CN105376346A - Method and system for improving safety of dynamic host configuration protocol (DHCP) - Google Patents
Method and system for improving safety of dynamic host configuration protocol (DHCP) Download PDFInfo
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- CN105376346A CN105376346A CN201510900317.5A CN201510900317A CN105376346A CN 105376346 A CN105376346 A CN 105376346A CN 201510900317 A CN201510900317 A CN 201510900317A CN 105376346 A CN105376346 A CN 105376346A
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- dhcp
- dynamic host
- host configuration
- configuration protocol
- protocol server
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L61/00—Network arrangements, protocols or services for addressing or naming
- H04L61/50—Address allocation
- H04L61/5007—Internet protocol [IP] addresses
- H04L61/5014—Internet protocol [IP] addresses using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
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Abstract
The invention relates to a method and system for improving safety of a dynamic host configuration protocol (DHCP). A DHCP client side firstly initiates a DHCP request, and sends a DHCP-DISCOVER broadcast message without any sensitive information; a DHCP server responds to the request of the client side; and the DHCP client side receives a response message of the server, then extracts a source media access control (MAC) address in the response message, reconstructs a DHCP-DISCOVER unicast message, adds any required DHCP options in the unicast message according to the definition of the DHCP so as to construct a new message, and sends the new message out. According to the method and system for improving safety of the DHCP, the DHCP-DISCOVER unicast message is reconstructed, and the sensitive information is uploaded, so that the problem of information leakage in uploading of the sensitive information by the DHCP client side is solved.
Description
Technical field
The present invention relates to communication technical field, is a kind of method and system improving DHCP protocol safety specifically.
Background technology
Specific definition DHCP agreement (DynamicHostConfigurationProtocol in RFC2131, DHCP), DHCP agreement adopts customer end/server mode, provides a kind of mechanism for client dynamic IP address allocation and network configuration thereof.
The classical group net mode of DHCP protocol system is shown in Fig. 1 and Fig. 2.
Only have a network segment in Fig. 1, Dynamic Host Configuration Protocol server can directly receive the broadcasting packet sent from dhcp client.
Multiple network segment is had in Fig. 2, route conversion is carried out by access device (router etc.), the broadcasting packet sent due to dhcp client directly cannot stride across subnet propagation, therefore need to start DHCP proxy in access device, after DHCP proxy listens to the broadcasting packet that dhcp client sends, pre-configured Dynamic Host Configuration Protocol server can be transmitted to.
Dhcp client initiates the application process of IP address, as shown in Figure 3, dhcp client is by DHCP-DISCOVER broadcasting packet to the Dynamic Host Configuration Protocol server application IP address on network and configuration information, and Dynamic Host Configuration Protocol server is according to the request of the configuration response dhcp client of self.
Dhcp client by the specifying information of self, as information such as the IP addresses that last time uses, can be attached in DHCP-DISCOVER broadcasting packet and sends Dynamic Host Configuration Protocol server to, as configuration suggestion.
Because dhcp client itself does not know the address of Dynamic Host Configuration Protocol server, therefore, the target MAC (Media Access Control) address of the DHCP-DISCOVER broadcasting packet that it sends is broadcast address, and this broadcasting packet can be listened to by with the All hosts in same subnet residing for this dhcp client.If by the sensitive information that this DHCP-DISCOVER broadcasting packet is subsidiary relevant with this dhcp client, then the information of this dhcp client is easy to be revealed, and causes network security problem.
Summary of the invention
For the defect existed in prior art, the object of the present invention is to provide a kind of method and system improving DHCP protocol safety, by re-constructing DHCP-DISCOVER unicast message, uploading sensitive information, solving the problem that dhcp client uploads information leakage in sensitive information process.
For reaching above object, the technical scheme that the present invention takes is:
Improve a method for DHCP protocol safety, it is characterized in that, comprise the steps:
Step 1, dhcp client sends DHCP-DISCOVER broadcasting packet, then waits for the response from Dynamic Host Configuration Protocol server;
Step 2, Dynamic Host Configuration Protocol server receives DHCP-DISCOVER broadcasting packet, and then send response message to dhcp client, described response message includes but not limited to DHCP-OFFER response message;
Step 3, dhcp client receives response message, from response message, then extract the MAC Address of Dynamic Host Configuration Protocol server;
Step 4, dhcp client is by the MAC Address of the Dynamic Host Configuration Protocol server of acquisition in step 3, and the target MAC (Media Access Control) address in DHCP-DISCOVER broadcasting packet described in replacement step 1, obtains DHCP-DISCOVER unicast message;
Step 5, the sensitive information transmitted as required, dhcp client, by the DHCP option being defined in affix needs in DHCP-DISCOVER unicast message of DHCP agreement, forms the DHCP-DISCOVER unicast message containing sensitive information;
Step 6, the DHCP-DISCOVER unicast message containing sensitive information sends by dhcp client;
Step 7, Dynamic Host Configuration Protocol server receives the DHCP-DISCOVER unicast message containing sensitive information, and then sends response message to dhcp client.
