WO2021208354A1

WO2021208354A1 - Apparatus and method for performing trusted measurement by introducing external hardware root of trust

Info

Publication number: WO2021208354A1
Application number: PCT/CN2020/115906
Authority: WO
Inventors: 方昊; 吴鹤意
Original assignee: 南京东科优信网络安全技术研究院有限公司
Priority date: 2020-04-16
Filing date: 2020-09-17
Publication date: 2021-10-21
Also published as: CN111538993B; CN111538993A

Abstract

An apparatus and method for performing trusted measurement by introducing an external hardware root of trust. The apparatus comprises a universal serial bus supervision unit, a trusted computing module driving unit, a trusted computing module and a flash memory read-write unit, wherein the universal serial bus supervision unit is upwardly-docked with a universal serial bus interface of a computer, and is downwardly-connected to the trusted computing module driving unit and the flash memory read-write unit; and the trusted computing module driving unit is also connected to the trusted computing module. According to the apparatus and method, a USB interface serves as a communication interface between a trusted computing module and a computer, and an implementation means for key technology of connecting a host to a core root trusted measurement module and the trusted computing module in a USB manner is provided, such that the application field of trusted computing is no longer limited to new computers and new operating systems, but is also applicable to old computers which do not take trusted technology into consideration when being designed, thereby expanding the application range of trusted computing technology.

Description

Device and method for introducing external hardware root of trust for credibility measurement

Technical field

The present invention relates to information security technology, in particular to a device and method for introducing an external hardware root of trust for credibility measurement.

Background technique

Trusted computing, as an active defense technology, does not need to rely on virus database upgrades and can automatically be immune to new security threats such as ransomware, advertising Trojans, and mining machines. Trusted computing generally requires a trusted computing module (TPM/TCM) and a core root trust measurement module (CRTM) to be attached to the motherboard.

The core root trust measurement module is generally implemented in two ways: one is for embedded hardware (such as routers, mobile phones), the basic boot program is directly solidified in the read-only memory on the motherboard, and the CPU is powered on according to the jumper settings. Directly run the basic boot program in the read-only memory; one is to use UEFI with the SecureBoot function of the motherboard to verify the signature on the system based on UEFI boot, and the motherboard will verify the boot program, and then proceed to the subsequent boot process after the verification is passed. .

The trusted computing module generally refers to the international standard TPM (Trusted Platform Module) or the national secret standard TCM (Trusted Cryptographic Module). Both need to be embedded in the motherboard and connected by LPC bus, I2C bus or SPI bus. The LPC bus, I2C bus or SPI bus of the ordinary motherboard is directly connected to the CPU, and there is no interface left outside for users to plug in.

As mentioned above, trusted computing requires hardware support from both the trusted computing module and the core root trust measurement module, and the general implementation of these two key hardware for trusted computing is closely tied to the motherboard design.

On the other hand, old computer systems are facing severe security threats-old computer systems often run professional software that has been running stably in the past few years, and the basic system (such as Windows XP, etc.) that runs these professional software is no longer provided by the manufacturer. Upgrade and maintenance, and potential system vulnerabilities are constantly discovered by information security attackers. Most of the existing old computer systems do not have hardware-level trusted computing function support, or use relatively backward trusted computing hardware. And because the old computer systems of industry users often run professional software and take on key roles, they cannot update to the latest system or simply replace the hardware at will. Therefore, there needs to be a way to introduce New trusted hardware.

Summary of the invention

Objective of the invention: The present invention aims at the problem of accessing trusted hardware and exerting trusted computing functions on computers that did not consider trusted computing hardware in the original design, and provides a device and method for introducing an external hardware root of trust for trust measurement .

Technical solution: In order to achieve the above-mentioned purpose of the invention, the present invention adopts the following technical solutions:

The device described in the present invention introduces an external hardware root of trust for credibility measurement, which includes a universal serial bus monitoring unit, a trusted computing module drive unit, a trusted computing module, and a flash memory read-write unit. Among them, the universal serial bus supervisory unit is connected to the universal serial bus interface (ie, USB interface) of the computer upwards, and the trusted computing module drive unit and the flash memory read-write unit are connected downwards. The trusted computing module driving unit is connected to the trusted computing module.

The universal serial bus supervisory unit includes a memory, a processor, and a computer program stored on the memory and running on the processor. When the processor executes the program, it realizes: monitors the universal serial bus data flow, and reads the data on the bus. Fetch and write signals for analysis, arbitration and forwarding. Among them, the "analysis" function is analyzed in this unit according to the universal serial bus protocol standard, and the "arbitration" function extracts the reading and writing direction and address information of the bus signal as verification information The two-tuple is sent to the trusted computing module driving unit and waiting for its feedback, and arbitrating whether to forward or not according to the feedback. The "forwarding" function forwards the signal marked as a preset specific address to the trusted computing module driving unit to arbitrate Other permitted non-preset specific address signals are forwarded to the flash memory read/write unit, and the universal serial bus signals fed back by the trusted computing module drive unit and the flash memory read/write unit are fed back to the connected host universal serial bus interface.

