PHP Extension

JWE with DEFLATE Compression

See more JSON Web Encryption (JWE) Examples

Demonstrates how to DEFLATE ("zip") compress the JWE payload prior to encryption.

Note: This example requires Chilkat v9.5.0.66 or greater.

PHP Extension

<?php

include("chilkat.php");

$success = false;

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

// Note: This example requires Chilkat v9.5.0.66 or greater.

// Create some plaintext to be encrypted.
// This example will demonstrate with and without DEFLATE (zip) compression.
$sbPlainText = new CkStringBuilder();
$bCrLf = true;
$line = 'Live long and prosper.';
$sbPlainText->AppendLine($line,$bCrLf);
$sbPlainText->AppendLine($line,$bCrLf);
$sbPlainText->AppendLine($line,$bCrLf);
$sbPlainText->AppendLine($line,$bCrLf);

// The text to be encrypted:
print $sbPlainText->getAsString() . "\n";

$jwe = new CkJwe();

// Build the JWE Protected Header: {"alg":"A128KW","enc":"A128CBC-HS256","zip":"DEF"}
// The "zip":"DEF" parameter indicates that the plaintext payload should
// be compressed prior to encryption.
$jweProtHdr = new CkJsonObject();
$jweProtHdr->AppendString('alg','A128KW');
$jweProtHdr->AppendString('enc','A128CBC-HS256');
$jweProtHdr->AppendString('zip','DEF');
$jwe->SetProtectedHeader($jweProtHdr);

// Set the AES key wrap key:
$aesWrappingKey = 'GawgguFyGrWKav7AX4VKUg';
$jwe->SetWrappingKey(0,$aesWrappingKey,'base64url');

// Encrypt and return the JWE in sbJweCompressed:
$sbJweCompressed = new CkStringBuilder();
$success = $jwe->EncryptSb($sbPlainText,'utf-8',$sbJweCompressed);
if ($success != true) {
    print $jwe->lastErrorText() . "\n";
    exit;
}

// Show the compressed JWE:
print $sbJweCompressed->getAsString() . "\n";
print 'size of compressed JWE: ' . $sbJweCompressed->get_Length() . "\n";

// Now create a JWE without compression.
$jweProtHdr->Delete('zip');
// Make sure to update the shared protected header:
$jwe->SetProtectedHeader($jweProtHdr);

$sbJweUncompressed = new CkStringBuilder();
$success = $jwe->EncryptSb($sbPlainText,'utf-8',$sbJweUncompressed);
if ($success != true) {
    print $jwe->lastErrorText() . "\n";
    exit;
}

// Show the uncompressed JWE:
print $sbJweUncompressed->getAsString() . "\n";
print 'size of uncompressed JWE: ' . $sbJweUncompressed->get_Length() . "\n";

// Decrypting is the same whether compression is used or not.
// The "zip" header in the JWE indicates that the payload should be 
// automatically decompressed (inflated) after decrypting.
$jwe2 = new CkJwe();
$success = $jwe2->LoadJweSb($sbJweCompressed);
if ($success != true) {
    print $jwe2->lastErrorText() . "\n";
    exit;
}

// Set the AES wrap key.
$jwe2->SetWrappingKey(0,$aesWrappingKey,'base64url');

// Decrypt (also automatically decompresses).
$sbOriginalText = new CkStringBuilder();
$success = $jwe2->DecryptSb(0,'utf-8',$sbOriginalText);
if ($success != true) {
    print $jwe2->lastErrorText() . "\n";
    exit;
}

print 'original text from compressed JWE: ' . "\n";
print $sbOriginalText->getAsString() . "\n";

// -----------------------------------------------------------
// Do the same with the uncompressed JWE

$success = $jwe2->LoadJweSb($sbJweUncompressed);
if ($success != true) {
    print $jwe2->lastErrorText() . "\n";
    exit;
}

// Set the AES wrap key.
$jwe2->SetWrappingKey(0,$aesWrappingKey,'base64url');

// Decrypt.
$sbOriginalText->Clear();
$success = $jwe2->DecryptSb(0,'utf-8',$sbOriginalText);
if ($success != true) {
    print $jwe2->lastErrorText() . "\n";
    exit;
}

print 'original text from uncompressed JWE: ' . "\n";
print $sbOriginalText->getAsString() . "\n";

// ------------------------------------------------
// The output of this example is:
// (Note: Your output data will be different because the content encryption key is randomly generated.)

// eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2IiwiemlwIjoiREVGIn0.xuW-pEAIdEUFnk10m8ocursvktO8Of9ByCCAt6LgKkkOtCWCUn1kQw.zpGj-9WVni3cQxyOuZbcGA.0hzP1myua3oYpUHwCIY_3edBUREbUpLaX6wYuJduOdI.Ppc6aEO3y3B8BJ1FKMPjlA
// size of compressed JWE: 212
// eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.N4KeyC7nnSFkieJOyE24_zKeuV_m7v5UKoJb1TgV4Yc_r2RzUPNvyA.6AEdyXSCKx-iMmUJyypSLg.QpixfyrwhGpmwUDp623viik4smPav7vwPLiC2r-V-jwnSfEH3mxWu6DbrIz3mixaqATwynmEBzVPxvS9jTXpSAGCnniib4_0WoPl3r_wF5tlsKOEe--jpNso-DKd1Tp8jJxj3JkFWt3IRnUUKGj17g.sBfDwFc5fzpaI-UW8-SW4g
// size of uncompressed JWE: 303
// original text from compressed JWE: 
// Live long and prosper.
// Live long and prosper.
// Live long and prosper.
// Live long and prosper.
// 
// original text from uncompressed JWE: 
// Live long and prosper.
// Live long and prosper.
// Live long and prosper.
// Live long and prosper.
// 

?>