CN106534050A - Method and device for realizing key agreement of virtual private network (VPN) - Google Patents

Abstract

The present invention discloses a method and device for realizing virtual private network key negotiation, including: after a terminal needs to initiate a VPN server connection, if the terminal has stored a root key, then according to the root key, the terminal's B -TID and the NAF_id of the VPN server determine the first shared key, and send the determined first shared key and the B-TID to the VPN server; if a successful authentication response from the VPN server is received, the key is determined to be completed negotiate. The present invention uses the shared key as the session key between the client and the server, and generates the first shared key according to the stored root key, the B-TID of the terminal, and the NAF_id of the VPN server, eliminating the need for the existing VPN Each authentication requires a repeated process of renegotiation, so its generation speed is extremely fast, which reduces the key negotiation delay, reduces system resource consumption, and optimizes the VPN experience.

Description

A method and device for realizing virtual private network key negotiation

technical field

The invention relates to the technical field of communication, in particular to a method and device for realizing virtual private network key negotiation.

Background technique

Virtual Private Network (VPN, Virtual Private Network), its function is to establish a private network on a shared network for encrypted communication. It is widely used in enterprise network. The VPN gateway realizes remote access by encrypting the data packet and converting the destination address of the data packet. There are many classification methods of VPN, which can be divided into multi-protocol label switching virtual private network (MPLS VPN, Multiprotocol LabelSwitching VPN), secure socket layer virtual private network (SSL VPN, Security Socket Layer VPN) and IP protocol security structure virtual network according to the protocol method. Private network (IPSec VPN, Security Architecture for IP NetworkVPN), can be divided into server, hardware, software, etc. according to the implementation method. VPNs are cheap and easy to use. Among all VPN technologies, SSL VPN is the simplest and most secure solution for remote users to access sensitive company data. Based on the mature SSL protocol, SSL VPN does not require special client software support. It uses public key certificates for authentication between the client and the server, and then negotiates to generate a symmetric key for encrypted communication between the two parties to ensure the security of data transmission.

However, SSL VPN still has certain deficiencies in application deployment:

First of all, enterprise SSL VPN often requires employees to first use the assigned user name and password for identity authentication. Inconvenience is caused, and employees who lack responsibility may set a simple password for the convenience of use, which brings great security risks to corporate information leakage;

Secondly, the existing SSL VPN authentication is based on public key certificates for key negotiation. The client and server need to go through multiple interactive negotiations to finally generate a shared key for transmission protection. This process is very time-consuming, and every After a VPN connection, renegotiation still needs to be renegotiated, which consumes a lot of system resources. If a shared key is stored for a long time and can be used for a VPN connection within a period of time, problems are more likely to occur. First, the server It is necessary to save the shared key for each user, which increases the maintenance cost. At the same time, on the terminal side, since the key can only be stored at the application layer, it is very easy to be stolen by malicious programs on the terminal, resulting in key leakage. Therefore, SSL VPN uses Historical keys are extremely insecure;

Finally, in order to pursue negotiation speed, key negotiation in SSL VPN authentication often adopts one-way authentication, that is, only the server has a public key certificate, and only the client needs to authenticate the server during negotiation, while the server does not need to authenticate the client. Compared with two-way authentication, this also brings opportunities for attackers.

To sum up, the existing SSL VPN authentication needs to use username and password for authentication, which not only causes inconvenient use, but also easily leads to the leakage of confidential information, which is extremely unsafe; in addition, when negotiating a shared key every time Renegotiation and multiple interactions are required to generate the shared key, which not only takes time but also wastes system resources.

Contents of the invention

Embodiments of the present invention provide a method and device for implementing virtual private network key agreement, which are used to solve the problems of low security, long time and waste of system resources in SSL VPN authentication in the prior art.

A method for implementing virtual private network key negotiation provided by an embodiment of the present invention includes:

After the terminal needs to initiate a virtual private network VPN server connection, if the terminal has stored the root key, then according to the root key, the terminal bootstrapping identifier (B-TID, Bootstrapping TransactionIdentifier) and the network application identifier (NAF_id) of the VPN server , Network ApplicationFunction Identifier) determine the first shared key, and send the determined first shared key and the B-TID to the VPN server;

If the authentication success response from the VPN server is received, it is determined that the key negotiation is completed.

Optionally, after the terminal needs to initiate a VPN server connection, it also includes:

If the terminal does not store the root key, the terminal negotiates with the authentication service function BSF network element to determine the root key and B-TID, and executes the step of determining the first shared key.

