(Perl) 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 Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

$pubKey = chilkat::CkPublicKey->new();

# 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...

$sb = chilkat::CkStringBuilder->new();
$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() . "\r\n";
    exit;
}

# Get the JWK thumbprint (using SHA256)
print "JWK thumbprint: " . $pubKey->getJwkThumbprint("SHA256") . "\r\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() . "\r\n";
    exit;
}

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

# Output:
# JWK thumbprint: 8fm8079s3nu4FLV_7dVJoJ69A8XCXn7Za2mtaWCnxR4