Revert 282546 "Enforce SafetyMode for YouTube if prefs::kForceSa..."

trunk/src/chrome/browser/net/safe_search_util.cc

-// Copyright 2014 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 "chrome/browser/net/safe_search_util.h"
-
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "base/logging.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_piece.h"
-#include "base/strings/string_split.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-#include "chrome/common/url_constants.h"
-#include "components/google/core/browser/google_util.h"
-#include "net/cookies/cookie_util.h"
-#include "net/http/http_request_headers.h"
-#include "net/url_request/url_request.h"
-#include "url/gurl.h"
-
-namespace {
-
-const char kYouTubePrefCookieName[] = "PREF";
-// YouTube pref flags are stored in bit masks of 31 bits each, called "f1",
-// "f2" etc. The Safety Mode flag is bit 58, so bit 27 in "f2".
-const char kYouTubePrefCookieSafetyModeFlagsEntryName[] = "f2";
-const int kYouTubePrefCookieSafetyModeFlagsEntryValue = (1 << 27);
-
-// Returns whether a URL parameter, |first_parameter| (e.g. foo=bar), has the
-// same key as the the |second_parameter| (e.g. foo=baz). Both parameters
-// must be in key=value form.
-bool HasSameParameterKey(const std::string& first_parameter,
-                         const std::string& second_parameter) {
-  DCHECK(second_parameter.find("=") != std::string::npos);
-  // Prefix for "foo=bar" is "foo=".
-  std::string parameter_prefix = second_parameter.substr(
-      0, second_parameter.find("=") + 1);
-  return StartsWithASCII(first_parameter, parameter_prefix, false);
-}
-
-// Examines the query string containing parameters and adds the necessary ones
-// so that SafeSearch is active. |query| is the string to examine and the
-// return value is the |query| string modified such that SafeSearch is active.
-std::string AddSafeSearchParameters(const std::string& query) {
-  std::vector<std::string> new_parameters;
-  std::string safe_parameter = chrome::kSafeSearchSafeParameter;
-  std::string ssui_parameter = chrome::kSafeSearchSsuiParameter;
-
-  std::vector<std::string> parameters;
-  base::SplitString(query, '&', &parameters);
-
-  std::vector<std::string>::iterator it;
-  for (it = parameters.begin(); it < parameters.end(); ++it) {
-    if (!HasSameParameterKey(*it, safe_parameter) &&
-        !HasSameParameterKey(*it, ssui_parameter)) {
-      new_parameters.push_back(*it);
-    }
-  }
-
-  new_parameters.push_back(safe_parameter);
-  new_parameters.push_back(ssui_parameter);
-  return JoinString(new_parameters, '&');
-}
-
-bool IsYouTubePrefCookie(const net::cookie_util::ParsedRequestCookie& cookie) {
-  return cookie.first == base::StringPiece(kYouTubePrefCookieName);
-}
-
-bool IsYouTubePrefCookieSafetyModeFlagsEntry(
-    const std::pair<std::string, std::string>& pref_entry) {
-  return pref_entry.first == kYouTubePrefCookieSafetyModeFlagsEntryName;
-}
-
-std::string JoinStringKeyValuePair(
-    const base::StringPairs::value_type& key_value,
-    char delimiter) {
-  return key_value.first + delimiter + key_value.second;
-}
-
-// Does the opposite of base::SplitStringIntoKeyValuePairs() from
-// base/strings/string_util.h.
-std::string JoinStringKeyValuePairs(const base::StringPairs& pairs,
-                                    char key_value_delimiter,
-                                    char key_value_pair_delimiter) {
-  if (pairs.empty())
-    return std::string();
-
-  base::StringPairs::const_iterator it = pairs.begin();
-  std::string result = JoinStringKeyValuePair(*it, key_value_delimiter);
-  ++it;
-
-  for (; it != pairs.end(); ++it) {
-    result += key_value_pair_delimiter;
-    result += JoinStringKeyValuePair(*it, key_value_delimiter);
-  }
-
-  return result;
-}
-
-} // namespace
-
-namespace safe_search_util {
-
-// If |request| is a request to Google Web Search the function
-// enforces that the SafeSearch query parameters are set to active.
