KR100871679B1 - Method for providing the educational virtual os environment using the security kernel - Google Patents

Abstract

The present invention relates to a method for providing a virtual operating system environment for education using a secure kernel for providing a virtual operating system environment for education using a security kernel so that each system is viewed as a different system for each user. A virtual system that grants security attributes to the system, allows the user to access only his or her own processes and files, and processes and files of the system, and controls access to other users' processes and files. Educational virtual operating system environment using the secure kernel that makes the original environment by configuring the environment and distinguishing by user even if the user is given root authority and changing the path to the copied file by using redirection at the kernel level. offer It is about a method.

Virtual operating system, security kernel, file system, security role, security category

Description

METHOOD FOR PROVIDING THE EDUCATIONAL VIRTUAL OS ENVIRONMENT USING THE SECURITY KERNEL}

1 is a block diagram of an overall system for implementing a method for providing an educational virtual operating system environment using the security kernel of the present invention.

2 is a flowchart illustrating a method for providing an educational virtual operating system environment using the secure kernel of the present invention.

3 is a user security role.

4 is a structural diagram of a file system in a virtual operating system.

5 is an access structure diagram for a file system and a process.

6 is a file system redirection and access structure diagram.

7 is a file system security attribute table.

8 is an emulator processing flowchart.

delete

9 is a process security attribute table.
10 is a process control processing flowchart.

11 is a file system control processing flowchart.

* Description of the main parts of the drawings *

101: user security attribute setting unit 102: file system security attribute setting unit

103: emulator processing unit 104: system call control unit

105: process control unit 106: file system control unit

107: User Security Attributes DB 108: Process Security Attributes Table

109: Filesystem Security Attribute Table

The present invention relates to a method for providing a virtual operating system environment for education using a secure kernel that allows multiple users to simultaneously perform multiple operations on a file on a system.

It is difficult for multiple users to work on a file at the same time on one system, and it is difficult to give administrator rights to multiple users. When training with administrator authority, one system is needed per person, and the system environment is changed after training and needs to be restored.

To overcome this disadvantage, virtualization technology is used. Virtualization technologies such as VMWare run multiple operating systems simultaneously on one system.

However, in order to educate as an administrator, one operating system is required per person, and the virtualization technology is limited by the number of users for training because the number of operating systems that can be installed is limited according to system size and performance.

An object of the present invention for solving the above problems is to provide a virtual operating system environment so that it seems to use a unique system for each user by using a secure kernel in one operating system.

In addition, another object of the present invention is to provide a virtual operating system environment to provide a one-to-one corresponding system to each user when a plurality of users in one operating system irrespective of the number of operating systems configured by the virtualization technology.

Another object of the present invention is to provide a virtual operating system environment so that the original system environment is preserved and easily restored after the training even if the system environment is educated with root authority for various users.

1 is a diagram illustrating an overall system showing a method for providing a virtual operating system environment using a secure kernel in the present invention.

In order to implement a method for providing a virtual operating system environment using a secure kernel according to the present invention, the security kernel includes a user security attribute setting unit 101, a file system security attribute setting unit 102, an emulator processing unit 103, and a system call control unit. It comprises the 104, the process control part 105, and the file system control part 106. As shown in FIG.

The user security attribute setting unit 101 defines a security attribute for a system user and stores the security attribute in the user security attribute DB 107.

The user security attribute includes a user information, a security role, and a category for each user.

The system security manager sets, changes, and deletes file system security attributes in the file system security attribute setting unit 102 and stores the set file system security attribute table 109 in the kernel.

The emulation processor 103 does not provide actual system information, but provides only system information necessary for a virtual environment or processes related instructions to be processed by an emulator in order to prevent malfunction of the system.

The system call control unit 104 performs a role of filtering only system calls related to access control.

The process control unit 105 sets a security attribute for the newly created process and provides a control function for the process so as not to interfere with another user's work.

When the newly generated process occurs, the process control unit 105 searches the user security attribute DB 107 based on the process user information, and configures the process security attribute table 108 by using the same.

The process security attribute table 108 includes three fields: a security role field 801, a control field 802, and a category field 804 for each user.

