Perl

AES Encrypt and Decrypt a File

_LANGUAGE_ demonstrates how to AES encrypt a file of any size, and then decrypt. Perl

use chilkat();

$success = 0;

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

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

$crypt->put_CryptAlgorithm("aes");

# CipherMode may be "ecb" or "cbc"
$crypt->put_CipherMode("cbc");

# KeyLength may be 128, 192, 256
$crypt->put_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->put_PaddingScheme(0);

# 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.
$ivHex = "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.
$keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F";
$crypt->SetEncodedKey($keyHex,"hex");

# Encrypt a file, producing the .aes as output.
# The input file is unchanged, the output .aes contains the encrypted
# contents of the input file.

# Note: The .aes output file has no file format.  It is simply a stream
# of bytes that resembles random binary data.
$inFile = "/Users/chilkat/testData/pdf/sample.pdf";
$outFile = "/Users/chilkat/testData/p7m/sample.pdf.aes";
$success = $crypt->CkEncryptFile($inFile,$outFile);
if ($success != 1) {
    print $crypt->lastErrorText() . "\r\n";
    exit;
}

# For demonstration purposes, a different instance of the object will be used
# for decryption.
$decrypt = chilkat::CkCrypt2->new();

# All settings must match to be able to decrypt:
$decrypt->put_CryptAlgorithm("aes");
$decrypt->put_CipherMode("cbc");
$decrypt->put_KeyLength(256);
$decrypt->put_PaddingScheme(0);
$decrypt->SetEncodedIV($ivHex,"hex");
$decrypt->SetEncodedKey($keyHex,"hex");

# Decrypt the .aes
$inFile = "/Users/chilkat/testData/p7m/sample.pdf.aes";
$outFile = "/Users/chilkat/testData/pdf/recovered.pdf";
$success = $decrypt->CkDecryptFile($inFile,$outFile);
if ($success == 0) {
    print $decrypt->lastErrorText() . "\r\n";
    exit;
}

print "Success!" . "\r\n";