A data monitoring method, system, medium and computer device

Abstract

The application discloses a data monitoring method and system, a medium and a computer device. The method comprises the following steps: capturing handshake information generated when a server and a client negotiate based on a target protocol; analyzing the transmission format of the handshake information, and extracting an encryption suite, a session key and a random number used for data transmission encryption; the encryption suite comprises one or more encryption algorithms; dynamically selecting an encryption algorithm from the encryption suite, processing the session key and the random number by using the encryption algorithm, and generating a decryption key; capturing encrypted data packets transmitted by the server and the client based on the target protocol; and decrypting the encrypted data packets by using the decryption key, and generating data plaintext used for security analysis.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of network security, and in particular to a data monitoring method, system, medium and computer device. BACKGROUND

[0002] With the acceleration of the global digitalization process, the Internet has become the main platform for information transmission and exchange. Under this background, information security problems are becoming increasingly prominent, especially involving the transmission of sensitive data.

[0003] In order to ensure the confidentiality, integrity and identity authentication of both parties of the information, TLS (Transport Layer Security, Transport Layer Security Protocol) has been widely used. In particular, the TLS 1.3 protocol, because it simplifies the handshake process of the protocol, improves the speed of connection establishment, and increases the support for Perfect Forward Secrecy (PFS). This makes the TLS 1.3 protocol one of the most secure transport layer protocols to date.

[0004] At present, in order to discover abnormal network communication activities, data security monitoring of TLS 1.3 protocol communication is needed, and the core of data security monitoring is the management and use of session keys. The existing technology generally relies on KDF (Key Derivation Function, Key Derivation Function based on Hash Function) to generate session keys, and adopts stream cipher or block cipher to process ciphertext in the decryption process to realize the supervision of TLS 1.3 protocol communication. However, the KDF algorithm is too complex and cannot be flexibly adapted to various different hardware environments and network conditions, thereby increasing the difficulty of data security monitoring, and the supervision efficiency of data security monitoring is also reduced. SUMMARY

[0005] In order to solve or partially solve the technical problem that the existing technology cannot flexibly adapt to various different hardware environments and network conditions, thereby reducing the supervision efficiency of data security monitoring, the present application provides a data monitoring method, system, medium and computer device. By optimizing the processing of the handshake message and adopting the dynamic selection mechanism of the encryption algorithm, it is ensured that the decryption key can be efficiently derived under different hardware environments and network conditions, the optimal decryption performance and security can be obtained, and the efficiency of data security monitoring can be effectively improved and the adaptability of the supervision system can be enhanced.

[0006] To solve the above technical problems, the first aspect of the present application discloses a data monitoring method, the method comprising:

[0007] Capturing handshake information generated when a server and a client negotiate based on a target protocol handshake;

[0008] parsing a transmission format of the handshake information to extract an encryption suite, a session key and a random number used for data transmission encryption, wherein the encryption suite contains one or more encryption algorithms;

[0009] dynamically selecting an encryption algorithm from the encryption suite and processing the session key and the random number by using the encryption algorithm to generate a decryption key;

[0010] capturing the encrypted data packets transmitted by the server and the client based on the target protocol;

[0011] decrypting the encrypted data packets by using the decryption key to generate data plaintext for security analysis.

[0012] Optionally, the handshake information generated by the server and the client during handshake negotiation based on the target protocol specifically includes:

[0013] real-time monitoring a handshake negotiation process of the server and the client based on the target protocol and capturing the handshake information generated during the handshake negotiation process by using a handshake capturing tool.

[0014] Optionally, the parsing of the transmission format of the handshake information to extract the encryption suite, the session key and the random number used for data transmission encryption specifically includes:

[0015] parsing a transmission format of the handshake information to extract the encryption suite and a shared key;

[0016] referencing the shared key to obtain the corresponding session key and the random number.

