electron/shell/browser/api/electron_api_protocol.cc

// Copyright (c) 2019 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.

#include "shell/browser/api/electron_api_protocol.h"

#include <string_view>
#include <vector>

#include "base/command_line.h"
#include "base/no_destructor.h"
#include "content/common/url_schemes.h"
#include "content/public/browser/child_process_security_policy.h"
#include "gin/converter.h"
#include "gin/object_template_builder.h"
#include "shell/browser/browser.h"
#include "shell/browser/javascript_environment.h"
#include "shell/browser/net/protocol_source.h"
#include "shell/browser/protocol_registry.h"
#include "shell/common/gin_converters/callback_converter.h"
#include "shell/common/gin_converters/net_converter.h"
#include "shell/common/gin_converters/value_converter.h"
#include "shell/common/gin_helper/dictionary.h"
#include "shell/common/gin_helper/object_template_builder.h"
#include "shell/common/gin_helper/wrappable_pointer_tags.h"
#include "shell/common/node_includes.h"
#include "shell/common/node_util.h"
#include "shell/common/options_switches.h"
#include "third_party/blink/public/common/scheme_registry.h"
#include "url/url_util.h"
#include "v8/include/cppgc/allocation.h"

namespace {

struct SchemeOptions {
  bool standard = false;
  bool secure = false;
  bool bypassCSP = false;
  bool allowServiceWorkers = false;
  bool supportFetchAPI = false;
  bool corsEnabled = false;
  bool stream = false;
  bool codeCache = false;
  bool allowExtensions = false;
};

struct CustomScheme {
  std::string scheme;
  SchemeOptions options;
};

}  // namespace

namespace gin {

template <>
struct Converter<CustomScheme> {
  static bool FromV8(v8::Isolate* isolate,
                     v8::Local<v8::Value> val,
                     CustomScheme* out) {
    gin::Dictionary dict(isolate);
    if (!ConvertFromV8(isolate, val, &dict))
      return false;
    if (!dict.Get("scheme", &(out->scheme)))
      return false;
    gin::Dictionary opt(isolate);
    // options are optional. Default values specified in SchemeOptions are used
    if (dict.Get("privileges", &opt)) {
      opt.Get("standard", &(out->options.standard));
      opt.Get("secure", &(out->options.secure));
      opt.Get("bypassCSP", &(out->options.bypassCSP));
      opt.Get("allowServiceWorkers", &(out->options.allowServiceWorkers));
      opt.Get("supportFetchAPI", &(out->options.supportFetchAPI));
      opt.Get("corsEnabled", &(out->options.corsEnabled));
      opt.Get("stream", &(out->options.stream));
      opt.Get("codeCache", &(out->options.codeCache));
      opt.Get("allowExtensions", &(out->options.allowExtensions));
    }
    return true;
  }
};

}  // namespace gin

namespace electron::api {

const gin::WrapperInfo Protocol::kWrapperInfo =
    electron::MakeWrapperInfo(electron::kElectronProtocol);

std::vector<std::string>& GetStandardSchemes() {
  static base::NoDestructor<std::vector<std::string>> g_standard_schemes;
  return *g_standard_schemes;
}

std::vector<std::string>& GetCodeCacheSchemes() {
  static base::NoDestructor<std::vector<std::string>> g_code_cache_schemes;
  return *g_code_cache_schemes;
}

std::vector<std::string>& GetStreamingSchemes() {
  static base::NoDestructor<std::vector<std::string>> g_streaming_schemes;
  return *g_streaming_schemes;
}

void AddServiceWorkerScheme(const std::string& scheme) {
  // There is no API to add service worker scheme, but there is an API to
  // return const reference to the schemes vector.
  // If in future the API is changed to return a copy instead of reference,
  // the compilation will fail, and we should add a patch at that time.
  auto& mutable_schemes =
      const_cast<std::vector<std::string>&>(content::GetServiceWorkerSchemes());
  mutable_schemes.push_back(scheme);
}

void RegisterSchemesAsPrivileged(gin_helper::ErrorThrower thrower,
                                 v8::Local<v8::Value> val) {
  std::vector<CustomScheme> custom_schemes;
  if (!gin::ConvertFromV8(thrower.isolate(), val, &custom_schemes)) {
    thrower.ThrowError("Argument must be an array of custom schemes.");
    return;
  }

