(Visual FoxPro) 3DES Encryption, ECB, CBC modes

3DES encryption. The Chilkat encryption component supports Triple-DES in both ECB (Electronic Cookbook) and CBC (Cipher-Block Chaining) cipher modes.

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

LOCAL loCrypt
LOCAL lcIvHex
LOCAL lcKeyHex
LOCAL lcEncStr
LOCAL lcDecStr

* This example assumes the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

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

* Specify 3DES for the encryption algorithm:
loCrypt.CryptAlgorithm = "3des"

* CipherMode may be "ecb" or "cbc"
loCrypt.CipherMode = "cbc"

* KeyLength must be 192.  3DES is technically 168-bits;
* the most-significant bit of each key byte is a parity bit,
* so we must indicate a KeyLength of 192, which includes
* the parity bits.
loCrypt.KeyLength = 192

* The padding scheme determines the contents of the bytes
* that are added to pad the result to a multiple of the
* encryption algorithm's block size.  3DES has a block
* size of 8 bytes, so encrypted output is always
* a multiple of 8.
loCrypt.PaddingScheme = 0

* EncodingMode specifies the encoding of the output for
* encryption, and the input for decryption.
* It may be "hex", "url", "base64", or "quoted-printable".
loCrypt.EncodingMode = "hex"

* An initialization vector is required if using CBC or CFB modes.
* ECB mode does not use an IV.
* The length of the IV is equal to the algorithm's block size.
* It is NOT equal to the length of the key.
lcIvHex = "0001020304050607"
loCrypt.SetEncodedIV(lcIvHex,"hex")

* The secret key must equal the size of the key.  For 
* 3DES, the key must be 24 bytes (i.e. 192-bits).
lcKeyHex = "000102030405060708090A0B0C0D0E0F0001020304050607"
loCrypt.SetEncodedKey(lcKeyHex,"hex")

* Encrypt a string...
* The input string is 44 ANSI characters (i.e. 44 bytes), so
* the output should be 48 bytes (a multiple of 8).
* Because the output is a hex string, it should
* be 96 characters long (2 chars per byte).
lcEncStr = loCrypt.EncryptStringENC("The quick brown fox jumps over the lazy dog.")
? lcEncStr

* Now decrypt:
lcDecStr = loCrypt.DecryptStringENC(lcEncStr)
? lcDecStr

RELEASE loCrypt