Resurrect http_transport_libcurl

Bug: chromium:1077284
Change-Id: I19eed6072dd7854b81f7fa8c25470b18b3bc1ffd
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/2037803
Commit-Queue: Joshua Peraza <jperaza@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>

build/install_linux_sysroot.py

@@ -29,8 +29,8 @@ SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 # https://cs.chromium.org/chromium/src/build/linux/sysroot_scripts/sysroots.json
 SERVER = 'https://commondatastorage.googleapis.com'
 PATH = 'chrome-linux-sysroot/toolchain'
-REVISION = '3c248ba4290a5ad07085b7af07e6785bf1ae5b66'
+REVISION = '43a87bbebccad99325fdcf34166295b121ee15c7'
-FILENAME = 'debian_stretch_amd64_sysroot.tar.xz'
+FILENAME = 'debian_sid_amd64_sysroot.tar.xz'
 
 
 def main():

handler/crash_report_upload_thread.cc

@@ -294,6 +294,10 @@ CrashReportUploadThread::UploadResult CrashReportUploadThread::UploadReport(
                                            "application/octet-stream");
 
   std::unique_ptr<HTTPTransport> http_transport(HTTPTransport::Create());
+  if (!http_transport) {
+    return UploadResult::kPermanentFailure;
+  }
+
   HTTPHeaders content_headers;
   http_multipart_builder.PopulateContentHeaders(&content_headers);
   for (const auto& content_header : content_headers) {

util/BUILD.gn

@@ -387,7 +387,7 @@ crashpad_static_library("util") {
 
   deps = []
 
-  if (crashpad_is_linux || crashpad_is_fuchsia || crashpad_is_android) {
+  if (crashpad_http_transport_impl == "socket") {
     sources += [ "net/http_transport_socket.cc" ]
     if (crashpad_use_boringssl_for_http_transport_socket) {
       defines += [ "CRASHPAD_USE_BORINGSSL" ]
@@ -401,6 +401,8 @@ crashpad_static_library("util") {
         ]
       }
     }
+  } else if (crashpad_http_transport_impl == "libcurl") {
+    sources += [ "net/http_transport_libcurl.cc" ]
   }
 
   if (crashpad_is_android) {

util/misc/no_cfi_icall.h

@@ -123,6 +123,9 @@ class NoCfiIcall {
   //! \param function A pointer to the function to be called.
   explicit NoCfiIcall(Functor function) : function_(function) {}
 
+  //! \see NoCfiIcall
+  NoCfiIcall() : function_(static_cast<Functor>(nullptr)) {}
+
   //! \see NoCfiIcall
   template <typename PointerType,
             typename = std::enable_if_t<
@@ -142,6 +145,20 @@ class NoCfiIcall {
 
   ~NoCfiIcall() = default;
 
+  //! \brief Updates the pointer to the function to be called.
+  //!
+  //! \param function A pointer to the function to be called.
+  void SetPointer(Functor function) { function_ = function; }
+
+  //! \see SetPointer
+  template <typename PointerType,
+            typename = std::enable_if_t<
+                std::is_same<typename std::remove_cv<PointerType>::type,
+                             void*>::value>>
+  void SetPointer(PointerType function) {
+    function_ = reinterpret_cast<Functor>(function);
+  }
+
   //! \brief Calls the function without sanitization by cfi-icall.
   template <typename... RunArgs>
   decltype(auto) operator()(RunArgs&&... args) const {

