WO2021017735A1

WO2021017735A1 - Smart contract formal verification method, electronic apparatus and storage medium

Info

Publication number: WO2021017735A1
Application number: PCT/CN2020/099478
Authority: WO
Inventors: 张驰; 厉鹏飞; 周永超
Original assignee: 平安科技（深圳）有限公司
Priority date: 2019-07-31
Filing date: 2020-06-30
Publication date: 2021-02-04
Also published as: CN110532176B; CN110532176A

Abstract

A smart contract formal verification method, an electronic apparatus and a storage medium, capable of compiling source code of a smart contract into an abstract syntax tree and performing disassembly of the smart contract source code, obtaining a target file containing assembly code of the smart contract (201), then converting information in the abstract syntax tree into the target file (202); on the basis of the assembly code and abstract syntax tree information in the target file, generating a formal verification rule statement adapted for a smart contract formal verification method (203), the abstract syntax tree information in the target file being capable of making up for deficiencies in the smart contract assembly code to a certain extent, making extraction of a formal verification rule statement more complete, and helping to improve formal verification accuracy and smart contract security.

Description

Formal verification method, electronic device and storage medium of smart contract

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on July 31, 2019, the application number is 201910699357.6, and the invention title is "a method for formal verification of smart contracts, electronic devices and storage media", all of which The content is incorporated in this application by reference.

Technical field

This application relates to the field of blockchain technology, and in particular to a formal verification method, electronic device and storage medium of a smart contract.

Background technique

For smart contract detection, the related technology is to directly extract formal verification rule statements from the assembly code of the smart contract, and then perform formal verification based on these rule statements.

However, when the smart contract is converted from source code to assembly code, the source code will be optimized and adjusted, so some logic in the source code, such as the information of the inherited parent class, will be missing. The inventor realizes that the formal verification of smart contracts based on assembly code may cause problems such as missing information and low verification accuracy, which will adversely affect the security of smart contracts.

Summary of the invention

The embodiments of the present application provide a formal verification method, an electronic device, and a storage medium for a smart contract, which help to improve the accuracy of the formal verification of the smart contract and help ensure the security of the smart contract.

The first aspect of the embodiments of the present application provides a formal verification method of a smart contract. The formal verification method of the smart contract includes:

Obtaining the source code of the smart contract to be verified, compiling the source code of the smart contract into an abstract syntax tree, and disassembling the source code of the smart contract to obtain a target file containing the assembly code of the smart contract;

Converting the information in the abstract syntax tree to the target file;

Acquiring a formal verification method corresponding to the smart contract, and generating formal verification rule statements suitable for the formal verification method based on the assembly code in the target file and the information of the abstract syntax tree in the target file;

Perform formal verification of the smart contract according to the generated rule statement.

A second aspect of the embodiments of the present application provides an electronic device, which includes:

The compilation module is used to obtain the source code of the smart contract to be verified, compile the source code of the smart contract into an abstract syntax tree, and disassemble the source code of the smart contract to obtain the assembly containing the smart contract The object file of the code;

A conversion module for converting the information in the abstract syntax tree to the target file;

The generation module is used to obtain the formal verification method corresponding to the smart contract, and generate a form suitable for the formal verification method based on the assembly code in the target file and the information of the abstract syntax tree in the target file Validation rule statement;

The verification module is used to perform formal verification of the smart contract according to the generated rule statement.

A third aspect of the embodiments of the present application provides an electronic device, the electronic device includes a memory and a processor, and the processor and the memory are connected to each other, wherein the memory is used to store a computer program, and the computer program Comprising program instructions, the processor is used to execute the program instructions of the memory, wherein:

Converting the information in the abstract syntax tree to the target file;

A fourth aspect of the embodiments of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program includes program instructions. When the program instructions are executed by a processor, they are used to implement the following step:

Converting the information in the abstract syntax tree to the target file;

The embodiment of the application discloses a formal verification method, an electronic device and a storage medium of a smart contract, which can obtain the source code of the smart contract to be verified, compile the source code of the smart contract into an abstract syntax tree, and perform the verification of the smart contract. Disassemble the source code to obtain the target file containing the assembly code of the smart contract, and convert the information in the abstract syntax tree to the target file; obtain the formal verification method corresponding to the smart contract, based on the assembly code and the target file in the target file In the above scheme, in the process of generating the abstract syntax tree, the variable names, method names, and logical relationships in the smart contract are as inherited The information of the parent class, etc., will be reflected in the abstract syntax tree, so the information of the abstract syntax tree in the target file can make up for the shortcomings of the assembly code of the smart contract to a certain extent. When generating the formal verification rule statement, In the case of missing information in some assembly codes, the missing information can be obtained from the information in the language abstract syntax tree, which is conducive to improving the accuracy of the formal verification of the smart contract and ensuring the security of the smart contract.

