{
  "schema": "varexis-public-evidence-record/0.3",
  "generated_at_utc": "2026-10-25T20:55:19.974986+00:00",
  "record_id": "VXI-EXT-PROCUREMENT-HTTP-SIGNATURE-RESPONSE-REQUEST-CONTEXT-01-v1",
  "record_kind": "external_reference",
  "title": "HTTP response signature request context",
  "system": "IETF RFC 9421",
  "evidence_family": "vendor_evidence_review",
  "index_status": "PUBLIC_SAFE_SOURCE_REVIEW",
  "evidence_state": "PRIMARY_DOCUMENTATION_REVIEW_ONLY",
  "canonical_question": "Can a response signature using req be validated after the original request components have been discarded?",
  "near_questions": [
    "What must be retained to verify req components in a signed response?",
    "Does the response repeat every request value covered by its signature?",
    "Can a proxy-altered request prevent response signature validation?",
    "How does an HTTP signature distinguish request from response fields?"
  ],
  "supported_claims": [
    {
      "claim": "RFC 9421 permits a response signature to cover components from the triggering request using the req parameter. Those values are not repeated in the response, so the requester must retain the original components long enough to validate it. Proxy changes can prevent a match. A response signature alone does not reconstruct discarded request context.",
      "reliance": "DOCUMENTED_CAPABILITY_ONLY"
    }
  ],
  "not_demonstrated_claims": [
    "The signed response does not repeat original component values; proxy alterations and exact request context matter.",
    "Buyer implementation, live runtime enforcement, settled payment, physical outcome, certification or permission to act are not established.",
    "No expanded capabilities or licences for existing INDEX executables."
  ],
  "public_summary": "RFC 9421 permits a response signature to cover components from the triggering request using the req parameter. Those values are not repeated in the response, so the requester must retain the original components long enough to validate it. Proxy changes can prevent a match. A response signature alone does not reconstruct discarded request context.",
  "related_record_ids": [],
  "source_review": {
    "source_type": "official_external_documentation",
    "source_title": "IETF RFC 9421",
    "source_url": "https://www.rfc-editor.org/rfc/rfc9421.txt",
    "checked_on": "2026-10-25",
    "candidate_record_id": "VXI-EXT-PROCUREMENT-HTTP-SIGNATURE-RESPONSE-REQUEST-CONTEXT-01-v1",
    "candidate_record_sha256": "262f47c511f648bf1a166f13a1e6df323a81c890d65b182eb151128b043f51f8",
    "method": "Primary documentation reviewed for the published bounded statement.",
    "deployment_tested_by_varexis": false,
    "revalidation": "The delivered snapshot preserves the review date shown. Recheck current primary documentation and deployment context before relying on present applicability; payment does not trigger fresh research."
  },
  "answer_policy": {
    "classification": "DOCUMENTED_WITH_DEPLOYMENT_BOUNDARY",
    "bounded_answer": "RFC 9421 permits a response signature to cover components from the triggering request using the req parameter. Those values are not repeated in the response, so the requester must retain the original components long enough to validate it. Proxy changes can prevent a match. A response signature alone does not reconstruct discarded request context.",
    "required_buyer_context": "Original request components; Response Signature-Input with req flags; Intermediary transformations. Buyer deployment not inspected.",
    "missing_evidence": "A broader claim needs evidence matching the intended use. Payment does not upgrade the evidence state."
  },
  "private_boundary": "Raw logs, thresholds, private paths, source code, protected mechanisms and reconstruction-level details are excluded from public and paid delivery.",
  "decision_profile": {
    "schema": "varexis-vendor-evidence-review/1",
    "review_status": "documentation_review_only",
    "checked_on": "2026-10-25",
    "claim_to_check": "Can a response signature using req be validated after the original request components have been discarded?",
    "documented_statement": {
      "status": "documented",
      "statement": "RFC 9421 permits a response signature to cover components from the triggering request using the req parameter. Those values are not repeated in the response, so the requester must retain the original components long enough to validate it. Proxy changes can prevent a match. A response signature alone does not reconstruct discarded request context.",
      "source_ids": [
        "rfc9421"
      ]
    },
    "review_inference": {
      "status": "review_inference",
      "statement": "Retain the request components needed to validate a response signature using req. This is a documentation-review judgment, not an observed deployment outcome.",
      "source_ids": [
        "rfc9421"
      ]
    },
    "buyer_evidence_required": [
      "Original request components",
      "Response Signature-Input with req flags",
      "Intermediary transformations"
    ],
    "review_condition": {
      "status": "varexis_review_policy",
      "statement": "Refuse buyer-specific assurance from documentation alone. The signed response does not repeat original component values; proxy alterations and exact request context matter."