On the basis of technique scheme, dhcp client and Dynamic Host Configuration Protocol server are arranged in same subnet, and the message between dhcp client and Dynamic Host Configuration Protocol server is is directly received and dispatched.
On the basis of technique scheme, dhcp client and Dynamic Host Configuration Protocol server are arranged in different sub-network, be provided with access device between two subnets, described access device possesses DHCP proxy function, and the message between dhcp client and Dynamic Host Configuration Protocol server is forwarded by DHCP proxy.
Adopt a system for the raising DHCP protocol safety of said method, it is characterized in that, comprising: dhcp client, Dynamic Host Configuration Protocol server,
Described Dynamic Host Configuration Protocol server is described dhcp client distributing IP address,
Dhcp client obtains the MAC Address of described Dynamic Host Configuration Protocol server from the response message to DHCP-DISCOVER broadcasting packet, and reconstructing the DHCP-DISCOVER unicast message that target MAC (Media Access Control) address is the MAC Address of Dynamic Host Configuration Protocol server, dhcp client utilizes DHCP-DISCOVER unicast message to send sensitive information to Dynamic Host Configuration Protocol server.
On the basis of technique scheme, access device, starts DHCP proxy in described access device, and described DHCP proxy plays the effect E-Packeted, and DHCP proxy forwards DHCP packet according to DHCP agreement in the network system of multisegment.
On the basis of technique scheme, described access device is router.
The method and system of raising DHCP protocol safety of the present invention, by re-constructing DHCP-DISCOVER unicast message, uploading sensitive information, solving the problem that dhcp client uploads information leakage in sensitive information process.
Dhcp broadcast message, by strengthening the function of DHCP agreement, is converted to unicast message, uploads sensitive information by unicast message, can strengthen the fail safe of DHCP message, prevent the information leakage of user by the present invention, improves the fail safe of network information transfer.
Accompanying drawing explanation
The present invention has following accompanying drawing:
The classical group net mode one of the existing DHCP protocol system of Fig. 1,
The classical group net mode two of the existing DHCP protocol system of Fig. 2,
The existing dhcp client of Fig. 3 initiates the application process schematic diagram of IP address,
Fig. 4 dhcp client of the present invention initiates the application process schematic diagram of IP address,
Fig. 5 networking mode schematic diagram one of the present invention,
Fig. 6 networking mode schematic diagram two of the present invention,
Fig. 7 the present invention is message interaction schematic diagram when single network segment,
Fig. 8 the present invention is message interaction schematic diagram when multisegment.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described in further detail.
As shown in Fig. 4 ~ 8, the method for raising DHCP protocol safety of the present invention, comprises the steps:
Step 1, dhcp client sends DHCP-DISCOVER broadcasting packet, then waits for the response from Dynamic Host Configuration Protocol server;
Broadcasting packet refers to that in IP message, target MAC (Media Access Control) address is the message of broadcast address, and this message can be received by all computers in same subnet; Change a kind of saying, Ke Yishi: this message can be received by all computers in same broadcast domain or the network equipment;
Step 2, Dynamic Host Configuration Protocol server receives DHCP-DISCOVER broadcasting packet, and then send response message to dhcp client, described response message includes but not limited to DHCP-OFFER response message;
The response message of Dynamic Host Configuration Protocol server can be DHCP-OFFER response message, also can be the message of other any type of dhcp server response;
Step 3, dhcp client receives response message, from response message, then extract the MAC Address of Dynamic Host Configuration Protocol server;
Step 4, dhcp client is by the MAC Address of the Dynamic Host Configuration Protocol server of acquisition in step 3, and the target MAC (Media Access Control) address in DHCP-DISCOVER broadcasting packet described in replacement step 1, obtains DHCP-DISCOVER unicast message;
Unicast message refers to that in IP message, target MAC (Media Access Control) address is the message of the MAC Address of described Dynamic Host Configuration Protocol server, only has the equipment mated with this MAC Address to receive;
Step 5, the sensitive information transmitted as required, dhcp client, by the DHCP option being defined in affix needs in DHCP-DISCOVER unicast message of DHCP agreement, forms the DHCP-DISCOVER unicast message containing sensitive information;
Step 6, the DHCP-DISCOVER unicast message containing sensitive information sends by dhcp client;
Step 7, Dynamic Host Configuration Protocol server receives the DHCP-DISCOVER unicast message containing sensitive information, and then sends response message to dhcp client.
