C#

Duplicate .NET's Rfc2898DeriveBytes Functionality

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

//  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)
//  
//  

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

string 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..
string saltHex = crypt.EncodeString(salt,"utf-8","hex");

//  Duplicate the test vector as shown above.
string dkHex = crypt.Pbkdf2("passwordPASSWORDpassword","utf-8","sha1",saltHex,4096,25 * 8,"hex");
Debug.WriteLine(dkHex);