Merge pull request #72 from cabauman/colt_googleIdToken

Add method to sign in with Google ID token

Author: bezysoftware

src/Firebase.Auth/FirebaseAuthProvider.cs

@@ -89,6 +89,20 @@ public async Task<FirebaseAuthLink> SignInWithOAuthAsync(FirebaseAuthType authTy
             return await this.ExecuteWithPostContentAsync(GoogleIdentityUrl, content).ConfigureAwait(false);
         }
 
+        /// <summary>
+        /// Using the provided Id token from google signin, get the firebase auth with token and basic user credentials.
+        /// </summary>
+        /// <param name="authType"> The auth type. </param>
+        /// <param name="idToken"> The Id token retrieved from google signin </param>
+        /// <returns> The <see cref="FirebaseAuth"/>. </returns>
+        public async Task<FirebaseAuthLink> SignInWithGoogleIdTokenAsync(string idToken)
+        {
+            var providerId = this.GetProviderId(FirebaseAuthType.Google);
+            var content = $"{{\"postBody\":\"id_token={idToken}&providerId={providerId}\",\"requestUri\":\"http://localhost\",\"returnSecureToken\":true}}";
+
+            return await this.ExecuteWithPostContentAsync(GoogleIdentityUrl, content).ConfigureAwait(false);
+        }
+
         /// <summary>
         /// Sign in user anonymously. He would still have a user id and access token generated, but name and other personal user properties will be null.
         /// </summary>