net/http/http_auth_cache.cc - chromium/src - Git at Google

 // Copyright (c) 2011 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_cache.h"

 #include "base/logging.h"
 #include "base/strings/string_util.h"

 namespace {

 // Helper to find the containing directory of path. In RFC 2617 this is what
 // they call the "last symbolic element in the absolute path".
 // Examples:
 //   "/foo/bar.txt" --> "/foo/"
 //   "/foo/" --> "/foo/"
 std::string GetParentDirectory(const std::string& path) {
   std::string::size_type last_slash = path.rfind("/");
   if (last_slash == std::string::npos) {
     // No slash (absolute paths always start with slash, so this must be
     // the proxy case which uses empty string).
     DCHECK(path.empty());
     return path;
   }
   return path.substr(0, last_slash + 1);
 }

 // Debug helper to check that |path| arguments are properly formed.
 // (should be absolute path, or empty string).
 void CheckPathIsValid(const std::string& path) {
   DCHECK(path.empty() || path[0] == '/');
 }

 // Return true if |path| is a subpath of |container|. In other words, is
 // |container| an ancestor of |path|?
 bool IsEnclosingPath(const std::string& container, const std::string& path) {
   DCHECK(container.empty() || *(container.end() - 1) == '/');
   return ((container.empty() && path.empty()) ||
           (!container.empty() && StartsWithASCII(path, container, true)));
 }

 // Debug helper to check that |origin| arguments are properly formed.
 void CheckOriginIsValid(const GURL& origin) {
   DCHECK(origin.is_valid());
   // Note that the scheme may be FTP when we're using a HTTP proxy.
   DCHECK(origin.SchemeIs("http") || origin.SchemeIs("https") ||
          origin.SchemeIs("ftp"));
   DCHECK(origin.GetOrigin() == origin);
 }

 // Functor used by remove_if.
 struct IsEnclosedBy {
   explicit IsEnclosedBy(const std::string& path) : path(path) { }
   bool operator() (const std::string& x) const {
     return IsEnclosingPath(path, x);
   }
   const std::string& path;
 };

 }  // namespace

 namespace net {

 HttpAuthCache::HttpAuthCache() {
 }

 HttpAuthCache::~HttpAuthCache() {
 }

 // Performance: O(n), where n is the number of realm entries.
 HttpAuthCache::Entry* HttpAuthCache::Lookup(const GURL& origin,
                                             const std::string& realm,
                                             HttpAuth::Scheme scheme) {
   CheckOriginIsValid(origin);

   // Linear scan through the realm entries.
   for (EntryList::iterator it = entries_.begin(); it != entries_.end(); ++it) {
     if (it->origin() == origin && it->realm() == realm &&
         it->scheme() == scheme)
       return &(*it);
   }
   return NULL;  // No realm entry found.
 }

 // Performance: O(n*m), where n is the number of realm entries, m is the number
 // of path entries per realm. Both n amd m are expected to be small; m is
 // kept small because AddPath() only keeps the shallowest entry.
 HttpAuthCache::Entry* HttpAuthCache::LookupByPath(const GURL& origin,
                                                   const std::string& path) {
   HttpAuthCache::Entry* best_match = NULL;
   size_t best_match_length = 0;
   CheckOriginIsValid(origin);
   CheckPathIsValid(path);

   // RFC 2617 section 2:
   // A client SHOULD assume that all paths at or deeper than the depth of
   // the last symbolic element in the path field of the Request-URI also are
   // within the protection space ...
   std::string parent_dir = GetParentDirectory(path);

   // Linear scan through the realm entries.
   for (EntryList::iterator it = entries_.begin(); it != entries_.end(); ++it) {
     size_t len = 0;
     if (it->origin() == origin && it->HasEnclosingPath(parent_dir, &len) &&
         (!best_match || len > best_match_length)) {
       best_match_length = len;
       best_match = &(*it);
     }
   }
   return best_match;
 }

 HttpAuthCache::Entry* HttpAuthCache::Add(const GURL& origin,
                                          const std::string& realm,
                                          HttpAuth::Scheme scheme,
                                          const std::string& auth_challenge,
                                          const AuthCredentials& credentials,
                                          const std::string& path) {
   CheckOriginIsValid(origin);
   CheckPathIsValid(path);