util/net/http_transport_libcurl.cc

@@ -0,0 +1,538 @@
+// Copyright 2017 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "util/net/http_transport.h"
+
+#include <curl/curl.h>
+#include <dlfcn.h>
+#include <string.h>
+#include <sys/utsname.h>
+
+#include <algorithm>
+#include <limits>
+
+#include "base/check.h"
+#include "base/logging.h"
+#include "base/numerics/safe_math.h"
+#include "base/scoped_generic.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/stringprintf.h"
+#include "build/build_config.h"
+#include "package.h"
+#include "util/misc/no_cfi_icall.h"
+#include "util/net/http_body.h"
+#include "util/numeric/safe_assignment.h"
+
+namespace crashpad {
+
+namespace {
+
+// Crashpad depends on libcurl via dlopen() in order to maximize its tolerance
+// of various libcurl flavors and installation configurations. This class serves
+// as a linkage table for libcurl procedures.
+class Libcurl {
+ public:
+  static bool Initialized() {
+    static bool initialized = Get()->Initialize();
+    return initialized;
+  }
+
+  static void CurlEasyCleanup(CURL* curl) {
+    return Get()->curl_easy_cleanup_(curl);
+  }
+
+  static CURL* CurlEasyInit() { return Get()->curl_easy_init_(); }
+
+  static CURLcode CurlEasyPerform(CURL* curl) {
+    return Get()->curl_easy_perform_(curl);
+  }
+
+  static const char* CurlEasyStrError(CURLcode code) {
+    return Get()->curl_easy_strerror_(code);
+  }
+
+  template <typename Pointer>
+  static CURLcode CurlEasyGetInfo(CURL* curl, CURLINFO info, Pointer out) {
+    return Get()->curl_easy_getinfo_(curl, info, out);
+  }
+
+  template <typename Pointer>
+  static CURLcode CurlEasySetOpt(CURL* curl, CURLoption option, Pointer param) {
+    return Get()->curl_easy_setopt_(curl, option, param);
+  }
+
+  static CURLcode CurlGlobalInit(long flags) {
+    return Get()->curl_global_init_(flags);
+  }
+
+  static void CurlSlistFreeAll(struct curl_slist* slist) {
+    return Get()->curl_slist_free_all_(slist);
+  }
+
+  static struct curl_slist* CurlSlistAppend(struct curl_slist* slist,
+                                            const char* data) {
+    return Get()->curl_slist_append_(slist, data);
+  }
+
+  static char* CurlVersion() { return Get()->curl_version_(); }
+
+ private:
+  Libcurl() = default;
+  ~Libcurl() = delete;
+
+  static Libcurl* Get() {
+    static Libcurl* instance = new Libcurl();
+    return instance;
+  }
+
+  bool Initialize() {
+    void* libcurl = []() {
+      std::vector<std::string> errors;
+      for (const auto& lib : {
+               "libcurl.so",
+               "libcurl-gnutls.so.4",
+               "libcurl-nss.so.4",
+               "libcurl.so.4",
+           }) {
+        void* libcurl = dlopen(lib, RTLD_LAZY | RTLD_LOCAL);
+        if (libcurl) {
+          return libcurl;
+        }
+        errors.emplace_back(dlerror());
+      }
+      for (const auto& message : errors) {
+        LOG(ERROR) << "dlopen:" << message;
+      }
+      return static_cast<void*>(nullptr);
+    }();
+    if (!libcurl) {
+      return false;
+    }
+
+#define LINK_OR_RETURN_FALSE(symbol)               \
+  do {                                             \
+    symbol##_.SetPointer(dlsym(libcurl, #symbol)); \
+    if (!symbol##_) {                              \
+      LOG(ERROR) << "dlsym:" << dlerror();         \
+      return false;                                \
+    }                                              \
+  } while (0);
+
+    LINK_OR_RETURN_FALSE(curl_easy_cleanup);
+    LINK_OR_RETURN_FALSE(curl_easy_init);
+    LINK_OR_RETURN_FALSE(curl_easy_perform);
+    LINK_OR_RETURN_FALSE(curl_easy_strerror);
+    LINK_OR_RETURN_FALSE(curl_easy_getinfo);
+    LINK_OR_RETURN_FALSE(curl_easy_setopt);
+    LINK_OR_RETURN_FALSE(curl_global_init);
