feat: enforce signed target maturity evidence

tools/assessments/boundary-evidence.py

@@ -0,0 +1,363 @@
+#!/usr/bin/env python3
+"""Issue and immediately verify a sanitized target-boundary proof."""
+
+from __future__ import annotations
+
+import argparse
+from copy import deepcopy
+from datetime import UTC, datetime
+import json
+from pathlib import Path
+import sys
+
+
+META_ROOT = Path(__file__).resolve().parents[2]
+for tools_root in (
+    META_ROOT / "tools" / "assessments",
+    META_ROOT / "tools" / "release",
+):
+    if str(tools_root) not in sys.path:
+        sys.path.insert(0, str(tools_root))
+
+from cryptography.hazmat.primitives import serialization  # noqa: E402
+from cryptography.hazmat.primitives.asymmetric.ed25519 import (  # noqa: E402
+    Ed25519PrivateKey,
+)
+
+from govoplan_assessment.atomic_io import (  # noqa: E402
+    AtomicJsonWriteError,
+    atomic_write_json,
+)
+from govoplan_assessment.boundary_evidence import (  # noqa: E402
+    issue_boundary_evidence,
+)
+from govoplan_assessment.capability_fit import review_capability_fit  # noqa: E402
+from govoplan_assessment.evidence import (  # noqa: E402
+    public_key_material_from_keyrings,
+    validate_payload,
+)
+
+
+MAX_INPUT_BYTES = 16 * 1024 * 1024
+MAX_OUTPUT_BYTES = 4 * 1024 * 1024
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--assessment", type=Path, required=True)
+    parser.add_argument(
+        "--assessment-schema",
+        type=Path,
+        default=META_ROOT / "docs" / "capability-fit.schema.json",
+    )
+    parser.add_argument("--catalog", type=Path, required=True)
+    parser.add_argument("--keyring", type=Path, required=True)
+    parser.add_argument("--trusted-keyring", type=Path, required=True)
+    parser.add_argument("--installed-evidence", type=Path, required=True)
+    parser.add_argument(
+        "--installed-evidence-schema",
+        type=Path,
+        default=META_ROOT / "docs" / "installed-composition-evidence.schema.json",
+    )
+    parser.add_argument("--installer-receipt", type=Path, required=True)
+    parser.add_argument(
+        "--installer-receipt-schema",
+        type=Path,
+        default=META_ROOT / "docs" / "installer-receipt.schema.json",
+    )
+    parser.add_argument("--installer-authority-keyring", type=Path, required=True)
+    parser.add_argument(
+        "--installer-authority-keyring-schema",
+        type=Path,
+        default=META_ROOT / "docs" / "installer-receipt-authority-keyring.schema.json",
+    )
+    parser.add_argument(
+        "--claims",
+        type=Path,
+        required=True,
+        help="Private target-run claim manifest; artifact paths are not published.",
+    )
+    parser.add_argument(
+        "--claims-schema",
+        type=Path,
+        default=META_ROOT / "docs" / "capability-fit-boundary-run.schema.json",
+    )
+    parser.add_argument("--authority-keyring", type=Path, required=True)
+    parser.add_argument(
+        "--authority-keyring-schema",
+        type=Path,
+        default=META_ROOT
+        / "docs"
+        / "capability-fit-proof-authority-keyring.schema.json",
+    )
+    parser.add_argument(
+        "--signing-key",
+        action="append",
+        default=[],
+        required=True,
+        metavar="KEY_ID=/PATH/PRIVATE.pem",
+        help="Repeat for independent authorities needed to cover all claim scopes.",
+    )
+    parser.add_argument("--expected-external-provider-subject")
+    parser.add_argument("--output", type=Path, required=True)
+    parser.add_argument("--review-output", type=Path, required=True)
+    parser.add_argument(
+        "--boundary-evidence-schema",
+        type=Path,
+        default=META_ROOT / "docs" / "capability-fit-boundary-evidence.schema.json",
+    )
+    args = parser.parse_args(argv)
+    if args.output.resolve() == args.review_output.resolve():
+        parser.error("proof and review output paths must differ")
+
+    assessment = read_object(args.assessment, label="assessment")
+    assessment_schema = read_object(args.assessment_schema, label="assessment schema")
+    catalog = read_object(args.catalog, label="catalog")
+    published_keyring = read_object(args.keyring, label="published keyring")
+    trusted_keyring = read_object(args.trusted_keyring, label="trusted keyring")
+    installed_evidence = read_object(
+        args.installed_evidence, label="installed evidence"
+    )
+    installed_schema = read_object(
+        args.installed_evidence_schema, label="installed evidence schema"
+    )
+    installer_receipt = read_object(args.installer_receipt, label="installer receipt")
+    installer_receipt_schema = read_object(
