(VB.NET UWP/WinRT) AES OFB Output Feedback Mode Encryption

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

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' 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"
' 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 = "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("Popular opinions, on subjects not palpable to sense, are often true, but seldom or never the whole truth. -- John Stuart Mill")
Debug.WriteLine(encStr)

Dim decrypt As New Chilkat.Crypt2
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 = decrypt.DecryptStringENC(encStr)
Debug.WriteLine(decStr)