The trusted computing module driving unit includes a memory, a processor, and a computer program that is stored on the memory and can run on the processor. When the processor executes the program, it realizes: receiving verification information generated by the universal serial bus supervisory unit 2. Tuple, and read the preset specific address information and the state register information of the trusted computing module, and feed back the verification information to the universal serial bus supervision unit; receive the specific information forwarded by the universal serial bus supervision unit The signal of the address is converted into a signal specified by the trusted computing module communication protocol, and then transferred to the trusted computing module, and then the signal fed back by the trusted computing module is converted into a signal specified by the universal serial bus protocol, and then transmitted back to the universal serial Bus supervision unit.

The flash memory read-write unit is a USB flash memory read-write module and a flash memory particle chip commonly used in the market, and is introduced as a necessary component of the device as a whole. The unit operates without modification in accordance with the Universal Serial Bus standard. The flash memory read-write unit also includes a computer program that can be run on the processor of the user's host. When the processor executes the program, it implements: loading and executing the device driver, loading and executing the host disk driver, and loading and executing the credibility measurement program (The program that performs trusted verification on the boot program of the user host and configures the state of the trusted computing module according to the trusted computing standard). The trusted measurement program uses the device driver to send a signal to the universal serial bus supervisory unit, and then through the trusted computing module to drive the unit, after passing the verification, the user host's processor control will be handed over to the original boot on the user host's disk The program completes the computer startup.

The trusted computing module refers to a trusted computing module chip that conforms to the TPM standard or the TCM standard, and is introduced as a necessary component of the device as a whole. The unit operates without modification according to the TPM standard or the TCM standard.

A method for introducing an external hardware root of trust for trust measurement, which specifically includes the following steps:

(1) Configure a specific address in the universal serial bus supervisory unit in advance.

(2) Configure a specific address in the trusted computing module drive unit in advance.

(3) Pre-set the startup mode in the user host as USB, insert the device into the user host's universal serial bus interface and power on, the device is read by the user host, through the universal serial bus supervisory unit and flash memory read-write unit , The program stored in the flash memory read-write unit is read by the processor of the user host.

(4) The device driver stored in the flash memory read-write unit is executed.

(5) The user host disk driver program stored in the flash memory read-write unit is executed, so that the original boot program on the user host disk is read into the user host memory, and the device driver program in step 4 is passed through the universal serial The bus supervision unit, the trusted computing module drive unit, and the trusted computing module perform integrity measurement that meets the trusted standard.

(6) The device feeds back the measurement result to the user host. If it passes the measurement, it continues to execute the original boot program of the user host to realize the trusted measurement function; if it does not pass, it alarms and stops the user host startup process.

Beneficial effects: Compared with the prior art, the present invention uses a universal USB interface as the communication interface between the trusted computing module and the computer, and provides that the connection between the host and the core root trust metric module and the trusted computing module is realized in a USB manner The realization of the key technology of the trusted computing technology makes the application field of trusted computing no longer limited to new computers and new operating systems, but is suitable for computers that did not consider trusted technology in the old design, which expands the scope of application of trusted computing technology. .

Description of the drawings

Figure 1 is a schematic diagram of the structure of the device of the present invention.

Detailed ways

The technical solution of the present invention will be described in detail below with reference to the drawings and specific embodiments. The following are only preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, especially for universal strings. The selection of the specific technology used in the implementation of the line bus supervision unit (such as the choice of FPGA implementation or embedded chip implementation, etc.). Changes in these details will not affect the overall architecture of the present invention. Therefore, these changes, improvements and modifications should also be regarded as The scope of protection of the present invention.

As shown in Figure 1, the device includes a universal serial bus supervision unit, a trusted computing module drive unit, a trusted computing module, and a flash memory read-write unit. Among them, the universal serial bus supervisory unit is connected to the universal serial bus interface (ie, USB interface) of the user host upwards, and the trusted computing module drive unit and the flash memory read-write unit are connected downwards. The trusted computing module driving unit is connected to the trusted computing module.

