Create HttpAuthController.

net/http/http_auth_controller.cc

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/http/http_auth_controller.h"
+
+#include "base/string_util.h"
+#include "net/base/host_resolver.h"
+#include "net/base/net_util.h"
+#include "net/http/http_auth_handler_factory.h"
+#include "net/http/http_network_session.h"
+#include "net/http/http_request_headers.h"
+#include "net/http/http_request_info.h"
+
+namespace net {
+
+namespace {
+
+// Returns a log message for all the response headers related to the auth
+// challenge.
+std::string AuthChallengeLogMessage(HttpResponseHeaders* headers) {
+  std::string msg;
+  std::string header_val;
+  void* iter = NULL;
+  while (headers->EnumerateHeader(&iter, "proxy-authenticate", &header_val)) {
+    msg.append("\n  Has header Proxy-Authenticate: ");
+    msg.append(header_val);
+  }
+
+  iter = NULL;
+  while (headers->EnumerateHeader(&iter, "www-authenticate", &header_val)) {
+    msg.append("\n  Has header WWW-Authenticate: ");
+    msg.append(header_val);
+  }
+
+  // RFC 4559 requires that a proxy indicate its support of NTLM/Negotiate
+  // authentication with a "Proxy-Support: Session-Based-Authentication"
+  // response header.
+  iter = NULL;
+  while (headers->EnumerateHeader(&iter, "proxy-support", &header_val)) {
+    msg.append("\n  Has header Proxy-Support: ");
+    msg.append(header_val);
+  }
+
+  return msg;
+}
+
+}  // namespace
+
+HttpAuthController::HttpAuthController(
+    HttpAuth::Target target,
+    const GURL& auth_url,
+    scoped_refptr<HttpNetworkSession> session,
+    const BoundNetLog& net_log)
+    : target_(target),
+      auth_url_(auth_url),
+      auth_origin_(auth_url.GetOrigin()),
+      auth_path_(HttpAuth::AUTH_PROXY ? std::string() : auth_url.path()),
+      embedded_identity_used_(false),
+      default_credentials_used_(false),
+      session_(session),
+      net_log_(net_log) {
+}
+
+int HttpAuthController::MaybeGenerateAuthToken(const HttpRequestInfo* request,
+                                               CompletionCallback* callback) {
+  bool needs_auth = HaveAuth() || SelectPreemptiveAuth();
+  if (!needs_auth)
+    return OK;
+  const std::wstring* username = NULL;
+  const std::wstring* password = NULL;
+  if (identity_.source != HttpAuth::IDENT_SRC_DEFAULT_CREDENTIALS) {
+    username = &identity_.username;
+    password = &identity_.password;
+  }
+  DCHECK(auth_token_.empty());
+  return handler_->GenerateAuthToken(username, password, request, callback,
+                                     &auth_token_);
+}
+
+bool HttpAuthController::SelectPreemptiveAuth() {
+  DCHECK(!HaveAuth());
+  DCHECK(identity_.invalid);
+
+  // Don't do preemptive authorization if the URL contains a username/password,
+  // since we must first be challenged in order to use the URL's identity.
+  if (auth_url_.has_username())
+    return false;
+
+  // SelectPreemptiveAuth() is on the critical path for each request, so it
+  // is expected to be fast. LookupByPath() is fast in the common case, since
+  // the number of http auth cache entries is expected to be very small.
+  // (For most users in fact, it will be 0.)
+  HttpAuthCache::Entry* entry = session_->auth_cache()->LookupByPath(
+      auth_origin_, auth_path_);
+  if (!entry)
+    return false;
+
+  // Try to create a handler using the previous auth challenge.
