root/chrome/browser/extensions/api/proxy/proxy_api_helpers.cc

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DEFINITIONS

This source file includes following definitions.
  1. CreateDataURLFromPACScript
  2. CreatePACScriptFromDataURL
  3. GetProxyModeFromExtensionPref
  4. GetPacMandatoryFromExtensionPref
  5. GetPacUrlFromExtensionPref
  6. GetPacDataFromExtensionPref
  7. GetProxyServer
  8. GetProxyRulesStringFromExtensionPref
  9. JoinUrlList
  10. GetBypassListFromExtensionPref
  11. CreateProxyConfigDict
  12. CreateProxyRulesDict
  13. CreateProxyServerDict
  14. CreatePacScriptDict
  15. TokenizeToStringList

// Copyright (c) 2012 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.

// Implementation of helper functions for the Chrome Extensions Proxy Settings
// API.
//
// Throughout this code, we report errors to the user by setting an |error|
// parameter, if and only if these errors can be cause by invalid input
// from the extension and we cannot expect that the extensions API has
// caught this error before. In all other cases we are dealing with internal
// errors and log to LOG(ERROR).

#include "chrome/browser/extensions/api/proxy/proxy_api_helpers.h"

#include "base/base64.h"
#include "base/basictypes.h"
#include "base/strings/string_tokenizer.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/values.h"
#include "chrome/browser/extensions/api/proxy/proxy_api_constants.h"
#include "chrome/browser/prefs/proxy_config_dictionary.h"
#include "extensions/common/error_utils.h"
#include "net/base/data_url.h"
#include "net/proxy/proxy_config.h"

namespace extensions {

namespace keys = proxy_api_constants;

namespace proxy_api_helpers {

bool CreateDataURLFromPACScript(const std::string& pac_script,
                                std::string* pac_script_url_base64_encoded) {
  // Encode pac_script in base64.
  std::string pac_script_base64_encoded;
  base::Base64Encode(pac_script, &pac_script_base64_encoded);

  // Make it a correct data url.
  *pac_script_url_base64_encoded =
      std::string(keys::kPACDataUrlPrefix) + pac_script_base64_encoded;
  return true;
}

bool CreatePACScriptFromDataURL(
    const std::string& pac_script_url_base64_encoded,
    std::string* pac_script) {
  GURL url(pac_script_url_base64_encoded);
  if (!url.is_valid())
    return false;

  std::string mime_type;
  std::string charset;
  return net::DataURL::Parse(url, &mime_type, &charset, pac_script);
}

// Extension Pref -> Browser Pref conversion.

bool GetProxyModeFromExtensionPref(const base::DictionaryValue* proxy_config,
                                   ProxyPrefs::ProxyMode* out,
                                   std::string* error,
                                   bool* bad_message) {
  std::string proxy_mode;

  // We can safely assume that this is ASCII due to the allowed enumeration
  // values specified in the extension API JSON.
  proxy_config->GetStringASCII(keys::kProxyConfigMode, &proxy_mode);
  if (!ProxyPrefs::StringToProxyMode(proxy_mode, out)) {
    LOG(ERROR) << "Invalid mode for proxy settings: " << proxy_mode;
    *bad_message = true;
    return false;
  }
  return true;
}

bool GetPacMandatoryFromExtensionPref(const base::DictionaryValue* proxy_config,
                                      bool* out,
                                      std::string* error,
                                      bool* bad_message){
  const base::DictionaryValue* pac_dict = NULL;
  proxy_config->GetDictionary(keys::kProxyConfigPacScript, &pac_dict);
  if (!pac_dict)
    return true;

  bool mandatory_pac = false;
  if (pac_dict->HasKey(keys::kProxyConfigPacScriptMandatory) &&
      !pac_dict->GetBoolean(keys::kProxyConfigPacScriptMandatory,
                            &mandatory_pac)) {
    LOG(ERROR) << "'pacScript.mandatory' could not be parsed.";
    *bad_message = true;
    return false;
  }
  *out = mandatory_pac;
  return true;
}

bool GetPacUrlFromExtensionPref(const base::DictionaryValue* proxy_config,
                                std::string* out,
                                std::string* error,
                                bool* bad_message) {
  const base::DictionaryValue* pac_dict = NULL;
  proxy_config->GetDictionary(keys::kProxyConfigPacScript, &pac_dict);
  if (!pac_dict)
    return true;

