fix(noema): validate stable OIDC exchange envelope

.github/workflows/noema-review.yml

@@ -210,6 +210,9 @@ jobs:
           if [ -z "${ACTIONS_ID_TOKEN_REQUEST_TOKEN:-}" ] || [ -z "${ACTIONS_ID_TOKEN_REQUEST_URL:-}" ]; then
             fail_unavailable "Noema app token exchange unavailable: OIDC request environment is missing."
           fi
+          if [ -z "${GITHUB_WORKFLOW_REF:-}" ]; then
+            fail_unavailable "Noema app token exchange unavailable: workflow identity is missing."
+          fi
 
           request_url="${ACTIONS_ID_TOKEN_REQUEST_URL}"
           separator="&"
@@ -242,11 +245,28 @@ jobs:
             fail_unavailable "Noema app token exchange unavailable: app token request did not complete."
           fi
 
-          app_token="$(jq -r '.token // empty' <<<"$token_response")"
+          if ! jq -e \
+            --arg target_repository "$TARGET_REPOSITORY" \
+            --arg workflow_ref "$GITHUB_WORKFLOW_REF" '
+            .ok == true
+            and (.data | type == "object")
+            and (.data.token | type == "string" and length > 0)
+            and .data.repository == $target_repository
+            and .data.workflow_ref == $workflow_ref
+            and (.data.token_expires_at | type == "string" and length > 0)
+            and (
+              (try (.data.token_expires_at | fromdateiso8601) catch null) as $expires_at
+              | ($expires_at | type == "number") and $expires_at > now
+            )
+            and (.trace_id | type == "string" and length > 0)
+          ' >/dev/null <<<"$token_response"; then
+            fail_unavailable "Noema app token exchange unavailable: response envelope was invalid."
+          fi
+
+          app_token="$(jq -r '.data.token' <<<"$token_response")"
           if [ -z "$app_token" ]; then
             fail_unavailable "Noema app token exchange unavailable: app token response was empty."
           fi
-
           echo "::add-mask::$app_token"
           echo "token=$app_token" >>"$GITHUB_OUTPUT"
 

CHANGELOG.md

@@ -55,6 +55,11 @@ Semantic Versioning where the repository publishes a release.
 
 ### Fixed
 
+- Consume Noema's stable OIDC exchange `data.token` envelope instead of the
+  nonexistent top-level `token`, and fail closed unless the response is bound
+  to the requested repository, exact executing workflow ref, non-expired token
+  timestamp, and trace identifier before masking and exporting the credential.
+
 - Publish only the sanitized cumulative Strix report tree, avoiding a later
   copy of relative scanner output that could reintroduce known internal warning
   text into uploaded security evidence.

