Rust

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.

Rust

let pub_key = chilkat::PublicKey::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...

let sb = chilkat::StringBuilder::new();
let _ = sb.append("{");
let _ = sb.append("\"kty\": \"RSA\",");
let _ = sb.append("\"n\": \"0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78LhWx4cbbfAAt");
let _ = sb.append("VT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCiFV4n3oknjhMstn6");
let _ = sb.append("4tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65YGjQR0_FD");
let _ = sb.append("W2QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n9");
let _ = sb.append("1CbOpbISD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINH");
let _ = sb.append("aQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw\",");
let _ = sb.append("\"e\": \"AQAB\",");
let _ = sb.append("\"alg\": \"RS256\",");
let _ = sb.append("\"kid\": \"2011-04-29\"");
let _ = sb.append("}");

// The JWK format is automatically detected..
if pub_key.load_from_string(&sb.get_as_string().unwrap_or_default()).is_err() {
    println!("{}", pub_key.last_error_text());
    return;
}

// Get the JWK thumbprint (using SHA256)
println!("JWK thumbprint: {}", pub_key.get_jwk_thumbprint("SHA256").unwrap_or_default());

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

// --------------------------------------------------------------
// Now let's do an EC public key:
sb.clear();
let _ = sb.append("{ ");
let _ = sb.append("  \"kty\": \"EC\",");
let _ = sb.append("  \"crv\": \"P-256\",");
let _ = sb.append("  \"x\": \"tDeeYABgKEAbWicYPCEEI8sP4SRIhHKcHDW7VqrB4LA\",");
let _ = sb.append("  \"y\": \"J08HOoIZ0rX2Me3bNFZUltfxIk1Hrc8FsLu8VaSxsMI\"");
let _ = sb.append("}");

if pub_key.load_from_string(&sb.get_as_string().unwrap_or_default()).is_err() {
    println!("{}", pub_key.last_error_text());
    return;
}

// Get the JWK thumbprint (using SHA256)
println!("JWK thumbprint: {}", pub_key.get_jwk_thumbprint("SHA256").unwrap_or_default());

// Output:
// JWK thumbprint: 8fm8079s3nu4FLV_7dVJoJ69A8XCXn7Za2mtaWCnxR4