The universal serial bus supervisory unit includes a memory, a processor, and a computer program stored on the memory and running on the processor. When the processor executes the program, it realizes: monitors the universal serial bus data flow, and reads the data on the bus. Fetch and write signals for analysis, arbitration and forwarding. Among them, the "analysis" function is analyzed in this unit according to the universal serial bus protocol standard, and the "arbitration" function extracts the reading and writing direction and address information of the bus signal as verification information The two-tuple is sent to the trusted computing module driving unit and waiting for its feedback, and arbitrating whether to forward or not according to the feedback. The "forwarding" function forwards the signal marked as a preset specific address to the trusted computing module driving unit to arbitrate Other permitted non-preset specific address signals are forwarded to the flash memory read/write unit, and the universal serial bus signals fed back by the trusted computing module drive unit and flash memory read/write unit are fed back to the universal serial bus interface of the connected user host .

The flash memory read-write unit is a USB flash memory read-write module and a flash memory particle chip commonly used in the market, and is introduced as a necessary component of the device as a whole. The unit operates without modification in accordance with the Universal Serial Bus standard. The flash memory read-write unit also includes a computer program that can run on the processor of the user's host. When the processor executes the computer program, it implements: loading and executing the device driver, loading and executing the host disk driver, loading and executing the trustworthiness measurement Program (a program that performs trusted verification on the boot program of the user host and configures the state of the trusted computing module according to the trusted computing standard). The trusted measurement program uses the device driver to send a signal to the universal serial bus supervisory unit, and then through the trusted computing module to drive the unit, after passing the verification, the user host's processor control will be handed over to the original boot on the user host's disk The program completes the computer startup. Since the write operation to the specific address of the flash memory read/write unit is controlled by the universal serial bus supervision unit and the trusted computing module drive unit, the core root trust measurement module is the device driver and host at the specific address in the flash memory read/write unit. Disk driver and trust measurement program.

The trusted computing module refers to a trusted computing module chip that complies with the TPM standard or the TCM standard, and is introduced as a necessary component of the device as a whole. The unit operates without modification according to the TPM standard or the TCM standard.

In the traditional trusted computing system, the trusted computing module is connected to the user host by the LPC or SPI bus. From the perspective of the user host, the trusted computing module is a device on the LPC bus or a device on the SPI bus. This is a direct the process of. However, the motherboard does not plan the LPC bus interface or the SPI bus interface (generally, the LPC bus and the SPI bus are always directly connected to the corresponding devices on the PCB board with wires, and there is no standard interface, so the motherboard does not plan the LPC bus interface or SPI bus. When the interface is normal), the device monitors the signals on the universal serial bus through the universal serial bus monitoring unit, thereby providing the trusted computing module and the core root trust measurement module with a unified USB interface for the host user to call. At the same time, the universal serial bus supervisory unit and the trusted computing module drive unit verify the status of the two-tuple and the trusted computing module, and also ensure that the boot root is not threatened by illegal tampering.

The following is a detailed description of the process of realizing trusted startup through this device:

Step 1: Configure a specific address in the universal serial bus supervisory unit in advance. The specific address is used by the universal serial bus supervisory unit to intercept the specific universal serial bus request and transform it into a trusted computing module request via the trusted computing module driving unit.

Step 2: Configure a specific address in the trusted computing module drive unit in advance. The specific address is used to determine whether the specified address is writable in combination with the trusted computing module status, and is used to implement the core root trust measurement module in the flash memory read-write unit. The specific address is consistent with the addresses of the "driver of this device", "driver of the host disk" and "trusted measurement program" in the flash memory read-write unit.

Step 3: Pre-set the startup mode in the user host as USB, insert the device into the universal serial bus interface of the user host and power on, the device is read by the user host, through the universal serial bus supervisory unit and flash memory read-write unit , The program stored in the flash memory read-write unit is read by the processor of the user host.

Step 4: The device driver stored in the flash memory read-write unit is executed. This driver is used to provide the calling interface of the boot root and trusted root to the host user.

Step 5: The user host disk driver stored in the flash memory read-write unit is executed, so that the original boot program on the user host disk is read into the user host memory, and the device driver in step 4 is passed through the universal serial The bus supervision unit, the trusted computing module drive unit, and the trusted computing module perform integrity measurement that meets the trusted standard.

Step 6: The device feeds back the measurement result to the user host. If it passes the measurement, it continues to execute the original boot program of the user host to realize the trusted measurement function; if it does not pass, it alarms and stops the user host startup process.

