Function ecExportKey

lib/internal/crypto/ec.js:90–132

(key, format)

}

function ecExportKey(key, format) {
  try {
    const handle = getCryptoKeyHandle(key);
    switch (format) {
      case kWebCryptoKeyFormatRaw: {
        return TypedArrayPrototypeGetBuffer(
          handle.exportECPublicRaw(POINT_CONVERSION_UNCOMPRESSED));
      }
      case kWebCryptoKeyFormatSPKI: {
        let spki = handle.export(kKeyFormatDER, kWebCryptoKeyFormatSPKI);
        // WebCrypto requires uncompressed point format for SPKI exports.
        // This is a very rare edge case dependent on the imported key
        // using compressed point format.
        // Expected SPKI DER byte lengths with uncompressed points:
        // P-256: 91 = 26 bytes of SPKI ASN.1 + 65-byte uncompressed point.
        // P-384: 120 = 23 bytes of SPKI ASN.1 + 97-byte uncompressed point.
        // P-521: 158 = 25 bytes of SPKI ASN.1 + 133-byte uncompressed point.
        // Difference in initial SPKI ASN.1 is caused by OIDs and length encoding.
        const { namedCurve } = getCryptoKeyAlgorithm(key);
        if (TypedArrayPrototypeGetByteLength(spki) !== {
          '__proto__': null, 'P-256': 91, 'P-384': 120, 'P-521': 158,
        }[namedCurve]) {
          const raw = handle.exportECPublicRaw(POINT_CONVERSION_UNCOMPRESSED);
          const tmp = new KeyObjectHandle();
          tmp.init(kKeyTypePublic, raw, kKeyFormatRawPublic,
                   'ec', null, namedCurve);
          spki = tmp.export(kKeyFormatDER, kWebCryptoKeyFormatSPKI);
        }
        return TypedArrayPrototypeGetBuffer(spki);
      }
      case kWebCryptoKeyFormatPKCS8: {
        return TypedArrayPrototypeGetBuffer(
          handle.export(kKeyFormatDER, kWebCryptoKeyFormatPKCS8, null, null));
      }
      default:
        return undefined;
    }
  } catch (err) {
    throw lazyDOMException(
      'The operation failed for an operation-specific reason',
      { name: 'OperationError', cause: err });
  }
}

function ecImportKey(
  format,