docs/doctoring/noema-oidc-exchange-envelope.md

@@ -0,0 +1,99 @@
+# Noema OIDC exchange response-envelope contract
+
+검토 기준일: **2026-08-24**
+
+## 문제
+
+중앙 `noema-review.yml`의 OIDC credential 경로는 Noema `/exchange` 성공 응답에서 top-level `.token`을 읽고 있었습니다. 그러나 Noema의 공개 API 안정성 계약은 성공 값을 다음과 같이 `data` object 아래에 둡니다.
+
+```json
+{
+  "ok": true,
+  "data": {
+    "token": "ghs_...",
+    "repository": "ContextualWisdomLab/example",
+    "workflow_ref": "ContextualWisdomLab/.github/.github/workflows/noema-review.yml@refs/heads/main",
+    "token_expires_at": "2026-08-07T12:00:00Z"
+  },
+  "trace_id": "..."
+}
+```
+
+따라서 provider가 token을 정상 발급해도 consumer가 `.token`을 조회하면 빈 값이 되어 중앙 reviewer가 항상 실패했습니다. 이 결함은 credential이 없는 것처럼 보이지만 실제 원인은 provider/consumer schema 불일치입니다.
+
+## 결정
+
+OIDC consumer는 token field 하나만 permissive하게 조회하지 않고 다음 전체 contract를 fail closed로 검증합니다.
+
+1. top-level `ok`가 정확히 `true`여야 합니다.
+2. `data`가 JSON object여야 합니다.
+3. `data.token`이 비어 있지 않은 string이어야 합니다.
+4. `data.repository`가 요청한 `TARGET_REPOSITORY`와 정확히 같아야 합니다.
+5. Actions가 제공한 `GITHUB_WORKFLOW_REF`가 존재하고,
+   `data.workflow_ref`가 그 실행 workflow ref와 정확히 같아야 합니다.
+6. `data.token_expires_at`가 RFC 3339 UTC timestamp로 해석 가능하고 현재
+   시각보다 뒤여야 합니다.
+7. top-level `trace_id`가 비어 있지 않은 string이어야 합니다.
+8. 검증된 뒤에만 `data.token`을 추출하고 즉시 GitHub Actions mask를 적용합니다.
+9. malformed response를 진단할 때 raw response나 token 값을 출력하지 않습니다.
+
+이 변경은 Noema의 reviewer App, PAT fallback, LLM provider,
+`NVIDIA_NIM_API_KEY`, repository permission 또는 merge authority를 변경하지
+않습니다. OIDC path가 이미 발행된 stable response envelope를 정확히 소비하도록
+고치는 interoperability repair입니다. Noema producer는 원래 OIDC assertion의
+audience, repository, workflow ref 및 source SHA를 검증하고 제한된 GitHub App
+installation token을 발행합니다. 중앙 consumer는 그 assertion을 다시 검증한다고
+주장하지 않고, producer가 반환한 repository, workflow ref, expiry 및 trace binding을
+검증합니다.
+
+## 표준 근거
+
+RFC 8259는 JSON object를 name/value member의 집합으로 정의하고, member name이 고유할 때 구현 간 mapping agreement가 가능하다고 설명합니다. 또한 networked JSON text는 UTF-8을 사용해야 하며 parser가 size·depth·string length 제한을 둘 수 있음을 명시합니다. 이 변경은 shell의 loose field lookup 대신 object shape와 typed member를 명시적으로 검사하여 producer/consumer가 같은 mapping을 사용하도록 합니다.
+
+NIST SP 800-218 SSDF Version 1.1은 소프트웨어 생산자가 vulnerability의 근본 원인을 줄이고 소비자·구매자와 공통 보안 언어로 소통할 수 있도록 secure-development practices를 SDLC에 통합할 것을 권고합니다. 현재 finalized baseline은 v1.1이며, Rev. 1 / SSDF Version 1.2는 2025년 12월 공개된 initial public draft입니다. 이 변경은 실제 integration failure를 회귀 계약으로 고정하고 permissive fallback 대신 명시적 failure evidence를 남긴다는 점에서 해당 원칙을 적용합니다.
+
+RFC 6749 places an OAuth access token at the top-level `access_token` member
+(Hardt, 2012). Noema's public exchange instead wraps the GitHub App token under
+`data.token` with repository, workflow, expiry, and trace evidence. NIST SP
+800-63C-4 requires relying parties to validate assertion audience and time
+windows and to preserve replay resistance (Temoshok et al., 2025). The Noema
+producer performs the assertion validation; this consumer accepts the returned
+credential only when its stable envelope is bound to this exact repository and
+executing workflow and remains unexpired. Reading `.token` as if the response
+were RFC 6749 instead treats a schema mismatch as a missing secret and discards
+the binding evidence.
+
+## 회귀 계약
+
+- workflow가 `.token // empty`를 사용하지 않습니다.
+- `jq -e`가 stable envelope, target repository, exact executing workflow ref,
+  future expiry 및 trace identifier를 검증합니다.
+- 추출 경로는 `.data.token`입니다.
+- malformed envelope는 `response envelope was invalid`로 실패합니다.
+- raw response는 diagnostic output으로 반사하지 않습니다.
+- token은 output 기록 전에 `::add-mask::` 처리됩니다.
+
+## 롤백과 호환성
+
+롤백은 top-level `.token`으로 되돌리는 것이 아니라, provider의 실제 stable envelope가 변경되었다는 독립적으로 검증된 근거가 있을 때 producer와 consumer 계약을 같은 변경에서 함께 갱신하는 방식으로 수행합니다. 기존 GitHub App 및 PAT credential 경로는 이 OIDC schema repair와 독립적으로 유지되며, standalone product repositories는 중앙 reviewer의 내부 response parsing에 런타임 결합되지 않습니다.
+
+## References (APA 7th)
+
+Bray, T. (2017). *The JavaScript Object Notation (JSON) data interchange format* (RFC 8259). Internet Engineering Task Force. https://doi.org/10.17487/RFC8259
+
+ContextualWisdomLab. (2026). *Noema API specification* [Computer software
+documentation]. GitHub.
+https://github.com/ContextualWisdomLab/noema/blob/main/docs/api-spec.md
+
+Hardt, D. (Ed.). (2012). *The OAuth 2.0 authorization framework* (RFC 6749).
+Internet Engineering Task Force. https://doi.org/10.17487/RFC6749
+
+Souppaya, M., Scarfone, K., & Dodson, D. (2022). *Secure Software Development Framework (SSDF) version 1.1: Recommendations for mitigating the risk of software vulnerabilities* (NIST Special Publication 800-218). National Institute of Standards and Technology. https://doi.org/10.6028/NIST.SP.800-218
+
+National Institute of Standards and Technology. (2025, December 17). *Secure Software Development Framework (SSDF) version 1.2 is available for public comment*. https://www.nist.gov/news-events/news/2025/12/secure-software-development-framework-ssdf-version-12-available-public
+
+Temoshok, D., Richer, J., Choong, Y.-Y., Fenton, J., Lefkovitz, N.,
+Regenscheid, A., & Galluzzo, R. (2025). *Digital identity guidelines:
+Federation and assertions* (NIST Special Publication 800-63C-4). National
+Institute of Standards and Technology.
+https://doi.org/10.6028/NIST.SP.800-63c-4

