(VB.NET) AES CFB Mode Encryption

Demonstrates how to encrypt using AES CFB (Cipher Feedback) mode.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Dim crypt As New Chilkat.Crypt2

crypt.CryptAlgorithm = "aes"
crypt.CipherMode = "cfb"
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 = "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 = "603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4"
crypt.SetEncodedKey(keyHex,"hex")

' Encrypt a string...
Dim encStr As String = crypt.EncryptStringENC("Good night, good night! parting is such sweet sorrow, That I shall say good night till it be morrow. --  William Shakespeare")
Debug.WriteLine(encStr)

Dim decrypt As New Chilkat.Crypt2

decrypt.CryptAlgorithm = "aes"
decrypt.CipherMode = "cfb"
decrypt.KeyLength = 256
decrypt.EncodingMode = "hex"
decrypt.SetEncodedIV(ivHex,"hex")
decrypt.SetEncodedKey(keyHex,"hex")

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