Key generation method, system and device and storage medium

Abstract

The present disclosure relates to the field of wireless communications, and discloses a key generation method, system and device, and a storage medium, the method comprising: in a fast roaming process, a target AP obtains an STA air interface frame; pMKR1 is calculated according to the information in the air interface frame; a random value RNon is calculated according to the PMKR1; and the target AP returns the random value RNon to the STA through a reply air interface frame. According to the invention, the distribution of the PMK R1 key does not need to be carried out through an Ethernet frame, so that wireless network devices produced by different manufacturers can be seamlessly connected and communicated by using an 802.11 r fast roaming protocol.

Description

Technical Field

[0001] The present disclosure relates to the field of wireless communication technology, and in particular to a key generation method, system, device and storage medium. Background Art

[0002] In modern wireless local area networks (WLANs), seamless roaming of devices has become the key to improving user experience. The IEEE802.11r standard, the Fast Transition (FT) protocol, aims to solve the latency problem when devices switch between different access points. By proposing a three-layer key structure, 802.11r can quickly complete re-authentication when devices roam, ensuring the continuity and security of network connections.

[0003] In order to achieve fast roaming, the 802.11r standard specifies a series of key generation and distribution mechanisms. R0KH (PMK-R0 key holder in the Authenticator, the PMK-R0 key management entity on the authenticator side, the authenticator side is the target AP side) generates PMK_R0 and PMK_R1 (Pairwise Master Key_R1) corresponding to each AP (Access Point) during the initial authentication, and distributes PMK_R1 among all access points (Access Point, AP) in the Mobility Domain (MD). Each AP uses these keys to perform fast transition authentication with the terminal (Station, STA) to generate a new PTK (Pairwise Transient Key) for encrypted communication. Since the protocol does not specify the distribution method of PMK_R1, the implementation of the key distribution mechanism varies from manufacturer to manufacturer, and fast roaming cannot be performed. The wired distribution of PMK_R1 key between APs has limited usage scenarios.

[0004] In the 802.11r protocol, when the STA initializes its association with the mobile domain MD for the first time, the R0KH generates the master key PMK_R0 (Pairwise Master Key_R0) and calculates the corresponding subkey PMK_R1 for each R1KH (PMK-R1 key holder in the Authenticator, the PMK-R1 key management entity on the authenticator side, the authenticator side is the target AP side). Subsequently, the R0KH distributes these PMK_R1s to each R1KH in the MD. Thereafter, when the STA roams, it can calculate the PTK using the pre-assigned PMK_R1; if the R1KH of the target AP does not store the PMK_R1 required by the STA, the R0KH recalculates the PMK_R1 and PMKRlName based on the R1KH_ID, and sends them to the requesting R1KH to achieve fast roaming authentication. The key distribution process is as follows: Figure 1 As shown, Figure 1 In the WTP protocol, WTP (Wireless Transaction Protocol) is a communication protocol used in wireless network environments for data transmission and transaction processing between mobile devices; R0KH and R1KH are key management entities on the authenticator (target AP) side. The calculation of PMK_R0 and PMK_R1 is controlled by R0KH. R0KH is also responsible for providing PMK_R1 to R1KH. The calculation of PTK is controlled by R1KH. S0KH is the PMK-S0 key management entity on the applicant (STA) side, and S1KH is the PMK-S1 key management entity on the applicant (STA) side. The functions of S0KH and S1KH correspond to R0KH and R1KH; R0KH-ID is the identifier of R0KH (NAS-ID), which is 1-48 bytes long according to IEEE standards and can be customized by manufacturers. R0KH-ID and R1KH-ID are both the MAC addresses of the authenticator. S0KH-ID and S1KH-ID are both the MAC addresses of the applicant (STA). From this process, it can be seen that the distribution of PMK_R1 runs through the entire roaming authentication process, but because the protocols used by different chip solutions to distribute PMK_R1 are quite different, interoperability cannot be achieved. Therefore, a local key management and distribution mechanism is needed to achieve interoperability between different chip solutions. Summary of the invention

[0005] The embodiments of the present disclosure provide a key generation method, system, device and storage medium to solve or alleviate one or more of the above technical problems in the prior art.

[0006] According to one aspect of the present disclosure, there is provided a key generation method, comprising:

[0007] During fast roaming, the target AP obtains the STA air interface frame;

[0008] Calculate PMK_R1 based on the information in the air interface frame;

[0009] Calculate the random value RNonce based on PMK_R1;

[0010] The target AP returns the random value RNonce to the STA by replying an air interface frame.

