我正在从 .NET 连接到 Web 服务,例如:
var request = (HttpWebRequest) WebRequest.Create(uri);
request.Credentials = new NetworkCredential("usr", "pwd", "domain");
var response = (HttpWebResponse) request.GetResponse();
授权 header 如下所示:
Authorization: Digest username="usr",realm="domain",nonce="...",
uri="/dir",algorithm="MD5",etc...
^^^^^^^^^^
服务器返回 (400) Bad Request。 Chrome 或 IE 发送的 header 如下所示:
Authorization: Digest username="usr", realm="domain", nonce="...",
uri="/dir/query?id=1", algorithm=MD5, etc...
^^^^^^^^^^^^^^^^^^^^^
我们怀疑 URI 的差异导致 Web 服务以 400 错误拒绝请求。是否可以让 HttpRequest 发出包含完整 URI 的授权 header ?
最佳答案
事实证明Digest authentication很容易实现。通过我们自己的实现,我们能够使用完整的 URI(包括参数)来生成 MD5 哈希。这解决了问题。
万一以后有人遇到这个问题,你可以像这样调用解决方法:
var resultText = DigestAuthFixer.GrabResponse("/dir/index.html");
DigestAuthFixer 类的代码:
public static class DigestAuthFixer
{
private static string _host = "http://localhost";
private static string _user = "Mufasa";
private static string _password = "Circle Of Life";
private static string _realm;
private static string _nonce;
private static string _qop;
private static string _cnonce;
private static DateTime _cnonceDate;
private static int _nc;
private static 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 static 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));
}
// http://en.wikipedia.org/wiki/Digest_access_authentication
private static 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 static 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();
}
}
关于c# - HttpWebRequest 在授权 header 中发送无参数 URI,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/3109507/