+        args.installer_receipt_schema, label="installer receipt schema"
+    )
+    installer_authorities = read_object(
+        args.installer_authority_keyring, label="installer authority keyring"
+    )
+    installer_authority_schema = read_object(
+        args.installer_authority_keyring_schema,
+        label="installer authority keyring schema",
+    )
+    claim_manifest = read_object(args.claims, label="target-run claim manifest")
+    claim_schema = read_object(args.claims_schema, label="target-run claim schema")
+    authority_keyring = read_object(
+        args.authority_keyring, label="proof-authority keyring"
+    )
+    authority_schema = read_object(
+        args.authority_keyring_schema, label="proof-authority keyring schema"
+    )
+    boundary_schema = read_object(
+        args.boundary_evidence_schema, label="boundary evidence schema"
+    )
+
+    _require_schema(claim_manifest, claim_schema, label="target-run claim manifest")
+    _require_schema(
+        authority_keyring, authority_schema, label="proof-authority keyring"
+    )
+    base_report = review_capability_fit(
+        assessment=assessment,
+        schema=assessment_schema,
+        catalog=catalog,
+        published_keyring=published_keyring,
+        trusted_keyring=trusted_keyring,
+        workspace_root=None,
+        installed_evidence=installed_evidence,
+        installed_evidence_schema=installed_schema,
+        installer_receipt=installer_receipt,
+        installer_receipt_schema=installer_receipt_schema,
+        installer_authority_keyring=installer_authorities,
+        installer_authority_keyring_schema=installer_authority_schema,
+        installed_evidence_mode="imported_unsigned",
+    )
+    _require_release_origin(base_report, parser=parser)
+
+    claims = resolve_claim_artifact_paths(
+        claim_manifest.get("claims"), base_dir=args.claims.resolve().parent
+    )
+    signing_keys = read_signing_keys(tuple(args.signing_key))
+    expires_at = parse_datetime(claim_manifest.get("expires_at"), label="expires_at")
+    forbidden_keys = public_key_material_from_keyrings(
+        published_keyring,
+        trusted_keyring,
+        installer_authorities,
+    )
+    try:
+        proof = issue_boundary_evidence(
+            assessment=assessment,
+            installed_evidence=installed_evidence,
+            proof_id=str(claim_manifest.get("proof_id") or ""),
+            claims=claims,
+            authority_keyring=authority_keyring,
+            signing_keys=signing_keys,
+            expires_at=expires_at,
+            expected_external_provider_subject=(
+                args.expected_external_provider_subject
+            ),
+            forbidden_authority_public_keys=forbidden_keys,
+            release_origin_verified=True,
+        )
+    except ValueError as exc:
+        parser.error(str(exc))
+    _require_schema(proof, boundary_schema, label="issued boundary evidence")
+
+    review = review_capability_fit(
+        assessment=assessment,
+        schema=assessment_schema,
+        catalog=catalog,
+        published_keyring=published_keyring,
+        trusted_keyring=trusted_keyring,
+        workspace_root=None,
+        installed_evidence=installed_evidence,
+        installed_evidence_schema=installed_schema,
+        installer_receipt=installer_receipt,
+        installer_receipt_schema=installer_receipt_schema,
+        installer_authority_keyring=installer_authorities,
+        installer_authority_keyring_schema=installer_authority_schema,
+        boundary_evidence=proof,
+        boundary_evidence_schema=boundary_schema,
+        boundary_authority_keyring=authority_keyring,
+        boundary_authority_keyring_schema=authority_schema,
+        installed_evidence_mode="imported_unsigned",
+        expected_external_provider_subject=args.expected_external_provider_subject,
+    )
+    supplied_scopes = {str(claim.get("scope")) for claim in proof["claims"]}
+    unchecked = sorted(
+        scope
+        for scope in supplied_scopes
+        if review.get("proof_scope", {}).get(scope, {}).get("checked") is not True
+    )
+    if unchecked:
+        parser.error(
+            "issued proof did not pass immediate verification for scopes: "
+            + ", ".join(unchecked)
+        )
+    write_object(args.output, proof, label="boundary evidence")
+    write_object(args.review_output, review, label="capability-fit review")
+    print(
+        json.dumps(
+            {
+                "proof_id": proof["proof_id"],
+                "scopes": sorted(supplied_scopes),
+                "reference_readiness": review.get("proof_scope", {}).get(
+                    "reference_readiness"
+                ),
