public async Task<HelloSignCallback> ParseAsync(HttpRequestMessage request)
{
var p = new InMemoryMultipartFormDataStreamProvider();
await request.Content.ReadAsMultipartAsync(p);
var cb = HelloSignCallback.Parse(p.FormData["json"]);
// only validate the hash if the ApiKey has been set
if (string.IsNullOrEmpty(ApiKey))
{
var hash = HelloSignUtilities.GenerateEventHash(ApiKey, cb.Event.EventTime, cb.Event.EventType);
if (string.IsNullOrEmpty(hash))
{
throw new Exception(string.Format("Was not able to compute event hash:\r\n{0}", p.FormData["json"]));
}
if (hash != cb.Event.EventHash)
{
throw new Exception(string.Format("Event hash does not match expected value; This event may not be genuine. Make sure this API key matches the one on the account generating callbacks:\r\n{0}", p.FormData["json"]));
}
}
return cb;
}