Perl

JWE using "dir" Direct use of Shared Symmetric Key

See more JSON Web Encryption (JWE) Examples

Demonstrates how to create a JWE using the "dir" alg -- which is to directly use a shared symmetric key.

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

Perl

use chilkat();

$success = 0;

# 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.

$plaintext = "Live long and prosper.";

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

# First build the JWE Protected Header..
$jweProtHdr = chilkat::CkJsonObject->new();
$jweProtHdr->AppendString("alg","dir");
$jweProtHdr->AppendString("enc","A128GCM");

# Don't forget to actually provide the protected header to the JWE object:
$jwe->SetProtectedHeader($jweProtHdr);

# The JWE is to use 128-bit AES GCM encryption as specified by the "enc" parameter.
# Given that the "alg" = "dir", we are to directly specify the AES GCM key.
# (It is assumed that the decrypting side also has knowledge of the direct key to be used..)

# Our key will be these 16 hex bytes: 000102030405060708090A0B0C0D0E0F

# The SetWrappingKey method is also used for "dir" direct keys.
# However, if there are multiple recipients, they must all share the same CEK (Content Encryption Key),
# which is specified by calling SetWrappingKey with an index of 0.

$recipientIndex = 0;
$jwe->SetWrappingKey($recipientIndex,"000102030405060708090A0B0C0D0E0F","hex");

# Encrypt and return the JWE:
$strJwe = $jwe->encrypt($plaintext,"utf-8");
if ($jwe->get_LastMethodSuccess() != 1) {
    print $jwe->lastErrorText() . "\r\n";
    exit;
}

# Show the JWE we just created:
print $strJwe . "\r\n";

# Decrypt the JWE.
$jwe2 = chilkat::CkJwe->new();
$success = $jwe2->LoadJwe($strJwe);
if ($success != 1) {
    print $jwe2->lastErrorText() . "\r\n";
    exit;
}

$jwe2->SetWrappingKey(0,"000102030405060708090A0B0C0D0E0F","hex");

# Decrypt.
$originalPlaintext = $jwe2->decrypt(0,"utf-8");
if ($jwe2->get_LastMethodSuccess() != 1) {
    print $jwe2->lastErrorText() . "\r\n";
    exit;
}

print "original text: " . "\r\n";
print $originalPlaintext . "\r\n";

# Sample output:
# eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4R0NNIn0..20HX5Huc7f1nQC4pBUtiCQ.axFZIxtZy5j0ifJQUzGXLKIpsBuxJA.eBrOC-NrsreN6JeGuOPk1g
# original text: 
# Live long and prosper.