+                "output": str(args.output),
+                "review_output": str(args.review_output),
+            },
+            sort_keys=True,
+        )
+    )
+    return 0
+
+
+def read_object(path: Path, *, label: str) -> dict[str, object]:
+    try:
+        if path.stat().st_size > MAX_INPUT_BYTES:
+            raise ValueError("input exceeds size limit")
+        payload = json.loads(path.read_bytes().decode("utf-8"))
+    except (OSError, UnicodeDecodeError, json.JSONDecodeError, ValueError) as exc:
+        raise SystemExit(f"Could not read {label}") from exc
+    if not isinstance(payload, dict):
+        raise SystemExit(f"{label.capitalize()} must be a JSON object")
+    return payload
+
+
+def read_signing_keys(values: tuple[str, ...]) -> dict[str, Ed25519PrivateKey]:
+    result: dict[str, Ed25519PrivateKey] = {}
+    for value in values:
+        key_id, separator, path_text = value.partition("=")
+        if not separator or not key_id or not path_text or key_id in result:
+            raise SystemExit(
+                "--signing-key must uniquely use KEY_ID=/path/to/private.pem"
+            )
+        try:
+            key = serialization.load_pem_private_key(
+                Path(path_text).expanduser().read_bytes(), password=None
+            )
+        except (OSError, ValueError) as exc:
+            raise SystemExit("Could not read boundary signing key") from exc
+        if not isinstance(key, Ed25519PrivateKey):
+            raise SystemExit("Boundary signing keys must be Ed25519")
+        result[key_id] = key
+    return result
+
+
+def resolve_claim_artifact_paths(
+    claims: object, *, base_dir: Path
+) -> list[dict[str, object]]:
+    if not isinstance(claims, list):
+        raise SystemExit("Target-run claim manifest has no claim list")
+    resolved = deepcopy(claims)
+    for claim in resolved:
+        if not isinstance(claim, dict):
+            continue
+        artifacts = claim.get("artifacts")
+        if not isinstance(artifacts, list):
+            continue
+        for artifact in artifacts:
+            if not isinstance(artifact, dict) or not isinstance(
+                artifact.get("path"), str
+            ):
+                continue
+            path = Path(artifact["path"]).expanduser()
+            artifact["path"] = path if path.is_absolute() else base_dir / path
+    return resolved
+
+
+def parse_datetime(value: object, *, label: str) -> datetime:
+    if not isinstance(value, str):
+        raise SystemExit(f"{label} must be an RFC 3339 date-time")
+    try:
+        parsed = datetime.fromisoformat(value.replace("Z", "+00:00"))
+    except ValueError as exc:
+        raise SystemExit(f"{label} must be an RFC 3339 date-time") from exc
+    if parsed.tzinfo is None:
+        raise SystemExit(f"{label} must include a timezone")
+    return parsed.astimezone(UTC)
+
+
+def _require_schema(
+    payload: dict[str, object], schema: dict[str, object], *, label: str
+) -> None:
+    errors = validate_payload(payload=payload, schema=schema)
+    if errors:
+        raise SystemExit(f"{label.capitalize()} failed schema validation: {errors[0]}")
+
+
+def _require_release_origin(
+    report: dict[str, object], *, parser: argparse.ArgumentParser
+) -> None:
+    proof_scope = report.get("proof_scope")
+    if not isinstance(proof_scope, dict):
+        parser.error("capability-fit review did not return proof scope")
+    required = (
+        "catalog_signature_and_keyring",
+        "catalog_signature_and_trusted_keyring",
+        "published_keyring_hash",
+        "release_metadata",
+        "installed_artifacts",
+        "installed_record_integrity",
+        "installed_release_origin",
+    )
+    failed = sorted(
+        scope
+        for scope in required
+        if not isinstance(proof_scope.get(scope), dict)
+        or proof_scope[scope].get("valid") is not True
+    )
+    observation = proof_scope.get("installed_evidence_observation")
+    if (
+        not isinstance(observation, dict)
+        or observation.get("receipt_authenticated") is not True
+    ):
+        failed.append("installed_evidence_observation.receipt_authenticated")
+    if failed:
+        parser.error(
+            "trusted release and installer evidence must pass before target proof issuance: "
+            + ", ".join(failed)
+        )
+
+
+def write_object(path: Path, payload: dict[str, object], *, label: str) -> None:
+    try:
+        atomic_write_json(path, payload, max_bytes=MAX_OUTPUT_BYTES)
+    except AtomicJsonWriteError as exc:
+        raise SystemExit(f"Could not securely write {label}") from exc
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

