(PowerShell) AES XTS Mode

Demonstrates the AES-XTS mode of operation.

Note: This example requires Chilkat v9.5.0.91 or greater.

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Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

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

# Here we have a sample from CAVS validatition data:

# COUNT = 301
# DataUnitLen = 200
# Key = 
# 394c97881abd989d29c703e48a72b397
# a7acf51b59649eeea9b33274d8541df4
# i = 4b15c684a152d485fe9937d39b168c29
# PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0
# CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e

# Note: The above sample requires an AES-XTS implementation that fully supports ciphertext-stealing
# because the data to be encrypted is not an even multiple of the AES block size (i.e. not a multiple of 16 bytes).
# Chilkat fully supports AES-XTS with ciphertext stealing.
# (i.e. Chilkat implements XEX-based tweaked-codebook mode with ciphertext stealing (XTS))

$key = "394c97881abd989d29c703e48a72b397"
$tweakKey = "a7acf51b59649eeea9b33274d8541df4"
$dataUnit = "4b15c684a152d485fe9937d39b168c29"

$bd = New-Object Chilkat.BinData
$bd.AppendEncoded("2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0","hex")

$crypt = New-Object Chilkat.Crypt2

$crypt.CryptAlgorithm = "aes"
$crypt.CipherMode = "xts"
$crypt.KeyLength = 128

$crypt.SetEncodedKey($key,"hex")
$crypt.XtsSetEncodedTweakKey($tweakKey,"hex")
$crypt.XtsSetEncodedTweakValue($dataUnit,"hex")

# In-place encrypt the contents of bd.
$success = $crypt.EncryptBd($bd)

$("CT = " + $bd.GetEncoded("hexlower"))

# Decrypt to revert back to the unencrypted content:
$success = $crypt.DecryptBd($bd)

$("PT = " + $bd.GetEncoded("hexlower"))

# Output:
# CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e
# PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0