Rust Requires Chilkat v11.0.0+

Create a JWS Using ECDSA P-256 SHA-256

See more JSON Web Signatures (JWS) Examples

Creates and validates a JSON Web Signature (JWS) that uses ECDSA P-256 SHA-256 Rust

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

// Use the following ECC key loaded from JWK format.
let sb_jwk = chilkat::StringBuilder::new();
let _ = sb_jwk.append("{\"kty\":\"EC\",");
let _ = sb_jwk.append("\"crv\":\"P-256\",");
let _ = sb_jwk.append("\"x\":\"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU\",");
let _ = sb_jwk.append("\"y\":\"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0\",");
let _ = sb_jwk.append("\"d\":\"jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI\"");
let _ = sb_jwk.append("}");

let ecc_key = chilkat::PrivateKey::new();
// Note: This example loads the ECDSA key from JWK format.  Any format can be loaded
// into the private key object. (See the online reference documentation..)
if ecc_key.load_jwk(&sb_jwk.get_as_string().unwrap_or_default()).is_err() {
    println!("{}", ecc_key.last_error_text());
    return;
}

// Create the JWS Protected Header
let jws_prot_hdr = chilkat::JsonObject::new();
let _ = jws_prot_hdr.append_string("alg", "ES256");

let jws = chilkat::Jws::new();

// Set the protected header:
let mut signature_index = 0;
let _ = jws.set_protected_header(signature_index, &jws_prot_hdr);

// Set the ECC key:
let _ = jws.set_private_key(signature_index, &ecc_key);

// Set the payload.
let b_include_bom = false;
let payload_str = "In our village, folks say God crumbles up the old moon into stars.".to_string();
let _ = jws.set_payload(&payload_str, "utf-8", b_include_bom);

// Create the JWS
// By default, the compact serialization is used.
let Ok(jws_compact) = jws.create_jws() else {
    println!("{}", jws.last_error_text());
    return;
};

println!("JWS: {}", jws_compact);

// Note: ECC signatures use random values, so the output will be different each time a signature is produced.
// sample output:
// JWS: eyJhbGciOiJFUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.J6EGTNkeuEjehHHBu0SOKzifm8r35wbx49A5964pxzB7gannyZZPMkK7vmlaPJ-K8Xmm8cZsQySAPC12Xd8avw

// Now load the JWS, validate, and recover the original text.
let jws2 = chilkat::Jws::new();

// Load the JWS.
let _ = jws2.load_jws(&jws_compact).is_ok();

let ecc_pub_key = chilkat::PublicKey::new();
let _ = ecc_key.to_public_key(&ecc_pub_key);

// Set the ECC public key used for validation.
signature_index = 0;
let _ = jws2.set_public_key(signature_index, &ecc_pub_key);

// Validate the 1st (and only) signature at index 0..
let v = jws2.validate(signature_index);
if v < 0 {
    // Perhaps Chilkat was not unlocked or the trial expired..
    println!("Method call failed for some other reason.");
    println!("{}", jws2.last_error_text());
    return;
}

if v == 0 {
    println!("Invalid signature.  The ECC key was incorrect, the JWS was invalid, or both.");
    return;
}

// If we get here, the signature was validated..
println!("Signature validated.");

// Recover the original content:
println!("{}", jws2.get_payload("utf-8").unwrap_or_default());

// Examine the protected header:
let jose_header = chilkat::JsonObject::new();
let _ = jws2.get_protected_h(signature_index, &jose_header);
jose_header.set_emit_compact(false);

println!("Protected (JOSE) header:");
println!("{}", jose_header.emit().unwrap_or_default());

// Output:

// Signature validated.
// In our village, folks say God crumbles up the old moon into stars.
// Protected (JOSE) header:
// { 
//   "alg": "ES256"
// }