Perl

Duplicate PHP's openssl_encrypt and openssl_random_pseudo_bytes

See more OpenSSL Examples

Demonstrates how to duplicate PHP's openssl_encrypt function. (https://www.php.net/manual/en/function.openssl-encrypt.php) Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

# Duplicates thw following PHP script:

# $text = "This is a test";
# $passphrase = "my password";
# $iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length("AES-256-CBC"));
# $crypted = base64_encode($iv.openssl_encrypt($text, "AES-256-CBC", $passphrase, OPENSSL_RAW_DATA, $iv));
# echo $crypted;

my $crypt = Chilkat2::Crypt2->new;

my $text = 'This is a test';
my $passphrase = 'my password';

# AES is a block cipher.  The IV size for any block cipher is the size of the block, which is defined by the encryption algorithm.
# For AES, the block size is always 16 bytes, regardless of key size (i.e. 128-bits, 192-bits, or 256-bits).
# Therefore, generate 16 random bytes for the IV.
$crypt->EncodingMode('base64');
my $ivBase64 = $crypt->GenRandomBytesENC(16);

print 'Generated IV = ', $ivBase64, "\n";

# Because we're doing AES-256-CBC, the key length must be 256-bits (i.e. 32 bytes).
# Given that our passphrase is a us-ascii string that can be shorter or longer than 32-bytes, we need to
# somehow transform the passphrase to a 32-byte secret key.  We need to know what openssl_encrypt does.
# Here's the answer from the openssl_encrypt documentation:
#
# "If the passphrase is shorter than expected, it is silently padded with NUL characters;
# if the passphrase is longer than expected, it is silently truncated."

# OK.... so let's pad or shorten to get a 32-byte key.
my $bdKey = Chilkat2::BinData->new;
$bdKey->AppendString($passphrase, 'utf-8');

my $sz = $bdKey->NumBytes;
if ($sz > 32) {
    $bdKey->RemoveChunk(32, $sz - 32);
} else {
    $bdKey->Clear();
    $bdKey->AppendPadded($passphrase, 'utf-8', 0, 32);
}

# Setup for encryption.
$crypt->CryptAlgorithm('aes');
$crypt->KeyLength(256);
$crypt->SetEncodedIV($ivBase64, 'base64');
$crypt->SetEncodedKey($bdKey->GetEncoded('base64'), 'base64');

# Encrypt and base64 encode.
my $cipherText64 = $crypt->EncryptStringENC($text);

# The PHP code fragment above returns the base64 encoded bytes of the IV and the encrypted text.
# So let's do that..
my $bd = Chilkat2::BinData->new;
$bd->AppendEncoded($ivBase64, 'base64');
$bd->AppendEncoded($cipherText64, 'base64');
my $result = $bd->GetEncoded('base64');

print 'result = ', $result, "\n";

# Sample output:
# dN0vS1O0cWi5BbLAAY+NTf7bs3S27xzPf11RkG47sjs=

# Now let's decrypt from the output...

# Setup for decryption.
$crypt->CryptAlgorithm('aes');
$crypt->KeyLength(256);
$crypt->SetEncodedKey($bdKey->GetEncoded('base64'), 'base64');

my $bdResult = Chilkat2::BinData->new;
$bdResult->AppendEncoded($result, 'base64');
$crypt->SetEncodedIV($bdResult->GetEncodedChunk(0, 16, 'base64'), 'base64');

# Remove the IV (first 16 bytes) from the result.
$bdResult->RemoveChunk(0, 16);
my $success = $crypt->DecryptBd($bdResult);
my $originalText = $bdResult->GetString('utf-8');

print 'original text = ', $originalText, "\n";