In the present invention, in order to improve and guarantee the fail safe of DHCP agreement, dhcp client obtains the MAC Address of described Dynamic Host Configuration Protocol server from the response message to DHCP-DISCOVER broadcasting packet, then DHCP-DISCOVER unicast message is reconstructed accordingly, dhcp client utilizes DHCP-DISCOVER unicast message to send sensitive information to server, the equipment (Dynamic Host Configuration Protocol server) mated with this MAC Address is only had to receive, the information leakage of user can be prevented, improve the fail safe of network information transfer.
On the basis of technique scheme, dhcp client and Dynamic Host Configuration Protocol server are arranged in same subnet, and the message between dhcp client and Dynamic Host Configuration Protocol server is is directly received and dispatched.
On the basis of technique scheme, dhcp client and Dynamic Host Configuration Protocol server are arranged in different sub-network, be provided with access device between two subnets, described access device possesses DHCP proxy function, and the message between dhcp client and Dynamic Host Configuration Protocol server is forwarded by DHCP proxy.
In conjunction with said method, the present invention gives a kind of system improving DHCP protocol safety, comprising: dhcp client, Dynamic Host Configuration Protocol server,
Described Dynamic Host Configuration Protocol server is described dhcp client distributing IP address,
Dhcp client obtains the MAC Address of described Dynamic Host Configuration Protocol server from the response message to DHCP-DISCOVER broadcasting packet, and reconstructing the DHCP-DISCOVER unicast message that target MAC (Media Access Control) address is the MAC Address of Dynamic Host Configuration Protocol server, dhcp client utilizes DHCP-DISCOVER unicast message to send sensitive information to Dynamic Host Configuration Protocol server.
On the basis of technique scheme, also comprise: access device, start DHCP proxy in described access device, described DHCP proxy plays the effect E-Packeted, and DHCP proxy forwards DHCP packet according to DHCP agreement in the network system of multisegment.
On the basis of technique scheme, described access device is router.
Networking mode one of the present invention as shown in Figure 5, this system comprises: Dynamic Host Configuration Protocol server and dhcp client, wherein all have employed the method introduced in the present invention in Dynamic Host Configuration Protocol server and dhcp client, fail safe strengthened, its message interaction step as shown in Figure 7:
Step 601, first dhcp client initiates DHCP request, sends DHCP-DISCOVER broadcasting packet, the MAC Address of the Dynamic Host Configuration Protocol server on network is not known due to dhcp client, therefore, the target MAC (Media Access Control) address in this message is broadcast address, and not additional any sensitive information;
Step 602, the Dynamic Host Configuration Protocol server being in same subnet with dhcp client receives broadcasting packet that dhcp client sends and responds the request of this client;
Step 603, after dhcp client receives the response message of server, extract the source MAC in response message, the i.e. MAC Address of Dynamic Host Configuration Protocol server, DHCP-DISCOVER unicast message is reconstructed using this MAC Address as target MAC (Media Access Control) address, simultaneously by the DHCP option being defined in any needs of affix in this message of DHCP agreement, form new message and send.
Networking mode two of the present invention as shown in Figure 6, this system comprises: Dynamic Host Configuration Protocol server, dhcp client and start the routing device (access device) of DHCP proxy, wherein all have employed the method introduced in the present invention in Dynamic Host Configuration Protocol server and dhcp client, strengthen fail safe, DHCP proxy is then without any need for change.Be configured with the IP address of Dynamic Host Configuration Protocol server in DHCP proxy in this example, therefore, DHCP proxy can forward DHCP request to Dynamic Host Configuration Protocol server.Its message interaction step is as shown in Figure 8:
Step 701, first dhcp client initiates DHCP request, sends DHCP-DISCOVER broadcasting packet, the MAC Address of the Dynamic Host Configuration Protocol server on network is not known due to dhcp client, therefore, the target MAC (Media Access Control) address in this message is broadcast address, and not additional any sensitive information;
Step 702, according to routing forwarding principle, in default situations, router does not forward broadcast packet.Start DHCP proxy in router, DHCP proxy can listen to DHCP-DISCOVER broadcasting packet.Due to the IP address of Dynamic Host Configuration Protocol server pre-configured in DHCP proxy, therefore DHCP proxy can with mode of unicast by DHCP-DISCOVER Packet forwarding to Dynamic Host Configuration Protocol server;
Step 703, Dynamic Host Configuration Protocol server responds above-mentioned message, sends DHCP-OFFER to DHCP proxy;
Step 704, DHCP proxy forwards DHCP-OFFER message to dhcp client;
Step 705, after dhcp client receives the response message of DHCP proxy, extract the source MAC in response message, the i.e. MAC Address of DHCP proxy, with this MAC Address as target MAC (Media Access Control) address reconstruct DHCP-DISCOVER unicast message, simultaneously by the DHCP option being defined in any needs of affix in this message of DHCP agreement, form new message and send.
