JP2002099439A - Link method of library applicable to computer system and record medium recorded its program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a link method of a library applicable to a computer system and a record medium recorded its program capable of calling a function by a link library only with an arbitrary executive program. SOLUTION: In an executive program 30 to authorize a link to a library 40, a recognition code is placed, so that a key generated from the code encrypts a function that is in a high confidential among the library 40. When loading actually the library 40 from the program 30, since a control covers an initializing routine 44 in the library 40, at that time, an identification code 33 is searched with scanning a side of the program 30. Only when the code 33 in the program 30 is found, a calling of the function is made possible with expanding of functions 45 and 46 in the encrypted library.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a library linking method applied to a computer system and a recording medium recording the program.

[0002]

2. Description of the Related Art In software development, programs having similar functions are collectively prepared as a library in order to save the trouble of repeatedly creating the same program. A program that uses the library can be compiled with the library at the time of compilation, so that the program code in the library can be used only with the function declaration.

[0003] The library has the drawback that the capacity of an executable program to be generated is increased, and that it is necessary to compile each program that uses the functions of the library. A dynamic link library is used to solve these problems.

[0004] Dynamic link libraries are dynamically called during the execution of program code. The system loads the library into memory in response to a program request. The program calls functions in the library and releases them when they are no longer needed. According to this method, the library can be used without compiling any program code, and the program is loaded as needed, so that the size of the execution program is not reduced.

[0005]

However, if it is desired to permit the use of the library only for a specific executable file, the advantage of the dynamic link library becomes a problem. Any program can use the program in the library as long as it can declare the function, so even if it is a highly confidential function or a function that does not work properly unless it is a specific program, it can be called from other programs Because it becomes.

A system in which a library selects an execution program has been set up in the data processing system disclosed in Japanese Patent Application Laid-Open No. 06-083593 (1994-03-25) in which a program is automatically linked by a linker. Japanese Patent Application Laid-Open No. 08-241207 (1996-09) in which a kernel selects a library to be dynamically linked from a server according to a security level
-17). However, the former is a system for searching for and solving unresolved references, and cannot be used for the purpose of not linking with other than the specific program of the present invention. The latter has a problem that the operating system needs to be changed and cannot be used for the existing system.

When accessing the contents of an encrypted CAD library corresponding to a CAD program,
Japanese Patent Application Laid-Open No. 2000-76313 (2000-03-2000) discloses a CAD library access management device for transmitting information of a decrypted CAD library only in response to an access request based on a formal license.
14). FIG. 7 shows the configuration of the CAD library access management device. The CAD library access management device 100 is incorporated in the file system 200.
Performs most of the process of granting links. That is, it is necessary to modify the operating system or prepare such an operating system.
Also, as can be seen from FIG. 7, it is necessary to separately prepare license information 60 indicating access permission / non-permission of the library, access right management target path definition information 50, and the like.

An object of the present invention is to solve the above problems,
An object of the present invention is to provide a link method of a library applied to a computer system and a recording medium storing the program so that the link library can call a function only by an arbitrary execution program.

[0009]

The library linking method applied to the computer system of the present invention is applied to a computer system having a link function for linking a program to be executed with a library prepared in advance. A method of linking a library, in which an initialization routine in the library is called by dynamically loading the library, which is processing on the execution program side, and the initialization routine sequentially scans a binary image on the execution program side to identify If you find the code and if the identification code is correct, complete the initialization process normally.If the identification code is not found or if the identification code is incorrect,
A step of not loading the library due to a failure in the initialization processing, a step of calling a function in the library by calling a function which is a processing of the execution program side, and scanning the binary image of the execution program side by the function to identify Finding the code and, if the identification code is correct, obtaining the decryption key from the identification code, decrypting the encrypted function and executing the function, and finding the identification code If the identification code is invalid, or if the identification code is invalid, it is determined that the library is called from an invalid execution program, and the process is stopped.

A library used in a program includes a dynamic link library. The dynamic link library is a mechanism that can be loaded on a memory as needed during the execution of a program and can call a function in the library. The dynamic link library is generally used for the purpose of saving the capacity of an executable program and sharing a frequently used function among multiple executable programs.

