Implementing mandatory integrity control in Astra Linux OS for access control of user data

Implementing mandatory integrity control in Astra Linux OS for access control of user data

Devyanin P.N. (RusBITech-Astra, Moscow, Russia)
Gorbatov V.V. (RusBITech-Astra, Moscow, Russia)
Trubnikov A.A. (RusBITech-Astra, Moscow, Russia)

Abstract

Mandatory Integrity Control (MIC) in the Astra Linux OS, as in many other OS such as the Microsoft Windows family or IBM AIX, is traditionally applied to protect high-integrity (trusted) system software from unauthorized modification or takeover of control by low-integrity (untrusted) user adversaries. For access control to user data, the Discretionary Access Control (DAC) standard for Linux family OS is typically used. However, it does not establish clear rules for access control, which often leads to administrative errors and complicates the scientific justification of security. A more flexible and advanced Role-Based Access Control (RBAC) could potentially solve this problem, but it has not yet been fully implemented in the Astra Linux OS. The Multilevel security (MLS) originally employed in this OS under consideration enables the assignment of non-hierarchical confidentiality categories to user accounts, subjects (processes), and objects (files, directories), reflecting either the content of the data or their affiliation with structural units of the organization where the Astra Linux OS is used. However, MLS rules impose stringent restrictions on access control that are excessive in scenarios where preventing the leakage of confidential data is not a priority. In this context, the paper proposes considering the application of MIC for protecting user data, as it also utilizes non-hierarchical categories. By associating integrity levels with trust, MIC aligns with organizational hierarchies or multi-domain networks. It enforces the no-write-up rule, preventing subjects from modifying higher-integrity objects, and optionally, via the SSI flag, the no-read-up rule, restricting reads from higher-integrity objects. As an example of practical validation of the proposed approach, the paper examines technologies for employing MIC to control access to user data in the Samba and NFS network file systems. Overall, this approach does not require significant modifications to MIC in the Astra Linux OS, and for the scientific justification of its security, the MROSL DP-model has already been developed.

Keywords

operating system; mandatory integrity control; MROSL DP-model; Astra Linux.

Edition

Proceedings of the Institute for System Programming, vol. 38, issue 3, part 1, 2026, pp. 71-86

ISSN 2220-6426 (Online), ISSN 2079-8156 (Print).

DOI: 10.15514/ISPRAS-2026-38(3)-4

For citation

Devyanin P.N. Gorbatov V.V., Trubnikov A.A. Implementing mandatory integrity control in Astra Linux OS for access control of user data. Proceedings of the Institute for System Programming, vol. 38, issue 3, part 1, 2026, pp. 71-86 DOI: 10.15514/ISPRAS-2026-38(3)-4.

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