mimic-big/tasks/spec-decisions.md

Spec decisions log

This file tracks implementation arbitrations on top of the frozen spec (Projects/Mimic — Spec.md in the RT-SecondBrain vault).

Format: one entry per decision, newest first.

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2026-05-21 — Team kickoff decisions

D-001 — SOC collaboration hypothesis

Context. Devils-advocate flagged the sociological assumption that SOC analysts will cote in the live cockpit. Decision. Hypothesis accepted as-is. No paper PoC. Risk owned by lead RT.

D-002 — Mimic deployment location

Context. Spec §6 NF-network did not pin where Mimic is physically deployed. Decision. Mimic runs on RT infrastructure. SOC client connects through the existing RT reverse proxy (Caddy, out of Mimic scope). Mimic → Mythic / Home C2 through outbound VPN. RT R&D (TTP library, stealthy variants) never sits on client premises.

D-003 — Authentication strategy

Context. Spec mentions OIDC Keycloak but lab onboarding cost is high. Decision. v1 ships local auth (username/password, bcrypt, Flask server-side sessions). v2 adds Keycloak OIDC. The RBAC model is group-based from day one, so OIDC will map claims to existing groups without touching application code. SOC sessions remain a distinct mechanism (soc_session.token_opaque bcrypt hash, clear token out-of-band).

D-004 — C2 credential storage (T2)

Context. Engagement.config_json (encrypted JSON column) vs dedicated table. Decision. Dedicated table c2_credential (id, engagement_id, c2_type, config_json_fernet, version, created_at, retired_at). Active row per engagement = retired_at IS NULL, highest version. Rotation = insert + retire previous. Fernet key in env, never in DB.

D-005 — Cleanup template variable sources (T3)

Context. Jinja {{outputs.X}} source ambiguity. Decision. Two accessors:

• {{outputs.text}} → run_step.output_text (stdout/UTF-8 text).
• {{outputs.blob("<key>")}} → reads from output_blob_ref, hard cap 10 MB (consistent with F8 evidence limit), UTF-8 decoding with latin-1 fallback, silent refusal + log entry if the blob is non-decodable. regex_extract always operates on the resulting string.

D-006 — SOC session token storage (T4)

Context. soc_session.token_opaque storage form. Decision. bcrypt hash. Clear token generated server-side at session creation, returned once in the API response, delivered out-of-band to the SOC analyst. Never re-displayable.

D-007 — Reverse proxy scope

Context. Mimic exposure to internet for SOC client access. Decision. Reverse proxy (Caddy + TLS + IP allowlist) handled by existing RT infrastructure. Mimic ships an HTTP listener on localhost only; the deployment playbook wires it behind the existing proxy.

D-008 — Group-based RBAC vs spec F11 fixed roles

Context. Spec F11 declares 3 fixed roles (rt_operator, rt_lead, soc_analyst) with an explicit permission matrix. Sprint 0 plan (B0.6, D-003) introduces group / permission / group_permission / user_group tables to prepare OIDC v2 claim-to-group mapping without code change. Decision. Group-based model accepted as an implementation layout, not a scope extension:

• The 3 spec roles MUST exist as the 3 seeded groups at bootstrap (rt_operator, rt_lead, soc_analyst).
• The F11 permission matrix is the canonical source: groups receive exactly the permissions of their matching role; no custom permissions UI v1.
• Custom groups, group editing UI, or per-engagement group overrides = OUT of v1.
• Any drift between seeded group permissions and the F11 matrix is a spec violation, not a configuration choice.

D-009 — ttp_version table forbidden (H32 reaffirmed)

Context. Sprint 0 plan (B0.2) lists ttp_version among the initial tables. Spec hypothesis H32 explicitly excludes this: "Snapshot de rejouabilité = run.snapshot_json uniquement (pas de table ttp_version séparée — simplification MVP)". Decision. Drop ttp_version from the initial migration. The ttp.version column (informational, §8) is kept. Replayability lives solely on run.snapshot_json. Re-introducing ttp_version requires explicit spec amendment through the team-lead.