Rust Requires Chilkat v11.0.0+

Validate a JWS Using ECDSA P-256 SHA-256

See more JSON Web Signatures (JWS) Examples

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.

// This example takes a JSON signature in compact serialization format,
// and uses an ECDSA public key to validate and recover the protected header and payload.

// We only need a public key for signature validation.  This is the ECDSA public key
// that is used:

//      {"kty":"EC", 
//       "crv":"P-256", 
//       "x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU", 
//       "y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0" 
//      } 

let sb_pub_key = chilkat::StringBuilder::new();
let _ = sb_pub_key.append("{\"kty\":\"EC\",");
let _ = sb_pub_key.append("\"crv\":\"P-256\",");
let _ = sb_pub_key.append("\"x\":\"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU\",");
let _ = sb_pub_key.append("\"y\":\"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0\"");
let _ = sb_pub_key.append("}");

let pub_key = chilkat::PublicKey::new();
if pub_key.load_from_string(&sb_pub_key.get_as_string().unwrap_or_default()).is_err() {
    println!("{}", pub_key.last_error_text());
    return;
}

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

// Set the ECC public key:
let signature_index = 0;
let _ = jws.set_public_key(signature_index, &pub_key);

// Load the JWS.
let sb_jws = chilkat::StringBuilder::new();
let _ = sb_jws.append("eyJhbGciOiJFUzI1NiJ9");
let _ = sb_jws.append(".");
let _ = sb_jws.append("eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt");
let _ = sb_jws.append("cGxlLmNvbS9pc19yb290Ijp0cnVlfQ");
let _ = sb_jws.append(".");
let _ = sb_jws.append("DtEhU3ljbEg8L38VWAfUAqOyKAM6-Xx-F4GawxaepmXFCgfTjDxw5djxLa8ISlSA");
let _ = sb_jws.append("pmWQxfKTUJqPP3-Kg6NU1Q");

if jws.load_jws_sb(&sb_jws).is_err() {
    println!("{}", jws.last_error_text());
    return;
}

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

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

// Examine the protected header:

let jose_header = chilkat::JsonObject::new();
if jws.get_protected_h(signature_index, &jose_header).is_err() {
    println!("{}", jws.last_error_text());
    return;
}

jose_header.set_emit_compact(false);

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

// Output:

// 	Signature validated.
// 	--
// 	Recovered content:
// 	{"iss":"joe",
// 	 "exp":1300819380,
// 	 "http://example.com/is_root":true}
// 	--
// 	Protected (JOSE) header:
// 	{ 
// 	  "alg": "ES256"
// 	}