Lianja

Blowfish OFB Output Feedback Mode Encryption

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

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

loCrypt = createobject("CkCrypt2")

// 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("CkCrypt2")
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