README.md

OAuth2Authenticator

OAuth2 client for retrieving OAuth2 tokens and common token handling logic such as refresh and client credentials.

Nuget Package

Currently supported grant types

• Password
• Refresh Token
• Client Credentials

Setup

Initialize the client service in the application startup. 

public void ConfigureServices(IServiceCollection services)
{
    services.InitOAuth2Authenticator();
}

Usage

OAuth2Authenticator

This class holds the request logic for all OAuth2 grant types. Injectable over the IOAuth2Authenticator interface.

private readonly IOAuth2Authenticator _authenticator;

await _authenticator.PasswordGrant(url, clientId, username, password);

await _authenticator.RefreshTokenGrant(url, clientId, refreshToken);

await _authenticator.ClientCredentialsGrant(url, clientId, clientSecret);

After the request, a OAuth2TokenResponse or null returns.

OAuth2TokenHandler

This class holds common logic which is needed for token handling. Injectable over the IOAuth2TokenHandler interface.

RefreshHandler

The refresh handler checks whether the access token is about to expire or has already expired and automatically attempts to renew the token with the refresh token. If a renewal with the refresh token is not possible, a new token is retrieved via the specified callback. The handler always attempts to return a valid token.

private readonly IOAuth2TokenHandler _handler;
private static OAuth2TokenResponse token; // Save the last token somewhere static or distributed.

token = await _handler.RefreshHandler(
    token,
    url,
    clientId,
    async () =>
    {
        // Is executed to obtain a new token if an refresh was not possible or none exists yet.
        return await _authenticator.PasswordGrant(url, clientId, username, password);
    });

ClientCredentialsHandler

The client credentials handler checks whether the access token is about to expire or has already expired and automatically requests a new token.

private readonly IOAuth2TokenHandler _handler;
private static OAuth2TokenResponse token; // Save the last token somewhere static or distributed.

token = await _handler.ClientCredentialsHandler(
    token,
    url,
    clientId,
    clientSecret);

OAuth2TokenResponseExtension

Checks if the token request was successful.

token.Successful()

Checks that the token is not expired.

token.Valid()

API Reference

• OAuth2Authenticator