Visual FoxPro

Blowfish OFB Output Feedback Mode Encryption

See more Encryption Examples

Demonstrates how to encrypt using Blowfish OFB (Output Feedback) mode. Visual FoxPro

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.

loCrypt = CreateObject('Chilkat.Crypt2')

* Use "blowfish2" to produce correct results that match published blowfish test vectors.
loCrypt.CryptAlgorithm = "blowfish2"
* 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"

* The block size of the blowfish algoirthm is 8 bytes, therefore the IV is 8 bytes.
lcIvHex = "0001020304050607"
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("Emergencies have always been the pretext on which the safeguards of individual liberty have been eroded. -- Friedrich Hayek")
? lcEncStr

loDecrypt = CreateObject('Chilkat.Crypt2')
loDecrypt.CryptAlgorithm = "blowfish2"
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