mcrypt DES Encryption Testing Program

Cryptography Tutorials - Herong's Tutorial Examples

∟mcrypt DES Encryption Testing Program

This section provides a tutorial example on how to use the DES algorithm in a specific operation mode as block or stream cipher.

To test out the DES operation modes and stream cipher modes implemented in the "mcrypt" extension, I wrote the following test PHP script:

<?php # des_mcrypt_operation_mode_test.php
 * Copyright (c) HerongYang.com. All Rights Reserved.
# 
   $key = pack("H*", "0123456789ABCDEF");
   $iv = pack("H*", "1234567890ABCDEF");
   # "Now is the time for all "   
   $plain_text = pack("H*", 
      "4E6F77206973207468652074696D6520666F7220616C6C20");

   $mode = MCRYPT_MODE_ECB;
   $expected = pack("H*", 
      "3FA40E8A984D43156A271787AB8883F9893D51EC4B563B53");
   print("\n\nTest 1 - DES ECB 64-bit:");
   des_test($mode);

   $mode = MCRYPT_MODE_CBC;
   $expected = pack("H*", 
      "E5C7CDDE872BF27C43E934008C389C0F683788499A7C05F6");
   print("\n\nTest 2 - DES CBC 64-bit:");
   des_test($mode);

   $mode = MCRYPT_MODE_CFB; # 8-bit
   $expected = pack("H*", 
      "F31FDA07011462EE187F43D80A7CD9B5B0D290DA6E5B9A87");
   print("\n\nTest 3 - DES CFB 8-bit:");
   des_test($mode);

   $mode = MCRYPT_MODE_OFB; # 8-bit
   $expected = pack("H*", 
      "F34A2850C9C64985D684AD96D772E2F243EA499ABEE8AE95");
   print("\n\nTest 4 - DES OFB 8-bit:");
   des_test($mode);

function des_test($mode) {
   global $key, $iv, $plain_text, $expected;
   $cipher = mcrypt_module_open(MCRYPT_DES, '', $mode, '');
   mcrypt_generic_init($cipher, $key, $iv);
   $cipher_text = mcrypt_generic($cipher, $plain_text);
   mcrypt_generic_deinit($cipher);
   mcrypt_module_close($cipher);
   print("\nThe key       : ".bin2Hex($key));
   print("\nThe IV        : ".bin2Hex($iv));
   print("\nThe plaintext : ".bin2Hex($plain_text));
   print("\nThe ciphertext: ".bin2Hex($cipher_text));
   print("\nThe expected  : ".bin2Hex($expected));
}
?>

If you run this script, you should get:

Test 1 - DES ECB 64-bit:
The key       : 0123456789abcdef
The IV        : 1234567890abcdef
The plaintext : 4e6f77206973207468652074696d6520666f7220616c6c20
The ciphertext: 3fa40e8a984d48156a271787ab8883f9893d51ec4b563b53
The expected  : 3fa40e8a984d43156a271787ab8883f9893d51ec4b563b53

Test 2 - DES CBC 64-bit:
The key       : 0123456789abcdef
The IV        : 1234567890abcdef
The plaintext : 4e6f77206973207468652074696d6520666f7220616c6c20
The ciphertext: e5c7cdde872bf27c43e934008c389c0f683788499a7c05f6
The expected  : e5c7cdde872bf27c43e934008c389c0f683788499a7c05f6

Test 3 - DES CFB 8-bit:
The key       : 0123456789abcdef
The IV        : 1234567890abcdef
The plaintext : 4e6f77206973207468652074696d6520666f7220616c6c20
The ciphertext: f31fda07011462ee187f43d80a7cd9b5b0d290da6e5b9a87
The expected  : f31fda07011462ee187f43d80a7cd9b5b0d290da6e5b9a87

Test 4 - DES OFB 8-bit:
The key       : 0123456789abcdef
The IV        : 1234567890abcdef
The plaintext : 4e6f77206973207468652074696d6520666f7220616c6c20
The ciphertext: f34a2850c9c64985d684ad96d772e2f243ea499abee8ae95
The expected  : f34a2850c9c64985d684ad96d772e2f243ea499abee8ae95