OAuth 1.0a 的 C# 代码实现
补充：由于很多人跟我要API Proxy，特意在codeplex建了个项目。大家可以去下载。 地址： http://tinalight.codeplex.com/
大概是在2月底的时候研究了一下新浪微博开放API，只做到登录通过获取了第一把数据后就没有时间了。。因此一直搁置了下来。现在把当时调用OAuth进行验证的代码分享出来，希望对开放API感兴趣的同学有所帮助。
OAuth 1.0a 的代码是根据Google提供的OAuth 1.0进行修改的，现在记得不是很清楚了。。记得当时是加了个参数啥的。本代码经过新浪开放API测试，大家可以放心使用。
当时修改这个的时候手头没有任何资料，只有新浪微博开放API里提供的文档，我基本上是对比了多份文档之间的区别。。。才“猜”是不是要加个参数。。。还好猜对了。。
我的项目是一个Silverlight项目，因为新浪微博开放API不提供策略文件（=_=!，基于安全吧。。），因此只好自己写了一个API代理来实现。如果有需要的同学（Silverlight项目才需要！其它不需要！）可以联系我，在新浪微博 @happycharles 就可以！
废话少说~上代码！~
public class OAuthBase
{
/// <summary>
/// Provides a predefined set of algorithms that are supported officially by the protocol
/// </summary>
public enum SignatureTypes
{
HMACSHA1,
PLAINTEXT,
RSASHA1
}
/// <summary>
/// Provides an internal structure to sort the query parameter
/// </summary>
protected class QueryParameter
{
private string name = null;
private string value = null;
public QueryParameter(string name, string value)
{
this.name = name;
this.value = value;
}
public string Name
{
get { return name; }
}
public string Value
{
get { return value; }
}
}
/// <summary>
/// Comparer class used to perform the sorting of the query parameters
/// </summary>
protected class QueryParameterComparer : IComparer<QueryParameter>
{
#region IComparer<QueryParameter> Members
public int Compare(QueryParameter x, QueryParameter y)
{
if (x.Name == y.Name)
{
return string.Compare(x.Value, y.Value);
}
else
{
return string.Compare(x.Name, y.Name);
}
}
#endregion
}
protected const string OAuthVersion = "1.0a";
protected const string OAuthParameterPrefix = "oauth_";
//
// List of know and used oauth parameters' names
//
protected const string OAuthConsumerKeyKey = "oauth_consumer_key";
protected const string OAuthCallbackKey = "oauth_callback";
protected const string OAuthVersionKey = "oauth_version";
protected const string OAuthSignatureMethodKey = "oauth_signature_method";
protected const string OAuthSignatureKey = "oauth_signature";
protected const string OAuthTimestampKey = "oauth_timestamp";
protected const string OAuthNonceKey = "oauth_nonce";
protected const string OAuthTokenKey = "oauth_token";
protected const string OAuthVerifier = "oauth_verifier";
protected const string OAuthTokenSecretKey = "oauth_token_secret";
protected const string HMACSHA1SignatureType = "HMAC-SHA1";
protected const string PlainTextSignatureType = "PLAINTEXT";
protected const string RSASHA1SignatureType = "RSA-SHA1";
protected Random random = new Random();
protected string unreservedChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.~";
/// <summary>
/// Helper function to compute a hash value
/// </summary>
/// <param name="hashAlgorithm">The hashing algoirhtm used. If that algorithm needs some initialization, like HMAC and its derivatives, they should be initialized prior to passing it to this function</param>
/// <param name="data">The data to hash</param>
/// <returns>a Base64 string of the hash value</returns>
private string ComputeHash(HashAlgorithm hashAlgorithm, string data)
{
if (hashAlgorithm == null)
{
throw new ArgumentNullException("hashAlgorithm");
}
if (string.IsNullOrEmpty(data))
{
throw new ArgumentNullException("data");
}
byte[] dataBuffer = System.Text.Encoding.UTF8.GetBytes(data);
byte[] hashBytes = hashAlgorithm.ComputeHash(dataBuffer);
return Convert.ToBase64String(hashBytes);
}
/// <summary>
/// Internal function to cut out all non oauth query string parameters (all parameters not begining with "oauth_")
/// </summary>
/// <param name="parameters">The query string part of the Url</param>
/// <returns>A list of QueryParameter each containing the parameter name and value</returns>
private List<QueryParameter> GetQueryParameters(string parameters)
{
if (parameters.StartsWith("?"))