tools/assessments/capability-fit.py

@@ -20,9 +20,11 @@ for tools_root in (ASSESSMENT_TOOLS_ROOT, RELEASE_TOOLS_ROOT):
 
 from govoplan_assessment import (  # noqa: E402
     collect_installed_composition,
+    enforce_required_boundary_scopes,
     render_review,
     review_capability_fit,
 )
+from govoplan_assessment.evidence import REFERENCE_READINESS_SCOPES  # noqa: E402
 from govoplan_assessment.atomic_io import (  # noqa: E402
     AtomicJsonWriteError,
     atomic_write_json,
@@ -169,6 +171,21 @@ def parse_args(argv: list[str] | None = None) -> argparse.Namespace:
             "never supply a URL, credential, or endpoint identifier."
         ),
     )
+    parser.add_argument(
+        "--require-reference-readiness",
+        action="store_true",
+        help="Fail unless every reference-readiness boundary scope is current and positive.",
+    )
+    parser.add_argument(
+        "--require-external-provider-proof",
+        action="store_true",
+        help="Fail unless current positive external-provider evidence is present.",
+    )
+    parser.add_argument(
+        "--require-production-approval",
+        action="store_true",
+        help="Fail unless a current explicit production approval is present.",
+    )
     parser.add_argument(
         "--json", action="store_true", help="Print the machine-readable review report."
     )
@@ -377,6 +394,17 @@ def main(argv: list[str] | None = None) -> int:
         ),
         expected_external_provider_subject=args.expected_external_provider_subject,
     )
+    required_boundary_scopes: set[str] = set()
+    if args.require_reference_readiness:
+        required_boundary_scopes.update(REFERENCE_READINESS_SCOPES)
+    if args.require_external_provider_proof:
+        required_boundary_scopes.add("external_providers")
+    if args.require_production_approval:
+        required_boundary_scopes.add("production_approval")
+    if required_boundary_scopes:
+        enforce_required_boundary_scopes(
+            report, required_scopes=required_boundary_scopes
+        )
     encoded = json.dumps(report, indent=2, sort_keys=True) + "\n"
     if args.output is not None:
         write_object(

tools/assessments/govoplan_assessment/__init__.py

@@ -1,10 +1,15 @@
 """Repeatable GovOPlaN product-assessment tooling."""
 
-from .capability_fit import review_capability_fit, render_review
+from .capability_fit import (
+    enforce_required_boundary_scopes,
+    render_review,
+    review_capability_fit,
+)
 from .evidence import collect_installed_composition
 
 __all__ = (
     "collect_installed_composition",
+    "enforce_required_boundary_scopes",
     "render_review",
     "review_capability_fit",
 )

