(Perl) Verify JWT Using an ECC Public Key (ES256, ES384, ES512)

Demonstrates how to verify a JWT that was signed using an ECC private key.

This example verifies the ECC signature. It also does the following:

• Checks to see if the time constraints ("nbf" and "exp") are valid.
• Recovers the original JOSE header.
• Recovers the original claims JSON.

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

use chilkat();

# Demonstrates how to verify an JWT using an ECC public key.

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

$pubKey = chilkat::CkPublicKey->new();
$success = $pubKey->LoadFromFile("qa_data/pem/ecc_public.pem");

$jwt = chilkat::CkJwt->new();

$token = "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDg1NzA4NzkyLCJuYmYiOjE0ODU3MDg3OTIsImV4cCI6MTQ4NTcxMjM5Mn0.wqsuyJpxJ073ox-lOiLFqG1lQocXe4hGf2XGZJRrO3qn0UusxI_bu3Gzky8gBsH4sA4u9TWZn5M-1wYMMIJk6Q";

# First verify the signature.
$sigVerified = $jwt->VerifyJwtPk($token,$pubKey);
print "verified: " . $sigVerified . "\r\n";

# Let's see if the time constraints, if any, are valid.
# The above JWT was created on the afternoon of 16-May-2016, with an expiration of 1 hour.
# If the current system time is before the "nbf" time, or after the "exp" time,
# then IsTimeValid will return false/0.
# Also, we'll allow a leeway of 60 seconds to account for any clock skew.
# Note: If the token has no "nbf" or "exp" claim fields, then IsTimeValid is always true.
$leeway = 60;
$bTimeValid = $jwt->IsTimeValid($token,$leeway);
print "time constraints valid: " . $bTimeValid . "\r\n";

# Now let's recover the original claims JSON (the payload).
$payload = $jwt->getPayload($token);
# The payload will likely be in compact form:
print $payload . "\r\n";

# We can format for human viewing by loading it into Chilkat's JSON object
# and emit.
$json = chilkat::CkJsonObject->new();
$success = $json->Load($payload);
$json->put_EmitCompact(0);
print $json->emit() . "\r\n";

# We can recover the original JOSE header in the same way:
$joseHeader = $jwt->getHeader($token);
# The payload will likely be in compact form:
print $joseHeader . "\r\n";

# We can format for human viewing by loading it into Chilkat's JSON object
# and emit.
$success = $json->Load($joseHeader);
$json->put_EmitCompact(0);
print $json->emit() . "\r\n";