+    LINK_OR_RETURN_FALSE(curl_slist_free_all);
+    LINK_OR_RETURN_FALSE(curl_slist_append);
+    LINK_OR_RETURN_FALSE(curl_version);
+
+#undef LINK_OR_RETURN_FALSE
+
+    return true;
+  }
+
+  NoCfiIcall<decltype(curl_easy_cleanup)*> curl_easy_cleanup_;
+  NoCfiIcall<decltype(curl_easy_init)*> curl_easy_init_;
+  NoCfiIcall<decltype(curl_easy_perform)*> curl_easy_perform_;
+  NoCfiIcall<decltype(curl_easy_strerror)*> curl_easy_strerror_;
+  NoCfiIcall<decltype(curl_easy_getinfo)*> curl_easy_getinfo_;
+  NoCfiIcall<decltype(curl_easy_setopt)*> curl_easy_setopt_;
+  NoCfiIcall<decltype(curl_global_init)*> curl_global_init_;
+  NoCfiIcall<decltype(curl_slist_free_all)*> curl_slist_free_all_;
+  NoCfiIcall<decltype(curl_slist_append)*> curl_slist_append_;
+  NoCfiIcall<decltype(curl_version)*> curl_version_;
+
+  DISALLOW_COPY_AND_ASSIGN(Libcurl);
+};
+
+std::string UserAgent() {
+  std::string user_agent = base::StringPrintf(
+      "%s/%s %s", PACKAGE_NAME, PACKAGE_VERSION, Libcurl::CurlVersion());
+
+  utsname os;
+  if (uname(&os) != 0) {
+    PLOG(WARNING) << "uname";
+  } else {
+    // Match the architecture name that would be used by the kernel, so that the
+    // strcmp() below can omit the kernel’s architecture name if it’s the same
+    // as the user process’ architecture. On Linux, these names are normally
+    // defined in each architecture’s Makefile as UTS_MACHINE, but can be
+    // overridden in architecture-specific configuration as COMPAT_UTS_MACHINE.
+    // See linux-4.9.17/arch/*/Makefile and
+    // linux-4.9.17/arch/*/include/asm/compat.h. In turn, on some systems, these
+    // names are further overridden or refined in early kernel startup code by
+    // modifying the string returned by linux-4.9.17/include/linux/utsname.h
+    // init_utsname() as noted.
+#if defined(ARCH_CPU_X86)
+    // linux-4.9.17/arch/x86/kernel/cpu/bugs.c check_bugs() sets the first digit
+    // to 4, 5, or 6, but no higher.
+#if defined(__i686__)
+    static constexpr char arch[] = "i686";
+#elif defined(__i586__)
+    static constexpr char arch[] = "i586";
+#elif defined(__i486__)
+    static constexpr char arch[] = "i486";
+#else
+    static constexpr char arch[] = "i386";
+#endif
+#elif defined(ARCH_CPU_X86_64)
+    static constexpr char arch[] = "x86_64";
+#elif defined(ARCH_CPU_ARMEL)
+    // linux-4.9.17/arch/arm/kernel/setup.c setup_processor() bases the string
+    // on the ARM processor name and a character identifying little- or
+    // big-endian. The processor name comes from a definition in
+    // arch/arm/mm/proc-*.S.
+#if defined(__ARM_ARCH_4T__)
+    static constexpr char arch[] =
+        "armv4t"
+#elif defined(__ARM_ARCH_5TEJ__)
+    static constexpr char arch[] =
+        "armv5tej"
+#elif defined(__ARM_ARCH_5TE__)
+    static constexpr char arch[] =
+        "armv5te"
+#elif defined(__ARM_ARCH_5T__)
+    static constexpr char arch[] =
+        "armv5t"
+#elif defined(__ARM_ARCH_7M__)
+    static constexpr char arch[] =
+        "armv7m"
+#else
+    // Most ARM architectures fall into here, including all profile variants of
+    // armv6, armv7, armv8, with one exception, armv7m, handled above.
+    // xstr(__ARM_ARCH) will be the architecture revision number, such as 6, 7,
+    // or 8.
+#define xstr(s) str(s)
+#define str(s) #s
+    static constexpr char arch[] =
+        "armv" xstr(__ARM_ARCH)
+#undef str
+#undef xstr
+#endif
+#if defined(ARCH_CPU_LITTLE_ENDIAN)
+        "l";
+#elif defined(ARCH_CPU_BIG_ENDIAN)
+        "b";
+#endif
+#elif defined(ARCH_CPU_ARM64)
+    // ARM64 uses aarch64 or aarch64_be as directed by ELF_PLATFORM. See
+    // linux-4.9.17/arch/arm64/kernel/setup.c setup_arch().
+#if defined(ARCH_CPU_LITTLE_ENDIAN)
