CN103927490A - OS secure startup method and device - Google Patents

Abstract

Embodiments of the present invention provide a method and device for safely starting an operating system. The method for safely starting the operating system of the present invention includes: performing signature authentication on UEFI BIOS, and if the authentication is passed, performing signature authentication on the operating system boot program; using a secure hash algorithm to measure the operating system boot program after the authentication is passed, and the The measured results are taken as the root of trust; the root of trust is used as the initial value, and multiple operating system configuration files are measured in turn; the final measured result is compared with the expected security value, and the operating system is verified to be safe to start. The embodiment of the present invention realizes the security check of the operating system boot program through the method of digital signature authentication, measures the safe operating system boot program to generate a root of trust, measures the operating system OS step by step according to the root of trust, and passes the chain of trust to the BIOS Extending to the OS, it solves the problem that in the prior art, the safety of the startup program after the BootLoader cannot be guaranteed.

Description

Operating system security startup method and device

technical field

The embodiments of the present invention relate to the field of computer technology, and in particular, to a method and device for safely starting an operating system.

Background technique

In today's information age, protecting information security and providing a reliable computing environment has become an inevitable requirement of informatization. With the rapid evolution of malware, malware is taking the Basic Input Output System (BIOS) as the preferred attack target, and it is difficult to defend against viruses that attack the underlying firmware and startup programs. Credibility and security are particularly important.

The BIOS is solidified in a Read-Only Memory (ROM) chip on the computer motherboard, which stores the most important basic input and output programs, power-on self-test programs, system self-start programs, and menu programs of the computer. Its main function is to provide the computer with the lowest and most direct hardware settings, control and access. Secure boot is a firmware verification method defined by the Unified Extensible Firmware Interface (UEFI) standard specification, which describes how platform firmware manages security certificates, firmware verification, and the interface between firmware and operating system. The purpose is to prevent the intrusion of malicious software. Secure boot uses data signature and key authentication methods. When the motherboard leaves the factory, some reliable public keys can be built in. Any operating system or hardware driver that wants to be loaded on this motherboard must pass the authentication of these keys, that is, these software must use the corresponding The private key is signed, otherwise the board refuses to load.

The booting process of the entire operating system can be roughly divided into BIOS booting, BootLoader booting, and operating system booting. Boot Loader is a small program that runs before the operation of the operating system kernel. It is located in the Master Boot Record (MBR for short), that is, the operating system boot program. Task. Secure boot can only guarantee the trustworthiness of BIOS and BootLoader programs during the boot process, but cannot guarantee the security of boot programs after BootLoader.

Contents of the invention

Embodiments of the present invention provide a method and device for safely starting an operating system, so as to overcome the inability to guarantee the safety of a startup program after BootLoader in the prior art.

In a first aspect, an embodiment of the present invention provides a method for safely starting an operating system, including:

Signature authentication is performed on the UEFI BIOS of the unified extensible firmware interface basic input and output system, and if the authentication is passed, the signature authentication is performed on the operating system boot program;

Using a secure hash algorithm to measure the boot program of the operating system after passing the authentication, and use the obtained measurement result as a root of trust;

Using the root of trust as an initial value, measure multiple operating system configuration files in sequence;

The final measurement result obtained is compared with the expected security value to verify whether the operating system is safely started.

With reference to the first aspect, in a first possible implementation manner of the first aspect, taking the root of trust as an initial value and sequentially measuring multiple operating system configuration files includes:

Using a secure hash algorithm to measure the operating system configuration file, measure the measurement result and the initial value as the input value of the secure hash algorithm again, use the obtained value as the measurement result, and use the measurement result Measure the next operating system profile as the new initial value until all operating system profiles are measured.

In combination with the first aspect and the first possible implementation of the first aspect, in the second possible implementation of the first aspect, the obtained final measurement result is compared with the expected security value to verify whether it is safe to start The operating system includes:

If the final measurement result is consistent with the expected security value, the operating system is safely started; if not, the operating system is not started.

In combination with the second possible implementation of the first aspect, the third possible implementation of the first aspect further includes:

Perform the measurement of the secure hash algorithm on the trusted platform module TPM;

The measurement result is stored in a platform configuration register PCR in the TPM.