[0011] In a possible implementation, after the target AP returns the random value RNonce to the STA via a reply air interface frame, the following steps are included:

[0012] After receiving the random value RNonce, the STA calculates the PTK using the random value RNonce and the STA's own SNonce;

[0013] The STA re-associates with the target AP through the PTK.

[0014] In a possible implementation, it includes:

[0015] The information in the air interface frame includes SSID, MDID, R0KH_ID and S0KH_ID. SSID is the service set identifier; MDID is the Mesh distributed identifier; R0KH_ID is the PMK-R0 key management entity identifier of the target AP side; S0KH_ID is the PMK-S0 key management entity identifier of the STA side.

[0016] In a possible implementation, calculating PMK_R1 according to information in the air interface frame includes:

[0017] Calculate SSIDlength based on the length of the SSID string, where SSIDlength is the length of the SSID;

[0018] Calculate R0KHlength based on the length of the R0KH_ID string, where R0KHlength is the length of R0KH_ID;

[0019] Calculate PMK_R0 based on SSIDlength, SSID, MDID, R0KHlength, R0KH_ID, S0KH_ID;

[0020] PMK_R1 is then calculated based on PMK_R0 and R1KH_ID and R0KH_ID in the air interface frame.

[0021] In a possible implementation, the calculation formula of PMK_R0 is:

[0022] R0_Key_Data=KDF_384(XXXKey,"FT_R1",SSIDlength||SSID

[0023] ||MDID||R0KHlength||R0KH_ID||S0KH_ID)

[0024] PMK_R0=L(R0_Key_Data,0,256);

[0025] Where, R0_Key_Data represents R0 key data; KDF_384 represents a key derivation function using 384-bit output; XXXKey represents a pre-shared key; "FT_R1" represents an identifier, which is a fixed value; PMK_R0 represents the pairwise master key R0; L(R0_Key_Data,0,256) means taking 256 bits starting from the 0th bit of R0_Key_Data as the value of PMK_R0.

[0026] In a possible implementation, the calculation formula of PMK_R1 is:

[0027] PMK_R1=KDF_256(PMK_R0,"FT_R1","R1KH_ID"||"R0KH_ID");

[0028] Where PMK_R1 represents the pairwise master key R1; KDF_256 represents the key derivation function using 256-bit output; R1KH_ID represents the PMK-R1 key management entity identifier of the target AP.

[0029] According to one aspect of the present disclosure, there is provided a key generation system, comprising:

[0030] The target AP is used to obtain STA air interface frames during fast roaming.

[0031] Calculate PMK_R1 based on the information in the air interface frame;

[0032] Calculate the random value RNonce based on PMK_R1;

[0033] The target AP returns the random value RNonce to the STA by replying an air interface frame.

[0034] In a possible implementation, the key generation system further includes:

[0035] STA, after receiving the random value RNonce, uses the random value RNonce and the STA's own SNonce to calculate the PTK;

[0036] The re-association unit is used to complete the re-association between the STA and the target AP through the PTK.

[0037] The present disclosure has the following beneficial effects: the present disclosure designs a method for locally generating keys based on 802.11r, and the distribution of PMK R1 can be locally calculated through information such as PMK-R0, R1KH_ID, and R0KH_ID, without the need to distribute the PMK R1 key through Ethernet frames, so that wireless network devices produced by different manufacturers can use the 802.11r fast roaming protocol for seamless connection and communication.

[0038] The details of one or more embodiments of the present application are presented in the following drawings and descriptions. Other features and advantages of the present application will become apparent from the accompanying drawings. It should be understood that the above general description and the detailed descriptions below are only exemplary and explanatory and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0040] Figure 1 It is a schematic diagram of the key distribution process in the prior art;

[0041] Figure 2 is a flow chart of a key generation method of the present exemplary embodiment;

[0042] Figure 3 is a local key calculation flow chart of this exemplary embodiment;

[0043] Figure 4 is a schematic diagram of fast switching Over-the-Air of this exemplary embodiment;

[0044] Figure 5 is a schematic diagram of fast switching Over-the-DS of this exemplary embodiment;

[0045] Figure 6 is a block diagram of a key generation system of the present exemplary embodiment;

[0046] Figure 7 It is a schematic structural diagram of a device of this exemplary embodiment. DETAILED DESCRIPTION

[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as being limited to the examples set forth herein; on the contrary, these embodiments are provided so that the present disclosure will be more comprehensive and complete, and the concepts of the example embodiments are fully conveyed to those skilled in the art. The described features, structures, or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or other methods, components, devices, steps, etc. may be adopted. In other cases, known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0048] In addition, the same reference numerals in the drawings represent the same or similar parts, and thus their repeated description will be omitted. Some of the block diagrams shown in the drawings are functional entities, which do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware units or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0049] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the steps. For example, some steps may be decomposed, while some steps may be combined or partially combined, so the actual execution order may change according to the actual situation.

