JP2019004289A - Information processing apparatus, control method of the same, and information processing system - Google Patents

Abstract

To issue client certificates to devices more properly.SOLUTION: The information processing apparatus that operates as a certificate authority that issues a certificate to a device, and includes: existence confirmation means that connects to the device and checks existence of the device; authorization confirmation means for referring to given access authority information to confirm access authority regarding a given service of the device; and issuing means for issuing a client certificate to the device on the basis of the confirmation result by the existence confirmation means and the confirmation result by the authority confirmation means.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an information processing apparatus that operates as a certificate authority that issues a public key certificate, a control method thereof, and a system.

  A public key certificate is used to prevent spoofing of a communication partner in TLS (Transport Layer Security) that is a protocol for encrypting a communication path of an IP network. For example, it is possible to authenticate that the Web server is a valid communication partner by verifying the public key certificate (server certificate) transmitted from the Web server by the Web browser.

  A server certificate, which is a public key certificate used for server authentication, is issued according to the following procedure. First, a certificate signing request including the public key of the server is generated on the server and transmitted to the certificate authority. Next, after confirming the existence of the server, the certificate authority signs the server's public key using the certificate authority's private key, and generates a public key certificate in a predetermined format.

  Non-Patent Document 1 proposes an ACME protocol for the purpose of issuing server certificates and automating settings. In the ACME protocol, a certificate authority accesses a server and confirms its existence, thereby automating a series of processes from generation of a certificate signature request to issuance of a public key certificate.

Automatic Certificate Management Environment (ACME), draft-ietf-acme-acme-03, https://datatracker.ietf.org/doc/draft-ietf-acme-acme/, 2016

  However, in the above-mentioned ACME protocol, there is no provision for an appropriate rule for issuing a client certificate for a device having both a TLS server function and a TLS client function. Therefore, when issuing a client certificate in the same manner as issuing a server certificate, the issued client certificate merely proves that the device has a host name appropriately set. In other words, it cannot be proved that the user has authority to access the service.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a mechanism that can more appropriately execute issuance of a client certificate to a device.

  In order to solve the above-described problems, an information processing apparatus according to the present invention has the following configuration. That is, an information processing apparatus that operates as a certificate authority that issues a certificate to a device is connected to the device to check presence of the device, and refers to the given access authority information to the device. Authority confirming means for confirming the access authority for the given service; first issuing means for issuing a client certificate to the device based on the confirmation result by the existence confirming means and the confirmation result by the authority confirming means; Have.

  According to the present invention, it is possible to provide a mechanism that can more appropriately issue a client certificate to a device.

It is the block diagram which showed the component of the information processing system which concerns on 1st Embodiment. It is a figure which shows an example device / service correspondence table | surface. It is a sequence diagram which shows the issuing operation | movement of the client certificate in 1st Embodiment. It is a sequence diagram which shows the issuing operation | movement of the client certificate in 2nd Embodiment. It is a figure which shows the hardware constitutions of information processing apparatus.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. The following embodiments are merely examples, and are not intended to limit the scope of the present invention.

(First embodiment)
As a first embodiment of the information processing apparatus according to the present invention, a certificate authority (ACME server) that confirms the existence of a device (device) according to the ACME protocol will be described below as an example. ACME is an abbreviation for Automatic Certificate Management Environment.

<System configuration>
FIG. 1 is a block diagram illustrating components of the information processing system according to the first embodiment. The information processing system includes a device 100 on which a public key certificate (client certificate or the like) is installed, and a certificate authority 200 that issues the public key certificate. The device 100 and the certificate authority 200 are connected so as to be communicable via an arbitrary communication path.

  The device 100 includes functional units of an HTTP server 101, a TLS server 102, an HTTP client 103, and a TLS client 104. In other words, the device 100 has a function of accessing other devices via the HTTP protocol and a function of accepting access from other devices. In addition, TLS can be used for the access. The device 100 further includes an account public key 106 and an account secret key 107 that are used in the ACME protocol process. In addition, the structure which accesses the storage medium (an optical disc, a semiconductor storage medium, etc.) which stored the account public key 106 and the account private key 107 may be sufficient.

