Skip to content

Latest commit

 

History

History
269 lines (206 loc) · 15.3 KB

sec-design.md

File metadata and controls

269 lines (206 loc) · 15.3 KB

Okay, let's create a design document for the terminal.gui project.

BUSINESS POSTURE

Business Priorities and Goals:

  • Provide a robust and user-friendly cross-platform .NET library for building terminal-based user interfaces (TUIs).
  • Enable developers to create modern-looking, interactive console applications with ease.
  • Offer a comprehensive set of UI controls and features, similar to those found in graphical user interface (GUI) frameworks.
  • Support a wide range of terminals and operating systems.
  • Maintain a high level of code quality, test coverage, and documentation.
  • Foster an active open-source community around the project.

Most Important Business Risks:

  • Inability to attract and retain developers due to usability issues, lack of features, or poor performance.
  • Security vulnerabilities that could be exploited in applications built using the library.
  • Compatibility issues with different terminals or operating systems, leading to a fragmented user experience.
  • Lack of adoption due to competition from other TUI or GUI frameworks.
  • Project abandonment or lack of maintenance, leading to outdated code and unresolved issues.

SECURITY POSTURE

Existing Security Controls:

  • security control: Code Reviews: The project uses GitHub's pull request system, which inherently includes code reviews before merging changes. (Described in GitHub repository's contribution guidelines).
  • security control: Static Analysis: The project likely uses .NET's built-in static analysis tools (e.g., Roslyn analyzers) to identify potential code quality and security issues. (Implicit in .NET development).
  • security control: Test Coverage: The project has a suite of unit tests to ensure code correctness and prevent regressions. (Visible in the GitHub repository's test directory).

Accepted Risks:

  • accepted risk: The library itself does not handle sensitive data directly, but applications built using it might. The responsibility for securing sensitive data lies with the application developer.
  • accepted risk: The library does not perform any network communication directly. Any network-related security concerns are the responsibility of the application developer.
  • accepted risk: The library relies on the underlying terminal emulator for rendering and input handling. Any security vulnerabilities in the terminal emulator are outside the scope of this project.

Recommended Security Controls:

  • security control: Input Validation: Implement robust input validation within the library's controls to prevent injection attacks or unexpected behavior.
  • security control: Fuzz Testing: Introduce fuzz testing to identify potential vulnerabilities related to unexpected or malformed input.
  • security control: Dependency Management: Regularly review and update dependencies to address known vulnerabilities. Use tools like Dependabot.
  • security control: Security Audits: Conduct periodic security audits to identify and address potential vulnerabilities.

Security Requirements:

  • Authentication: Not directly applicable to the library itself. Applications built using the library may need to implement authentication mechanisms.
  • Authorization: Not directly applicable to the library itself. Applications built using the library may need to implement authorization mechanisms.
  • Input Validation:
    • All user input received by the library's controls must be validated to ensure it conforms to expected formats and constraints.
    • Validation should prevent common attack vectors such as buffer overflows, injection attacks, and unexpected control characters.
    • Validation rules should be configurable by the application developer to accommodate different use cases.
  • Cryptography: Not directly applicable to the library itself, unless features like secure storage of settings are added. If so, use established .NET cryptography libraries.

DESIGN

C4 CONTEXT

graph LR
    User["User"] -- "Uses" --> TerminalGui["Terminal.Gui Application"]
    TerminalGui -- "Uses" --> SystemConsole["System.Console (.NET)"]
    TerminalGui -- "Uses" --> Terminal["Terminal Emulator\n(e.g., Windows Terminal, iTerm2, xterm)"]
Loading

Element Descriptions:

  • Element:

    • Name: User
    • Type: Person
    • Description: A person interacting with a Terminal.Gui application.
    • Responsibilities: Provides input to the application, views the application's output.
    • Security controls: None (handled by the application and terminal emulator).

  • Element:

    • Name: Terminal.Gui Application
    • Type: Software System
    • Description: An application built using the Terminal.Gui library.
    • Responsibilities: Provides the application's functionality, manages the user interface, handles user input.
    • Security controls: Input validation, application-specific security logic.

  • Element:

    • Name: System.Console (.NET)
    • Type: Software System
    • Description: The .NET System.Console class, providing access to the console.
    • Responsibilities: Provides low-level console input/output functionality.
    • Security controls: Relies on the underlying operating system and terminal emulator.