[0050] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0051] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or sub-modules is not necessarily limited to those steps or sub-modules explicitly listed, but may include other steps or sub-modules not explicitly listed or inherent to these processes, methods, products, or apparatuses.

[0052] Figure 2 is a flowchart of a key generation method of this exemplary embodiment. Figure 2 As shown, an exemplary embodiment of the present disclosure provides a key generation method, comprising:

[0053] During fast roaming, the target AP obtains the STA air interface frame;

[0054] Calculate PMK_R1 based on the information in the air interface frame;

[0055] Calculate the random value RNonce based on PMK_R1;

[0056] The target AP returns the random value RNonce to the STA by replying an air interface frame.

[0057] Specifically, during fast roaming, the STA (Station, terminal) converts the air interface frame (i.e. Figure 4 Authentication Request in the packet is sent to the target AP (Access Point).

[0058] After receiving the air interface frame, the target AP calculates PMK_R1 (Pairwise MasterKey_R1) according to the information in the air interface frame, and calculates the random value RNonce (Reassociation Nonce) according to PMK_R1;

[0059] The target AP returns the random value RNonce to the STA via a reply air interface frame;

[0060] After receiving the random value RNonce, STA uses the random value RNonce and STA's own SNonce (server random number) to calculate PTK (Pairwise Transient Key).

[0061] The STA re-associates with the target AP through the PTK.

[0062] This embodiment designs a method for locally generating keys based on 802.11r. PMK R1 can be locally calculated through information such as PMK_R0 (Pairwise Master Key_R0), R1KH_ID, and R0KH_ID, and distributed through air interface frames. There is no need to distribute PMK_R1 keys through Ethernet frames. 11r intercommunication between different chips can be achieved, roaming delay can be reduced, and the device can roam more efficiently and quickly.

[0063] Fast BSS Transition (FBT) can be divided into two modes: Over-the-Air and Over-the-DS according to the different switching methods. Over-the-Air means that STA communicates directly with the target AP (target AP); Over-the-DS means that STA communicates with the target AP through the current AP (current AP).

[0064] Specifically, during the fast roaming process, the STA sends an air interface frame to the target AP including:

[0065] In Over-the-Air mode:

[0066] STA sends an air interface frame to the target AP. The RSNIE (Robust Security Network Information Element) in the air interface frame contains PMKR0_Name (Pairwise Master Key R0_Name), and the FTIE (Fast BSS Transition Information Element) contains SNonce (server random number), R0KH_ID (PMK-R0 key management entity identifier on the target AP side) and MDIE (key deployment information element).

[0067] like Figure 4 ( Figure 4 In the figure, Associated with current AP indicates association with the current AP; FTAA stands for Fast Terminal Authentication Algorithm, which refers to the fast terminal authentication algorithm; FTIE stands for Fast Terminal Integrity Evaluation, which refers to the fast terminal integrity evaluation; RIC stands for Radio Identity Code, which refers to the radio identity code). In this embodiment, in the Over-the-Air mode, the distributed fast switching authentication process based on local key generation is as follows:

[0068] During fast roaming, the STA sends an air interface frame to the AP. The RSNIE in the air interface frame includes PMKR0_Name, and the FTIE includes SNonce, R0KH_ID, and MDIE. The verification algorithm of the air interface frame is FT (Fast Transition).

[0069] Specifically, after receiving the air interface frame, the target AP calculates PMK_R1 according to the information in the air interface frame, including:

[0070] After receiving the air interface frame, the target AP calculates PMK_R0 based on the SSID (service set identifier), MDID, R0KH_ID, and STA MAC address related information in the air interface frame;

[0071] PMK_R1 is then calculated based on PMK_R0 and R1KH_ID and R0KH_ID in the air interface frame.

[0072] Specifically, completing the reassociation between the STA and the target AP through the PTK includes:

[0073] STA sends a Reassociation Request frame to the target AP. The Reassociation Request frame contains PMKR1Name, Anonce (AP random number), Snonce, MIC (Message Integrity Check) value, R1KH_ID and R0KH_ID;

[0074] After receiving the Reassociation Request frame, the target AP verifies the correctness of the Reassociation Request frame;

[0075] If the verification is successful, a Reassociation Response frame is sent to the STA, and the Reassociation Response frame contains the encrypted GTK (Group Temporal Key).