In a second aspect, an embodiment of the present invention provides an operating system secure boot device, including:

The signature authentication module is used to perform signature authentication on the unified extensible firmware interface basic input and output system UEFIBIOS. If the authentication is passed, the signature authentication is performed on the operating system boot program;

A measurement module, configured to use a secure hash algorithm to measure the boot program of the operating system after passing the authentication, and use the obtained measurement result as a root of trust;

The measurement module is further configured to use the root of trust as an initial value to sequentially measure multiple operating system configuration files;

The verification module is configured to obtain the final measurement result and compare it with the expected security value, and verify whether the operating system is safely started.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the measurement module is specifically configured to:

Using a secure hash algorithm to measure the operating system configuration file, measure the measurement result and the initial value as the input value of the secure hash algorithm again, use the obtained value as the measurement result, and use the measurement result Measure the next operating system profile as the new initial value until all operating system profiles are measured.

In combination with the second aspect and the first possible implementation of the second aspect, in the second possible implementation of the second aspect, the verification module is specifically used to:

If the final measurement result is consistent with the expected security value, the operating system is safely started; if not, the operating system is not started.

With reference to the second possible implementation of the second aspect, in a third possible implementation of the second aspect, the measurement module includes a trusted platform module (TPM), configured to perform a secure hash algorithm on the TPM measure of

The device further includes: a platform configuration register PCR, configured to store the measurement result.

The method and device for safely starting the operating system in the embodiment of the present invention, by performing signature authentication on UEFI BIOS, if the authentication is passed, the operating system boot program is signed and authenticated; the operating system boot program after the authentication is passed using a secure hash algorithm Perform measurement, and use the obtained measurement result as the root of trust; use the root of trust as the initial value, measure multiple operating system configuration files in turn; obtain the final measurement result and compare it with the expected security value, and verify whether it is safe to start The operating system realizes the security verification of the operating system boot program through digital signature authentication, the operating system boot program for measuring security generates a root of trust, and the operating system OS is measured step by step according to the root of trust, and the chain of trust is divided into The BIOS is extended to the OS, which solves the problem that in the prior art, the safety of the startup program after the BootLoader, that is, the OS startup program cannot be guaranteed.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a flow chart of Embodiment 1 of the safe startup method of the operating system of the present invention;

FIG. 1A is a schematic diagram of the execution process of Embodiment 1 of the method for safely starting an operating system according to the present invention;

FIG. 2 is a schematic structural diagram of Embodiment 1 of an operating system security startup device of the present invention;

FIG. 3 is a schematic structural diagram of Embodiment 1 of an operating system secure boot device according to the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

FIG. 1 is a flow chart of Embodiment 1 of a method for securely starting an operating system according to the present invention. FIG. 1A is a schematic diagram of the execution process of Embodiment 1 of the method for safely starting an operating system according to the present invention. The execution subject of this embodiment is the device for securely starting the operating system, and the device may be implemented by software and/or hardware. As shown in Figure 1, the method of this embodiment may include:

Step 101, performing signature authentication on the unified extensible firmware interface basic input and output system UEFI BIOS, and if the authentication is passed, performing signature authentication on the boot program of the operating system.

Specifically, as shown in FIG. 1A, when the operating system is started, the UEFI BIOS is first authenticated by signature, and after the authentication is passed, the operating system boot program in the disk is read for signature authentication. Signature authentication can use CA digital signature authentication. The secure boot method is used to ensure the security of the BIOS, the signature authentication process is transparent, and the user acceptance is high.

The multi-operating system bootloader (GRand Unified Bootloader, GRUB for short) is an operating system bootloader. Used to guide different systems, such as windows, linux, etc. GRUB is the implementation of the multi-boot specification, which allows users to have multiple operating systems in the computer at the same time, and choose the operating system they want to run when the computer starts. GRUB can be used to select different kernels on an operating system partition, and can also be used to pass boot parameters to those kernels.

During the UEFI BIOS signature authentication, the Option Rom signature can be authenticated at the same time. The hardware board will be compatible with third-party network cards and peripherals such as Redundant Array of Independent Disks (Redundant Array of Independent Disks, referred to as RAID) cards, and the manufacturers of external cards will provide traditional The Option Rom binary file or the Extensible Firmware Interface (Extensible Firmware Interface referred to as EFI) driver is given to the operating system UEFI BIOS. During the startup process of the operating system, the UEFI BIOS will complete the initialization of the external card by calling the Option Rom code.

Step 102: Use a secure hash algorithm to measure the boot program of the operating system after the authentication has passed, and use the obtained measurement result as a root of trust.