[0017] Optionally,

[0018] The referencing of the shared key to obtain the corresponding session key and the random number specifically includes:

[0019] generating a key derivation request for calling the key derivation function based on the hash message authentication code based on the shared key;

[0020] checking whether the corresponding session key and the random number exist in a cache based on the key derivation request;

[0021] if yes, directly calling the session key and the random number;

[0022] if no, deriving the session key and the random number from the shared key by using the key derivation function based on the hash message authentication code and storing the derived session key and the random number in the cache.

[0023] Optionally, the storing the derived session key and the random number into the cache comprises:

[0024] Based on the key derivation request, an identity identifier for searching the session key and the random number is generated; wherein the identity identifier is used as a cache key;

[0025] The session key and the random number are stored in a cache area corresponding to the cache key.

[0026] Optionally, the capturing the encrypted data packet based on the target protocol transmission comprises:

[0027] Intercepting a plurality of fragmented traffics from a designated network interface of the server or the client; the fragmented traffics carry one or more identity information of TCP sequence number, IP address and port number;

[0028] According to the identity information carried by each of the plurality of fragmented traffics, the plurality of fragmented traffics are assembled into the encrypted data packet.

[0029] Optionally, the encryption algorithm at least includes AES-GCM encryption algorithm and ChaCha20-Poly1305 encryption algorithm.

[0030] The second aspect of the application discloses a data monitoring system, comprising:

[0031] A first capturing module is configured to capture handshake information generated when a server and a client negotiate based on a target protocol;

[0032] A key parameter derivation module is configured to analyze a transmission format of the handshake information, and extract an encryption suite, a session key and a random number used for data transmission encryption; wherein the encryption suite comprises one or more encryption algorithms;

[0033] A key generation module is configured to dynamically select an encryption algorithm from the encryption suite, and process the session key and the random number by using the encryption algorithm to generate a decryption key;

[0034] A second capturing module is configured to capture the encrypted data packet transmitted by the server and the client based on the target protocol;

[0035] A decryption module is configured to decrypt the encrypted data packet by using the decryption key to generate data plaintext for security analysis.

[0036] The third aspect of the application discloses a computer readable storage medium, which stores a computer program; when the program is executed by a processor, the steps of the above method are realized.

[0037] In a fourth aspect, the present application provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method when executing the program.

[0038] The present application has the following advantages and benefits:

[0039] The present application provides a data monitoring method and system, a medium and a computer device. The handshake information generated when a server and a client negotiate based on a target protocol is captured. The transmission format of the handshake information is analyzed to quickly extract an encryption suite, a session key and a random number used for data transmission encryption. Different encryption algorithms are dynamically selected from the encryption suite to adapt to network requirements, and corresponding decryption keys are generated to decrypt data plaintext used for security analysis, so that decryption keys can be efficiently derived under different hardware environments and network conditions, optimal decryption performance and security can be obtained, and the efficiency of data security monitoring and the adaptability of the monitoring system can be improved.

[0040] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the content of the specification can be implemented, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described below. BRIEF DESCRIPTION OF DRAWINGS

[0041] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Furthermore, the same reference numerals are used throughout the several views that follow. In the drawings:

[0042] Figure 1 An implementation flowchart of a data monitoring method according to an embodiment of the present application is shown;

[0043] Figure 2 A module schematic diagram of a data monitoring system according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0044] Exemplary embodiments of the present application will be described below in greater detail with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be accurately conveyed to those skilled in the art.

[0045] Exemplary embodiments of the present application will be described in greater detail below, with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms without being limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0046] In a first aspect, as Figure 1 The data monitoring method provided by the embodiments of the present application at least includes the following steps:

[0047] Step 101, capturing the handshake information generated by the server and the client during handshake negotiation based on the target protocol.

[0048] In this embodiment, the target protocol at least includes the TLS 1.3 protocol. The server and the client perform handshake negotiation based on the TLS 1.3 protocol to establish a secure communication channel and generate necessary keys for subsequent encrypted communication.

