Client Hello message received from the relay processing device 120, the information provision processing device 150 sends an SSL Server Hello message (step S1115), an SSL Server Certificate message (step S1116), and an SSL certificate request to the relay processing device 120. A message (step S1117) and an SSL Server Hello Done message (step S1118) are transmitted.
Hereinafter, steps S1115 to S1118 will be described.

  First, the relay processing device 120 determines whether or not SSL session information (session ID) used in communication with the information providing processing device 150 in the past is stored.

  Specifically, in the past, when the user terminal 110 and the information provision processing device 150 communicate with each other via the relay processing device 120 in a proxy manner, the relay processing device 120 and the information provision processing device 150 The relay processing device 120 determines whether or not the session ID used on the server line 163 is stored in the session ID-S column of the proxy communication session management table (FIG. 10).

  In the past, the relay processing device 120, when the user terminal 110 and the information provision processing device 150 communicate with each other via the relay processing device 120 in a proxy manner, If it is determined that the session ID used on the server line 163 between the two is stored in the session ID-S field of the proxy communication session management table (FIG. 10), the SSL Client Hello including the session ID is stored. The message is transmitted to the information provision processing device 150.

  On the other hand, when the relay processing apparatus 120 communicates with the user terminal 110 and the information provision processing apparatus 150 via the relay processing apparatus 120 in the past in a proxy manner, the relay processing apparatus 120 and the information provision processing apparatus 150 If it is determined that the session ID used on the server line 163 between the two is not stored in the session ID-S field of the proxy communication session management table (FIG. 10), the SSL Client is not included. A Hello message is transmitted to the information provision processing device 150 (S1111).

  Then, the information provision processing device 150 receives the SSL Client Hello message from the relay processing device 120.

  FIG. 11 illustrates a case where the session ID is not included in the SSL Client Hello message received from the relay processing device 120 (when a new SSL session is used without resuming the SSL session).

  A case where the session ID is included in the SSL Client Hello message received from the relay processing device 120 (when the SSL session is resumed) will be described later with reference to FIG.

  When receiving the SSL Client Hello message from the relay processing device 120 in step S1111, the information providing processing device 150 determines whether or not the session ID is included in the SSL Client Hello message.

  When it is determined that the session ID is not included in the SSL Client Hello message, the information provision processing device 150 generates a new unique session ID to create a new session.

  Then, the information provision processing device 150 transmits an SSL Server Hello message including the generated session ID to the relay processing device 120 (step S1115).

  Further, the information provision processing device 150 stores (caches) the generated session ID as SSL session information in a memory such as the RAM 203.

  When the relay processing device 120 receives the SSL Server Hello message including the session ID from the information providing processing device 150, the relay processing device 120 converts the session ID included in the SSL Server Hello message into the session ID of the proxy communication session management table (FIG. 10). -Store in column S. The session ID becomes an identifier when the session is resumed after the next time.

  Next, the information provision processing device 150 transmits an SSL Server Certificate message including the server public key certificate of the information provision processing device 150 stored in the server encryption key storage unit 152 to the relay processing device 120.

  In step S1116, the relay processing device 120 receives the SSL Server Certificate message from the information provision processing device 150, and acquires the server public key certificate of the information provision processing device 150 included in the message.

  The relay processing device 120 performs verification processing of whether or not the server public key certificate can be trusted using a CA public key certificate stored in the CA certificate storage unit 131. In this example, the verification is successful, and the server public key certificate is stored in the server certificate column of the proxy communication session record.

  In step S1117, the relay processing device 120 receives an SSL Certificate Request message (client authentication request information) from the information providing processing device 150, and information on request conditions (signature algorithm, CA identification name) related to client authentication included in the message. Is stored in the client authentication request field of the proxy communication session record.

  Then, the information provision processing device 150 transmits an SSL Server Hello Done message notifying the end of a series of processes in the information provision processing device 150 to the relay processing device 120.

  In step S <b> 1118, the relay processing device 120 receives an SSL Server Hello Done message from the information providing processing device 150.

  In step S 1119, the user terminal 110 transmits a server public key certificate acquisition request message of the information provision processing device 150 to the relay processing device 120 using the control line 162.

  In step S1120, in response to the acquisition request message transmitted from the user terminal 110, the relay processing device 120 obtains the server public key certificate of the information provision processing device 150 stored in the server certificate column of the proxy communication session record. The server public key certificate is acquired and transmitted to the user terminal 110. (Transmission means)

  In step S1121, the user terminal 110 performs verification processing of the received server public key certificate. First, the user terminal 110 verifies the reliability of the server public key certificate with the public key certificate of the trusted CA (certificate authority) stored in the CA certificate storage unit 115 of the user terminal 110. . Next, the user terminal 110 confirms whether the subject information (CN attribute or SubjectAltName attribute) described in the server public key certificate matches the host name of the information provision processing device 150. In addition, the user terminal 110 generally performs processing for verifying the reliability of the server public key certificate, such as expiration date and revocation status confirmation of the server public key certificate.

  Next, in a normal browser, it is the server public key certificate of the relay processing device 120 received in step S1113 that is displayed as the server public key certificate information, but browsing that cooperates with the extended function processing unit 112 The processing unit 111 causes the user to confirm the information of the server public key certificate of the information provision processing device 150 received in step S1120 by displaying the dialog box shown in FIG.

  That is, the browsing processing unit 111 displays a screen (FIG. 15) including information on the server public key certificate of the information provision processing device 150 received in step S1120.

  In addition, the dialog box can be used so that the user can refer to the server public key certificate of the information providing processing device 150 that provides the content being displayed on the browser screen at any time, as well as causing the user to check temporarily. A button for calling a means for confirming the contents of the server public key certificate such as is added on the browser screen. An example of the browser screen is shown in FIG.

  Normally (when the communication method is direct), the identification name (host name) of the information provision processing device 150 that provided the content being displayed is displayed at a location indicated by 1801 in FIG. It is a link to display the server public key certificate. However, in the case of the proxy method of the present invention, the identification name of the relay processing device 120 and information related to the server public key certificate of the relay processing device 120 are displayed here.

  For this reason, in the example of FIG. 18, the identification name of the information provision processing apparatus 150 that is the original content provider and information related to the server public key certificate of the information provision processing apparatus 150 are displayed at a location indicated by 1802. ing. As described above, even if it is a proxy method, the user can check the identification name of the information provision processing device 150 and the information related to the server public key certificate of the information provision processing device 150 at any time, so that the content can be transmitted to the user. Provides a means to confirm information related to the authenticity of the provider.

  Finally, if the verification of the server public key certificate is successful, the user terminal 110 creates a new record in the server certificate cache table (FIG. 17) of the management table storage unit 114, and The server public key certificate, the server identifier of the information provision processing device 150, and the session ID included in the Server Hello message in step S1112 are stored together.

  In step S1122, the user terminal 110 succeeds in verifying the server public key certificate, and notifies the relay processing device 120 of the verification result.

  In step S1123, the relay processing device 120 checks the value in the client authentication request field of the proxy communication session record, and if it is determined that the value is stored in the client authentication request field of the proxy communication session record, in step S1117. It is determined that there has been a request for client authentication from the information providing processing device 150. In order to respond to this (client authentication request), the relay processing device 120 transmits a client certificate request message including the value of the client authentication request field to the user terminal 110.

  In step S1124, when the user terminal 110 receives the client certificate request message from the relay processing device 120, the user terminal 110 searches the encryption key storage unit 113 for a public key certificate that matches the conditions indicated in the client authentication request. get. Then, when there are a plurality of public key certificates that match the above conditions, the user terminal 110 displays a dialog box to the user in the same manner as the operation at the time of SSL client authentication in a normal browser. The public key certificate to be used for authentication to the information provision processing device 150 is selected, and one public key certificate of the user terminal 110 is determined.

  In step S1125, the user terminal 110 transmits the public key certificate of the user terminal 110 to the relay processing device 120.

In step S1126, the relay processing device 120 receives the public key certificate of the user terminal 110 from the user terminal and stores it in the client certificate column of the proxy communication session record. Then, the relay processing device 120 transmits a Client Certificate message including the public key certificate to the information providing processing device 150. In other words, the relay processing device 120 transmits the public key certificate of the user terminal to the information providing processing device 150 via the server line 163 (public key transmitting means).
Next, the relay processing device 120 generates a master secret (information for generating a common key used for data encryption and decryption).

  Also, the relay processing device 120 generates a common key used for encrypting and decrypting data to be communicated with the information providing processing device 150 via the server line 163 according to the master secret generated here. Then, the generated common key is stored in the common key other-S column of the proxy communication session record (FIG. 10).

  When the relay processing device 120 transmits data to the information providing processing device 150 via the server line 163 in the processing after step S1135, the relay processing device 120 encrypts and transmits the data using the common key generated here. To do.

  In addition, the relay processing device 120 decrypts the encrypted data transmitted from the information providing processing device 150 via the server line 163 using the common key generated here.

  Then, the relay processing device 120 encrypts the generated master secret by using the server public key included in the server public key certificate included in the SSL Server Certificate message received from the information providing processing device 150. To do.

Then, the relay processing device 120 transmits a Client Key Exchange message including the encrypted master secret to the information providing processing device 150.
The information provision processing device 150 receives the Client Key Exchange message from the relay processing device 120.

  Then, the information provision processing device 150 transmits the encrypted master secret included in the ClientKeyExchange message to the server public key certificate (server public key included in the SSL Server Certificate message transmitted to the relay processing device 120). Decryption using a secret key corresponding to

  Note that the secret key used here is stored in the server encryption key storage unit 152 in association with the server public key certificate (including the server public key), and the information provision processing device 150 sends the information to the relay processing device 120. It corresponds to the transmitted server public key certificate (including the server public key).

  Next, the information provision processing device 150 generates a common key according to the decrypted master secret. Then, the information providing processing device 150 stores the generated common key information in a memory such as the external memory 211.

  When the relay processing device 120 transmits data to the information providing processing device 150 via the server line 163 in the processing after step S1135, the relay processing device 120 encrypts and transmits the data using the common key generated here. To do.

  In addition, the relay processing device 120 decrypts the encrypted data transmitted from the information providing processing device 150 via the server line 163 using the common key generated here.

  In the SSL (including TLS) protocol, client authentication is performed for information shared by the user terminal 110 and the information provision processing device 150 (message digest of information obtained by concatenating messages exchanged by handshake). The user terminal 110 transmits the signed information (signature data) to the information provision processing device 150. That is, the user terminal 110 provides information (signature data) obtained by signing the message digest with a secret key corresponding to the public key transmitted from the user terminal 110 to the information provision processing device 150 by the SSL Client Certificate message. Transmit to the processing device 150. The information provision processing device 150 decrypts the signature data received from the user terminal 110 with the public key, and is stored in the memory of the information provision processing device 150 and shared with the user terminal 110 Client authentication is performed by determining whether or not (the message digest) is the same.

  In steps S1127 to S1128 described below, the user terminal 110 and the relay processing device 120 cooperate to create signature data.