Description of the drawings

FIG. 1 is a schematic diagram of the hardware structure of an electronic device provided by this application;

2 is a schematic flow chart of the method for formal verification of smart contracts provided by the first embodiment of this application;

3 is a schematic diagram of the information of the abstract syntax tree after the information of the abstract syntax tree is transformed into the target file in the first embodiment of the application;

4 is a schematic structural diagram of an electronic device provided by a second embodiment of this application;

FIG. 5 is a schematic structural diagram of an electronic device provided by the third embodiment of this application.

Detailed ways

In order to make the purposes, features, and advantages of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the description The embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative work shall fall within the protection scope of this application.

Referring to Fig. 1, Fig. 1 shows a structural block diagram of an electronic device. The method for formal verification of smart contracts provided by the embodiments of the present application can be applied to the electronic device 10 shown in FIG. 1. The electronic device 10 includes but is not limited to: mobile terminals such as smart phones, notebooks, and wearable smart devices, as well as fixed Terminals such as desktop computers and smart TVs, etc.

As shown in FIG. 1, the electronic device 10 includes a memory 101, a storage controller 102, one or more (only one is shown in the figure) processor 103, a peripheral interface 104 and a touch screen 105. These components communicate with each other through one or more communication buses/signal lines 106.

It can be understood that the structure shown in FIG. 1 is only for illustration, and it does not limit the structure of the electronic device. The electronic device 10 may also include more or fewer components than shown in FIG. 1 or have a different configuration from that shown in FIG. 1. The components shown in Figure 1 can be implemented by hardware, software or a combination thereof.

The memory 101 can be used to store software programs and modules, such as the formal verification method of a smart contract and program instructions/modules corresponding to the electronic device in the embodiment of the present application. The processor 103 runs the software programs and modules stored in the memory 101, In order to perform various functional applications and data processing, for example, to implement the above-mentioned formal verification method for smart contracts.

The memory 101 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 101 may further include a memory remotely provided with respect to the processor 103, and these remote memories may be connected to the electronic device 10 via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The processor 103 and other possible components may access the memory 101 under the control of the memory controller 102.

The peripheral interface 104 couples various input/input devices to the CPU and the memory 101. The processor 103 runs various software and instructions in the memory 101 to perform various functions of the electronic device 10 and perform data processing.

In some embodiments, the peripheral interface 104, the processor 103, and the storage controller 102 may be implemented in a single chip. In some other instances, they can be implemented by independent chips.

The touch screen 105 simultaneously provides an output and input interface between the electronic device and the user. Specifically, the touch screen 105 displays video output to the user, and the content of the video output may include text, graphics, video, and any combination thereof. Some output results of the touch screen 105 correspond to some user interface objects. The touch screen 105 also receives input from the user, such as gesture operations such as clicking and sliding of the user, so that the user interface objects can respond to these user inputs. The technology for detecting user input may be based on resistive, capacitive or any other possible touch detection technology. Specific examples of the display unit of the touch screen 105 include, but are not limited to, a liquid crystal display or a light-emitting polymer display.

The formal verification method of the smart contract in the embodiment of the present application is described based on the above electronic device.

The first embodiment:

The embodiment of the application proposes a formal verification method for smart contracts, which can improve the quality of formal verification rule statements, and improve the accuracy of formal verification and the security of smart contracts.

Referring to Fig. 2, the formal verification method of the smart contract of this embodiment includes the following steps:

Step 201: Obtain the source code of the smart contract to be verified, compile the source code of the smart contract into an abstract syntax tree, and disassemble the source code of the smart contract to obtain a target file containing the assembly code of the smart contract;

The abstract syntax tree in this embodiment is a tree representation of the abstract syntax structure of the source code of the smart contract. The abstract syntax tree exists in the form of nodes and is nested layer by layer.