  • Element:

    • Name: Terminal Emulator
    • Type: Software System
    • Description: The terminal emulator used to run the application (e.g., Windows Terminal, iTerm2, xterm).
    • Responsibilities: Renders the application's output, handles user input, provides terminal-specific features.
    • Security controls: Terminal emulator's built-in security features.

C4 CONTAINER

graph LR
    User["User"] -- "Uses" --> TerminalGuiApp["Terminal.Gui Application"]
    TerminalGuiApp -- "Uses" --> TerminalGuiLib["Terminal.Gui Library"]
    TerminalGuiLib -- "Uses" --> SystemConsole["System.Console (.NET)"]
    TerminalGuiLib -- "Uses" --> Terminal["Terminal Emulator"]
Loading

Element Descriptions:

  • Element:

    • Name: User
    • Type: Person
    • Description: A person interacting with a Terminal.Gui application.
    • Responsibilities: Provides input to the application, views the application's output.
    • Security controls: None (handled by the application and terminal emulator).

  • Element:

    • Name: Terminal.Gui Application
    • Type: Container: Application
    • Description: An application built using the Terminal.Gui library.
    • Responsibilities: Provides the application's functionality, manages the user interface, handles user input.
    • Security controls: Input validation, application-specific security logic.

  • Element:

    • Name: Terminal.Gui Library
    • Type: Container: Library
    • Description: The Terminal.Gui library itself.
    • Responsibilities: Provides UI controls, layout management, event handling, input processing.
    • Security controls: Input validation within controls, safe handling of events.

  • Element:

    • Name: System.Console (.NET)
    • Type: Container: Library
    • Description: The .NET System.Console class.
    • Responsibilities: Provides low-level console input/output functionality.
    • Security controls: Relies on the underlying operating system and terminal emulator.

  • Element:

    • Name: Terminal Emulator
    • Type: Container: Application
    • Description: The terminal emulator used to run the application.
    • Responsibilities: Renders the application's output, handles user input.
    • Security controls: Terminal emulator's built-in security features.

DEPLOYMENT

Possible Deployment Solutions:

  1. Self-Contained .NET Application: The application and the .NET runtime are bundled together into a single executable. This is the most portable option.
  2. Framework-Dependent .NET Application: The application relies on a pre-installed .NET runtime on the target system. This results in a smaller application size but requires the correct runtime to be installed.
  3. NuGet Package: The Terminal.Gui library is distributed as a NuGet package, which is then included in other .NET applications.

Chosen Solution (for Terminal.Gui library itself): NuGet Package. Applications using it can choose either self-contained or framework-dependent deployment.

Deployment Diagram (for an application using Terminal.Gui, assuming self-contained deployment):

graph LR
    DevMachine["Developer Machine"] -- "Builds & Publishes" --> AppPackage["Application Package\n(Self-Contained)"]
    AppPackage -- "Deploys to" --> UserMachine["User Machine"]
    UserMachine -- "Runs in" --> Terminal["Terminal Emulator"]
Loading

Element Descriptions:

  • Element:

    • Name: Developer Machine
    • Type: Node: Device
    • Description: The machine used by the developer to build and package the application.
    • Responsibilities: Compiles the code, builds the application package.
    • Security controls: Developer machine security best practices.

  • Element:

    • Name: Application Package (Self-Contained)
    • Type: Node: Artifact
    • Description: The self-contained application package, including the .NET runtime and all dependencies.
    • Responsibilities: Contains all necessary files to run the application.
    • Security controls: Code signing, integrity checks.

  • Element:

    • Name: User Machine
    • Type: Node: Device
    • Description: The machine where the application is deployed and run.
    • Responsibilities: Executes the application.
    • Security controls: Operating system security, user account controls.

  • Element:

    • Name: Terminal Emulator
    • Type: Node: Software
    • Description: The terminal emulator used to run the application.
    • Responsibilities: Renders the application's output, handles user input.
    • Security controls: Terminal emulator's built-in security features.

BUILD

The Terminal.Gui project uses GitHub Actions for its build and CI/CD process.