[0049] Considering that the extraction of the handshake message is the basis for data decryption, in order to monitor the communication between the server and the client, the handshake information generated by the server and the client during handshake negotiation is first captured. The captured handshake messages include but are not limited to the following messages:

[0050] ClientHello: The first handshake message sent by the client to the server, which contains the encryption algorithms supported by the client, the protocol version, the random number and other options.

[0051] ServerHello: The server responds to the client's handshake message, confirms the encryption algorithm used, session information and the server's random number.

[0052] Cipher Suite: The cipher suite is a combination of several groups of encryption algorithms defined in the TLS 1.3 protocol, which is used to ensure the security of data transmission. The cipher suite contains one or more encryption algorithms. Specifically, the cipher suite mainly includes various algorithms for key exchange, data encryption and message authentication. They are negotiated during the handshake of the TLS 1.3 protocol to determine which algorithms will be used by both parties. For example, ECDHE (Ephemeral Elliptic Curve Diffie-Hellman, ephemeral elliptic curve Diffie-Hellman key exchange algorithm) is negotiated for key exchange.

[0053] Key Exchange message: used to negotiate a shared key between two communicating parties over an open channel without pre-sharing any secret information, which is used for subsequent encrypted communication to ensure data communication security. For example, ECDHE is used to negotiate a shared key between two communicating parties.

[0054] These handshake messages are transmitted in a specific order over a TCP connection. In the protocol stack, the handshake messages are located above the TLS record layer, and the start of the message is identified by the handshake message type (0x16), followed by the handshake content.

[0055] During the capture process, the handshake negotiation process of the server and the client based on the target protocol is monitored in real time, and the handshake information generated during the handshake negotiation process is captured using a handshake capture tool. An example of a handshake capture tool is gopacket, a network packet capture tool, which is used to capture handshake messages based on the TLS 1.3 protocol. When the client sends a "ClientHello" message, the server responds with a "ServerHello" message, and various encryption algorithms in the encryption suite, etc. are captured and stored for subsequent use.

[0056] Step 102: Analyze the transmission format of the handshake information to extract the encryption suite, session key, and random number used for data transmission encryption.

[0057] During the analysis process, it is considered that the handshake information is stored in a set transmission format, such as the TLV (Type-Length-Value) transmission format. Therefore, the transmission format of the handshake information is analyzed to extract the encryption suite and shared key used for data transmission encryption. Specifically, the message type, length, and content of the handshake message are parsed, and the encryption suite and shared key are extracted. The shared key can be used as input key material for HKDF (Hash-based Key Derivation Function), which can derive the session key and random number used for encryption and decryption. Therefore, by referring to the shared key, the corresponding session key and random number are obtained.

[0058] In a specific implementation process, if multiple sessions reuse the same handshake information, or multiple key derivation operations are required within a short period of time, a large amount of redundant calculation will be caused. This will increase the calculation load and cause decryption delay. It is important to reduce repeated calculation and utilize cache to improve performance. Therefore, the embodiment introduces a cache mechanism, that is, when key derivation is performed, the calculated key result is stored, so that the cached key is directly used under the same input condition in the subsequent process, instead of re-performing key calculation. In this way, repeated key derivation operations can be avoided, especially in the case of high concurrency and multiple sessions. This optimization can significantly reduce the calculation load and improve decryption speed.

[0059] Therefore, the specific operation of the embodiment is as follows:

[0060] Step 1021, based on the shared key, a key derivation request calling the hash-based message authentication code-based key derivation function is generated. For example, a key derivation request calling the HKDF-Extract function or the HKDF-Expand function is generated.

[0061] Step 1022, based on the key derivation request, it is checked whether the corresponding session key and random number exist in the cache. If the session key and the random number exist in the cache, step 1023 is performed.