  for (const auto& custom_scheme : custom_schemes) {
    // Schemes are comma-separated for --*-schemes. Sanitize names so
    // extra commas don't trick child processes into splitting one
    // scheme into many.
    if (!Browser::IsValidProtocolScheme(custom_scheme.scheme)) {
      thrower.ThrowError(
          "Invalid scheme name '" + custom_scheme.scheme +
          "'. Scheme names must start with an ASCII letter and contain only "
          "ASCII letters, digits, '+', '-', or '.'.");
      return;
    }
    if (custom_scheme.options.codeCache && !custom_scheme.options.standard) {
      thrower.ThrowError(
          "Code cache can only be enabled when the custom scheme is registered "
          "as standard scheme.");
      return;
    }
  }

  std::vector<std::string> secure_schemes, cspbypassing_schemes, fetch_schemes,
      service_worker_schemes, cors_schemes, extension_schemes;
  for (const auto& custom_scheme : custom_schemes) {
    // Register scheme to privileged list (https, wss, data, chrome-extension)
    if (custom_scheme.options.standard) {
      auto* policy = content::ChildProcessSecurityPolicy::GetInstance();
      url::AddStandardScheme(custom_scheme.scheme.c_str(),
                             url::SCHEME_WITH_HOST);
      GetStandardSchemes().push_back(custom_scheme.scheme);
      policy->RegisterWebSafeScheme(custom_scheme.scheme);
    }
    if (custom_scheme.options.secure) {
      secure_schemes.push_back(custom_scheme.scheme);
      url::AddSecureScheme(custom_scheme.scheme.c_str());
    }
    if (custom_scheme.options.bypassCSP) {
      cspbypassing_schemes.push_back(custom_scheme.scheme);
      url::AddCSPBypassingScheme(custom_scheme.scheme.c_str());
    }
    if (custom_scheme.options.corsEnabled) {
      cors_schemes.push_back(custom_scheme.scheme);
      url::AddCorsEnabledScheme(custom_scheme.scheme.c_str());
    }
    if (custom_scheme.options.supportFetchAPI) {
      fetch_schemes.push_back(custom_scheme.scheme);
    }
    if (custom_scheme.options.allowServiceWorkers) {
      service_worker_schemes.push_back(custom_scheme.scheme);
      AddServiceWorkerScheme(custom_scheme.scheme);
    }
    if (custom_scheme.options.stream) {
      GetStreamingSchemes().push_back(custom_scheme.scheme);
    }
    if (custom_scheme.options.codeCache) {
      GetCodeCacheSchemes().push_back(custom_scheme.scheme);
      blink::CommonSchemeRegistry::RegisterURLSchemeAsSupportingCodeCache(
          custom_scheme.scheme);
    }
    if (custom_scheme.options.allowExtensions) {
      extension_schemes.push_back(custom_scheme.scheme);
      url::AddExtensionScheme(custom_scheme.scheme.c_str());
    }
  }

  const auto AppendSchemesToCmdLine = [](const std::string_view switch_name,
                                         std::vector<std::string> schemes) {
    if (schemes.empty())
      return;
    // Add the schemes to command line switches, so child processes can also
    // register them.
    base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
        switch_name, base::JoinString(schemes, ","));
  };

  AppendSchemesToCmdLine(electron::switches::kSecureSchemes, secure_schemes);
  AppendSchemesToCmdLine(electron::switches::kBypassCSPSchemes,
                         cspbypassing_schemes);
  AppendSchemesToCmdLine(electron::switches::kCORSSchemes, cors_schemes);
  AppendSchemesToCmdLine(electron::switches::kFetchSchemes, fetch_schemes);
  AppendSchemesToCmdLine(electron::switches::kServiceWorkerSchemes,
                         service_worker_schemes);
  AppendSchemesToCmdLine(electron::switches::kExtensionSchemes,
                         extension_schemes);
  AppendSchemesToCmdLine(electron::switches::kStandardSchemes,
                         GetStandardSchemes());
  AppendSchemesToCmdLine(electron::switches::kStreamingSchemes,
                         GetStreamingSchemes());
  AppendSchemesToCmdLine(electron::switches::kCodeCacheSchemes,
                         GetCodeCacheSchemes());
}