+  scoped_ptr<HttpAuthHandler> handler_preemptive;
+  int rv_create = session_->http_auth_handler_factory()->
+      CreatePreemptiveAuthHandlerFromString(entry->auth_challenge(), target_,
+                                            auth_origin_,
+                                            entry->IncrementNonceCount(),
+                                            net_log_, &handler_preemptive);
+  if (rv_create != OK)
+    return false;
+
+  // Set the state
+  identity_.source = HttpAuth::IDENT_SRC_PATH_LOOKUP;
+  identity_.invalid = false;
+  identity_.username = entry->username();
+  identity_.password = entry->password();
+  handler_.swap(handler_preemptive);
+  return true;
+}
+
+void HttpAuthController::AddAuthorizationHeader(
+    HttpRequestHeaders* authorization_headers) {
+  DCHECK(HaveAuth());
+  DCHECK(!auth_token_.empty());
+  authorization_headers->SetHeader(
+      HttpAuth::GetAuthorizationHeaderName(target_), auth_token_);
+  auth_token_.clear();
+}
+
+int HttpAuthController::HandleAuthChallenge(
+    scoped_refptr<HttpResponseHeaders> headers,
+    int load_flags,
+    bool establishing_tunnel) {
+  DCHECK(headers);
+  DCHECK(auth_origin_.is_valid());
+
+  LOG(INFO) << "The " << HttpAuth::GetAuthTargetString(target_) << " "
+            << auth_origin_ << " requested auth"
+            << AuthChallengeLogMessage(headers.get());
+
+  // The auth we tried just failed, hence it can't be valid. Remove it from
+  // the cache so it won't be used again.
+  // TODO(wtc): IsFinalRound is not the right condition.  In a multi-round
+  // auth sequence, the server may fail the auth in round 1 if our first
+  // authorization header is broken.  We should inspect response_.headers to
+  // determine if the server already failed the auth or wants us to continue.
+  // See http://crbug.com/21015.
+  if (HaveAuth() && handler_->IsFinalRound()) {
+    InvalidateRejectedAuthFromCache();
+    handler_.reset();
+    identity_ = HttpAuth::Identity();
+  }
+
+  identity_.invalid = true;
+
+  if (target_ != HttpAuth::AUTH_SERVER ||
+      !(load_flags & LOAD_DO_NOT_SEND_AUTH_DATA)) {
+    // Find the best authentication challenge that we support.
+    HttpAuth::ChooseBestChallenge(session_->http_auth_handler_factory(),
+                                  headers, target_, auth_origin_, net_log_,
+                                  &handler_);
+  }
+
+  if (!handler_.get()) {
+    if (establishing_tunnel) {
+      LOG(ERROR) << "Can't perform auth to the "
+                 << HttpAuth::GetAuthTargetString(target_) << " "
+                 << auth_origin_ << " when establishing a tunnel"
+                 << AuthChallengeLogMessage(headers.get());
+
+      // We are establishing a tunnel, we can't show the error page because an
+      // active network attacker could control its contents.  Instead, we just
+      // fail to establish the tunnel.
+      DCHECK(target_ == HttpAuth::AUTH_PROXY);
+      return ERR_PROXY_AUTH_REQUESTED;
+    }
+    // We found no supported challenge -- let the transaction continue
+    // so we end up displaying the error page.
+    return OK;
+  }
+
+  if (handler_->NeedsIdentity()) {
+    // Pick a new auth identity to try, by looking to the URL and auth cache.
+    // If an identity to try is found, it is saved to identity_.
+    SelectNextAuthIdentityToTry();
+  } else {
+    // Proceed with the existing identity or a null identity.
+    //
+    // TODO(wtc): Add a safeguard against infinite transaction restarts, if
+    // the server keeps returning "NTLM".
+    identity_.invalid = false;
+  }
+
+  // From this point on, we are restartable.
+
+  if (identity_.invalid) {
+    // We have exhausted all identity possibilities, all we can do now is
+    // pass the challenge information back to the client.
+    PopulateAuthChallenge();
+  }
+
+  // SPN determination (for Negotiate) requires a DNS lookup to find the
+  // canonical name. This needs to be done asynchronously to prevent blocking
+  // the IO thread.
+  if (handler_->NeedsCanonicalName())
+    return ERR_AUTH_NEEDS_CANONICAL_NAME;
+
+  return OK;
+}
+
+int HttpAuthController::ResolveCanonicalName(CompletionCallback* callback) {
+  DCHECK(handler_.get());
+  return handler_->ResolveCanonicalName(session_->host_resolver(), callback);
+}
+
+void HttpAuthController::ResetAuth(const std::wstring& username,
+                                   const std::wstring& password) {
+  DCHECK(identity_.invalid || (username.empty() && password.empty()));
+
+  if (identity_.invalid) {
+    // Update the username/password.
+    identity_.source = HttpAuth::IDENT_SRC_EXTERNAL;
+    identity_.invalid = false;
+    identity_.username = username;
+    identity_.password = password;
+  }
+
+  DCHECK(identity_.source != HttpAuth::IDENT_SRC_PATH_LOOKUP);
+
+  // Add the auth entry to the cache before restarting. We don't know whether
+  // the identity is valid yet, but if it is valid we want other transactions
+  // to know about it. If an entry for (origin, handler->realm()) already
+  // exists, we update it.
