Java

Compute JWK Thumbprint for RSA and EC Public Keys

See more ECC Examples

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.

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.PublicKey;
import com.chilkatsoft.chilkat2.StringBuilder;

public class ChilkatExample {

    public static void main(String[] args) {
        PublicKey pubKey = new 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...

        StringBuilder sb = new 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..
        try {
            pubKey.loadFromString(sb.getAsString());
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Get the JWK thumbprint (using SHA256)
        System.out.println("JWK thumbprint: " + pubKey.getJwkThumbprint("SHA256"));

        // 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("}");

        try {
            pubKey.loadFromString(sb.getAsString());
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Get the JWK thumbprint (using SHA256)
        System.out.println("JWK thumbprint: " + pubKey.getJwkThumbprint("SHA256"));

        // Output:
        // JWK thumbprint: 8fm8079s3nu4FLV_7dVJoJ69A8XCXn7Za2mtaWCnxR4
    }
}