2 illustrates the overall sequence through the entire flow chart of the method for providing a virtual operating system environment using the secure kernel of the present invention, and the detailed sequence and description thereof will be described with reference to FIGS. 3 to 9.

As shown in FIG. 2, the system security manager sets, changes, and deletes user security attributes in the user security attribute setting unit 101 and stores the set security attributes in the user security attributes DB 107 of the kernel. )

The user security attribute set in step (a) is configured to include user information, security role, and category for each user. Accordingly, roles and categories separated for each user are managed to manage the actual OS environment and the virtual OS environment. define.

3 defines security roles and categories among user security attributes.

The security role is divided into a security manager 501, a virtual user 502, and a system user 503.

First, the security manager 501 is a user who is separately authorized as a user performing a top-level root role, and the security manager 501 is a user for managing an actual operating system environment.

The virtual user 502 is defined as an education user who uses a service as a user who uses a virtual operating system. The virtual user 502 is given a separate category for each user.

The system user 503 is defined as a system user of an account required for system operation and service, and can be viewed as a system service rather than a user, and a person who is a general user who uses the service does not belong to this.

After the user security attributes are stored by the security administrator, as shown in FIG. 2, the system security administrator sets, changes, and deletes the file system security attributes in the file system security attribute setting unit 102 and sets the file system security. The attribute table 109 is stored in the kernel. (B)

4 illustrates a file system structure in a virtual operating system environment of the present invention.

The file system of the virtual operating system is largely divided into a user area 201 and a system area 202.

The user area 201 is an area where users can read, write, and execute freely, and means a home directory for each user.

The remaining area excluding the user area is left as the system area 202, and basically only read and execute are possible.

The prohibition of writing in the system area 202 is intended to prevent the system from being deformed and has a separate writable area 203 for the part requiring the file change.

The file in the writable area 203 is maintained as a redirection list, and in the case of a file in which a redirection is declared, the original file is kept as it is and the file is redirected to the copied file so that writing is performed.

The shutdown, reboot, and halt commands in a system can halt the system and services, and have a separate execution control area 204 to prevent this.

The execution control area 204 is managed by the command control list.

5 shows a process and file system access structure in the virtual operating system environment of the present invention.

In the present invention, all processes and file systems are classified and controlled by security attributes used in the security kernel.

All users are allowed access only to their own processes and files, and to processes and files on the system, and to other users' processes and files.

Users can access and control all of their processes and files, but they can access system processes and files, but their behavior is controlled. The user can see the system processes but cannot stop them, and access to the file system follows the access rules to the system area shown in FIG.

6 shows a redirection and access structure for the file system of the present invention.

The files in the writable area 203 have a file in which a redirection flag is declared and the original file is maintained and copied for each user.

When a user wants to access a file for which a redirect has been declared, change the access path from the security kernel to the original file to access the copied file for each user.

7 shows a file system security attribute table structure in a virtual operating system environment.

The file system security attribute table consists of three fields: a security role field 601, a redirection and command control field 602, and a category field 603 for each user.

The security role field 601 stores security role (security manager, virtual user, system user) information on the file system.

The category for each virtual user is stored in the category category for each user.

The redirection and command control field 602 declares a redirection flag to indicate that it is a file in the writable area 203 and an execution control flag to indicate that it is a file in the execution control area 204.

As shown in FIG. 2, after the user security attributes and the file system security attributes table are created and stored, when a user executes a command, the emulator processing unit 103 converts and executes the command to provide a virtual environment. )

The emulation processing unit 103 does not provide actual system information but provides only system information necessary for a virtual environment or related instructions are processed by an emulator to prevent a system malfunction.

8 shows an instruction processing flowchart of the emulator.

When the user executes an instruction, the emulation processor 103 checks whether the instruction is an emulated instruction, in step 701.

If it is an emulated instruction, it performs an emulator instruction (702), and if it is not an emulated instruction, it performs a system instruction (703).

As shown in FIG. 2, when the (d) command is executed, a system call is generated, and the system call control unit 103 filters only system calls for file systems and processes.

The system call control unit 104 of step (d) performs a role of filtering only system calls related to access control.

In general, when an application is executed by a system or a user, a system call of an operating system occurs, and the operating system performs a function requested by the system call.

