(Perl) JWE with Binary Data

Demonstrates how to create a JWE that contains a binary payload (such as a JPG image).

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

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

use chilkat();

# 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.

# Load a JPG file that will be the JWE payload.
$jpgBytes = chilkat::CkBinData->new();
$success = $jpgBytes->LoadFile("qa_data/jpg/starfish.jpg");
# Make sure your app checks the success/failure of the call to LoadFile..
print "Original JPG size = " . $jpgBytes->get_NumBytes() . "\r\n";

$jwe = chilkat::CkJwe->new();

$jweProtHdr = chilkat::CkJsonObject->new();
$jweProtHdr->AppendString("alg","A128KW");
$jweProtHdr->AppendString("enc","A128CBC-HS256");
$jwe->SetProtectedHeader($jweProtHdr);

$aesWrappingKey = "GawgguFyGrWKav7AX4VKUg";
$jwe->SetWrappingKey(0,$aesWrappingKey,"base64url");

# Encrypt and return the JWE in sbJwe:
$sbJwe = chilkat::CkStringBuilder->new();
$success = $jwe->EncryptBd($jpgBytes,$sbJwe);
if ($success != 1) {
    print $jwe->lastErrorText() . "\r\n";
    exit;
}

# Show the JWE:
print $sbJwe->getAsString() . "\r\n";
print "size of JWE: " . $sbJwe->get_Length() . "\r\n";

# ---------------------------------------------------------
# Decrypt to get the original JPG file..

$jwe2 = chilkat::CkJwe->new();
$success = $jwe2->LoadJweSb($sbJwe);
if ($success != 1) {
    print $jwe2->lastErrorText() . "\r\n";
    exit;
}

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

# Decrypt.
$jpgOriginal = chilkat::CkBinData->new();
$success = $jwe2->DecryptBd(0,$jpgOriginal);
if ($success != 1) {
    print $jwe2->lastErrorText() . "\r\n";
    exit;
}

print "Decrypted JPG size = " . $jpgOriginal->get_NumBytes() . "\r\n";

# Save the decrypted JPG to a file.
$success = $jpgOriginal->WriteFile("qa_output/jwe_decrypted_starfish.jpg");

print "success = " . $success . "\r\n";

# The output of this program, when tested, was:
# Original JPG size = 6229
# eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.9YFz_wteV ... 7Et3hKhpxnKEXw
# size of JWE: 8473
# Decrypted JPG size = 6229
# success = True