public static AppleAccount FromUrl(string url)
{
var parameters = Util.ParseUrlParameters(url);
var idToken = JwtToken.Decode(parameters["id_token"]);
return(new AppleAccount
{
IdToken = idToken,
UserId = idToken.Subject,
Email = idToken.Payload.ContainsKey("email") ? idToken.Payload["email"]?.ToString() : null,
Name = idToken.Payload.ContainsKey("name") ? idToken.Payload["name"]?.ToString() : null,
AccessToken = parameters.ContainsKey("access_token") ? parameters["access_token"] : null,
RefreshToken = parameters.ContainsKey("refresh_token") ? parameters["refresh_token"] : null,
});
}
public async Task <AppleAccount> ExchangeTokenAsync(string code)
{
var client = new HttpClient();
var header = new ProductHeaderValue("Xamarin", "1.0");
var userAgentHeader = new ProductInfoHeaderValue(header);
client.DefaultRequestHeaders.UserAgent.Add(userAgentHeader);
var secret = GenerateClientSecretJWT(P8FileContents);
var resp = await client.PostAsync(AppleTokenUrl, new FormUrlEncodedContent(new Dictionary <string, string>
{
{ "grant_type", "authorization_code" },
{ "code", code },
{ "redirect_uri", RedirectUri.OriginalString },
{ "client_id", ServerId },
{ "client_secret", secret },
}));
resp.EnsureSuccessStatusCode();
var respData = await resp.Content.ReadAsStringAsync();
var respProperties = Newtonsoft.Json.JsonConvert.DeserializeObject <Dictionary <string, string> >(respData);
var idToken = JwtToken.Decode(respProperties["id_token"]);
var accessToken = respProperties?["access_token"];
var refreshToken = respProperties?["refresh_token"];
string email = idToken.Payload.ContainsKey("email") ? idToken.Payload["email"]?.ToString() : null;
string name = idToken.Payload.ContainsKey("name") ? idToken.Payload["name"]?.ToString() : null;
if (name == null)
{
try
{
JObject obj = JObject.Parse(respData);
name = obj["user"]["name"]["firstName"].ToString() ?? null;
}
catch (Exception ex)
{
name = null;
}
}
// Validate id token
if (!idToken.Issuer.Equals(AppleJwtUrl))
{
throw new ProtocolViolationException($"Invalid id_token issuer received: Expected `{AppleJwtUrl}` but observed `{idToken.Issuer}`");
}
if (!idToken.AccessTokenHash.Equals(Util.Sha256AtHash(accessToken)))
{
throw new ProtocolViolationException("Access Token Hash did not match actual access token's hash");
}
if (!idToken.Algorithm.Equals("RS256"))
{
throw new ProtocolViolationException($"Invalid id_token algorithm returned: Expected `RS256` but observed `{idToken.Algorithm}`");
}
// Verify audience claim
if (!idToken.Audience.Equals(ServerId))
{
throw new ProtocolViolationException($"The id_token 'aud' claim does not match the provided clientId value.")
;
}
if (idToken.Expiration < DateTime.UtcNow)
{
throw new ProtocolViolationException($"The id_token is expired");
}
// TODO: Verify the signature of the JWT token
return(new AppleAccount
{
Email = email,
Name = name,
AccessToken = accessToken,
RefreshToken = refreshToken,
IdToken = idToken
});
}