Claims

A device that introduces an external hardware root of trust for credibility measurement, which is characterized in that it includes a universal serial bus monitoring unit, a trusted computing module drive unit, a trusted computing module, and a flash memory read-write unit, wherein the universal serial bus monitors The unit is connected with the universal serial bus interface of the computer upwards, and connected with the trusted computing module drive unit and the flash memory read-write unit, and the trusted computing module drive unit is connected with the trusted computing module.
The device for introducing an external hardware root of trust for trust measurement according to claim 1, wherein the universal serial bus supervisory unit includes a first memory, a first processor, and a device stored on the first memory and The first computer program running on the first processor, when the first processor executes the first computer program, it realizes: monitor the universal serial bus data flow, analyze the read and write signals on the universal serial bus, Arbitration and forwarding, in which the "analysis" function is analyzed in this unit according to the universal serial bus protocol standard; the "arbitration" function extracts the reading and writing direction and address information of the bus signal into a two-tuple of verification information and sends it to trusted computing The module drive unit waits for its feedback, and arbitrates whether to forward or not according to the feedback; the "forward" function forwards the signal marked as a preset specific address to the trusted computing module drive unit, and arbitrates other non-preset specific addresses permitted by the arbitration The signal is forwarded to the flash memory read-write unit, and the universal serial bus signal fed back by the trusted computing module drive unit and the flash memory read-write unit is fed back to the connected host universal serial bus interface.
The device for introducing an external hardware root of trust for trust measurement according to claim 1, wherein the trusted computing module driving unit includes a second memory, a second processor, and a device stored on the second memory and A second computer program running on the second processor. When the second processor executes the program, it realizes: receiving the verification information two-tuple generated by the universal serial bus supervision unit, and reading the preset specific address information and the The information of the state register of the trusted computing module is fed back to the universal serial bus supervisory unit; the signal of the specific address forwarded by the universal serial bus supervisory unit is received and converted into the trusted computing module communication protocol. The specified signal is passed to the trusted computing module, and the signal fed back by the trusted computing module is converted into a signal specified by the universal serial bus protocol, and then transmitted back to the universal serial bus supervisory unit.
The device for introducing an external hardware root of trust for credibility measurement according to claim 1, wherein the flash memory read-write unit includes a USB flash memory read-write module and a flash memory particle chip, and the unit operates according to the universal serial bus standard , The flash memory read-write unit also includes a third computer program that can be run on the processor of the user host, when the processor of the user host executes the third computer program: load and execute the device driver, load and execute the host disk drive Program, load and execute the trusted measurement program; the trusted measurement program uses the device driver to send a signal to the universal serial bus supervision unit, and then drives the unit through the trusted computing module, and after verification, the user host’s processor The control right is handed over to the original boot program on the user host disk to complete the computer startup; because the write operation to the specific address of the flash memory read and write unit is controlled by the universal serial bus supervision unit and the trusted computing module drive unit, the core root trust measurement module is The device driver, host disk driver and trusted measurement program at a specific address in the flash memory read-write unit.
The device for introducing an external hardware root of trust for trust measurement according to claim 1, wherein the trusted computing module is a trusted computing module chip that complies with the TPM standard or the TCM standard.
Based on any one of the above claims 1-5, the method for measuring the trustworthiness of a device that introduces an external hardware root of trust for trustworthiness measurement is characterized in that it comprises the following steps:

(1) Configure a specific address in the universal serial bus supervisory unit in advance;

(2) Configure a specific address in the trusted computing module drive unit in advance;

(3) Pre-set the startup mode in the user host as USB, insert the device into the user host's universal serial bus interface and power on, the device is read by the user host, through the universal serial bus supervisory unit and flash memory read-write unit , The program stored in the flash memory read-write unit is read by the processor of the user host;

(4) The device driver stored in the flash memory read-write unit is executed;

(5) The user host disk driver program stored in the flash memory read-write unit is executed, so that the original boot program on the user host disk is read into the user host memory, and the device driver program in step (4) is passed through the universal Serial bus supervision unit, trusted computing module drive unit and trusted computing module perform integrity measurement that meets trusted standards;

(6) The device feeds back the measurement result to the user host. If it passes the measurement, it continues to execute the original boot program of the user host to realize the trusted measurement function; if it does not pass, it alarms and stops the user host startup process.
The method for introducing an external hardware root of trust for trust measurement according to claim 6, wherein the specific address in step (1) is used by the universal serial bus supervisory unit to intercept the specific universal serial bus request via The trusted computing module drive unit transforms into a trusted computing module request.
The method for introducing an external hardware root of trust for trust measurement according to claim 6, wherein the specific address in step (2) is used to determine whether the specified address is writable in combination with the state of the trusted computing module. To implement the core root trust measurement module in the flash memory read-write unit; the specific address is consistent with the addresses of the "driver of this device", "host disk driver" and "trusted measurement program" in the flash memory read-write unit.
A method for introducing an external hardware root of trust for trust measurement according to claim 6, characterized in that, in step (4), the device driver is used to provide the host user with a call interface for the startup root and the trusted root .