JP2016010031A - Remote integrity verification system, method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote integrity verification system, method and program for achieving integrity verification of platform, capable of detecting verification avoid attack of an attacker, without the premise of mounting a special hardware module.SOLUTION: In a remote integrity verification system 1, an integrity verification module 31 in a verification target device 30 determines whether or not it is started by start-up means 32. When a determination is made that it is not started by the start-up means 32, the integrity verification module 31 notifies the information indicating abnormal start, and when a determination is made that it is started by the start-up means 32, calculates the checksum of program code of the integrity verification module 31 itself, including a code based on a received random number information, and transmits to an integrity verification device 10. The integrity verification device 10 verifies the checksum thus received, and determines whether or not the verification target device 30 is integral.

Description

  The present invention relates to a remote integrity verification system, method and program.

  Conventionally, various methods have been proposed as security measures for computers. For example, Patent Documents 1 to 4 and Non-Patent Documents 1 to 5 are known.

  Patent Document 1 is a technique for verifying the integrity of software such as an OS and an application installed in a computer using a module installed in the computer device.

  Patent Document 2 is a technique for verifying the integrity of an application installed in an information processing apparatus such as a computer. The technology first verifies the integrity of the OS installed in the device based on a module that serves as the foundation of reliability verification (Root of Trust) such as TPM (Trust Platform Module) installed in the device. Do. Thereafter, the OS whose integrity has been verified verifies the integrity of the application, and the integrity of the application is guaranteed by starting the application in a form in which the integrity is guaranteed.

  Patent Document 3 is a technique for verifying the integrity of an OS installed in a computer device. By verifying the integrity of the BIOS, the boot loader, and the OS when the OS is shut down, processing related to verification at the time of restart is reduced and the startup speed is improved. Also in this technology, the reliability of integrity verification is left to special hardware such as ROM (Read Only Memory).

  Patent Document 4 discloses a technique for preventing impersonation of integrity verification due to leakage of a key by storing a key necessary for verifying the integrity of the OS of the device in a server device different from the device. It is.

  Non-Patent Document 1 and Non-Patent Document 2 are technologies for performing verification of platform software such as an OS in a verification target device using a software module installed in the platform software. The technology is composed of the software module and a verification server. When performing verification, first, a random number is transmitted from the verification server to the module. The module generates a verification signature from the random number, the code of the module itself, and the code of the verification signature generation function, and transmits the verification signature to the verification server. The module further generates a verification signature from the OS code using the verification signature generation function, and transmits the verification signature to the verification server. The verification server verifies the transmitted verification signature, and determines that the OS in the verification target device has not been falsified only when the signature has a correct value.

  Non-Patent Document 3 is a technique for verifying the integrity of an OS in a verification target device based on a software module. In the technology having a plurality of processors, countermeasures against an attack that avoids detection by an attacker using a plurality of processors to generate a verification signature spoofed before the module is implemented. .

  Non-Patent Document 4 is a technique for verifying virtual platform software (hypervisor) in a verification target apparatus using a hardware module mounted on the apparatus. Further, the technology realizes integrity verification by introducing a unique BIOS modified for verification into the verification target device.

  Non-Patent Document 5 is a technique for performing verification of an OS on a virtual environment by monitoring the OS in a hypervisor. This technology can perform correct verification only in an environment where there is a restriction on the attacker, for example, an attacker cannot tamper with a software module having the function of the technology.

Special table 2008-537224 JP 2010-182196 A JP 2012-32925 A JP 2011-3020 A

Seshadri, Arvind, Mark Luk, Elaine Shi, Adrian Perrig, Leendert van Doorn, and Pradeep Khosla. "Pioneer: verifying code integrity and encoding unexecuted code execution on legacy systems." In ACM SIGOPS Operating Systems Review, vol. 39, no. 5, pp. 1-16. ACM, 2005. Kovah, Xeno, Corey Kallenberg, Chris Weathers, Amy Herzog, Matthew Albin, and John Butterworth. “New results for Timing-Based attestation.” In Security and Privacy (SP), 2012 IEEE Symposium on, pp. 239-253. IEEE, 2012. Yan, Qiang, Jin Han, Yingjiu Li, Robert H. Deng, and Tieyan Li. "A software-based root-of-trust primitive on multicore platforms." In Proceedings of the 6th ACM Symposium on Information, Computer and Society. 334-343. ACM, 2011. Azab, Ahmed M. et al. , Peng Ning, Zhi Wang, Xuxian Jiang, Xiaolan Zhang, and Nathan C. et al. Skalsky. “HyperSentry: enabling treatment in-context measurement of hypervisor integrity,” In Proceedings of the 17th ACM conference on computer and commun. 38-49. ACM, 2010. Sharif, Monitor I. , Wenke Lee, Weidong Cui, and Andrea Lanzi. “Secure in-vm monitoring using hardware virtualization.” In Proceedings of the 16th ACM conference on commu- nications and communications, pp. 477-487. ACM, 2009.