tests/test_noema_oidc_exchange_contract.py

@@ -0,0 +1,171 @@
+"""Regression contracts for the Noema OIDC exchange consumer."""
+
+import json
+import os
+import subprocess
+from datetime import UTC, datetime, timedelta
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+WORKFLOW_PATH = REPO_ROOT / ".github" / "workflows" / "noema-review.yml"
+
+
+def workflow_step(workflow: str, name: str) -> str:
+    """Return one named workflow step without parsing untrusted YAML tags."""
+    marker = f"      - name: {name}\n"
+    start = workflow.index(marker)
+    try:
+        end = workflow.index("\n      - name:", start + len(marker))
+    except ValueError:
+        end = len(workflow)
+    return workflow[start:end]
+
+
+def workflow_run_script(workflow: str, name: str) -> str:
+    """Return the executable shell body from one named workflow step."""
+    step = workflow_step(workflow, name)
+    marker = "        run: |\n"
+    body = step.split(marker, maxsplit=1)[1]
+    return "\n".join(line.removeprefix("          ") for line in body.splitlines())
+
+
+def run_exchange_script(
+    tmp_path: Path, token_response: dict[str, object]
+) -> subprocess.CompletedProcess[str]:
+    """Execute the production exchange shell with a deterministic fake transport."""
+    workflow = WORKFLOW_PATH.read_text(encoding="utf-8")
+    script = workflow_run_script(workflow, "Exchange Noema app token through OIDC")
+    fake_bin = tmp_path / "bin"
+    fake_bin.mkdir(exist_ok=True)
+    fake_curl = fake_bin / "curl"
+    fake_curl.write_text(
+        """#!/usr/bin/env python3
+import os
+import sys
+
+if "audience=" in sys.argv[-1]:
+    print('{"value":"synthetic-oidc-assertion"}')
+else:
+    print(os.environ["FAKE_TOKEN_RESPONSE"])
+""",
+        encoding="utf-8",
+    )
+    fake_curl.chmod(0o755)
+    github_output = tmp_path / "github-output"
+    github_output.unlink(missing_ok=True)
+    environment = os.environ.copy()
+    environment.update(
+        {
+            "PATH": f"{fake_bin}{os.pathsep}{environment['PATH']}",
+            "ACTIONS_ID_TOKEN_REQUEST_TOKEN": "synthetic-request-token",
+            "ACTIONS_ID_TOKEN_REQUEST_URL": "https://actions.invalid/id-token",
+            "OIDC_AUDIENCE": "synthetic-noema-review",
+            "TOKEN_EXCHANGE_URL": "https://noema.invalid/exchange",
+            "TARGET_REPOSITORY": "ExampleOrg/example-repository",
+            "GITHUB_WORKFLOW_REF": (
+                "ExampleOrg/control-plane/.github/workflows/"
+                "noema-review.yml@refs/heads/main"
+            ),
+            "GITHUB_OUTPUT": str(github_output),
+            "FAKE_TOKEN_RESPONSE": json.dumps(token_response),
+        }
+    )
+    return subprocess.run(
+        ["bash", "-c", script],
+        check=False,
+        capture_output=True,
+        env=environment,
+        text=True,
+    )
+
+
+def test_oidc_exchange_consumes_noema_standard_success_envelope() -> None:
+    """Require the central reviewer to consume Noema's stable data envelope."""
+    workflow = WORKFLOW_PATH.read_text(encoding="utf-8")
+    exchange = workflow_step(workflow, "Exchange Noema app token through OIDC")
+
+    assert ".token // empty" not in exchange
+    assert "Noema app token exchange unavailable: response envelope was invalid." in exchange
+    assert 'if [ -z "${GITHUB_WORKFLOW_REF:-}" ]; then' in exchange
+    assert '--arg target_repository "$TARGET_REPOSITORY"' in exchange