Described above is exemplary embodiment of the present invention, for explaining the present invention, but can not limit interest field of the present invention with this, therefore according to the equivalent variations that the present patent application the scope of the claims is done, still belonging to the scope that the present invention is contained.
The content be not described in detail in this specification belongs to the known prior art of professional and technical personnel in the field.
Claims (6)
1. improve a method for DHCP protocol safety, it is characterized in that, comprise the steps:
Step 1, dhcp client sends DHCP-DISCOVER broadcasting packet, then waits for the response from Dynamic Host Configuration Protocol server;
Step 2, Dynamic Host Configuration Protocol server receives DHCP-DISCOVER broadcasting packet, and then send response message to dhcp client, described response message includes but not limited to DHCP-OFFER response message;
Step 3, dhcp client receives response message, from response message, then extract the MAC Address of Dynamic Host Configuration Protocol server;
Step 4, dhcp client is by the MAC Address of the Dynamic Host Configuration Protocol server of acquisition in step 3, and the target MAC (Media Access Control) address in DHCP-DISCOVER broadcasting packet described in replacement step 1, obtains DHCP-DISCOVER unicast message;
Step 5, the sensitive information transmitted as required, dhcp client, by the DHCP option being defined in affix needs in DHCP-DISCOVER unicast message of DHCP agreement, forms the DHCP-DISCOVER unicast message containing sensitive information;
Step 6, the DHCP-DISCOVER unicast message containing sensitive information sends by dhcp client;
Step 7, Dynamic Host Configuration Protocol server receives the DHCP-DISCOVER unicast message containing sensitive information, and then sends response message to dhcp client.
2. the method improving DHCP protocol safety as claimed in claim 1, it is characterized in that: dhcp client and Dynamic Host Configuration Protocol server are arranged in same subnet, the message between dhcp client and Dynamic Host Configuration Protocol server is is directly received and dispatched.
3. the method improving DHCP protocol safety as claimed in claim 1, it is characterized in that: dhcp client and Dynamic Host Configuration Protocol server are arranged in different sub-network, access device is provided with between two subnets, described access device possesses DHCP proxy function, and the message between dhcp client and Dynamic Host Configuration Protocol server is forwarded by DHCP proxy.
4. adopt a system for the raising DHCP protocol safety of method described in claim 1 or 2 or 3, it is characterized in that, comprising: dhcp client, Dynamic Host Configuration Protocol server,
Described Dynamic Host Configuration Protocol server is described dhcp client distributing IP address,
Dhcp client obtains the MAC Address of described Dynamic Host Configuration Protocol server from the response message to DHCP-DISCOVER broadcasting packet, and reconstructing the DHCP-DISCOVER unicast message that target MAC (Media Access Control) address is the MAC Address of Dynamic Host Configuration Protocol server, dhcp client utilizes DHCP-DISCOVER unicast message to send sensitive information to Dynamic Host Configuration Protocol server.
5. the system improving DHCP protocol safety as claimed in claim 4, it is characterized in that, also comprise: access device, DHCP proxy is started in described access device, described DHCP proxy plays the effect E-Packeted, and DHCP proxy forwards DHCP packet according to DHCP agreement in the network system of multisegment.
6. the system improving DHCP protocol safety as claimed in claim 5, is characterized in that: described access device is router.
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| CN110351399A (en) * | 2019-07-04 | 2019-10-18 | 四川天邑康和通信股份有限公司 | A kind of gateway terminal LAN side address dynamic allocation management method and managing device |
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Cited By (2)
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| CN110351399A (en) * | 2019-07-04 | 2019-10-18 | 四川天邑康和通信股份有限公司 | A kind of gateway terminal LAN side address dynamic allocation management method and managing device |
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| CN105376346B (en) | 2018-12-14 |
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Effective date of registration: 20190320 Address after: Room 302, Block B, International Pioneer Park, No. 1 Information Road, Haidian District, Beijing, 100871 Patentee after: Beijing Aike Network Communications Technology Co.,Ltd Address before: Room 302, Block B, International Pioneer Park, No. 1 Information Road, Haidian District, Beijing, 100871 Co-patentee before: ZHEJIANG ACKNETWORKS TECHNOLOGY CO., LTD. Patentee before: Beijing Aike Network Communications Technology Co.,Ltd |