+    static constexpr char arch[] = "aarch64";
+#elif defined(ARCH_CPU_BIG_ENDIAN)
+    static constexpr char arch[] = "aarch64_be";
+#endif
+#else
+#error Port
+#endif
+
+    user_agent.append(
+        base::StringPrintf(" %s/%s (%s", os.sysname, os.release, arch));
+    if (strcmp(arch, os.machine) != 0) {
+      user_agent.append(base::StringPrintf("; %s", os.machine));
+    }
+    user_agent.append(1, ')');
+  }
+
+  return user_agent;
+}
+
+std::string CurlErrorMessage(CURLcode curl_err, const std::string& base) {
+  return base::StringPrintf("%s: %s (%d)",
+                            base.c_str(),
+                            Libcurl::CurlEasyStrError(curl_err),
+                            curl_err);
+}
+
+struct ScopedCURLTraits {
+  static CURL* InvalidValue() { return nullptr; }
+  static void Free(CURL* curl) {
+    if (curl) {
+      Libcurl::CurlEasyCleanup(curl);
+    }
+  }
+};
+using ScopedCURL = base::ScopedGeneric<CURL*, ScopedCURLTraits>;
+
+class CurlSList {
+ public:
+  CurlSList() : list_(nullptr) {}
+  ~CurlSList() {
+    if (list_) {
+      Libcurl::CurlSlistFreeAll(list_);
+    }
+  }
+
+  curl_slist* get() const { return list_; }
+
+  bool Append(const char* data) {
+    curl_slist* list = Libcurl::CurlSlistAppend(list_, data);
+    if (!list_) {
+      list_ = list;
+    }
+    return list != nullptr;
+  }
+
+ private:
+  curl_slist* list_;
+
+  DISALLOW_COPY_AND_ASSIGN(CurlSList);
+};
+
+class ScopedClearString {
+ public:
+  explicit ScopedClearString(std::string* string) : string_(string) {}
+
+  ~ScopedClearString() {
+    if (string_) {
+      string_->clear();
+    }
+  }
+
+  void Disarm() { string_ = nullptr; }
+
+ private:
+  std::string* string_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedClearString);
+};
+
+class HTTPTransportLibcurl final : public HTTPTransport {
+ public:
+  HTTPTransportLibcurl();
+  ~HTTPTransportLibcurl() override;
+
+  // HTTPTransport:
+  bool ExecuteSynchronously(std::string* response_body) override;
+
+ private:
+  static size_t ReadRequestBody(char* buffer,
+                                size_t size,
+                                size_t nitems,
+                                void* userdata);
+  static size_t WriteResponseBody(char* buffer,
+                                  size_t size,
+                                  size_t nitems,
+                                  void* userdata);
+
+  DISALLOW_COPY_AND_ASSIGN(HTTPTransportLibcurl);
+};
+
+HTTPTransportLibcurl::HTTPTransportLibcurl() : HTTPTransport() {}
+
+HTTPTransportLibcurl::~HTTPTransportLibcurl() {}
+
+bool HTTPTransportLibcurl::ExecuteSynchronously(std::string* response_body) {
+  DCHECK(body_stream());
+
+  response_body->clear();
+
+  // curl_easy_init() will do this on the first call if it hasn’t been done yet,
+  // but not in a thread-safe way as is done here.
+  static CURLcode curl_global_init_err = []() {
+    return Libcurl::CurlGlobalInit(CURL_GLOBAL_DEFAULT);
+  }();
+  if (curl_global_init_err != CURLE_OK) {
+    LOG(ERROR) << CurlErrorMessage(curl_global_init_err, "curl_global_init");
+    return false;
+  }
+
+  CurlSList curl_headers;
+  ScopedCURL curl(Libcurl::CurlEasyInit());
+  if (!curl.get()) {
+    LOG(ERROR) << "curl_easy_init";
+    return false;
+  }
+
+// These macros wrap the repetitive “try something, log an error and return
+// false on failure” pattern. Macros are convenient because the log messages
+// will point to the correct line number, which can help pinpoint a problem when
+// there are as many calls to these functions as there are here.
+#define TRY_CURL_EASY_SETOPT(curl, option, parameter)               \
+  do {                                                              \