Specifically, the idea of Secure Hash Algorithm (SHA for short) is to receive a piece of plaintext, and then convert it into a piece of (usually smaller) ciphertext in an irreversible way, which can also be simply understood as taking a The process of converting a string of input codes (called pre-mapping or information) and converting them into a short-length, fixed-digit output sequence that is a hash value (also known as a message digest or message authentication code).

Use the secure hash algorithm to measure the boot program of the operating system after passing the authentication, and obtain the information summary, which is the measurement result, as the root of trust, and further measure the operating system kernel file.

Step 103, using the root of trust as an initial value, sequentially measure multiple operating system configuration files.

Optionally, using the root of trust as an initial value, multiple operating system profiles are sequentially measured, including:

Use the secure hash algorithm to measure the operating system configuration file, use the measurement result and the initial value as the input value of the secure hash algorithm to measure again, use the obtained value as the measurement result, and use the measurement result as the new initial value pair The next operating system profile is measured until all operating system profiles are measured.

Specifically, as shown in Figure 1A, the operating system configuration files include virtual machine monitor Xen, operating system kernel files such as linux Kernel, root file system Initrd, module Module, key system files, etc., and multiple operating system configuration files are measured The following method can be used: use the root of trust as the initial value N0, measure the first operating system configuration file using a secure hash algorithm, and use the measurement result VALUE and the initial value N0 as the input value of the secure hash algorithm to measure again. Use the obtained value as the measurement result N1 and store the measurement result, that is, the formula N1=SHA(N0+VALUE) can be used, and the measurement result can be used as a new initial value to measure the next operating system configuration file, that is, N0 =N1, carry out the above process until the measurement of all operating system configuration files is completed, and save the measurement results of the measurement of all operating system configuration files.

Step 104: Obtaining the final measurement result and comparing it with the expected security value to verify whether the operating system is safely started.

Optionally, compare the obtained final measurement result with the expected security value, and verify whether the operating system is safely started, including:

If the final measurement result is consistent with the expected security value, the operating system will be safely started; if not, the operating system will not be started.

Specifically, the final measurement result stored in the acquisition step 103 is compared with the preset expected security value, and if they are consistent, the operating system will be safely started; if not, the operating system will not be started.

Optionally, the method of this embodiment may also include:

Perform the measurement of the secure hash algorithm on the trusted platform module TPM;

The measurement results are stored in the platform configuration register PCR in the TPM.

Specifically, a Trusted Computing Module (Trusted Platform Module, referred to as TPM) 2.0 can be used to measure the secure hash algorithm. The TPM2.0 chip complies with the TPM standard specification defined by the Trusted Computing Group (Trusted Computing Group, referred to as TCG). The measurement results in the measurement process may be stored in platform configuration registers (Platform Configuration Registers, PCR for short) in the TPM.

In this embodiment, by performing signature authentication on the basic input and output system BIOS, if the authentication is passed, the operating system boot program is signed and authenticated; using a secure hash algorithm to measure the operating system boot program after the authentication is passed, will be obtained The obtained measurement result is used as the root of trust; the root of trust is used as the initial value, and multiple operating system configuration files are measured in turn; the final measurement result is compared with the expected security value, and it is verified whether the operating system is safely started. The method of verifying the safety of the operating system boot program through digital signature authentication is realized, and the safe operating system boot program is measured to generate a root of trust. According to the root of trust, the operating system OS is measured step by step, and the chain of trust is extended from BIOS to OS. The solution is that in the prior art, the security of the startup program after the BootLoader, that is, the OS startup program cannot be guaranteed.

FIG. 2 is a schematic structural diagram of Embodiment 1 of the device for securely starting an operating system in the present invention. As shown in FIG. , the signature authentication module 201 is used to carry out signature authentication to the unified Extensible Firmware Interface Basic Input and Output System UEFI BIOS, and if the authentication is passed, the signature authentication is performed to the operating system boot program; the measurement module 202 is used to use the secure hash algorithm Measure the boot program of the operating system after passing the authentication, and use the obtained measurement result as a root of trust; the measurement module 202 is also used to use the root of trust as an initial value, and measure multiple operating system configuration files in sequence ; The verification module 203 is used to obtain the final measurement result and compare it with the expected security value to verify whether the operating system is safely started.

Optionally, the measurement module 202 is specifically used for:

Using a secure hash algorithm to measure the operating system configuration file, measure the measurement result and the initial value as the input value of the secure hash algorithm again, use the obtained value as the measurement result, and use the measurement result Measure the next operating system profile as the new initial value until all operating system profiles are measured.