[0062] Specifically, when the key derivation request triggers the calling of the HKDF-Extract function or the HKDF-Expand function, it can trigger the checking of whether the corresponding cache result already exists in the cache. For example, it is checked whether the shared key, the random number, the context, etc. exist in the cache. If they exist, step 1023 is performed. Further, if the key derivation request has a cache key, it can be used to check whether the corresponding session key and random number exist in the cache. If they exist, step 1023 is performed.

[0063] Step 1023, the session key and the random number are directly called.

[0064] If the session key and the random number do not exist in the cache, step 1024 is performed.

[0065] Step 1024, the hash-based message authentication code-based key derivation function HKDF is called to derive the shared key, to obtain the session key and the random number, and the derived session key and random number are stored in the cache.

[0066] The process of deriving the session key and the random number by using the HKDF function is as follows:

[0067] (1) Create Early Secret: When the handshake is detected, the Early Secret is extracted from the zero value (0x00) and the pre-shared key (PSK) to be used for the initial session key exchange and early data encryption, such as the encryption of 0-RTT data. The execution logic is: early_secret = HKDF-Extract(0, PSK).

[0068] (2) Generate Derive Secret.

[0069] The execution logic of the Derive Secret is: derive_secret = Derive-Secret(early_secret, "derived", "").

[0070] (3) Generate Handshake Secret: After the key exchange is completed, the client and server use the Diffie-Hellman algorithm to calculate the shared key, also known as the handshake key, which is used to generate encryption keys and authentication keys used in the handshake process.

[0071] The execution logic of the shared key is: handshake_secret = HKDF-Extract(dhe, derive_secret).

[0072] (4) Expand Derive Secret from shared key:

[0073] derive_secret = Derive-Secret(handshake_secret, "derived", "").

[0074] (5) Generate Master Secret: Expand the Master Secret from the shared key, which is the core key used to generate multiple session keys for decrypting data at different stages. The execution logic of the master key is: master_secret = HKDF-Extract(0, derive_secret).

[0075] (6) Calculate the session key Key and random number IV from the master key Master Secret.

[0076] First, based on the master key, an intermediate variable for processing captured traffic is generated by a specific derivation function (Derive-Secret) in combination with the label "captraffic" and hash messages, and then a session key Key and a random number IV are derived based on the intermediate variable using the HKDF algorithm.

[0077] captraffic:=Derive-Secret(master_secret,“cap traffic”,hash_messages)

[0078] Key=HKDF-Extract(captraffic,`key`,32).

[0079] IV(Initialization Vector, counter)=HKDF-Extrac(captraffic,`iv`,12). The counter is a component of the decryption of encrypted data packets, ensuring that each encrypted data packet uses a different decryption key, avoiding key reuse, even if these encrypted data packets are in the same session, and each can obtain the corresponding decryption key according to the counter.

[0080] After key derivation, a cache mechanism can also be introduced. In order to distinguish different key derivation requests, an identity identifier for searching the session key and the random number is generated based on the key derivation request; wherein the identity identifier is used as a cache key; the session key and the random number are stored in the cache area corresponding to the cache key. The identity identifier is a unique identifier of the session key and the random number, which has a mapping relationship with the hash of the handshake message, the session ID, the random number and other parameters. Therefore, when the same key derivation request comes, the corresponding cache result can be quickly found according to the cache key.

[0081] In an optional embodiment, in order to avoid excessive memory or storage space occupied by the cache, expired keys in the cache are cleaned up regularly. For example, according to the life cycle of the session, the validity period of the key and other strategies to decide to clean up the cache.

[0082] In the technical solution, a lightweight key derivation algorithm HKDF is introduced to replace the traditional KDF key derivation function, which can greatly reduce the computational complexity while maintaining security.

[0083] Step 103, dynamically selecting an encryption algorithm from the encryption suite, and processing the session key and the random number using the encryption algorithm to generate a decryption key.