In the present invention, the system call control unit 104 replaces the system call of the function related to the present invention among the system calls of the operating system and calls the system call of the operating system after performing the function of the present invention.

In the present invention, the system call control unit 104 replaces the system call related to process control and file system access control among the system call of the operating system and calls the original system call after performing the replaced system call.

In addition, a control system call is added for security policy and security function environment setting used in the present invention.

As shown in FIG. 2, when a new process is generated by the step (c), the process control unit 105 configures the process security attribute table 108 by using the user security attribute DB 107 information, and the other process. (E) Control not to interfere with user processes.

10 shows a configuration of the process security attribute table and a process control flowchart accordingly.

The system call controller checks whether a new process is generated when the system call passes (901).

In this case, the process checks whether the user is a user login (902). If the process is not a new process, that is, a process to which a process security attribute is granted, the process attribute information is collected from the process security attribute table for the process policy violation check. (905).

In addition, in the case of a user login, a process security attribute is set (904). In the case of a process generation by an action other than the user login, the security attribute of the upper process is inherited (903). Inheriting the security attributes of the parent process means that when a user logs in, the security attributes are granted and inherited without changing the security attributes until the user logs out.

In the case of a user login, the process security attribute table configured by referring to the user security attribute DB to set the process security attribute is shown in FIG. 9.

The process security attribute table 108 includes three fields: a security role field 801, a control field 802, and a category field 804 for each user.

The security role field 801 represents a user role of the process (security manager, virtual user, system user).

The control field 802 stores control information used for process control.

The category field 803 for each user stores category information that can be classified for each user even in a root state for the virtual user.

After the process security attribute table is set, user information, security attribute information, and behavior information about the process are collected (905).

Based on the collected process information, it is verified whether the process access policy is violated (906).

The process access policy prevents users from stopping system processes even under root privileges and prevents other users from accessing processes. If the process access policy is violated, the countermeasures such as process suspension are performed. If the process access policy is not violated, the file system control unit is executed.

As shown in Fig. 2, the file system control unit 106 controls the system file and controls not to access another user's file. (F)

11 shows a file system control flowchart.

When the system call is over, the system call controller checks whether it is the redirection file (1001).

If the redirection file is a file in the writable area and the redirection is declared, the path to the copied file is changed (1002).

Next, it is checked whether the file is in the command control list (1003). If the file is on the command control list, stop the process.

In order to compare the file system access policy, attribute information about the process and the file system is collected (1004). Process and file system attribute information consists of user information and security attribute information.

When attribute information about the process and the file system are collected, the process checks whether the file system access policy is violated (1005).

Only read and execute files in the system area are allowed, and writes are allowed only in the redirect file. Also, if the file is in the user area, read, write, and execute is allowed only if the owner is the file. If the file is in another user area, access is denied. If the file system access policy is violated, countermeasures such as process stop are performed. If the file system is not violated, the original system call is executed.

As described in detail above, the method for providing a virtual operating system environment using the secure kernel of the present invention provides a virtual operating system environment so that a user can use a unique system for each user by using the secure kernel in one operating system, and an operating system configured by virtualization technology. By providing a virtual operating system environment so that if there are multiple users in one operating system, regardless of the number of users, the system will be preserved even if the system environment is trained with root privileges for multiple users. It can be easily restored after training.

In the above description, the technical idea of the method for providing a virtual operating system environment using the secure kernel of the present invention has been described with the accompanying drawings. However, the present invention has been described by way of example and is not intended to limit the present invention. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (12)

