我想生成许多ec密钥对。加快了这个过程,我重写了我的应用程序,使用多个线程来完成这项工作。以下是每个线程生成密钥的方式的代码片段:
(...)
EC_KEY* _ec_key = EC_KEY_new();
EC_GROUP* ec_group_new = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
const EC_GROUP* ec_group = ec_group_new;
if (!EC_KEY_set_group(ec_key,ec_group))
DieWithError("Error in initializeCrypto, EC_KEY_set_group failed!");
// Segfault at this position
if(!EC_KEY_generate_key(ec_key))
DieWithError ("Error in generateKeys, EC_KEY_generate_key failed!");
(...)
EC_GROUP_free(ec_group_new);
EC_KEY_free(ec_key);
乍一看好,一切似乎都运转良好。在i5 520m上使用四个线程,应用程序的运行速度提高了两倍。但是经过3-4次E6密钥生成后,它突然出现了段错误。如果我锁定EC_KEY_generate_key操作,则不再存在段错误,但使用多个线程的优势已经消失。现在我的问题。是否有可能将密钥的创建分成多个线程而不破坏内存?我没有使用谷歌找到任何信息。但SSL Docu没有提及有关线程安全的任何内容。任何帮助都非常感谢。 THX
答案 0 :(得分:4)
// Segfault at this position
if(!EC_KEY_generate_key(ec_key))
DieWithError ("Error in generateKeys, EC_KEY_generate_key failed!");
...
... But then after 3-4 E6 key generations it suddenly segfaults.
您正在使用OpenSSL的随机数生成器,而且它不是线程安全的。下面是来自第125行的cryptlib.c
。注意随机数生成器和椭圆曲线齿轮列表。
/* real #defines in crypto.h, keep these upto date */
static const char* const lock_names[CRYPTO_NUM_LOCKS] =
{
"<<ERROR>>",
"err",
"ex_data",
"x509",
"x509_info",
"x509_pkey",
"x509_crl",
"x509_req",
...
"ssl_ctx",
"ssl_session",
"ssl",
"ssl_method",
"rand",
"rand2",
...
"ecdsa",
"ec",
"ecdh",
"bn",
"ec_pre_comp",
...
};
您必须明确设置锁定。请参阅OpenSSL's threads(3)。
是否可以将密钥的创建拆分为多个线程而不会破坏内存?
是的,但您必须使用OpenSSL的锁定机制。
这是我的OpenSSL初始化例程在C ++中的样子。它初始化锁并设置回调。
pthread_mutex_t s_locks[CRYPTO_NUM_LOCKS] = { };
void Initialize()
{
static once_flag init;
std::call_once(init, []() {
// Standard OpenSSL library init
OPENSSL_no_config();
SSL_library_init();
SSL_load_error_strings();
OpenSSL_add_ssl_algorithms();
// Lock setup
LOCK_setup();
CALLBACK_setup();
});
}
void LOCK_setup()
{
ASSERT(CRYPTO_NUM_LOCKS == CRYPTO_num_locks());
if(CRYPTO_NUM_LOCKS != CRYPTO_num_locks())
throw runtime_error("CRYPTO_NUM_LOCKS mismatch");
for(unsigned i = 0; i < CRYPTO_NUM_LOCKS; ++i)
{
int rc = pthread_mutex_init(&s_locks[i], NULL);
ASSERT(rc == 0);
if(!(rc == 0))
throw runtime_error("pthread_mutex_init");
}
}
void CALLBACK_setup()
{
CRYPTO_set_id_callback(&ThreadIdFnc);
CRYPTO_set_locking_callback(&LockingFnc);
}
void LockingFnc(int mode, int idx, const char* file, int line)
{
ASSERT(mode == CRYPTO_LOCK || mode == CRYPTO_UNLOCK);
ASSERT(CRYPTO_NUM_LOCKS == CRYPTO_num_locks());
ASSERT(idx >= 0 && idx < CRYPTO_NUM_LOCKS);
if(!(idx >= 0 && idx < CRYPTO_NUM_LOCKS))
{
ostringstream oss;
oss << "LockingFnc: lock failed with bad index ";
oss << idx << ". File: " << (file ? file : "Unknown");
oss << ", line: " << line;
// Log oss.str()
return;
}
if((mode & CRYPTO_LOCK) == CRYPTO_LOCK)
{
int rc = pthread_mutex_lock(&s_locks[idx]);
int err = errno;
ASSERT(rc == 0);
if(!(rc == 0))
{
ostringstream oss;
oss << "LockingFnc: lock failed with error ";
oss << err << ". File: " << (file ? file : "Unknown");
oss << ", line: " << line;
throw runtime_error(oss.str());
}
}
else if((mode & CRYPTO_UNLOCK) == CRYPTO_UNLOCK)
{
int rc = pthread_mutex_unlock(&s_locks[idx]);
int err = errno;
ASSERT(rc == 0);
if(!(rc == 0))
{
ostringstream oss;
oss << "LockingFnc: unlock failed with error ";
oss << err << ". File: " << (file ? file : "Unknown");
oss << ", line: " << line;
throw runtime_error(oss.str());
}
}
}
unsigned long ThreadIdFnc()
{
#if defined(AC_OS_APPLE)
ASSERT(sizeof(unsigned long) >= sizeof(pid_t));
return static_cast<unsigned long>(pthread_mach_thread_np(pthread_self()));
#elif defined(AC_OS_STARNIX)
ASSERT(sizeof(unsigned long) >= sizeof(pid_t));
return static_cast<unsigned long>(gettid());
#else
# error "Unsupported platform"
#endif
}
如果您未使用libssl
,请放弃对SSL_library_init
的通话。所有libcrypto
需求都是OpenSSL_add_all_algorithms
初始化的调用。
但是,SSL文档没有提到有关线程安全的任何内容。
是的,文档有时会留下一些不足之处。我知道很多人正在通过OpenSSL Foundation运行wiki来改进它。 Matt Caswell在简单记录http://wiki.openssl.org/index.php/Elliptic_Curve_Cryptography的椭圆曲线中做了很多工作。他还负责POD文件和MAN页面。请记住,Matt没有编写任何代码 - 他只是为其他人编写代码。
有一个关于初始化的页面,但它没有锁的代码。它在我的TODO清单上。请参阅http://wiki.openssl.org/index.php/Library_Initialization。