+  //
+  // If identity_.source is HttpAuth::IDENT_SRC_NONE or
+  // HttpAuth::IDENT_SRC_DEFAULT_CREDENTIALS, identity_ contains no
+  // identity because identity is not required yet or we're using default
+  // credentials.
+  //
+  // TODO(wtc): For NTLM_SSPI, we add the same auth entry to the cache in
+  // round 1 and round 2, which is redundant but correct.  It would be nice
+  // to add an auth entry to the cache only once, preferrably in round 1.
+  // See http://crbug.com/21015.
+  switch (identity_.source) {
+    case HttpAuth::IDENT_SRC_NONE:
+    case HttpAuth::IDENT_SRC_DEFAULT_CREDENTIALS:
+      break;
+    default:
+      session_->auth_cache()->Add(auth_origin_, handler_->realm(),
+                                  handler_->scheme(), handler_->challenge(),
+                                  identity_.username, identity_.password,
+                                  auth_path_);
+      break;
+  }
+}
+
+void HttpAuthController::InvalidateRejectedAuthFromCache() {
+  DCHECK(HaveAuth());
+
+  // TODO(eroman): this short-circuit can be relaxed. If the realm of
+  // the preemptively used auth entry matches the realm of the subsequent
+  // challenge, then we can invalidate the preemptively used entry.
+  // Otherwise as-is we may send the failed credentials one extra time.
+  if (identity_.source == HttpAuth::IDENT_SRC_PATH_LOOKUP)
+    return;
+
+  // Clear the cache entry for the identity we just failed on.
+  // Note: we require the username/password to match before invalidating
+  // since the entry in the cache may be newer than what we used last time.
+  session_->auth_cache()->Remove(auth_origin_, handler_->realm(),
+                                 handler_->scheme(), identity_.username,
+                                 identity_.password);
+}
+
+bool HttpAuthController::SelectNextAuthIdentityToTry() {
+  DCHECK(handler_.get());
+  DCHECK(identity_.invalid);
+
+  // Try to use the username/password encoded into the URL first.
+  if (target_ == HttpAuth::AUTH_SERVER && auth_url_.has_username() &&
+      !embedded_identity_used_) {
+    identity_.source = HttpAuth::IDENT_SRC_URL;
+    identity_.invalid = false;
+    // Extract the username:password from the URL.
+    GetIdentityFromURL(auth_url_,
+                       &identity_.username,
+                       &identity_.password);
+    embedded_identity_used_ = true;
+    // TODO(eroman): If the password is blank, should we also try combining
+    // with a password from the cache?
+    return true;
+  }
+
+  // Check the auth cache for a realm entry.
+  HttpAuthCache::Entry* entry =
+    session_->auth_cache()->Lookup(auth_origin_, handler_->realm(),
+                                   handler_->scheme());
+
+  if (entry) {
+    identity_.source = HttpAuth::IDENT_SRC_REALM_LOOKUP;
+    identity_.invalid = false;
+    identity_.username = entry->username();
+    identity_.password = entry->password();
+    return true;
+  }
+
+  // Use default credentials (single sign on) if this is the first attempt
+  // at identity.  Do not allow multiple times as it will infinite loop.
+  // We use default credentials after checking the auth cache so that if
+  // single sign-on doesn't work, we won't try default credentials for future
+  // transactions.
+  if (!default_credentials_used_ && handler_->AllowsDefaultCredentials()) {
+    identity_.source = HttpAuth::IDENT_SRC_DEFAULT_CREDENTIALS;
+    identity_.invalid = false;
+    default_credentials_used_ = true;
+    return true;
+  }
+
+  return false;
+}
+
+void HttpAuthController::PopulateAuthChallenge() {
+  // Populates response_.auth_challenge with the authentication challenge info.
+  // This info is consumed by URLRequestHttpJob::GetAuthChallengeInfo().
+
+  auth_info_ = new AuthChallengeInfo;
+  auth_info_->is_proxy = target_ == HttpAuth::AUTH_PROXY;
+  auth_info_->host_and_port = ASCIIToWide(GetHostAndPort(auth_origin_));
+  auth_info_->scheme = ASCIIToWide(handler_->scheme());
+  // TODO(eroman): decode realm according to RFC 2047.
+  auth_info_->realm = ASCIIToWide(handler_->realm());
+}
+
+}  // namespace net