Optionally, the verification module 203 is specifically used for:

If the final measurement result is consistent with the expected security value, the operating system is safely started; if not, the operating system is not started.

Optionally, the measurement module 202 may include a trusted platform module TPM2020, which is used to measure the secure hash algorithm on the TPM;

The device 20 for safely booting the operating system may further include: a platform configuration register PCR204 for storing the measurement result.

The device of this embodiment can be used to implement the technical solution of the method embodiment shown in FIG. 1 , and its implementation principle and technical effect are similar, and will not be repeated here.

FIG. 3 is a schematic structural diagram of Embodiment 1 of an operating system secure boot device according to the present invention. As shown in FIG. 3 , the operating system secure boot device 30 provided in this embodiment includes a processor 301 and a memory 302 . The operating system security boot device 30 may further include a transmitter 303 and a receiver 304 . The transmitter 303 and the receiver 304 may be connected to the processor 301 . In terms of hardware implementation, the transmitter, receiver, and processor can be enclosed in one chip, or implemented with one chip respectively. Wherein, the transmitter 303 is used to send data or information, the receiver 304 is used to receive data or information, the memory 302 stores execution instructions, and when the operating system security boot device 30 is running, the processor 301 communicates with the memory 302, and the processor 301 invokes the execution instruction in the memory 302 to execute the technical solution described in the first method embodiment. The implementation principle and technical effect are similar, and will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units or modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or modules can be Incorporation may either be integrated into another system, or some features may be omitted, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or modules may be in electrical, mechanical or other forms.

The modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or may also be distributed to multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Those of ordinary skill in the art can understand that all or part of the steps for implementing the above method embodiments can be completed by program instructions and related hardware. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above-mentioned method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (8)

1. A method for safely starting an operating system, comprising: Signature authentication is performed on the UEFI BIOS of the unified extensible firmware interface basic input and output system, and if the authentication is passed, the signature authentication is performed on the operating system boot program; Using a secure hash algorithm to measure the boot program of the operating system after passing the authentication, and use the obtained measurement result as a root of trust; Using the root of trust as an initial value, measure multiple operating system configuration files in sequence; The final measurement result obtained is compared with the expected security value to verify whether the operating system is safely started. 2. The method according to claim 1, wherein the step of using the root of trust as an initial value to successively measure multiple operating system configuration files comprises: Using a secure hash algorithm to measure the operating system configuration file, measure the measurement result and the initial value as the input value of the secure hash algorithm again, use the obtained value as the measurement result, and use the measurement result Measure the next operating system profile as the new initial value until all operating system profiles are measured. 3. The method according to claim 1 or 2, wherein said obtaining the final measurement result is compared with an expected security value, and verifying whether the operating system is safely started includes: If the final measurement result is consistent with the expected security value, the operating system is safely started; if not, the operating system is not started. 4. The method according to claim 3, further comprising: Perform the measurement of the secure hash algorithm on the trusted platform module TPM; The measurement result is stored in a platform configuration register PCR in the TPM. 5. An operating system security boot device, characterized in that, comprising: The signature authentication module is used to perform signature authentication on the unified extensible firmware interface basic input and output system UEFIBIOS. If the authentication is passed, the signature authentication is performed on the operating system boot program; A measurement module, configured to use a secure hash algorithm to measure the boot program of the operating system after passing the authentication, and use the obtained measurement result as a root of trust; The measurement module is further configured to use the root of trust as an initial value to sequentially measure multiple operating system configuration files; The verification module is configured to obtain the final measurement result and compare it with the expected security value, and verify whether the operating system is safely started. 6. The device according to claim 5, wherein the measuring module is specifically used for: Using a secure hash algorithm to measure the operating system configuration file, measure the measurement result and the initial value as the input value of the secure hash algorithm again, use the obtained value as the measurement result, and use the measurement result Measure the next operating system profile as the new initial value until all operating system profiles are measured. 7. The device according to claim 5 or 6, wherein the verification module is specifically used for: If the final measurement result is consistent with the expected security value, the operating system is safely started; if not, the operating system is not started. 8. The device according to claim 7, wherein the measurement module comprises a trusted platform module (TPM), configured to perform measurement of a secure hash algorithm on the TPM; The device further includes: a platform configuration register PCR, configured to store the measurement result.