According to the present invention, the dynamic link library
Provides a mechanism that can be linked only from an arbitrary execution program. As a result, a highly confidential function that is not desired to be used by a third party can be used as a library that can be dynamically linked only from an arbitrary execution program.

A recognition code is placed in an execution program that permits linking to a library, and a highly confidential function in the library is encrypted with a key generated from the recognition code.

When the library is actually loaded from the execution program, the control of the initialization routine in the library is transferred. At that time, the execution program is scanned for the identification code. Only when it finds a recognition code in the execution program, expands the function in the encrypted library so that the function can be called.

As a result, a third party program without an identification code cannot use the functions of the library.

In addition, a step of calling an initialization routine in the library by dynamically loading the library, which is processing on the execution program side, and scanning the binary image on the execution program side in order by the initialization routine to search for an identification code. If the step and the identification code are correct, obtain the decryption key from the identification code, release the encrypted function and complete the initialization process normally, and if the identification code is not found If the identification code is invalid or the identification code is invalid, the initialization process fails and the library is not loaded. By scanning the binary image of the execution program side in order to search for the identification code, If the identification code is correct, obtain the decryption key from the identification code, decrypt the encrypted function and execute the function.If the identification code is not found or If it is the identification code, the process may include a step of determining that the library is called from an unauthorized execution program and stopping the processing.

That is, a key may be generated from the identification code at the time of the initialization routine to decrypt the function. Since the encryption is also released when the function is called, double encryption can be applied.

Further, a step of calling a function in the library by calling a function which is a process on the execution program side, a step of sequentially scanning a binary image of the execution program side by the function to search for an identification code, If the code is correct, obtain the decryption key from the identification code, decrypt the encrypted function and execute the function.If the identification code is not found or if the wrong identification code is used, If there is, a step of determining that the library is called from an unauthorized execution program and stopping the process may be performed.

That is, a static link library may be used instead of a dynamic link library. If you have to provide a statically linked library to a third party, and you have content to protect in that library and do not want to link it beyond a specific executable, you can use the method of the present invention . In the case of a statically linked library, there is no initialization routine, so only the method used when the function was called is used.

Further, the identification code may be stored in a data storage area, a code storage area, or a resource storage area of the execution program.

That is, the recognition code prepared in the execution file need not be a data storage area. By preparing a plurality of identification codes and distributing the storage locations, a system that is difficult to decipher can be obtained.

A recording medium storing a program set to be executed by the computer system of the present invention is read by a computer system having a link function for linking a program to be executed with a library prepared in advance. A recording medium capable of calling an initialization routine in the library by dynamically loading the library as a process on the execution program side;
An initialization routine for sequentially scanning the binary image on the execution program side to search for an identification code;
If the identification code is correct, the initialization process is completed normally.If the identification code is not found or the identification code is incorrect, the initialization Not loading, a step of calling a function in the library by calling a function which is a process of the execution program side, a step of sequentially scanning a binary image of the execution program side by the function to search for an identification code, If is the correct code, obtain the decryption key from the identification code, decrypt the encrypted function and execute the function, and if the identification code is not found or the incorrect identification code If so, it is determined that the library is being called from an invalid execution program, and the process is terminated. The door is set so that the computer system to perform.

In addition, a step of calling an initialization routine in the library by dynamically loading the library, which is processing on the execution program side, and scanning the binary image on the execution program side in order by the initialization routine to search for an identification code. If the step and the identification code are correct, obtain the decryption key from the identification code, release the encrypted function and complete the initialization process normally, and if the identification code is not found Or if the identification code is invalid, the initialization process fails, the step of not loading the library, the step of calling a function in the library by calling a function that is processing on the execution program side, The function scans the binary image on the execution program side in order and searches for the identification code. If, when the identification code is a valid code, with the key decryption from the identification code, performing a function to release the encrypted function,
If the identification code is not found or if the identification code is invalid, the computer system executes a step of determining that the library is called from an invalid execution program and stopping the processing. May be set to.