However, Patent Document 1 to Patent Document 4 and Non-Patent Document 4 assume the use of a hardware module such as a TPM. Therefore, it cannot be applied to an apparatus not equipped with the module. In addition, when a cryptographic algorithm and a hash algorithm mounted on a hardware module are compromised and a vulnerability is found in the implementation of the module, the verification itself by the technology cannot be trusted. At that time, replacement of the module is necessary to maintain reliability, but this requires money and work costs such as purchase of a new module and replacement work.
In addition, Non-Patent Document 1 to Non-Patent Document 3 carry out integrity verification based on a module realized by software in view of the drawbacks of using the above hardware module. However, no countermeasure is taken against the case where an attacker performs the action of avoiding verification such as detecting the start of verification processing and hiding his attack code.
Furthermore, Non-Patent Document 5 is a technique that is effective only in an environment in which an attacker is restricted. Therefore, there is no resistance to an attacker who avoids the verification as described above and an attacker who falsifies the software module to be verified.

  Therefore, in view of the drawbacks of the conventional technology as described above, a system that realizes platform integrity verification capable of detecting an attacker's verification avoidance attack without assuming the installation of a special hardware module such as TPM. It has been demanded.

  It is an object of the present invention to provide a remote integrity verification system, method, and program for realizing platform integrity verification that can detect an attacker's verification avoidance attack without assuming the installation of a special hardware module. Objective.

Specifically, the following solutions are provided.
(1) A remote integrity verification system comprising an integrity verification module installed to operate in a verification target device that is a device to be verified, and an integrity verification device that verifies the integrity of the verification target device. The integrity verification apparatus includes request transmission means for transmitting an inspection request including random number information to be used for inspection to the verification target apparatus, and the verification target apparatus activates the integrity verification module. And the integrity verification module is activated by the activation unit and a branch information storage control unit that stores the branch information recorded when the activation unit activates the integrity verification module in the branch information storage unit. An activation determination unit that determines whether or not the information is based on the branch information stored in the branch information storage unit; If it is determined by the activation determination unit that there is not, an abnormal activation notification unit that notifies information indicating abnormal activation, and if the activation determination unit determines that the activation determination unit has been activated, the request transmission unit A request receiving unit that receives the check request transmitted by a checksum, and a checksum that calculates a checksum of the program code of the integrity verification module itself, including a code based on the random number information received by the request receiving unit A calculation unit, and an inspection information transmission unit that transmits the inspection information in the verification target device to the integrity verification device, and the inspection information transmission unit performs the abnormal activation notified by the abnormal activation notification unit. Or the check information including the checksum calculated by the checksum calculation unit to the integrity verification device. And the integrity verification device includes a test information receiving means for receiving the test information from the integrity verification module of the verification target device, and when the received test information includes information indicating abnormal activation, Inspection information determination means for determining that the verification target device is not complete, and checksum verification means for verifying the calculated checksum when the received inspection information includes the checksum, and The inspection information determination unit further determines whether or not the verification target device is complete based on the information verified by the checksum verification unit when the inspection information does not include information indicating abnormal activation. Remote integrity verification system.

  According to the configuration of (1), in the remote integrity verification system, the integrity verification device transmits an inspection request including random number information to be used for the inspection to the verification target device. Next, the verification target device activates the integrity verification module, and the integrity verification module stores the branch information recorded when the activation unit activates the integrity verification module in the branch information storage unit, and the activation unit Is determined based on the branch information stored in the branch information storage means. When the integrity verification module determines that it has not been activated by the activation means, it notifies the information indicating abnormal activation, and when it is determined that it has been activated by the activation means, it receives and receives the transmitted inspection request. The checksum of the program code of the integrity verification module itself including the code based on the random number information is calculated, and the inspection information including the calculated checksum is transmitted to the integrity verification device. The integrity verification device receives the inspection information from the integrity verification module of the verification target device, and determines that the verification target device is not complete when the received inspection information includes information indicating abnormal activation, and has received When the inspection information includes a checksum, the calculated checksum is verified, and it is further determined whether the verification target device is complete based on the verified information.

