private async Task <AmexCardResponse> AddOrRemoveCardAsync <T>(T requestPayload, string requestUri, AmexOAuthResponse amexOAuthResponse)
{
if (amexOAuthResponse != null)
{
string timestamp = ((int)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds).ToString();
string nonce = string.Concat(timestamp, ":AMEX");
UriBuilder uri = new UriBuilder(requestUri);
//Format = timestamp \n timestamp:AMEX \n method \n path \n port \n\n
string message = string.Format("{0}\n{1}\nPOST\n{2}\n{3}\n{4}\n\n", timestamp, nonce, Regex.Replace(HttpUtility.UrlEncode(uri.Path.ToLowerInvariant()), @"%[a-f0-9]{2}", c => c.Value.ToUpper()), uri.Host.ToLowerInvariant(), uri.Port);
using (HMACSHA256 hmac = new HMACSHA256(Encoding.UTF8.GetBytes(amexOAuthResponse.MacKey)))
{
string mac = Convert.ToBase64String(hmac.ComputeHash(Encoding.UTF8.GetBytes(message)));
// Format -> MAC id="access_token",ts="timestamp",nonce="timestamp:AMEX",mac="HMACSHA256 hash"
string authorizationHeader = string.Format("MAC id=\"{0}\",ts=\"{1}\",nonce=\"{2}\",mac=\"{3}\"", amexOAuthResponse.AccessToken, timestamp, nonce, mac);
Stopwatch timer = Stopwatch.StartNew();
try
{
using (HttpClient httpClient = new HttpClient())
{
httpClient.DefaultRequestHeaders.Accept.Clear();
//httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("MAC", authorizationHeader.ToString());
httpClient.DefaultRequestHeaders.Add("Authorization", authorizationHeader.ToString());
httpClient.DefaultRequestHeaders.Add("X-AMEX-API-KEY", ConfigurationManager.AppSettings[AmexConstants.AmexOAuthClientId]);
httpClient.DefaultRequestHeaders.Add("X-AMEX-MSG-ID", CommerceLog.ActivityId.ToString("N"));
HttpResponseMessage response = await httpClient
.PostAsJsonAsync(requestUri, requestPayload)
.ConfigureAwait(false);
string content = await response.Content.ReadAsStringAsync();
if (response.IsSuccessStatusCode)
{
CommerceLog.Verbose("Received Amex AddOrRemoveCardAsync response. \r\nUri: {0} \r\nContent: {1}", requestUri, content);
return(JsonConvert.DeserializeObject <AmexCardResponse>(content));
}
else
{
CommerceLog.Critical("Unable to get Amex AddOrRemoveCardAsync response. \r\nUri: {0} \r\nStatus: {1} \r\nContent: {2}", null, requestUri, response.StatusCode, content);
}
}
}
finally
{
timer.Stop();
PerformanceInformation.Add(requestUri, string.Format("{0} ms", timer.ElapsedMilliseconds));
}
}
}
return(null);
}
private async Task <AmexOAuthResponse> GetOAuthTokenAsync()
{
// unix epoch format
string timestamp = ((int)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds).ToString();
string nonce = string.Concat(timestamp, ":AMEX");
string clientId = ConfigurationManager.AppSettings[AmexConstants.AmexOAuthClientId];
// Format -> client_id \n timestamp \n timestamp:AMEX \n grant
string message = string.Format("{0}\n{1}\n{2}\nclient_credentials\n", clientId, timestamp, nonce);
using (HMACSHA256 hmac = new HMACSHA256(Encoding.UTF8.GetBytes(ConfigurationManager.AppSettings[AmexConstants.AmexOAuthClientSecret])))
{
string mac = Convert.ToBase64String(hmac.ComputeHash(Encoding.UTF8.GetBytes(message)));
// Format -> MAC id="client_id",ts="timestamp",nonce="timestamp:AMEX",mac="HMACSHA256 hash"
string authenticationHeader = string.Format("MAC id=\"{0}\",ts=\"{1}\",nonce=\"{2}\",mac=\"{3}\"", clientId, timestamp, nonce, mac);
Stopwatch timer = Stopwatch.StartNew();
try
{
using (HttpClient httpClient = new HttpClient())
{
httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Add("Authentication", authenticationHeader);
httpClient.DefaultRequestHeaders.Add("X-AMEX-API-KEY", clientId);
HttpContent httpContent = new StringContent("grant_type=client_credentials&app_spec_info=Apigee&guid_type=privateguid");
httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/x-www-form-urlencoded");
HttpResponseMessage response = await httpClient
.PostAsync(ConfigurationManager.AppSettings[AmexConstants.AmexOAuthUri], httpContent)
.ConfigureAwait(false);
string content = await response.Content.ReadAsStringAsync();
if (response.IsSuccessStatusCode)
{
CommerceLog.Verbose("Received Amex OAuth token. \r\nContent: {0}", content);
return(JsonConvert.DeserializeObject <AmexOAuthResponse>(content));
}
else
{
CommerceLog.Critical("Unable to get Amex OAuth token. \r\nStatus: {0} \r\nContent: {1}", null, response.StatusCode, content);
}
}
}
finally
{
timer.Stop();
PerformanceInformation.Add("Amex OAuth API", string.Format("{0} ms", timer.ElapsedMilliseconds));
}
}
return(null);
}