Further, a step of calling a function in the library by calling a function which is a process on the execution program side, a step of sequentially scanning a binary image of the execution program side by the function to search for an identification code, If the code is correct, obtain the decryption key from the identification code, decrypt the encrypted function and execute the function.If the identification code is not found or if the wrong identification code is used, If there is, the computer system may be set to execute the step of determining that the library is called from an unauthorized execution program and stopping the processing.

[0024]

FIG. 1 is a diagram showing a control flow of a general dynamic link library. Program 10
And a library 20. The execution program 10 is a program that calls a function in the library 20. The program 10 includes a process of dynamically loading a library 11 that causes the system to dynamically load a library, and a process of calling a function 12 to use a function 22 in the library.

The library 20 is a dynamic link library. Function 22, 2 called from the execution program
There are three.

By the dynamic loading 11 of the library, the control is transferred to the library, and the processing of the initialization routine 21 is performed. When this is complete, control returns to program 10 again. When the function 22 is called by the function call 12, the control is performed on the library side and the processing of the function 22 is performed. When this is completed, control returns to the program side.

FIG. 2 shows an example of an execution program and a library embodying the present invention. These are composed of a program 30 and a library 40.

The program 30 includes a data storage area 31 and a code storage area 34. The data storage area includes a global variable 32 and an identification code 33. The code storage area includes a library call process 35 and other processes 3
6 is included.

The library 40 includes a data storage area 41 and a code storage area 43, and the data storage area includes a global variable 42. The code storage area includes a library initialization process 44 and an encrypted function 45. A key for decrypting this encryption can be generated from the identification code 33.

In the present invention, the system configured in FIG. 2 operates as follows.

The initialization routine 21 in the library 20 is called by the dynamic loading 11 of the library shown in FIG.
As shown in FIG. 3, the initialization routine 21 sequentially scans the binary image 30 on the execution program side to search for the identification code 33. If this is the correct code, the initialization process is completed normally. If the identification code is not found or is an invalid identification code, the initialization process fails and the library is not loaded.

When called by function call 12 of FIG. 1, function 22 examines program binary image 30 for an identification code 33. The decryption key is obtained from the identification code, and the encrypted function 45 is decrypted and returned to the function 22 to execute the function.

The function 23 performs the same processing.

If the identification code is not found, it is determined that the library is called from an unauthorized execution program, and the processing is stopped.

In the present invention, the control flow shown in FIG. 1 does not change. There are processes performed in addition to the processes performed on the library side. The overall operation of the present invention will be described in detail with reference to the flowcharts of FIGS.

FIG. 4 is a flowchart showing the operation performed by the library initialization processing. In the case of a permitted execution program In the library initialization routine 21 called by the dynamic loading of the library 11 in FIG. 1, first, the binary code of the program that called itself is checked from the beginning (step A1).

A3 if the identification code found in the program is found by this check, A if not
Branching to step 4 (step A2).

It is checked whether the obtained identification code is correct (step A3).

Since the program which called the library is not a permitted program, the initialization is failed (step A4).

Since the program that called the library was a permitted program, the initialization was successful (step A5). In the case of an execution program having no identification code The binary code of the program that called itself is checked from the beginning (step A1).

Since the identification code is not found in the program by this check, the flow branches to A4 (step A).
2).

Since the program that called the library is not a permitted program, the initialization is failed (step A4).

FIG. 5 is a flowchart showing the pre-processing operation when a function of the library is called during execution of the program. In the case of a permitted execution program The function in the library called by the function call 12 in FIG. 1 first checks the binary code of the program that called itself from the beginning (step B1).

Since the identification code located in the program is found by this inspection, the flow branches to B3 (step B).
2).

When it is checked that the identification code is correct, B4
Branch to (step B3).

A decryption key is generated from the identification code (step B4).

The encryption applied to a part of the function is released with the key (step B5).

Since the program that called the function was a permitted execution program, the function is executed (step B7). In the case of an execution program having no identification code First, the binary code of the program that called itself is checked from the beginning (step B1).

Since the identification code is not found by this inspection, the flow branches to B6 (step B2).

Since the program that called the function was not a permitted execution program, the function cannot be executed (step B6).

As described above, by placing the identification code in the program that calls the library and encrypting the function in the library with the key generated from the code,
It is possible to prevent an executable program without an identification code from calling and using the library.