+    CURLcode curl_err =                                             \
+        Libcurl::CurlEasySetOpt((curl), (option), (parameter));     \
+    if (curl_err != CURLE_OK) {                                     \
+      LOG(ERROR) << CurlErrorMessage(curl_err, "curl_easy_setopt"); \
+      return false;                                                 \
+    }                                                               \
+  } while (false)
+#define TRY_CURL_SLIST_APPEND(slist, data) \
+  do {                                     \
+    if (!(slist).Append(data)) {           \
+      LOG(ERROR) << "curl_slist_append";   \
+      return false;                        \
+    }                                      \
+  } while (false)
+
+  TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_USERAGENT, UserAgent().c_str());
+
+  // Accept and automatically decode any encoding that libcurl understands.
+  TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_ACCEPT_ENCODING, "");
+
+  TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_URL, url().c_str());
+
+  if (!root_ca_certificate_path().empty()) {
+    TRY_CURL_EASY_SETOPT(
+        curl.get(), CURLOPT_CAINFO, root_ca_certificate_path().value().c_str());
+  }
+
+  constexpr int kMillisecondsPerSecond = 1E3;
+  TRY_CURL_EASY_SETOPT(curl.get(),
+                       CURLOPT_TIMEOUT_MS,
+                       static_cast<long>(timeout() * kMillisecondsPerSecond));
+
+  // If the request body size is known ahead of time, a Content-Length header
+  // field will be present. Store that to use as CURLOPT_POSTFIELDSIZE_LARGE,
+  // which will both set the Content-Length field in the request header and
+  // inform libcurl of the request body size. Otherwise, use Transfer-Encoding:
+  // chunked, which does not require advance knowledge of the request body size.
+  bool chunked = true;
+  size_t content_length;
+  for (const auto& pair : headers()) {
+    if (pair.first == kContentLength) {
+      chunked = !base::StringToSizeT(pair.second, &content_length);
+      DCHECK(!chunked);
+    } else {
+      TRY_CURL_SLIST_APPEND(curl_headers,
+                            (pair.first + ": " + pair.second).c_str());
+    }
+  }
+
+  if (method() == "POST") {
+    TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_POST, 1l);
+
+    // By default when sending a POST request, libcurl includes an “Expect:
+    // 100-continue” header field. Althogh this header is specified in HTTP/1.1
+    // (RFC 2616 §8.2.3, RFC 7231 §5.1.1), even collection servers that claim to
+    // speak HTTP/1.1 may not respond to it. When sending this header field,
+    // libcurl will wait for one second for the server to respond with a “100
+    // Continue” status before continuing to transmit the request body. This
+    // delay is avoided by telling libcurl not to send this header field at all.
+    // The drawback is that certain HTTP error statuses may not be received
+    // until after substantial amounts of data have been sent to the server.
+    TRY_CURL_SLIST_APPEND(curl_headers, "Expect:");
+
+    if (chunked) {
+      TRY_CURL_SLIST_APPEND(curl_headers, "Transfer-Encoding: chunked");
+    } else {
+      curl_off_t content_length_curl;
+      if (!AssignIfInRange(&content_length_curl, content_length)) {
+        LOG(ERROR) << base::StringPrintf("Content-Length %zu too large",
+                                         content_length);
+        return false;
+      }
+      TRY_CURL_EASY_SETOPT(
+          curl.get(), CURLOPT_POSTFIELDSIZE_LARGE, content_length_curl);
+    }
+  } else if (method() != "GET") {
+    // Untested.
+    TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_CUSTOMREQUEST, method().c_str());
+  }
+
+  TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_HTTPHEADER, curl_headers.get());
