net/base/sdch_dictionary.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/base/sdch_dictionary.h"
   6
   7 #include "base/time/clock.h"
   8 #include "base/time/default_clock.h"
   9 #include "base/values.h"
  10 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
  11
  12 namespace {
  13
  14 bool DomainMatch(const GURL& gurl, const std::string& restriction) {
  15   // TODO(jar): This is not precisely a domain match definition.
  16   return gurl.DomainIs(restriction);
  17 }
  18
  19 }  // namespace
  20
  21 namespace net {
  22
  23 SdchDictionary::SdchDictionary(const std::string& dictionary_text,
  24                                size_t offset,
  25                                const std::string& client_hash,
  26                                const std::string& server_hash,
  27                                const GURL& gurl,
  28                                const std::string& domain,
  29                                const std::string& path,
  30                                const base::Time& expiration,
  31                                const std::set<int>& ports)
  32     : text_(dictionary_text, offset),
  33       client_hash_(client_hash),
  34       server_hash_(server_hash),
  35       url_(gurl),
  36       domain_(domain),
  37       path_(path),
  38       expiration_(expiration),
  39       ports_(ports) {
  40 }
  41
  42 SdchDictionary::SdchDictionary(const SdchDictionary& rhs)
  43     : text_(rhs.text_),
  44       client_hash_(rhs.client_hash_),
  45       server_hash_(rhs.server_hash_),
  46       url_(rhs.url_),
  47       domain_(rhs.domain_),
  48       path_(rhs.path_),
  49       expiration_(rhs.expiration_),
  50       ports_(rhs.ports_) {
  51 }
  52
  53 SdchDictionary::~SdchDictionary() {
  54 }
  55
  56 // Security functions restricting loads and use of dictionaries.
  57
  58 // static
  59 SdchProblemCode SdchDictionary::CanSet(const std::string& domain,
  60                                        const std::string& path,
  61                                        const std::set<int>& ports,
  62                                        const GURL& dictionary_url) {
  63   /*
  64    * A dictionary is invalid and must not be stored if any of the following are
  65    * true:
  66    * 1. The dictionary has no Domain attribute.
  67    * 2. The effective host name that derives from the referer URL host name does
  68    *    not domain-match the Domain attribute.
  69    * 3. The Domain attribute is a top level domain.
  70    * 4. The referer URL host is a host domain name (not IP address) and has the
  71    *    form HD, where D is the value of the Domain attribute, and H is a string
  72    *    that contains one or more dots.
  73    * 5. If the dictionary has a Port attribute and the referer URL's port
  74    *    was not in the list.
  75    */
  76
  77   // TODO(jar): Redirects in dictionary fetches might plausibly be problematic,
  78   // and hence the conservative approach is to not allow any redirects (if there
  79   // were any... then don't allow the dictionary to be set).
  80
  81   if (domain.empty())
  82     return SDCH_DICTIONARY_MISSING_DOMAIN_SPECIFIER;  // Domain is required.
  83
  84   if (registry_controlled_domains::GetDomainAndRegistry(
  85           domain, registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES)
  86           .empty()) {
  87     return SDCH_DICTIONARY_SPECIFIES_TOP_LEVEL_DOMAIN;  // domain was a TLD.
  88   }
  89
  90   if (!DomainMatch(dictionary_url, domain))
  91     return SDCH_DICTIONARY_DOMAIN_NOT_MATCHING_SOURCE_URL;
  92
  93   std::string referrer_url_host = dictionary_url.host();
  94   size_t postfix_domain_index = referrer_url_host.rfind(domain);
  95   // See if it is indeed a postfix, or just an internal string.
  96   if (referrer_url_host.size() == postfix_domain_index + domain.size()) {
  97     // It is a postfix... so check to see if there's a dot in the prefix.
  98     size_t end_of_host_index = referrer_url_host.find_first_of('.');
  99     if (referrer_url_host.npos != end_of_host_index &&
 100         end_of_host_index < postfix_domain_index) {
 101       return SDCH_DICTIONARY_REFERER_URL_HAS_DOT_IN_PREFIX;
 102     }
 103   }
 104
 105   if (!ports.empty() && 0 == ports.count(dictionary_url.EffectiveIntPort()))
 106     return SDCH_DICTIONARY_PORT_NOT_MATCHING_SOURCE_URL;
 107
 108   return SDCH_OK;
 109 }
 110
 111 SdchProblemCode SdchDictionary::CanUse(const GURL& target_url) const {
 112   /*
 113    * 1. The request URL's host name domain-matches the Domain attribute of the
 114    *    dictionary.
 115    * 2. If the dictionary has a Port attribute, the request port is one of the
 116    *     ports listed in the Port attribute.
 117    * 3. The request URL path-matches the path attribute of the dictionary.
 118    *    We can override (ignore) item (4) only when we have explicitly enabled
 119    *    HTTPS support AND the dictionary acquisition scheme matches the target
 120    *   url scheme.
 121    */
 122   if (!DomainMatch(target_url, domain_))
 123     return SDCH_DICTIONARY_FOUND_HAS_WRONG_DOMAIN;
 124
 125   if (!ports_.empty() && 0 == ports_.count(target_url.EffectiveIntPort()))
 126     return SDCH_DICTIONARY_FOUND_HAS_WRONG_PORT_LIST;
 127
 128   if (path_.size() && !PathMatch(target_url.path(), path_))
 129     return SDCH_DICTIONARY_FOUND_HAS_WRONG_PATH;
 130
 131   if (target_url.SchemeIsCryptographic() != url_.SchemeIsCryptographic())
 132     return SDCH_DICTIONARY_FOUND_HAS_WRONG_SCHEME;
 133
 134   // TODO(jar): Remove overly restrictive failsafe test (added per security
 135   // review) when we have a need to be more general.
 136   if (!target_url.SchemeIsHTTPOrHTTPS())
 137     return SDCH_ATTEMPT_TO_DECODE_NON_HTTP_DATA;
 138
 139   return SDCH_OK;
 140 }
 141
 142 // static
 143 bool SdchDictionary::PathMatch(const std::string& path,
 144                                const std::string& restriction) {
 145   /*  Must be either:
 146    *  1. P2 is equal to P1
 147    *  2. P2 is a prefix of P1 and either the final character in P2 is "/"
 148    *     or the character following P2 in P1 is "/".
 149    */
 150   if (path == restriction)
 151     return true;
 152   size_t prefix_length = restriction.size();
 153   if (prefix_length > path.size())
 154     return false;  // Can't be a prefix.
 155   if (0 != path.compare(0, prefix_length, restriction))
 156     return false;
 157   return restriction[prefix_length - 1] == '/' || path[prefix_length] == '/';
 158 }
 159
 160 bool SdchDictionary::Expired() const {
 161   return base::Time::Now() > expiration_;
 162 }
 163
 164 }  // namespace net