[0076] STA uses PTK to decrypt and obtain GTK, completing the reassociation between STA and target AP;

[0077] After the reassociation is completed, the 802.1X controlled port is opened and the STA can use the network normally.

[0078] Specifically, the calculation formula of PMK_R0 is:

[0079] R0_Key_Data=KDF_384(XXXKey,"FT_R1",SSIDlength||SSID

[0080] ||MDID||R0KHlength||R0KH_ID||S0KH_ID)

[0081] PMK_R0=L(R0_Key_Data,0,256);

[0082] Where, R0_Key_Data represents R0 key data; KDF_384 represents a key derivation function using 384-bit output; XXXKey represents a pre-shared key; "FT_R1" represents an identifier; SSIDlength is the length of the SSID; SSID is the service set identifier; MDID is the Mesh distributed identifier; R0KHlength is the length of R0KH_ID; R0KH_ID is the R0 key holder identifier; S0KH_ID is the S0 key holder identifier; PMK_R0 represents the pairwise master key R0; L(R0_Key_Data,0,256) means taking 256 bits starting from the 0th bit of R0_Key_Data as the value of PMK_R0.

[0083] like Figure 3 As shown, (Wtp is Wireless Termination Point, wireless access point) Specifically, the calculation formula of PMK_R1 is:

[0084] PMK_R1=KDF_256(PMK_R0,"FT_R1","R1KH_ID"||"R0KH_ID");

[0085] Where PMK_R1 represents the pairwise master key R1; KDF_256 represents the key derivation function using 256-bit output; R1KH_ID represents the R1 key holder identifier.

[0086] In this embodiment, a new random value RNonce is calculated by PMK_R1, and a new PTK is generated by using this random number and the previous PMKR1. The AP returns RNonce to the STA via an Authentication Response frame.

[0087] After receiving RNonce, STA uses its own SNonce and RNonce to calculate a new PTK. STA sends a Reassociation Request to the target AP, which contains PMKR1Name, Anonce, Snonce, MIC value, R1KH-ID and R0KH-ID.

[0088] The target AP receives the reassociation air interface frame and verifies its correctness. If the verification is successful, it replies with a ReassociationResponse frame to the STA, which contains the encrypted GTK. The STA uses the PTK to decrypt and obtain the GTK. After the reassociation is completed, the 802.1X controlled port is opened and the STA can use the network normally.

[0089] Specifically, during the fast roaming process, the STA sends an air interface frame to the target AP including:

[0090] In Over-the-DS mode:

[0091] STA sends a FT Request (Fast BSS Transition Request) containing the target AP MAC address to the current AP;

[0092] The current AP forwards the FT Request frame to the target AP via wired transmission;

[0093] After receiving the FT Request frame, the target AP identifies the forwarding source and replies with an FT Request frame, which is forwarded to the STA through the current AP.

[0094] like Figure 5 As shown in the figure, in Over-the-DS mode, the reassociation process is similar to Over-the-Air, with only the first two steps being different: STA first sends an FT Request frame containing the target AP MAC address to the current AP, and the current AP forwards the frame to the target AP via wired transmission. Specifically, after receiving the FT Request frame from the STA, the current AP recognizes that its target address is not its own, so it encapsulates the frame in a frame with Ethernet type 0x890d, attaches its own address, and forwards it to the target AP via Ethernet. After receiving it, the target AP identifies the forwarding source and replies with the corresponding FT Request frame, which is finally forwarded to the STA via the current AP.

[0095] Figure 6 is a block diagram of a key generation system of the present exemplary embodiment. Figure 6 As shown, an exemplary embodiment of the present disclosure provides a key generation system, comprising:

[0096] The target AP is used to obtain STA air interface frames during fast roaming.

[0097] Calculate PMK_R1 based on the information in the air interface frame;

[0098] Calculate the random value RNonce based on PMK_R1;

[0099] The target AP returns the random value RNonce to the STA by replying an air interface frame.

[0100] Specifically, the key generation system further includes:

[0101] STA, after receiving the random value RNonce, uses the random value RNonce and the STA's own SNonce to calculate the PTK;

[0102] The re-association unit is used to complete the re-association between the STA and the target AP through the PTK.