   // Check for existing entry (we will re-use it if present).
   HttpAuthCache::Entry* entry = Lookup(origin, realm, scheme);
   if (!entry) {
     // Failsafe to prevent unbounded memory growth of the cache.
     if (entries_.size() >= kMaxNumRealmEntries) {
       LOG(WARNING) << "Num auth cache entries reached limit -- evicting";
       entries_.pop_back();
     }

     entries_.push_front(Entry());
     entry = &entries_.front();
     entry->origin_ = origin;
     entry->realm_ = realm;
     entry->scheme_ = scheme;
   }
   DCHECK_EQ(origin, entry->origin_);
   DCHECK_EQ(realm, entry->realm_);
   DCHECK_EQ(scheme, entry->scheme_);

   entry->auth_challenge_ = auth_challenge;
   entry->credentials_ = credentials;
   entry->nonce_count_ = 1;
   entry->AddPath(path);

   return entry;
 }

 HttpAuthCache::Entry::~Entry() {
 }

 void HttpAuthCache::Entry::UpdateStaleChallenge(
     const std::string& auth_challenge) {
   auth_challenge_ = auth_challenge;
   nonce_count_ = 1;
 }

 HttpAuthCache::Entry::Entry()
     : scheme_(HttpAuth::AUTH_SCHEME_MAX),
       nonce_count_(0) {
 }

 void HttpAuthCache::Entry::AddPath(const std::string& path) {
   std::string parent_dir = GetParentDirectory(path);
   if (!HasEnclosingPath(parent_dir, NULL)) {
     // Remove any entries that have been subsumed by the new entry.
     paths_.remove_if(IsEnclosedBy(parent_dir));

     // Failsafe to prevent unbounded memory growth of the cache.
     if (paths_.size() >= kMaxNumPathsPerRealmEntry) {
       LOG(WARNING) << "Num path entries for " << origin()
                    << " has grown too large -- evicting";
       paths_.pop_back();
     }

     // Add new path.
     paths_.push_front(parent_dir);
   }
 }

 bool HttpAuthCache::Entry::HasEnclosingPath(const std::string& dir,
                                             size_t* path_len) {
   DCHECK(GetParentDirectory(dir) == dir);
   for (PathList::const_iterator it = paths_.begin(); it != paths_.end();
        ++it) {
     if (IsEnclosingPath(*it, dir)) {
       // No element of paths_ may enclose any other element.
       // Therefore this path is the tightest bound.  Important because
       // the length returned is used to determine the cache entry that
       // has the closest enclosing path in LookupByPath().
       if (path_len)
         *path_len = it->length();
       return true;
     }
   }
   return false;
 }

 bool HttpAuthCache::Remove(const GURL& origin,
                            const std::string& realm,
                            HttpAuth::Scheme scheme,
                            const AuthCredentials& credentials) {
   for (EntryList::iterator it = entries_.begin(); it != entries_.end(); ++it) {
     if (it->origin() == origin && it->realm() == realm &&
         it->scheme() == scheme) {
       if (credentials.Equals(it->credentials())) {
         entries_.erase(it);
         return true;
       }
       return false;
     }
   }
   return false;
 }

 bool HttpAuthCache::UpdateStaleChallenge(const GURL& origin,
                                          const std::string& realm,
                                          HttpAuth::Scheme scheme,
                                          const std::string& auth_challenge) {
   HttpAuthCache::Entry* entry = Lookup(origin, realm, scheme);
   if (!entry)
     return false;
   entry->UpdateStaleChallenge(auth_challenge);
   return true;
 }

 void HttpAuthCache::UpdateAllFrom(const HttpAuthCache& other) {
   for (EntryList::const_iterator it = other.entries_.begin();
        it != other.entries_.end(); ++it) {
     // Add an Entry with one of the original entry's paths.
     DCHECK(it->paths_.size() > 0);
     Entry* entry = Add(it->origin(), it->realm(), it->scheme(),
                        it->auth_challenge(), it->credentials(),
                        it->paths_.back());
     // Copy all other paths.
     for (Entry::PathList::const_reverse_iterator it2 = ++it->paths_.rbegin();
          it2 != it->paths_.rend(); ++it2)
       entry->AddPath(*it2);
     // Copy nonce count (for digest authentication).
     entry->nonce_count_ = it->nonce_count_;
   }
 }