  The certificate authority 200 has functional units of an HTTP server 201, a TLS server 202, an HTTP client 203, and a TLS client 204. In other words, the certificate authority 200 also has a function of accessing other devices via the HTTP protocol and a function of accepting access from other devices. In addition, TLS can be used for the access. The certificate authority 200 further includes a device / service correspondence table 205. Details of the device / service correspondence table 205 will be described later.

  FIG. 5 is a diagram illustrating a hardware configuration of an information processing apparatus 500 that configures each apparatus (device 100 and certificate authority 200) of the information processing system. Here, as an example, a configuration similar to that of a generally popular PC is shown. When the information processing apparatus 500 executes a predetermined software program, each function in the device 100 and the certificate authority 200 is realized.

  Inside the information processing apparatus 500, blocks which will be described later are connected by a bus 510, and various data can be transferred. The MPU 501 can control the operation of each block in the information processing apparatus 500 or can execute a program stored in the HDD 503 or the ROM 504. The main storage device 502 is a device that temporarily stores programs and data to be processed for processing performed in the MPU 501.

  An input interface (I / F) 507 inputs information input from a user via the keyboard 505 or the mouse 506 to the information processing apparatus 500. The display 508 displays an operation screen for the user. A network interface (I / F) 509 is used for communication with other devices. In addition, you may comprise so that the input from the above-mentioned user and the display of an operation screen may be performed with an external apparatus via network I / F509.

<Device / service compatibility table>
FIG. 2 is a diagram exemplarily showing the device / service correspondence table 205. The device / service correspondence table 205 is a table including a record in which three pieces of information of “device ID”, “URI”, and “connection availability” are associated. However, it may be configured as given access authority information in another format without being configured in a table format.

  The “device ID” field is a field for storing device identification information (identifier) as a value. For example, the serial number of the device is stored. The “URI” field is a field for storing information indicating an access destination for accessing a given service as a value. Here, a URI (Uniform Resource Identifier) corresponding to the service is stored. The “connectability” field is a field that stores, as a value, information indicating whether the device specified in the “device ID” field can access the service identified in the “URI” field. For example, a value of “permitted” is entered when access is possible, and “not permitted” is entered when access is not possible.

  FIG. 2 shows, as an example, a table indicating whether or not each apparatus provided by the server “Example.com” can be accessed with respect to a device whose device ID is “AAA”. Here, an example is shown in which access to the browse service is permitted, but access to the upload service is not permitted.

  The device / service correspondence table 205 may be manually input by an administrator via a management UI that is one of operation screens, or may be automatically generated at least partially. For example, the device ID may be automatically generated using a network identifier such as a device MAC address. Further, communication with a service providing server having a predetermined URI may be performed to determine whether or not the device can be connected.

<System operation>
FIG. 3 is a sequence diagram showing a client certificate issuance operation in the first embodiment. In the first embodiment, there are four phases: “Preliminary preparation (S301 to S303)”, “Existence confirmation (S304 to S310)”, “Server certificate issuance (S311 to S315)”, and “Client certificate issuance (S316 to S325)”. Consists of

  In step S301, the device 100 generates a pair of the account public key 106 and the account secret key 107. In step S <b> 302, the device 100 transmits the account public key 106 to the certificate authority 200. In step S303, the certificate authority 200 registers the received account public key 106. As a result, the device 100 completes registration with the certificate authority 200, which is an ACME server, as an ACME client.

  In step S304, the device 100 transmits the host name as an identifier to the certificate authority 200. In step S305, the certificate authority 200 transmits a challenge to the device 100. The challenge here is a random number called token. In step S <b> 306, the device 100 transmits a response that is a value obtained by converting token with the account secret key 107 to the certificate authority 200. In addition, the device 100 configures the URI to be accessed by the certificate authority 200 as “http: // {domain} /.well-known/acme- challenge / {token}”, and makes the certificate authority 200 accessible.

  In step S307, the certificate authority 200 accesses “http: // {domain} /.well-known/acme-charge/ {token}”. In step S308, the device 100 transmits a response to access. In step S309, the certificate authority 200 confirms that the result of converting the response with the account public key 106 is equal to token. In step S310, the device 100 polls the certificate authority 200 to notify that the authentication is complete. As a result, the certificate authority 200 can confirm that the device 100 exists by communication conforming to the ACME protocol.

