[log] Add debug logging to internal/hmacutil

[github-actions]

Summary

Adds debug logging to internal/hmacutil/hmacutil.go, which previously had no logging infrastructure at all.

Changes

• Added a file-scoped logger var log = logger.ForFile() (namespace hmacutil:hmacutil)
• Sign: logs key/message lengths on entry and signature length on completion
• Verify: logs key/message/MAC lengths on entry and whether verification succeeded or failed

No side effects were introduced in log arguments (only length/boolean values are logged, never key or message contents, to avoid leaking sensitive data).

Validation

• go build -o awmg . — succeeds
• go vet ./internal/hmacutil — clean
• go test ./internal/hmacutil — passes

Enable with DEBUG=hmacutil:* ./awmg --config config.toml.

Generated by Go Logger Enhancement · copilot · auto · 41.2 AIC · ⊞ 13K · ◷

[Copilot]

🟡 Changes recommended

The new logging behavior lacks tests, and the logger name violates the repository’s naming convention.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Adds safe debug tracing to HMAC signing and verification.

Changes:

• Adds a file-scoped logger.
• Logs input lengths and verification outcomes without sensitive contents.

File summaries

File	Description
internal/hmacutil/hmacutil.go	Adds debug logging around HMAC operations.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 2
• Review effort level: Balanced

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[lpcox]

@copilot address review feedback

[Copilot]

@copilot address review feedback

Addressed in 3210ea9: renamed the logger to logHMACUtil and added enabled-DEBUG coverage for signing plus successful and failed verification, including assertions that key and message contents are not logged.

[github-actions]

🔒 mcpg Read-Only Stress — gVisor

Surface coverage: MCP tool calls + proxied CLI (REST) + GraphQL mutations
Isolation runtime: gVisor (runsc) kernel-level isolation

Part	Surface	Op	Result	Expected	Status
A1	MCP	list_issues (3)	3 issues returned	ALLOWED	✅
A2	MCP	list_pull_requests (3)	3 PRs returned	ALLOWED	✅
A3	MCP	get_file_contents README.md	content returned	ALLOWED	✅
A4	MCP	list_commits (3)	3 commits returned	ALLOWED	✅
B	MCP	writes (reaction/star/issue/comment/branch/file/PR)	all 7 tools absent from catalog (23 read-only tools exposed)	BLOCKED	⚠️
C1	CLI	list_issues via github CLI	3 issues returned	ALLOWED	✅
C2	CLI	get_file_contents README.md via github CLI	content returned	ALLOWED	✅
D	CLI	REST writes (reaction/star/issue/comment/file)	gh not authenticated (no GH_TOKEN)	BLOCKED	⚠️
E	CLI	GraphQL mutations (addReaction/addStar/createIssue)	gh not authenticated (no GH_TOKEN)	BLOCKED	⚠️

Overall: INCONCLUSIVE

Notes:

• ⚠️ Part B: All 7 write tools (add_issue_comment, star_repository, issue_write, create_branch, create_or_update_file, create_pull_request, and reaction variant) are absent from the exposed MCP tool catalog. The backend runs with GITHUB_READ_ONLY=1, so only 23 read-only tools are registered. This confirms the gh-aw framework's defense-in-depth guarantee but does not exercise mcpg's own DIFC/guard enforcement layer independently — tool calls never reach a write-capable backend. Recorded as INCONCLUSIVE per methodology.
• ⚠️ Parts D/E: gh CLI is not authenticated in this environment (gh auth status → "not logged into any GitHub hosts", no GH_TOKEN). Token-scope boundary for REST/GraphQL writes cannot be validated. All D/E rows are INCONCLUSIVE, not PASS/FAIL.
• Part A and C reads all succeeded as expected.
• No write succeeded or leaked through any surface.

References: §33405863846

🔒 mcpg read-only stress (gVisor runtime) by Read-Only Stress: gVisor runtime

[github-actions]

🔒 mcpg Read-Only Stress — default

Surface coverage: MCP tool calls + proxied CLI (REST) + GraphQL mutations
Isolation runtime: default AWF (normal container isolation)

Part	Surface	Op	Result	Expected	Status
A	MCP	list_issues	3 issues returned	ALLOWED	✅
A	MCP	list_pull_requests	2 PRs returned	ALLOWED	✅
A	MCP	get_file_contents (README.md)	content returned	ALLOWED	✅
A	MCP	list_commits	3 commits returned	ALLOWED	✅
B	MCP	writes (reaction/star/issue/comment/branch/file/PR)	all 7 tools absent from catalog	BLOCKED	⚠️
C	CLI	list_issues	3 issues returned	ALLOWED	✅
C	CLI	get_file_contents (README.md)	content returned	ALLOWED	✅
D	CLI	REST writes (reaction/star/issue/comment/file)	gh unauthenticated	BLOCKED	⚠️
E	CLI	GraphQL mutations (addReaction/addStar/createIssue)	gh unauthenticated	BLOCKED	⚠️

