The Question
Hello, I need to authenticate to an API wich needs OAuth encryption.
I'm in the right direction but I am sure something is wrong with my signature base string. Since the HMACSHA1 Hash is based on a Key and BaseString, I get a wrong oauth_signature.
OAuth Signing Process
So far
I have been able to collect all the required pieces of data, which includes:
- Consumer Key
- Consumer Secret
- Acces Token
- Acces Secret
- Sha1Hased Value (Based on Key and Message, where Message is the signature Base string)
- Signature Base String
The Problem
I get a HTTP(401 Bad Request) returned because of a invalid signature.
note: I'm pretty sure it is how I build my Signature Base String. For info about the API Docs I used, please check bottom page.
The Code
GetOAuthToken (Doing the actual request)
public static string GetAuthorizationToken()
{
string TimeInSecondsSince1970 = ((int)(DateTime.UtcNow - new DateTime(1970, 1, 1)).TotalSeconds).ToString();
string Nonce = System.Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(TimeInSecondsSince1970
+ TimeInSecondsSince1970 + TimeInSecondsSince1970));
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(GetAppleApiUrl.GetUrl(AppleApiUrl.SESSION_TOKEN));
httpWebRequest.Method = "GET";
string consumer_secret = Uri.EscapeDataString(Settings.SettingsManager.consumer_secret);
string token_secret = Uri.EscapeDataString(Settings.SettingsManager.access_secret);
string signature_base_string = GetSignatureBaseString(TimeInSecondsSince1970, Nonce);
string SHA1HASH = GetSha1Hash(consumer_secret + "&" + token_secret, signature_base_string);
string Header =
"OAuth realm=" + '"' + "ADM" + '"' + "," +
"oauth_consumer_key=" + '"' + Settings.SettingsManager.consumer_key + '"' + "," +
"oauth_token=" + '"' + Settings.SettingsManager.access_token + '"' + "," +
"oauth_signature_method=" + '"' + "HMAC-SHA1" + '"' + "," +
"oauth_signature= " + '"' + SHA1HASH + '"' + "," +
"oauth_timestamp=" + '"' + TimeInSecondsSince1970 + '"' + "," +
"oauth_nonce=" + '"' + Nonce + '"' + "," +
"oauth_version=" + '"' + "1.0" + '"' + ",";
httpWebRequest.Headers.Add(HttpRequestHeader.Authorization, Header);
var Result = httpWebRequest.GetResponse();
return Result.ToString();
}
GetSha1Hash
public static string GetSha1Hash(string key, string message)
{
var encoding = new System.Text.ASCIIEncoding();
byte[] keyBytes = encoding.GetBytes(key);
byte[] messageBytes = encoding.GetBytes(message);
string Sha1Result = string.Empty;
using (HMACSHA1 SHA1 = new HMACSHA1(keyBytes))
{
var Hashed = SHA1.ComputeHash(messageBytes);
Sha1Result = Convert.ToBase64String(Hashed);
}
return Sha1Result;
}
GetSignatureBaseString
public static string GetSignatureBaseString(string TimeStamp, string Nonce)
{
//1.Convert the HTTP Method to uppercase and set the output string equal to this value.
string Signature_Base_String = "Get";
Signature_Base_String = Signature_Base_String.ToUpper();
//2.Append the ‘&’ character to the output string.
Signature_Base_String = Signature_Base_String + "&";
//3.Percent encode the URL and append it to the output string.
string PercentEncodedURL = Uri.EscapeDataString(GetAppleApiUrl.GetUrl(AppleApiUrl.SESSION_TOKEN));
Signature_Base_String = Signature_Base_String + PercentEncodedURL;
//4.Append the ‘&’ character to the output string.
Signature_Base_String = Signature_Base_String + "&";
//5.append parameter string to the output string.
Signature_Base_String = Signature_Base_String + Uri.EscapeDataString("oauth_consumer_key=" + Settings.SettingsManager.consumer_key);
Signature_Base_String = Signature_Base_String + Uri.EscapeDataString("&oauth_token=" + Settings.SettingsManager.access_token);
Signature_Base_String = Signature_Base_String + Uri.EscapeDataString("&oauth_signature_method=" +"HMAC-SHA1");
Signature_Base_String = Signature_Base_String + Uri.EscapeDataString("&oauth_timestamp=" + TimeStamp);
Signature_Base_String = Signature_Base_String + Uri.EscapeDataString("&oauth_nonce=" + Nonce);
Signature_Base_String = Signature_Base_String + Uri.EscapeDataString("&oauth_version=" + "1.0");
return Signature_Base_String;
}
Result (Fiddler)
API Doc