Perl Requires Chilkat v9.5.0.66+

JWE using AES Key Wrap and AES_128_CBC_HMAC_SHA_256

See more JSON Web Encryption (JWE) Examples

This example duplicates the example A.3 in RFC 7516 for JSON Web Encryption (JWE). Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

my $plaintext = 'Live long and prosper.';

my $jwe = Chilkat2::Jwe->new;

# First build the JWE Protected Header: {"alg":"A128KW","enc":"A128CBC-HS256"}
my $jweProtHdr = Chilkat2::JsonObject->new;
$jweProtHdr->AppendString('alg', 'A128KW');
$jweProtHdr->AppendString('enc', 'A128CBC-HS256');
$jwe->SetProtectedHeader($jweProtHdr);

print 'JWE Protected Header: ', $jweProtHdr->Emit(), "\n";
print "--\n";

# The example A.3 in RFC 7516 uses the following 128-bit AES key,
# specified in JWK (JSON Web Key) format:
#      {"kty":"oct",
#       "k":"GawgguFyGrWKav7AX4VKUg"
#      }
# This is just a way of saying: The key type ("kty") is
# a bunch of octets ("k") in base64url encoding.
# We can simply set the AES wrapping key like this:
my $aesWrappingKey = 'GawgguFyGrWKav7AX4VKUg';
$jwe->SetWrappingKey(0, $aesWrappingKey, 'base64url');

# Encrypt and return the JWE:
my $strJwe = $jwe->Encrypt($plaintext, 'utf-8');
if (!$jwe->LastMethodSuccess) {
    print $jwe->LastErrorText, "\n";
    exit;
}

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

# Decrypt the JWE that was just produced.
# 1) Load the JWE.
# 2) Set the AES wrapping key.
# 3) Decrypt.
my $jwe2 = Chilkat2::Jwe->new;
my $success = $jwe2->LoadJwe($strJwe);
if (!$success) {
    print $jwe2->LastErrorText, "\n";
    exit;
}

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

# Decrypt.
my $originalPlaintext = $jwe2->Decrypt(0, 'utf-8');
if (!$jwe2->LastMethodSuccess) {
    print $jwe2->LastErrorText, "\n";
    exit;
}

print "original text: \n";
print $originalPlaintext, "\n";

# ---------------------------------------------------------------------------------
# It should also be possible to decrypt the JWE as shown in RFC 7516, Appendix A.3.7
# because it was produced using the same AES Wrap key.

my $sbJwe = Chilkat2::StringBuilder->new;
$sbJwe->Append('eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.');
$sbJwe->Append('6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ.');
$sbJwe->Append('AxY8DCtDaGlsbGljb3RoZQ.');
$sbJwe->Append('KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.');
$sbJwe->Append('U0m_YmjN04DJvceFICbCVQ');

$success = $jwe2->LoadJweSb($sbJwe);
if (!$success) {
    print $jwe2->LastErrorText, "\n";
    exit;
}

$jwe2->SetWrappingKey(0, $aesWrappingKey, 'base64url');

# Decrypt.
$originalPlaintext = $jwe2->Decrypt(0, 'utf-8');
if (!$jwe2->LastMethodSuccess) {
    print $jwe2->LastErrorText, "\n";
    exit;
}

print $originalPlaintext, "\n";