  In step S <b> 1127, the relay processing device 120 generates a message digest (signature target data) in which a hash function is applied to data obtained by concatenating the messages exchanged with the information providing processing device 150 through the SSL handshake. Then, the relay processing device 120 transmits the signature target data to the user terminal 110.

  The user terminal 110 receives the signature target data from the relay processing device 120, and signs the signature target data with the private key corresponding to the public key certificate of the user terminal 110 transmitted in step S1125 (encryption). To create signature data.

  In step S 1128, the user terminal 110 transmits the signature data to the relay processing device 120. Then, the relay processing device 120 receives the signature data from the user terminal 110.

  In step S <b> 1129, the relay processing apparatus 120 creates an SSL Certificate Verify message including the signature data, and transmits the SSL Certificate Verify message to the information provision processing apparatus 150.

  That is, the relay processing device 120 transmits the signature data generated by encrypting the signature target data using the private key corresponding to the public key certificate of the client terminal transmitted in S1126 via the server line 163. Transmit to the information provision processing device (signature data transmission means).

  Then, the information provision processing device 150 performs client authentication of the user terminal 110 by verifying the message (signature data) received from the relay processing device 120 by the above method.

  In steps S1130 and S1131, the relay processing device 120 and the information providing processing device 150 exchange Handshake finish messages with each other, finish the SSL handshake on the server line 163, and perform server communication 163 that is encrypted communication by SSL. Establish.

  In steps S1132 and S1133, the user terminal 110 and the relay processing device 120 exchange a handshake finish message with each other, the SSL handshake on the proxy line 161 is terminated, and the proxy line 161, which is encrypted communication by SSL. Establish.

  In step S1134, the user terminal 110 relays the encrypted communication request message obtained by encrypting the communication request message corresponding to the content acquisition request generated in step S1101 by the method determined by the SSL handshake on the proxy line 161. Transmit to the processing device 120.

  That is, the user terminal 110 encrypts the communication request message corresponding to the content acquisition request generated in step S1101 using the common key shared with the relay processing device 120, and the encrypted encrypted communication. The request message is transmitted to the relay processing device 120.

  In step S1135, the relay processing device 120 uses the common key (proxy communication session management (FIG. 10) table common other-C) shared with the user terminal 110 for the encrypted communication request message received from the user terminal 110. And a communication request message obtained by the decryption is acquired. Then, the relay processing device 120 executes additional function processing such as access control on the communication request message in the additional function processing unit 130. In this example, it is assumed that access control processing is performed and access is permitted.

  In other words, the relay processing device 120 analyzes the content of the communication request message, performs access control processing by determining whether to permit transmission of the communication request message to the information providing processing device 150, and provides information provision When it is determined that transmission of the communication request message to the processing device 150 is permitted, control is performed so that the communication request message is transmitted to the information providing processing device 150. On the other hand, when it is determined that the transmission of the communication request message to the information provision processing device 150 is not permitted, the relay processing device 120 performs control so that the communication request message is not transmitted to the information provision processing device 150.

Next, an encrypted communication request message is generated by encrypting the communication request message by the method decided by the SSL handshake on the server line 163, and the message is transmitted to the information providing processing device 150.

  That is, when the relay processing device 120 controls to transmit a communication request message to the information providing processing device 150, the relay processing device 120 transmits the communication request message to the information providing processing device 150 using a common key (proxy communication session management ( FIG. 10) is encrypted using a common other in the table-common key stored in S), and an encrypted communication request message generated by the encryption is transmitted to the information provision processing device 150.

  In step S1136, the information provision processing device 150 decrypts the encrypted communication request message received from the relay processing device 120 using the common key shared with the relay processing device 120, and decrypts the communication request message by the decryption. Generate.

  Then, the information provision processing device 150 creates a communication response message as a response message of the communication request message from the relay processing device 120, and encrypts the communication response message using the common key shared with the relay processing device 120. The encrypted communication response message is generated, and the encrypted communication response message is transmitted to the relay processing device 120.

  In step S <b> 1137, the relay processing device 120 uses the common key (proxy communication session management (FIG. 10) table common other shared with the information provision processing device 150) for the encrypted communication response message received from the information provision processing device 150. -A common response key stored in S is decrypted to obtain a communication response message. Then, the relay processing apparatus 120 executes additional function processing such as access control on the communication response message in the additional function processing unit 130.

  That is, the relay processing device 120 performs the access control process by determining whether to permit transmission of the communication response message to the user terminal 110 by analyzing the content of the communication response message. In this example, it is assumed that the relay processing device 120 performs a virus check process in the communication response message as an additional function process, and as a result, no virus is detected in the communication response message.

  When it is determined that the transmission of the communication response message to the user terminal 110 is permitted, the relay processing device 120 controls to transmit the communication response message to the user terminal 110. On the other hand, when it is determined that transmission of a communication response message to the user terminal 110 is not permitted, the relay processing device 120 performs control so that the communication response message is not transmitted to the user terminal 110.

  Next, when the relay processing device 120 controls to transmit the communication response message to the user terminal 110, the encryption is performed by encrypting the communication response message by the method determined by the SSL handshake on the proxy line 161. A communication response message is generated, and the message is transmitted to the user terminal 110.

  That is, when the relay processing device 120 controls to transmit the communication response message to the user terminal 110, the relay processing device 120 transmits the communication response message to the common key (proxy communication session management (see FIG. 10) The encrypted communication response message is generated by encrypting using the common other in the table-common key stored in -C), and the encrypted communication message is transmitted to the user terminal 110.

  The user terminal 110 generates a communication response message by decrypting the encrypted communication response message received from the relay processing device 120 using the common key shared with the relay processing device 120, and the communication response Processing such as displaying a message on the screen of the browsing processing unit 111 is performed.

  In step S1138, the information provision processing device 150 transmits an end notification message by the SSL alert protocol to the relay processing device 120 in order to end the SSL connection.

  In step S <b> 1139, the relay processing device 120 transmits an end notification message to the information providing processing device 150. As a result, the server line 163 is terminated.

  In step S1140, the relay processing device 120 transmits an end notification message based on the SSL alert protocol to the user terminal 110 in order to end the SSL connection.

In step S <b> 1141, the user terminal 110 similarly transmits an end notification message to the relay processing device 120. As a result, the proxy line 161 is terminated.
The procedure for establishing the SSL encrypted communication described above is an example, and the encrypted communication may be established by transmitting / receiving messages other than the messages described above between the devices.

  This is the end of the description of the example of the communication message exchange flow when relaying the communication data communicated via the SSL encrypted communication (line) when the communication method is the proxy method (“proxy”). .

(Communication message exchange flow when encrypted communication by session resumption function is relayed by proxy method)

  Next, the user who relays the encrypted communication data by the proxy method and opens the SSL session by the session resumption function in the SSL connection of the proxy line 161 and the SSL connection of the server line 163 A communication message exchange flow among the terminal 110, the relay processing device 120, and the information provision processing device 150 will be described with reference to FIG.

  FIG. 12 shows a case where data to be encrypted is relayed by a proxy method, and when an SSL session is established by the session resumption function between the SSL connection of the proxy line 161 and the SSL connection of the server line 163 FIG. 10 is a diagram illustrating an example of a communication message exchange flow among the user terminal 110, the relay processing device 120, and the information provision processing device 150.

  The session resuming function is a function for resuming a session that has been opened and ended in the past. When a session is resumed without creating a new session in SSL, a session key ( This is a function used to improve performance because processing with high load related to generation and exchange of a common key can be omitted.

  Note that all communication between the user terminal 110 and the relay processing device 120 in FIG. 12 is performed on the proxy line 161.

  The process in step S1201 is the same as the process in step S1101 described above.

  Next, in the user terminal 110, the process of the extended function processing unit 112 is activated by the event handler registered in the browsing processing unit 111 in response to the content acquisition request in step S1201. The extended function processing unit 112 of the user terminal 110 acquires the schema part of the URL of the content acquisition request, and performs processing for determining the communication method in the relay processing apparatus 120 because the schema is HTTPS. Before making an inquiry to the relay processing device 120, the user terminal 110 checks the client communication method of the management table storage unit 114 in order to check whether information used in communication with the relay processing device 120 in the past is unavailable. Referring to the cache table (FIG. 16), the server identifier (host name: port number) of the information provision processing device 150 is generated from the URL included in the content acquisition request, and the client communication method cache table is set using the server identifier as a key. The record of (FIG. 16) is searched. In this example, as a result of the search, the user terminal 110 finds a record that satisfies the server identifier as a condition, refers to the communication method column of the record, and determines that the communication method is “proxy”. If the communication method is determined to be “direct” as a result of the search, the user terminal 110 and the information provision processing device 150 directly connect the SSL encrypted communication line using the normal method (direct method). Control to establish.

  In step S1202, the user terminal 110 performs the same process as in step S1107 described above.

  In step S1203, the relay processing apparatus 120 performs the same process as in step S1108 described above.

  In step S1204, the relay processing apparatus 120 performs the same process as in step S1109 described above.

In step S1205, the browsing processing unit 111 of the user terminal 110 determines that it can be restarted because the SSL session information used in the past communication with the information providing processing device 150 is cached, and is cached. A Client Hello message to which the session ID of the session information is added is transmitted to the relay processing device 120.
The browsing processing unit 111 of the user terminal 110 determines whether or not the SSL session information used in the past communication to the information providing processing device 150 is cached. As a result, the SSL session information is not cached. If it is determined, as described in step S1110 of FIG. 11, an SSL Client Hello message without a session ID is transmitted to the relay processing device 120.

  In step S1206, the relay processing apparatus 120 displays the client identifier and server identifier received in step S1202 (step S1107) from the proxy communication method cache table (FIG. 9) of the management table storage unit 129, respectively, in the client identifier field. A record held in the server identifier field is acquired, and it is determined (determined) that the relay is performed in the proxy system from the value (“proxy”) in the communication system field of the record.

  Next, the relay processing device 120 displays the client identifier and server identifier received in step S1202 (step S1107) from the proxy communication session management table (FIG. 10) of the management table storage unit 129, respectively, in the client identifier field and server. A record (called proxy communication session record) in the identifier field is acquired. The proxy communication session management table (FIG. 10) is an application example of proxy communication storage means.

  The relay processing device 120 refers to the session ID-C column of the proxy communication session record, and if the same as the session ID (first session identification information) of the SSL Client Hello message received from the user terminal 110, the relay processing device 120 The device 120 also determines that session resumption is possible (determination means).

  That is, the relay processing device 120 determines whether or not the value in the session ID-C column of the proxy communication session record is the same as the session ID included in the SSL Client Hello message received from the user terminal 110, When it is determined that they are the same, the relay processing device 120 also determines that the session can be resumed. On the other hand, when the relay processing device 120 determines that the value in the session ID-C column of the proxy communication session record is not the same as the session ID included in the SSL Client Hello message received from the user terminal 110, The relay processing device 120 determines that the session cannot be resumed. Here, when it is determined that the session cannot be resumed, the relay processing device 120 does not perform the subsequent processing. In this example, it is determined that the session can be resumed, and an SSL Server Hello message with the session ID added is transmitted to the user terminal 110.