  Therefore, the remote integrity verification system according to (1) enables the detection of an attacker's verification avoidance attack without assuming the installation of a special hardware module, and realizes platform integrity verification.

  (2) The integrity verification device includes a time measuring unit that measures a time required from transmission of the inspection request by the inspection information transmitting unit to reception of the inspection information by the inspection information receiving unit, and the time measuring unit Required time determining means for determining whether or not the required time measured by is less than a predetermined value, wherein the inspection information determining means is based on the information verified by the checksum verification means The remote integrity verification according to (1), wherein when it is determined that the target device is complete, it is further determined whether or not the verification target device is complete based on the determination by the required time determination unit. system.

  Therefore, the remote integrity verification system according to (2) further determines the time required by the verification target device, thereby further enabling detection of an attacker's verification avoidance attack and realizing platform integrity verification.

  (3) The integrity verification module further includes a hash value calculation unit that calculates a hash value from a program code of a platform to be inspected, and the inspection information transmission unit is calculated by the hash value calculation unit. The hash value is further included in the inspection information and transmitted, and the integrity verification device further includes a hash value verification unit that verifies the hash value received by the inspection information reception unit, and the inspection information determination unit includes When it is determined that the verification target device is complete based on the determination by the required time determination unit, whether the verification target device is complete based on the information verified by the hash value verification unit The remote integrity verification system according to (2), wherein:

  Therefore, the remote integrity verification system according to (3) further enables detection of an attacker's verification avoidance attack by further determining the hash value calculated by the verification target device, thereby realizing platform integrity verification. To do.

  (4) The checksum calculation unit calculates the checksum based on the program code selected from the program codes of the integrity verification module itself based on random number information included in the check information. The remote integrity verification system according to any one of (3) to (3).

  Therefore, the remote integrity verification system according to (4) further enables detection of an attacker's verification avoidance attack by further determining the checksum value calculated by the selected program code, thereby enabling platform integrity verification. Realize.

  (5) The checksum calculation unit selects the branch information stored in the branch information storage unit based on random number information included in the check information, includes the selected branch information, and includes the checksum. The remote integrity verification system according to any one of (1) to (4), wherein:

  Therefore, the remote integrity verification system according to (5) further enables detection of an attacker's verification avoidance attack by further determining the checksum value calculated including the history information of the branch information, Achieve integrity verification.

  (6) A method executed by the remote integrity verification system according to (1), wherein in the integrity verification device, the request transmission means sends a verification request including random number information to be used for verification to the verification target A request transmitting step for transmitting to an apparatus; an activation step in which the activation means activates the integrity verification module in the verification target apparatus; and the branch information storage control unit in the integrity verification module; Branch information storage control step for storing the branch information recorded when starting the integrity verification module in the branch information storage means, and whether or not the start determination unit has been started by the start step. An activation determination step for determining based on the branch information stored in the storage means, and the abnormal activation notification unit includes the activation step. An abnormal activation notification step for notifying information indicating abnormal activation when the activation determination step determines that the request reception unit has been activated by the activation means. A request receiving step for receiving the inspection request transmitted by the request transmitting means, and the checksum calculator includes a code based on the random number information received by the request receiving step. A checksum calculation step for calculating a checksum of the program code of the integrity verification module itself, and information indicating abnormal start notified by the abnormal start notification step by the inspection information transmission unit, or the checksum calculation The test information including the checksum calculated by the step Transmitting to the integrity verification device; in the integrity verification device, the inspection information receiving means receives the inspection information from the integrity verification module of the verification target device; and the inspection information determination A means for determining that the verification target device is not complete when the received inspection information includes information indicating abnormal activation; and the checksum verification means A checksum verification step for verifying the calculated checksum when the checksum is included, and the checksum verification means when the inspection information determination means does not include information indicating abnormal activation. Further determining whether or not the verification target device is complete based on the information verified in the step; How to obtain.

  Therefore, the method according to (6) enables detection of an attacker's verification avoidance attack without presuming the installation of a special hardware module, thereby realizing platform integrity verification.

  (7) In the remote integrity verification system according to (1), a program for causing the computer of the integrity verification apparatus and the computer of the verification target apparatus to execute each step according to (6).

  Therefore, the program according to (7) can be executed by a computer to enable detection of an attacker's verification avoidance attack without assuming the installation of a special hardware module, thereby realizing platform integrity verification. Can be.

