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//------------------------------------------------------------------------------
// <copyright file="_AuthenticationState.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Net {
using System.Collections;
using System.IO;
using System.Runtime.Serialization;
using System.Security;
using System.Security.Authentication.ExtendedProtection;
using System.Security.Cryptography.X509Certificates;
using System.Security.Permissions;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Globalization;
using System.Net.Security;
/// <devdoc>
/// <para>Used by HttpWebRequest to syncronize and orchestrate authentication<para>
/// </devdoc>
internal class AuthenticationState {
// true if we already attempted pre-authentication regardless if it has been
// 1) possible,
// 2) succesfull or
// 3) unsuccessfull
private bool TriedPreAuth;
internal Authorization Authorization;
internal IAuthenticationModule Module;
// used to request a special connection for NTLM
internal string UniqueGroupId;
// used to distinguish proxy auth from server auth
private bool IsProxyAuth;
// the Uri of the host we're authenticating (proxy/server)
// used to match entries in the CredentialCache
internal Uri ChallengedUri;
private SpnToken ChallengedSpn;
#if !FEATURE_PAL
// this is the client's security context for SSPI based authentication
// pared with the authentication module that set it.
private NTAuthentication SecurityContext;
internal NTAuthentication GetSecurityContext(IAuthenticationModule module) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::GetSecurityContext(" + module.AuthenticationType + ") returning NTAuthentication#" + ValidationHelper.HashString((object)module==(object)Module ? SecurityContext : null));
return (object)module==(object)Module ? SecurityContext : null;
}
internal void SetSecurityContext(NTAuthentication securityContext, IAuthenticationModule module) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::SetSecurityContext(" + module.AuthenticationType + ") was NTAuthentication#" + ValidationHelper.HashString(SecurityContext) + " now NTAuthentication#" + ValidationHelper.HashString(securityContext));
SecurityContext = securityContext;
}
#endif // !FEATURE_PAL
private TransportContext _TransportContext;
internal TransportContext TransportContext
{
get { return _TransportContext; }
set { _TransportContext = value; }
}
internal HttpResponseHeader AuthenticateHeader {
get {
return IsProxyAuth ? HttpResponseHeader.ProxyAuthenticate : HttpResponseHeader.WwwAuthenticate;
}
}
internal string AuthorizationHeader {
get {
return IsProxyAuth ? HttpKnownHeaderNames.ProxyAuthorization : HttpKnownHeaderNames.Authorization;
}
}
internal HttpStatusCode StatusCodeMatch {
get {
return IsProxyAuth ? HttpStatusCode.ProxyAuthenticationRequired : HttpStatusCode.Unauthorized;
}
}
internal AuthenticationState(bool isProxyAuth) {
IsProxyAuth = isProxyAuth;
}
//
// we need to do this to handle proxies in the correct way before
// calling into the AuthenticationManager APIs
//
private void PrepareState(HttpWebRequest httpWebRequest)
{
Uri newUri = IsProxyAuth ? httpWebRequest.ServicePoint.InternalAddress : httpWebRequest.GetRemoteResourceUri();
if ((object)ChallengedUri != (object)newUri)
{
if ((object)ChallengedUri == null || (object)ChallengedUri.Scheme != (object)newUri.Scheme || ChallengedUri.Host != newUri.Host || ChallengedUri.Port != newUri.Port)
{
//
// must be a new server/port/scheme for this auth state, can happen on a redirect
//
ChallengedSpn = null;
}
ChallengedUri = newUri;
}
httpWebRequest.CurrentAuthenticationState = this;
}
//
//
//
internal SpnToken GetComputeSpn(HttpWebRequest httpWebRequest)
{
if (ChallengedSpn != null)
return ChallengedSpn;
bool trustNewHost = true; // Assume trusted unless proven otherwise
string spnKey = httpWebRequest.ChallengedUri.GetParts(UriComponents.Scheme | UriComponents.Host | UriComponents.Port | UriComponents.Path, UriFormat.SafeUnescaped);
SpnToken spnToken = AuthenticationManager.SpnDictionary.InternalGet(spnKey);
if (spnToken == null || spnToken.Spn == null)
{
string host;
if (!IsProxyAuth && (httpWebRequest.ServicePoint.InternalProxyServicePoint || httpWebRequest.UseCustomHost))
{
// Here the NT-Security folks need us to attempt a DNS lookup to figure out
// the FQDN. only do the lookup for short names (no IP addresses or DNS names)
//
// Initialize a backup value
host = httpWebRequest.ChallengedUri.Host;
// This host comes from the request/user, assume Trusted unless proven otherwise.