 }  // namespace net
	// Copyright (c) 2011 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_cache.h"

	#include "base/logging.h"
	#include "base/strings/string_util.h"

	namespace {

	// Helper to find the containing directory of path. In RFC 2617 this is what
	// they call the "last symbolic element in the absolute path".
	// Examples:
	// "/foo/bar.txt" --> "/foo/"
	// "/foo/" --> "/foo/"
	std::string GetParentDirectory(const std::string& path) {
	std::string::size_type last_slash = path.rfind("/");
	if (last_slash == std::string::npos) {
	// No slash (absolute paths always start with slash, so this must be
	// the proxy case which uses empty string).
	DCHECK(path.empty());
	return path;
	}
	return path.substr(0, last_slash + 1);
	}

	// Debug helper to check that \|path\| arguments are properly formed.
	// (should be absolute path, or empty string).
	void CheckPathIsValid(const std::string& path) {
	DCHECK(path.empty() \|\| path[0] == '/');
	}

	// Return true if \|path\| is a subpath of \|container\|. In other words, is
	// \|container\| an ancestor of \|path\|?
	bool IsEnclosingPath(const std::string& container, const std::string& path) {
	DCHECK(container.empty() \|\| *(container.end() - 1) == '/');
	return ((container.empty() && path.empty()) \|\|
	(!container.empty() && StartsWithASCII(path, container, true)));
	}

	// Debug helper to check that \|origin\| arguments are properly formed.
	void CheckOriginIsValid(const GURL& origin) {
	DCHECK(origin.is_valid());
	// Note that the scheme may be FTP when we're using a HTTP proxy.
	DCHECK(origin.SchemeIs("http") \|\| origin.SchemeIs("https") \|\|
	origin.SchemeIs("ftp"));
	DCHECK(origin.GetOrigin() == origin);
	}

	// Functor used by remove_if.
	struct IsEnclosedBy {
	explicit IsEnclosedBy(const std::string& path) : path(path) { }
	bool operator() (const std::string& x) const {
	return IsEnclosingPath(path, x);
	}
	const std::string& path;
	};

	} // namespace

	namespace net {

	HttpAuthCache::HttpAuthCache() {
	}

	HttpAuthCache::~HttpAuthCache() {
	}

	// Performance: O(n), where n is the number of realm entries.
	HttpAuthCache::Entry* HttpAuthCache::Lookup(const GURL& origin,
	const std::string& realm,
	HttpAuth::Scheme scheme) {
	CheckOriginIsValid(origin);

	// Linear scan through the realm entries.
	for (EntryList::iterator it = entries_.begin(); it != entries_.end(); ++it) {
	if (it->origin() == origin && it->realm() == realm &&
	it->scheme() == scheme)
	return &(*it);
	}
	return NULL; // No realm entry found.
	}

	// Performance: O(n*m), where n is the number of realm entries, m is the number
	// of path entries per realm. Both n amd m are expected to be small; m is
	// kept small because AddPath() only keeps the shallowest entry.
	HttpAuthCache::Entry* HttpAuthCache::LookupByPath(const GURL& origin,
	const std::string& path) {
	HttpAuthCache::Entry* best_match = NULL;
	size_t best_match_length = 0;
	CheckOriginIsValid(origin);
	CheckPathIsValid(path);

	// RFC 2617 section 2:
	// A client SHOULD assume that all paths at or deeper than the depth of
	// the last symbolic element in the path field of the Request-URI also are
	// within the protection space ...
	std::string parent_dir = GetParentDirectory(path);

	// Linear scan through the realm entries.
	for (EntryList::iterator it = entries_.begin(); it != entries_.end(); ++it) {
	size_t len = 0;
	if (it->origin() == origin && it->HasEnclosingPath(parent_dir, &len) &&
	(!best_match \|\| len > best_match_length)) {
	best_match_length = len;
	best_match = &(*it);
	}
	}
	return best_match;
	}

	HttpAuthCache::Entry* HttpAuthCache::Add(const GURL& origin,
	const std::string& realm,
	HttpAuth::Scheme scheme,
	const std::string& auth_challenge,
	const AuthCredentials& credentials,
	const std::string& path) {
	CheckOriginIsValid(origin);
	CheckPathIsValid(path);

