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      1 // Copyright (c) 2011 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 "crypto/openssl_util.h"
      6 
      7 #include <openssl/err.h>
      8 #include <openssl/ssl.h>
      9 #include <openssl/cpu.h>
     10 
     11 #include "base/logging.h"
     12 #include "base/memory/scoped_vector.h"
     13 #include "base/memory/singleton.h"
     14 #include "base/strings/string_piece.h"
     15 #include "base/synchronization/lock.h"
     16 #include "build/build_config.h"
     17 
     18 #if defined(OS_ANDROID) && defined(ARCH_CPU_ARMEL)
     19 #include <cpu-features.h>
     20 #include "base/cpu.h"
     21 #endif
     22 
     23 namespace crypto {
     24 
     25 namespace {
     26 
     27 void CurrentThreadId(CRYPTO_THREADID* id) {
     28   CRYPTO_THREADID_set_numeric(
     29       id, static_cast<unsigned long>(base::PlatformThread::CurrentId()));
     30 }
     31 
     32 // Singleton for initializing and cleaning up the OpenSSL library.
     33 class OpenSSLInitSingleton {
     34  public:
     35   static OpenSSLInitSingleton* GetInstance() {
     36     // We allow the SSL environment to leak for multiple reasons:
     37     //   -  it is used from a non-joinable worker thread that is not stopped on
     38     //      shutdown, hence may still be using OpenSSL library after the AtExit
     39     //      runner has completed.
     40     //   -  There are other OpenSSL related singletons (e.g. the client socket
     41     //      context) who's cleanup depends on the global environment here, but
     42     //      we can't control the order the AtExit handlers will run in so
     43     //      allowing the global environment to leak at least ensures it is
     44     //      available for those other singletons to reliably cleanup.
     45     return Singleton<OpenSSLInitSingleton,
     46                LeakySingletonTraits<OpenSSLInitSingleton> >::get();
     47   }
     48  private:
     49   friend struct DefaultSingletonTraits<OpenSSLInitSingleton>;
     50   OpenSSLInitSingleton() {
     51     SSL_load_error_strings();
     52     SSL_library_init();
     53     int num_locks = CRYPTO_num_locks();
     54     locks_.reserve(num_locks);
     55     for (int i = 0; i < num_locks; ++i)
     56       locks_.push_back(new base::Lock());
     57     CRYPTO_set_locking_callback(LockingCallback);
     58     CRYPTO_THREADID_set_callback(CurrentThreadId);
     59 
     60 #if defined(OS_ANDROID) && defined(ARCH_CPU_ARMEL)
     61     const bool has_neon =
     62         (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
     63     if (has_neon)
     64       CRYPTO_set_NEON_capable(1);
     65     // See https://code.google.com/p/chromium/issues/detail?id=341598
     66     base::CPU cpu;
     67     CRYPTO_set_NEON_functional(!cpu.has_broken_neon());
     68 #endif
     69   }
     70 
     71   ~OpenSSLInitSingleton() {
     72     CRYPTO_set_locking_callback(NULL);
     73     EVP_cleanup();
     74     ERR_free_strings();
     75   }
     76 
     77   static void LockingCallback(int mode, int n, const char* file, int line) {
     78     OpenSSLInitSingleton::GetInstance()->OnLockingCallback(mode, n, file, line);
     79   }
     80 
     81   void OnLockingCallback(int mode, int n, const char* file, int line) {
     82     CHECK_LT(static_cast<size_t>(n), locks_.size());
     83     if (mode & CRYPTO_LOCK)
     84       locks_[n]->Acquire();
     85     else
     86       locks_[n]->Release();
     87   }
     88 
     89   // These locks are used and managed by OpenSSL via LockingCallback().
     90   ScopedVector<base::Lock> locks_;
     91 
     92   DISALLOW_COPY_AND_ASSIGN(OpenSSLInitSingleton);
     93 };
     94 
     95 // Callback routine for OpenSSL to print error messages. |str| is a
     96 // NULL-terminated string of length |len| containing diagnostic information
     97 // such as the library, function and reason for the error, the file and line
     98 // where the error originated, plus potentially any context-specific
     99 // information about the error. |context| contains a pointer to user-supplied
    100 // data, which is currently unused.
    101 // If this callback returns a value <= 0, OpenSSL will stop processing the
    102 // error queue and return, otherwise it will continue calling this function
    103 // until all errors have been removed from the queue.
    104 int OpenSSLErrorCallback(const char* str, size_t len, void* context) {
    105   DVLOG(1) << "\t" << base::StringPiece(str, len);
    106   return 1;
    107 }
    108 
    109 }  // namespace
    110 
    111 void EnsureOpenSSLInit() {
    112   (void)OpenSSLInitSingleton::GetInstance();
    113 }
    114 
    115 void ClearOpenSSLERRStack(const tracked_objects::Location& location) {
    116   if (logging::DEBUG_MODE && VLOG_IS_ON(1)) {
    117     int error_num = ERR_peek_error();
    118     if (error_num == 0)
    119       return;
    120 
    121     std::string message;
    122     location.Write(true, true, &message);
    123     DVLOG(1) << "OpenSSL ERR_get_error stack from " << message;
    124     ERR_print_errors_cb(&OpenSSLErrorCallback, NULL);
    125   } else {
    126     ERR_clear_error();
    127   }
    128 }
    129 
    130 }  // namespace crypto
    131