(a) setting, changing, and deleting the user security attributes by the user security attribute setting unit 101 and storing the set security attributes in the user security attributes DB 107 of the kernel; (b) setting, changing and deleting the file system security attributes by the file system security attribute setting unit 102 and storing the set file system security attribute table 109 in the kernel; (c) emulating the command executed by the user by the emulator processing unit 103 and converting the command into a command for providing a virtual environment; (d) when the system call is generated by executing the command of step (c), filtering only the system call for the file system and the process by the system call controller 103; (e) controlling, by the process control unit 105, to configure the process security attribute table 108 using the user security attribute DB 107 and not to interfere with another user's process; (f) the file system control unit 106, the system file is protected and controlled to prevent access to the files of other users, the virtual operating system environment providing method using a secure kernel, characterized in that the configuration. The method of claim 1, The user security attribute set in step (a) is configured to include user information, security role, and category for each user. Accordingly, roles and categories separated for each user are defined for actual OS environment management and virtual OS environment management. Method for providing a virtual operating system environment using a secure kernel, characterized in that. The method of claim 1, The file system security attribute table set in step (b) includes a security role field 601, a redirection and command control field 602, and a category field 603 for each user. How to provide operating system environment. The method according to claim 2 or 3, The security role constituting the user security attribute and file system security attribute table, and the category for each user according to each security role, A security manager 501 which is a separately authorized security manager as a user performing a top-level root role; A system user 503 which is a system user for managing an actual operating system environment; A user using a virtual operating system, which is defined as an educational user who uses a service, and is classified as a virtual user 502 divided into categories by a separate category even when a user is given a category divided by user and is authorized to move to root. How to provide a virtual operating system environment using a secure kernel. The method of claim 3, wherein The file system structure of step (b) is A user area 201 in which only the virtual user can read, write, and execute the home directory of the virtual user; It is divided into a system area 202 except for the user area, and which can be read and executed by a virtual user. The system region 202 is a writeable region 203 that can be written separately so that a virtual user can change it among the system regions that are prohibited from writing, and executes a specific command among system regions that are allowed to execute. A method for providing a virtual operating system environment using a secure kernel, comprising: an execution control area 204 managed by a command control list to prevent the system from being interrupted by the system. The method of claim 5, The file in the writable area 203 is maintained as a redirection list, and in the case of a file in which a redirection is declared, the virtual operating system environment using the secure kernel is characterized in that the original file is kept as it is and the write is performed by redirecting to the copied file. Way. The method according to claim 3 or 5, The redirection and command control field 602 declares a redirection flag to indicate that it is a file in the writable area 203 and a execution control flag to indicate that it is a file in the execution control area 204. How to provide virtual operating system environment using kernel. The method of claim 1, In the step (c), the instruction processing order of the emulator When the user executes the command, checking whether the command is emulated by the emulation processor 103 at step 701; Performing (702) an emulator instruction in the case of the emulated instruction; The method of providing a virtual operating system environment using the secure kernel, characterized in that the step of performing a system command (703) if not the emulated command. The method of claim 1, In the step (d), checking whether a new process is generated when a system call is passed to the system call controller (901); Checking whether it is a user login in the case of a new process (902); Setting 904 a process security attribute table using a user security attribute DB in case of a user login; Inheriting the security attributes of the parent process when the process is created by an action other than a user login—when a user executes a command or the like or a new process is created by the system—903; Collecting (905) process information after the process security attribute table is set; And a step 906 of verifying whether the process access policy is violated based on the collected process information. If the process access policy is violated, a corresponding action is performed, and if not, a file system control unit is performed. How to provide a virtual operating system environment using a secure kernel. 10. The process security attribute table 108 according to claim 9, wherein A security role field 801 consisting of a role security manager, a virtual user, and a system user; A control field 802 that stores control information used to control the process; A method for providing a virtual operating system environment using a secure kernel, comprising a category field 803 for each user, in which category information that can be distinguished for each user even in a root state is stored for the virtual user. The method of claim 1, The file system control sequence of step (f) is Checking whether the system call controller redirects the file system to the file system controller 106 and whether the redirect file is a redirection file (1001); Changing a path to a copied file if a redirect is declared as a file in a writable area (1002); Checking whether the file is in the command control list and stopping the process if the file is in the command control list (1003); If it is not a file in the command control list, collecting attribute information for the process and the filesystem to compare a filesystem access policy (1004); Method (1005) of providing a virtual operating system environment, characterized in that it comprises a step (1005) of checking whether the file system access policy violations with the collected information about the process and the file system. The method of claim 11, In step 1005, checking whether the file system access policy is violated. Allows only reads and executes for files in the system area, writes only for redirected files, If the file is in a user area, read, write, or execute is allowed only if the owner is the user. If the file is in another user area, access is denied. A method for providing a virtual operating system environment using a secure kernel, characterized in that a countermeasure such as stopping a process in the case of a violation of a file system access policy and executing an original system call if it is not violated.

Images