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