Optionally, compiling the source code of the smart contract into an abstract syntax tree includes: using a preset syntax analyzer to extract keywords or identifiers from the source code of the smart contract, and use each keyword or identifier as a smart contract A node in the abstract syntax tree; according to the position and order of the extracted keywords or identifiers, the hierarchical relationship of the nodes corresponding to the keywords or identifiers is divided, and all the nodes and the relationships between the nodes form the smart contract Abstract syntax tree.

Among them, after extracting the keywords or identifiers from the source code, it also includes: dividing the keywords or identifiers into different node types. The node types in this embodiment include but are not limited to contract (contract object), function (method object), param, value, return, and other node types.

In this embodiment, the hierarchical relationship of the nodes corresponding to the keywords or identifiers is divided according to the position and order in which the extracted keywords or identifiers appear. It can be understood that the extracted keywords or identifiers are in the source code of the smart contract. The position and order of appearance, the hierarchical relationship of the nodes corresponding to the keywords or identifiers.

In this embodiment, after the source code is compiled into an abstract syntax tree, the attributes and types of each node of the abstract syntax tree, as well as the relationship between the nodes and the source code information corresponding to the nodes, can be analyzed through the abstract syntax tree get.

In an example of this embodiment, the target file may be an xSol file.

Step 202: Convert the information in the abstract syntax tree to the target file;

In this embodiment, the process of converting the information in the abstract syntax tree to the target file can be understood as a process of copying the value of the abstract syntax tree by the target file. For example, the target file is an xSol file, and the process of converting the information in the abstract syntax tree to the target file is the process of copying the value of the abstract syntax tree by the xSol object.

Optionally, converting the information in the abstract syntax tree to the target file includes the following steps a and b:

Step a: Analyze the node type of each node in the abstract syntax tree;

Step b: Copy the information of the nodes in the abstract syntax tree to the target file according to the node type, where in the target file obtained after copying, the information of the nodes of the same type in the abstract syntax tree is located under the corresponding name of the same node type .

Among them, when analyzing the node type of each node of the abstract syntax tree, each node can also be divided according to the node type first. For example, divide nodes of contract type together, divide nodes of function type together, divide nodes of node type together, and so on.

For example, see FIG. 3, which shows the result of converting an abstract syntax tree to an xsol file when the target file is an xsol file. In Figure 3, the node type name of the contract object is the contract object in the abstract syntax tree, the function object is the function object in the abstract syntax tree, and the node type name is the node object. Listed below are the node objects in the abstract syntax tree.

Of course, it can be understood that the node types in FIG. 3 are only for illustration, and the number and names of the node types are not limited. In practice, other node types can also exist in the abstract syntax tree.

In this embodiment, based on the above copy, the target file contains not only the assembly code of the smart contract, but also the node information in the abstract syntax tree of the smart contract. The abstract syntax tree contains more information about inherited objects/interfaces than the assembly code. The information of inherited objects/interfaces is more comprehensive, which helps to extract more comprehensive formal verification rules, helps to improve the verification accuracy of the formal verification rules of smart contracts, discovers more vulnerabilities in smart contracts, and improves the security of smart contracts .

Step 203: Obtain a formal verification method corresponding to the smart contract, and generate formal verification rule statements suitable for the formal verification method based on the assembly code in the target file and the information of the abstract syntax tree in the target file;

Step 204: Perform formal verification of the smart contract according to the generated rule statement.

In this embodiment, based on the assembly code in the target file and the information of the abstract syntax tree in the target file, generating a formal verification rule statement suitable for the formal verification method includes steps c-e:

Step c. Obtain the security requirements of the smart contract, and based on the security requirements and the formal verification method, determine the formal verification rule statements suitable for the formal verification method to be generated;

Step d. Extract the information needed to generate formal verification rule statements from the information of the abstract syntax tree in the target file and the assembly code;

Step e: Based on all the extracted information and the formal verification method, a formal verification rule statement suitable for the formal verification method is generated.

Optionally, for this embodiment, the formal verification method can be selected according to actual needs, for example, the formal verification method of z3 is selected. When a formal verification rule statement is generated based on the information in the target file, a form that conforms to z3 is generated The rule statement of the verification framework.

In one example, the security requirements input by the user can be obtained in real time through some input device such as a microphone or a touch screen, and converted into a smart contract security requirement specification document described in non-natural language. Correspondingly, based on the security requirements and formal verification methods, the formal verification rule statements that need to be generated suitable for the formal verification method include: based on the smart contract security requirements specification document and the formal verification method, determine the appropriate form that needs to be generated Formal verification rule statement of the verification method.