[0103] Figure 7 Schematic diagram of the structure of a device of this exemplary embodiment. Figure 7 As shown, corresponding to the key generation method provided above, the present disclosure also provides a device. Since the embodiment of the device is similar to the above method embodiment, the description is relatively simple. For relevant parts, please refer to the description of the above method embodiment part. The device described below is only schematic. The device may include: a processor (processor) 1, a memory (memory) 2 and a communication bus (i.e., the above device bus) and a search engine, wherein the processor 1 and the memory 2 communicate with each other through the communication bus and communicate with the outside through the communication interface. The processor 1 can call the logic instructions in the memory 2 to execute the key generation method.

[0104] In addition, the logic instructions in the above-mentioned memory 2 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present disclosure is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present disclosure. The aforementioned storage medium includes: a storage chip, a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and other media that can store program codes.

[0105] On the other hand, an embodiment of the present disclosure further provides a processor-readable storage medium, on which a computer program 3 is stored. When the computer program 3 is executed by the processor 1, the key generation method provided in the above embodiments is implemented.

[0106] The processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor 1, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NANDFLASH), solid-state drive (SSD)), etc.

[0107] The above are only preferred implementations of the present disclosure, and the protection scope of the present disclosure is not limited to the above embodiments. All technical solutions under the concept of the present disclosure belong to the protection scope of the present disclosure. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present disclosure should be regarded as the protection scope of the present disclosure.

Claims

1. A key generation method, characterized in that: include: During fast roaming, the target AP obtains the STA air interface frame; Calculate PMK_R1 based on the information in the air interface frame; Calculate the random value RNonce based on PMK_R1; The target AP returns the random value RNonce to the STA by replying an air interface frame.

2. The key generation method according to claim 1, characterized in that: The target AP returns the random value RNonce to the STA through the reply air interface frame, including: After receiving the random value RNonce, the STA calculates the PTK using the random value RNonce and the STA's own SNonce; The STA re-associates with the target AP through the PTK.

3. The key generation method according to claim 1, characterized in that: include: The information in the air interface frame includes SSID, MDID, R0KH_ID and S0KH_ID. SSID is the service set identifier; MDID is the Mesh distributed identifier; R0KH_ID is the PMK-R0 key management entity identifier of the target AP side; S0KH_ID is the PMK-S0 key management entity identifier of the STA side.

4. The key generation method according to claim 3, characterized in that: Calculating PMK_R1 based on the information in the air interface frame includes: Calculate SSIDlength based on the length of the SSID string, where SSIDlength is the length of the SSID; Calculate R0KHlength based on the length of the R0KH_ID string, where R0KHlength is the length of R0KH_ID; Calculate PMK_R0 based on SSIDlength, SSID, MDID, R0KHlength, R0KH_ID, S0KH_ID; PMK_R1 is then calculated based on PMK_R0 and R1KH_ID and R0KH_ID in the air interface frame.

5. The key generation method according to claim 4, characterized in that: The calculation formula of PMK_R0 is: R0_Key_Data=KDF_384(XXXKey,"FT_R1",SSIDlength||SSID ||MDID||R0KHlength||R0KH_ID||S0KH_ID) PMK_R0=L(R0_Key_Data,0,256); Where, R0_Key_Data represents R0 key data; KDF_384 represents a key derivation function using 384-bit output; XXXKey represents a pre-shared key; "FT_R1" represents an identifier, which is a fixed value; PMK_R0 represents the pairwise master key R0; L(R0_Key_Data,0,256) means taking 256 bits starting from the 0th bit of R0_Key_Data as the value of PMK_R0.

6. The key generation method according to claim 5, characterized in that: The calculation formula of PMK_R1 is: PMK_R1=KDF_256(PMK_R0,"FT_R1","R1KH_ID"||"R0KH_ID"); Where PMK_R1 represents the pairwise master key R1; KDF_256 represents the key derivation function using 256-bit output; R1KH_ID represents the PMK-R1 key management entity identifier of the target AP.

7. A key generation system, characterized in that: include: The target AP is used to obtain STA air interface frames during fast roaming. Calculate PMK_R1 based on the information in the air interface frame; Calculate the random value RNonce based on PMK_R1; The target AP returns the random value RNonce to the STA by replying an air interface frame.

8. The key generation system according to claim 7, characterized in that: Also includes: STA, after receiving the random value RNonce, uses the random value RNonce and the STA's own SNonce to calculate the PTK; The re-association unit is used to complete the re-association between the STA and the target AP through the PTK.

9. A device, characterized in that: include: Processor and memory; The memory is used to store a computer program, and the processor calls the computer program stored in the memory to execute the key generation method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor is enabled to execute the key generation method according to any one of claims 1 to 6.

Images