RU2581552C2 - Method of trusted download in virtualised media - Google Patents

Abstract

FIELD: information technologies.

SUBSTANCE: method includes creation of a section on a hard disc of virtualised medium with a loader providing for trusted download of virtual machines, addition of the module of trusted download microsoftware into a virtual BIOS, realisation of virtual machine start, realisation of loader configuration. Then the virtual machine is restarted, the virtual machine user is authenticated, the control of virtual machine files integrity is performed. The virtual machine is started in accordance with the virtual machine download scenario.

EFFECT: increased protection of virtualised media against unauthorised access due to provision of trusted download of virtual machines in virtualised media.

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Description

The invention relates to methods for providing access to the resources of a virtualized environment (virtualization environment), and more particularly to methods for trusted loading of virtual machines. The method is intended to protect the virtualization environment from unauthorized loading of virtual machines and from gaining the possibility of unauthorized access to confidential information stored inside virtual machines.

Information systems built on the basis of virtualization technologies, which have been rapidly developed since the beginning of the 21st century, have serious advantages over information systems built without their use. Their use reduces the number of physical servers (and at the same time brings significant economic benefits), improves the quality of administration and the availability of information system infrastructure, and many other benefits.

On the other hand, along with the advantages of virtualization, there are also disadvantages, among which it is necessary to highlight the growing number of threats to the information security of virtual infrastructure. One of the threats aimed at violating the confidentiality of information stored in a virtualized environment is the threat associated with obtaining unauthorized access to virtual machines and user data inside them. An effective measure to combat this threat is the trusted loading of virtual machines, i.e. loading of virtual machines after successful authentication procedures for the user of the virtual machine and monitoring the integrity of the files of the virtual machine.

The prior art method for providing a secure boot computer system, which consists in downloading a secure boot code; loading a secure operating system for authentication, while the secure operating system uses drivers from the main operating system; user authentication in a secure operating system up to providing access to the main operating system;

after authentication, the encryption key is released, the main operating system is rebooted and decrypted using the encryption key (US 7,360,073 B1, 04/15/2008, G06F 1/26).

Also known from the prior art are hardware modules of trusted loading of operating systems that perform the following functions:

- identification and authentication of users prior to loading the OS using personal electronic identifiers;

- blocking unauthorized loading of OS from external removable media;

- integrity control of system objects, user objects and MDZ software before loading the OS;

- registration of actions of both users and programs;

- providing opportunities for external applications (working with a random number sensor, working with electronic identifiers, etc.). (E. Nikitin, V. Shramko. Is it always locked? How to secure a computer with a trusted boot module. Http://samag.ru/archive/article/1068).

The disadvantage of the above method and modules trusted boot is their inability to provide trusted boot virtual machines in virtualized environments. In addition, the presence of a hardware board has its drawbacks associated with the ability to bypass the transfer of control to it by both physical and firmware methods.

The technical result to which this invention is directed is to ensure trusted loading of virtual machines in virtualized environments, which in turn increases the security of virtualized environments from unauthorized access.

The technical result is achieved through the use of trusted boot in virtualized environments, which consists in the fact that:

create a partition on the hard drive of a virtualized environment with a bootloader that provides trusted boot virtual machines;

add the trusted boot firmware module to the virtual BIOS of the virtualized environment;

start a virtual machine for which trusted download is required, while the trusted boot firmware module searches the hard drive for a virtualized bootloader environment that provides trusted loading of virtual machines and transfers control to it;

configure the bootloader to ensure trusted loading of virtual machines by adding a virtual machine boot script, creating user profiles for which virtual machine boot is allowed, and selecting virtual machine files whose integrity must be controlled;

restart a virtual machine that requires trusted boot;

authenticate the user of the virtual machine;

control the integrity of the virtual machine files subject to successful authentication of the user of the virtual machine;

load the virtual machine in accordance with the virtual machine boot scenario and provided that the integrity control of the files of the virtual machine is successfully passed.

The figure 1 presents a typical diagram of a virtualized environment with a type I hypervisor, i.e. installed directly on hardware.

Figure 2 shows the boot process of a virtual machine without using the trusted boot method.

Figure 3 shows the trusted boot process of a virtual machine in a virtualized environment.

In a virtualized environment, the following components are usually assumed (Figure 1):

- hypervisor;

- Hardware;

- virtual machine;

- guest operating system (not shown, is the contents of the virtual machine).

The hypervisor creates an environment for the functioning of other programs by simulating the hardware of computer technology, managing these tools and guest operating systems operating in this environment. Type I hypervisor is installed directly on the hardware as system software.

A virtual machine consists of virtual devices for processing, storing and transmitting data and may additionally contain software and user data. The guest operating system is installed on a virtual machine.