tools/assessments/govoplan_assessment/boundary_evidence.py

@@ -0,0 +1,270 @@
+"""Issue sanitized, release-bound target evidence from retained result files."""
+
+from __future__ import annotations
+
+import base64
+from datetime import UTC, datetime, timedelta
+from pathlib import Path
+from typing import Any, Mapping, Sequence
+
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
+
+from .evidence import (
+    MAX_HASHED_FILE_BYTES,
+    NEGATIVE_RESULTS,
+    OPAQUE_ID_PATTERN,
+    POSITIVE_RESULTS,
+    PROOF_REQUIREMENTS,
+    _active_authority_keys,
+    _bounded_file_sha256,
+    canonical_bytes,
+    canonical_sha256,
+)
+
+
+MAX_BOUNDARY_ARTIFACT_BYTES = MAX_HASHED_FILE_BYTES
+MAX_BOUNDARY_ARTIFACT_TOTAL_BYTES = 512 * 1024 * 1024
+
+
+def issue_boundary_evidence(
+    *,
+    assessment: Mapping[str, Any],
+    installed_evidence: Mapping[str, Any],
+    proof_id: str,
+    claims: Sequence[Mapping[str, Any]],
+    authority_keyring: dict[str, Any],
+    signing_keys: Mapping[str, Ed25519PrivateKey],
+    expires_at: datetime,
+    issued_at: datetime | None = None,
+    expected_external_provider_subject: str | None = None,
+    forbidden_authority_public_keys: frozenset[bytes] = frozenset(),
+    release_origin_verified: bool = False,
+) -> dict[str, Any]:
+    """Build and sign one bounded proof after its release origin was verified.
+
+    The public CLI is responsible for deriving ``release_origin_verified`` from
+    the signed catalog, installed observation and installer receipt. Artifact
+    paths are consumed here and never copied into the resulting receipt.
+    """
+
+    if release_origin_verified is not True:
+        raise ValueError(
+            "boundary evidence requires independently verified installed release origin"
+        )
+    _require_opaque_id(proof_id, label="proof ID")
+    now = issued_at or datetime.now(tz=UTC)
+    now = _aware_utc(now, label="issuance time")
+    expiry = _aware_utc(expires_at, label="expiry time")
+    if now >= expiry:
+        raise ValueError("boundary evidence expiry must be after issuance")
+
+    assessment_id = assessment.get("assessment_id")
+    release = assessment.get("release")
+    assessment_release = release.get("ref") if isinstance(release, Mapping) else None
+    deployment = assessment.get("deployment_profile")
+    deployment_subject = (
+        deployment.get("id") if isinstance(deployment, Mapping) else None
+    )
+    _require_opaque_id(assessment_id, label="assessment ID")
+    _require_opaque_id(assessment_release, label="assessment release")
+    _require_opaque_id(deployment_subject, label="deployment subject")
+    if expected_external_provider_subject is not None:
+        _require_opaque_id(
+            expected_external_provider_subject,
+            label="external-provider subject",
+        )
+
+    normalized_claims = _normalize_claims(
+        claims=claims,
+        deployment_subject=str(deployment_subject),
+        expected_external_provider_subject=expected_external_provider_subject,
+    )
+    active_at_issue, issue_findings = _active_authority_keys(
+        authority_keyring=authority_keyring,
+        verification_time=now,
+        forbidden_public_keys=forbidden_authority_public_keys,
+    )
+    active_until_expiry, expiry_findings = _active_authority_keys(
+        authority_keyring=authority_keyring,
+        verification_time=expiry - timedelta(microseconds=1),
+        forbidden_public_keys=forbidden_authority_public_keys,
+    )
+    if issue_findings or expiry_findings:
+        raise ValueError(
+            "proof-authority keyring is malformed, reused, or not valid for the full proof interval"
+        )
+    if not signing_keys:
+        raise ValueError(
+            "at least one independently provisioned signing key is required"
+        )
+
+    covered_scopes: set[str] = set()
+    verified_signers: list[tuple[str, Ed25519PrivateKey]] = []
+    for key_id, private_key in sorted(signing_keys.items()):
+        _require_opaque_id(key_id, label="signing key ID")
+        if not isinstance(private_key, Ed25519PrivateKey):
+            raise ValueError("boundary signing keys must be Ed25519")
+        authority = active_at_issue.get(key_id)
+        authority_at_expiry = active_until_expiry.get(key_id)
+        public_bytes = private_key.public_key().public_bytes(
+            encoding=serialization.Encoding.Raw,
+            format=serialization.PublicFormat.Raw,
+        )
+        if (
+            authority is None
+            or authority_at_expiry is None
+            or authority[0] != public_bytes
+            or authority_at_expiry[0] != public_bytes
+        ):
+            raise ValueError(
+                f"signing key {key_id!r} is not independently authorized for the full proof interval"
+            )
+        covered_scopes.update(authority[1])
+        verified_signers.append((key_id, private_key))
+
+    claim_scopes = {str(claim["scope"]) for claim in normalized_claims}
+    uncovered_scopes = sorted(claim_scopes - covered_scopes)
+    if uncovered_scopes:
+        raise ValueError(
+            "no supplied signing key is authorized for scopes: "
+            + ", ".join(uncovered_scopes)
+        )
+
+    proof: dict[str, Any] = {
+        "$schema": "./capability-fit-boundary-evidence.schema.json",
+        "schema_version": "0.1.0",
+        "evidence_kind": "govoplan.capability-fit-boundary-proof",
+        "proof_id": proof_id,
+        "assessment_id": assessment_id,
