Function verifyMessage

http/unstable_message_signatures.ts:921–1084

(
  message: Request | Response,
  keyLookup: (
    keyId: string,
    algorithm?: SignatureAlgorithm,
  ) => Promise<CryptoKey | null> | CryptoKey | null,
  options?: VerifyOptions,
)

 * @returns Array of verified signature results.
 */
export async function verifyMessage(
  message: Request | Response,
  keyLookup: (
    keyId: string,
    algorithm?: SignatureAlgorithm,
  ) => Promise<CryptoKey | null> | CryptoKey | null,
  options?: VerifyOptions,
): Promise<VerifyResult[]> {
  if (
    options?.maxAge !== undefined &&
    (!Number.isInteger(options.maxAge) || options.maxAge < 0)
  ) {
    throw new RangeError(
      `maxAge must be a non-negative integer, got ${options.maxAge}`,
    );
  }

  const sigInputHeader = message.headers.get("Signature-Input");
  if (sigInputHeader === null) {
    throw new TypeError('Missing "Signature-Input" header');
  }
  const sigHeader = message.headers.get("Signature");
  if (sigHeader === null) {
    throw new TypeError('Missing "Signature" header');
  }

  const sigInputDict = parseDictionary(sigInputHeader);
  const sigDict = parseDictionary(sigHeader);

  // Validate label consistency
  for (const [label] of sigInputDict) {
    if (!sigDict.has(label)) {
      throw new TypeError(
        `Label "${label}" found in Signature-Input but missing in Signature`,
      );
    }
  }
  for (const [label] of sigDict) {
    if (!sigInputDict.has(label)) {
      throw new TypeError(
        `Label "${label}" found in Signature but missing in Signature-Input`,
      );
    }
  }

  const results: VerifyResult[] = [];
  const now = Math.floor(Date.now() / 1000);

  for (const [label, sigInputMember] of sigInputDict) {
    // Filter by labels option
    if (options?.labels && !options.labels.includes(label)) continue;

    if (!isInnerList(sigInputMember)) {
      throw new TypeError(
        `Signature-Input member "${label}" is not an Inner List`,
      );
    }