Optionally, the terminal negotiates with the BSF network element to determine the root key and the B-TID, specifically including:

The terminal sends the user identification to the BSF network element;

The terminal performs verification according to the received random number and authentication mark from the BSF network element, and determines the encryption key, the integrity key and the authentication data response RES after the verification is passed;

The terminal requests authentication from the BSF network element according to the authentication data response, and after the authentication is passed, receives the B-TID of the terminal from the BSF network element, and determines the root key according to the encryption key and the integrity key key.

A method for implementing virtual private network key negotiation provided by an embodiment of the present invention includes:

After receiving the B-TID of the terminal sent by the VPN server and the NAF_id of the VPN server, the BSF network element determines the root key corresponding to the B-TID according to the binding relationship between the B-TID and the root key;

The BSF network element determines a second shared key according to the B-TID, the NAF_id and the root key;

The BSF network element returns the determined second shared key to the VPN server, so that the VPN server authenticates the terminal according to the received second shared key.

Optionally, the BSF establishes the binding relationship between the B-TID and the root key in the following manner:

The BSF network element obtains an authentication quintuple authentication vector from the network side according to the received user identifier sent by the terminal;

The BSF network element sends the random number and the authentication mark in the authentication quintuple authentication vector to the terminal;

After the BSF network element receives the authentication data response from the terminal, it authenticates the terminal through the encryption key, the integrity key and the expected response value XRES in the authentication quintuple authentication vector, and After passing the authentication, determine the root key and the B-TID of the terminal according to the encryption key and the integrity key, and establish the binding relationship between the B-TID and the root key.

Optionally, after the BSF determines the root key and the B-TID according to the encryption key and the integrity key, it further includes:

The BSF sends the B-TID to the terminal.

A method for implementing virtual private network key negotiation provided by an embodiment of the present invention includes:

The VPN server receives the first shared key and B-TID sent by the terminal, and sends the B-TID and the NAF_id of the VPN server to the BSF network element;

The VPN server receives the second shared key returned by the BSF network element;

the VPN server compares the first shared key with a second shared key;

If the first shared key and the second shared key are the same, return an authentication success response to the terminal.

A terminal for implementing virtual private network key negotiation provided by an embodiment of the present invention includes:

The first determining module is used to initiate a virtual private network VPN server connection, if the root key has been stored, then according to the root key, the terminal bootstrapping identifier (B-TID, Bootstrapping TransactionIdentifier) and the network application of the VPN server The identifier (NAF_id, Network ApplicationFunction Identifier) determines the first shared key, and sends the determined first shared key and the B-TID to the VPN server;

The first receiving module is configured to determine that the key agreement is completed if the authentication success response from the VPN server is received.

Optionally, the first determining module is also used for:

After the need to initiate a VPN server connection, if the root key is not stored, negotiate with the authentication service function BSF network element to determine the root key and B-TID, and execute the step of generating the first shared key.

Optionally, the first determining module is also used for:

Negotiate with the BSF network element to determine the root key and B-TID, send the user ID to the BSF network element; perform verification according to the received random number and authentication mark from the BSF network element, and determine the encryption key, Integrity key and authentication data response RES; request authentication from the BSF network element according to the authentication data response, and after the authentication is passed, receive the B-TID of the terminal from the BSF network element, and according to the encryption key and the integrity key to determine the root key.

A BSF network element that implements virtual private network key negotiation provided by an embodiment of the present invention includes:

The query module is used to determine the root key corresponding to the B-TID according to the binding relationship between the B-TID and the root key after receiving the terminal B-TID sent by the VPN server and the NAF_id of the VPN server;

A second determining module, configured to determine a second shared key according to the B-TID, the NAF_id, and the root key;

A sending module, configured to return the determined second shared key to the VPN server, so that the VPN server authenticates the terminal according to the received second shared key.

Optionally, the query module is specifically used for:

Establish the binding relationship between the B-TID and the root key in the following manner: according to the received user identification sent by the terminal, obtain the authentication quintuple authentication vector from the network side; Send the random number and authentication information to the terminal; after receiving the authentication data response from the terminal, pass the encryption key, integrity key and response response expectation value XRES in the authentication quintuple authentication vector to the terminal Perform authentication, and after the authentication is passed, determine the root key and the B-TID of the terminal according to the encryption key and the integrity key, and establish the binding relationship between the B-TID and the root key.

