Itsg Assessment

ITSG-33 / CCCS Medium Compliance Assessment

Map a project's architecture and codebase to Canadian ITSG-33 security controls (CCCS Medium Cloud Profile). Produces a phased assessment with AWS shared responsibility inheritance, gap analysis, and risk-rated remediation guidance.

Important Rules

These rules govern all phases. Read before starting any assessment work.

• Evidence over assumption: Every "Implemented" status must cite a file path or pattern. If no evidence, mark "Not Implemented" or ask.
• Don't inflate compliance: When uncertain, mark "Partially Implemented" with notes.
• Respect inheritance: Many controls are AWS-inherited or GC Org-level. Don't mark these as gaps.
• Protected B data classification: Flag any handling of Protected B data without explicit encryption, access control, and residency controls.
• GC data residency: Data residency defaults to ca-central-1. Flag resources deployed outside Canadian AWS regions (ca-central-1, ca-west-1).
• CCCS guidance: Apply CCCS Medium Cloud Profile control selection as defined in ITSP.50.103 Annex B. Follow CCCS guidance when interpreting control applicability.
• No fabricated controls: Only map controls from ITSG-33. Verify against official sources when uncertain.
• Phase checkpoints are mandatory: Always pause between phases for user input.
• Smart re-run is default: If previous outputs exist, offer smart re-run first.

Output

All output goes to docs/compliance/. Create the directory if it doesn't exist.

Before writing any phase output, read references/phase-templates.md for the required format.

Example

User: "Run an ITSG-33 compliance assessment on this CDK project."

1. Phase 0 — Validate controls against official ITSG-33 sources
2. Phase 1 — Scan cdk.json, lib/, pipeline definitions; identify AWS services, data residency, trust boundaries; write docs/compliance/phase1-discovery.md; checkpoint with user
3. Phase 2 — Map each control from references/itsg33-controls.md against discovered architecture; classify inheritance; write docs/compliance/phase2-control-mapping.md; checkpoint with user
4. Phase 3 — Produce risk-rated gap entries for unimplemented controls; write docs/compliance/phase3-gap-analysis.md and docs/compliance/assessment-summary.md

Smart Re-run

Before starting any phase, check if previous phase outputs exist. If they do:

1. Read the existing output and compare against current project state (file modification times, git diff)
2. If changes detected (any IaC file modified since the phase output was written, or any new AWS service added to the codebase), re-run that phase
3. If no changes, report "Phase N output is current — skipping"
4. Always ask: "Previous assessment found. Re-run from scratch or smart re-run?"

Phase 0 — Framework Validation

Runs first, before any assessment work. Validates control data against official sources.

1. Look up the ITSG-33 Annex 3A URL in references/official-references.md, then fetch that page to verify control families and IDs
2. Compare against the control tables in references/itsg33-controls.md
3. If differences found: update references/itsg33-controls.md and report changes
4. If no differences: report "Phase 0 complete — all controls match official sources"

If the fetch fails (network error, page unavailable, timeout): skip validation, report "Phase 0 skipped — using cached controls from references/itsg33-controls.md", and proceed to Phase 1. Do not block the assessment.

Phase 1 — Architecture Discovery

1.1 — Detect Tech Stack

Detect the IaC framework in use — this determines search terms in Phase 1.2:

Also note language runtime and CI/CD platform for context, but do not let them drive control mapping.

1.2 — Analyze Codebase

Search for security-relevant patterns across these categories: IAM / Access Control, Encryption, Logging / Auditing, Network, Data Protection, Backup / Recovery.

Adapt search terms to the detected IaC framework (CDK constructs, Terraform resource types, or CloudFormation resource names).

If no IaC or security-relevant patterns are found, report what was searched and ask the user whether security controls exist outside the codebase.

1.3 — Read Architecture Docs

Search for docs/ARCHITECTURE.md, docs/DESIGN.md, README.md, cdk.json, pipeline definitions.

1.4 — Produce Output

Write docs/compliance/phase1-discovery.md. Before writing, read references/phase-templates.md for the Phase 1 template format.

1.5 — User Checkpoint

Present the Phase 1 summary and ask:

• "Does this accurately represent your architecture?"
• "Any out-of-band security controls not visible in code (SCPs, SSO, manual configs)?"

Wait for confirmation before Phase 2.

Phase 2 — Control Mapping

Read the control families and inheritance model from references/itsg33-controls.md. For every control, determine:

1. Status: Implemented / Partially Implemented / Not Implemented / Not Applicable
2. Inheritance: Classify using the inheritance model in references/itsg33-controls.md (AWS Inherited / AWS Shared / Customer Implemented / GC Org-level)
3. Evidence: Specific file paths, line numbers, resource configurations
4. Notes: Caveats, assumptions, dependencies

Write docs/compliance/phase2-control-mapping.md. Before writing, read references/phase-templates.md for the Phase 2 template format.

User Checkpoint

Present posture breakdown and uncertain controls. Ask: "Any controls where you have additional context?" Wait for confirmation before Phase 3.

Phase 3 — Gap Analysis

For every control marked Not Implemented or Partially Implemented, produce a risk-rated remediation entry. Before writing, read references/phase-templates.md for the gap entry format and risk rating criteria.

Write:

• docs/compliance/phase3-gap-analysis.md — ordered by risk rating, then effort
• docs/compliance/assessment-summary.md — executive summary

Present the executive summary and top recommended actions.

Error Handling

References

• Control family tables and inheritance model: references/itsg33-controls.md — read during Phase 2 to map each control
• Output format templates: references/phase-templates.md — read before writing any phase output
• Official documentation links: references/official-references.md — read during Phase 0 for validation URLs