-// Sets the query part of |new_url| with the new value of the parameters.
-void ForceGoogleSafeSearch(const net::URLRequest* request, GURL* new_url) {
-  if (!google_util::IsGoogleSearchUrl(request->url()) &&
-      !google_util::IsGoogleHomePageUrl(request->url()))
-    return;
-
-  std::string query = request->url().query();
-  std::string new_query = AddSafeSearchParameters(query);
-  if (query == new_query)
-    return;
-
-  GURL::Replacements replacements;
-  replacements.SetQueryStr(new_query);
-  *new_url = request->url().ReplaceComponents(replacements);
-}
-
-// If |request| is a request to YouTube, enforces YouTube's Safety Mode by
-// adding/modifying YouTube's PrefCookie header.
-void ForceYouTubeSafetyMode(const net::URLRequest* request,
-                            net::HttpRequestHeaders* headers) {
-  if (!google_util::IsYoutubeDomainUrl(
-          request->url(),
-          google_util::ALLOW_SUBDOMAIN,
-          google_util::DISALLOW_NON_STANDARD_PORTS))
-    return;
-
-  // Get the cookie string from the headers and parse it into key/value pairs.
-  std::string cookie_string;
-  headers->GetHeader(base::StringPiece(net::HttpRequestHeaders::kCookie),
-                     &cookie_string);
-  net::cookie_util::ParsedRequestCookies cookies;
-  net::cookie_util::ParseRequestCookieLine(cookie_string, &cookies);
-
-  // Find YouTube's pref cookie, or add it if it doesn't exist yet.
-  net::cookie_util::ParsedRequestCookies::iterator pref_it =
-      std::find_if(cookies.begin(), cookies.end(), IsYouTubePrefCookie);
-  if (pref_it == cookies.end()) {
-    cookies.push_back(std::make_pair(base::StringPiece(kYouTubePrefCookieName),
-                                     base::StringPiece()));
-    pref_it = cookies.end() - 1;
-  }
-
-  // The pref cookie's value may be quoted. If so, remove the quotes.
-  std::string pref_string = pref_it->second.as_string();
-  bool pref_string_quoted = false;
-  if (pref_string.size() >= 2 &&
-      pref_string[0] == '\"' &&
-      pref_string[pref_string.size() - 1] == '\"') {
-    pref_string_quoted = true;
-    pref_string = pref_string.substr(1, pref_string.length() - 2);
-  }
-
-  // The pref cookie's value consists of key/value pairs. Parse them.
-  base::StringPairs pref_values;
-  base::SplitStringIntoKeyValuePairs(pref_string, '=', '&', &pref_values);
-
-  // Find the "flags" entry that contains the Safety Mode flag, or add it if it
-  // doesn't exist.
-  base::StringPairs::iterator flag_it =
-      std::find_if(pref_values.begin(), pref_values.end(),
-                   IsYouTubePrefCookieSafetyModeFlagsEntry);
-  int flag_value = 0;
-  if (flag_it == pref_values.end()) {
-    pref_values.push_back(
-        std::make_pair(std::string(kYouTubePrefCookieSafetyModeFlagsEntryName),
-                       std::string()));
-    flag_it = pref_values.end() - 1;
-  } else {
-    base::HexStringToInt(base::StringPiece(flag_it->second), &flag_value);
-  }
-
-  // Set the Safety Mode bit.
-  flag_value |= kYouTubePrefCookieSafetyModeFlagsEntryValue;
-
-  // Finally, put it all back together and replace the original cookie string.
-  flag_it->second = base::StringPrintf("%x", flag_value);
-  pref_string = JoinStringKeyValuePairs(pref_values, '=', '&');
-  if (pref_string_quoted) {
-    pref_string = '\"' + pref_string + '\"';
-  }
-  pref_it->second = base::StringPiece(pref_string);
-  cookie_string = net::cookie_util::SerializeRequestCookieLine(cookies);
-  headers->SetHeader(base::StringPiece(net::HttpRequestHeaders::kCookie),
-                     base::StringPiece(cookie_string));
-}
-
-}  // namespace safe_search_util