+        "assessment_release": assessment_release,
+        "installed_evidence_sha256": canonical_sha256(installed_evidence),
+        "issued_at": _iso_datetime(now),
+        "expires_at": _iso_datetime(expiry),
+        "claims": normalized_claims,
+    }
+    signature_payload = canonical_bytes(proof)
+    proof["signatures"] = [
+        {
+            "algorithm": "ed25519",
+            "key_id": key_id,
+            "value": base64.b64encode(private_key.sign(signature_payload)).decode(
+                "ascii"
+            ),
+        }
+        for key_id, private_key in verified_signers
+    ]
+    return proof
+
+
+def _normalize_claims(
+    *,
+    claims: Sequence[Mapping[str, Any]],
+    deployment_subject: str,
+    expected_external_provider_subject: str | None,
+) -> list[dict[str, Any]]:
+    if not 1 <= len(claims) <= len(PROOF_REQUIREMENTS):
+        raise ValueError("boundary evidence requires between one and eight claims")
+    normalized: list[dict[str, Any]] = []
+    seen_scopes: set[str] = set()
+    total_bytes = 0
+    for claim in claims:
+        scope = str(claim.get("scope") or "")
+        if scope not in PROOF_REQUIREMENTS or scope in seen_scopes:
+            raise ValueError("boundary claim scopes must be known and unique")
+        seen_scopes.add(scope)
+        result = str(claim.get("result") or "")
+        if result not in {POSITIVE_RESULTS[scope], NEGATIVE_RESULTS[scope]}:
+            raise ValueError(f"boundary claim result is invalid for {scope!r}")
+        controls = _opaque_id_list(
+            claim.get("control_ids"),
+            label=f"{scope} control IDs",
+            maximum=256,
+        )
+        raw_artifacts = claim.get("artifacts")
+        if not isinstance(raw_artifacts, Sequence) or isinstance(
+            raw_artifacts, (str, bytes)
+        ):
+            raise ValueError(f"{scope} artifacts must be a non-empty list")
+        if not 1 <= len(raw_artifacts) <= 256:
+            raise ValueError(f"{scope} must reference between one and 256 artifacts")
+        artifacts: list[dict[str, str]] = []
+        seen_artifacts: set[str] = set()
+        for artifact in raw_artifacts:
+            if not isinstance(artifact, Mapping):
+                raise ValueError(f"{scope} contains a malformed artifact")
+            artifact_id = artifact.get("artifact_id")
+            _require_opaque_id(artifact_id, label=f"{scope} artifact ID")
+            artifact_id = str(artifact_id)
+            if artifact_id in seen_artifacts:
+                raise ValueError(f"{scope} contains duplicate artifact IDs")
+            seen_artifacts.add(artifact_id)
+            raw_path = artifact.get("path")
+            if not isinstance(raw_path, (str, Path)) or not str(raw_path):
+                raise ValueError(f"{scope} artifact {artifact_id!r} has no file path")
+            try:
+                digest, size, changed = _bounded_file_sha256(
+                    Path(raw_path), max_bytes=MAX_BOUNDARY_ARTIFACT_BYTES
+                )
+            except OSError as exc:
+                raise ValueError(
+                    f"could not securely hash {scope} artifact {artifact_id!r}"
+                ) from exc
+            if changed:
+                raise ValueError(
+                    f"{scope} artifact {artifact_id!r} changed or exceeded the size limit while hashing"
+                )
+            total_bytes += size
+            if total_bytes > MAX_BOUNDARY_ARTIFACT_TOTAL_BYTES:
+                raise ValueError(
+                    "boundary evidence artifacts exceed the total size limit"
+                )
+            artifacts.append({"artifact_id": artifact_id, "sha256": digest.hex()})
+        normalized.append(
+            {
+                "scope": scope,
+                "result": result,
+                "subject_id": (
+                    expected_external_provider_subject
+                    if scope == "external_providers"
+                    else deployment_subject
+                ),
+                "control_ids": controls,
+                "artifacts": artifacts,
+            }
+        )
+    if "external_providers" in seen_scopes and not expected_external_provider_subject:
+        raise ValueError(
+            "external-provider evidence requires its expected opaque subject ID"
+        )
+    return sorted(normalized, key=lambda item: str(item["scope"]))
+
+
+def _opaque_id_list(value: object, *, label: str, maximum: int) -> list[str]:
+    if not isinstance(value, Sequence) or isinstance(value, (str, bytes)):
+        raise ValueError(f"{label} must be a non-empty list")
+    result = [str(item) for item in value]
+    if not 1 <= len(result) <= maximum or len(result) != len(set(result)):
+        raise ValueError(f"{label} must contain unique bounded IDs")
+    for item in result:
+        _require_opaque_id(item, label=label)
+    return result
+
+
+def _require_opaque_id(value: object, *, label: str) -> None:
+    if (
+        not isinstance(value, str)
+        or len(value) > 160
+        or OPAQUE_ID_PATTERN.fullmatch(value) is None
+    ):
+        raise ValueError(f"{label} must be a bounded opaque ID")
+
+
+def _aware_utc(value: datetime, *, label: str) -> datetime:
+    if value.tzinfo is None:
+        raise ValueError(f"{label} must include a timezone")
+    return value.astimezone(UTC)
+
+
+def _iso_datetime(value: datetime) -> str:
+    return value.astimezone(UTC).isoformat().replace("+00:00", "Z")