Optionally, the sending module is specifically used for:

After the root key and the B-TID are determined according to the encryption key and the integrity key, the B-TID is sent to the terminal.

A VPN server for implementing virtual private network key negotiation provided by an embodiment of the present invention includes:

The transceiver module is used to receive the first shared key and B-TID sent by the terminal, and send the B-TID and the NAF_id of the VPN server to the BSF network element;

The second receiving module is used to receive the second shared key returned by the BSF network element;

a comparison module, configured to compare the first shared key with the second shared key;

A processing module, configured to return an authentication success response to the terminal if the first shared key and the second shared key are the same.

In the embodiment of the present invention, after the terminal needs to initiate a VPN server connection, if the terminal has stored the root key, then determine the first shared key according to the root key, the B-TID of the terminal, and the NAF_id of the VPN server, And send the determined first shared key and the B-TID to the VPN server; if a successful authentication response from the VPN server is received, it is determined to complete the key negotiation. Compared with the existing SSLVPN authentication negotiation, the method for realizing virtual private network key negotiation provided by the embodiment of the present invention uses the shared key as the session key between the client and the server, and according to the stored root key, The B-TID of the terminal and the NAF_id of the VPN server generate the first shared key, which avoids the repeated process of renegotiation for each authentication in the existing VPN, so the generation speed is extremely fast, which reduces the key negotiation delay and reduces Reduced system resource consumption and optimized VPN experience;

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is one of the flow charts of the method for realizing virtual private network key negotiation provided by the embodiment of the present invention;

Fig. 2 is the second flow chart of the method for implementing virtual private network key negotiation provided by the embodiment of the present invention;

Fig. 3 is a schematic flow diagram of implementing virtual private network root key negotiation provided by an embodiment of the present invention;

Fig. 4 is the third flow chart of the method for implementing virtual private network key negotiation provided by the embodiment of the present invention;

FIG. 5 is a schematic flow diagram for implementing virtual private network shared key negotiation provided by an embodiment of the present invention;

FIG. 6 is an example diagram for realizing virtual private network key negotiation provided by an embodiment of the present invention;

FIG. 7 is an architecture diagram for implementing key agreement between a single APP and multiple VPN servers provided by an embodiment of the present invention;

FIG. 8 is a flowchart of a terminal for implementing virtual private network key negotiation provided by an embodiment of the present invention;

FIG. 9 is a flowchart of a BSF network element implementing virtual private network key negotiation provided by an embodiment of the present invention;

FIG. 10 is a flow chart of a VPN server for realizing virtual private network key negotiation provided by an embodiment of the present invention.

detailed description

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The method for implementing virtual private network key negotiation provided by the embodiment of the present invention can be applied to a terminal, as shown in FIG. 1 , and specifically includes the following steps:

Step 101: After the terminal needs to initiate a VPN server connection, if the terminal has stored the root key, determine the first shared key according to the root key, the B-TID of the terminal, and the NAF_id of the VPN server, and determine The first shared key and the B-TID are sent to the VPN server;

Step 102, if the authentication success response from the VPN server is received, it is determined that the key negotiation is completed.

Optionally, in the above step 101, a dedicated VPN APP is installed on the terminal, and the APP can be used to realize the interaction between the terminal and the VPN server. When the terminal initiates a VPN server that needs to be connected, it checks whether the root key (Ks, Keystore) is currently stored, and if it has been stored, then the first shared key is determined according to the root key Ks, the B-TID of the terminal, and the NAF_id of the VPN server. key (Ks_NAF1, Keystore_Network Application Function), and send the determined first shared key Ks_NAF1 and the B-TID to the VPN server.

Specifically, the terminal determines the first shared key according to the root key Ks, the B-TID of the terminal, and the NAF_id of the VPN server, specifically Ks_NAF1=KDF(Ks, "gba-me", RAND, IMPI, NAP_ID), Among them, KDF is the key guidance algorithm (KDF, KeyDerivationFunction), RAND is the random number (RAND, Random Number) generated by BSF when negotiating Ks, IMPI is the IP multimedia private identity (IMPI, IP Multimedia Private Identity) of the terminal, NAF_ID is The web application ID of the business.

Optionally, when the terminal sends the first shared key and the B-TID to the VPN server, it may encrypt the first shared key, and encrypt the encrypted first shared key, the terminal's B-TID is sent to the VPN server together. For example, the terminal generates an authentication random number rand, encrypts it with the first shared key, generates a random number ciphertext encrand, and sends the rand, encrand, and B-TID to the VPN server.