  In step S1207, the relay processing device 120 determines whether or not there is a session ID value in the session ID-S column of the proxy communication session record, and sets the session ID (second ID) in the session ID-S column of the proxy communication session record. If it is determined that there is a value of the session identification information), it is determined that the session can be resumed also on the server line 163, and the Client Hello message to which the session ID is added is transmitted to the information providing processing device 150. . On the other hand, when it is determined that there is no session ID value in the session ID-S column of the proxy communication session record, the relay processing device 120 determines that the session cannot be resumed on the server line 163, and this Control is performed so that subsequent processing is not executed.

  In step S <b> 1208, the information provision processing apparatus 150 confirms that the SSL session information identified by the session ID received from the relay processing apparatus 120 can be used also in the information provision processing apparatus 150, and then transmits the information to the relay processing apparatus 120. Then, a Server Hello message with the session ID added is responded. This means that the session resumption agreement has been reached also in the SSL connection of the server line 163 between the relay processing device 120 and the information provision processing device 150.

  In step S1209, the information provision processing device 150 transmits an SSL Handshake finished message to the relay processing device 120.

  In step S <b> 1210, the relay processing device 120 transmits an SSL Handshake finished message to the information providing processing device 150.

  With the above, the SSL handshake process of the server line 163 between the relay processing device 120 and the information providing processing device 150 is completed.

  In step S1211, the relay processing device 120 transmits a Handshake finished message to the user terminal 110.

  In step S <b> 1210, the user terminal 110 transmits a Handshake finished message to the relay processing device 120.

  Thus, the SSL handshake process of the proxy line 161 between the user terminal 110 and the relay processing device 120 is finished.

  Thereafter, the same processing as that from step S1134 to step S1141 described with reference to FIG. 11 is performed by the processing from step S1213 to step S1220 in FIG.

  This is the end of the description of the example of the communication message exchange flow when the encrypted communication by the session resuming function is relayed by the proxy method.

  As described above, in the relay process using the session resumption function, the SSL handshake process can be significantly shortened, and a process with a high calculation load can be omitted. Further, according to the procedure described above, even when the session resuming function is used, the user terminal 110 performs the server certificate cache of the management table storage unit 114 at the time of communication for establishing a session (step S1121 in FIG. 11). By referring to the server certificate column stored in the table, the server public key certificate of the information providing processing device 150 can be presented to the user without being transmitted from the relay processing device 120. It is possible to give a person a means for confirming the authenticity of the communication partner. Regarding the client authentication, the information provision processing device 150 caches the public key certificate of the user terminal 110 in the session information stored in the memory of the information provision processing device 150, and therefore relays again. Transmission of client authentication request information to the processing device 120 and verification processing can also be omitted.

(Communication processing flow in the relay processing device 120)

  Next, the processing flow of the relay processing device 120 when the user terminal 110 performs encrypted communication (encrypted communication using a proxy method) to the information providing processing device 150 via the relay processing device 120 will be described with reference to FIG. I will explain.

  Note that steps S301 to S320 illustrated in FIG. 3 are realized by the CPU 201 of the relay processing device 120 executing.

  In step S301, the relay processing device 120 performs processing (communication method determination processing) for determining a communication method based on the generation of a request for encrypted communication from the user terminal 110 to the information providing processing device 150 (FIG. 11). Step S1101 to step S1106).

  In the communication method determination process, the communication method in the relay processing device 120 for communication requested by the user terminal 110 is determined, and the determined communication method is communicated to the proxy communication method cache table (FIG. 9) of the management table storage unit 129. A new record is created in the method field. The value of the communication method column of the record is either “direct”, “proxy”, or “no selection”. Details of the processing will be described later with reference to FIG.

In step S302, the client communication unit 121 accepts a connection from the browsing processing unit 111 of the user terminal 110, and receives a connection request message (the information providing processing device 150 and the information providing processing device 150) using the CONNECT method according to the SSL (including TLS) proxy connection protocol. (SSL communication request information) and the connection request message is passed to the communication control unit 124 (step S1107 in FIG. 11).
That is, the relay processing device 120 receives a request for SSL communication from the user terminal 110 to the information providing processing device 150 (receiving unit).

  In other words, the relay processing device 120 controls to start establishment of the proxy line 161 and establishment of the server line 163 on the condition that the SSL communication request is received from the user terminal 110 (control unit).

  Hereinafter, a connection line established between the client communication unit 121 of the relay processing device 120 and the browsing processing unit 111 of the user terminal 110 is referred to as a proxy line 161.

  Next, the communication control unit 124 creates a server identifier (host name: port number) from the host name and port number of the information provision processing device 150 specified by the CONNECT method of the connection request message, and also generates the connection request message. The client identifier (IP address: browsing processing unit identifier) is acquired from the request header. Then, the communication control unit 124 searches for a record from the proxy communication method cache table (FIG. 9) of the management table storage unit 129 using the server identifier and the client identifier as keys, and sets the search result and the communication method of the record. get. The communication method is the value stored in step S301.

  When the communication method is “direct” or “proxy”, the communication control unit 124 passes the host name and port number passed by the CONNECT method to the server communication unit 122, and the server communication unit 122 To the port number of the information provision processing device 150 (step S1108 in FIG. 11). If the connection fails, the communication control unit 124 responds (sends) an error message to the user terminal 110 via the client communication unit 121 and ends. If the connection is successful, the communication control unit 124 returns an HTTP response code 200 to the user terminal 110 via the client communication unit 121 (step S1109 in FIG. 11). Hereinafter, a connection line established between the server communication unit 122 of the relay processing device 120 and the server processing unit 151 of the information provision processing device 150 is referred to as a server line 163.

  Further, when the communication method is “proxy”, the communication control unit 124 searches for a record from the proxy communication session management table (FIG. 10) of the management table storage unit 129 using the server identifier and the client identifier as keys. To do. If there is no record matching the key, the communication control unit 124 creates a new record having a server identifier and a client identifier in the server identifier column and the client identifier column, respectively. The communication control unit 124 stores the record found by the search or the newly created record in the RAM 203 of the relay processing device 120. Hereinafter, this record is called a proxy communication session record and can be referred to in the communication control unit 124.

  In step S303, the process is branched according to the communication method acquired in step S302. That is, the relay processing apparatus 120 determines whether the communication method acquired in step S302 is “direct”, “proxy”, or “no selection”. If the communication method is “direct”, the process proceeds to step S304. If it is “proxy”, the process proceeds to step S305. If it is “not selected”, the process proceeds to step S319.

(Direct proxy processing)
In step S304, data to be encrypted (HTTPS communication) is relayed by a method (direct method) performed by a normal proxy server.

  That is, the relay processing device 120 relays data transmitted and received between the user terminal 110 and the information provision processing device 150 through the data. Thereby, the encryption communication (3rd SSL communication) by SSL is established between a client terminal and information processing apparatus like the past.

  The relay processing device 120 relays communication data communicated between the user terminal 110 and the information provision processing device 150 using the encrypted communication established here.

  After the communication control unit 124 responds the HTTP response code 200 to the user terminal 110 in step S302, the communication control unit 124 receives all encrypted communications that the client communication unit 121 receives from the browsing processing unit 111 of the user terminal 110. The message (encrypted data) is transmitted as it is from the server communication unit 122 to the server processing unit 151 of the information provision processing device 150. In addition, the communication control unit 124 sends all encrypted communication messages (encrypted data) received by the server communication unit 122 from the server processing unit 151 of the information providing processing device 150 from the client communication unit 121 to the user. It transmits to the browsing processing part 111 of the terminal 110. Then, when either the server line 163 is disconnected from the information provision processing device 150 or the proxy line 161 is disconnected from the user terminal 110, the communication control unit 124 disconnects the opposite communication line. All processing is terminated.

  In the relay processing by the direct method, both the communication request message and the communication response message are relayed while being encrypted. Therefore, when passing through the communication control unit 124, the relay processing device 120 adds the additional function in the additional function processing unit 130. Processing (communication message check, communication response cache, etc.) is not executed.

(Relay rejection notification)
In step S319, the communication control unit 124 creates a communication response message indicating that access is not permitted, and transmits the communication response message to the browsing processing unit 111 of the user terminal 110 via the client communication unit 121. The line 161 is disconnected and the process ends.

(Proxy method: SSL handshake processing with the user terminal 110)

  In step S305, the communication control unit 124 instructs the client side encryption processing unit 123 to start an SSL session on the proxy line 161. The client side encryption processing unit 123 receives the SSL Client Hello message transmitted from the browsing processing unit 111 of the user terminal 110 via the client communication unit 121 in the proxy line 161, and starts the SSL handshake process. . There are two SSL handshake methods: a case where a session is newly started and a case where a past session is restarted.

  First, a case where a session is newly started will be described.

  The relay processing device 120 determines whether or not a session ID is included in the SSL Client Hello message, and when it is determined that the session ID is included, the session ID is the proxy communication When it is determined that the value is the same as the value in the session ID-C column of the session record, the session is resumed with the SSL connection on the client side. To do.

  That is, in the process of newly starting an SSL session, the client-side cryptographic processing unit 123 of the relay processing device 120 responds to the SSL Client Hello message (step S1110 in FIG. 11) transmitted from the user terminal 110 in response to the server. Each message of Hello, Server Certificate, and Server Hello Done is sequentially transmitted (step S1112, step S1113, and step S1114 in FIG. 11).

  Specifically, when it is determined that the session ID is not included in the SSL Client Hello message, the relay processing device 120 generates a new unique session ID in order to create a new session.

  Then, the relay processing device 120 transmits the SSL Server Hello message including the generated session ID to the user terminal 110, and stores the generated session ID in the session ID-C column of the proxy communication session record. . The session ID becomes an identifier when the session is resumed after the next time.

  Upon receiving the SSL Server Hello message including the session ID from the relay processing device 120, the user terminal 110 stores the session ID included in the SSL Server Hello message in a memory such as the RAM 203 as SSL session information (cache). To do).

  Next, the relay processing device 120 transmits an SSL Server Certificate message including the server public key certificate stored in the proxy encryption key storage unit to the user terminal 110 (step S1113).

  The user terminal 110 receives the SSL Server Certificate message from the relay processing device 120 and stores the server public key certificate included in the SSL Server Certificate message in a memory such as the external memory 211.

  Then, the relay processing device 120 transmits an SSL Server Hello Done message notifying the end of a series of processing in the relay processing device 120 to the user terminal 110 (step S1114).

  Upon receiving the SSL Server Hello Done message from the relay processing device 120, the user terminal 110 generates a master secret (information for generating a common key used for data encryption and decryption).

  Further, the user terminal 110 generates a common key used to encrypt and decrypt data to be communicated with the relay processing device 120 via the proxy line 161 according to the master secret generated here. The generated common key is stored in a memory such as the RAM 203.