tools/assessments/govoplan_assessment/capability_fit.py

@@ -930,10 +930,7 @@ def build_report(
     boundary_scope = (
         boundary_review.proof_scope
         if boundary_review is not None
-        else {
-            scope: {"checked": False, "valid": None}
-            for scope in PROOF_REQUIREMENTS
-        }
+        else {scope: {"checked": False, "valid": None} for scope in PROOF_REQUIREMENTS}
     )
     proof_scope = {
         "assessment_schema": {"checked": True, "valid": schema_valid},
@@ -1002,6 +999,63 @@ def build_report(
     }
 
 
+def enforce_required_boundary_scopes(
+    report: dict[str, Any], *, required_scopes: Iterable[str]
+) -> dict[str, Any]:
+    """Turn missing or negative external proof into an admission blocker."""
+
+    requested = tuple(dict.fromkeys(sorted(required_scopes)))
+    unknown = sorted(set(requested) - set(PROOF_REQUIREMENTS))
+    if unknown:
+        raise ValueError("unknown boundary scopes: " + ", ".join(unknown))
+    proof_scope = report.get("proof_scope")
+    if not isinstance(proof_scope, dict):
+        raise ValueError("capability-fit report has no proof scope")
+    failed = tuple(
+        scope
+        for scope in requested
+        if not isinstance(proof_scope.get(scope), dict)
+        or proof_scope[scope].get("checked") is not True
+        or proof_scope[scope].get("valid") is not True
+    )
+    proof_scope["admission"] = {
+        "checked": True,
+        "valid": not failed,
+        "required_scopes": list(requested),
+        "failed_scopes": list(failed),
+    }
+    if not failed:
+        return report
+    findings = report.setdefault("findings", [])
+    existing = {
+        (item.get("code"), item.get("message"))
+        for item in findings
+        if isinstance(item, dict)
+    }
+    for scope in failed:
+        message = (
+            f"Admission requires current positive boundary evidence for {scope!r}."
+        )
+        if ("required_boundary_scope_unsatisfied", message) not in existing:
+            findings.append(
+                {
+                    "severity": "blocker",
+                    "code": "required_boundary_scope_unsatisfied",
+                    "message": message,
+                    "assessment_ids": ["assessment.external_proof"],
+                }
+            )
+    findings.sort(
+        key=lambda item: (
+            _severity_rank(str(item.get("severity") or "")),
+            str(item.get("code") or ""),
+            str(item.get("message") or ""),
+        )
+    )
+    report["status"] = "blocked"
+    return report
+
+
 def render_review(report: dict[str, Any]) -> str:
     proof_scope = report.get("proof_scope", {})
     installed_scope = proof_scope.get("installed_artifacts", {})
@@ -1062,8 +1116,7 @@ def render_review(report: dict[str, Any]) -> str:
     unchecked_boundaries = [
         label
         for key, label in (
-            (scope, scope.replace("_", "-"))
-            for scope in PROOF_REQUIREMENTS
+            (scope, scope.replace("_", "-")) for scope in PROOF_REQUIREMENTS
         )
         if report.get("proof_scope", {}).get(key, {}).get("checked") is not True
     ]