In another example, a locally pre-stored smart contract security requirement specification file can be used.

Optionally, the security requirements specification file of the smart contract in this embodiment may contain descriptions of common security vulnerabilities of smart contracts, in the process of determining the formal verification rule statements suitable for formal verification methods that need to be generated According to the descriptions of these security vulnerabilities, it can be determined that these security vulnerabilities need to be generated and suitable for the formal verification method.

Optionally, in an example, extracting the information needed to generate formal verification rule statements from the information of the abstract syntax tree in the target file and the assembly code includes steps f and g:

Step f: Extract the information for generating formal verification rule statements from the assembly code in the target file;

Step g: If the extracted information is not enough to generate formal verification rule statements, extract the required information from the information of the abstract syntax tree in the target file.

Optionally, in another example, extracting information needed to generate formal verification rule statements from the information of the abstract syntax tree in the target file and the assembly code includes steps h and i:

Step h: Extract the contract object (contract) information needed to generate the formal verification rule statement from the information of the abstract syntax tree in the target file;

Step i: Extracting from the assembly code in the target file, except for contract information, generate information required for formal verification rule statements.

For example: in this embodiment, the declaration node for variable A will generate the corresponding data structure according to the attribute information of the variable: BitVec (variable A, 256), for logical judgments such as IF (A==B), formalization can be generated The validation rule statement is simplify(And(p,q,True)).

Optionally, there are multiple purposes of formal verification in this embodiment, such as detecting ERC20 tokens and detecting fake recharge vulnerabilities, etc. The purpose of formal verification is different, and the rules and sentences called are also different.

In this embodiment, the advantage of formal verification based on xSol is that there is no need to extract the source code (such as using keywords or regulars), and the location of functions and calling methods can be directly used based on the content of the copied abstract syntax tree . For the variables involved, when the source code of the smart contract is compiled into assembly code in related technologies, the code will be optimized, and some method names and variable names will be deleted and converted. This processing will bring about variable tracking and analysis. Inconvenience, this application can directly use the extractor call trace based on the content of the copied abstract syntax tree to determine whether the variable can be used, and xSol can also directly extract the source code of the node that needs to be used for specific analysis (for example, use the current node as For loop, get the source code of the code block involved directly through the source attribute).

The embodiment of the application discloses a formal verification method of a smart contract, which can obtain the source code of the smart contract to be verified, compile the source code of the smart contract into an abstract syntax tree, and disassemble the source code of the smart contract, Obtain the target file containing the assembly code of the smart contract, and convert the information in the abstract syntax tree to the target file; obtain the formal verification method corresponding to the smart contract, based on the assembly code in the target file and the abstract syntax tree in the target file Information, generate formal verification rule statements suitable for formal verification methods. In the above scheme, in the process of generating the abstract syntax tree, the variable names, method names, and logical relationships in the smart contract, such as the information of the inherited parent class, etc. , Will be reflected in the abstract syntax tree, so the information of the abstract syntax tree in the target file can make up for the defects of the assembly code of the smart contract to a certain extent. In the generated formal verification rule statement, some information in the assembly code In the case of missing, the missing information can be obtained from the information of the language abstract syntax tree, the rule statements can be extracted more comprehensively, and the defects caused by optimization after the compilation of different versions of the source code can be reduced, which is conducive to improving the formalization of smart contracts The accuracy of verification and the security of smart contracts are guaranteed.

The second embodiment:

The second embodiment of the present application provides an electronic device. Referring to FIG. 4, the electronic device includes:

The compilation module 401 is used to obtain the source code of the smart contract to be verified, compile the source code of the smart contract into an abstract syntax tree, and disassemble the source code of the smart contract to obtain a target file containing the assembly code of the smart contract;

The conversion module 402 is used to convert the information in the abstract syntax tree to the target file;

The generation module 403 is used to obtain the formal verification method corresponding to the smart contract, and generate formal verification rule statements suitable for the formal verification method based on the assembly code in the target file and the information of the abstract syntax tree in the target file;

The verification module 404 is used to perform formal verification of the smart contract according to the generated rule statement.

Optionally, the compiling module 401 is used to extract keywords or identifiers from the source code of the smart contract using a preset syntax analyzer, and use each keyword or identifier as one of the abstract syntax trees of the smart contract Node: According to the location and order of the extracted keywords or identifiers, the hierarchical relationship of the nodes corresponding to the keywords or identifiers is divided, and the abstract syntax tree of the smart contract is formed by all the nodes and the relationships between the nodes.