  In step S311, the device 100 generates a secret key and a public key to be used in S312 to S315. In step S312, the device 100 generates a certificate signing request (CSR). Specifically, a server certificate signature request is generated based on the host name, validity period, and the like. In step S313, the device 100 adds a signature to the server certificate signature request with the account private key and transmits the request to the certificate authority 200.

  In step S314, the certificate authority 200 verifies the signed server certificate signing request using the account public key, and generates a server certificate if the verification is successful. In step S315, the certificate authority 200 transmits the server certificate and the update URI to the device 100.

  In step S316, the device 100 generates a secret key and a public key to be used in S317 to S325. In step S317, the device 100 generates a certificate signature request (CSR). Specifically, the client certificate signature request is generated based on the device ID, the validity period, and the like. In step S318, the device 100 adds a signature to the client certificate signature request with the account private key and transmits the request to the certificate authority 200.

  In step S319, the certificate authority 200 verifies the signature with the account public key. If the verification fails (NO in S319), the process ends without issuing a client certificate. If the verification is successful (YES in S319), the process proceeds to S320.

  In step S320, the certificate authority 200 compares the public key included in the certificate signature request received in S313 with the public key included in the certificate signature request received in S318. If it is determined that they are the same (NO in S320), the client certificate is suppressed and the process is terminated. If not the same (YES in S320), the process proceeds to S321.

  In step S321, the certificate authority 200 confirms whether or not the usage included in the certificate signature request received in S318 is a predetermined usage that is appropriate as a client certificate. Here, the values of “Key Usage” and “Extended Key Usage” are confirmed. Specifically, it is confirmed whether the value of “Key usage” is “Digital signature” and the value of “Extended key usage” is “TLS Web client”. If it is appropriate (YES in S321), the process proceeds to S322. If it is not appropriate (NO in S321), the client certificate is suppressed and the process is terminated.

  In step S322, the certificate authority 200 has the “Subject” field in the certificate signature request equal to the “Device ID” item in the device / service correspondence table 205, and the “Connectability” item is “Allowed”. Confirm (permission confirmation). If there is no device ID corresponding to the device / service correspondence table 205 (NO in step S322), the client certificate is suppressed and the process is terminated. If it exists (YES in step S322), the process proceeds to S323.

  In step S323, the certificate authority 200 generates a client certificate. In step S324, the certificate authority 200 transmits the client certificate and the update URI to the device 100. In step S325, the certificate authority 200 transmits the issued client certificate to the service providing server of the URI item of the device / service correspondence table 205 to register it.

  The processing related to server certificate issuance (S311 to S315) may be omitted. In that case, S320 is also unnecessary. Further, the public key / private key generation in S316 may be changed to be performed when the power is turned on.

  As described above, according to the first embodiment, the client certificate for the device is issued based on the confirmation result of the presence of the device and the confirmation result of the authority to access the service of the device. This makes it possible to appropriately issue a client certificate corresponding to the access authority to the service.

  In the first embodiment, after the certificate authority confirms the existence of the device in accordance with the ACME protocol, the client certificate CSR is transmitted from the device to the certificate authority. The certificate authority issues a client certificate after confirming whether the device can be connected. Therefore, this form is suitable for a use case of acquiring a client certificate at the same time when the server certificate is frequently updated using ACME.

(Second Embodiment)
In the second embodiment, a mode is described in which a certificate authority obtains a certificate signature request (CSR) from the device 100 using a TLS communication path and issues a client certificate in order to execute server authentication. This form can be suitably implemented when a TLS client and a TLS server are always operating like a network monitoring server.

<System operation>
FIG. 4 is a sequence diagram illustrating a client certificate issuance operation according to the second embodiment. The second embodiment includes two phases: “TLS communication path establishment (S401 to S406)” and “client certificate issuance (S408 to S416)”.

  In step S401, the device 100 transmits a connection request as an HTTP client to the certificate authority 200. In step S402, the certificate authority 200 starts a TLS establishment procedure with the device 100. That is, a “ClientHello” message is transmitted to the device 100. In step S403, the device 100 transmits a “ServerHello” message, a server certificate, and a “ServerHelloDone” message.

  In step S404, the certificate authority 200 verifies the digital signature of the server certificate. If the digital signature verification is successful, the process proceeds to S405. In step S405, the certificate authority 200 encrypts the PreMasterSecret used for generating the encryption key with the public key of the server certificate. The encrypted PreMasterSecret is transmitted with a “ClientKeyExchange” message. Further, a “Change Cipher Spec” and “Finished” message are transmitted. In step S406, the device 100 transmits a “Change Cipher Spec” and “Finished” message.