In the procedure for generating a key from an identification code, it is desirable to use a value obtained by performing a logical operation or the like a plurality of times from the identification code.

(Other Embodiments of the Invention) A static link library may be used instead of a dynamic link library.

If the static link library must be provided to a third party, and the library has contents to be protected and it is not desired to link other than a specific executable file, use the method of the present invention. be able to. In the case of a statically linked library, there is no initialization routine, so only the method used when the function was called is used.
In this case, it does not make sense to notify the library providing destination of the identification code, so that known information such as the execution file name must be used as the identification code. -The recognition code prepared in the execution file does not have to be the data storage area.

As in the example shown in FIG. 6 where the identification codes are distributed and stored, the recognition codes may be embedded in a pattern of a program code or an image file stored in an execution file.

By preparing a plurality of identification codes and distributing the storage locations, a system that is difficult to decipher can be obtained. In this case, the type of the identification code is the type of the key. Assigning one type of key to each function results in a library that, even if one identification code is known, does not affect other encrypted functions. In addition, if all functions perform encryption using a plurality of keys, a single library having high security strength can be obtained. -Generate a key from the identification code during the initialization routine,
The function can be decrypted.

Since the encryption is also released when the function is called, double encryption can be applied. In this case, it is necessary to prepare a key having a common key and a different encryption algorithm.

[0058]

As described above, the effect of the present invention is as follows.
The object of the present invention is to make it possible to create a dynamically linked library that cannot call its functions from any program other than an arbitrary executable program.

The reason is that when the dynamic link library passes through the initialization routine, and when the function is called from the execution program, the identification code embedded in the execution program is scanned and the dynamic link library is scanned. To check whether the program allows linking.

The identification code is a key for decrypting the library.

In addition, a static link library may be used instead of the dynamic link library.

When a static link library must be provided to a third party, and the library has contents to be protected and it is not desired to link other than a specific executable file, the method of the present invention is used. be able to.

The recognition code prepared in the execution file need not be a data storage area. By preparing a plurality of identification codes and distributing the storage locations, a system that is difficult to decipher can be obtained.

In the initialization routine, a key may be generated from the identification code to decrypt the function. Since the encryption is also released when the function is called, double encryption can be applied.

[Brief description of the drawings]

FIG. 1 is a diagram of general control when a dynamic library is used.

FIG. 2 is a diagram of a binary image of a library and an executable file to which the present invention is applied.

FIG. 3 is a diagram of a binary check of a library initialization routine to which the present invention is applied.

FIG. 4 is a flowchart of a binary inspection process of an initialization routine.

FIG. 5 is a flowchart of a pre-process in which a function is executed.

FIG. 6 is a configuration diagram in a case where identification codes are stored in a distributed manner.

FIG. 7 is a diagram showing a configuration of a conventional CAD library access management device.

[Explanation of symbols]

 Reference Signs List 10 program 11 processing for loading library into system 12 processing for calling library function 20 library 21 initialization routine 22 to 23 called function 30 program 31, 41 data storage area 32, 42 global variable 33 identification code 34, 43 code storage Area 35 Processing for loading library into system 36 Other processing 37 Other processing storing identification code 38 Resource storage area 39 Image data storing identification code 40 Library 44 Library initialization processing 45, 46 Encrypted function Reference numeral 50: access right management target path definition information 60: license information 100: CAD library access management device 102: access destination path confirmation processing unit 104: access right confirmation processing unit 106: library decryption Encryption processing unit 110 File access processing unit 120 File access request source 130 Encrypted library 140 File not accessed for access 200 File system

Claims (8)