Optionally, the conversion module 402 is specifically used to analyze the node type of each node in the abstract syntax tree; according to the node type, the information of the nodes in the abstract syntax tree is copied to the target file, wherein, in the target file obtained after copying , The information of the node of the same type in the abstract syntax tree is located under the corresponding name of the same node type.

Optionally, the generation module 403 is used to obtain the security requirements of the smart contract, and based on the security requirements and the formal verification method, determine the formal verification rule statements suitable for the formal verification method to be generated; from the abstract grammar in the target file From the tree information and assembly code, the information needed to generate formal verification rule statements is extracted; based on all the extracted information and the formal verification method, a formal verification rule statement suitable for the formal verification method is generated.

In an example, the generation module 403 is specifically used to extract information for generating formal verification rule statements from the assembly code in the target file; if the extracted information is not enough to generate formal verification rule statements, abstract from the target file The method of extracting the required information from the information of the syntax tree, and extracting the information needed to generate the formal verification rule statement.

In another example, the generating module 403 is specifically used to extract the contract object information needed to generate formal verification rule statements from the information of the abstract syntax tree in the target file; extract the contract object information from the assembly code in the target file In addition, the method of generating the information required for the formal verification rule statement is to extract the information required for generating the formal verification rule statement.

The embodiment of the application discloses an electronic device, which can extract rule statements more comprehensively based on the information of the abstract syntax tree in the target file, reduce the defects caused by optimization after the compilation of different versions of the source code, and is beneficial to improve the smart contract The accuracy of formal verification and the security of smart contracts are guaranteed.

The third embodiment:

Please refer to FIG. 5. FIG. 5 is an electronic device provided by a third embodiment of this application. The electronic device can be used to implement the formal verification method of the smart contract in the embodiment shown in FIG. 2. As shown in Figure 5, the electronic device mainly includes:

The memory 501, the processor 502, the bus 503, and a computer program stored on the memory 501 and running on the processor 502, the memory 501 and the processor 502 are connected through the bus 503. When the processor 502 executes the computer program, it implements the formal verification method of the smart contract in the embodiment shown in FIG. 2. The number of processors may be one or more, which is not limited in this embodiment.

The memory 501 may be a high-speed random access memory (RAM, Random Access Memory) memory, or a non-volatile memory (non-volatile memory), such as a magnetic disk memory. The memory 501 is used to store executable program elements, and the processor 502 is coupled with the memory 501.

Further, an embodiment of the present application also provides a storage medium, which may be the electronic device provided in the foregoing embodiments, and the storage medium may be the memory in the embodiment shown in FIG. 5. Wherein, the computer-readable storage medium may be non-volatile or volatile.

A computer program is stored on the storage medium, and when the program is executed by the processor, the formal verification method of the smart contract in the embodiment shown in FIG. 2 is realized. Further, the computer storage medium may also be a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a RAM, a magnetic disk, or an optical disk and other various media that can store program elements.

Using the electronic device of this embodiment, based on the coding process of the assembly code of the software to be detected, the coding characteristics of the detection software can be obtained, making it easier for the deep neural network to find the commonalities between malware, and improving the application’s ability to identify various types of malicious software. The universality of software, the use of deep neural networks to determine whether the software to be detected is malicious software can further ensure effective identification of malicious software.

In the several embodiments provided in this application, it should be understood that the disclosed device and method may be implemented in other ways. For example, the device embodiments described above are merely illustrative, for example, the division of modules is only a logical function division, and there may be other divisions in actual implementation, for example, multiple modules or components can be combined or integrated. To another system, or some features can be ignored, or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or modules, and may be in electrical, mechanical or other forms.

The modules described as separate components may or may not be physically separate, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist alone physically, or two or more modules may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or software functional modules.

If the integrated module is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of this application essentially or the part that contributes to the existing technology or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a readable storage. The medium includes a number of instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods in the various embodiments of the present application. The aforementioned readable storage medium includes: U disk, mobile hard disk, ROM, RAM, magnetic disk or optical disk and other media that can store program elements.