  When the user terminal 110 transmits data to the relay processing device 120 via the proxy line 161 in the processing after step S1134 (step S314), the user terminal 110 encrypts the data using the common key generated here. And send it.

  Also, the user terminal 110 decrypts the encrypted data transmitted from the relay processing device 120 via the proxy line 161 using the common key generated here.

  Then, the user terminal 110 encrypts the generated master secret using the server public key included in the server public key certificate included in the SSL Server Certificate message received from the relay processing device 120. .

Then, the user terminal 110 transmits a Client Key Exchange message including the encrypted master secret to the relay processing device 120.
The relay processing device 120 receives the Client Key Exchange message from the user terminal 110.

  Then, the relay processing device sends the server public key certificate (including the server public key) included in the SSL Server Certificate message transmitted to the user terminal 110 to the encrypted master secret included in the Client Key Exchange message. The private key corresponding to is decrypted.

  The secret key used here is stored in the proxy encryption key storage unit 126 in association with the server public key certificate (including the server public key), and is transmitted to the user terminal 110. It corresponds to the certificate (including the public key of the server).

  Next, the relay processing device 120 generates a common key according to the decrypted master secret. Then, the relay processing device 120 stores the generated common key information in the common key and other-C column of the proxy communication session record.

  When the relay processing device 120 transmits data to the user terminal 110 via the proxy line 161 in the processing after step S1134 (step S314), the relay processing device 120 encrypts the data using the common key generated here. And send it. Further, the relay processing device 120 decrypts the encrypted data transmitted from the user terminal 110 via the proxy line 161 using the common key generated here.

  Next, a case where the SSL session is resumed will be described.

  The relay processing device 120 determines that the session ID is included in the SSL Client Hello message received from the user terminal 110, and the session ID is included in the session ID-C column of the proxy communication session record. If it is determined, the SSL session is determined to be resumed (S306: YES). Here, the fact that the relay processing device 120 has received the SSL Client Hello message including the session ID from the user terminal 110 means that a request for resuming SSL communication has been received. At this time, the common key for the SSL session is already stored in the common key and other-C column. In response to the SSL Client Hello message (step S1205 in FIG. 12) from the user terminal 110, the client side encryption processing unit 123 transmits a Server Hello message (step S1206 in FIG. 12).

(About the server public key certificate of the proxy encryption key storage unit 126)

  The server public key certificate stored in the proxy encryption key storage unit 126 will be described. The server public key certificate is a server public key certificate for server authentication in the SSL connection of the proxy line 161. In a normal proxy connection (direct communication), the server public key certificate is stored in the server encryption key storage unit 152 of the information provision processing device 150 from the information provision processing device 150. Although presented, in the proxy method of the present embodiment, the server public key certificate stored in the proxy encryption key storage unit of the relay processing device 120 is presented instead. Therefore, the server public key certificate must be determined to be valid for an arbitrary information provision processing device 150. For this reason, in the proxy method of the present embodiment, as shown in Non-Patent Document 1, the server public key certificate is the subject's Common Name (CN) in which the host name of the information provision processing device 150 is described. ) A wildcard is used for the attribute or the SubjectAltName attribute to represent an arbitrary information provision processing device 150. The method of confirming the identity of the information provision processing device 150 based on the server public key certificate and the host name is described in RFC 2818 “3. End point identification 3.1 Server identity”.

  In addition, the server public key certificate has the host name of the relay processing device 120 as an attribute value in the hierarchy above the Common Name in the DN (identification name) of the subject, and the endpoint (information provision) Confirmation of the relay point (relay processing device 120) can be performed simultaneously with confirmation of the processing device 150).

An example of DN (subject identifier) is shown.
cn = *. *. *, Ou = proxy. xxx. com, o = XXX Inc. , C = jp

  In this example, cn is represented by a wild card and represents a proxy server public key certificate for an arbitrary information provision processing device 150 having three domain components in the host name. In the proxy encryption key storage unit 126, a server public key certificate whose wild card domain component has cn corresponding to 2 to 10, for example, so that it can be used as a server public key certificate of an arbitrary information provision processing device 150 Are stored in advance, and an appropriate one is selected from the server public key certificates according to the number of domain components of the host name of the information providing processing device 150 in the communication session.

  In addition, the host name of the relay processing device 120 (the above example: proxy.xxx.com) is described as the ou attribute value one level higher than Common Name (cn). The ou attribute value can be used for authenticity confirmation of the relay processing device 120 in the SSL connection on the proxy line 161. This can be verified by checking that the attribute value is the same as the host name of the relay processing device 120 to which the extended function processing unit 112 of the user terminal 110 is explicitly connected via the control line 162.

  In step S306, if a new session is established in step S305, the process proceeds to step S307, and if the session resuming function is used, the process proceeds to step S316.

  In step S307, the server-side cryptographic processing unit 125 transmits an SSL Client Hello message to the information providing processing device 150 via the server communication unit 122 via the server line 163 opened in step S302, and performs SSL handshake processing. Is newly started (step S1111 to step S1118 in FIG. 11).

  The server-side encryption processing unit 125 receives an SSL Server Hello, an SSL Server Certificate, an SSL Certificate Request (optional), an SSL Server Hello Done message, and the like from the information providing processing device 150. When receiving the SSL Server Certificate message, the communication control unit 124 acquires the server public key certificate of the information providing processing device 150 included in the message, and uses the server public key certificate in the server certificate field of the proxy communication session record Save to.

Further, when the server-side cryptographic processing unit 125 receives the Certificate Request message (step S1117 in FIG. 11), it means that the information providing processing device 150 requests SSL client authentication. Therefore, the communication control unit 124 Encodes and saves the contents of the Certificate Request message in the client authentication request field of the proxy communication session record. The Certificate Request message includes a signature algorithm indicating client authentication conditions and root CA identification name information trusted by the information providing processing device 150.

  In step S308, the control processing communication unit 128 transmits the server public key certificate of the information provision processing device 150 stored in the server certificate column of the proxy communication session record to the user terminal 110 via the control line 162, In this step, the server public key certificate is verified in the user terminal 110 and server authentication is performed on the information provision processing device 150. Then, the control processing communication unit 128 passes the verification result to the communication control unit 124 (step S1119 to step S1122 in FIG. 11). Detailed processing in step S308 will be described later with reference to FIG.

  In step S309, the communication control unit 124 proceeds to step S310 if the result of the server authentication processing in step S308 passed from the control processing communication unit 128 is successful, and proceeds to step S320 if it is unsuccessful. Here, if the communication control unit 124 receives a notification that the verification is successful from the user terminal 110 in step S308, the communication control unit 124 determines that the result of the server authentication processing is successful. Is received, the server authentication processing result is determined as failure.

  In step S310, the communication control unit 124 refers to the client authentication request field of the proxy communication session record. If a value exists, the process proceeds to step S311. If no value exists, the process proceeds to step S312.

  In step S311, the relay processing device 120 performs processing for responding to the client authentication requested from the information providing processing device 150 in cooperation with the user terminal 110 (step S1123 to step S1129 in FIG. 11). Detailed processing in step S311 will be described later with reference to FIG.

  In step S312, the server-side cryptographic processing unit 125 transmits an SSL Handshake finished message to the information providing processing device 150 via the server communication unit 122, and ends the handshake process of the SSL connection in the server line 163. (Step S1130 to Step S1131 in FIG. 11).

  In step S313, the client-side encryption processing unit 123 transmits SSL Handshake finished to the user terminal 110 via the client communication unit 121, and the SSL connection handshake processing in the proxy line 161 is terminated (FIG. 11). Step S1132 to Step S1133).

  In step S314, the application message is relayed between the two SSL sessions, the already established SSL session of the proxy line 161 and the SSL session of the server line 163. At this time, processing by the additional function is executed on the message plainly written in the additional function processing unit 130 (step S1134 to step S1137 in FIG. 11). Details will be described later.

  In step S315, when the exchange of the application message in step S314 ends, a session end notification by an SSL close notification message is transmitted from the information providing processing device 150 or the user terminal 110. When the client-side encryption processing unit 123 or the server-side encryption processing unit 125 receives the message, the client-side encryption processing unit 123 or the server-side encryption processing unit 125 returns an SSL close notify message, ends the SSL session, and sets the communication line ( Disconnect proxy line or server line). Next, an SSL session termination process on the opposite side and a communication line (proxy line or server line) disconnection process are performed.

(When using the SSL session resume function)
In step S316, the communication control unit 124 determines whether or not the SSL session can be resumed on the server line 163.

  That is, the communication control unit 124 determines whether there is a value in the session ID-S field of the proxy communication session record including the session ID received from the user terminal 110, and determines the session of the proxy communication session record. When it is determined that a value exists in the ID-S column, an SSL Client Hello message to which the session ID value is added is provided from the server-side cryptographic processing unit 125 via the server communication unit 122 via the server line Transmit to the processing device 150.

  Next, the server-side cryptographic processing unit 125 receives an SSL Server Hello message from the information provision processing device 150. The communication control unit 124 determines whether or not the session ID is included in the SSL Server Hello message. If it is determined that the session ID is included, the communication control unit 124 determines that the session can be resumed, and step S312. Proceed to

  If there is no value in the session ID-S field of the proxy communication session record, or if the SSL is not included in the SSL Server Hello message, the communication control unit 124 determines that the session cannot be resumed. The process proceeds to step S317.

  In step S317, the communication control unit 124 starts a new SSL session on the server line 163, similarly to step S307.

  Upon receiving the SSL Server Certificate message from the information provision processing device 150, the communication control unit 124 acquires a server public key certificate from the message, and stores the server public key certificate and the server certificate column of the proxy communication session record. Compare the value. As a result of the comparison, if both are not the same, the server certificate field of the proxy communication session record is overwritten and saved with the server public key certificate.

  In addition, when receiving the SSL Certificate Request message from the information providing processing device 150, the communication control unit 124 encodes the content of the SSL Certificate Request message in the client authentication request field of the proxy communication session record as in Step S307. save.

  In step S318, the communication control unit 124 refers to the result of the server public key certificate comparison in step S317. If true (identical), the process proceeds to step S310, and if false (not identical), the server public key certificate is again obtained. The process proceeds to step S308 in order to verify the document on the user terminal 110.

(Error handling)
In step S320, the control processing communication unit 128 notifies the communication control unit 124 that the server certificate verification processing in step S308 has failed, and the communication control unit 124 notifies the server side cryptographic processing unit 125 of the information providing processing device. 150, the server-side cryptographic processing unit 125 notifies the SSL hand certificate alert message of SSL via the server communication unit 122 and the server line 163 to provide information. The data is transmitted to the apparatus 150, the server line 163 is disconnected, and the process ends.

(Fig. 4 Details of communication method decision processing)
Next, the flow of communication method determination processing between the user terminal 110 and the relay processing device 120, which is the details of step S301 in FIG. 3, will be described with reference to FIG.

