// Copyright (c) 2011 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 "crypto/openssl_util.h"
#include <openssl/err.h>
#include <openssl/ssl.h>
#include "base/logging.h"
#include "base/memory/scoped_vector.h"
#include "base/memory/singleton.h"
#include "base/string_piece.h"
#include "base/synchronization/lock.h"
namespace crypto {
namespace {
unsigned long CurrentThreadId() {
return static_cast<unsigned long>(base::PlatformThread::CurrentId());
}
// Singleton for initializing and cleaning up the OpenSSL library.
class OpenSSLInitSingleton {
public:
static OpenSSLInitSingleton* GetInstance() {
// We allow the SSL environment to leak for multiple reasons:
// - it is used from a non-joinable worker thread that is not stopped on
// shutdown, hence may still be using OpenSSL library after the AtExit
// runner has completed.
// - There are other OpenSSL related singletons (e.g. the client socket
// context) who's cleanup depends on the global environment here, but
// we can't control the order the AtExit handlers will run in so
// allowing the global environment to leak at least ensures it is
// available for those other singletons to reliably cleanup.
return Singleton<OpenSSLInitSingleton,
LeakySingletonTraits<OpenSSLInitSingleton> >::get();
}
private:
friend struct DefaultSingletonTraits<OpenSSLInitSingleton>;
OpenSSLInitSingleton() {
SSL_load_error_strings();
SSL_library_init();
OpenSSL_add_all_algorithms();
int num_locks = CRYPTO_num_locks();
locks_.reserve(num_locks);
for (int i = 0; i < num_locks; ++i)
locks_.push_back(new base::Lock());
CRYPTO_set_locking_callback(LockingCallback);
CRYPTO_set_id_callback(CurrentThreadId);
}
~OpenSSLInitSingleton() {
CRYPTO_set_locking_callback(NULL);
EVP_cleanup();
ERR_free_strings();
}
static void LockingCallback(int mode, int n, const char* file, int line) {
OpenSSLInitSingleton::GetInstance()->OnLockingCallback(mode, n, file, line);
}
void OnLockingCallback(int mode, int n, const char* file, int line) {
CHECK_LT(static_cast<size_t>(n), locks_.size());
if (mode & CRYPTO_LOCK)
locks_[n]->Acquire();
else
locks_[n]->Release();
}
// These locks are used and managed by OpenSSL via LockingCallback().
ScopedVector<base::Lock> locks_;
DISALLOW_COPY_AND_ASSIGN(OpenSSLInitSingleton);
};
// Callback routine for OpenSSL to print error messages. |str| is a
// NULL-terminated string of length |len| containing diagnostic information
// such as the library, function and reason for the error, the file and line
// where the error originated, plus potentially any context-specific
// information about the error. |context| contains a pointer to user-supplied
// data, which is currently unused.
// If this callback returns a value <= 0, OpenSSL will stop processing the
// error queue and return, otherwise it will continue calling this function
// until all errors have been removed from the queue.
int OpenSSLErrorCallback(const char* str, size_t len, void* context) {
DVLOG(1) << "\t" << base::StringPiece(str, len);
return 1;
}
} // namespace
void EnsureOpenSSLInit() {
(void)OpenSSLInitSingleton::GetInstance();
}
void ClearOpenSSLERRStack(const tracked_objects::Location& location) {
if (logging::DEBUG_MODE && VLOG_IS_ON(1)) {
int error_num = ERR_peek_error();
if (error_num == 0)
return;
std::string message;
location.Write(true, true, &message);
DVLOG(1) << "OpenSSL ERR_get_error stack from " << message;
ERR_print_errors_cb(&OpenSSLErrorCallback, NULL);
} else {
ERR_clear_error();
}
}
} // namespace crypto