In step 101, after the terminal needs to initiate a VPN server connection, if the terminal does not store the root key Ks, the terminal negotiates with the authentication service function (BSF, Bootstrapping Server Function) network element to determine the root key Ks and B -TID, and perform the step of generating a first shared key.

Specifically, the terminal negotiates with the BSF network element to determine the root key Ks and B-TID, including:

The terminal sends the user identification to the BSF network element; according to the received random number RAND and the authentication token (AUTN, Authentication Token) from the BSF network element, it is verified through the authentication algorithm, and the encryption key (CK, Cipher Key), integrity key (IK, Integrity Key) and authentication data response (RES, Response); according to the authentication data response RES to request authentication from the BSF network element, and after the authentication is passed, receive the authentication data from the BSF network element The B-TID of the terminal, and determine the root key Ks according to the encryption key CK and the integrity key IK. Optionally, the subscriber identity may be an IP Multimedia Private Identity (IMPI, IP Multimedia Private Identity), or an International Mobile Subscriber Identity (IMSI, International Mobile Subscriber Identity).

Further, after the terminal negotiates with the BSF network element to determine the root key and the B-TID, it executes the step of generating the first shared key.

Among them, the root key Ks is a type of shared key that can be stored and has a validity period that can be set. It can be reused within the validity period. Ks is initialized after negotiation between the client and the BSF network element, and then stored in the SIM card and BSF. It has high storage security.

If the root key exceeds the validity period, the root key negotiation process is performed again to establish a new binding relationship between the B-TID and the root key.

Further, after the terminal determines the first shared key through step 101, and sends the determined first shared key and the B-TID to the VPN server, it receives an authentication success response from the VPN server, and determines that the key negotiation is completed .

In the VPN authentication and key agreement method provided by the embodiment of the present invention, through the negotiation of the root key and the shared key generated by extending the root key, it is realized that the traditional SSL VPN needs to renegotiate the shared key every time. The key process is optimized, and because the root key is stored in the terminal and BSF, it has high storage security, which greatly improves the security and performance of VPN.

The method for realizing virtual private network VPN authentication and key negotiation provided by the embodiment of the present invention can be applied to a BSF network element, as shown in FIG. 2 , specifically comprising the following steps:

Step 201: After receiving the B-TID of the terminal and the NAF_id of the VPN server sent by the VPN server, the BSF network element determines the root key corresponding to the B-TID according to the binding relationship between the B-TID and the root key key;

Step 202, the BSF network element determines a second shared key according to the B-TID, the NAF_id and the root key;

Step 203, the BSF network element returns the determined second shared key to the VPN server, so that the VPN server authenticates the terminal according to the received second shared key.

Specifically, when executing step 201, the BSF network element establishes the binding relationship between the B-TID and the root key in the following manner:

The BSF network element obtains an authentication quintuple authentication vector from the network side according to the received user identifier sent by the terminal;

The BSF network element sends the random number and authentication information in the authentication quintuple authentication vector to the terminal;

After the BSF network element receives the authentication data response from the terminal, it uses the encryption key, integrity key and expected response value (XRES, ExpectedResponse) in the authentication quintuple authentication vector to the terminal Perform authentication, and after the authentication is passed, determine the root key and the B-TID of the terminal according to the encryption key and the integrity key, and establish the binding relationship between the B-TID and the root key.

Optionally, the BSF network element obtains the authentication quintuple authentication vector from the network side according to the received user identifier sent by the terminal, specifically: the BSF network element obtains the authentication vector from the Home Subscriber Server (HSS, HomeSubscriber Server) The authentication quintuple authentication vector corresponding to the user identifier, the HSS returns the authentication quintuple authentication vector AV=RAND||AUTN||XRES||CK||IK according to the user identifier, where RAND is a random number, ensuring that each The Ks of each negotiation are different, AUTN is an authentication mark, which needs to be verified by the terminal, XRES is used for authentication of the authentication information returned by the terminal, and CK and IK are used to generate Ks.

Optionally, after receiving the authentication vector AV from the HSS, the BSF network element returns RAND and AUTN to the terminal, requiring the terminal to authenticate the BSF network element, and the XRES, CK, and IK information are stored locally in the BSF.