  // TODO(battre): Handle UTF-8 URLs (http://crbug.com/72692).
  base::string16 pac_url16;
  if (pac_dict->HasKey(keys::kProxyConfigPacScriptUrl) &&
      !pac_dict->GetString(keys::kProxyConfigPacScriptUrl, &pac_url16)) {
    LOG(ERROR) << "'pacScript.url' could not be parsed.";
    *bad_message = true;
    return false;
  }
  if (!IsStringASCII(pac_url16)) {
    *error = "'pacScript.url' supports only ASCII URLs "
             "(encode URLs in Punycode format).";
    return false;
  }
  *out = base::UTF16ToASCII(pac_url16);
  return true;
}

bool GetPacDataFromExtensionPref(const base::DictionaryValue* proxy_config,
                                 std::string* out,
                                 std::string* error,
                                 bool* bad_message) {
  const base::DictionaryValue* pac_dict = NULL;
  proxy_config->GetDictionary(keys::kProxyConfigPacScript, &pac_dict);
  if (!pac_dict)
    return true;

  base::string16 pac_data16;
  if (pac_dict->HasKey(keys::kProxyConfigPacScriptData) &&
      !pac_dict->GetString(keys::kProxyConfigPacScriptData, &pac_data16)) {
    LOG(ERROR) << "'pacScript.data' could not be parsed.";
    *bad_message = true;
    return false;
  }
  if (!IsStringASCII(pac_data16)) {
    *error = "'pacScript.data' supports only ASCII code"
             "(encode URLs in Punycode format).";
    return false;
  }
  *out = base::UTF16ToASCII(pac_data16);
  return true;
}

bool GetProxyServer(const base::DictionaryValue* proxy_server,
                    net::ProxyServer::Scheme default_scheme,
                    net::ProxyServer* out,
                    std::string* error,
                    bool* bad_message) {
  std::string scheme_string;  // optional.

  // We can safely assume that this is ASCII due to the allowed enumeration
  // values specified in the extension API JSON.
  proxy_server->GetStringASCII(keys::kProxyConfigRuleScheme, &scheme_string);

  net::ProxyServer::Scheme scheme =
      net::ProxyServer::GetSchemeFromURI(scheme_string);
  if (scheme == net::ProxyServer::SCHEME_INVALID)
    scheme = default_scheme;

  // TODO(battre): handle UTF-8 in hostnames (http://crbug.com/72692).
  base::string16 host16;
  if (!proxy_server->GetString(keys::kProxyConfigRuleHost, &host16)) {
    LOG(ERROR) << "Could not parse a 'rules.*.host' entry.";
    *bad_message = true;
    return false;
  }
  if (!IsStringASCII(host16)) {
    *error = ErrorUtils::FormatErrorMessage(
        "Invalid 'rules.???.host' entry '*'. 'host' field supports only ASCII "
        "URLs (encode URLs in Punycode format).",
        base::UTF16ToUTF8(host16));
    return false;
  }
  std::string host = base::UTF16ToASCII(host16);

  int port;  // optional.
  if (!proxy_server->GetInteger(keys::kProxyConfigRulePort, &port))
    port = net::ProxyServer::GetDefaultPortForScheme(scheme);

  *out = net::ProxyServer(scheme, net::HostPortPair(host, port));

  return true;
}

bool GetProxyRulesStringFromExtensionPref(
    const base::DictionaryValue* proxy_config,
    std::string* out,
    std::string* error,
    bool* bad_message) {
  const base::DictionaryValue* proxy_rules = NULL;
  proxy_config->GetDictionary(keys::kProxyConfigRules, &proxy_rules);
  if (!proxy_rules)
    return true;