+    assert '--arg workflow_ref "$GITHUB_WORKFLOW_REF"' in exchange
+    assert ".ok == true" in exchange
+    assert "(.data | type == \"object\")" in exchange
+    assert "(.data.token | type == \"string\" and length > 0)" in exchange
+    assert ".data.repository == $target_repository" in exchange
+    assert ".data.workflow_ref == $workflow_ref" in exchange
+    assert "(.data.token_expires_at | type == \"string\" and length > 0)" in exchange
+    assert "fromdateiso8601" in exchange
+    assert "$expires_at > now" in exchange
+    assert "(.trace_id | type == \"string\" and length > 0)" in exchange
+    assert 'app_token="$(jq -r \'.data.token\' <<<"$token_response")"' in exchange
+
+
+def test_oidc_exchange_keeps_token_out_of_diagnostics() -> None:
+    """Require envelope failures to avoid reflecting raw credential material."""
+    workflow = WORKFLOW_PATH.read_text(encoding="utf-8")
+    exchange = workflow_step(workflow, "Exchange Noema app token through OIDC")
+
+    assert 'echo "$token_response"' not in exchange
+    assert 'printf "%s" "$token_response"' not in exchange
+    mask = 'echo "::add-mask::$app_token"'
+    output = 'echo "token=$app_token" >>"$GITHUB_OUTPUT"'
+    assert mask in exchange
+    assert output in exchange
+    assert exchange.index(mask) < exchange.index(output)
+
+
+def test_oidc_exchange_accepts_only_exact_live_producer_binding(tmp_path: Path) -> None:
+    """Exercise the production shell against realistic valid and invalid envelopes."""
+    repository = "ExampleOrg/example-repository"
+    workflow_ref = (
+        "ExampleOrg/control-plane/.github/workflows/"
+        "noema-review.yml@refs/heads/main"
+    )
+    future_expiry = (datetime.now(UTC) + timedelta(hours=1)).strftime(
+        "%Y-%m-%dT%H:%M:%SZ"
+    )
+    valid = {
+        "ok": True,
+        "data": {
+            "token": "synthetic-app-token",
+            "repository": repository,
+            "workflow_ref": workflow_ref,
+            "token_expires_at": future_expiry,
+        },
+        "trace_id": "synthetic-trace-id",
+    }
+
+    accepted = run_exchange_script(tmp_path, valid)
+
+    assert accepted.returncode == 0, accepted.stdout + accepted.stderr
+    assert "::add-mask::synthetic-app-token" in accepted.stdout
+    assert (tmp_path / "github-output").read_text(encoding="utf-8") == (
+        "token=synthetic-app-token\n"
+    )
+
+    invalid_responses = [
+        {"ok": True, "token": "synthetic-app-token"},
+        {**valid, "data": {**valid["data"], "repository": "ExampleOrg/other"}},
+        {
+            **valid,
+            "data": {**valid["data"], "workflow_ref": "ExampleOrg/other/workflow"},
+        },
+        {
+            **valid,
+            "data": {
+                **valid["data"],
+                "token_expires_at": "2000-01-01T00:00:00Z",
+            },
+        },
+        {**valid, "data": {**valid["data"], "token_expires_at": "not-a-time"}},
+        {key: value for key, value in valid.items() if key != "trace_id"},
+    ]
+
+    for invalid in invalid_responses:
+        rejected = run_exchange_script(tmp_path, invalid)
+        diagnostic = rejected.stdout + rejected.stderr
+        assert rejected.returncode != 0
+        assert "response envelope was invalid" in diagnostic
+        assert "synthetic-app-token" not in diagnostic
+        assert not (tmp_path / "github-output").exists()