(Visual FoxPro) Duplicate .NET's Rfc2898DeriveBytes Functionality

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loCrypt
LOCAL lcSalt
LOCAL lcSaltHex
LOCAL lcDkHex

* 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)
* 
* 

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')

lcSalt = "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..
lcSaltHex = loCrypt.EncodeString(lcSalt,"utf-8","hex")

* Duplicate the test vector as shown above.
lcDkHex = loCrypt.Pbkdf2("passwordPASSWORDpassword","utf-8","sha1",lcSaltHex,4096,25 * 8,"hex")
? lcDkHex

RELEASE loCrypt