Function parseRawPublicKey

js/sign/src/utils/utils.ts:140–177

(
  type: SignatureType,
  rawPublicKey: Uint8Array
)

}

export function parseRawPublicKey(
  type: SignatureType,
  rawPublicKey: Uint8Array
): KeyObject {
  if (type === SignatureType.Ed25519) {
    const jwk = {
      kty: 'OKP',
      crv: 'Ed25519',
      x: Buffer.from(rawPublicKey).toString('base64url'),
    };
    return crypto.createPublicKey({ key: jwk, format: 'jwk' });
  } else if (type === SignatureType.EcdsaP256SHA256) {
    // Node.js doesn't have a built-in helper to parse raw ECDSA public key points synchronously
    // without manual ASN.1 wrapping. As a cleaner alternative, we uncompress the point, slice
    // the X and Y coordinates manually, and import it using the standardized JWK format.
    const uncompressedPub = crypto.ECDH.convertKey(
      rawPublicKey,
      'prime256v1',
      /*inputEncoding=*/ undefined,
      /*outputEncoding=*/ undefined,
      'uncompressed'
    ) as Buffer;

    // uncompressedPub is a 65-byte Buffer.
    // Byte 0 is the prefix (0x04), bytes 1-32 are X, bytes 33-64 are Y.
    const x = uncompressedPub.subarray(1, 33);
    const y = uncompressedPub.subarray(33, 65);

    const jwk = {
      kty: 'EC',
      crv: 'P-256',
      x: Buffer.from(x).toString('base64url'),
      y: Buffer.from(y).toString('base64url'),
    };
    return crypto.createPublicKey({ key: jwk, format: 'jwk' });
  }
  throw new Error('Unsupported signature type.');
}

export function calcWebBundleHash(webBundle: Uint8Array): Uint8Array {
  const hash = crypto.createHash('sha512');