  // Local data into which the parameters will be parsed. has_proxy describes
  // whether a setting was found for the scheme; proxy_server holds the
  // respective ProxyServer objects containing those descriptions.
  bool has_proxy[keys::SCHEME_MAX + 1];
  net::ProxyServer proxy_server[keys::SCHEME_MAX + 1];

  // Looking for all possible proxy types is inefficient if we have a
  // singleProxy that will supersede per-URL proxies, but it's worth it to keep
  // the code simple and extensible.
  for (size_t i = 0; i <= keys::SCHEME_MAX; ++i) {
    const base::DictionaryValue* proxy_dict = NULL;
    has_proxy[i] = proxy_rules->GetDictionary(keys::field_name[i],
                                              &proxy_dict);
    if (has_proxy[i]) {
      net::ProxyServer::Scheme default_scheme = net::ProxyServer::SCHEME_HTTP;
      if (!GetProxyServer(proxy_dict, default_scheme,
                          &proxy_server[i], error, bad_message)) {
        // Don't set |error| here, as GetProxyServer takes care of that.
        return false;
      }
    }
  }

  COMPILE_ASSERT(keys::SCHEME_ALL == 0, singleProxy_must_be_first_option);

  // Handle case that only singleProxy is specified.
  if (has_proxy[keys::SCHEME_ALL]) {
    for (size_t i = 1; i <= keys::SCHEME_MAX; ++i) {
      if (has_proxy[i]) {
        *error = ErrorUtils::FormatErrorMessage(
            "Proxy rule for * and * cannot be set at the same time.",
            keys::field_name[keys::SCHEME_ALL], keys::field_name[i]);
        return false;
      }
    }
    *out = proxy_server[keys::SCHEME_ALL].ToURI();
    return true;
  }

  // Handle case that anything but singleProxy is specified.

  // Build the proxy preference string.
  std::string proxy_pref;
  for (size_t i = 1; i <= keys::SCHEME_MAX; ++i) {
    if (has_proxy[i]) {
      // http=foopy:4010;ftp=socks5://foopy2:80
      if (!proxy_pref.empty())
        proxy_pref.append(";");
      proxy_pref.append(keys::scheme_name[i]);
      proxy_pref.append("=");
      proxy_pref.append(proxy_server[i].ToURI());
    }
  }

  *out = proxy_pref;
  return true;
}

bool JoinUrlList(const base::ListValue* list,
                 const std::string& joiner,
                 std::string* out,
                 std::string* error,
                 bool* bad_message) {
  std::string result;
  for (size_t i = 0; i < list->GetSize(); ++i) {
    if (!result.empty())
      result.append(joiner);

    // TODO(battre): handle UTF-8 (http://crbug.com/72692).
    base::string16 entry;
    if (!list->GetString(i, &entry)) {
      LOG(ERROR) << "'rules.bypassList' could not be parsed.";
      *bad_message = true;
      return false;
    }
    if (!IsStringASCII(entry)) {
      *error = "'rules.bypassList' supports only ASCII URLs "
               "(encode URLs in Punycode format).";
      return false;
    }
    result.append(base::UTF16ToASCII(entry));
  }
  *out = result;
  return true;
}

bool GetBypassListFromExtensionPref(const base::DictionaryValue* proxy_config,
                                    std::string* out,
                                    std::string* error,
                                    bool* bad_message) {
  const base::DictionaryValue* proxy_rules = NULL;
  proxy_config->GetDictionary(keys::kProxyConfigRules, &proxy_rules);
  if (!proxy_rules)
    return true;

  if (!proxy_rules->HasKey(keys::kProxyConfigBypassList)) {
    *out = "";
    return true;
  }
  const base::ListValue* bypass_list = NULL;
  if (!proxy_rules->GetList(keys::kProxyConfigBypassList, &bypass_list)) {
    LOG(ERROR) << "'rules.bypassList' could not be parsed.";
    *bad_message = true;
    return false;
  }

