(Ruby) Duplicate .NET's Rfc2898DeriveBytes Functionality

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

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# 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)
# 
# 

crypt = Chilkat::CkCrypt2.new()

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..
saltHex = crypt.encodeString(salt,"utf-8","hex")

# Duplicate the test vector as shown above.
dkHex = crypt.pbkdf2("passwordPASSWORDpassword","utf-8","sha1",saltHex,4096,25 * 8,"hex")
print dkHex + "\n";