public async Task <IActionResult> Token(string code, string state, string error, string encoded)
{
WebCache_OAuthData enc;
try
{
string normalbase64 = encoded.Replace("-", "+").Replace("_", "/"); //Convert BASE64URL to normal Base64
int mod = normalbase64.Length % 4;
if (mod == 2)
{
normalbase64 += "==";
}
else if (mod == 3)
{
normalbase64 += "=";
}
enc = JsonConvert.DeserializeObject <WebCache_OAuthData>(Encoding.UTF8.GetString(Convert.FromBase64String(normalbase64)));
if (enc == null) //Bad encoded data, no way to redirect the error
{
return(StatusCode(400, "Bad Request"));
}
}
catch (Exception e) //Bad encoded data, no way to redirect the error
{
_logger.LogError(e, "OAuth Token Error: Bad encoded data.");
return(StatusCode(400, "Bad Request"));
}
WebCache_OAuthAccessTokenWithState errtoken = new WebCache_OAuthAccessTokenWithState();
SessionInfoWithError s = await VerifyTokenAsync(enc.Token);
if (s.Error != null)
{
errtoken.error = s.Error.StatusCode + ": " + s.Error;
return(ReturnResult(enc, errtoken));
}
Dictionary <string, Credentials> providers = GetOAuthProviders();
if (!providers.ContainsKey(enc.Provider))
{
errtoken.error = $"404: Provider {enc.Provider} Not Found";
_logger.LogError($"Provider {enc.Provider} Not Found");
return(ReturnResult(enc, errtoken));
}
Credentials credentials = providers[enc.Provider];
var token = await GetTokenAsync(code, state, credentials, enc.OriginalRedirectUri);
if (token == null)
{
errtoken.error = "400: Bad Request";
return(ReturnResult(enc, errtoken));
}
return(ReturnResult(enc, token));
}
private IActionResult ReturnResult(WebCache_OAuthData enc, WebCache_OAuthAccessTokenWithState token)
{
//If the encoded data has a redirect back, lets redirect the page,
//otherwise return a web page, with the access token in a head meta tag
if (enc.RedirectUri != null)
{
string separator = "?";
if (enc.RedirectUri.Contains("?"))
{
separator = "&";
}
return(Redirect(enc.RedirectUri + separator + token.GetQueryString()));
}
string json = JsonConvert.SerializeObject(token, Formatting.None).Replace("\r", "").Replace("\n", "");
return(new ContentResult {
ContentType = "text/html", StatusCode = (int)HttpStatusCode.OK, Content = "<html><head><meta name=\"AccessToken\" content=\"" + HttpUtility.HtmlEncode(json) + "\"/></head></html>"
});
}
private async Task <WebCache_OAuthAccessTokenWithState> GetTokenAsync(string code, string state, Credentials credentials, string redirecturi)
{
try
{
Dictionary <string, string> postdata = new Dictionary <string, string>();
postdata.Add("grant_type", "authorization_code");
postdata.Add("code", code);
postdata.Add("client_id", credentials.Id);
postdata.Add("client_secret", credentials.Secret);
postdata.Add("redirect_uri", redirecturi);
using (var client = new HttpClient())
{
string accept = "application/json";
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, credentials.TokenUri);
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue(accept));
request.Content = new FormUrlEncodedContent(postdata);
request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/x-www-form-urlencoded");
HttpResponseMessage response = await client.SendAsync(request, HttpCompletionOption.ResponseContentRead);
if (!response.IsSuccessStatusCode)
{
_logger.LogError($"Unable to get token from provider at {credentials.TokenUri}, Status Code: {response.StatusCode} Error: {response.ReasonPhrase ?? "None"}");
return(null);
}
WebCache_OAuthAccessTokenWithState at = JsonConvert.DeserializeObject <WebCache_OAuthAccessTokenWithState>(await response.Content.ReadAsStringAsync());
at.state = state;
return(at);
}
}
catch (Exception e)
{
_logger.LogError(e, $"Unable to get token from provider at {credentials.TokenUri} Exception caught");
return(null);
}
}
public static string GetQueryString(this WebCache_OAuthAccessTokenWithState at) => "access_token=" + HttpUtility.UrlEncode(at.access_token) + "&token_type=" + HttpUtility.UrlEncode(at.token_type) + "&expires_in=" + HttpUtility.UrlEncode(at.expires_in.ToString()) + "&state=" + HttpUtility.UrlEncode(at.state);