In general, booting a virtual machine in a virtualized environment involves the following steps (figure 2):

1. Launch the boot sector of the virtual BIOS, which performs integrity control of the remaining system BIOS components.

2. Next, the virtual BIOS initializes and performs a health check of the virtual hardware simulated by the hypervisor, such as the motherboard, chipset, memory, and processor.

3. The virtual BIOS calls additional system software that extends the capabilities of the primary virtual BIOS or initializes additional virtual hardware, such as a video card, network card, etc.

4. After all the necessary virtual hardware has been configured, the virtual BIOS searches for the device (hard disk, USB disk, optical drive), from which further loading of the virtual machine is possible, and then transfers control to the loader on this device.

5. The bootloader initializes and loads the kernel of the guest operating system installed on the virtual machine. After completing these processes, boot control is transferred from the virtual BIOS to the operating system.

The above sequence of actions for loading a virtual machine has the disadvantage that an unauthorized user can get access to the boot settings of the virtual machine and the data inside the virtual machine, which can lead to a violation of the confidentiality of information stored in the virtual machine and spoofing of the virtual boot script files machines (integrity threat). To eliminate the above drawback, you must use trusted boot virtual machines.

The proposed trusted boot method in virtualized environments allows trusted boot of virtual machines.

The trusted boot firmware module is integrated directly into the virtual BIOS and starts its work at the very early stages of starting virtual machines. Its main function is to detect, authenticate the bootloader that provides trusted loading of virtual machines, and transfer control to it.

A bootloader that provides trusted boot for virtual machines is a module that provides basic functions for trusted boot inside virtual machines.

After the first start of the virtual machine, for which it is necessary to provide trusted boot, it is necessary to configure the bootloader, which provides trusted boot and located on the hard disk of a virtualized environment. The purpose of configuring the bootloader to ensure trusted loading of virtual machines is to create configuration files used by the bootloader to provide trusted loading of virtual machines to change the following aspects of the bootloader:

- management of integrity control of files of virtual machines (creation, deletion of groups of targets (files) for integrity monitoring);

- management of virtual machines (creating, deleting, creating, editing boot scripts, assigning / reconciling target groups for integrity monitoring);

- user management (creating, deleting, setting passwords, privileges, assigning virtual machines available for launch).

In order to increase the reliability and protection against unauthorized changes, the created configuration files in the process of their generation can be signed with a private key during configuration. Private keys can be stored on an external medium, for example, on a flash drive.

After configuring the bootloader that provides trusted loading of virtual machines, the virtual machine for which it is necessary to ensure trusted loading is restarted in order for the changes made at the configuration stage to take effect.

At the next restart of the virtual machine, the user goes through the authentication procedure. For example, it could be password authentication. In this case, the correct user password is set at the bootloader configuration stage, which ensures trusted loading of virtual machines. If the password entered during user authentication was correct, then the bootloader, which provides trusted loading of virtual machines, proceeds to the next step - monitoring the integrity of the virtual machine files. In case of failure, the virtual machine starts up (the virtual machine stops) and the system returns to its original state. Thus, authentication allows you to limit the circle of people who have access to the virtual machine data to the list of authorized users defined at the bootloader configuration stage.

At the next stage, the bootloader, which provides trusted loading of virtual machines, checks (controls) the integrity of the files of virtual machines, a list of which was created at the bootloader configuration stage. Integrity control is carried out using checksum algorithms (for example, MD5, SHA-2 or GOST R 34.11-2012). Integrity control allows an authorized user to make sure that no unauthorized changes were made to its files before the virtual machine started. If the integrity check is positive, the virtual machine starts loading: the kernel of the guest OS located inside the virtual machine is loaded into memory and control is transferred to it or control is transferred to the next bootloader. In case of failure, the virtual machine starts up (the virtual machine stops) and the system returns to its original state.

The bootloader, which provides trusted loading of virtual machines, can, after the user authentication procedure, provide a choice of virtual machines to start from the list of virtual machines allowed to run for this user, created at the bootloader configuration stage.

Additionally, a bootloader that provides trusted boot of virtual machines can use the public key to authenticate configuration files if these files are generated and signed with the private key during configuration.

Claims (1)

A trusted boot method in virtualized environments is that:
create a partition on the hard drive of a virtualized environment with a bootloader that provides trusted boot virtual machines;
add the trusted boot firmware module to the virtual BIOS of the virtualized environment;
start a virtual machine for which trusted download is required, while the trusted boot firmware module searches the hard drive for a virtualized bootloader environment that provides trusted loading of virtual machines and transfers control to it;
configure the bootloader to ensure trusted loading of virtual machines by adding a virtual machine boot script, creating user profiles for which virtual machine boot is allowed, and selecting virtual machine files whose integrity must be controlled;
restart a virtual machine that requires trusted boot;
authenticate the user of the virtual machine;
control the integrity of the virtual machine files subject to successful authentication of the virtual machine user;
load the virtual machine in accordance with the virtual machine boot scenario, provided that the integrity control of the files of the virtual machine is successfully passed.

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