According to the present invention, it is possible to detect an attacker's verification avoidance attack without realizing the installation of a special hardware module such as a TPM, thereby realizing platform integrity verification.
That is, according to the present invention, an attack can be detected as follows.
(1) Even if an attacker attacks to alter the code of the integrity verification module, it can be detected by calculating and checking the checksum of the code of the integrity verification module.
(2) Even if an attacker attacks to alter the platform software code, it can be detected by calculating and checking the hash value of the platform software code.
(3) An attacker intervenes in the middle of the verification procedure by interrupt processing, rewriting the branch source address and branch destination address in the memory, tampers with it, hides the inserted code, and reloads the code into the memory after the verification procedure is completed Even if an attack is performed, it is possible to prevent the interruption from being involved in the verification procedure by disabling the interruption. In addition, it is possible to detect the presence of an attacker by calculating a checksum that takes into account the history information of the instruction branch. Further, it is possible to detect a delay in the required time caused by falsification by the inspection of the required time and concealment processing of the inserted code.
(4) Even if an attacker attacks the verification process by calculating the checksum in advance and sending it as a check result, the code used for the checksum calculation is calculated when the checksum is calculated. By selecting at random, pre-calculation becomes impossible.

It is a figure which shows the structure of the remote integrity verification system which concerns on one Embodiment of this invention. It is a figure which shows the structure of the integrity verification apparatus in the remote integrity verification system which concerns on one Embodiment of this invention. It is a figure which shows the structure of the integrity verification module in the remote integrity verification system which concerns on one Embodiment of this invention. It is a flowchart which shows the process of the remote integrity verification system which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a remote integrity verification system 1 according to an embodiment of the present invention. The remote integrity verification system 1 includes an integrity verification module 31 installed to operate in a verification target device 30 that is a device to be verified, and an integrity verification device 10 that verifies the integrity of the verification target device 30. Prepare. In the following embodiment, a hypervisor (virtualized environment platform software) is assumed as a platform to be verified.

FIG. 2 is a diagram showing a configuration of the integrity verification apparatus 10 in the remote integrity verification system 1 according to the embodiment of the present invention. FIG. 3 is a diagram showing a configuration of the integrity verification module 31 in the remote integrity verification system 1 according to an embodiment of the present invention.
The integrity verification apparatus 10 in the remote integrity verification system 1 includes an inspection information determination unit 111, a checksum verification unit 112, a time measurement unit 113, a required time determination unit 114, and a hash value verification as the inspection information verification unit 11. And a request transmission unit 121 and an inspection information reception unit 122 as the communication unit 12.
The verification target device 30 in the remote integrity verification system 1 includes an activation unit 32, and the integrity verification module 31 installed in the verification target device 30 includes a request reception unit 3131, a test information transmission unit 3132, and the communication unit 313. A branch information storage control unit 3111, an activation determination unit 3112, an abnormal activation notification unit 3113, and a checksum calculation unit 3114 as a self-verification information generation unit 311, and a hash as a platform verification information generation unit 312 A value calculation unit 3121, and a branch information storage unit 320.

  The integrity verification by the integrity verification apparatus 10 based on the branch information and checksum calculation information by the integrity verification module 31 will be described.

  The request transmission unit 121 of the integrity verification apparatus 10 transmits an inspection request including random number information used for the inspection to the verification target apparatus 30.

  The activation unit 32 of the verification target device 30 activates the integrity verification module 31. Specifically, for example, in the case of a configuration using a serial cable as a communication medium between the verification target device 30 and the integrity verification device 10, the activation unit 32 generates an interrupt generated by receiving an inspection request via the serial cable. The integrity verification module 31 registered as a handler is activated.

  The branch information storage control unit 3111 of the integrity verification module 31 uses the branch information (for example, the address information of the branch source record and the branch destination record) recorded when the activation unit 32 activates the integrity verification module 31 as branch information. The data is stored in the storage unit 320. Specifically, the branch information storage control unit 3111 stores, for example, the last branch record mounted in the CPU architecture as an instruction branch history information (for example, an LBR (Last Branch Record) mechanism). ), The branch information storage means 320 stores the instruction branch history information as branch information.

  The activation determination unit 3112 of the integrity verification module 31 determines whether or not it has been activated by the activation unit 32 based on the branch information stored in the branch information storage unit 320 (for example, the address information of the branch source record and the branch destination record). judge. Specifically, the activation determination unit 3112 determines the branch source and branch destination of the newest branch based on the information stored in the branch information storage unit 320 that is the history information of the instruction branch after the integrity verification module 31 is activated. With reference to the address information, it is determined whether or not the integrity verification module 31 has been activated by receiving a test request.

  The abnormal activation notification unit 3113 of the integrity verification module 31 is abnormal when it is determined by the activation determination unit 3112 that it has not been activated by the activation unit 32 (for example, activated by a trigger other than reception of the inspection request). Notify information indicating activation.