[0084] In the embodiment, in order to ensure optimal decryption performance and security under different hardware environments and network conditions, a dynamic selection mechanism is followed to dynamically select an encryption algorithm from the encryption suite to efficiently decrypt the ciphertext.

[0085] The encryption suite defines the encryption algorithm, key exchange algorithm and hash algorithm used in the TLS 1.3 protocol. In the decryption process, the AEAD (Authenticated Encryption with Associated Data) encryption mode is followed, and therefore, the AES-GCM encryption algorithm and the ChaCha20-Poly1305 encryption algorithm are simultaneously supported, the decryption efficiency is improved through the dynamic algorithm selection mechanism, and the security and performance requirements in specific scenarios are met.

[0086] In the process of generating the key, the selected encryption algorithm (for example, the AES-GCM encryption algorithm or the ChaCha20-Poly1305 encryption algorithm) is used to process the session key and the random number, and thus the unique decryption key of the encrypted data packet is generated.

[0087] Step 104, capturing the encrypted data packet transmitted by the server and the client based on the target protocol.

[0088] Specifically, the encrypted data packet is intercepted from a specified network interface of the server or the client, for example, the libpcap (a capture tool) is used to capture the encrypted data packet passing through the network interface, but this does not form a limitation.

[0089] In the HTTPS request process, the encrypted data packet may be transmitted in fragments, and needs to be reassembled. Specifically, a plurality of fragmented flows are intercepted from a specified network interface of the server or the client; the fragmented flows carry one or more identity information of a TCP sequence number, an IP address and a port number; and the plurality of fragmented flows are assembled into the encrypted data packet according to the identity information carried by each of the plurality of fragmented flows.

[0090] Step 105, decrypting the encrypted data packet by using the decryption key to generate data plaintext for security analysis.

[0091] Through the above steps, the data monitoring based on the TLS 1.3 protocol is realized, the key can be efficiently derived from the handshake message, the efficiency of data security monitoring is effectively improved, and the adaptability of the system is enhanced.

[0092] The application ensures optimal decryption performance and security in different hardware environments and network conditions through an intelligent key cache and a dynamic algorithm selection mechanism, improves the flexibility of decryption algorithms, reduces the consumption of system resources, and is suitable for a wide range of application scenarios from high-performance servers to resource-constrained devices.

[0093] In a second aspect, based on the same inventive concept as the data monitoring method provided in the first aspect, the application also provides a data monitoring system, which refers to Figure 2 , comprising:

[0094] A first capture module 201 is configured to capture handshake information generated when a server and a client negotiate based on a target protocol;

[0095] A key parameter derivation module 202 is configured to parse the transmission format of the handshake information, extract an encryption suite, a session key, and a random number used for data transmission encryption, and wherein the encryption suite contains one or more encryption algorithms;

[0096] A key generation module 203 is configured to dynamically select an encryption algorithm from the encryption suite, and process the session key and the random number using the encryption algorithm to generate a decryption key;

[0097] A second capture module 204 is configured to capture the encrypted data packets transmitted by the server and the client based on the target protocol;

[0098] A decryption module 205 is configured to decrypt the encrypted data packets using the decryption key to generate data plaintext for security analysis.

[0099] It should be noted that the data monitoring system provided in the embodiments of the application, wherein the specific manner in which each module performs operations has been described in detail in the method embodiments provided in the first aspect, and the specific implementation process can be referred to the method embodiments provided in the first aspect, which will not be described in detail here.

[0100] In a third aspect, based on the same inventive concept as the data monitoring method provided in the first aspect, the application also discloses a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the steps of any of the methods described above.

[0101] In a fourth aspect, based on the same inventive concept as the data monitoring method provided in the first aspect, the application also discloses a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the program to implement the steps of any of the methods described above.

