我正在尝试通过Flickr API对我想要为自己制作的演示应用程序进行身份验证。然后我将使用我将学习Flick API的新功能扩展此应用程序。
所以这只是我想要玩的东西。但是现在我在获取请求令牌方面遇到了一些麻烦。
我在这里关注Flickr身份验证文档：Flickr Authentication
我还发现了这个Mathlabscript：Flickr API with OAuth-based user authentication
基于这些来源，我现在有以下控制台应用程序：
class Program
{
private static string Secret = "2b2b2b2b2b2b2b2b2b";
private static string ConsumerKey = "1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a";
static void Main(string[] args)
{
Random rand = new Random();
string nonce = rand.Next(9999999).ToString();
string timestamp = ((int)(DateTime.UtcNow - new DateTime(1970, 1, 1)).TotalSeconds).ToString();
Console.WriteLine("Nonce: " + nonce);
Console.WriteLine("TimeStamp: " + timestamp);
Console.WriteLine("ConsumerKey: " + ConsumerKey);
Console.WriteLine("AppSecret: " + Secret);
//request url
StringBuilder b = new StringBuilder();
b.Append("http://www.flickr.com/services/oauth/request_token");
b.Append("?");
b.Append("oauth_nonce=");
b.Append(nonce);
b.Append("&oauth_timestamp=");
b.Append(timestamp);
b.Append("&oauth_consumer_key=");
b.Append(ConsumerKey);
b.Append("&oauth_callback=oob");
b.Append("&oauth_signature_method=HMAC-SHA1");
string requesturl = b.ToString();
Console.WriteLine("RequestUrl: " + requesturl);
//base url
string basestring;
StringBuilder bs = new StringBuilder();
bs.Append("GET&");
bs.Append(UrlHelper.Encode("http://www.flickr.com/services/oauth/request_token")+"&");
basestring = bs.ToString();
StringBuilder p = new StringBuilder();
p.Append("oauth_callback=oob");
p.Append("&oauth_consumer_key=");
p.Append(ConsumerKey);
p.Append("oauth_nonce=");
p.Append(nonce);
p.Append("&oauth_signature_method=HMAC-SHA1");
p.Append("&oauth_timestamp=");
p.Append(timestamp);
string paramers = UrlHelper.Encode(p.ToString());
basestring += paramers;
Console.WriteLine("Basestring: " + basestring);
System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
string key = Secret + "&";
Console.WriteLine("Key: " + key);
byte[] keyByte = encoding.GetBytes(key);
//--create message to encrypt
byte[] messageBytes = encoding.GetBytes(basestring);
//--encrypt message using hmac-sha1 with the provided key
HMACSHA1 hmacsha1 = new HMACSHA1(keyByte);
byte[] hashmessage = hmacsha1.ComputeHash(messageBytes);
//--signature
string signature = ByteToString(hashmessage);
Console.WriteLine("Signature: " + signature);
Console.WriteLine("Final Request: " + requesturl + "&oauth_signature=" + signature);
Console.ReadKey(true);
}
public static string ByteToString(byte[] buff)
{
string sbinary = "";
for (int i = 0; i < buff.Length; i++)
{
sbinary += buff[i].ToString("X2"); // hex format
}
return (sbinary);
}
}
当我浏览这个应用程序给我的网址时，我得到以下回复：
oauth_problem=signature_invalid&debug_sbs=GET&http%3A%2F%2Fwww.flickr.com%2Fservices%2Foauth%2Frequest_token&oauth_callback%3Dhttp%253A%252F%252Fwww.google.be%26oauth_consumer_key%3D1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a%26oauth_nonce%3D27504343%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1329469580
我的请求签名似乎无效。
我希望有人可以帮我找到这些请求的正确签名。
我知道有一个FlickNet库已经为大多数开发人员付出了艰苦的努力，但我认为让这个工作也很有用。我查看了FlickrNet的源代码，但没有找到完成此代码的最终安静。
如果你能帮助我，请告诉我。太棒了！
谢谢！
答案 0 :(得分：9)
好的，我终于找到了答案。在签署oauth请求时，您需要记住以下几点。
重要提示：FlickrAPIEndPoint和参数必须是UrlEncoded（分为两部分！） 我使用了一个单独的类进行编码，因为HttpUtility.UrlEncode方法使用小写编码，而应该使用大写编码。
重要提示：参数必须按字母顺序排列！
以下是控制台应用程序的代码，该应用程序将为请求令牌和请求令牌机密创建签名请求。
class Program
{
private static string Secret = "9dcc18a121e9a02e";
private static string ConsumerKey = "3aafc63ec6b05f3f9a9ff3a1c35ce541";
private static string request_token = "";
static void Main(string[] args)
{
string requestString = "http://www.flickr.com/services/oauth/request_token";
