Perl Requires Chilkat v11.0.0+

Create a JWS Using ECDSA P-256 SHA-256

See more JSON Web Signatures (JWS) Examples

Creates and validates a JSON Web Signature (JWS) that uses ECDSA P-256 SHA-256 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.

# Use the following ECC key loaded from JWK format.
my $sbJwk = Chilkat2::StringBuilder->new;
$sbJwk->Append('{"kty":"EC",');
$sbJwk->Append('"crv":"P-256",');
$sbJwk->Append('"x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU",');
$sbJwk->Append('"y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0",');
$sbJwk->Append('"d":"jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI"');
$sbJwk->Append('}');

my $eccKey = Chilkat2::PrivateKey->new;
# Note: This example loads the ECDSA key from JWK format.  Any format can be loaded
# into the private key object. (See the online reference documentation..)
my $success = $eccKey->LoadJwk($sbJwk->GetAsString());
if (!$success) {
    print $eccKey->LastErrorText, "\n";
    exit;
}

# Create the JWS Protected Header
my $jwsProtHdr = Chilkat2::JsonObject->new;
$jwsProtHdr->AppendString('alg', 'ES256');

my $jws = Chilkat2::Jws->new;

# Set the protected header:
my $signatureIndex = 0;
$jws->SetProtectedHeader($signatureIndex, $jwsProtHdr);

# Set the ECC key:
$jws->SetPrivateKey($signatureIndex, $eccKey);

# Set the payload.
my $bIncludeBom = 0;
my $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.
my $jwsCompact = $jws->CreateJws();
if (!$jws->LastMethodSuccess) {
    print $jws->LastErrorText, "\n";
    exit;
}

print 'JWS: ', $jwsCompact, "\n";

# Note: ECC signatures use random values, so the output will be different each time a signature is produced.
# sample output:
# JWS: eyJhbGciOiJFUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.J6EGTNkeuEjehHHBu0SOKzifm8r35wbx49A5964pxzB7gannyZZPMkK7vmlaPJ-K8Xmm8cZsQySAPC12Xd8avw

# Now load the JWS, validate, and recover the original text.
my $jws2 = Chilkat2::Jws->new;

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

my $eccPubKey = Chilkat2::PublicKey->new;
$eccKey->ToPublicKey($eccPubKey);

# Set the ECC public key used for validation.
$signatureIndex = 0;
$jws2->SetPublicKey($signatureIndex, $eccPubKey);

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

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

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

# Recover the original content:
print $jws2->GetPayload('utf-8'), "\n";

# Examine the protected header:
my $joseHeader = Chilkat2::JsonObject->new;
$jws2->GetProtectedH($signatureIndex, $joseHeader);
$joseHeader->EmitCompact(0);

print "Protected (JOSE) header:\n";
print $joseHeader->Emit(), "\n";

# Output:

# Signature validated.
# In our village, folks say God crumbles up the old moon into stars.
# Protected (JOSE) header:
# {
#   "alg": "ES256"
# }