  The processing from step S 401 to step S 403 and step S 406 to step S 408 shown in FIG. 4 is executed and implemented by the CPU 201 of the user terminal 110.

  Further, the processing of step S404, step S405, and step S409 is executed and implemented by the CPU 201 of the relay processing device 120.

  It is assumed that the communication between the user terminal 110 and the relay processing device 120 shown in FIG. 4 uses the control line 162 in FIG.

  In step S401, the browsing processing unit 111 of the user terminal 110 allows the user to click on a URL link in the “https: // ...” format or input it to the address bar, etc. When a request event of encrypted communication to 150 is detected, the URL is passed to the extended function processing unit 112 and control is transferred.

  In step S402, the extended function processing unit 112 of the user terminal 110 generates a server identifier (site information) from the host name and port number in the URL, and the management table storage unit 114 client uses the server identifier as a key. A record is retrieved from the communication method cache table (FIG. 16).

  If there is a record that matches the conditions in the search process, the extended function processing unit 112 of the user terminal 110 sets the value in the communication method column of the record as the communication method and ends the process. In this case, if the record (cache information) of the client communication method cache table of the user terminal 110 exists, the proxy communication method cache table (FIG. 9) of the relay processing device 120 also has cache information of the same communication condition. To do.

  If there is no record that matches the conditions in the search process, the extended function processing unit 112 of the user terminal 110 proceeds to step S403 to determine a new communication method.

  In step S403, the extended function processing unit 112 of the user terminal 110 connects to the control processing communication unit 128 of the relay processing device 120 via HTTPS. That is, an encrypted communication line (control line 162) using SSL is established between the user terminal 110 and the relay processing device 120. This connection line is called a control line 162. The extended function processing unit 112 of the user terminal 110 relays the communication method inquiry request message having the server identifier generated in step S402 and the client identifier including the IP address of the user terminal 110 and the browsing processing unit 111 identifier. Transmit to device 120.

  In step S404, the control processing communication unit 128 of the relay processing device 120 receives the communication method inquiry request message in step S403, and acquires a server identifier and a client identifier (accepting means). The server identifier is an application example of relay destination information. The client identifier (IP address) is an application example of client information.

  In step S405, the control processing communication unit 128 of the relay processing device 120 obtains the server identifier for identifying the information provision processing device 150 acquired in step S404 and the client identifier for identifying the browsing processing unit 111 of the user terminal 110. Originally, a record that matches the server condition and the client condition in the communication method determination table (communication method setting information) (FIG. 8) of the management table storage unit 129 is searched, and the communication method for establishing the matching record communication method is permitted. (Communication determination means).

  In the comparison with the domain name field of the server condition, the host name of the information provision processing device 150 is extracted from the server identifier, and character string pattern matching is performed on the value of the host name and the domain name field. For matching with the category field of the server condition, the host name (domain name) is converted into a category. Here, using a conversion table or the like in which a host name (domain name) and a category are associated with each other (not shown), a category corresponding to the host name is calculated (determined) from the host name extracted from the server identifier, The category and the value in the category column are compared. In the collation of the client condition address column, the IP address is extracted from the client identifier, and the IP address and the value are collated. The verification of the authentication group column of the client condition is performed by checking the attribute value of the user input when the relay processing device 120 authenticates the user of the browsing processing unit 111 of the user terminal 110. Although means for authenticating a user who uses the browsing processing unit 111 of the user terminal 110 is not described in detail, for example, means for performing HTTP proxy authentication on the proxy line 161 or a control line Means for performing SSL client authentication, HTTP digest authentication, and the like in the 162 HTTPS transaction can be used.

  In the communication method determination table, a record that matches all the communication request conditions as indicated by 804 in FIG. 8 is provided so that the communication method is always determined.

  That is, the communication method determination table (FIG. 8) has a priority order for determining the condition of each record, and whether the condition of each record is met sequentially from the top record to the bottom record. Judgment is made.

  Next, the control processing communication unit 128 transmits the value of the communication method column of the record obtained as a result of the search to the extended function processing unit 112 of the user terminal 110 as a response message.

  Here, the relay processing device 120 transmits the value (“direct” or “selection” or “proxy”) in the communication method column of the obtained record to the user terminal 110, and the user terminal 110 The screen shown in FIG. 13 or FIG. 14 to be described later is displayed according to the value of the communication method column received from 120.

  As another method, the screen information for displaying the screen shown in FIG. 13 or FIG. 14 determined according to the value (“direct”, “select”, or “proxy”) in the communication method column of the obtained record is relayed. The user terminal 110 that transmits the processing device 120 to the user terminal 110 and receives the screen information may display the screen of FIG. 13 or 14 according to the screen information.

  That is, the relay processing device 120 selects “selection (information indicating that the communication method is selected)” (“selection” for the received site information (relay destination information) (host name or port number identifying the information providing processing device 150). "" Is an application example of the instruction information), when it is determined that the communication method determination table (FIG. 8) is stored, screen information (FIG. 14) for selecting the communication method (direct or proxy) is displayed. Then, the data is transmitted to the user terminal via the control line (communication method transmission means) (step S405). The screen information or the communication method transmitted here is an application example of the communication method instruction information.

In addition, the relay processing device 120 receives information indicating that the communication method is a proxy for the received site information (relay destination information) (host name or port number that identifies the information providing processing device 150). When it is determined that the information is stored in FIG. 8), screen information (FIG. 13) for selecting a communication method (“proxy” or “not communicate”) is transmitted to the user terminal via the control line. (Step S405).
In step S <b> 406, the extended function processing unit 112 of the user terminal 110 receives screen information for selecting a communication method from the relay processing device 120.

  That is, when the user terminal 110 receives screen information from the relay processing device, the user terminal 110 displays the screen shown in FIG. 13 or FIG. 14 according to the screen information. FIG. 14 shows an application example of the instruction screen. As described above, whether the user (operating user) operating the user terminal 110 communicates using the proxy communication method when “proxy” (proxy communication method) is determined as the communication method permitted to be established. In this case, only the selection of whether to perform communication itself can be performed, and the proxy communication method is always selected in order to perform communication. That is, the relay processing device 120 establishes communication using the proxy communication method on the condition that the proxy communication method is determined as the communication method permitted to be established.

  Next, the relay processing device 120 transmits the value (“direct”, “selection”, or “proxy”) in the communication method column of the obtained record to the user terminal 110, and the user terminal 110 receives the relay processing device. The case where the screen shown in FIG. 13 or FIG. 14 is displayed according to the value of the communication method column received from 120 will be described.

  In step S <b> 406, the extended function processing unit 112 of the user terminal 110 receives the communication method (directly or proxy or selection) from the relay processing device 120.

  In step S407, the extended function processing unit 112 of the user terminal 110 displays the dialog box shown in FIG. 13 or FIG. 14 based on the communication method value received in step S406.

  At this time, if the communication method is "direct", the dialog box is not displayed. That is, when the communication method is “direct” (direct communication method), the communication method to be established is “direct” (direct communication method).

  If the communication method received in step S406 is “proxy”, the user terminal 110 displays a dialog box (screen) as shown in FIG. 13 and provides the user with “user terminal 110 and information”. The encrypted communication between the processing devices 150 is once decrypted in the relay processing device 120, and a message that “additional function processing such as a security check is applied” is displayed to select whether or not to accept. In the user terminal 110, when the user clicks the “permit” button on the screen of FIG. 13, the extended function processing unit 112 leaves the communication method as “proxy” and clicks the “not permitted” button. The communication method is updated to a value of “no selection”.

  When the communication method received in step S406 is “selection”, the user terminal 110 displays a dialog box (screen) as shown in FIG. 14 and informs the user of the user terminal 110 and information provision processing. Encrypted communication between the devices 150 is once decrypted in the relay processing device 120 and additional function processing such as security inspection is executed, or end-to-end encrypted communication is performed with the information providing processing device 150 and relayed. The processing device 120 selects whether or not the plain culture communication message can be inspected or recorded. When the user clicks the “permit” button on the screen of FIG. 14, the user terminal 110 updates the communication method in the extended function processing unit 112 to a value of “proxy”, and sets the “not permitted” button. When clicked, the communication method is updated to a value of “direct”.

  Next, the extended function processing unit 112 creates a new record including a server identifier, a determination date and a value of the selected communication method, in the client communication method cache table (FIG. 16) of the management table storage unit 114.

  In step S408, when the button selected by the user is the “permit” button (that is, when the communication method is “proxy”), the extended function processing unit 112 of the user terminal 110 performs the relay processing device 120. Connect to the control processing communication unit 128 by HTTPS (open control line 162).

  Further, when the button selected by the user via the screen of FIG. 14 is a “not permitted” button (that is, when the communication method is “direct”), the extended function processing unit 112 sets the control line 162 to Do not open. Further, when the button selected by the user via the screen of FIG. 13 is a “not permitted” button (that is, when the communication method is “no selection”), the extended function processing unit 112 controls the control line 162. Will not open.

  Then, the extended function processing unit 112 of the user terminal 110 includes the server identifier, the client identifier, the value of the communication method selected in step S407, and the expiration date in the relay processing device 120 of the communication method determined in step S407. , And a communication method notification message having “” are transmitted to the relay processing device 120.

  The expiration date is expressed as an expiration date that can be used on the relay processing apparatus 120 of the communication method, and a date and time advanced about several hours (predetermined time) from the processing date and time in step S407 is used.

  In step S409, the control processing communication unit 128 of the relay processing device 120 receives the communication method notification message (selection result) in step S408 (communication method receiving means), and includes the server identifier and the client included in the communication method notification message. A record including the identifier, the determined communication method, and the expiration date is created, and the record is stored in the proxy communication method cache table (FIG. 9) of the management table storage unit 129. Thus, the communication method determination process is completed.

(Figure 5 Details of server certificate verification process)
Next, the flow of the server certificate verification process in the user terminal 110 and the relay processing device 120, which is the details of step S308 in FIG. 3, will be described with reference to FIG.

  The processes in steps S503 and S505 to S507 shown in FIG. 5 are executed and implemented by the CPU 201 of the user terminal 110.

  Further, the processing of step S501, step S502, step S504, and step S508 is executed and implemented by the CPU 201 of the relay processing device 120.

  Note that the communication between the user terminal 110 and the relay processing device 120 shown in FIG. 5 uses the control line 162 in FIG.

  In step S501, the communication control unit 124 of the relay processing device 120 acquires the server public key certificate of the information providing processing device 150 from the server certificate column of the proxy communication session record, and checks the validity of the server public key certificate. Validate.

  The verification items include whether the signing authority (CA) in the certification path of the server public key certificate matches that stored in the CA certificate storage unit 131 as a trusted signing authority, Is the validity period of the certificate, the revocation status by CRL or OCSP (Online Certificate Status Protocol), the length of the certification path, and the like.

  In step S502, the relay processing apparatus 120 determines whether or not the verification of the server public key certificate in step S501 has succeeded. If it is determined to be successful, the processing proceeds to step S504 and is determined to have failed. If there is, the result information of failure is notified to the communication control unit 124 and the process ends.