  The request reception unit 3131 of the integrity verification module 31 receives the inspection request transmitted by the request transmission unit 121 of the integrity verification apparatus 10 when it is determined by the activation determination unit 3112 that it has been activated by the activation unit 32.

  The integrity verification module 31 may invalidate all the interrupts of the verification target device 30 when it is determined by the activation determination unit 3112 that it has been activated by the activation unit 32. For example, interrupts that can be masked are set to be disabled (Disable), and interrupts that cannot be masked (NMI: Non-Maskable Interrupt) are changed to be handled by another software. It may be possible not to migrate.

  The checksum calculator 3114 of the integrity verification module 31 calculates the checksum of the program code of the integrity verification module 31 itself, including the code based on the random number information received by the request receiver 3131. Note that the integrity verification module 31 may be loaded into a fixed address and operated in the verification target device 30. When the integrity verification module 31 is loaded and operated at a variable address in the verification target device 30, it is possible to restore the state in which the integrity verification module 31 is loaded in the integrity verification device 10.

  At that time, the checksum calculator 3114 may calculate the checksum based on the program code selected from the program codes of the integrity verification module 31 itself based on the random number information included in the inspection information. Specifically, the checksum calculation unit 3114, based on the random number information transmitted from the integrity verification device 10, for example, when the random number information is 5bf... The 11th code from the code and the 15th code from the code may be selected at random. The checksum calculation unit 3114 repeatedly executes a checksum calculation based on the selected code, including a random selection based on random number information, a predetermined number of times to obtain a final checksum.

Further, the checksum calculation unit 3114 may add the instruction branch history information to the checksum calculation. That is, the checksum calculator 3114 selects the branch information stored in the branch information storage unit 320 based on the random number information included in the check information, and calculates the checksum including the selected branch information.
For example, the checksum calculation unit 3114 determines whether to add the instruction branch history information to the checksum calculation at the beginning of each iterative process in the checksum calculation. The checksum calculation unit 3114 makes this determination based on the random number information. When adding the instruction branch history information to the checksum calculation, the checksum calculation unit 3114 randomly selects history information to be added to the calculation from the branch information storage unit 320 based on the random number information (for example, the random number information is In the case of 5bf..., The fifth latest branch information is selected based on “5” that is the first value among the values within the number of stored branch information (for example, 16). Then, the checksum calculation unit 3114 calculates a checksum from the selected branch information and the code separately selected as described above.

  The inspection information transmission unit 3132 transmits information indicating the abnormal activation notified by the abnormal activation notification unit 3113 or inspection information including the checksum calculated by the checksum calculation unit 3114 to the integrity verification apparatus 10.

  The inspection information receiving unit 122 of the integrity verification apparatus 10 receives inspection information from the integrity verification module 31 of the verification target apparatus 30.

  The inspection information determination unit 111 of the integrity verification apparatus 10 determines that the verification target apparatus 30 is not complete when the received inspection information includes information indicating abnormal activation.

  The checksum verification means 112 of the integrity verification apparatus 10 verifies the calculated checksum when the received inspection information includes a checksum. Specifically, the checksum verification unit 112 restores the checksum calculation process executed by the integrity verification module 31 from the random number information transmitted by the request transmission unit 121 and the code of the integrity verification module 31. And calculate the checksum. Then, the checksum verification unit 112 collates the checksum value calculated by restoration with the inspection information transmitted from the integrity verification module 31 as verification information.

  The inspection information determination unit 111 of the integrity verification device 10 is that the verification target device 30 is complete based on the information verified by the checksum verification unit 112 when the inspection information does not include information indicating abnormal activation. It is further determined whether or not. Specifically, the check information determination unit 111, when the checksum information calculated by the checksum verification unit 112 and the checksum information transmitted by the integrity verification module 31 match, Is determined to be complete.

  Furthermore, the verification of integrity by the integrity verification device 10 based on the response time from the verification target device 30 will be described.

  The time measuring unit 113 measures the time required from the transmission of the inspection request by the inspection information transmitting unit to the reception of the inspection information by the inspection information receiving unit 122.

  The required time determination unit 114 determines whether the required time measured by the time measurement unit 113 is smaller than a predetermined value. Specifically, the required time determination unit 114 compares the required time with a predetermined value, and when the difference is within a predetermined range (for example, when the difference ≦ predetermined value ± predetermined range), the required time It is determined that the value is smaller than the predetermined value.