Optionally, after receiving the authentication data response from the terminal, the BSF network element authenticates the terminal through the stored CK, IK, and XRES, and calculates the root key Ks=CK||IK after the authentication is passed , and generate the value of B-TID at the same time, B-TID=base64encode(RAND)@BSF_servers_domain_name.

Further, the BSF network element sends the B-TID to the terminal after determining the root key Ks and the B-TID according to the CK and IK.

After step 201 is executed, the BSF network element determines the second shared key Ks_NAF2 according to the B-TID, the NAF_id and the root key.

Specifically, the BSF network element determines the second shared key Ks_NAF2 according to the B-TID, the NAF_id, and the root key, specifically, Ks_NAF2=KDF(Ks, "gba-me", RAND, IMPI, NAP_ID ), wherein, KDF is a key guidance algorithm (KDF, KeyDerivationFunction), RAND is a random number (RAND, Random Number) generated by BSF when negotiating Ks, and IMPI is an IP multimedia private identity (IMPI, IP Multimedia Private Identity) of a terminal, NAF_ID is the network application identifier of the service.

In step 203, the BSF network element returns the second shared key determined in step 202 to the VPN server, so that the VPN server authenticates the terminal according to the received second shared key.

The above-mentioned method for realizing virtual private network VPN authentication and key negotiation provided by the embodiment of the present invention is based on the authentication method of the terminal SIM card and the network side authentication quintuple, which replaces the traditional SSL VPN that needs to use the username and password method for authentication The authentication system eliminates the leakage of confidential information caused by password cracking, improves system security, reduces user participation in the authentication process, and greatly optimizes the VPN authentication process. In addition, in the presence of the root key Ks In this case, user identity authentication and shared key negotiation are completed in one negotiation process, which simplifies the authentication negotiation process and greatly improves the efficiency of VPN authentication negotiation while ensuring security.

A specific embodiment is given below with reference to FIG. 3 , and how the technical solution of the present invention realizes the negotiation of the virtual private network root key Ks.

As shown in Figure 3, the terminal equipment (UE, User Equipment) carries the user information IMPI to initiate an initialization request to the BSF; after receiving the request from the UE, the BSF obtains the user information corresponding to the IMPI from the HSS, and the HSS returns the authentication code according to the IMPI. Tuple authentication vector AV=RAND||AUTH||XRES||CK||IK, where RAND is a random number to ensure that the Ks of each negotiation is different, AUTH is authentication information, which needs to be verified by UE, and XRES is used for UE The returned authentication information is authenticated, CK and IK are used to generate Ks; BSF receives the authentication vector AV of HSS, returns RAND and AUTN to UE, and requires UE to authenticate BSF, and XRES, CK, and IK information are stored locally in BSF; After receiving RAND and AUTH, UE verifies AUTN through the authentication algorithm, confirms that the message comes from the authorized network, and calculates CK, IK and RES at the same time. At this time, both BSF and UE have stored CK and IK; UE uses RES to calculate the response and sends it to BSF to request authentication; BSF verifies the correctness of the response through the stored CK, IK, and XRES, and if it is correct, calculates the root key Ks= CK||IK generates the value of B-TID at the same time, B-TID=base64encode(RAND)@BSF_servers_domain_name; BSF sends an authentication success response and B-TID to UE, and informs the validity period of Ks. After receiving the success message, UE also uses CK||IK to calculate Ks. At this time, UE and BSF both save the root key Ks, Ks initialization is completed, and the negotiation ends.

The method for implementing virtual private network key negotiation provided by the embodiment of the present invention can be applied to the server side, as shown in FIG. 4 , and specifically includes the following steps:

Step 401, the VPN server receives the first shared key and the B-TID sent by the terminal, and sends the B-TID and the NAF_id of the VPN server to the BSF network element;

Step 402, the VPN server receives the second shared key returned by the BSF network element;

Step 403, the VPN server compares the first shared key with the second shared key;

Step 404, if the first shared key and the second shared key are the same, return an authentication success response to the terminal.

Specifically, when the VPN server receives the second shared key returned by the BSF network element, it uses the second shared key to verify the first shared key, and if the decrypted content is consistent, the authentication is successful. For example, the VPN server receives the rand (the terminal generates an authentication random number), encrand (generated after encryption using the first shared key) and B-TID sent by the terminal. When the BSF network element returns the second shared key, the VPN server 2. The shared key verifies the encrand. If the decrypted content is consistent with the rand, the authentication is successful.

