Visual Basic 6.0

AES OFB Output Feedback Mode Encryption

See more Encryption Examples

Demonstrates how to encrypt using AES OFB (Output Feedback) mode. Visual Basic 6.0

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

Dim crypt As New ChilkatCrypt2

crypt.CryptAlgorithm = "aes"
' Set the cipher mode to Output Feedback
crypt.CipherMode = "ofb"
crypt.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.
crypt.EncodingMode = "hex"

Dim ivHex As String
ivHex = "000102030405060708090A0B0C0D0E0F"
crypt.SetEncodedIV ivHex,"hex"

' The secret key must equal the size of the key.  For
' 256-bit encryption, the binary secret key is 32 bytes.
Dim keyHex As String
keyHex = "603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4"
crypt.SetEncodedKey keyHex,"hex"

' Encrypt a string...
Dim encStr As String
encStr = crypt.EncryptStringENC("Popular opinions, on subjects not palpable to sense, are often true, but seldom or never the whole truth. -- John Stuart Mill")
Debug.Print encStr

Dim decrypt As New ChilkatCrypt2
decrypt.CryptAlgorithm = "aes"
decrypt.CipherMode = "ofb"
decrypt.KeyLength = 256
decrypt.EncodingMode = "hex"
decrypt.SetEncodedIV ivHex,"hex"
decrypt.SetEncodedKey keyHex,"hex"

' Now decrypt:
Dim decStr As String
decStr = decrypt.DecryptStringENC(encStr)
Debug.Print decStr