if (httpWebRequest.ChallengedUri.HostNameType != UriHostNameType.IPv6
&& httpWebRequest.ChallengedUri.HostNameType != UriHostNameType.IPv4
&& host.IndexOf('.') == -1)
{
try {
//
IPHostEntry result;
if (Dns.TryInternalResolve(host, out result))
{
host = result.HostName;
trustNewHost &= result.isTrustedHost; // Can only lose trust
}
}
catch (Exception exception) {
if (NclUtilities.IsFatal(exception)) throw;
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::GetComputeSpn() GetHostByName(host) failed:" + ValidationHelper.ToString(exception));
}
}
}
else
{
// For this cases we already did a DNS lookup
//
host = httpWebRequest.ServicePoint.Hostname;
trustNewHost &= httpWebRequest.ServicePoint.IsTrustedHost; // Can only lose trust
}
string spn = "HTTP/" + host;
spnKey = httpWebRequest.ChallengedUri.GetParts(UriComponents.SchemeAndServer, UriFormat.SafeUnescaped) + "/";
spnToken = new SpnToken(spn, trustNewHost);
AuthenticationManager.SpnDictionary.InternalSet(spnKey, spnToken);
}
ChallengedSpn = spnToken;
return ChallengedSpn;
}
//
internal void PreAuthIfNeeded(HttpWebRequest httpWebRequest, ICredentials authInfo) {
//
// attempt to do preauth, if needed
//
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::PreAuthIfNeeded() TriedPreAuth:" + TriedPreAuth.ToString() + " authInfo:" + ValidationHelper.HashString(authInfo));
if (!TriedPreAuth) {
TriedPreAuth = true;
if (authInfo!=null) {
PrepareState(httpWebRequest);
Authorization preauth = null;
try {
preauth = AuthenticationManager.PreAuthenticate(httpWebRequest, authInfo);
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::PreAuthIfNeeded() preauth:" + ValidationHelper.HashString(preauth));
if (preauth!=null && preauth.Message!=null) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::PreAuthIfNeeded() setting TriedPreAuth to Complete:" + preauth.Complete.ToString());
UniqueGroupId = preauth.ConnectionGroupId;
httpWebRequest.Headers.Set(AuthorizationHeader, preauth.Message);
}
}
catch (Exception exception) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::PreAuthIfNeeded() PreAuthenticate() returned exception:" + exception.Message);
ClearSession(httpWebRequest);
}
}
}
}
//
// attempts to authenticate the request:
// returns true only if it succesfully called into the AuthenticationManager
// and got back a valid Authorization and succesfully set the appropriate auth headers
//
internal bool AttemptAuthenticate(HttpWebRequest httpWebRequest, ICredentials authInfo) {
//
// Check for previous authentication attempts or the presence of credentials
//
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() httpWebRequest#" + ValidationHelper.HashString(httpWebRequest) + " AuthorizationHeader:" + AuthorizationHeader.ToString());
if (Authorization!=null && Authorization.Complete) {
//
// here the design gets "dirty".
// if this is proxy auth, we might have been challenged by an external
// server as well. in this case we will have to clear our previous proxy
// auth state before we go any further. this will be broken if the handshake
// requires more than one dropped connection (which NTLM is a border case for,
// since it droppes the connection on the 1st challenge but not on the second)
//
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() Authorization!=null Authorization.Complete:" + Authorization.Complete.ToString());
if (IsProxyAuth) {
//
// so, we got passed a 407 but now we got a 401, the proxy probably
// dropped the connection on us so we need to reset our proxy handshake
// Consider: this should have been taken care by Update()
//
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() ProxyAuth cleaning up auth status");
ClearAuthReq(httpWebRequest);
}
return false;
}
if (authInfo==null) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() authInfo==null Authorization#" + ValidationHelper.HashString(Authorization));
return false;
}
string challenge = httpWebRequest.AuthHeader(AuthenticateHeader);
if (challenge==null) {
//
// the server sent no challenge, but this might be the case
// in which we're succeeding an authorization handshake to
// a proxy while a handshake with the server is still in progress.
// if the handshake with the proxy is complete and we actually have
// a handshake with the server in progress we can send the authorization header for the server as well.
//
if (!IsProxyAuth && Authorization!=null && httpWebRequest.ProxyAuthenticationState.Authorization!=null) {
httpWebRequest.Headers.Set(AuthorizationHeader, Authorization.Message);
}
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() challenge==null Authorization#" + ValidationHelper.HashString(Authorization));
return false;
}
//
// if the AuthenticationManager throws on Authenticate,
// bubble up that Exception to the user
//
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() challenge:" + challenge);
PrepareState(httpWebRequest);
try {
Authorization = AuthenticationManager.Authenticate(challenge, httpWebRequest, authInfo);
}
catch (Exception exception) {
Authorization = null;
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::PreAuthIfNeeded() PreAuthenticate() returned exception:" + exception.Message);
ClearSession(httpWebRequest);
throw;
}
if (Authorization==null) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() Authorization==null");
return false;
}
if (Authorization.Message==null) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() Authorization.Message==null");
Authorization = null;
return false;
}
UniqueGroupId = Authorization.ConnectionGroupId;
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::AttemptAuthenticate() AuthorizationHeader:" + AuthorizationHeader + " blob: " + Authorization.Message.Length + "bytes Complete:" + Authorization.Complete.ToString());
try {
//
// a "bad" module could try sending bad characters in the HTTP headers.