A specific embodiment is given below with reference to FIG. 5 , and how the technical solution of the present invention realizes the negotiation of the virtual private network shared key.

As shown in Figure 5, the UE selects the VPN server it wants to connect to on the APP, and the APP sends the NAF_id of the selected server to the UE and applies for a shared key; the UE checks whether the root key Ks is currently stored, and if so, according to the -TID and the received NAF_id generate Ks_naf, if it does not exist, negotiate Ks with BSF according to the Ks initialization process in Figure 5, and then generate the first shared key Ks_naf1; UE sends the generated Ks_naf1 and B-TID to APP; APP Generate the authentication random number rand, encrypt it with Ks_naf1 to generate encrand, and send rand, encrand, and B-TID to the VPN server to request authentication and ask the server to also generate a shared key; after receiving the request, the VPN server combines B-TID with NAF_id is sent to BSF, BSF also generates Ks_naf2 according to Ks, B-TID and NAF_id, and returns to VPN server through a secure channel; VPN server verifies encrand according to Ks_naf2 returned by BSF, if the decrypted content is consistent with rand, the authentication is successful , returns the APP authentication success response; APP receives the authentication success response, at this time, both the APP and the VPN server have the shared key Ks_naf, and the key negotiation is successful, and the secure communication can be carried out. The VPN authentication and key negotiation process ends.

Referring to the scene in Figure 6 to better discuss the specific implementation process in the embodiment of the present invention, Figure 6 is just an example of the scene, obviously the technical solution of the present invention can be applied to any scene of VPN key negotiation.

As shown in Figure 6, the general authentication mechanism (GBA, General Bootstrapping Architecture) defines a general key agreement mechanism between the terminal and the server. It can be seen from its architecture model that the specific network elements include:

UE is the general term of terminal equipment and SIM card. In the present invention, it refers to a mobile phone and a mobile terminal that can be inserted into a SIM card. It can be used to negotiate with BSF network elements to determine the root key Ks, and determine the first shared key based on Ks.

The application server (NAF, Network Application Function), implements the business logic function of the application, and provides business services for the terminal after completing the authentication of the terminal. In the present invention, it refers to the enterprise VPN server, which is used to send the received UE A shared key is compared with the received second shared key returned by the BSF network element, and if the first shared key is the same as the second shared key, then an authentication success response is returned to the UE, and security is performed with the terminal. communication.

The BSF is the core network element. The BSF and the UE implement authentication through the AKA (Authentication and Key Agreement) protocol, and negotiate a session key for subsequent communication between the UE and the NAF. The BSF can set the The validity period of the key means that in the present invention, the root key Ks is negotiated and determined between the BSF and the UE, and the second shared key is determined based on Ks.

The HSS stores the authentication data in the terminal (U)SIM card. In the present invention, the HSS returns an authentication quintuple authentication vector to the BSF according to the user identification, so that the BSF can authenticate the UE.

The reference points between network elements include:

Ub is an interface for interacting and negotiating a root key (Ks, Root Key) between UE and BSF, and is used for general authentication mechanism process initialization, and subsequent operations depend on Ks.

Zh is the interface for BSF to obtain client authentication information on HSS, which is used for BSF to authenticate client identity and generate root key Ks.

Zn is an interface for interaction between the NAF and the BSF, through which the NAF authenticates the user identity to the BSF and obtains an extended shared key (Ks_naf, Extended Shared Key). In the present invention, the VPN server obtains the same shared key as the client at the BSF through the interface.

Ua is the extended shared key Ks_naf negotiation interface between the UE and the NAF, through which the generation parameters of Ks_naf are transmitted to complete the generation of Ks_naf.

Optionally, as shown in Figure 7, based on the generation characteristics of the shared key, fast identity authentication and shared key negotiation between a single APP and multiple VPN servers can also be realized, which greatly expands the system architecture with more effective technologies and optimizes The effect of using VPN.

Based on the same technical concept, the embodiment of the present invention also provides a device for implementing virtual private network key negotiation, which can execute the above-mentioned method embodiment, because the problem-solving principle of the device is the same as that of the aforementioned one for realizing virtual private network key The method of negotiation is similar, so the implementation of the device can refer to the implementation of the method, and the repetition will not be repeated.