	// Check for existing entry (we will re-use it if present).
	HttpAuthCache::Entry* entry = Lookup(origin, realm, scheme);
	if (!entry) {
	// Failsafe to prevent unbounded memory growth of the cache.
	if (entries_.size() >= kMaxNumRealmEntries) {
	LOG(WARNING) << "Num auth cache entries reached limit -- evicting";
	entries_.pop_back();
	}

	entries_.push_front(Entry());
	entry = &entries_.front();
	entry->origin_ = origin;
	entry->realm_ = realm;
	entry->scheme_ = scheme;
	}
	DCHECK_EQ(origin, entry->origin_);
	DCHECK_EQ(realm, entry->realm_);
	DCHECK_EQ(scheme, entry->scheme_);

	entry->auth_challenge_ = auth_challenge;
	entry->credentials_ = credentials;
	entry->nonce_count_ = 1;
	entry->AddPath(path);

	return entry;
	}

	HttpAuthCache::Entry::~Entry() {
	}

	void HttpAuthCache::Entry::UpdateStaleChallenge(
	const std::string& auth_challenge) {
	auth_challenge_ = auth_challenge;
	nonce_count_ = 1;
	}

	HttpAuthCache::Entry::Entry()
	: scheme_(HttpAuth::AUTH_SCHEME_MAX),
	nonce_count_(0) {
	}

	void HttpAuthCache::Entry::AddPath(const std::string& path) {
	std::string parent_dir = GetParentDirectory(path);
	if (!HasEnclosingPath(parent_dir, NULL)) {
	// Remove any entries that have been subsumed by the new entry.
	paths_.remove_if(IsEnclosedBy(parent_dir));

	// Failsafe to prevent unbounded memory growth of the cache.
	if (paths_.size() >= kMaxNumPathsPerRealmEntry) {
	LOG(WARNING) << "Num path entries for " << origin()
	<< " has grown too large -- evicting";
	paths_.pop_back();
	}

	// Add new path.
	paths_.push_front(parent_dir);
	}
	}

	bool HttpAuthCache::Entry::HasEnclosingPath(const std::string& dir,
	size_t* path_len) {
	DCHECK(GetParentDirectory(dir) == dir);
	for (PathList::const_iterator it = paths_.begin(); it != paths_.end();
	++it) {
	if (IsEnclosingPath(*it, dir)) {
	// No element of paths_ may enclose any other element.
	// Therefore this path is the tightest bound. Important because
	// the length returned is used to determine the cache entry that
	// has the closest enclosing path in LookupByPath().
	if (path_len)
	*path_len = it->length();
	return true;
	}
	}
	return false;
	}

	bool HttpAuthCache::Remove(const GURL& origin,
	const std::string& realm,
	HttpAuth::Scheme scheme,
	const AuthCredentials& credentials) {
	for (EntryList::iterator it = entries_.begin(); it != entries_.end(); ++it) {
	if (it->origin() == origin && it->realm() == realm &&
	it->scheme() == scheme) {
	if (credentials.Equals(it->credentials())) {
	entries_.erase(it);
	return true;
	}
	return false;
	}
	}
	return false;
	}

	bool HttpAuthCache::UpdateStaleChallenge(const GURL& origin,
	const std::string& realm,
	HttpAuth::Scheme scheme,
	const std::string& auth_challenge) {
	HttpAuthCache::Entry* entry = Lookup(origin, realm, scheme);
	if (!entry)
	return false;
	entry->UpdateStaleChallenge(auth_challenge);
	return true;
	}

	void HttpAuthCache::UpdateAllFrom(const HttpAuthCache& other) {
	for (EntryList::const_iterator it = other.entries_.begin();
	it != other.entries_.end(); ++it) {
	// Add an Entry with one of the original entry's paths.
	DCHECK(it->paths_.size() > 0);
	Entry* entry = Add(it->origin(), it->realm(), it->scheme(),
	it->auth_challenge(), it->credentials(),
	it->paths_.back());
	// Copy all other paths.
	for (Entry::PathList::const_reverse_iterator it2 = ++it->paths_.rbegin();
	it2 != it->paths_.rend(); ++it2)
	entry->AddPath(*it2);
	// Copy nonce count (for digest authentication).
	entry->nonce_count_ = it->nonce_count_;
	}
	}

	} // namespace net