(Perl) Streaming Encryption

Encrypt and decrypt using a stream.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

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

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

# 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 = chilkat::CkStream->new();

# We'll save the encrypted output in eStrings to demonstrate streaming decryption next.
$eStrings = chilkat::CkStringArray->new();

# Start a background task that will encrypt a stream.
# task is a Task
$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() == 1) {
        $cipherText = $stream->readBytesENC("hex");
        print $cipherText . "\r\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() != 1)) {
    $task->SleepMs(20);
}

# Get any remaining data available from the stream.
if ($stream->get_DataAvailable() == 1) {
    $cipherText = $stream->readBytesENC("hex");
    print $cipherText . "\r\n";
    $success = $eStrings->Append($cipherText);
}

if ($task->get_TaskSuccess() != 1) {
    print "async encryption failed:" . "\r\n";
    print $task->resultErrorText() . "\r\n";
    $success = 0;
}

print "-- encrypt finished --" . "\r\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 Task
$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() == 1) {
        $plainText = $stream->readString();
        print $plainText . "\r\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() != 1)) {
    $task->SleepMs(20);
}

# Get any remaining data available from the stream.
if ($stream->get_DataAvailable() == 1) {
    $plainText = $stream->readString();
    print $plainText . "\r\n";
}

if ($task->get_TaskSuccess() != 1) {
    print "async decryption failed:" . "\r\n";
    print $task->resultErrorText() . "\r\n";
    $success = 0;
}

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