Protocol::Protocol(ProtocolRegistry* protocol_registry)
    : protocol_registry_{protocol_registry} {}

Protocol::~Protocol() = default;

// Convert error code to string.
// static
std::string_view Protocol::ErrorCodeToString(Error error) {
  switch (error) {
    case Error::kRegistered:
      return "The scheme has been registered";
    case Error::kNotRegistered:
      return "The scheme has not been registered";
    case Error::kIntercepted:
      return "The scheme has been intercepted";
    case Error::kNotIntercepted:
      return "The scheme has not been intercepted";
    default:
      return "Unexpected error";
  }
}

Protocol::Error Protocol::RegisterProtocol(ProtocolType type,
                                           const std::string& scheme,
                                           const ProtocolHandler& handler) {
  bool added = protocol_registry_->RegisterProtocol(type, scheme, handler);
  return added ? Error::kOK : Error::kRegistered;
}

bool Protocol::UnregisterProtocol(const std::string& scheme,
                                  gin::Arguments* args) {
  bool removed = protocol_registry_->UnregisterProtocol(scheme);
  HandleOptionalCallback(args, removed ? Error::kOK : Error::kNotRegistered);
  return removed;
}

bool Protocol::IsProtocolRegistered(const std::string& scheme) {
  return protocol_registry_->FindRegistered(scheme) != nullptr;
}

void Protocol::RegisterSource(gin_helper::ErrorThrower thrower,
                              const std::string& scheme,
                              const base::DictValue& options) {
  if (ProtocolRegistry::IsBuiltinScheme(scheme)) {
    thrower.ThrowError("Cannot register a source for built-in scheme " +
                       scheme);
    return;
  }
  std::string error;
  scoped_refptr<const ProtocolSource> source =
      ProtocolSource::Create(options, &error);
  if (!source) {
    thrower.ThrowTypeError(error);
    return;
  }
  if (!protocol_registry_->RegisterSource(scheme, std::move(source)))
    thrower.ThrowError("Scheme " + scheme + " is already handled");
}

bool Protocol::UnregisterSource(const std::string& scheme) {
  return protocol_registry_->UnregisterSource(scheme);
}

v8::Local<v8::Value> Protocol::GetSource(v8::Isolate* isolate,
                                         const std::string& scheme) {
  const ProtocolSource* source = protocol_registry_->FindSource(scheme);
  if (!source)
    return v8::Null(isolate);
  return gin::ConvertToV8(isolate, base::ValueView(source->spec()));
}

Protocol::Error Protocol::InterceptProtocol(ProtocolType type,
                                            const std::string& scheme,
                                            const ProtocolHandler& handler) {
  bool added = protocol_registry_->InterceptProtocol(type, scheme, handler);
  return added ? Error::kOK : Error::kIntercepted;
}

bool Protocol::UninterceptProtocol(const std::string& scheme,
                                   gin::Arguments* args) {
  bool removed = protocol_registry_->UninterceptProtocol(scheme);
  HandleOptionalCallback(args, removed ? Error::kOK : Error::kNotIntercepted);
  return removed;
}

bool Protocol::IsProtocolIntercepted(const std::string& scheme) {
  return protocol_registry_->FindIntercepted(scheme) != nullptr;
}

void Protocol::HandleOptionalCallback(gin::Arguments* args, Error error) {
  base::RepeatingCallback<void(v8::Local<v8::Value>)> callback;
  if (args->GetNext(&callback)) {
    util::EmitWarning(
        args->isolate(),
        "The callback argument of protocol module APIs is no longer needed.",
        "ProtocolDeprecateCallback");
    if (error == Error::kOK)
      callback.Run(v8::Null(args->isolate()));
    else
      callback.Run(v8::Exception::Error(
          gin::StringToV8(args->isolate(), ErrorCodeToString(error))));
  }
}