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application. Should be covered within the scope of protection of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A formal verification method for smart contracts, including:

Obtaining the source code of the smart contract to be verified, compiling the source code of the smart contract into an abstract syntax tree, and disassembling the source code of the smart contract to obtain a target file containing the assembly code of the smart contract;

Converting the information in the abstract syntax tree to the target file;

Acquiring a formal verification method corresponding to the smart contract, and generating formal verification rule statements suitable for the formal verification method based on the assembly code in the target file and the information of the abstract syntax tree in the target file;

Perform formal verification of the smart contract according to the generated rule statement.
The method for formal verification of a smart contract according to claim 1, wherein said compiling the source code of the smart contract into an abstract syntax tree comprises:

Use a preset syntax analyzer to extract keywords or identifiers from the source code of the smart contract, and use each keyword or identifier as a node in the abstract syntax tree of the smart contract;

According to the extracted position and order of the keywords or identifiers, the hierarchical relationship of the nodes corresponding to the keywords or identifiers is divided, and the abstract syntax tree of the smart contract is formed by all the nodes and the relationships between the nodes .
The method for formal verification of a smart contract according to claim 1, wherein said converting the information in the abstract syntax tree to the target file comprises:

Analyzing the node type of each node in the abstract syntax tree;

The information of the nodes in the abstract syntax tree is copied to the target file according to the node type, wherein, in the target file obtained after copying, the information of the nodes of the same type in the abstract syntax tree is located in the target file Corresponding to the same node type name.
The method for formal verification of a smart contract according to any one of claims 1-3, wherein the generating is suitable for all based on the assembly code in the target file and the information of the abstract syntax tree in the target file The formal verification rules of the formal verification method include:

Acquiring the security requirements of the smart contract, and determining the formal verification rule statements suitable for the formal verification method that need to be generated based on the security requirements and the formal verification method;

Extracting the information needed to generate the formal verification rule statement from the information of the abstract syntax tree in the target file and the assembly code;

Based on all the extracted information and the formal verification method, a formal verification rule sentence suitable for the formal verification method is generated.
The method for formal verification of a smart contract according to claim 4, wherein said extracting from the information of the abstract syntax tree and the assembly code in the target file the information needed to generate the formal verification rule statement comprises:

Extracting the information for generating the formal verification rule statement from the assembly code in the target file;

If the extracted information is not enough to generate the formal verification rule statement, then the required information is extracted from the information of the abstract syntax tree in the target file.
The method for formal verification of a smart contract according to claim 4, wherein said extracting from the information of the abstract syntax tree and the assembly code in the target file the information needed to generate the formal verification rule statement comprises:

Extracting the contract object information needed to generate the formal verification rule statement from the information of the abstract syntax tree in the target file;

In addition to the contract object information, the information needed to generate the formal verification rule statement is extracted from the assembly code in the target file.
An electronic device, including:

The compilation module is used to obtain the source code of the smart contract to be verified, compile the source code of the smart contract into an abstract syntax tree, and disassemble the source code of the smart contract to obtain the assembly containing the smart contract The object file of the code;

A conversion module for converting the information in the abstract syntax tree to the target file;

The generation module is used to obtain the formal verification method corresponding to the smart contract, and generate a form suitable for the formal verification method based on the assembly code in the target file and the information of the abstract syntax tree in the target file Validation rule statement;

The verification module is used to perform formal verification of the smart contract according to the generated rule statement.
The electronic device according to claim 7, wherein the compiling module is configured to use a preset syntax analyzer to extract keywords or identifiers from the source code of the smart contract, and extract each keyword or identifier Symbol as a node in the abstract syntax tree of the smart contract; according to the extracted position and order of the keywords or identifiers, the hierarchical relationship of the nodes corresponding to the keywords or identifiers is divided, and all nodes And the relationship between nodes forms an abstract syntax tree of the smart contract.
An electronic device, wherein the electronic device includes a memory and a processor, the processor and the memory are connected to each other, wherein the memory is used to store a computer program, and the computer program includes program instructions. The processor is configured to execute the program instructions of the memory, wherein:

Obtaining the source code of the smart contract to be verified, compiling the source code of the smart contract into an abstract syntax tree, and disassembling the source code of the smart contract to obtain a target file containing the assembly code of the smart contract;

Converting the information in the abstract syntax tree to the target file;

Acquiring a formal verification method corresponding to the smart contract, and generating formal verification rule statements suitable for the formal verification method based on the assembly code in the target file and the information of the abstract syntax tree in the target file;

Perform formal verification of the smart contract according to the generated rule statement.
The electronic device according to claim 9, wherein the processor is configured to:

