(PHP ActiveX) Compute JWK Thumbprint for RSA and EC Public Keys

Demonstrates how to compute a JSON Web Key thumbprint for a public key (RSA or ECC).

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows Note: The php_com_dotnet.dll may need to be enabled inside of php.ini.

<?php

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.PublicKey')
$pubKey = new COM("Chilkat.PublicKey");

// A public key can be loaded from any format (binary DER, PEM, etc.)
// This example will load the public keys from JWK format, 
// and will then compute the JWK thumbprint.

// First do it for an RSA public key...

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.StringBuilder')
$sb = new COM("Chilkat.StringBuilder");
$sb->Append('{');
$sb->Append('\'kty\': \'RSA\',');
$sb->Append('\'n\': \'0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78LhWx4cbbfAAt');
$sb->Append('VT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCiFV4n3oknjhMstn6');
$sb->Append('4tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65YGjQR0_FD');
$sb->Append('W2QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n9');
$sb->Append('1CbOpbISD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINH');
$sb->Append('aQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw\',');
$sb->Append('\'e\': \'AQAB\',');
$sb->Append('\'alg\': \'RS256\',');
$sb->Append('\'kid\': \'2011-04-29\'');
$sb->Append('}');

// The JWK format is automatically detected..
$success = $pubKey->LoadFromString($sb->getAsString());
if ($success != 1) {
    print $pubKey->LastErrorText . "\n";
    exit;
}

// Get the JWK thumbprint (using SHA256)
print 'JWK thumbprint: ' . $pubKey->getJwkThumbprint('SHA256') . "\n";

// Output:
// JWK thumbprint: NzbLsXh8uDCcd-6MNwXF4W_7noWXFZAfHkxZsRGC9Xs

// --------------------------------------------------------------
// Now let's do an EC public key:
$sb->Clear();
$sb->Append('{ ');
$sb->Append('  \'kty\': \'EC\',');
$sb->Append('  \'crv\': \'P-256\',');
$sb->Append('  \'x\': \'tDeeYABgKEAbWicYPCEEI8sP4SRIhHKcHDW7VqrB4LA\',');
$sb->Append('  \'y\': \'J08HOoIZ0rX2Me3bNFZUltfxIk1Hrc8FsLu8VaSxsMI\'');
$sb->Append('}');

$success = $pubKey->LoadFromString($sb->getAsString());
if ($success != 1) {
    print $pubKey->LastErrorText . "\n";
    exit;
}

// Get the JWK thumbprint (using SHA256)
print 'JWK thumbprint: ' . $pubKey->getJwkThumbprint('SHA256') . "\n";

// Output:
// JWK thumbprint: 8fm8079s3nu4FLV_7dVJoJ69A8XCXn7Za2mtaWCnxR4

?>