(Visual FoxPro) Twofish OFB Output Feedback Mode Encryption

Demonstrates how to encrypt using Twofish OFB (Output Feedback) mode.

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

LOCAL loCrypt
LOCAL lcIvHex
LOCAL lcKeyHex
LOCAL lcEncStr
LOCAL loDecrypt
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')

loCrypt.CryptAlgorithm = "twofish"
* Set the cipher mode to Output Feedback
loCrypt.CipherMode = "ofb"
loCrypt.KeyLength = 256

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

lcIvHex = "000102030405060708090A0B0C0D0E0F"
loCrypt.SetEncodedIV(lcIvHex,"hex")

* The secret key must equal the size of the key.  For
* 256-bit encryption, the binary secret key is 32 bytes.
lcKeyHex = "603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4"
loCrypt.SetEncodedKey(lcKeyHex,"hex")

* Encrypt a string...
lcEncStr = loCrypt.EncryptStringENC("Without music to decorate it, time is just a bunch of boring production deadlines or dates by which bills must be paid. -- Frank Zappa")
? lcEncStr

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loDecrypt = CreateObject('Chilkat.Crypt2')
loDecrypt.CryptAlgorithm = "twofish"
loDecrypt.CipherMode = "ofb"
loDecrypt.KeyLength = 256
loDecrypt.EncodingMode = "hex"
loDecrypt.SetEncodedIV(lcIvHex,"hex")
loDecrypt.SetEncodedKey(lcKeyHex,"hex")

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

RELEASE loCrypt
RELEASE loDecrypt