blob: ab8be9eb61544367a0a2eae998daa63597defec9 [file] [log] [blame]
// 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_cache.h"
#include "base/logging.h"
#include "base/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());
DCHECK(origin.SchemeIs("http") || origin.SchemeIs("https"));
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) {
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 string16& username,
const string16& password,
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->username_ = username;
entry->password_ = password;
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 string16& username,
const string16& password) {
for (EntryList::iterator it = entries_.begin(); it != entries_.end(); ++it) {
if (it->origin() == origin && it->realm() == realm &&
it->scheme() == scheme) {
if (username == it->username() && password == it->password()) {
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;
}
} // namespace net