  When the above TLS establishment procedure is completed, a TLS communication path is established between the device 100 and the certificate authority 200, and data can be encrypted and transmitted / received. Further, the certificate authority 200 can confirm the existence of the device 100 by the TLS establishment procedure.

  In the above description, the message transmitted and received at the time of establishing the TLS connection has been described using the server certificate, and the cipher suite for exchanging keys using the public key of the server certificate. However, server authentication is performed. Other cipher suites may be used. For example, a cipher suite using an ECDH (Elliptic curve Diffie-Hellman) key exchange method can be used. However, in this case, the message to be transmitted / received is partially different from the above description.

  The client certificate issuance (S408 to S416) corresponds to S316 to S325 of the first embodiment. However, as described above, the existence confirmation of the device 100 by the certificate authority 200 is completed by the server certificate verification process (S404). Therefore, the certificate authority 200 does not need to verify the signature with the account public key (S319).

  As described above, according to the second embodiment, the certificate authority 200 establishes a TLS communication path, causes the device 100 to transmit a certificate signature request, and issues a client certificate. In other words, by confirming the presence of the device 100 upon completion of the TLS establishment procedure, simpler processing can be achieved.

(Other examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  100 equipment; 101 HTTP server; 102 TLS server; 103 HTTP client; 104 TLS client; 106 account public key; 107 account secret key; 200 certificate authority; 201 HTTP server; 202 TLS server; 203 HTTP client; Device / service compatibility table

Claims (10)

An information processing apparatus that operates as a certificate authority that issues a certificate to a device,
A presence checking means for connecting to a device and checking the presence of the device;
Authority confirmation means for confirming access authority regarding a given service of the device with reference to given access authority information;
First issuing means for issuing a client certificate to the device based on the confirmation result by the presence confirmation means and the confirmation result by the authority confirmation means;
An information processing apparatus comprising: The information processing apparatus according to claim 1, wherein the presence confirmation unit performs the presence confirmation through communication based on an ACME (Automatic Certificate Management Environment) protocol. Second issuing means for issuing a server certificate to the device;
Comparison comparing the second public key included in the certificate signing request for the server certificate received from the device and the first public key included in the certificate signing request for the client certificate received from the device Means,
Further comprising
The first issuing unit suppresses the issuance of the client certificate when the comparing unit determines that the first public key and the second public key are the same. The information processing apparatus according to claim 1 or 2. The information processing apparatus according to claim 1, wherein the presence check unit executes the presence check by establishing a TLS communication path with the device. The information processing apparatus according to claim 4, wherein the presence check unit performs the presence check by verifying a server certificate received from the device when the TLS communication path is established. Further comprising confirmation means for confirming whether or not the usage of the first public key included in the certificate signature request of the client certificate received from the device is a predetermined usage;
The said 1st issuing means suppresses issuing of the said client certificate, when it is confirmed by the said confirmation means that the use use of the said 1st public key is not the said predetermined use. The information processing apparatus according to any one of 1 to 5. The given access authority information is configured as a table including a record in which a device identifier, a URI (Uniform Resource Identifier) indicating a service, and information indicating whether the device can access the service are associated with each other. The information processing apparatus according to any one of claims 1 to 6. A method of controlling an information processing apparatus that operates as a certificate authority that issues a certificate to a device,
A presence confirmation step of connecting to a device and confirming the presence of the device;
An authority confirmation step for confirming access authority for a given service of the device with reference to given access authority information;
Issuing step of issuing a client certificate to the device based on the confirmation result in the presence confirmation step and the confirmation result in the authority confirmation step;
A method for controlling an information processing apparatus, comprising:   The program for functioning a computer as each means of the information processing apparatus of any one of Claims 1 thru | or 7. An information processing system including a device and a certificate authority that issues a certificate to the device,
The certificate authority
Presence checking means for connecting to the device and checking the presence of the device;
Authority confirmation means for confirming access authority regarding a given service of the device with reference to given access authority information;
Issuing means for issuing a client certificate to the device based on the confirmation result by the existence confirmation unit and the confirmation result by the authority confirmation unit;
An information processing system comprising:

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