[Claims] 1. A library linking method applied to a computer system having a link function for linking a program to be executed with a library prepared in advance, the library linking method being a process on the execution program side. Calling an initialization routine in the library by dynamic loading; scanning the binary image of the execution program side in order by the initialization routine to search for an identification code; and when the identification code is a correct code. Is a step of successfully completing the initialization process, and if the identification code is not found, or if the identification code is incorrect, the initialization process is a failure,
A step of not loading the library; a step of calling a function in the library by calling a function which is a process on the execution program side; and a step of sequentially scanning a binary image on the execution program side by the function to search for an identification code. If the identification code is a correct code, obtain a decryption key from the identification code, decrypt the encrypted function and execute the function; and if the identification code is not found, Or, if the identification code is invalid, determining that the library is called from an invalid execution program, and stopping the processing, and linking the library. 2. A library linking method applied to a computer system having a link function for linking a program to be executed with a library prepared in advance, the method comprising: Calling an initialization routine in the library by dynamic loading; scanning the binary image of the execution program side in order by the initialization routine to search for an identification code; and when the identification code is a correct code. Obtaining a decryption key from the identification code, decrypting the encrypted function and completing the initialization process normally; and when the identification code is not found, or with an incorrect identification code. If there is, the initialization process will be failed,
A step of not loading the library; a step of calling a function in the library by calling a function that is a process of the execution program; and a step of sequentially scanning a binary image of the execution program by the function to search for an identification code. Obtaining the decryption key from the identification code if the identification code is a correct code, decrypting the encrypted function and executing the function, and if the identification code is not found Or, if the identification code is invalid, determining that the library is called from an invalid execution program, and stopping the processing, and linking the library. 3. A method of linking a library to be applied to a computer system having a link function for linking a program to be executed with a library prepared in advance, wherein the function is a call on the execution program side. Calling a function in the library by using the function, sequentially scanning a binary image on the execution program side to search for an identification code, and, if the identification code is a correct code, Obtaining a decryption key, decrypting the encrypted function, and executing the function; if the identification code is not found, or if the identification code is incorrect, the library is Determining that the library is called from the program and stopping the processing. Click method. 4. The library link method according to claim 1, wherein the identification code is stored in a data storage area, a code storage area, or a resource storage area of the execution program. 5. A recording medium readable by a computer system having a link function for performing a link process between a program to be executed and a library prepared in advance. Calling an initialization routine in the library by loading; scanning the binary image on the execution program side in order to search for an identification code by the initialization routine; and if the identification code is a correct code, A step of normally completing the initialization processing; and if the identification code is not found, or if the identification code is invalid, the initialization processing is considered to have failed,
A step of not loading the library; a step of calling a function in the library by calling a function which is a process on the execution program side; and a step of sequentially scanning a binary image on the execution program side by the function to search for an identification code. If the identification code is a correct code, obtain a decryption key from the identification code, decrypt the encrypted function and execute the function; and if the identification code is not found, Or, if the identification code is invalid, determining that the library is called from an invalid execution program, and stopping the process. The recording medium on which it was recorded. 6. A recording medium readable by a computer system having a link function for performing link processing between a program to be executed and a library prepared in advance, wherein dynamic processing of the library which is processing on the execution program side is performed. Calling an initialization routine in the library by loading; scanning the binary image on the execution program side in order to search for an identification code by the initialization routine; and if the identification code is a correct code, Obtaining a decryption key from the identification code, decrypting the encrypted function and completing the initialization process normally, and if the identification code is not found, or if the identification code is invalid. The initialization process fails,
A step of not loading the library; a step of calling a function in the library by calling a function which is a process on the execution program side; and a step of sequentially scanning a binary image on the execution program side by the function to search for an identification code. If the identification code is a correct code, obtain a decryption key from the identification code, decrypt the encrypted function and execute the function; and if the identification code is not found, Or, if the identification code is invalid, determining that the library is called from an invalid execution program, and stopping the process. The recording medium on which it was recorded. 7. A recording medium readable by a computer system having a link function for performing link processing between a program to be executed and a library prepared in advance. A step of calling a function in the library; a step of sequentially scanning a binary image on an execution program side by the function to search for an identification code; and, if the identification code is a correct code, a code from the identification code. Obtaining a key for unlocking, executing the function by unlocking the encrypted function, and, if the identification code is not found or if the identification code is incorrect, the library executes an incorrect execution program. Determining that the process is called from the computer system and stopping the process. A recording medium recording a program set to run. 8. The storage medium according to claim 4, wherein the identification code is stored in a data storage area, a code storage area, or a resource storage area of the execution program.
A recording medium recording a program set to be executed by the computer system according to the item.