  In step S503, the extended function processing unit 112 of the user terminal 110 connects to the control processing communication unit 128 of the relay processing device 120 via HTTPS via the control line 162, and the server identifier of the information providing processing device 150 and the user are connected. A server public key certificate acquisition request message of the information provision processing device 150 is transmitted together with the client identifier of the terminal 110 (step S1119 in FIG. 11).

  In step S504, the control processing communication unit 128 searches the proxy communication session management table of the management table storage unit 129 for a record that matches the key, using the server identifier and client identifier sent in step S501 as keys. . Then, the control processing communication unit 128 acquires a matching record (proxy communication session record) from the proxy communication session management table of the management table storage unit 129. Then, the server certificate field value of the record is responded (transmitted) to the extended function processing unit 112 of the user terminal 110 (step S1120 in FIG. 11) (transmitting means).

  That is, the relay processing device 120 uses the server public key certificate of the information provision processing device 150 (acquired from the information provision processing device 150) used when establishing the encrypted communication line of the server line 163 as the control line 162. To the user terminal 110 via

  In step S505, the extended function processing unit 112 verifies the validity of the server public key certificate received in step S503 (step S1121 in FIG. 11). As a verification means, verification similar to the verification of the server certificate performed during the SSL handshake by the browsing processing unit 111 is performed. As a check item, whether or not the signing authority (CA) in the certification path of the server public key certificate matches that stored in the CA certificate storage unit 115 as a trusted signing authority, Is the validity period of the certificate, the revocation status by CRL or OCSP (Online Certificate Status Protocol), the length of the certification path, and the like. Further, the extended function processing unit 112 checks whether or not the subject name in the server public key certificate matches the host name of the information providing processing device 150 (RFC2818 “3. End point identification 3.1 Server Identity ”).

  In step S506, the extended function processing unit 112 displays the verification result performed in step S503 and the contents of the server public key certificate using a dialog box, and communicates with the user by trusting the server public key certificate. It is confirmed whether or not to continue (step S1121 in FIG. 11). FIG. 15 shows an example of a dialog box.

  The extended function processing unit 112 determines whether or not the “permit” button in the screen illustrated in FIG. 15 has been pressed. If it is determined that the button has been pressed, the extended function processing unit 112 relays that the verification is successful as a confirmation result. The data is transmitted to the control processing communication unit 128 of the processing device 120. On the other hand, when it is determined that the “permit” button has not been pressed and the “not permit” button has been pressed, the extended function processing unit 112 indicates that the verification has not succeeded as a confirmation result. To the control processing communication unit 128.

  In step S507, the extended function processing unit 112 transmits the confirmation result of the server public key certificate of the information provision processing device 150 performed by the user in step S504 to the control processing communication unit 128 of the relay processing device 120 as a verification result. (Step S1122 in FIG. 11).

  In step S508, the control processing communication unit 128 of the relay processing device 120 receives the verification result of the server public key certificate of the information provision processing device 150 by the user terminal 110, and notifies the communication control unit 124 of the result.

  This completes the server certificate verification process.

  Here, the user terminal 110 transmits the verification result of the server public key certificate of the information provision processing device 150 by the user terminal 110 to the relay processing device 120 as a final verification result. The result of the verification process executed by the processing unit 112 may be transmitted to the relay processing device 120 as a final verification result.

(Fig. 6 Details of client authentication process)

  Next, the flow of the client authentication process in the user terminal 110 and the relay processing device 120, which is the details of step S311 in FIG. 3, will be described with reference to FIG.

  Step S601, step S603 to step S605, step S610, step S611, step S613, and step S614 shown in FIG. 6 are executed and implemented by the CPU 201 of the user terminal 110.

  Further, Step S603, Step S606 to Step S612, Step S615, and Step S616 are executed and implemented by the CPU 201 of the relay processing device 120.

  Note that the communication between the user terminal 110 and the relay processing device 120 shown in FIG. 6 uses the control line 162 in FIG.

  In step S601, the extended function processing unit 112 of the user terminal 110 connects to the control processing communication unit 128 of the relay processing device 120 via HTTPS (opens the control line 162), and the information providing processing device together with the server identifier and the client identifier. 150 client authentication condition acquisition request message is transmitted.

  In step S602, the control processing communication unit 128 of the relay processing device 120 matches the key from the proxy communication session management table of the management table storage unit 129 using the server identifier and client identifier received in step S601 as keys. Search for the record you want. Then, the control processing communication unit 128 of the relay processing apparatus 120 acquires a record (proxy communication session record) obtained from the proxy communication session management table of the management table storage unit 129 as a result of the search.

  Then, the control processing communication unit 128 of the relay processing device 120 responds (transmits) the value in the client authentication request field of the acquired proxy communication session record to the extended function processing unit 112 of the user terminal 110 (FIG. 11). Step S1123).

  In step S603, the extended function processing unit 112 of the user terminal 110 analyzes the value of the client authentication request received from the relay processing apparatus 120 in step S601, acquires the signature algorithm and CA identification name that are conditions, A client public key certificate that meets these conditions is acquired from the client public key certificate group stored in the encryption key storage unit 113 (step S1124 in FIG. 11).

  In step S604, the extended function processing unit 112 of the user terminal 110 displays the dialog box including the contents of the client public key certificate acquired in step S603 to the user. Then, the extended function processing unit 112 of the user terminal 110 accepts selection of whether or not the client public key certificate can be used as a certificate used for client authentication to the information provision processing device 150 (step S1124 in FIG. 11). ). If there are a plurality of client public key certificates acquired in step S603, the extended function processing unit 112 displays a dialog box or the like and causes the user to select one as a client public key certificate used for client authentication. After that, a confirmation process is performed (selection of whether or not it can be used is accepted). The extended function processing unit 112 does nothing if there is no client public key certificate that meets the conditions in step S603.

  In step S605, the extended function processing unit 112 of the user terminal 110 transmits the client public key certificate confirmed by the user (selected by the user) in step S604 to the relay processing device 120 (FIG. 11). Step S1125). In addition, if there is no client public key certificate in step S604, the extended function processing unit 112 transmits a message indicating that it is not applicable.

  In step S 606, the control processing communication unit 128 of the relay processing device 120 receives the client public key certificate from the user terminal 110 and passes the client public key certificate to the communication control unit 124. That is, in step S606, the relay processing device 120 acquires a client public key certificate from the user terminal 110 using the control line 162 (acquisition unit).

  In step S607, the communication control unit 124 of the relay processing device 120 stores the client public key certificate in the client certificate column of the proxy communication session record.

  Next, the communication control unit 124 passes the client public key certificate to the server side encryption processing unit 125. In the SSL handshake process with the information provision processing device 150 on the server line 163, the server side encryption processing unit 125 creates an SSL Client Certificate message including the client public key certificate and transmits the SSL Client Certificate message to the information provision processing device 150 ( Step S1126 in FIG. 11 (public key transmission means). If the relay processing apparatus 120 has received a message without a client public key certificate in step S606, the server-side encryption processing unit 125 leaves the certificate area of the SSL Client Certificate message empty, and SSL Client Send a Certificate message.

  In step S608, the control processing communication unit 128 of the relay processing device 120 ends the processing on the relay processing device 120 side when there is no client public key certificate in the SSL Client Certificate message. If there is a client public key certificate in the message, the control processing communication unit 128 of the relay processing device 120 proceeds to step S609.

  In step S609, the communication control unit 124 of the relay processing device 120 creates signature target data based on SSL (including TLS) rules. For example, the data to be signed in TLS / 1.0 is a message from the SSL ClientHello message to the present, as described in “7.4.8. CertificateVerify message” of RFC2246, except for the CertificateVerify message. This is the message digest value of the data obtained by concatenating all received handshake messages. That is, the signature target data is data communicated with the information provision processing device 150 in order to establish encrypted communication of the server line 163. The communication control unit 124 of the relay processing device 120 passes the created signature target data to the control processing communication unit 128.

  In step S610, the extended function processing unit 112 of the user terminal 110 ends the process on the user terminal side when there is no client public key certificate that satisfies the conditions in step S604. If there is a client public key certificate, the extended function processing unit 112 proceeds to step S611.

  In step S611, the extended function processing unit 112 of the user terminal 110 connects to the control processing communication unit 128 of the relay processing device 120 via HTTPS, and transmits a signature target data request message to the relay processing device 120. The extended function processing unit 112 of the user terminal 110 receives the signature target data transmitted by the relay processing apparatus 120 in step S612.

  In step S612, when receiving the signature target data request message from the user terminal 110, the control processing communication unit 128 of the relay processing device 120 receives the signature target data generated in step S609 and the extended function processing unit of the user terminal 110. 112 (step S1127 in FIG. 11).

  In step S613, the extended function processing unit 112 of the user terminal 110 acquires the private key that is paired with the client public key certificate transmitted to the relay processing device 120 in step S605 from the encryption key storage unit 113, and the private key Is used to perform signature processing (encryption) on the signature target data received in step S611 to create signature data.

  In step S614, the extended function processing unit 112 of the user terminal 110 connects to the control processing communication unit 128 of the relay processing device 120 via HTTPS, and transmits the signature data created in step S613 to the relay processing device 120 (FIG. 11). Step S1128).

  In step S615, the control processing communication unit 128 of the relay processing device 120 receives the signature data from the user terminal 110 and passes the signature data to the communication control unit 124.

  In step S616, the communication control unit 124 of the relay processing device 120 passes the signature data to the server-side cryptographic processing unit 125, and the server-side cryptographic processing unit 125 creates an SSL Certificate Verify message including the signature data. The data is transmitted to the provision processing device 150 (step S1129 in FIG. 11) (signature data transmission means).

  This completes the client authentication process.

(Fig. 7 Details of AP data relay processing)

Next, the flow of relay processing of AP (application) data (communication data) in the relay processing device 120, which is the details of step S314 in FIG. 3, will be described with reference to FIG.
Note that steps S701 to S713 illustrated in FIG. 7 are realized by the CPU 201 of the relay processing device 120 executing.

  In step S <b> 701, the client communication unit 121 receives an encrypted communication request message from the user terminal 110 via the proxy line 161 and passes the encrypted communication request message to the client side encryption processing unit 123.

  In step S702, the client side encryption processing unit 123 sends the encrypted communication request message (first encrypted data) to the common key in the proxy communication session record (current processing target record in FIG. 10) in the C column. Decryption is performed using the stored common key (first common key) (first decryption means), and the decrypted plain culture communication request message is created. The client side encryption processing unit 123 passes the plain culture communication request message to the communication control unit 124.

  In step S703, the communication control unit 124 passes the plain culture communication request message (communication data obtained by decrypting the first encrypted data) to the additional function processing unit 130, and the additional function processing unit 130 An additional function (inspection) is executed for the culture communication request message (first inspection means). The additional function processing unit 130 passes, as an execution result (inspection result) of the additional function, a relay propriety determination result indicating whether the relay process can be continued and a relay culture communication request message to the communication control unit 124.

