public async Task Invoke(HttpContext context, IOAuthHandler handler, IJsonObjectWriter objectWriter)
{
Ensure.IsNotNull(context, nameof(context));
Ensure.IsNotNull(handler, nameof(handler));
Ensure.IsNotNull(objectWriter, nameof(objectWriter));
if (context.Request.Path == options.TokenEndpointPath)
{
if (!context.Request.Method.Equals("POST", StringComparison.OrdinalIgnoreCase))
{
WriteResult(context, objectWriter, OAuthResult.InvalidRequest("Token request should use 'POST' method."));
return;
}
if (context.Request.ContentType == null)
{
WriteResult(context, objectWriter, OAuthResult.InvalidRequest("Token request should specify Content-Type."));
return;
}
if (!context.Request.ContentType.StartsWith("application/x-www-form-urlencoded", StringComparison.OrdinalIgnoreCase))
{
WriteResult(context, objectWriter, OAuthResult.InvalidRequest("Token request should use 'application/x-www-form-urlencoded' Content-Type."));
return;
}
var form = await context.Request.ReadFormAsync();
if (form == null)
{
WriteResult(context, objectWriter, OAuthResult.InvalidRequest("Token request should use 'application/x-www-form-urlencoded' Content-Type."));
return;
}
foreach (var pair in form)
{
if (pair.Value.Count > 1)
{
WriteResult(context, objectWriter, OAuthResult.InvalidRequest($"The '{pair.Key}' parameter is repeated."));
return;
}
}
var result = await handler.HandleTokenRequestAsync(new OAuthTokenRequest(form));
if (result != null)
{
WriteResult(context, objectWriter, result);
}
else
{
WriteResult(context, objectWriter, OAuthResult.ServerError("Token request was unhandled."));
}
}
else
{
await next(context);
}
}
private static void WriteResult(HttpContext context, IJsonObjectWriter objectWriter, OAuthResult result)
{
var response = context.Response;
response.StatusCode = result.StatusCode;
if (result.Body != null)
{
response.ContentType = "application/json";
objectWriter.WriteObject(response.Body, result.Body);
}
}