A terminal for implementing virtual private network key negotiation provided by an embodiment of the present invention, as shown in FIG. 8 , includes:

The first determination module 801 is used to determine the first determination module 801 according to the root key, the terminal guide identifier B-TID and the network application identifier NAF_id of the VPN server if the root key has been stored after the virtual private network VPN server connection needs to be initiated. A shared key, and send the determined first shared key and the B-TID to the VPN server;

The first receiving module 802 is configured to determine that the key negotiation is completed if an authentication success response from the VPN server is received.

Optionally, the first determining module 801 is further configured to:

After the need to initiate a VPN server connection, if the root key is not stored, negotiate with the authentication service function BSF network element to determine the root key and B-TID, and execute the step of generating the first shared key.

Optionally, the first determining module 801 is further configured to:

Negotiate with the BSF network element to determine the root key and B-TID, send the user ID to the BSF network element; perform verification according to the received random number and authentication mark from the BSF network element, and determine the encryption key, Integrity key and authentication data response RES; request authentication from the BSF network element according to the authentication data response, and after the authentication is passed, receive the B-TID of the terminal from the BSF network element, and according to the encryption key and the integrity key to determine the root key.

The embodiment of the present invention also provides a BSF network element for implementing virtual private network key negotiation, as shown in FIG. 9 , including:

The query module 901 is configured to determine the root key corresponding to the B-TID according to the binding relationship between the B-TID and the root key after receiving the terminal B-TID sent by the VPN server and the NAF_id of the VPN server ;

The second determination module 902 is configured to determine a second shared key according to the B-TID, the NAF_id and the root key;

The sending module 903 is configured to return the determined second shared key to the VPN server, so that the VPN server authenticates the terminal according to the received second shared key.

Optionally, the query module 901 is specifically used for:

Establish the binding relationship between the B-TID and the root key in the following manner: according to the received user identification sent by the terminal, obtain the authentication quintuple authentication vector from the network side; Send the random number and authentication information to the terminal; after receiving the authentication data response from the terminal, pass the encryption key, integrity key and response response expectation value XRES in the authentication quintuple authentication vector to the terminal Perform authentication, and after the authentication is passed, determine the root key and the B-TID of the terminal according to the encryption key and the integrity key, and establish the binding relationship between the B-TID and the root key.

Optionally, the sending module 903 is specifically configured to:

After the root key and the B-TID are determined according to the encryption key and the integrity key, the B-TID is sent to the terminal.

The embodiment of the present invention also provides a VPN server for implementing virtual private network key negotiation, as shown in FIG. 10 , including:

The transceiver module 1001 is configured to receive the first shared key and the B-TID sent by the terminal, and send the B-TID and the NAF_id of the VPN server to the BSF network element;

The second receiving module 1002 is configured to receive the second shared key returned by the BSF network element;

A comparison module 1003, configured to compare the first shared key with the second shared key;

The processing module 1004 is configured to return an authentication success response to the terminal if the first shared key is the same as the second shared key.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (14)

1. a kind of method for realizing VPN (virtual private network) key agreement, it is characterised in that the method includes：

Terminal is after needing to initiate the connection of VPN (virtual private network) vpn server, if to have stored root close for the terminal Key, then identify according to the network application of root key, terminal guiding mark B-TID and vpn server NAF_id determines the first shared key, and the first shared key for determining and the B-TID are sent to VPN Server；

If receiving the certification success response from vpn server, it is determined that complete key agreement.

2. method according to claim 1, it is characterised in that the terminal is needing to initiate VPN After server connection, also include：

If the non-storage root key of the terminal, terminal consults to determine that root is close with authentication service function BSF network element Key and B-TID, and perform the step of generating the first shared key.

3. method according to claim 2, it is characterised in that the terminal consults true with BSF network elements Determine root key and B-TID, specifically include：

The terminal sends ID to BSF network elements；

The terminal verified according to the random number and certification mark from the BSF network elements that receive, and Encryption key, Integrity Key and authorization data response RES is determined after being verified；

The terminal is responded to BSF network elements according to authorization data and asks certification, and after certification passes through, is received From the B-TID of the terminal of the BSF network elements, and determined according to encryption key and Integrity Key Root key.

4. a kind of method for realizing VPN (virtual private network) key agreement, it is characterised in that the method includes：

B-TID and the NAF_id of vpn server of the BSF network elements in the terminal for receiving vpn server transmission Afterwards, according to the B-TID and the binding relationship of root key, the corresponding root keys of the B-TID are determined；

The BSF network elements determine second according to the B-TID, the NAF_id and the root key Shared key；

The second shared key for determining is back to vpn server by the BSF network elements, so that VPN services Device is authenticated to the terminal according to second shared key for receiving.