  When the inspection information determination unit 111 determines that the verification target device 30 is complete based on the information verified by the checksum verification unit 112, the inspection information determination unit 111 further determines the verification target device based on the determination by the required time determination unit 114. It is determined whether 30 is complete.

  Further, the verification of integrity by the integrity verification device 10 based on the hash value calculation by the integrity verification module 31 will be described.

  The hash value calculation unit 3121 of the integrity verification module 31 calculates a hash value from the program code of the platform to be inspected. Specifically, the hash value calculation unit 3121 calculates a hypervisor hash value (for example, a hash value based on the hypervisor code). The hash value calculation unit 3121 calculates a hash value using a hash function such as SHA-1.

The inspection information transmission unit 3132 further transmits the hash value calculated by the hash value calculation unit 3121 in the inspection information.
The hash value verification unit 115 of the integrity verification apparatus 10 verifies the hash value received by the inspection information reception unit 122. Specifically, the hash value verification unit 115 collates the hash value included in the received inspection information with the verification hash value included in the platform verification information held in the integrity verification apparatus 10.
When it is determined that the verification target device 30 is complete based on the determination by the required time determination unit 114, the inspection information determination unit 111 further performs verification based on the information verified by the hash value verification unit 115. It is determined whether the device 30 is complete.
When the collation by the hash value verification unit 115 matches, the inspection information determination unit 111 determines that the hypervisor is not attacked and determines that the verification target device 30 is complete.

  FIG. 4 is a flowchart showing processing of the remote integrity verification system 1 according to an embodiment of the present invention. In the remote integrity verification system 1 according to an embodiment of the present invention, the integrity verification device 10 is configured by hardware included in a computer and its peripheral devices, and software that controls the hardware. A unit (for example, CPU) is a process executed according to predetermined software under the OS. The integrity verification module 31 is installed in the verification target device 30 including a computer and its peripheral devices, and the following processing is processing executed by a control unit (for example, CPU) of the verification target device 30.

  In step S <b> 101, the CPU (request transmission unit 121) of the integrity verification apparatus 10 transmits an inspection request including random number information used for the inspection to the verification target apparatus 30.

  In step S <b> 201, the CPU (starting unit 32) of the verification target device 30 starts the integrity verification module 31.

  In step S <b> 301, the integrity verification module 31 (the branch information storage control unit 3111, the activation determination unit 3112, the abnormal activation notification unit 3113, and the examination information transmission unit 3132) is activated when the activation unit 32 activates the integrity verification module 31. The recorded branch information (for example, the address information of the branch source record and the branch destination record) is stored in the branch information storage unit 320, and the branch information stored in the branch information storage unit 320 as to whether or not it has been started by the start unit 32 The determination is made based on (for example, address information of the branch source record and the branch destination record). If the determination is YES, the CPU moves the process to step S302. If the determination is NO, the CPU transmits inspection information including information indicating abnormal activation to the integrity verification apparatus 10 and the integrity verification module 31. The process of the remote integrity verification system 1 proceeds to step S102 of the integrity verification apparatus 10. In step S102, the integrity verification apparatus 10 (inspection information determination unit 111) receives the inspection information, and determines that the verification target apparatus 30 is not complete when the received inspection information includes information indicating abnormal activation. Then, the verification target device 30 is notified that it is under attack, and the process is terminated.

  In step S302, the integrity verification module 31 (request reception unit 3131) receives the transmitted inspection request, invalidates the interrupt of the verification target device 30, and prevents the processing from being transferred to another software.

  In step S303, the integrity verification module 31 (checksum calculation unit 3114) calculates the checksum of the program code of the integrity verification module 31 itself including the code based on the random number information received by the request reception unit 3131. .

  In step S <b> 304, the integrity verification module 31 (the inspection information transmission unit 3132) transmits the inspection information including the checksum calculated by the checksum calculation unit 3114 to the integrity verification apparatus 10.

  In step S305, the integrity verification module 31 (hash value calculation unit 3121) calculates a hash value from the program code of the platform to be inspected.

  In step S <b> 306, the integrity verification module 31 (the inspection information transmission unit 3132) transmits the inspection information including the hash value calculated by the hash value calculation unit 3121 to the integrity verification apparatus 10.

  In step S <b> 103, the CPU (inspection information receiving unit 122) of the integrity verification apparatus 10 receives inspection information including a checksum value from the integrity verification module 31 of the verification target apparatus 30.

  In step S <b> 104, the CPU (inspection information receiving unit 122) of the integrity verification apparatus 10 receives inspection information including a hash value from the integrity verification module 31 of the verification target apparatus 30.

