(PHP Extension) Streaming Encryption

Encrypt and decrypt using a stream.

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.

$crypt = new CkCrypt2();

// Setup encryption using the chacha20 algorithm...
$crypt->put_CryptAlgorithm('chacha20');
$crypt->put_KeyLength(256);
$crypt->put_EncodingMode('hex');
$ivHex = '000000000000000000000002';
$crypt->SetEncodedIV($ivHex,'hex');
$crypt->put_InitialCount(42);
$keyHex = '1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0';
$crypt->SetEncodedKey($keyHex,'hex');

$plainText = 'The quick brown fox jumped over the lazy dog.\r\n';

$stream = new CkStream();

// We'll save the encrypted output in eStrings to demonstrate streaming decryption next.
$eStrings = new CkStringArray();

// Start a background task that will encrypt a stream.
// task is a CkTask
$task = $crypt->EncryptStreamAsync($stream);
$success = $task->Run();

// Write plainText to the stream, and read chacha20 encrypted text..

for ($i = 1; $i <= 10; $i++) {
    // Note: An encryption algorithm's block size will cause buffering,
    // and therefore not every loop iteration will produce output.
    $success = $stream->WriteString($plainText);
    if ($stream->get_DataAvailable() == true) {
        $cipherText = $stream->readBytesENC('hex');
        print $cipherText . "\n";
        $success = $eStrings->Append($cipherText);
    }

}

// Tell the background task that the stream has ended.
$success = $stream->WriteClose();

// Let's make sure the background task finished.
// It should already be the case that the task is finished.
while (($task->get_Finished() != true)) {
    $task->SleepMs(20);
}

// Get any remaining data available from the stream.
if ($stream->get_DataAvailable() == true) {
    $cipherText = $stream->readBytesENC('hex');
    print $cipherText . "\n";
    $success = $eStrings->Append($cipherText);
}

if ($task->get_TaskSuccess() != true) {
    print 'async encryption failed:' . "\n";
    print $task->resultErrorText() . "\n";
    $success = false;
}

print '-- encrypt finished --' . "\n";

// Now decrypt to return the original.

// Reset the stream object so it can be used again.
$stream->Reset();

// Start a background task that will decrypt a stream.
// task is a CkTask
$task = $crypt->DecryptStreamAsync($stream);
$success = $task->Run();

$n = $eStrings->get_Count();
for ($i = 0; $i <= $n - 1; $i++) {
    $success = $stream->WriteBytesENC($eStrings->getString($i),'hex');
    if ($stream->get_DataAvailable() == true) {
        $plainText = $stream->readString();
        print $plainText . "\n";
    }

}

// Tell the background task that the stream has ended.
$success = $stream->WriteClose();

// Let's make sure the background task finished.
// It should already be the case that the task is finished.
while (($task->get_Finished() != true)) {
    $task->SleepMs(20);
}

// Get any remaining data available from the stream.
if ($stream->get_DataAvailable() == true) {
    $plainText = $stream->readString();
    print $plainText . "\n";
}

if ($task->get_TaskSuccess() != true) {
    print 'async decryption failed:' . "\n";
    print $task->resultErrorText() . "\n";
    $success = false;
}

print '-- decrypt finished --' . "\n";

?>