(PHP Extension) Example for both AES-128 and ChaCha20 to Encrypt Binary Data

Demonstrates the use of the new EncryptBd and DecryptBd methods introduced in Chilkat v9.5.0.67 to encrypt/decrypt binary bytes.

Note: This example requires Chilkat v9.5.0.67 or greater.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

// Load a small JPG file to be encrypted/decrypted.
$jpgBytes = new CkBinData();
$success = $jpgBytes->LoadFile('qa_data/jpg/starfish.jpg');
if ($success != true) {
    print 'Failed to load JPG file.' . "\n";
    exit;
}

// Show the unencrypted JPG bytes in Base64 format.
// (The "base64_mime" encoding was added in Chilkat v9.5.0.67.
// The "base64" encoding emits a single line of base64, whereas
// "base64_mime" will emit multi-line base64 as it would appear
// in MIME.)
print $jpgBytes->getEncoded('base64_mime') . "\n";

// Sample base64_mime JPG data:

// 	/9j/4AAQSkZJRgABAgEASABIAAD/7Q18UGhvdG9zaG9wIDMuMAA4QklNA+0AAAAAABAASAAAAAEA
// 	AQBIAAAAAQABOEJJTQPzAAAAAAAIAAAAAAAAAAE4QklNBAoAAAAAAAEAADhCSU0nEAAAAAAACgAB
// 	AAAAAAAAAAI4QklNA/UAAAAAAEgAL2ZmAAEAbGZmAAYAAAAAAAEAL2ZmAAEAoZmaAAYAAAAAAAEA
// 	MgAAAAEAWgAAAAYAAAAAAAEANQAAAAEALQAAAAYAAAAAAAE4QklNBBQAAAAAAAQAAAABOEJJTQQM
// 	...

$crypt = new CkCrypt2();

// Specify the encryption to be used.
// First we'll do AES-128 CBC
$crypt->put_CryptAlgorithm('aes');
$crypt->put_CipherMode('cbc');
$crypt->put_KeyLength(128);

$ivHex = '000102030405060708090A0B0C0D0E0F';
$crypt->SetEncodedIV($ivHex,'hex');

$keyHex = '000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F';
$crypt->SetEncodedKey($keyHex,'hex');

// Do the in-place 128-bit AES CBC encryption.
// The contents of jpgBytes are replaced with the encrypted bytes.
$success = $crypt->EncryptBd($jpgBytes);
if ($success != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

// Examine the JPG bytes again.  The bytes should be different because they are encrypted:
print $jpgBytes->getEncoded('base64_mime') . "\n";

// Sample base64_mime encrypted JPG data:

// 	sbz0babt1WCkQf5xKMdg/baZAcUBO5GVUUDF2BjVqmd+HrqKN+t6hAcqakL/bdo0q9hYmow0Tp1e
// 	AQ9V9DOiifQUZqWVkR+kL/c45bq8JGFDvgNl0djPt+yYhV789IB/fPH0upx+/ad++WNOlv1IxGMr
// 	Y1x1oERU/IsiEzafUJdI4kZ6FQo2IPGMF/Rm1h79I7hP1yYUFxvJyz+PzaySAUH1nLsNHyDVY5VY
// 	O90aH3steRSYbz8C8UF9wQ3qqEIXQNnnixvoNDnmHyY39VoVBI5F6rnPwYDfAk2t8tmuryFqvwAu
// 	...

// Decrypt to restore back to the original:
$success = $crypt->DecryptBd($jpgBytes);
if ($success != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

print $jpgBytes->getEncoded('base64_mime') . "\n";

// 	/9j/4AAQSkZJRgABAgEASABIAAD/7Q18UGhvdG9zaG9wIDMuMAA4QklNA+0AAAAAABAASAAAAAEA
// 	AQBIAAAAAQABOEJJTQPzAAAAAAAIAAAAAAAAAAE4QklNBAoAAAAAAAEAADhCSU0nEAAAAAAACgAB
// 	AAAAAAAAAAI4QklNA/UAAAAAAEgAL2ZmAAEAbGZmAAYAAAAAAAEAL2ZmAAEAoZmaAAYAAAAAAAEA
// 	MgAAAAEAWgAAAAYAAAAAAAEANQAAAAEALQAAAAYAAAAAAAE4QklNBBQAAAAAAAQAAAABOEJJTQQM
// 	...

// ----------------------------------------------------------------------------------
// To do chacha20 encryption, just change the settings:

$crypt->put_CryptAlgorithm('chacha20');
$crypt->put_KeyLength(256);
// The initial count is the initial block counter for the chacha20 algorithm.
// It can be any integer, but must be set to the same when decrypting.
$crypt->put_InitialCount(22);

$success = $crypt->EncryptBd($jpgBytes);
// jpgBytes now contains chacha20 encrypted bytes.

$success = $crypt->DecryptBd($jpgBytes);
// jpgBytes is now restored back to the original unencrypted by bytes.

// Save the bytes to a file..
$success = $jpgBytes->WriteFile('qa_output/starfish.jpg');

print 'Success.' . "\n";

?>