/// <summary>
/// To get a request without sending a push notification call this method.
/// This method will throw an ArgumentException if there is an issue with the input.
/// </summary>
/// <param name="subscription">The PushSubscription you wish to send the notification to.</param>
/// <param name="payload">The payload you wish to send to the user</param>
/// <param name="options">
/// Options for the GCM API key and vapid keys can be passed in if they are unique for each
/// notification.
/// </param>
/// <returns>A HttpRequestMessage object that can be sent.</returns>
public HttpRequestMessage GenerateRequestDetails(PushSubscription subscription, string payload,
Dictionary <string, object> options = null)
{
if (!Uri.IsWellFormedUriString(subscription.Endpoint, UriKind.Absolute))
{
throw new ArgumentException(@"You must pass in a subscription with at least a valid endpoint");
}
var request = new HttpRequestMessage(HttpMethod.Post, subscription.Endpoint);
if (!string.IsNullOrEmpty(payload) && (string.IsNullOrEmpty(subscription.Auth) ||
string.IsNullOrEmpty(subscription.P256DH)))
{
throw new ArgumentException(
@"To send a message with a payload, the subscription must have 'auth' and 'p256dh' keys.");
}
var currentGcmApiKey = _gcmApiKey;
var currentVapidDetails = _vapidDetails;
var timeToLive = DefaultTtl;
var extraHeaders = new Dictionary <string, object>();
if (options != null)
{
var validOptionsKeys = new List <string> {
"headers", "gcmAPIKey", "vapidDetails", "TTL"
};
foreach (var key in options.Keys)
{
if (!validOptionsKeys.Contains(key))
{
throw new ArgumentException(key + " is an invalid options. The valid options are" +
string.Join(",", validOptionsKeys));
}
}
if (options.ContainsKey("headers"))
{
var headers = options["headers"] as Dictionary <string, object>;
extraHeaders = headers ?? throw new ArgumentException("options.headers must be of type Dictionary<string,object>");
}
if (options.ContainsKey("gcmAPIKey"))
{
var gcmApiKey = options["gcmAPIKey"] as string;
currentGcmApiKey = gcmApiKey ?? throw new ArgumentException("options.gcmAPIKey must be of type string");
}
if (options.ContainsKey("vapidDetails"))
{
var vapidDetails = options["vapidDetails"] as VapidDetails;
currentVapidDetails = vapidDetails ?? throw new ArgumentException("options.vapidDetails must be of type VapidDetails");
}
if (options.ContainsKey("TTL"))
{
var ttl = options["TTL"] as int?;
if (ttl == null)
{
throw new ArgumentException("options.TTL must be of type int");
}
//at this stage ttl cannot be null.
timeToLive = (int)ttl;
}
}
string cryptoKeyHeader = null;
request.Headers.Add("TTL", timeToLive.ToString());
foreach (var header in extraHeaders)
{
request.Headers.Add(header.Key, header.Value.ToString());
}
if (!string.IsNullOrEmpty(payload))
{
if (string.IsNullOrEmpty(subscription.P256DH) || string.IsNullOrEmpty(subscription.Auth))
{
throw new ArgumentException(
@"Unable to send a message with payload to this subscription since it doesn't have the required encryption key");
}
var encryptedPayload = TestEncryptor.Encrypt(subscription.P256DH, subscription.Auth, payload);
request.Content = new ByteArrayContent(encryptedPayload.Payload);
request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
request.Content.Headers.ContentLength = encryptedPayload.Payload.Length;
request.Content.Headers.ContentEncoding.Add("aesgcm");
request.Headers.Add("Encryption", "salt=" + encryptedPayload.Base64EncodeSalt());
cryptoKeyHeader = @"dh=" + encryptedPayload.Base64EncodePublicKey();
}
else
{
request.Content = new ByteArrayContent(new byte[0]);
request.Content.Headers.ContentLength = 0;
}
var isGcm = subscription.Endpoint.StartsWith(@"https://android.googleapis.com/gcm/send");
var isFcm = subscription.Endpoint.StartsWith(@"https://fcm.googleapis.com/fcm/send/");
if (isGcm)
{
if (!string.IsNullOrEmpty(currentGcmApiKey))
{
request.Headers.TryAddWithoutValidation("Authorization", "key=" + currentGcmApiKey);
}
}
else if (currentVapidDetails != null)
{
var uri = new Uri(subscription.Endpoint);
var audience = uri.Scheme + @"://" + uri.Host;
var vapidHeaders = VapidHelper.GetVapidHeaders(audience, currentVapidDetails.Subject,
currentVapidDetails.PublicKey, currentVapidDetails.PrivateKey, currentVapidDetails.Expiration);
request.Headers.Add(@"Authorization", vapidHeaders["Authorization"]);
if (string.IsNullOrEmpty(cryptoKeyHeader))
{
cryptoKeyHeader = vapidHeaders["Crypto-Key"];
}
else
{
cryptoKeyHeader += @";" + vapidHeaders["Crypto-Key"];
}
}
else if (isFcm && !string.IsNullOrEmpty(currentGcmApiKey))
{
request.Headers.TryAddWithoutValidation("Authorization", "key=" + currentGcmApiKey);
}
request.Headers.Add("Crypto-Key", cryptoKeyHeader);
return(request);
}