//generate a random nonce and a timestamp
Random rand = new Random();
string nonce = rand.Next(999999).ToString();
string timestamp = GetTimestamp();
//create the parameter string in alphabetical order
string parameters = "oauth_callback=" + UrlHelper.Encode("http://www.example.com");
parameters += "&oauth_consumer_key=" + ConsumerKey;
parameters += "&oauth_nonce=" + nonce;
parameters += "&oauth_signature_method=HMAC-SHA1";
parameters += "&oauth_timestamp=" + timestamp;
parameters += "&oauth_version=1.0";
//generate a signature base on the current requeststring and parameters
string signature = generateSignature("GET", requestString, parameters);
//add the parameters and signature to the requeststring
string url = requestString + "?" + parameters + "&oauth_signature=" + signature;
//test the request
WebClient web = new WebClient();
string result = web.DownloadString(url);
Console.WriteLine("Flickr Response: ");
Console.WriteLine(result); //contains the oauth_token and the oauth_token_secret
Console.ReadKey(true);
}
private static string generateSignature(string httpMethod, string ApiEndpoint, string parameters)
{
//url encode the API endpoint and the parameters
//IMPORTANT NOTE:
//encoded text should contain uppercase characters: '=' => %3D !!! (not %3d )
//the HtmlUtility.UrlEncode creates lowercase encoded tags!
//Here I use a urlencode class by Ian Hopkins
string encodedUrl = UrlHelper.Encode(ApiEndpoint);
string encodedParameters = UrlHelper.Encode(parameters);
//generate the basestring
string basestring = httpMethod + "&" + encodedUrl + "&";
parameters = UrlHelper.Encode(parameters);
basestring = basestring + parameters;
//hmac-sha1 encryption:
System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
//create key (request_token can be an empty string)
string key = Secret + "&" + request_token;
byte[] keyByte = encoding.GetBytes(key);
//create message to encrypt
byte[] messageBytes = encoding.GetBytes(basestring);
//encrypt message using hmac-sha1 with the provided key
HMACSHA1 hmacsha1 = new HMACSHA1(keyByte);
byte[] hashmessage = hmacsha1.ComputeHash(messageBytes);
//signature is the base64 format for the genarated hmac-sha1 hash
string signature = System.Convert.ToBase64String(hashmessage);
//encode the signature to make it url safe and return the encoded url
return UrlHelper.Encode(signature);
}
//generator of unix epoch time
public static String GetTimestamp()
{
int epoch = (int)(DateTime.UtcNow - new DateTime(1970, 1, 1)).TotalSeconds;
return epoch.ToString();
}
}
Ian Hopkins的UrlHelper类用于url编码
/// <summary>
/// URL encoding class. Note: use at your own risk.
/// Written by: Ian Hopkins (http://www.lucidhelix.com)
/// Date: 2008-Dec-23
/// (Ported to C# by t3rse (http://www.t3rse.com))
/// </summary>
public class UrlHelper
{
public static string Encode(string str)
{
var charClass = String.Format("0-9a-zA-Z{0}", Regex.Escape("-_.!~*'()"));
return Regex.Replace(str,
String.Format("[^{0}]", charClass),
new MatchEvaluator(EncodeEvaluator));
}
public static string EncodeEvaluator(Match match)
{
return (match.Value == " ") ? "+" : String.Format("%{0:X2}", Convert.ToInt32(match.Value[0]));
}
public static string DecodeEvaluator(Match match)
{
return Convert.ToChar(int.Parse(match.Value.Substring(1), System.Globalization.NumberStyles.HexNumber)).ToString();
}
public static string Decode(string str)
{
return Regex.Replace(str.Replace('+', ' '), "%[0-9a-zA-Z][0-9a-zA-Z]", new MatchEvaluator(DecodeEvaluator));
}
}
答案 1 :(得分：1)
你是从头开始写这个吗？如果是这样，你不应该。请改用http://flickrnet.codeplex.com/。这个图书馆已经为你完成了繁重的工作。