Use a preset syntax analyzer to extract keywords or identifiers from the source code of the smart contract, and use each keyword or identifier as a node in the abstract syntax tree of the smart contract;

According to the extracted position and order of the keywords or identifiers, the hierarchical relationship of the nodes corresponding to the keywords or identifiers is divided, and the abstract syntax tree of the smart contract is formed by all the nodes and the relationships between the nodes .
The electronic device according to claim 9, wherein the processor is configured to:

Analyzing the node type of each node in the abstract syntax tree;

The information of the nodes in the abstract syntax tree is copied to the target file according to the node type, wherein, in the target file obtained after copying, the information of the nodes of the same type in the abstract syntax tree is located in the target file Corresponding to the same node type name.
The electronic device according to any one of claims 9-11, wherein the processor is configured to:

Acquiring the security requirements of the smart contract, and determining the formal verification rule statements suitable for the formal verification method that need to be generated based on the security requirements and the formal verification method;

Extracting the information needed to generate the formal verification rule statement from the information of the abstract syntax tree in the target file and the assembly code;

Based on all the extracted information and the formal verification method, a formal verification rule sentence suitable for the formal verification method is generated.
The electronic device according to claim 12, wherein the processor is configured to:

Extracting the information for generating the formal verification rule statement from the assembly code in the target file;

If the extracted information is not enough to generate the formal verification rule statement, then the required information is extracted from the information of the abstract syntax tree in the target file.
The electronic device according to claim 12, wherein the processor is configured to:

Extracting the contract object information needed to generate the formal verification rule statement from the information of the abstract syntax tree in the target file;

In addition to the contract object information, the information needed to generate the formal verification rule statement is extracted from the assembly code in the target file.
A computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, the computer program includes program instructions, and when the program instructions are executed by a processor, they are used to implement the following steps:

Obtaining the source code of the smart contract to be verified, compiling the source code of the smart contract into an abstract syntax tree, and disassembling the source code of the smart contract to obtain a target file containing the assembly code of the smart contract;

Converting the information in the abstract syntax tree to the target file;

Acquiring a formal verification method corresponding to the smart contract, and generating formal verification rule statements suitable for the formal verification method based on the assembly code in the target file and the information of the abstract syntax tree in the target file;

Perform formal verification of the smart contract according to the generated rule statement.
The computer-readable storage medium according to claim 15, wherein when the program instructions are executed by the processor, they are further used to implement the following steps:

Use a preset syntax analyzer to extract keywords or identifiers from the source code of the smart contract, and use each keyword or identifier as a node in the abstract syntax tree of the smart contract;

According to the extracted position and order of the keywords or identifiers, the hierarchical relationship of the nodes corresponding to the keywords or identifiers is divided, and the abstract syntax tree of the smart contract is formed by all the nodes and the relationships between the nodes .
The computer-readable storage medium according to claim 15, wherein when the program instructions are executed by the processor, they are further used to implement the following steps:

Analyzing the node type of each node in the abstract syntax tree;

The information of the nodes in the abstract syntax tree is copied to the target file according to the node type, wherein, in the target file obtained after copying, the information of the nodes of the same type in the abstract syntax tree is located in the target file Corresponding to the same node type name.
The computer-readable storage medium according to any one of claims 15-17, wherein when the program instructions are executed by the processor, they are further used to implement the following steps:

Acquiring the security requirements of the smart contract, and determining the formal verification rule statements suitable for the formal verification method that need to be generated based on the security requirements and the formal verification method;

Extracting the information needed to generate the formal verification rule statement from the information of the abstract syntax tree in the target file and the assembly code;

Based on all the extracted information and the formal verification method, a formal verification rule sentence suitable for the formal verification method is generated.
The computer-readable storage medium according to claim 18, wherein when the program instructions are executed by the processor, they are further used to implement the following steps:

Extracting the information for generating the formal verification rule statement from the assembly code in the target file;

If the extracted information is not enough to generate the formal verification rule statement, then the required information is extracted from the information of the abstract syntax tree in the target file.
The computer-readable storage medium according to claim 18, wherein when the program instructions are executed by the processor, they are further used to implement the following steps:

Extracting the contract object information needed to generate the formal verification rule statement from the information of the abstract syntax tree in the target file;

In addition to the contract object information, the information needed to generate the formal verification rule statement is extracted from the assembly code in the target file.