{
parameters = parameters.Remove(0, 1);
}
List<QueryParameter> result = new List<QueryParameter>();
if (!string.IsNullOrEmpty(parameters))
{
string[] p = parameters.Split('&');
foreach (string s in p)
{
if (!string.IsNullOrEmpty(s) && !s.StartsWith(OAuthParameterPrefix))
{
if (s.IndexOf('=') > -1)
{
string[] temp = s.Split('=');
result.Add(new QueryParameter(temp[0], temp[1]));
}
else
{
result.Add(new QueryParameter(s, string.Empty));
}
}
}
}
return result;
}
/// <summary>
/// This is a different Url Encode implementation since the default .NET one outputs the percent encoding in lower case.
/// While this is not a problem with the percent encoding spec, it is used in upper case throughout OAuth
/// </summary>
/// <param name="value">The value to Url encode</param>
/// <returns>Returns a Url encoded string</returns>
protected string UrlEncode(string value)
{
StringBuilder result = new StringBuilder();
foreach (char symbol in value)
{
if (unreservedChars.IndexOf(symbol) != -1)
{
result.Append(symbol);
}
else
{
result.Append('%' + String.Format("{0:X2}", (int)symbol));
}
}
return result.ToString();
}
/// <summary>
/// Normalizes the request parameters according to the spec
/// </summary>
/// <param name="parameters">The list of parameters already sorted</param>
/// <returns>a string representing the normalized parameters</returns>
protected string NormalizeRequestParameters(IList<QueryParameter> parameters)
{
StringBuilder sb = new StringBuilder();
QueryParameter p = null;
for (int i = 0; i < parameters.Count; i++)
{
p = parameters[i];
sb.AppendFormat("{0}={1}", p.Name, p.Value);
if (i < parameters.Count - 1)
{
sb.Append("&");
}
}
return sb.ToString();
}
/// <summary>
/// Generate the signature base that is used to produce the signature
/// </summary>
/// <param name="url">The full url that needs to be signed including its non OAuth url parameters</param>
/// <param name="consumerKey">The consumer key</param>
/// <param name="token">The token, if available. If not available pass null or an empty string</param>
/// <param name="tokenSecret">The token secret, if available. If not available pass null or an empty string</param>
/// <param name="httpMethod">The http method used. Must be a valid HTTP method verb (POST,GET,PUT, etc)</param>
/// <param name="signatureType">The signature type. To use the default values use <see cref="OAuthBase.SignatureTypes">OAuthBase.SignatureTypes</see>.</param>
/// <returns>The signature base</returns>
public string GenerateSignatureBase(Uri url, string consumerKey, string token, string tokenSecret, string httpMethod, string timeStamp, string nonce, string signatureType, string verifier, out string normalizedUrl, out string normalizedRequestParameters)
{
if (token == null)
{
token = string.Empty;
}
if (tokenSecret == null)
{
tokenSecret = string.Empty;
}
if (string.IsNullOrEmpty(consumerKey))
{
throw new ArgumentNullException("consumerKey");
}
if (string.IsNullOrEmpty(httpMethod))
{
throw new ArgumentNullException("httpMethod");
}
if (string.IsNullOrEmpty(signatureType))
{
throw new ArgumentNullException("signatureType");
}
normalizedUrl = null;
normalizedRequestParameters = null;
List<QueryParameter> parameters = GetQueryParameters(url.Query);
parameters.Add(new QueryParameter(OAuthVersionKey, OAuthVersion));
parameters.Add(new QueryParameter(OAuthNonceKey, nonce));
parameters.Add(new QueryParameter(OAuthTimestampKey, timeStamp));
parameters.Add(new QueryParameter(OAuthSignatureMethodKey, signatureType));
parameters.Add(new QueryParameter(OAuthConsumerKeyKey, consumerKey));
if (!string.IsNullOrEmpty(token))
{
parameters.Add(new QueryParameter(OAuthTokenKey, token));
}
if (!string.IsNullOrEmpty(verifier))
{
parameters.Add(new QueryParameter(OAuthVerifier, verifier));
}
parameters.Sort(new QueryParameterComparer());
normalizedUrl = string.Format("{0}://{1}", url.Scheme, url.Host);
if (!((url.Scheme == "http" && url.Port == 80) || (url.Scheme == "https" && url.Port == 443)))
{
normalizedUrl += ":" + url.Port;
}
normalizedUrl += url.AbsolutePath;
normalizedRequestParameters = NormalizeRequestParameters(parameters);
StringBuilder signatureBase = new StringBuilder();
signatureBase.AppendFormat("{0}&", httpMethod.ToUpper());
signatureBase.AppendFormat("{0}&", UrlEncode(normalizedUrl));