// catch the exception from WebHeaderCollection.CheckBadChars()
// fail the auth process
// and return the exception to the user as InnerException
//
httpWebRequest.Headers.Set(AuthorizationHeader, Authorization.Message);
}
catch {
Authorization = null;
ClearSession(httpWebRequest);
throw;
}
return true;
}
internal void ClearAuthReq(HttpWebRequest httpWebRequest) {
//
// if we are authenticating and we're being redirected to
// another authentication space then remove the current
// authentication header
//
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::ClearAuthReq() httpWebRequest#" + ValidationHelper.HashString(httpWebRequest) + " " + AuthorizationHeader.ToString() + ": " + ValidationHelper.ToString(httpWebRequest.Headers[AuthorizationHeader]));
TriedPreAuth = false;
Authorization = null;
UniqueGroupId = null;
httpWebRequest.Headers.Remove(AuthorizationHeader);
}
//
// gives the IAuthenticationModule a chance to update its internal state.
// do any necessary cleanup and update the Complete status of the associated Authorization.
//
internal void Update(HttpWebRequest httpWebRequest) {
//
// RAID#86753
// Microsoft: this is just a fix for redirection & kerberos.
// we need to close the Context and call ISC() again with the final
// blob returned from the server. to do this in general
// we would probably need to change the IAuthenticationMdule interface and
// add this Update() method. for now we just have it internally.
//
// actually this turns out to be quite handy for 2 more cases:
// NTLM auth: we need to clear the connection group after we suceed to prevent leakage.
// Digest auth: we need to support stale credentials, if we fail with a 401 and stale is true we need to retry.
//
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::Update() httpWebRequest#" + ValidationHelper.HashString(httpWebRequest) + " Authorization#" + ValidationHelper.HashString(Authorization) + " ResponseStatusCode:" + httpWebRequest.ResponseStatusCode.ToString());
if (Authorization!=null) {
PrepareState(httpWebRequest);
ISessionAuthenticationModule myModule = Module as ISessionAuthenticationModule;
if (myModule!=null) {
//
// the whole point here is to complete the Security Context. Sometimes, though,
// a bad cgi script or a bad server, could miss sending back the final blob.
// in this case we won't be able to complete the handshake, but we'll have to clean up anyway.
//
string challenge = httpWebRequest.AuthHeader(AuthenticateHeader);
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::Update() Complete:" + Authorization.Complete.ToString() + " Module:" + ValidationHelper.ToString(Module) + " challenge:" + ValidationHelper.ToString(challenge));
if (!IsProxyAuth && httpWebRequest.ResponseStatusCode==HttpStatusCode.ProxyAuthenticationRequired) {
//
// don't call Update on the module, since there's an ongoing
// handshake and we don't need to update any state in such a case
//
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::Update() skipping call to " + myModule.ToString() + ".Update() since we need to reauthenticate with the proxy");
}
else {
bool complete = true;
try {
complete = myModule.Update(challenge, httpWebRequest);
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::Update() " + myModule.ToString() + ".Update() returned complete:" + complete.ToString());
}
catch (Exception exception) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::Update() " + myModule.ToString() + ".Update() caught exception:" + exception.Message);
ClearSession(httpWebRequest);
#if !FEATURE_PAL
if ((httpWebRequest.AuthenticationLevel == AuthenticationLevel.MutualAuthRequired) &&
(httpWebRequest.CurrentAuthenticationState == null || httpWebRequest.CurrentAuthenticationState.Authorization == null || !httpWebRequest.CurrentAuthenticationState.Authorization.MutuallyAuthenticated))
{
throw;
}
#endif // !FEATURE_PAL
}
Authorization.SetComplete(complete);
}
}
//
// If authentication was successful, create binding between
// the request and the authorization for future preauthentication
//
if (httpWebRequest.PreAuthenticate && Module != null && Authorization.Complete && Module.CanPreAuthenticate && httpWebRequest.ResponseStatusCode != StatusCodeMatch) {
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::Update() handshake is Complete calling BindModule()");
AuthenticationManager.BindModule(ChallengedUri, Authorization, Module);
}
}
}
internal void ClearSession() {
#if !FEATURE_PAL // Security
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::ClearSession() NTAuthentication#" + ValidationHelper.HashString(SecurityContext));
if (SecurityContext!=null) {
SecurityContext.CloseContext();
SecurityContext = null;
}
#endif // FEATURE_PAL // Security
}
internal void ClearSession(HttpWebRequest httpWebRequest) {
PrepareState(httpWebRequest);
ISessionAuthenticationModule myModule = Module as ISessionAuthenticationModule;
Module = null;
if (myModule!=null) {
try {
myModule.ClearSession(httpWebRequest);
}
catch (Exception exception) {
if (NclUtilities.IsFatal(exception)) throw;
GlobalLog.Print("AuthenticationState#" + ValidationHelper.HashString(this) + "::ClearSession() " + myModule.ToString() + ".Update() caught exception:" + exception.Message);
}
}
}
}
}
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