Perl

AES XTS Mode

See more Encryption Examples

Demonstrates the AES-XTS mode of operation.

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

Perl

use chilkat();

$success = 0;

# 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 = chilkat::CkBinData->new();
$bd->AppendEncoded("2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0","hex");

$crypt = chilkat::CkCrypt2->new();

$crypt->put_CryptAlgorithm("aes");
$crypt->put_CipherMode("xts");
$crypt->put_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);

print "CT = " . $bd->getEncoded("hexlower") . "\r\n";

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

print "PT = " . $bd->getEncoded("hexlower") . "\r\n";

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