  As an example of the additional function (inspection process), for example, a process for inspecting whether or not data that is prohibited from being transmitted to the outside as confidential information is included by performing keyword inspection on a plain culture communication request message and so on. As a result, if it is determined that the prohibited data is not included in the plaintext communication request message, the relay availability determination result is “Yes”, and the plaintext communication request message for relay is the original plaintext communication request message. It is assumed that the request message is a message with a header “inspected” added. As described above, the additional function processing unit 130 performs an additional function process (inspection process) for inspecting the decrypted data.

  In step S704, the communication control unit 124 proceeds to step S705 if the result of the additional function processing is “possible”, and proceeds to step S713 if the result is “impossible” (first determining means).

  In step S705, the communication control unit 124 passes the relay plaintext communication request message to the server side cryptographic processing unit 125, and the server side cryptographic processing unit 125 passes the relay plaintext communication request message to the proxy communication session record. Is encrypted using the common key stored in the S column and the like, and an encrypted communication request message for relay is created.

  In step S706, the server-side cryptographic processing unit 125 passes the encrypted communication request message for relay to the server communication unit 122, and the server communication unit 122 transmits the encrypted communication request message for relay to the information providing processing device 150. It transmits to the server processing unit 151.

  In step S707, the server communication unit 122 receives the encrypted communication response message (second encrypted data) from the server processing unit 151 of the information provision processing device 150, and sends the encrypted communication response message to the server side. The data is passed to the encryption processing unit 125.

  In step S708, the server-side encryption processing unit 125 decrypts the encrypted communication response message using the common key of the proxy communication session record and the other common key stored in the S column (second common key). (Second decryption means) creates the decrypted plain culture communication response message. The server side encryption processing unit 125 passes the plain culture communication response message to the communication control unit 124.

  In step S709, the communication control unit 124 passes the plain culture communication response message (communication data obtained by decrypting the second encrypted data) to the additional function processing unit 130, and the additional function processing unit 130 An additional function is executed with respect to the Ping culture communication response message (second inspection means). The additional function processing unit 130 passes to the communication control unit 124, as the execution result of the additional function, a relay availability determination result indicating whether the relay process can be continued and a relay plain culture communication response message.

  As an example of the additional function, for example, an anti-virus process is performed on the Heibun communication response message. In this case, the additional function processing unit 130 checks whether or not a virus is included in the plaintext communication response message, and if it is determined that a virus is included in the plaintext communication response message, the relay possibility determination is performed. The result is “impossible”. In this case, the relay processing device 120 does not send the relay plain communication response message to the user terminal 110, but sends a message such as “The communication line has been cut off because a virus is detected” to the user terminal 110. It is expected to send.

  In other words, the relay processing apparatus 120 does not transmit the plain culture communication response message to the user terminal 110 when the relay enable / disable determination result is “impossible” as an execution result of the additional function by the additional function processing unit 130. If the relay availability determination result is “OK”, it is determined to relay the PyeongChang communication response message to the user terminal 110 (second determination means).

  If the relay result determination result is “possible” as an inspection result by the additional function processing unit 130 (for example, when it is determined that a virus is not included in the Ping culture communication response message), in step S710, the communication control unit 124 The relay side communication response message is passed to the client side encryption processing unit 123, and the client side encryption processing unit 123 stores the relay side communication communication response message in the common key of the proxy communication session record, etc. The encrypted common response key is used to generate an encrypted communication response message for relay.

  In step S711, the client side encryption processing unit 123 passes the encrypted communication response message for relay to the client communication unit 121, and the client communication unit 121 sends the encrypted communication response message for relay to the user terminal 110. It transmits to the browsing processing part 111.

  In step S712, the communication control unit 124 determines whether to end application communication (HTTP transaction) from the plain culture communication response message or the like. If it determines with continuing, it will progress to step S701.

  In step S713, the communication control unit 124 determines that “request transmission is prohibited based on the relay availability determination result (relay availability determination result is“ impossible ”) generated in step S703 and the plain culture communication request message for relay. And so forth, and the process proceeds to step S710. In step S710, the relay processing device 120 encrypts the generated relay communication response message for relay using the common key of the proxy communication session record and the common key stored in the column C, and An encrypted communication response message for relay is created and transmitted to the user terminal 110 in step S711.

  This is the end of the AP data relay process.

  As described above, according to the present embodiment, when data by encrypted communication is relayed, the data can be inspected, and the authenticity of the communication partner can be confirmed based on the authentic certificate.

  Furthermore, according to the present embodiment, for example, when a Web page such as a bank deposit is viewed on a user terminal, personal information such as a password of an operation user of the user terminal is also checked by the relay processing device. Is reduced.

That is, since it is possible to determine whether or not to check the data to be communicated according to the website, it is possible to improve security such as information leakage and to control not to acquire and check personal information. Is possible.

  Moreover, according to this embodiment, the information provision processing apparatus can confirm the authenticity of the user terminal that is the communication partner.

  Further, according to the present invention, when the encrypted communication by the proxy method is resumed, it can be resumed by using the session ID and the common key that are already stored.

  Although the embodiments have been described in detail above, the present invention can take an embodiment as, for example, a system, an apparatus, a method, a program, or a storage medium, and specifically includes a plurality of devices. The present invention may be applied to a system that is configured, or may be applied to an apparatus that includes a single device.

<Second Embodiment>
In the first embodiment, in HTTPS (HTTP over SSL (including TLS)) communication, the user terminal 110 connects to the relay processing device 120 (proxy server) by the CONNECT method, and then to the information provision processing device 150 (Web server). The method of decrypting encrypted communication information and executing an additional function and the method of effectively functioning entity authentication even in such a case have been described for the mechanism for tunneling communication. However, since the relay protocol by the CONNECT method is a general-purpose transport communication tunneling method that is not limited to HTTP communication, for example, IMAP over SSL (including TLS), POP3 over SSL (including TLS), SMTP over SSL (TLS) Even in the case of other communication protocols using SSL (including TLS) such as

  For example, when applied to IMAP over SSL (including TLS), the browsing processing unit 111 of the user terminal 110 is a mail user agent having an IMAP over SSL (including TLS) client function, and the information provision processing device 150. The server processing unit 151 is an IMAP server having an IMAP over SSL (including TLS) function.

As described above, according to this embodiment, when relaying data by encrypted communication without changing each communication protocol, the data can be inspected and communication is performed based on a genuine certificate. The authenticity of the other party can be confirmed.

Further, since the control line is also SSL communication, spoofing of the relay processing device itself can be prevented. Next, functions of the relay processing apparatus according to the present invention will be described with reference to FIGS. 19 and 20.

  FIG. 19 is a functional block diagram of the relay processing apparatus according to the present invention. Reference numeral 1901 denotes a relay processing apparatus according to the present invention.

That is, 1901 is a relay processing device 120 that relays communication data communicated between the client terminal (user terminal 110) and the information processing device (information providing processing device 150).

Here, the user terminal 110 of this embodiment is an application example of the client terminal of the present invention. Also, the information provision processing device 150 of this embodiment is an application example of the information processing device of the present invention. Reference numeral 1902 denotes a first establishment unit that establishes first SSL communication used for communication data communication with the client terminal. Reference numeral 1903 denotes a second establishment unit that establishes second SSL communication used for communication of communication data with the information processing apparatus.

1904 is a client that establishes the first SSL communication by the first establishing unit, and the public key certificate of the information processing device acquired from the information processing device when the second establishing unit establishes the second SSL communication. It is a transmission part which transmits to a terminal.

  Next, functions of the relay processing apparatus according to the present invention will be described with reference to FIG.

  FIG. 20 is a functional block diagram of the relay processing apparatus according to the present invention.

A relay processing device 120 relays communication data communicated between the client terminal (user terminal 110) and the information processing device (information providing processing device 150).

  Reference numerals 1902, 1903, and 1904 are the same as those described with reference to FIG. Reference numeral 2001 denotes a communication establishment unit that establishes control communication with a client terminal.

In addition, the transmission unit 1904 uses the public key certificate of the information processing device acquired from the information processing device when the second establishment unit establishes the second SSL communication, using the control communication established by the communication establishment unit. Then, the first establishment unit transmits it to the client terminal that establishes the first SSL communication.

  A receiving unit 2002 receives a request for SSL communication from the client terminal to the information processing apparatus.

In 2003, the first establishing unit establishes the first SSL communication and the second establishing unit establishes the second SSL communication on the condition that the receiving unit receives the SSL communication request from the client terminal. It is a control part which controls to.

Reference numeral 2004 denotes a relay unit that relays communication data communicated between the client terminal and the information processing apparatus using third SSL communication established between the client terminal and the information processing apparatus.

2005 is a communication method for permitting relaying of communication data for relay destination information indicating an information processing apparatus that is a relay destination of communication data transmitted from a client terminal. A proxy communication method for relaying communication data using a direct communication method for relaying data or a first SSL communication established by a first establishment unit and a second SSL communication established by a second establishment unit It is a storage unit for storing communication method setting information in which communication method information indicating the above is set.

  Reference numeral 2006 denotes a reception unit that receives relay destination information for relaying communication data from a client terminal.

In 2007, between the communication method setting information stored in the storage unit and the relay destination information received by the reception unit, between the information processing apparatus and the client terminal of the relay destination indicated by the relay destination information received by the reception unit. It is a communication determination part which determines whether the communication system which permits communication of this is a direct communication system, or a proxy communication system.

Here, the control unit 2003 uses the first determination unit to set the first communication unit on the condition that the proxy determination method is determined as the communication method for permitting communication between the information processing apparatus and the client terminal. Control to establish the second SSL communication by the second establishing unit.

In addition, the relay unit 2004 further includes the client terminal and the information processing apparatus on the condition that the communication determining unit determines that the direct communication method is determined as a communication method for permitting communication between the information processing device and the client terminal. Communication data communicated between the client terminal and the information processing apparatus is relayed using the third SSL communication established between the client terminal and the information processing apparatus.

Further, in the communication method setting information stored in the storage unit, client information indicating a client terminal is further set with respect to the relay destination information, and the reception unit is a client of the client terminal that has received the relay destination information. The communication determination unit further receives information, and the communication determination unit receives the relay destination information received by the reception unit according to the communication method setting information stored in the storage unit, the relay destination information received by the reception unit, and the client information received by the reception unit. The communication method for permitting communication between the information processing apparatus of the relay destination shown in FIG. 5 and the client terminal indicated by the client information received by the receiving unit is determined.

The communication method information of the communication method setting information stored in the storage unit further includes instruction information indicating that a communication method for performing communication is determined according to an instruction from the user operating the client terminal.

In 2008, when the communication method information of the communication method setting information stored in the storage unit with respect to the relay destination information received by the receiving unit is the instruction information, an instruction screen for receiving a communication method instruction is displayed on the client terminal. It is a communication system transmission part which transmits the communication system instruction information for displaying to a client terminal.