  In step S105, the CPU (checksum verification unit 112, inspection information determination unit 111) of the integrity verification apparatus 10 restores the checksum calculation process executed by the integrity verification module 31, and receives the checksum. Checked against checksum. If the collation results match (if YES), the CPU moves the process to step S106. If the collation results do not match (NO), the CPU determines that the verification target device 30 is not complete. Then, the verification target device 30 is notified that it is under attack, and the process is terminated.

  In step S106, the CPU (time measurement unit 113, required time determination unit 114, inspection information determination unit 111) of the integrity verification apparatus 10 starts when the inspection request is transmitted in step S101 and ends when it is received in step S103. It is determined whether or not the measurement time by the time measurement is smaller than a predetermined value. If this determination is YES, the CPU moves the process to step S107. If this determination is NO, the CPU determines that the verification target device 30 is not complete, and the verification target device 30 is under attack. The process is terminated.

  In step S <b> 107, the CPU (hash value verification unit 115, inspection information determination unit 111) of the integrity verification apparatus 10 includes the hash value included in the received inspection information and the platform verification information held in the integrity verification apparatus 10. Is compared with the verification hash value included in. If the verification results do not match (in the case of NO), the CPU determines that the verification target device 30 is not complete, informs that the verification target device 30 is under attack, ends the processing, and performs verification. If the results match (YES), the CPU determines that the verification target device 30 is complete, informs that the verification target device 30 is not under attack, and ends the process.

According to the present embodiment, in the remote integrity verification system 1, the integrity verification device 10 transmits an inspection request including random number information to be used for inspection to the verification target device 30. Next, the verification target device 30 activates the integrity verification module 31, and the integrity verification module 31 stores the branch information recorded when the activation unit 32 activates the integrity verification module 31 with the branch information storage unit 320. And whether or not it has been activated by the activation means 32 is determined based on the branch information stored in the branch information storage means 320. When the integrity verification module 31 determines that the activation means 32 has not been activated, the integrity verification module 31 notifies information indicating abnormal activation, and the integrity verification device 10 determines that the verification target device 30 is not complete. When the integrity verification module 31 determines that it has been activated by the activation means 32, the integrity verification module 31 receives the transmitted inspection request and checks the program code of the integrity verification module 31 itself including the code based on the received random number information. The sum is calculated, and the inspection information including the calculated checksum is transmitted to the integrity verification apparatus 10. The integrity verification apparatus 10 receives the inspection information from the integrity verification module 31 of the verification target apparatus 30, verifies the received checksum, and determines whether the verification target apparatus 30 is complete based on the verified information. Determine.
Furthermore, when the integrity verification apparatus 10 determines that the verification target apparatus 30 is complete based on the information verified by the checksum, the measured required time from the transmission of the inspection request to the reception of the inspection information. It is determined whether or not the value is smaller than a predetermined value, and it is determined whether or not the verification target device 30 is complete.
Furthermore, the integrity verification device 10 verifies the hash value calculated from the program code of the platform by the integrity verification module 31 when it is determined that the verification target device 30 is complete based on the determination by the required time. Then, it is determined whether the verification target device 30 is complete.
Therefore, the remote integrity verification system 1 can detect an attacker's verification avoidance attack without assuming the installation of a special hardware module, and can realize platform integrity verification.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to embodiment mentioned above. The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

  For example, in this embodiment, after verifying the verification target device 30 with the checksum, the verification target device 30 is verified with the hash value. However, after verifying the verification target device 30 with the hash value, the verification target device with the checksum is performed. 30 may be verified.

DESCRIPTION OF SYMBOLS 1 Remote integrity verification system 10 Integrity verification apparatus 11 Inspection information verification means 111 Inspection information determination means 112 Checksum verification means 113 Time measurement means 114 Time required determination means 115 Hash value verification means 12 Communication means 121 Request transmission means 122 Inspection information Receiving means 30 Verification target device 31 Integrity verification module 311 Self-verification information generation unit 3111 Branch information storage control unit 3112 Activation determination unit 3113 Abnormal activation notification unit 3114 Checksum calculation unit 312 Platform verification information generation unit 3121 Hash value calculation unit 313 Communication Unit 3131 request receiving unit 3132 examination information transmitting unit 320 branch information storage unit 32 activation unit

Claims (7)

