如何使用HttpWebRequest进行摘要式身份validation?

我发现的各种文章( 1,2 )使这看起来很容易:

WebRequest request = HttpWebRequest.Create(url); var credentialCache = new CredentialCache(); credentialCache.Add( new Uri(url), // request url "Digest", // authentication type new NetworkCredential("user", "password") // credentials ); request.Credentials = credentialCache; 

但是,这仅适用于没有URL参数的URL。 例如,我可以下载http://example.com/test/xyz.html ,但是当我尝试下载http://example.com/test?page=xyz ,结果是400 Bad Request消息在服务器的日志中运行以下内容(运行Apache 2.2):

 Digest: uri mismatch -  does not match request-uri  

我的第一个想法是摘要规范要求从摘要哈希中删除URL参数 – 但是从传递给credentialCache.Add()的URL中删除参数并没有改变。 所以它必须是相反的方式,在.NET框架中的某个地方错误地从URL中删除参数。

你说你删除了查询字符串参数,但你是否尝试一直回到主机? 我见过的每个CredentialsCache.Add()的例子似乎只使用主机,而CredentialsCache.Add()的文档将Uri参数列为“uriPrefix”,这似乎在说明。

换句话说,试试这个:

 Uri uri = new Uri(url); WebRequest request = WebRequest.Create(uri); var credentialCache = new CredentialCache(); credentialCache.Add( new Uri(uri.GetLeftPart(UriPartial.Authority)), // request url's host "Digest", // authentication type new NetworkCredential("user", "password") // credentials ); request.Credentials = credentialCache; 

如果这样做,您还必须确保不会多次向缓存添加相同的“权限”…对同一主机的所有请求都应该能够使用相同的凭据缓存条目。

从这篇文章中获取的代码对我来说非常有效,可以通过C#中的HttpWebRequest实现摘要式身份validation

我有以下问题,当我在浏览器中浏览源URL时它要求用户名和密码并且工作正常,但是上面的任何代码示例都没有工作,检查请求/响应头(在Firefox中的Web开发人员工具中)我可以看到具有类型摘要授权的标题。

第1步添加:

 using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Security.Cryptography; using System.Text.RegularExpressions; using System.Net; using System.IO; namespace NUI { public class DigestAuthFixer { private static string _host; private static string _user; private static string _password; private static string _realm; private static string _nonce; private static string _qop; private static string _cnonce; private static DateTime _cnonceDate; private static int _nc; public DigestAuthFixer(string host, string user, string password) { // TODO: Complete member initialization _host = host; _user = user; _password = password; } private string CalculateMd5Hash( string input) { var inputBytes = Encoding.ASCII.GetBytes(input); var hash = MD5.Create().ComputeHash(inputBytes); var sb = new StringBuilder(); foreach (var b in hash) sb.Append(b.ToString("x2")); return sb.ToString(); } private string GrabHeaderVar( string varName, string header) { var regHeader = new Regex(string.Format(@"{0}=""([^""]*)""", varName)); var matchHeader = regHeader.Match(header); if (matchHeader.Success) return matchHeader.Groups[1].Value; throw new ApplicationException(string.Format("Header {0} not found", varName)); } private string GetDigestHeader( string dir) { _nc = _nc + 1; var ha1 = CalculateMd5Hash(string.Format("{0}:{1}:{2}", _user, _realm, _password)); var ha2 = CalculateMd5Hash(string.Format("{0}:{1}", "GET", dir)); var digestResponse = CalculateMd5Hash(string.Format("{0}:{1}:{2:00000000}:{3}:{4}:{5}", ha1, _nonce, _nc, _cnonce, _qop, ha2)); return string.Format("Digest username=\"{0}\", realm=\"{1}\", nonce=\"{2}\", uri=\"{3}\", " + "algorithm=MD5, response=\"{4}\", qop={5}, nc={6:00000000}, cnonce=\"{7}\"", _user, _realm, _nonce, dir, digestResponse, _qop, _nc, _cnonce); } public string GrabResponse( string dir) { var url = _host + dir; var uri = new Uri(url); var request = (HttpWebRequest)WebRequest.Create(uri); // If we've got a recent Auth header, re-use it! if (!string.IsNullOrEmpty(_cnonce) && DateTime.Now.Subtract(_cnonceDate).TotalHours < 1.0) { request.Headers.Add("Authorization", GetDigestHeader(dir)); } HttpWebResponse response; try { response = (HttpWebResponse)request.GetResponse(); } catch (WebException ex) { // Try to fix a 401 exception by adding a Authorization header if (ex.Response == null || ((HttpWebResponse)ex.Response).StatusCode != HttpStatusCode.Unauthorized) throw; var wwwAuthenticateHeader = ex.Response.Headers["WWW-Authenticate"]; _realm = GrabHeaderVar("realm", wwwAuthenticateHeader); _nonce = GrabHeaderVar("nonce", wwwAuthenticateHeader); _qop = GrabHeaderVar("qop", wwwAuthenticateHeader); _nc = 0; _cnonce = new Random().Next(123400, 9999999).ToString(); _cnonceDate = DateTime.Now; var request2 = (HttpWebRequest)WebRequest.Create(uri); request2.Headers.Add("Authorization", GetDigestHeader(dir)); response = (HttpWebResponse)request2.GetResponse(); } var reader = new StreamReader(response.GetResponseStream()); return reader.ReadToEnd(); } } 

}

第2步:调用新方法

 DigestAuthFixer digest = new DigestAuthFixer(domain, username, password); string strReturn = digest.GrabResponse(dir); 

如果url是: http : //xyz.rss.com/folder/rss然后域名: http : //xyz.rss.com (域名部分)目录:/文件夹/ rss(url的其余部分)

您也可以将其作为流返回并使用XmlDocument Load()方法。

解决方案是在apache中激活此参数:

  BrowserMatch "MSIE" AuthDigestEnableQueryStringHack=On 

更多信息: http : //httpd.apache.org/docs/2.0/mod/mod_auth_digest.html#msie

然后在webrequest对象的代码中添加此属性:

  request.UserAgent = "MSIE" 

它对我很有用

我认为第二个URL指向动态页面,您应首先使用GET调用它来获取HTML然后下载它。 虽然没有这方面的经验。