(VB.NET) AES Encryption

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AES encryption. The Chilkat encryption component supports 128-bit, 192-bit, and 256-bit AES encryption in ECB (Electronic Cookbook), CBC (Cipher-Block Chaining), and other modes.

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

Dim crypt As New Chilkat.Crypt2

' AES is also known as Rijndael.		
crypt.CryptAlgorithm = "aes"

' CipherMode may be "ecb", "cbc", "ofb", "cfb", "gcm", etc.
' Note: Check the online reference documentation to see the Chilkat versions
' when certain cipher modes were introduced.
crypt.CipherMode = "cbc"

' KeyLength may be 128, 192, 256
crypt.KeyLength = 256

' The padding scheme determines the contents of the bytes
' that are added to pad the result to a multiple of the
' encryption algorithm's block size.  AES has a block
' size of 16 bytes, so encrypted output is always
' a multiple of 16.
crypt.PaddingScheme = 0

' EncodingMode specifies the encoding of the output for
' encryption, and the input for decryption.
' It may be "hex", "url", "base64", or "quoted-printable".
crypt.EncodingMode = "hex"

' An initialization vector is required if using CBC mode.
' ECB mode does not use an IV.
' The length of the IV is equal to the algorithm's block size.
' It is NOT equal to the length of the key.
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.
' For 128-bit encryption, the binary secret key is 16 bytes.
Dim keyHex As String = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"
crypt.SetEncodedKey(keyHex,"hex")

' Encrypt a string...
' The input string is 44 ANSI characters (i.e. 44 bytes), so
' the output should be 48 bytes (a multiple of 16).
' Because the output is a hex string, it should
' be 96 characters long (2 chars per byte).
Dim encStr As String = crypt.EncryptStringENC("The quick brown fox jumps over the lazy dog.")
Debug.WriteLine(encStr)

' This is the encrypted output in hex format:
' 4846F83AA211E239AA62A21F527F089EE9DDBEAD30EE15D4E79B607A621B97BEDB9B6F00A9B21F1B43A50B4C1BE0EDF2

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

' This is the decrypted string:
' The quick brown fox jumps over the lazy dog.