  return JoinUrlList(bypass_list, ",", out, error, bad_message);
}

base::DictionaryValue* CreateProxyConfigDict(
    ProxyPrefs::ProxyMode mode_enum,
    bool pac_mandatory,
    const std::string& pac_url,
    const std::string& pac_data,
    const std::string& proxy_rules_string,
    const std::string& bypass_list,
    std::string* error) {
  base::DictionaryValue* result_proxy_config = NULL;
  switch (mode_enum) {
    case ProxyPrefs::MODE_DIRECT:
      result_proxy_config = ProxyConfigDictionary::CreateDirect();
      break;
    case ProxyPrefs::MODE_AUTO_DETECT:
      result_proxy_config = ProxyConfigDictionary::CreateAutoDetect();
      break;
    case ProxyPrefs::MODE_PAC_SCRIPT: {
      std::string url;
      if (!pac_url.empty()) {
        url = pac_url;
      } else if (!pac_data.empty()) {
        if (!CreateDataURLFromPACScript(pac_data, &url)) {
          *error = "Internal error, at base64 encoding of 'pacScript.data'.";
          return NULL;
        }
      } else {
        *error = "Proxy mode 'pac_script' requires a 'pacScript' field with "
                 "either a 'url' field or a 'data' field.";
        return NULL;
      }
      result_proxy_config =
          ProxyConfigDictionary::CreatePacScript(url, pac_mandatory);
      break;
    }
    case ProxyPrefs::MODE_FIXED_SERVERS: {
      if (proxy_rules_string.empty()) {
        *error = "Proxy mode 'fixed_servers' requires a 'rules' field.";
        return NULL;
      }
      result_proxy_config = ProxyConfigDictionary::CreateFixedServers(
          proxy_rules_string, bypass_list);
      break;
    }
    case ProxyPrefs::MODE_SYSTEM:
      result_proxy_config = ProxyConfigDictionary::CreateSystem();
      break;
    case ProxyPrefs::kModeCount:
      NOTREACHED();
  }
  return result_proxy_config;
}

base::DictionaryValue* CreateProxyRulesDict(
    const ProxyConfigDictionary& proxy_config) {
  ProxyPrefs::ProxyMode mode;
  CHECK(proxy_config.GetMode(&mode) && mode == ProxyPrefs::MODE_FIXED_SERVERS);

  scoped_ptr<base::DictionaryValue> extension_proxy_rules(
      new base::DictionaryValue);

  std::string proxy_servers;
  if (!proxy_config.GetProxyServer(&proxy_servers)) {
    LOG(ERROR) << "Missing proxy servers in configuration.";
    return NULL;
  }

  net::ProxyConfig::ProxyRules rules;
  rules.ParseFromString(proxy_servers);

  switch (rules.type) {
    case net::ProxyConfig::ProxyRules::TYPE_NO_RULES:
      return NULL;
    case net::ProxyConfig::ProxyRules::TYPE_SINGLE_PROXY:
      if (!rules.single_proxies.IsEmpty()) {
        extension_proxy_rules->Set(
            keys::field_name[keys::SCHEME_ALL],
            CreateProxyServerDict(rules.single_proxies.Get()));
      }
      break;
    case net::ProxyConfig::ProxyRules::TYPE_PROXY_PER_SCHEME:
      if (!rules.proxies_for_http.IsEmpty()) {
        extension_proxy_rules->Set(
            keys::field_name[keys::SCHEME_HTTP],
            CreateProxyServerDict(rules.proxies_for_http.Get()));
      }
      if (!rules.proxies_for_https.IsEmpty()) {
        extension_proxy_rules->Set(
            keys::field_name[keys::SCHEME_HTTPS],
            CreateProxyServerDict(rules.proxies_for_https.Get()));
      }
      if (!rules.proxies_for_ftp.IsEmpty()) {
        extension_proxy_rules->Set(
            keys::field_name[keys::SCHEME_FTP],
            CreateProxyServerDict(rules.proxies_for_ftp.Get()));
      }
      if (!rules.fallback_proxies.IsEmpty()) {
        extension_proxy_rules->Set(
            keys::field_name[keys::SCHEME_FALLBACK],
            CreateProxyServerDict(rules.fallback_proxies.Get()));
      }
      break;
  }

