OAUTHnesia for Windows 8 Metro Apps C#

OAUTHnesia.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Net.Http;
using System.Threading.Tasks;

/**
 * OAUTHnesia for Windows 8 Metro Apps C#
 * 
 * OAUTH v1.0a library for C# to access Urbanesia API
 * 
 * @package	OAUTHnesia
 * @subpackage	Windows 8 Metro Apps C#
 * @category	Library
 * @author	Batista R. Harahap <[email protected]>
 * @link	http://www.bango29.com
 * @license	MIT License - http://www.opensource.org/licenses/mit-license.php
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a 
 * copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the 
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
 * IN THE SOFTWARE.
 */
namespace Urbanesia.Libraries
{
    class OAUTHnesia
    {
        private string
            ConsumerKey,
            ConsumerSecret,
            UserKey,
            UserSecret,
            SafeEncode,
            ApiUri;

        public static string 
            BASE_URL = "http://api1.urbanesia.com/",
            OAUTH_SAFE_ENCODE = "1",
            OAUTH_NO_SAFE_ENCODE = "0";

        public OAUTHnesia(string consumerKey, string consumerSecret, string safeEncode)
        {
            this.ConsumerKey = consumerKey;
            this.ConsumerSecret = consumerSecret;
            this.SafeEncode = safeEncode;
        }

        public OAUTHnesia(string consumerKey, string consumerSecret, string userKey, string userSecret, string safeEncode)
        {
            this.ConsumerKey = consumerKey;
            this.ConsumerSecret = consumerSecret;
            this.UserKey = userKey;
            this.UserSecret = userSecret;
            this.SafeEncode = safeEncode;
        }

        public async Task<string> Oauth(string uri = "", string post = "", string get = "", bool signWithUserTokens = false)
        {
            // Set URI
            this.ApiUri = uri;

            // Default POST body
            string _defaultPost = String.Format(
                "oauth_consumer_key={0}&oauth_nonce={1}&oauth_signature_method=HMAC-SHA1&oauth_timestamp={2}"+
                    "&oauth_version=1.0",
                this.ConsumerKey,
                GetNonce(),
                Utils.GetUnixTimeAsString()
            );

            // Add User Token Key to default POST body if requested
            if (signWithUserTokens == true)
                _defaultPost += String.Format("{0}&oauth_token={1}", _defaultPost, this.UserKey);

            // Merge default POST with actual POST
            if (post == "")
            {
                post = _defaultPost;
            }
            else
            {
                post += "&" + _defaultPost;
            }

            // Add Safe Encode if requested
            if (this.SafeEncode == OAUTH_SAFE_ENCODE)
            {
                post += "&safe_encode=" + OAUTH_SAFE_ENCODE;
            }

            // Merge POST + GET and sort the array
            string requestify = this.Sortify(post + "&" + get);

            // Encode for OAUTH
            requestify = EncodeForOauth(requestify);

            // Base Signature
            string baseSig = GenerateBaseSignature(requestify);
            Debug.WriteLine("Base Signature: " + baseSig);

            // Signature
            string signature = signWithUserTokens == true ? 
                Utils.HmacSha1(baseSig, String.Format("{0}&{1}", this.ConsumerSecret, this.UserSecret)) :
                Utils.HmacSha1(baseSig, String.Format("{0}&", this.ConsumerSecret));

            // Build URL
            string oauthSig = String.Format("?oauth_signature={0}", signature);
            // Replace all %20 to %2B
            get = get.Replace("%20", "%2B");
            string url = String.Format("{0}{1}{2}&{3}", BASE_URL, ApiUri, oauthSig, get);

            return await SendRequest(url, GeneratePostContent(post));
        }

        private FormUrlEncodedContent GeneratePostContent(string post)
        {
            string[] sp = post.Split('&');
            Dictionary<string, string> dict = new Dictionary<string, string>();

            foreach(string vals in sp)
            {
                string[] temp = vals.Split('=');
                dict.Add(temp[0], temp[1]);
            }
            return new FormUrlEncodedContent(dict);
        }

