[](https://github.com/durch/rust-goauth/blob/master/LICENSE)
[](https://crates.io/crates/goauth)
[](https://crates.io/crates/goauth)
## rust-goauth [[docs](https://docs.rs/goauth)]
Crate for using [OAuth 2.0 with Server to Server Applications](https://developers.google.com/identity/protocols/OAuth2ServiceAccount) for Google Cloud Engine, with tentative support for all supported [Scopes](https://durch.github.io/rust-goauth/goauth/scopes/enum.Scope.html). Supports sync or async requests via Futures.
Provides a serialisable [Token](https://durch.github.io/rust-goauth/goauth/auth/struct.Token.html) struct for use in other applications that require authenticated interactions with Google Cloud.
### Usage
```rust,no_run
#[macro_use]
extern crate log;
use goauth::auth::JwtClaims;
use goauth::scopes::Scope;
use goauth::{get_token, get_token_blocking, GoErr};
use goauth::credentials::Credentials;
use goauth::fetcher::TokenFetcher;
use smpl_jwt::{RSAKey, Jwt};
use time::Duration;
fn main() -> Result<(), GoErr>{
let token_url = "https://www.googleapis.com/oauth2/v4/token";
let iss = "<some-iss>"; // https://developers.google.com/identity/protocols/OAuth2ServiceAccount
let credentials = Credentials::from_file("dummy_credentials_file_for_tests.json").unwrap();
let claims = JwtClaims::new(String::from(iss),
&Scope::DevStorageReadWrite,
String::from(token_url),
None, None);
let jwt = Jwt::new(claims, credentials.rsa_key().unwrap(), None);
// Use async
let token = async {
match get_token(&jwt, &credentials).await {
Ok(token) => token,
Err(e) => panic!(e)
}
};
// Or sync
let token = get_token_blocking(&jwt, &credentials)?;
// Token provides `access_token` method that outputs a value that should be placed in the Authorization header
// Or use the TokenFetcher abstraction which will automatically refresh tokens
let fetcher = TokenFetcher::new(jwt, credentials, Duration::new(1, 0));
let token = async {
match fetcher.fetch_token().await {
Ok(token) => token,
Err(e) => panic!(e)
}
};
// Now a couple seconds later we want the token again - the initial token is cached so it will re-use
// the same token, saving a network trip to fetch another token
let new_token = async {
match fetcher.fetch_token().await {
Ok(token) => token,
Err(e) => panic!(e)
}
};
assert_eq!(token, new_token);
// Now say the token has expired or is close to expiring ("close" defined by the configurable
// `refresh_buffer` parameter) at this point "later in the program." The next call to
// `fetch_token` will notice this and automatically fetch a new token, cache it, and return it.
let new_token = async {
match fetcher.fetch_token().await {
Ok(token) => token,
Err(e) => panic!(e)
}
};
assert_ne!(token, new_token);
Ok(())
}
```