  // If we add a new scheme some time, we need to also store a new dictionary
  // representing this scheme in the code above.
  COMPILE_ASSERT(keys::SCHEME_MAX == 4, SCHEME_FORGOTTEN);

  if (proxy_config.HasBypassList()) {
    std::string bypass_list_string;
    if (!proxy_config.GetBypassList(&bypass_list_string)) {
      LOG(ERROR) << "Invalid bypassList in configuration.";
      return NULL;
    }
    base::ListValue* bypass_list =
        TokenizeToStringList(bypass_list_string, ",;");
    extension_proxy_rules->Set(keys::kProxyConfigBypassList, bypass_list);
  }

  return extension_proxy_rules.release();
}

base::DictionaryValue* CreateProxyServerDict(const net::ProxyServer& proxy) {
  scoped_ptr<base::DictionaryValue> out(new base::DictionaryValue);
  switch (proxy.scheme()) {
    case net::ProxyServer::SCHEME_HTTP:
      out->SetString(keys::kProxyConfigRuleScheme, "http");
      break;
    case net::ProxyServer::SCHEME_HTTPS:
      out->SetString(keys::kProxyConfigRuleScheme, "https");
      break;
    case net::ProxyServer::SCHEME_QUIC:
      out->SetString(keys::kProxyConfigRuleScheme, "quic");
      break;
    case net::ProxyServer::SCHEME_SOCKS4:
      out->SetString(keys::kProxyConfigRuleScheme, "socks4");
      break;
    case net::ProxyServer::SCHEME_SOCKS5:
      out->SetString(keys::kProxyConfigRuleScheme, "socks5");
      break;
    case net::ProxyServer::SCHEME_DIRECT:
    case net::ProxyServer::SCHEME_INVALID:
      NOTREACHED();
      return NULL;
  }
  out->SetString(keys::kProxyConfigRuleHost, proxy.host_port_pair().host());
  out->SetInteger(keys::kProxyConfigRulePort, proxy.host_port_pair().port());
  return out.release();
}

base::DictionaryValue* CreatePacScriptDict(
    const ProxyConfigDictionary& proxy_config) {
  ProxyPrefs::ProxyMode mode;
  CHECK(proxy_config.GetMode(&mode) && mode == ProxyPrefs::MODE_PAC_SCRIPT);

  scoped_ptr<base::DictionaryValue> pac_script_dict(new base::DictionaryValue);
  std::string pac_url;
  if (!proxy_config.GetPacUrl(&pac_url)) {
    LOG(ERROR) << "Invalid proxy configuration. Missing PAC URL.";
    return NULL;
  }
  bool pac_mandatory = false;
  if (!proxy_config.GetPacMandatory(&pac_mandatory)) {
    LOG(ERROR) << "Invalid proxy configuration. Missing PAC mandatory field.";
    return NULL;
  }

  if (pac_url.find("data") == 0) {
    std::string pac_data;
    if (!CreatePACScriptFromDataURL(pac_url, &pac_data)) {
      LOG(ERROR) << "Cannot decode base64-encoded PAC data URL: " << pac_url;
      return NULL;
    }
    pac_script_dict->SetString(keys::kProxyConfigPacScriptData, pac_data);
  } else {
    pac_script_dict->SetString(keys::kProxyConfigPacScriptUrl, pac_url);
  }
  pac_script_dict->SetBoolean(keys::kProxyConfigPacScriptMandatory,
                              pac_mandatory);
  return pac_script_dict.release();
}

base::ListValue* TokenizeToStringList(const std::string& in,
                                const std::string& delims) {
  base::ListValue* out = new base::ListValue;
  base::StringTokenizer entries(in, delims);
  while (entries.GetNext())
    out->Append(new base::StringValue(entries.token()));
  return out;
}

}  // namespace proxy_api_helpers
}  // namespace extensions

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