Rust Requires Chilkat v11.0.0+

Validate a Google ID Token

See more OAuth2 Examples

Demonstrates how to verify the signature of a Google id token. Rust

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

let http = chilkat::Http::new();

// First get the public key we'll be needing..
let Ok(jwk_str) = http.quick_get_str("https://www.googleapis.com/oauth2/v3/certs") else {
    println!("{}", http.last_error_text());
    return;
};

// We have the following:

//     {
//       "keys": [
// 	{
// 	  "kid": "e8732db06287515556213b80acbcfd08cfb302a9",
// 	  "n": "4RIrO30287Wsq3gqXCMkUYMVAeI3H8...w2mbMNEBQ",
// 	  "kty": "RSA",
// 	  "e": "AQAB",
// 	  "alg": "RS256",
// 	  "use": "sig"
// 	},
// 	{
// 	  "kid": "8462a71da4f6d611fc0fecf0fc4ba9c37d65e6cd",
// 	  "e": "AQAB",
// 	  "n": "xT_ngLZNmT5GBtJZeTB...Ft4gK0eoFi0d3l8bcw",
// 	  "alg": "RS256",
// 	  "use": "sig",
// 	  "kty": "RSA"
// 	}
//       ]
//     }

let json = chilkat::JsonObject::new();
let _ = json.load(&jwk_str).is_ok();

// -------------------------------------------------

// Load the following..

//  {
//   "access_token": "ya29.a0...0f",
//   "expires_in": 3599,
//   "scope": "openid https://www.googleapis.com/auth/userinfo.email",
//   "token_type": "Bearer",
//   "id_token": "eyJhb...o5nQ"
// }

let json_token = chilkat::JsonObject::new();
if json_token.load_file("qa_data/tokens/google_sample_id_token.json").is_err() {
    println!("Failed to load the JSON file...");
    return;
}

// Get the id_token;
let sb_id_token = chilkat::StringBuilder::new();
let _ = sb_id_token.append(&json_token.string_of("id_token").unwrap_or_default()).is_ok();

// Get the signature in base64url format.
// The header + payload remains in sbIdToken.
let sig_b64_url = sb_id_token.get_after_final(".", true).unwrap_or_default();
let header_plus_payload = sb_id_token.get_as_string().unwrap_or_default();

println!("{}", sig_b64_url);
println!("{}", header_plus_payload);

// ---------------------------------------------

// Try validating with each cert's public key.
// Hopefully one will be the key that verifies.

let rsa = chilkat::Rsa::new();
rsa.set_encoding_mode("base64url");

let json_key = chilkat::JsonObject::new();
let pub_key = chilkat::PublicKey::new();

let num_keys = json.size_of_array("keys");
let mut i = 0;
while i < num_keys {
    json.set_i(i);

    let _ = json.object_of2("keys[i]", &json_key);

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

    println!("{}", i);
    println!("{}", pub_key.get_pem(true).unwrap_or_default());

    let _ = rsa.use_public_key(&pub_key).is_ok();

    let b_verified = rsa.verify_string_enc(&header_plus_payload, "sha256", &sig_b64_url).is_ok();
    println!("bVerified = {}", b_verified);

    i = i + 1;
}

// The output is:

// 0
// -----BEGIN RSA PUBLIC KEY-----
// MIIBCgKCAQEA4RIrO30287Wsq3gqXCMkUYMVAeI3H8LVE6IXR1krdFeGnZLiGUPw
// cbkeVpXf3lmJdsStOg+jijces2DZCfPyIBiQuLYfxxmAZE6ErJ0QJFg1stwli2Pz
// 9ncYhFoqi8pXr7kEzEJBTzX4thuw56ydbGsshSEznPXoerCJOc7UI2+n0wFCWQ4Y
// LHbh/PrWt4vdadyUUUW/QpQHXQLdD8q/Qwqdj0O9zlJE7R6Elw2E9EqnHyIGu1hm
// LxhqrTru1M18SUhONYbVskV/BCEdVKs//X96849HorWQDCAgVMWfGsdMVq55FAdJ
// 680N5UmQDRynIZ4+PeNGN4S9iw2mbMNEBQIDAQAB
// -----END RSA PUBLIC KEY-----
// 
// bVerified = True
// 1
// -----BEGIN RSA PUBLIC KEY-----
// MIIBCgKCAQEAxT/ngLZNmT5GBdkLtJZjNeTB+8B5yWgrq/e5eMZ1hrZhcmLK+dSn
// IkpOPV8/OekV67EnQ7I4II2rcNJnHGrGKZziXO3XN2gtUHE+mBJC99oULSbX/QwB
// Kz7gC/IBPq9EuxTt6Oq6fPkVQ9DbRIgWJSEGBF/KRaNl3kyAlIZfpY7XgHyJTTv8
// E7yAcYKPR+36gzdl+ps0sDLKzUuAtZNq8llK0u80z6AtAUIYwWdkEhM9upy6keKI
// TasIxcsO7M6kZPINUSbh6t5VAm8FuqRmxpgg+9c9/GQSGd89InVypoVzWLQ+wOGg
// 5G4H6JqIgtj0TRFt4gK0eoFi2U0d3l8bcwIDAQAB
// -----END RSA PUBLIC KEY-----
// 
// bVerified = False