        private async Task<string> SendRequest(string url, FormUrlEncodedContent post)
        {
            HttpClient http = new HttpClient() { MaxResponseContentBufferSize = 256 * 1024 };
            HttpResponseMessage response = await http.PostAsync(url, post);
            response.EnsureSuccessStatusCode();

            return await response.Content.ReadAsStringAsync();
        }

        private string GenerateBaseSignature(string s)
        {
            return String.Format("POST&{0}&{1}", Utils.UrlEncode(BASE_URL + this.ApiUri), Utils.UrlEncode(s));
        }

        private String EncodeForOauth(string s)
        {
            string[] sp = s.Split('&');
            string stify = "";
            for (int i = 0, j = 0, max = sp.Length; i < max; i++)
            {
                if (j == 1)
                    stify += "&";

                string[] temp = sp[i].Split('=');
                stify += Utils.UrlEncode(temp[0]) + "=" + Utils.UrlEncode(temp[1]);
                j = 1;
            }
            return stify;
        }

        private string Sortify(string s)
        {
            string[] sp = s.Split('&');
            Array.Sort(sp);
            string stify = "";
            for (int i = 0, j = 0, max = sp.Length; i < max; i++)
            {
                if (j == 1)
                    stify += "&";

                string[] temp = sp[i].Split('=');
                stify += temp[0] + "=" + temp[1];
                j = 1;
            }
            return stify;
        }

        private string GetNonce()
        {
            return Utils.Md5("FSoNTivj8iyqucRI6tx88NYICcuyrdVovJMqBwLz" + DateTime.UtcNow.Millisecond);
        }
    }
}

Utils.cs

using System;
using Windows.Security.Cryptography;
using Windows.Security.Cryptography.Core;
using Windows.Storage.Streams;

/**
 * OAUTHnesia for Windows 8 Metro Apps C#
 * 
 * OAUTH v1.0a library for C# to access Urbanesia API
 * 
 * @package	OAUTHnesia
 * @subpackage	Windows 8 Metro Apps C#
 * @category	Library
 * @author	Batista R. Harahap <[email protected]>
 * @link	http://www.bango29.com
 * @license	MIT License - http://www.opensource.org/licenses/mit-license.php
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a 
 * copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the 
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
 * IN THE SOFTWARE.
 */
namespace Urbanesia.Libraries
{
    class Utils
    {
        public static string
            CONSUMER_KEY = "CONSUMER_KEY",
            CONSUMER_SECRET = "CONSUMER_SECRET";

        public static string Md5(string str)
        {
            var alg = HashAlgorithmProvider.OpenAlgorithm("MD5");
            IBuffer buff = CryptographicBuffer.ConvertStringToBinary(str, BinaryStringEncoding.Utf8);
            var hashed = alg.HashData(buff);
            var res = CryptographicBuffer.EncodeToHexString(hashed);
            return res;
        }

        public static string GetUnixTimeAsString()
        {
            TimeSpan ts = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0));
            return Convert.ToString(ts.TotalSeconds);
        }

        public static int GetUnixTimeAsInteger()
        {
            TimeSpan ts = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0));
            return Convert.ToInt32(ts.TotalSeconds);
        }

        public static long GetUnixTimeAsLong()
        {
            TimeSpan ts = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0));
            return Convert.ToInt64(ts.TotalSeconds);
        }

        public static string HmacSha1(string baseString, string keyString)
        {
            var crypt = MacAlgorithmProvider.OpenAlgorithm("HMAC_SHA1");
            var buffer = CryptographicBuffer.ConvertStringToBinary(baseString, BinaryStringEncoding.Utf8);
            var keyBuffer = CryptographicBuffer.ConvertStringToBinary(keyString, BinaryStringEncoding.Utf8);
            var key = crypt.CreateKey(keyBuffer);

            var sigBuffer = CryptographicEngine.Sign(key, buffer);
            string signature = CryptographicBuffer.EncodeToBase64String(sigBuffer);
            return signature;
        }

        public static string UrlEncode(string s)
        {
            switch (s)
            {
                case "+":
                    return "%2B";
                default:
                    return System.Uri.EscapeDataString(s);
            }
        }
    }
}