// static
Protocol* Protocol::Create(v8::Isolate* isolate,
                           ProtocolRegistry* protocol_registry) {
  return cppgc::MakeGarbageCollected<Protocol>(
      isolate->GetCppHeap()->GetAllocationHandle(), protocol_registry);
}

// static
Protocol* Protocol::New(gin_helper::ErrorThrower thrower) {
  thrower.ThrowError("Protocol cannot be created from JS");
  return {};
}

// static
void Protocol::FillObjectTemplate(v8::Isolate* isolate,
                                  v8::Local<v8::ObjectTemplate> tmpl) {
  gin::ObjectTemplateBuilder(isolate, GetClassName(), tmpl)
      .SetMethod("registerStringProtocol",
                 &Protocol::RegisterProtocolFor<ProtocolType::kString>)
      .SetMethod("registerBufferProtocol",
                 &Protocol::RegisterProtocolFor<ProtocolType::kBuffer>)
      .SetMethod("registerFileProtocol",
                 &Protocol::RegisterProtocolFor<ProtocolType::kFile>)
      .SetMethod("registerHttpProtocol",
                 &Protocol::RegisterProtocolFor<ProtocolType::kHttp>)
      .SetMethod("registerStreamProtocol",
                 &Protocol::RegisterProtocolFor<ProtocolType::kStream>)
      .SetMethod("registerProtocol",
                 &Protocol::RegisterProtocolFor<ProtocolType::kFree>)
      .SetMethod("unregisterProtocol", &Protocol::UnregisterProtocol)
      .SetMethod("isProtocolRegistered", &Protocol::IsProtocolRegistered)
      .SetMethod("registerSource", &Protocol::RegisterSource)
      .SetMethod("unregisterSource", &Protocol::UnregisterSource)
      .SetMethod("getSource", &Protocol::GetSource)
      .SetMethod("interceptStringProtocol",
                 &Protocol::InterceptProtocolFor<ProtocolType::kString>)
      .SetMethod("interceptBufferProtocol",
                 &Protocol::InterceptProtocolFor<ProtocolType::kBuffer>)
      .SetMethod("interceptFileProtocol",
                 &Protocol::InterceptProtocolFor<ProtocolType::kFile>)
      .SetMethod("interceptHttpProtocol",
                 &Protocol::InterceptProtocolFor<ProtocolType::kHttp>)
      .SetMethod("interceptStreamProtocol",
                 &Protocol::InterceptProtocolFor<ProtocolType::kStream>)
      .SetMethod("interceptProtocol",
                 &Protocol::InterceptProtocolFor<ProtocolType::kFree>)
      .SetMethod("uninterceptProtocol", &Protocol::UninterceptProtocol)
      .SetMethod("isProtocolIntercepted", &Protocol::IsProtocolIntercepted)
      .Build();
}

const gin::WrapperInfo* Protocol::wrapper_info() const {
  return &kWrapperInfo;
}

const char* Protocol::GetHumanReadableName() const {
  return "Electron / Protocol";
}

}  // namespace electron::api

namespace {

void RegisterSchemesAsPrivileged(gin_helper::ErrorThrower thrower,
                                 v8::Local<v8::Value> val) {
  if (electron::Browser::Get()->is_ready()) {
    thrower.ThrowError(
        "protocol.registerSchemesAsPrivileged should be called before "
        "app is ready");
    return;
  }

  electron::api::RegisterSchemesAsPrivileged(thrower, val);
}

void Initialize(v8::Local<v8::Object> exports,
                v8::Local<v8::Value> unused,
                v8::Local<v8::Context> context,
                void* priv) {
  v8::Isolate* const isolate = electron::JavascriptEnvironment::GetIsolate();
  gin_helper::Dictionary dict{isolate, exports};
  dict.Set("Protocol",
           electron::api::Protocol::GetConstructor(
               isolate, context, &electron::api::Protocol::kWrapperInfo));
  dict.SetMethod<&RegisterSchemesAsPrivileged>("registerSchemesAsPrivileged");
  dict.SetMethod<&electron::api::GetStandardSchemes>("getStandardSchemes");
}

}  // namespace

NODE_LINKED_BINDING_CONTEXT_AWARE(electron_browser_protocol, Initialize)