Dart

Duplicate .NET's Rfc2898DeriveBytes Functionality

See more Encryption Examples

Demonstrates how to duplicate the results produced by .NET's System.Security.Cryptography.Rfc2898DeriveBytes class. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example assumes Chilkat Crypt2 to have been previously unlocked.
  // See Unlock Crypt2 for sample code.

  // This example demonstrates how to duplicate the results produced
  // by .NET's System.Security.Cryptography.Rfc2898DeriveBytes class.

  // For example, here is C# code that transforms a password string into
  // bytes that can be used as a secret key for symmetric encryption (such as AES, blowfish, 3DES, etc.)
  // 
  //     Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes("secret", System.Text.Encoding.UTF8.GetBytes("saltsalt123"), numIterations);
  //     byte[] secretKeyBytes = deriveBytes.GetBytes(numBytes);

  // (The Rfc2898DeriveBytes computation is really just the PBKDF2 algorithm with SHA-1 hashing.)
  // In Chilkat, this is what we do to match...

  // First, let's get a test vector with known results.  Both Chilkat AND Microsoft should produce
  // the same results.  RFC 6070 has some PBKDF2 HMAC-SHA1 Test Vectors.  Here is one of them:

  //      Input:
  //        P = "passwordPASSWORDpassword" (24 octets)
  //        S = "saltSALTsaltSALTsaltSALTsaltSALTsalt" (36 octets)
  //        c = 4096
  //        dkLen = 25
  // 
  //      Output:
  //        DK = 3d 2e ec 4f e4 1c 84 9b
  //             80 c8 d8 36 62 c0 e4 4a
  //             8b 29 1a 96 4c f2 f0 70
  //             38                      (25 octets)
  // 
  // 

  final crypt = CkCrypt2();

  final salt = 'saltSALTsaltSALTsaltSALTsaltSALTsalt';
  // Given that the salt is really binary data (can be any random bunch of bytes),
  // we must pass the exact hex string representation of the salt bytes.
  // In this case, we're getting the utf-8 byte representation of our salt string,
  // which is identical to the us-ascii byte representation because there are no 8bit chars..
  final saltHex = crypt.encodeString(salt, 'utf-8', 'hex');

  // Duplicate the test vector as shown above.
  final dkHex = crypt.pbkdf2('passwordPASSWORDpassword', 'utf-8', 'sha1', saltHex, 4096, 25 * 8, 'hex');
  print(dkHex);
}