+
+  TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_READFUNCTION, ReadRequestBody);
+  TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_READDATA, this);
+  TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_WRITEFUNCTION, WriteResponseBody);
+  TRY_CURL_EASY_SETOPT(curl.get(), CURLOPT_WRITEDATA, response_body);
+
+#undef TRY_CURL_EASY_SETOPT
+#undef TRY_CURL_SLIST_APPEND
+
+  // If a partial response body is received and then a failure occurs, ensure
+  // that response_body is cleared.
+  ScopedClearString clear_response_body(response_body);
+
+  // Do it.
+  CURLcode curl_err = Libcurl::CurlEasyPerform(curl.get());
+  if (curl_err != CURLE_OK) {
+    LOG(ERROR) << CurlErrorMessage(curl_err, "curl_easy_perform");
+    return false;
+  }
+
+  long status;
+  curl_err =
+      Libcurl::CurlEasyGetInfo(curl.get(), CURLINFO_RESPONSE_CODE, &status);
+  if (curl_err != CURLE_OK) {
+    LOG(ERROR) << CurlErrorMessage(curl_err, "curl_easy_getinfo");
+    return false;
+  }
+
+  if (status != 200) {
+    LOG(ERROR) << base::StringPrintf("HTTP status %ld", status);
+    return false;
+  }
+
+  // The response body is complete. Don’t clear it.
+  clear_response_body.Disarm();
+
+  return true;
+}
+
+// static
+size_t HTTPTransportLibcurl::ReadRequestBody(char* buffer,
+                                             size_t size,
+                                             size_t nitems,
+                                             void* userdata) {
+  HTTPTransportLibcurl* self =
+      reinterpret_cast<HTTPTransportLibcurl*>(userdata);
+
+  // This libcurl callback mimics the silly stdio-style fread() interface: size
+  // and nitems have been separated and must be multiplied.
+  base::CheckedNumeric<size_t> checked_len = base::CheckMul(size, nitems);
+  size_t len = checked_len.ValueOrDefault(std::numeric_limits<size_t>::max());
+
+  // Limit the read to what can be expressed in a FileOperationResult.
+  len = std::min(
+      len,
+      static_cast<size_t>(std::numeric_limits<FileOperationResult>::max()));
+
+  FileOperationResult bytes_read = self->body_stream()->GetBytesBuffer(
+      reinterpret_cast<uint8_t*>(buffer), len);
+  if (bytes_read < 0) {
+    return CURL_READFUNC_ABORT;
+  }
+
+  return bytes_read;
+}
+
+// static
+size_t HTTPTransportLibcurl::WriteResponseBody(char* buffer,
+                                               size_t size,
+                                               size_t nitems,
+                                               void* userdata) {
+  std::string* response_body = reinterpret_cast<std::string*>(userdata);
+
+  // This libcurl callback mimics the silly stdio-style fread() interface: size
+  // and nitems have been separated and must be multiplied.
+  base::CheckedNumeric<size_t> checked_len = base::CheckMul(size, nitems);
+  size_t len = checked_len.ValueOrDefault(std::numeric_limits<size_t>::max());
+
+  response_body->append(buffer, len);
+  return len;
+}
+
+}  // namespace
+
+// static
+std::unique_ptr<HTTPTransport> HTTPTransport::Create() {
+  return std::unique_ptr<HTTPTransport>(
+      Libcurl::Initialized() ? new HTTPTransportLibcurl() : nullptr);
+}
+
+}  // namespace crashpad

util/net/tls.gni

@@ -15,6 +15,14 @@
 import("../../build/crashpad_buildconfig.gni")
 
 declare_args() {
+  if (crashpad_is_fuchsia || crashpad_is_android) {
+    crashpad_http_transport_impl = "socket"
+  } else if (crashpad_is_linux) {
+    crashpad_http_transport_impl = "libcurl"
+  } else {
+    crashpad_http_transport_impl = ""
+  }
+
   # TODO(scottmg): https://crbug.com/crashpad/266 fuchsia:DX-690: BoringSSL
   # was removed from the Fuchsia SDK. Re-enable it when we have a way to acquire
   # a BoringSSL lib again.