2009 is a communication method reception for receiving, from the client terminal, communication method information indicating a communication method instructed by an operation user of the client terminal via an instruction screen displayed according to the communication method instruction information transmitted by the communication method transmitting unit. Part.

  Further, the communication determining unit further determines the communication method indicated by the communication method information received by the communication method receiving unit between the information processing apparatus at the relay destination indicated by the relay destination information received by the receiving unit and the client terminal. The communication unit determines the communication method for performing communication, and the control unit further sets the first condition on the condition that the communication determining unit determines the proxy communication method as the communication method for performing communication between the information processing apparatus and the client terminal. Control is performed so that the establishment unit establishes the first SSL communication and the second establishment unit establishes the second SSL communication.

  In the communication method setting information stored in the storage unit, client information indicating the client terminal is further set with respect to the relay destination information, and the reception unit receives the client information of the client terminal that has received the relay destination information. The communication method transmission unit instructs the communication method when the communication method information of the communication method setting information stored in the storage unit for the relay destination information and the client information received by the reception unit is the instruction information. The communication method instruction information for displaying the instruction screen for the client terminal is transmitted to the client terminal.

  2010 is an acquisition unit that acquires the public key certificate of the client terminal from the client terminal using the control communication established by the communication establishment unit.

2011, a public key certificate of the client terminal acquired by the acquiring unit is transmitted to the information processing device as a public key certificate of the relay processing device used when the second establishing unit establishes the second SSL communication. It is a key transmission unit.

2012 is a secret key corresponding to the public key certificate of the client terminal in which the data communicated with the information processing device to establish the second SSL communication by the second establishing unit is transmitted to the information processing device by the public key transmitting unit. This is a signature data transmission unit that transmits signature data generated by being encrypted to the information processing apparatus.

2013 is the first SSL communication in which the first establishment unit receives the first encrypted data obtained by encrypting the communication data received from the client terminal using the first SSL communication established by the first establishment unit. It is the 1st decoding part which decodes using the 1st common key produced | generated when establishing.

  Reference numeral 2014 denotes a first inspection unit that inspects communication data obtained by decrypting the first encrypted data by the first decryption unit.

  Reference numeral 2015 denotes a first determination unit that determines whether or not to relay the communication data inspected by the first inspection unit to the information processing device according to the inspection result by the first inspection unit.

In 2016, the second encrypted data obtained by encrypting the communication data received from the information processing apparatus using the second SSL communication established by the second establishing unit is sent to the second SSL by the second establishing unit. The second decryption unit decrypts the second common key generated when establishing communication.

  Reference numeral 2017 denotes a second inspection unit that inspects communication data obtained by decrypting the second encrypted data by the second decryption unit.

  2018 is a 2nd determination part which determines whether the communication data test | inspected by the 2nd test | inspection part are relayed to a client terminal according to the test result by a 2nd test | inspection part.

2019 includes a first common key generated when the first establishing unit establishes the first SSL communication, first session identification information for identifying the session of the first SSL communication, and a second establishing unit The proxy communication storage unit stores the second common key generated when the second SSL communication is established in association with the second session identification information for identifying the second SSL communication session.

  2020 is a restart request receiving unit that receives an SSL communication restart request including the first session identification information from the client terminal to the information processing apparatus.

2021 is a determination unit that determines whether the first session identification information included in the SSL communication restart request received by the restart request reception unit is stored in the proxy communication storage unit.

When the determination unit 2022 determines that the first session identification information is stored in the proxy communication storage unit, 2021 is stored in the proxy communication storage unit in association with the first session identification information. The second common key and the second session identification stored in the proxy communication storage unit in association with the first session identification information are resumed with the client terminal using the common key. A communication resuming unit that resumes the second SSL communication with the information processing apparatus using the information.

  Note that the control communication established by the communication establishment unit 2001 is SSL communication.

Although one embodiment of the present invention has been described in detail above, the present invention can take an embodiment as, for example, a system, apparatus, method, program executable by the apparatus, or a storage medium. In addition, the present invention may be applied to a system composed of a plurality of devices, or may be applied to an apparatus composed of a single device.

Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (basic system or operating system) running on the computer based on the instruction of the program code. Needless to say, a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function is determined based on the instruction of the program code. It goes without saying that the CPU or the like provided in the expansion board or function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

110 User terminal 111 Browsing processing unit 112 Extended function processing unit 113 Encryption key storage unit 114 Management table storage unit 115 CA certificate storage unit 120 Relay station processing device 121 Client communication unit 122 Server communication unit 123 Client side cryptographic processing unit 124 Proxy Communication control unit 125 Server side encryption processing unit 126 Proxy encryption key storage unit 127 Server encryption key storage unit 128 Control processing communication unit 129 Management table storage unit 130 Additional function processing unit 131 CA certificate storage unit 150 Information provision processing device 151 Server Processing unit 152 Server encryption key storage unit 161 Proxy line 162 Control line 163 Server line

Claims (9)

A relay processing device that relays communication data communicated between a client terminal and an information processing device,
In order to relay the communication data communicated between the client terminal and the information processing apparatus, a first SSL communication used for communication of the communication data between the relay processing apparatus and the client terminal is established. First establishing means;
In order to relay the communication data communicated between the client terminal and the information processing device, a second SSL communication used for communication of the communication data between the relay processing device and the information processing device is established. A second establishing means to:
Communication establishment means for establishing control communication between the relay processing device and the client terminal separately from the first SSL communication;
Using the control communication established by the communication establishment means, the public key certificate of the information processing apparatus acquired from the information processing apparatus when establishing the second SSL communication by the second establishment means, A transmission means for transmitting to the client terminal;
Obtaining means for obtaining a public key certificate of the client terminal from the client terminal using control communication established by the communication establishing means;
The client terminal public key certificate acquired by the acquiring unit is transmitted to the information processing apparatus as the public key certificate of the relay processing apparatus used when the second establishing unit establishes the second SSL communication. Public key transmission means;
A relay processing apparatus comprising: Receiving means for receiving a request for SSL communication from the client terminal to the information processing apparatus;
The first establishing means establishes the first SSL communication and the second establishing means establishes the second SSL communication on condition that the receiving means receives the SSL communication request from the client terminal. Control means for controlling
The relay processing apparatus according to claim 1, further comprising: Data communicated with the information processing apparatus to establish the second SSL communication by the second establishing means corresponds to the public key certificate of the client terminal transmitted to the information processing apparatus by the public key transmitting means. relay processing apparatus according to claim 1 or 2, further comprising a signature data transmission means for transmitting the signature data generated by being encrypted to the information processing apparatus using a private key. A first common key generated when the first establishing means establishes the first SSL communication, first session identification information for identifying a session of the first SSL communication, and the second establishing means. Proxy communication storage means for storing the second common key generated when establishing the second SSL communication and second session identification information for identifying the second SSL communication session in association with each other,
Resumption request receiving means for receiving a resumption request for SSL communication including the first session identification information from the client terminal to the information processing apparatus;
A determination unit that determines whether the first session identification information included in the SSL communication restart request received by the restart request reception unit is stored in the proxy communication storage unit;
When it is determined by the determination means that the first session identification information is stored in the proxy communication storage means, the first session identification information is stored in the proxy communication storage means in association with the first session identification information. Resuming the first SSL communication with the client terminal using the first common key, and storing the second common in association with the first session identification information and stored in the proxy communication storage means Communication resuming means for resuming the second SSL communication with the information processing apparatus using the key and the second session identification information;
Relay processing apparatus according to any one of claims 1 to 3, further comprising a. The first encrypted data obtained by encrypting the communication data received from the client terminal using the first SSL communication established by the first establishing means is transmitted to the first establishing means by the first establishing means. First decryption means for decrypting using the first common key generated when establishing SSL communication;
First inspection means for inspecting communication data obtained by decrypting the first encrypted data by the first decryption means;
First determining means for determining whether to relay the communication data inspected by the first inspecting means to the information processing device according to the inspection result by the first inspecting means;
Further comprising a relay processing unit according to any one of claims 1 to 4, characterized in. Second encrypted data obtained by encrypting the communication data received from the information processing apparatus using the second SSL communication established by the second establishing means is transmitted to the second established means by the second establishing means. Second decryption means for decrypting using the second common key generated when establishing the SSL communication;
Second inspection means for inspecting communication data obtained by decrypting the second encrypted data by the two decryption means;
Second determining means for determining whether to relay the communication data inspected by the second inspecting means to the client terminal according to the inspection result by the second inspecting means;
Relay processing apparatus according to any one of claims 1 to 5, further comprising a. It said control communication being established in the communication establishing means includes relay processing apparatus according to any one of claims 1 to 6, characterized in that a SSL communication. A relay processing method of a relay processing device that relays communication data communicated between a client terminal and an information processing device,
Communication of the communication data between the relay processing device and the client terminal so that the first establishing means of the relay processing device relays the communication data communicated between the client terminal and the information processing device A first establishing step of establishing a first SSL communication used in
The communication data between the relay processing device and the information processing device in order for the second establishing means of the relay processing device to relay the communication data communicated between the client terminal and the information processing device. A second establishing step of establishing a second SSL communication used in the communication of
A communication establishment step in which the communication establishment means of the relay processing device establishes control communication between the relay processing device and the client terminal separately from the first SSL communication;
The transmission means of the relay processing device establishes the public key certificate of the information processing device acquired from the information processing device when the second SSL communication is established in the second establishment step by the communication establishment step. using a control communication, a transmission step of transmitting to said client terminal,
The acquisition unit of the relay processing device acquires the public key certificate of the client terminal from the client terminal using the control communication established in the communication establishment step;
The public key transmitting means of the relay processing device uses the public key certificate of the client terminal acquired in the acquiring step to disclose the relay processing device used when establishing the second SSL communication in the second establishing step. A public key transmitting step for transmitting to the information processing apparatus as a key certificate;
A relay processing method for a relay processing apparatus, comprising: A program that can be read and executed by a relay processing device that relays communication data communicated between a client terminal and an information processing device,
The relay processing device;
In order to relay the communication data communicated between the client terminal and the information processing apparatus, a first SSL communication used for communication of the communication data between the relay processing apparatus and the client terminal is established. First establishing means;
In order to relay the communication data communicated between the client terminal and the information processing device, a second SSL communication used for communication of the communication data between the relay processing device and the information processing device is established. A second establishing means to:
Communication establishment means for establishing control communication between the relay processing device and the client terminal separately from the first SSL communication;
Using the control communication established by the communication establishment means, the public key certificate of the information processing apparatus acquired from the information processing apparatus when establishing the second SSL communication by the second establishment means, A transmission means for transmitting to the client terminal ;
Obtaining means for obtaining a public key certificate of the client terminal from the client terminal using control communication established by the communication establishing means;
The client terminal public key certificate acquired by the acquiring unit is transmitted to the information processing apparatus as the public key certificate of the relay processing apparatus used when the second establishing unit establishes the second SSL communication. program for causing to function as a public key transmission unit.

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