Build Process Diagram:

graph LR
    Developer["Developer"] -- "Pushes code" --> GitHubRepo["GitHub Repository"]
    GitHubRepo -- "Triggers" --> GitHubActions["GitHub Actions"]
    GitHubActions -- "Runs build script" --> BuildServer["Build Server (VM)"]
    BuildServer -- "Compiles code,\nRuns tests,\nRuns linters,\nRuns SAST" --> BuildArtifacts["Build Artifacts\n(NuGet Package)"]
    BuildArtifacts -- "Published to" --> NuGet["NuGet.org"]
Loading

Build Process Description:

  1. Developer pushes code: A developer pushes code changes to the Terminal.Gui GitHub repository.
  2. GitHub Actions triggers: The push triggers a GitHub Actions workflow.
  3. Build server spins up: GitHub Actions provisions a virtual machine (build server).
  4. Build script runs: The build script (defined in the workflow) is executed on the build server. This script typically performs the following steps:
    • Compiles code: Compiles the Terminal.Gui source code using the .NET SDK.
    • Runs tests: Executes the unit test suite to ensure code correctness.
    • Runs linters: Analyzes the code for style and potential issues using linters (e.g., StyleCop).
    • Runs SAST: Performs static application security testing (SAST) to identify potential vulnerabilities. (This is a recommended addition, not currently confirmed to be present).
  5. Build artifacts created: If all steps are successful, build artifacts are created. In this case, the primary artifact is a NuGet package.
  6. Artifacts published: The NuGet package is published to NuGet.org, making it available for developers to use.

Security Controls in Build Process:

  • security control: Automated Build: The build process is fully automated using GitHub Actions, reducing the risk of manual errors and ensuring consistency.
  • security control: Version Control: All code changes are tracked in the Git repository, providing a clear audit trail.
  • security control: Code Reviews: Pull requests require code reviews before merging, ensuring that multiple developers have reviewed the changes.
  • security control: Testing: Automated unit tests are run as part of the build process, helping to prevent regressions and identify bugs early.
  • security control: Linting: Linters are used to enforce code style and identify potential issues.
  • security control: SAST (Recommended): Static application security testing should be integrated into the build process to identify potential vulnerabilities.
  • security control: Dependency Management (Recommended): Tools like Dependabot should be used to automatically identify and update outdated dependencies with known vulnerabilities.

RISK ASSESSMENT

Critical Business Processes:

  • Software development and maintenance of the Terminal.Gui library.
  • Distribution of the library via NuGet.org.
  • Community engagement and support.

Data to Protect and Sensitivity:

  • Source Code: The source code of the Terminal.Gui library itself is publicly available on GitHub. While not sensitive in the traditional sense, its integrity is crucial. Unauthorized modifications could introduce vulnerabilities or break functionality. Sensitivity: Medium (due to integrity concerns).
  • User Data (Indirect): The library itself does not handle user data directly. However, applications built using the library may handle sensitive user data. The responsibility for protecting this data lies with the application developers. Sensitivity: Variable (depends on the application).
  • Build Artifacts (NuGet Package): The integrity of the published NuGet package is critical. A compromised package could be used to distribute malicious code to developers. Sensitivity: High.
  • API Keys/Secrets (for CI/CD): Any API keys or secrets used in the GitHub Actions workflows (e.g., for publishing to NuGet.org) must be protected. Sensitivity: High.

QUESTIONS & ASSUMPTIONS

Questions:

  • Are there any specific compliance requirements (e.g., accessibility standards) that the library needs to meet?
  • What are the specific terminal emulators and operating systems that are officially supported?
  • What is the expected level of user input sanitization to be performed by applications using the library?
  • Are there plans to add features that would require handling sensitive data directly within the library (e.g., secure storage of settings)?
  • What is the process for handling security vulnerability reports?
  • Is there a dedicated security contact for the project?
  • What SAST tools are currently used, or are planned to be used, in the CI pipeline?
  • What is the current strategy for managing dependencies and addressing known vulnerabilities in those dependencies?

Assumptions:

  • BUSINESS POSTURE: The project prioritizes ease of use, cross-platform compatibility, and community engagement.
  • BUSINESS POSTURE: The project has a moderate risk appetite, typical of an open-source project.
  • SECURITY POSTURE: The project follows basic secure coding practices, but there is room for improvement in terms of proactive security measures.
  • SECURITY POSTURE: The .NET framework and underlying operating system provide a baseline level of security.
  • DESIGN: The library's design is modular and extensible, allowing for future enhancements and features.
  • DESIGN: Developers using the library are responsible for securing their own applications and handling sensitive data appropriately.
  • DESIGN: The build process is automated and reliable, using GitHub Actions.
  • DESIGN: The primary distribution method for the library is via NuGet.org.