Section 54: Language Security Model¶

TECHSPEC-54 — Section 54 · Version 0.1 · Status: Initial Draft

Status: draft. This section is an Initial Draft (Section 57 is a Working Register). It describes intended or proposed behavior, not a finalized, implemented language rule. Do not treat examples here as normative.

1. Purpose¶

This section consolidates the language's security model. It does not replace the detailed requirements in the trust, permissions, authentication, cryptography, process, and sandboxing sections.

The objective is to make security assumptions explicit and prevent language features from silently bypassing them.

2. Security Principles¶

The language follows these principles: - Least privilege. - Explicit trust boundaries. - Secure defaults. - No implicit authority escalation. - Explicit handling of untrusted input. - Defense in depth. - Auditable security-sensitive operations. - Honest reporting of security evidence and limitations.

3. Threat Model¶

A program may encounter: - Malicious or malformed input. - Compromised dependencies. - Untrusted plugins or modules. - Unauthorized callers. - Malicious network peers. - Resource exhaustion. - Configuration errors. - Runtime or operating-system vulnerabilities. - Incorrect application logic.

The language cannot eliminate every threat. Each application must identify its assets, trust boundaries, attackers, and deployment assumptions.

4. Security-Relevant Types and Effects¶

Security-sensitive values should use dedicated types where useful, including: - Untrusted input. - Validated values. - Secrets and cryptographic keys. - Authenticated identities. - Authorized capabilities. - File and network handles.

Effects and permissions must identify security-sensitive operations.

5. Secure Defaults¶

The language should default to: - No undeclared external access. - No implicit shell execution. - No implicit type conversion that loses information. - No silent failure handling. - No public visibility unless specified by the applicable declaration rules. - No untrusted code execution during compilation. - No automatic permission inheritance.

6. Dependency Security¶

Dependencies must have locked identities and versions, integrity metadata, provenance information where available, and declared permissions.

A valid signature can establish who signed an artifact or that it has not changed since signing. It does not prove that the artifact is safe or correct.

7. Secret Handling¶

Secrets must be distinguishable from ordinary strings where practical.

The language and standard library should prevent accidental logging, serialization, or exposure through diagnostics. Redaction is a safeguard, not a proof that no secret can leak.

8. Security Diagnostics¶

Security diagnostics must identify the violated rule, affected source location, relevant trust boundary, and available evidence.

The compiler must distinguish confirmed vulnerabilities from warnings, suspicious patterns, and unknown conditions.

9. Security Verification¶

Security claims must identify their scope and evidence: - Static analysis. - Runtime enforcement. - Tests. - Independent review. - Formal proof of a bounded property. - External platform or service guarantees.

No single category establishes complete application security.

10. Design Goal¶

The language should make unsafe authority and trust transitions difficult to express accidentally, while reporting clearly what remains outside its guarantees.

Source and related sections¶

Source file: TECHSPEC-54.md (preserved in source-original/LANG/). See the specification index, the glossary, and the cross-reference index.