(Perl) JWS Using HMAC SHA-256

Creates a JSON Web Signatures (JWS) using HMAC SHA-256.

Note: This example requires Chilkat v11.0.0 or greater.

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

use chilkat();

$success = 0;

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

# First create the JWS Protected Header
$jwsProtHdr = chilkat::CkJsonObject->new();
$jwsProtHdr->AppendString("typ","JWT");
$jwsProtHdr->AppendString("alg","HS256");
print "JWS Protected Header: " . $jwsProtHdr->emit() . "\r\n";

# Output:
# JWS Protected Header: {"typ":"JWT","alg":"HS256"}

$jws = chilkat::CkJws->new();

# Set the HMAC key:
$hmacKey = "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow";
$signatureIndex = 0;
$jws->SetMacKey($signatureIndex,$hmacKey,"base64url");

# Set the protected header:
$jws->SetProtectedHeader($signatureIndex,$jwsProtHdr);

# Set the payload.
$bIncludeBom = 0;
$payloadStr = "In our village, folks say God crumbles up the old moon into stars.";
$jws->SetPayload($payloadStr,"utf-8",$bIncludeBom);

# Create the JWS
# By default, the compact serialization is used.
$jwsCompact = $jws->createJws();
if ($jws->get_LastMethodSuccess() == 0) {
    print $jws->lastErrorText() . "\r\n";
    exit;
}

print "JWS: " . $jwsCompact . "\r\n";

# sample output:
# JWS: eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.bsYsi8HJ0N6OqGI1hKQ9QQRNPxxA5qMpcHLtOvXatk8

# Now load the JWS, validate, and recover the original text.
$jws2 = chilkat::CkJws->new();

# Load the JWS.
$success = $jws2->LoadJws($jwsCompact);

# Set the MAC key used for validation.
$signatureIndex = 0;
$jws2->SetMacKey($signatureIndex,$hmacKey,"base64url");

# Validate the 1st (and only) signature at index 0..
$v = $jws2->Validate($signatureIndex);
if ($v < 0) {
    # Perhaps Chilkat was not unlocked or the trial expired..
    print "Method call failed for some other reason." . "\r\n";
    print $jws2->lastErrorText() . "\r\n";
    exit;
}

if ($v == 0) {
    print "Invalid signature.  The MAC key was incorrect, the JWS was invalid, or both." . "\r\n";
    exit;
}

# If we get here, the signature was validated..
print "Signature validated." . "\r\n";

# Recover the original content:
print $jws2->getPayload("utf-8") . "\r\n";

# Examine the protected header:

$joseHeader = chilkat::CkJsonObject->new();
$success = $jws2->GetProtectedH($signatureIndex,$joseHeader);
if ($success == 0) {
    print $jws2->lastErrorText() . "\r\n";
    exit;
}

$joseHeader->put_EmitCompact(0);

print "Protected (JOSE) header:" . "\r\n";
print $joseHeader->emit() . "\r\n";

# Output:

# 	Signature validated.
# 	In our village, folks say God crumbles up the old moon into stars.
# 	Protected (JOSE) header:
# 	{ 
# 	  "typ": "JWT",
# 	  "alg": "HS256"
# 	}