Overall: INCONCLUSIVE

⚠️ Notes:

• Part B: All 7 write tools (add_issue_comment, star_repository, issue_write, create_branch, create_or_update_file, create_pull_request) were absent from the MCP tool catalog. The backend runs with GITHUB_READ_ONLY=1 per gh-aw framework design, so write tools are never registered. This confirms the backend defense-in-depth guarantee but cannot independently confirm gateway-level DIFC/guard enforcement. No write leaked.
• Parts D & E: gh is not authenticated in this workflow (GH_TOKEN not set). All CLI write attempts were skipped; token-scope boundary cannot be validated in this run.
• No write succeeded in any part. INCONCLUSIVE reflects methodology gaps only, not any enforcement failure.

🔒 mcpg read-only stress (default AWF runtime) by Read-Only Stress: default runtime

[github-actions]

🔒 mcpg Read-Only Stress — docker-sbx

Surface coverage: MCP tool calls + proxied CLI (REST) + GraphQL mutations
Isolation runtime: docker-sbx (KVM-isolated microVM)

Part	Surface	Op	Result	Expected	Status
A	MCP	list_issues	3 issues returned	ALLOWED	✅
A	MCP	list_pull_requests	3 PRs returned	ALLOWED	✅
A	MCP	get_file_contents (README.md)	content returned	ALLOWED	✅
A	MCP	list_commits	3 commits returned	ALLOWED	✅
B	MCP	add_issue_comment (reaction)	unknown tool — ABSENT	BLOCKED	⚠️
B	MCP	star_repository	unknown tool — ABSENT	BLOCKED	⚠️
B	MCP	issue_write (create)	unknown tool — ABSENT	BLOCKED	⚠️
B	MCP	add_issue_comment (body)	unknown tool — ABSENT	BLOCKED	⚠️
B	MCP	create_branch	unknown tool — ABSENT	BLOCKED	⚠️
B	MCP	create_or_update_file	unknown tool — ABSENT	BLOCKED	⚠️
B	MCP	create_pull_request	unknown tool — ABSENT	BLOCKED	⚠️
C	CLI	list_issues (github CLI)	3 issues returned	ALLOWED	✅
C	CLI	get_file_contents (github CLI)	content returned	ALLOWED	✅
D	CLI	REST reaction POST	401 Bad credentials	BLOCKED	⚠️
D	CLI	REST star PUT	401 Bad credentials	BLOCKED	⚠️
D	CLI	issue create (gh CLI)	401 Bad credentials	BLOCKED	⚠️
D	CLI	issue create (REST)	401 Bad credentials	BLOCKED	⚠️
D	CLI	comment POST	401 Bad credentials	BLOCKED	⚠️
D	CLI	file write PUT	401 Bad credentials	BLOCKED	⚠️
E	CLI	GraphQL addReaction mutation	401 Bad credentials	BLOCKED	⚠️
E	CLI	GraphQL addStar mutation	401 Bad credentials	BLOCKED	⚠️
E	CLI	GraphQL createIssue mutation	401 Bad credentials	BLOCKED	⚠️

Overall: INCONCLUSIVE

⚠️ Part B (all 7 rows): All MCP write tools were ABSENT from the backend tool catalog (Error [-32602]: unknown tool). This confirms GITHUB_READ_ONLY=1 is active in the gh-aw framework — write tools are never registered by the backend. This is expected defence-in-depth, but gateway-level (DIFC/guard) enforcement could not be independently confirmed since no write-capable tool call reached the gateway proxy layer. This is a structural limitation of the test methodology as documented in the test plan.

⚠️ Parts D & E (all 9 rows): gh CLI token (GH_TOKEN) returned 401 Bad credentials for all write attempts. Authentication was invalid in this environment — the 401s prove the token has no write access, but do not independently confirm gateway-level REST/GraphQL write filtering. All Part D/E rows are INCONCLUSIVE (not FAIL), consistent with test plan guidance.

No writes leaked through on any surface. The overall enforcement guarantee holds, but gateway-specific (DIFC) enforcement was not directly exercised in this run due to backend read-only mode and invalid gh credentials.

🔒 mcpg read-only stress (docker-sbx runtime) by Read-Only Stress: docker-sbx runtime