[0102] Through one or more embodiments of the present application, the present application has the following beneficial effects or advantages:

[0103] The present application provides a data monitoring method, system, medium and computer device, first capture the handshake information generated when the server and the client negotiate based on the target protocol handshake; then analyze the transmission format of the handshake information, thereby quickly extracting the encryption suite, session key and random number used for data transmission encryption; for different hardware environments and network conditions, dynamically select the encryption algorithm from the encryption suite to flexibly adapt to the network demand, and generate the corresponding decryption key to decrypt the data plaintext used for security analysis, thereby ensuring that the decryption key can be derived efficiently under different hardware environments and network conditions, the optimal decryption performance and security can be obtained, the efficiency of data security monitoring can be effectively improved, and the adaptability of the supervision system is enhanced.

[0104] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the present application.

[0105] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A data monitoring method, characterized in that: The method comprises: Capturing handshake information generated by a server and a client during a handshake negotiation based on a target protocol, specifically comprising: monitoring the handshake negotiation process between the server and the client based on the target protocol in real time, and using a handshake capture tool to capture the handshake information generated during the handshake negotiation process; Parsing the transmission format of the handshake information to extract the encryption suite, session key, and random number used for data transmission encryption; wherein the encryption suite includes one or more encryption algorithms; Dynamically selecting an encryption algorithm from the encryption suite, and processing the session key and the random number using the encryption algorithm to generate a decryption key; Capturing the encrypted data packets transmitted by the server and the client based on the target protocol, specifically comprising: intercepting a plurality of fragmented flows from a designated network interface of the server or the client; the fragmented flows carrying one or more identity information of a TCP sequence number, an IP address, and a port number; and assembling the plurality of fragmented flows into the encrypted data packet according to the identity information carried by each of the plurality of fragmented flows; The encrypted data packet is decrypted using the decryption key to generate data plaintext for security analysis.

2. The method according to claim 1, wherein Parsing the transmission format of the handshake information to extract the encryption suite, session key, and random number used for data transmission encryption specifically includes: Parsing the transmission format of the handshake information to extract the encryption suite and shared key; The corresponding session key and the random number are obtained by referring to the shared key.

3. The method according to claim 2, wherein The obtaining the corresponding session key and the random number by referring to the shared key specifically includes: Based on the shared key, generating a key derivation request for invoking the key derivation function based on the hash message authentication code; Based on the key derivation request, checking whether the corresponding session key and random number exist in a cache; If yes, directly call the session key and the random number; If not, the key derivation function based on the hash message authentication code is called to derive the shared key to obtain the session key and the random number, and the derived session key and the random number are stored in the cache.

4. The method according to claim 3, wherein The step of storing the derived session key and the random number in the cache specifically includes: Based on the key derivation request, generating an identity identifier for searching the session key and the random number; wherein the identity identifier is used as a cache key; The session key and the random number are stored in a cache area corresponding to the cache key.

5. The method according to claim 1, wherein The encryption algorithm includes at least the AES-GCM encryption algorithm and the ChaCha20-Poly1305 encryption algorithm.

6. A data monitoring system, characterized in that: include: The first capture module is used to capture the handshake information generated by the server and the client during the handshake negotiation based on the target protocol; a key parameter derivation module, configured to parse the transmission format of the handshake information and extract the encryption suite, session key, and random number used for data transmission encryption; wherein the encryption suite includes one or more encryption algorithms; a key generation module, configured to dynamically select an encryption algorithm from the encryption suite, and process the session key and the random number using the encryption algorithm to generate a decryption key; a second capture module, configured to capture the encrypted data packets transmitted by the server and the client based on the target protocol, specifically comprising: intercepting a plurality of fragmented flows from a designated network interface of the server or the client, wherein the fragmented flows carry one or more identity information selected from the group consisting of a TCP sequence number, an IP address, and a port number; and assembling the plurality of fragmented flows into the encrypted data packet based on the identity information carried by each of the plurality of fragmented flows; The decryption module is used to decrypt the encrypted data packet using the decryption key to generate data plaintext for security analysis.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method according to any one of claims 1 to 5 are implemented.

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