Dart Requires Chilkat v11.0.0+

How to Generate a JSON Web Key (JWK)

See more JSON Web Signatures (JWS) Examples

Demonstrates how to generate the following types of JSON Web Keys:

• RSA key pair
• EC key pair
• Octet sequence key (HMAC-256)
• 192-bit AES GCM key

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // ----------------------------------------------
  // Generate an RSA key pair in JWK format.
  // (Examples for generating other key types are shown below...)
  final rsa = CkRsa();
  final rsaKey = CkPrivateKey();
  try {
    rsa.genKey(2048, rsaKey);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final rsaJwkStr = rsaKey.getJwk();

  // The string returned is the most compact possible, and therefore it is not
  // very readable.  To pretty-print, load into a JSON object and emit..
  final json = CkJsonObject();
  json.emitCompact = false;
  json.load(rsaJwkStr);
  print(json.emit());

  // Sample RSA JWK:

  // { 
  //   "kty": "RSA",
  //   "n": "6w1Xpof7gKmytJ3yc_yjI5_K3MvVXnBYBDy5Oh2W6Xqu_fOl3W18SjS2AU5xJrTHlB_j84yQjPyXJh_ixjACK4K4dCSYqlLmn3R7QJ84vnHLIEkqwUICqOHdCBjK5xhMrdZxIhuNlJzbARY-3u9RqjsT3HYTjA6JNHUWTYBBRou4gYGm4cJgvX4uexdikqxnze014RmZMaOV_4MR--WL4G8QfNJ2pRBEXQeKyije89H6M5oTSK7KZqFTIqu9hwNtx2oGpGAIcS0Jv5xVl-hDtwXZNwQJaOxMzLw1nwnb2kMliJa67EabQFrQY_xthQNsfzcHJJlpqYiMprW8wRkzmQ",
  //   "e": "AQAB",
  //   "d": "1_bnXMw-SeYhmxAwb19lqVqtMpdaES5ZwHLmoT4EpbsiQ5T1BfENrMSnoaWoEy8w3Kk8cU7qlY-TdOUBIKWFqOKvhY8GciA_Y6zLfgGNSnYVczGmxfBXr0HvKvxUmWZbNbH9OqBkQnKoSmRdGcp7l1Q2mG4o4ZuNdxRJjKXV0_DTrNLUJzst0hsfoZ6mWUrQcn39XGvvLjz9ySS-DYGI1vli3ayx8jVNuw0rU8UXVs9WmPQLvZO_ZDMhoLEeKsdejnNkUNPAUjqxcSOZRojt4BfCmbt-_1slFb0NsoaqnDVZGezd9J9ocxGuyIWHAJu9GGZEcdaFyiDDs_WA1IS_fQ",
  //   "p": "9dU8f6yOklRcpV6ayVMKpyQ6AMuBTF3rZmB498eAvvTkVG1-upm8IkikTVNpPjEalc82Sxuq8oF4N5x1-F33sgVEoCZG-1WFZTn-rnPnXSALES9hqSaVYEwnh61EiY8ckjBVr9jD2nL1JKdbfgVVeo69-9PdjnKYYDVL8eLNPwM",
  //   "q": "9MX2sW0GyaOsZ86AYe3eG2ZgcgKHvhJa573gih5Jvi2e-Nv-L0EVK29_DA7n0Pjm-gl9zVAsGsMMkphJyEF9QgyUlJ-59XLqWnECS5gO6WZdtHrJxVvcO-_AOrLIxeYnYcwhmaVaxs_UEpqGzupKHCWgf4cfXe49lrIsqGKH4jM",
  //   "dp": "IQgj9uvSxGq9gCL0HXUhC1Bc0tqFZyN_i-QOnQybig0R2R5VVvFtTBYCrbk1fPvQHK0ZGIKBN9CZvK8zUsodjDgU_ofmJcNaBz4BsKM2RVcW5Zo-PyJGFAhnj12CxhEKv8Hq4ZP4zROBSQmLy6Uf1TX05S-Up51SSCshJ0FYXs0",
  //   "dq": "RijsMiUfGfL5OvP85pUI4e-xW1yQThHyzpQlZVGTL5jiBVEBhcfw6ndWAj3Pgp2ljyvjTFNboPwhgW93Tpg-8AytFgDGi605sVzNHJ_kPlBiMZY0eYaAFQn-npSaaecziJu7UdAMugneLsruMycCwRij7Ynsmr7sFmLR3B4J9vM",
  //   "qi": "jZE-a1pa8YjflpCSH5oqp1f6f6I6-hpZcLdamLCoAcjVSIPk86gtXtOFES4411-DqYzYIZM6B_g_SRYY6JpKAOuZ40mmMTlnIEoVf8BHiGl3g6bBAiN1yQGXrwXJsg2OYnocyRA-xWNdcMSSFA52SwEdar2Mmw29qVzxtC1QbpA"
  // }

  // ----------------------------------------------
  // Generate an EC P-256 key pair in JWK format

  final prng = CkPrng();
  final ecc = CkEcc();
  final ecKey = CkPrivateKey();
  ecc.genKey('P-256', prng, ecKey);

  final ecJwkStr = ecKey.getJwk();
  json.load(ecJwkStr);
  print(json.emit());

  // Sample EC JWK Key:
  // { 
  //   "kty": "EC",
  //   "crv": "P-256",
  //   "x": "tDeeYABgKEAbWicYPCEEI8sP4SRIhHKcHDW7VqrB4LA",
  //   "y": "J08HOoIZ0rX2Me3bNFZUltfxIk1Hrc8FsLu8VaSxsMI",
  //   "d": "-bqt1T0wNAN8sP5ruycQZRVlMlt3V_dSwlJ60xAX5io"
  // }

  // ----------------------------------------------
  // Octet sequence keys are intended for representing secret keys, such as HMAC keys and AES keys.

  // We'll use crypt to generate a random UUID..
  final crypt = CkCrypt2();

  // AES and HMAC keys are simply random arrays of bytes
  // For these, we can just build the JSON directly,
  // with the help of the PRNG object.

  final jwkHmac = CkJsonObject();
  jwkHmac.emitCompact = false;

  // Generate a 256-bit HMAK key (32 bytes)
  jwkHmac.appendString('kty', 'oct');
  // Give the key an optional ID, which can be anything, even strings as simple as "1", "2", etc.
  jwkHmac.appendString('kid', crypt.generateUuid());
  // Indicate the intended key alg (optional)
  jwkHmac.appendString('alg', 'HS256');
  // Generate the actual key bytes
  jwkHmac.appendString('k', prng.genRandom(32, 'base64url'));

  print(jwkHmac.emit());

  // Sample HMAC-256 JWK:

  // { 
  //   "kty": "oct",
  //   "kid": "06c2515d-41fb-e436-e405-3abb361f5f7a",
  //   "alg": "HS256",
  //   "k": "wR32w7yiMe5Lhb1vkW2koBpoMxpXTFYuxOYCCIEKjdE"
  // }

  // ----------------------------------------------
  // Now generate a 192-bit (24 byte) key that could be used with AES192GCM

  final jwkAes = CkJsonObject();
  jwkAes.emitCompact = false;

  jwkAes.appendString('kty', 'oct');
  jwkAes.appendString('kid', '2');
  jwkAes.appendString('k', prng.genRandom(24, 'base64url'));

  print(jwkAes.emit());

  // Sample AES key:
  // { 
  //   "kty": "oct",
  //   "kid": "2",
  //   "k": "akAkq-L_ZTZ6-tEIhDUMtU2ENhsEgL-p"
  // }
}