5. method according to claim 4, it is characterised in that the BSF is set up according to following manner The binding relationship of B-TID and root key：

The ID that the BSF network elements are sent according to the terminal for receiving, obtains authentication five-tuple from network side Ciphering Key；

Random number in the authentication five-tuple Ciphering Key is sent to end with authentication information by the BSF network elements End；

The BSF network elements are being received after the authorization data response of the terminal, authenticate five yuan by described Encryption key, Integrity Key and response expected value XRES in group Ciphering Key is recognized to terminal Card, and after certification passes through, the B-TID of root key and terminal is determined according to encryption key and Integrity Key, And set up the binding relationship of B-TID and root key.

6. method according to claim 5, it is characterised in that the BSF is according to encryption key and complete After whole property key determines root key and B-TID, also include：

The B-TID is sent to the terminal by the BSF.

7. a kind of method for realizing VPN (virtual private network) key agreement, it is characterised in that the method includes：

The first shared key and B-TID that vpn server receiving terminal sends, and B-TID and VPN is taken The NAF_id of business device is sent to BSF network elements；

The vpn server receives the second shared key that BSF network elements are returned；

First shared key and the second shared key are compared by the vpn server；

If first shared key is identical with the second shared key, to the terminal return authentication success Response.

8. a kind of terminal for realizing VPN (virtual private network) key agreement, it is characterised in that include：

First determining module, for after needing to initiate the connection of VPN (virtual private network) vpn server, if deposit Storage root key, then should according to the network of root key, terminal guiding mark B-TID and vpn server The first shared key is determined with mark NAF_id, and the first shared key for determining and the B-TID are sent out Give vpn server；

First receiver module, if for receiving the certification success response from vpn server, it is determined that complete Into key agreement.

9. terminal according to claim 8, it is characterised in that first determining module is additionally operable to：

After needing to initiate vpn server connection, if non-storage root key, with authentication service function BSF Network element is consulted to determine root key and B-TID, and performs the step of generating the first shared key.

10. terminal according to claim 9, it is characterised in that first determining module is additionally operable to：

Consult to determine root key and B-TID with BSF network elements, ID is sent to BSF network elements；According to receipts The random number and certification mark from BSF network elements for arriving, is verified, and determines encryption after being verified Key, Integrity Key and authorization data response RES；Responded to BSF network elements according to authorization data and asked Certification, and after certification passes through, receive the B-TID, Yi Jigen of the terminal from the BSF network elements Root key is determined according to encryption key and Integrity Key.

11. a kind of BSF network elements for realizing VPN (virtual private network) key agreement, it is characterised in that include：

Enquiry module, in terminal B-TID and vpn server for receiving vpn server transmission After NAF_id, according to the B-TID and the binding relationship of root key, determine that corresponding of the B-TID is close Key；

Second determining module, for according to the B-TID, the NAF_id and the root key, it is determined that Second shared key；

Sending module, for the second shared key for determining is back to vpn server, so that VPN clothes Business device is authenticated to the terminal according to second shared key for receiving.

12. BSF network elements according to claim 11, it is characterised in that the enquiry module is specifically used In：

The binding relationship of B-TID and root key is set up according to following manner：According to the use that the terminal for receiving sends Family identifies, and obtains authentication five-tuple Ciphering Key from network side；By in the authentication five-tuple Ciphering Key Random number is sent to terminal with authentication information；Receiving after the authorization data response of the terminal, passing through Encryption key, Integrity Key and response expected value XRES in the authentication five-tuple Ciphering Key Terminal is authenticated, and after certification passes through, according to encryption key and Integrity Key determine root key and The B-TID of terminal, and set up the binding relationship of B-TID and root key.

13. BSF network elements according to claim 12, it is characterised in that the sending module is specifically used In：

After determining root key and B-TID according to encryption key and Integrity Key, the B-TID is sent To the terminal.

14. a kind of vpn servers for realizing VPN (virtual private network) key agreement, it is characterised in that include：

Transceiver module, the first shared key sent for receiving terminal and B-TID, and by B-TID and VPN The NAF_id of server is sent to BSF network elements；

Second receiver module, for receiving the second shared key of BSF network elements return；

Comparison module, for first shared key and the second shared key are compared；

Processing module, if identical with the second shared key for first shared key, to the end End return authentication success response.