    },
    "unknowns": "The buyer implementation, effective configuration, complete evidence inventory and actual business outcome were not inspected.",
    "unknown_finding": {
      "status": "unknown",
      "statement": "The buyer implementation, effective configuration, complete evidence inventory and actual business outcome were not inspected."
    },
    "evidence_sources": [
      {
        "source_id": "rfc9421",
        "url": "https://www.rfc-editor.org/rfc/rfc9421.txt",
        "final_url": "https://www.rfc-editor.org/rfc/rfc9421.txt",
        "status": 200,
        "captured_at_utc": "2026-10-25T20:26:12.767Z",
        "sha256": "612655786bf4293bfc486e4177571467fbb3de6e6f0eea90cb74c346a34fdf3c",
        "bytes": 241160,
        "title": "IETF RFC 9421",
        "hash_basis": "SHA-256 of unmodified HTTP response body bytes",
        "rights_review": "Original factual paraphrase of the cited IETF RFC; IETF Trust and contributor rights remain applicable. No RFC text, code component or modified standard is redistributed.",
        "checked_on": "2026-10-25",
        "capture_status": 200,
        "claim_review_completed": true,
        "reviewed_sections": [
          "3.2.1",
          "7.2.1",
          "7.2.2",
          "2.4",
          "7.2.5",
          "7.2.6",
          "7.3.4",
          "7.2.8",
          "7.4.3"
        ],
        "version_context": "Fixed IETF RFC 9421 publication; later applicable updates and actual implementation conformance require separate review."
      }
    ],
    "observed_deployment": false,
    "commercial_reliance_boundary": "Documentation review only; the buyer must establish applicability and actual outcomes. INDEX does not inspect or control the deployment.",
    "paid_value": {
      "decision_context": "Retain the request components needed to validate a response signature using req.",
      "free": "Complete review, practical questions, sources and limitations; may be saved locally.",
      "single_request": "Existing server-saved version-bound route snapshot for later authenticated retrieval.",
      "evidence_receipt": "The same snapshot plus the existing unsigned delivery receipt.",
      "excluded": [
        "Fresh vendor research",
        "Continuous monitoring or change alerts",
        "Testing the buyer configuration",
        "Private evidence or vendor certification"
      ],
      "integrity": "Hashes identify content versions; they do not prove truth or provide a signature."
    },
    "revalidation": {
      "trigger": "A saved purchase does not recheck the source or buyer configuration.",
      "specific_watch": "Recheck 2.4 in IETF RFC 9421 when the source, applicable version, configuration or intended reliance changes. A detected change creates a review candidate, not automatic approval."
    },
    "buyer_relevance": "Retain the request components needed to validate a response signature using req.",
    "refusal_conditions": [
      "Refuse buyer-specific assurance from documentation alone. The signed response does not repeat original component values; proxy alterations and exact request context matter."
    ]
  },
  "niche": {
    "niche_id": "agent-authority-action-evidence",
    "label": "Agent Authority & Action Evidence",
    "classification_id": "audit",
    "classification_label": "Audit, Provenance & Evidence Accountability",
    "topic_id": "audit",
    "buyer_intent": "Retain the request components needed to validate a response signature using req.",
    "comparison_role": "supplementary_discovery"
  },
  "paid_access_note": "The full published answer and boundaries are free. Paid access saves the selected route and source versions, with an unsigned receipt when purchased. Preview coverage before paying. Fresh research, bespoke assessment and protected evidence are excluded.",
  "service_route": {
    "request_guide": "/varexis-index/request.html",
    "request_workflow": "/varexis-index/request-workflow.json",
    "service_id": "single_request",
    "service_routes_url": "/varexis-index/service-routes.json",
    "payment_required": true,
    "availability_endpoint": "/api/index/capabilities",
    "operational_status": "AUTOMATIC_SERVICE_CAPABILITIES_GATED",
    "checkout_url": "/index-access"
  },
  "authority_boundary": "VAREXIS-INDEX informs evidence reliance. It does not provide advice, certification, deployment authority, security assurance, production approval, or guarantee.",
  "human_page": "/varexis-index/catalog.html#http-signature-response-request-context",
  "machine_readable_record": "/varexis-index/records/http-signature-response-request-context.json"
}