signatureBase.AppendFormat("{0}", UrlEncode(normalizedRequestParameters));
return signatureBase.ToString();
}
/// <summary>
/// Generate the signature value based on the given signature base and hash algorithm
/// </summary>
/// <param name="signatureBase">The signature based as produced by the GenerateSignatureBase method or by any other means</param>
/// <param name="hash">The hash algorithm used to perform the hashing. If the hashing algorithm requires initialization or a key it should be set prior to calling this method</param>
/// <returns>A base64 string of the hash value</returns>
public string GenerateSignatureUsingHash(string signatureBase, HashAlgorithm hash)
{
return ComputeHash(hash, signatureBase);
}
/// <summary>
/// Generates a signature using the HMAC-SHA1 algorithm
/// </summary>
/// <param name="url">The full url that needs to be signed including its non OAuth url parameters</param>
/// <param name="consumerKey">The consumer key</param>
/// <param name="consumerSecret">The consumer seceret</param>
/// <param name="token">The token, if available. If not available pass null or an empty string</param>
/// <param name="tokenSecret">The token secret, if available. If not available pass null or an empty string</param>
/// <param name="httpMethod">The http method used. Must be a valid HTTP method verb (POST,GET,PUT, etc)</param>
/// <returns>A base64 string of the hash value</returns>
public string GenerateSignature(Uri url, string consumerKey, string consumerSecret, string token, string tokenSecret, string httpMethod, string timeStamp, string nonce, string verifier, out string normalizedUrl, out string normalizedRequestParameters)
{
return GenerateSignature(url, consumerKey, consumerSecret, token, tokenSecret, httpMethod, timeStamp, nonce, SignatureTypes.HMACSHA1, verifier, out normalizedUrl, out normalizedRequestParameters);
}
/// <summary>
/// Generates a signature using the specified signatureType
/// </summary>
/// <param name="url">The full url that needs to be signed including its non OAuth url parameters</param>
/// <param name="consumerKey">The consumer key</param>
/// <param name="consumerSecret">The consumer seceret</param>
/// <param name="token">The token, if available. If not available pass null or an empty string</param>
/// <param name="tokenSecret">The token secret, if available. If not available pass null or an empty string</param>
/// <param name="httpMethod">The http method used. Must be a valid HTTP method verb (POST,GET,PUT, etc)</param>
/// <param name="signatureType">The type of signature to use</param>
/// <returns>A base64 string of the hash value</returns>
public string GenerateSignature(Uri url, string consumerKey, string consumerSecret, string token, string tokenSecret, string httpMethod, string timeStamp, string nonce, SignatureTypes signatureType, string verifier, out string normalizedUrl, out string normalizedRequestParameters)
{
normalizedUrl = null;
normalizedRequestParameters = null;
switch (signatureType)
{
case SignatureTypes.PLAINTEXT:
return HttpUtility.UrlEncode(string.Format("{0}&{1}", consumerSecret, tokenSecret));
case SignatureTypes.HMACSHA1:
string signatureBase = GenerateSignatureBase(url, consumerKey, token, tokenSecret, httpMethod, timeStamp, nonce, HMACSHA1SignatureType, verifier, out normalizedUrl, out normalizedRequestParameters);
HMACSHA1 hmacsha1 = new HMACSHA1();
hmacsha1.Key = Encoding.UTF8.GetBytes(string.Format("{0}&{1}", UrlEncode(consumerSecret), string.IsNullOrEmpty(tokenSecret) ? "" : UrlEncode(tokenSecret)));
return GenerateSignatureUsingHash(signatureBase, hmacsha1);
case SignatureTypes.RSASHA1:
throw new NotImplementedException();
default:
throw new ArgumentException("Unknown signature type", "signatureType");
}
}
/// <summary>
/// Generate the timestamp for the signature
/// </summary>
/// <returns></returns>
public virtual string GenerateTimeStamp()
{
// Default implementation of UNIX time of the current UTC time
TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
return Convert.ToInt64(ts.TotalSeconds).ToString();
}
/// <summary>
/// Generate a nonce
/// </summary>
/// <returns></returns>
public virtual string GenerateNonce()
{
// Just a simple implementation of a random number between 123400 and 9999999
return random.Next(123400, 9999999).ToString();
}
}