A remote integrity verification system comprising an integrity verification module installed to operate on a verification target device that is a device to be verified, and an integrity verification device for verifying the integrity of the verification target device,
The integrity verification device comprises:
A request transmission means for transmitting an inspection request including random number information to be used for inspection to the verification target device;
The verification target device is:
Activating means for activating the integrity verification module;
The integrity verification module is
A branch information storage control unit for storing branch information recorded when the activation unit activates the integrity verification module in a branch information storage unit;
An activation determination unit that determines whether the activation is performed by the activation unit based on the branch information stored in the branch information storage unit;
An abnormal activation notifying unit for notifying information indicating abnormal activation when the activation determining unit determines that the activation means is not activated;
A request receiving unit that receives the inspection request transmitted by the request transmitting unit when the activation determining unit determines that the activation is activated by the activation unit;
A checksum calculator that calculates a checksum of the program code of the integrity verification module itself, including a code based on the random number information received by the request receiver;
An inspection information transmission unit that transmits inspection information in the verification target device to the integrity verification device;
The inspection information transmission unit transmits information indicating abnormal activation notified by the abnormal activation notification unit or the inspection information including the checksum calculated by the checksum calculation unit to the integrity verification device. ,
The integrity verification device comprises:
Inspection information receiving means for receiving the inspection information from the integrity verification module of the verification target device;
When the received inspection information includes information indicating abnormal activation, inspection information determination means for determining that the verification target device is not complete,
Checksum verification means for verifying the calculated checksum when the received check information includes the checksum;
The inspection information determination unit further determines whether or not the verification target device is complete based on the information verified by the checksum verification unit when the inspection information does not include information indicating abnormal activation. judge,
Remote integrity verification system. The integrity verification device comprises:
Time measuring means for measuring a time required from transmission of the inspection request by the inspection information transmitting section to reception of the inspection information by the inspection information receiving means;
A required time determining means for determining whether the required time measured by the time measuring means is smaller than a predetermined value;
When the inspection information determination unit determines that the verification target device is complete based on the information verified by the checksum verification unit, the verification information determination unit further determines the verification target based on the determination by the required time determination unit Determine if the device is complete,
The remote integrity verification system of claim 1. The integrity verification module is
A hash value calculator for calculating a hash value from the program code of the platform to be inspected;
The inspection information transmission unit further includes the hash value calculated by the hash value calculation unit and transmits the inspection information,
The integrity verification device comprises:
A hash value verification unit that verifies the hash value received by the inspection information reception unit;
The inspection information determination unit, when it is determined that the verification target device is complete based on the determination by the required time determination unit, and further, based on the information verified by the hash value verification unit Determine whether the target device is complete,
The remote integrity verification system of claim 2.   The checksum calculation unit calculates the checksum based on a program code selected from among program codes of the integrity verification module itself based on random number information included in the check information. The remote integrity verification system according to any one of the above. The checksum calculation unit is based on random number information included in the inspection information.
The remote integrity verification system according to any one of claims 1 to 4, wherein the branch information stored in the branch information storage unit is selected, and the checksum is calculated including the selected branch information. . A method performed by the remote integrity verification system of claim 1, comprising:
In the integrity verification device,
A request transmitting step in which the request transmitting means transmits an inspection request including random number information to be used for inspection to the verification target device;
In the verification target device,
An activation step in which the activation means activates the integrity verification module;
In the integrity verification module,
A branch information storage control step, wherein the branch information storage control unit stores the branch information recorded when the starter starts the integrity verification module in the branch information storage;
An activation determination step for determining whether the activation determination unit is activated in the activation step based on the branch information stored in the branch information storage unit;
An abnormal activation notification step of notifying information indicating an abnormal activation when the abnormal activation notification unit is not activated by the activation step and determined by the activation determination step;
A request receiving step for receiving the inspection request transmitted by the request transmitting means when the request determining section determines that the activation determining section has activated the request receiving section;
A checksum calculation step in which the checksum calculation unit calculates a checksum of the program code of the integrity verification module itself including a code based on the random number information received by the request reception step;
The inspection information transmitting unit transmits information indicating abnormal activation notified by the abnormal activation notification step or the inspection information including the checksum calculated by the checksum calculation step to the integrity verification device. Steps,
In the integrity verification device,
A test information receiving step in which the test information receiving means receives the test information from the integrity verification module of the verification target device;
When the inspection information determination means includes information indicating abnormal activation, the inspection information determination step for determining that the verification target device is not complete,
A checksum verification step in which the checksum verification means verifies the calculated checksum when the received check information includes the checksum;
The inspection information determination means further determines whether the verification target device is complete based on the information verified by the checksum verification step when the inspection information does not include information indicating abnormal activation. Determining.   7. The program for causing a computer of the integrity verification apparatus and a computer of the verification target apparatus to execute each step according to claim 6 in the remote integrity verification system according to claim 1.

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