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C_Initialize may be called by multiple threads 

While trying to setup an OpenSC context, the global_locking
and detect cards, it is possible that multiple threads may
call C_Initialize. The current code tries to prevent this using
"if (context == NULL)"  but this is not a mutex, and
multiple threads may endup overwrite contexts and global locking and
cause additional problems, with pcsc and segfault.

FireFox appears to do this see #2032

The PR adds a mutex or Critical section to make sure only one
thread creates the context sets the global_locking  and does
the initial detect cards, etc.

This allows the global_lock (if requested) to be setup
which is then used for other calls.

All but the first call to C_Initialize will return with CKR_OK,
others will return CKR_CRYPTOKI_ALREADY_INITIALIZED.

 Date:      Mon Jan 11 12:47:12 2021 -0600
 Changes to be committed:
	modified:   src/pkcs11/pkcs11-global.c
This commit is contained in:
Doug Engert 2021-01-11 12:47:12 -06:00 committed by Frank Morgner
parent d369965a7f
commit 1b4e9f1d4a
1 changed files with 25 additions and 0 deletions
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25
src/pkcs11/pkcs11-global.c
View File

@ -61,6 +61,11 @@ extern CK_FUNCTION_LIST_3_0 pkcs11_function_list_3_0;
#if defined(HAVE_PTHREAD)
/* mutex used to control C_Initilize creation of mutexes */
static pthread_mutex_t c_initialize_m = PTHREAD_MUTEX_INITIALIZER;
#define C_INITIALIZE_M_LOCK pthread_mutex_lock(&c_initialize_m);
#define C_INITIALIZE_M_UNLOCK pthread_mutex_unlock(&c_initialize_m);
CK_RV mutex_create(void **mutex)
{
pthread_mutex_t *m;
@ -101,6 +106,9 @@ static CK_C_INITIALIZE_ARGS _def_locks = {
#define HAVE_OS_LOCKING
#elif defined(_WIN32)
CRITICAL_SECTION c_initialize_cs = {0};
#define C_INITIALIZE_M_LOCK EnterCriticalSection(&c_initialize_cs);
#define C_INITIALIZE_M_UNLOCK LeaveCriticalSection(&c_initialize_cs);
CK_RV mutex_create(void **mutex)
{
@ -141,6 +149,10 @@ static CK_C_INITIALIZE_ARGS _def_locks = {
#endif
#else /* PKCS11_THREAD_LOCKING */
#define C_INITIALIZE_M_LOCK
#define C_INITIALIZE_M_UNLOCK
#endif /* PKCS11_THREAD_LOCKING */
static CK_C_INITIALIZE_ARGS_PTR global_locking;
@ -221,6 +233,9 @@ __attribute__((constructor))
#endif
int module_init()
{
#ifdef _WIN32
InitializeCriticalSection(&c_initialize_cs);
#endif
sc_notify_init();
return 1;
}
@ -236,6 +251,9 @@ int module_close()
#endif
#ifdef ENABLE_OPENPACE
EAC_cleanup();
#endif
#ifdef _WIN32
DeleteCriticalSection(&c_initialize_cs);
#endif
return 1;
}
@ -283,8 +301,12 @@ CK_RV C_Initialize(CK_VOID_PTR pInitArgs)
in_finalize = 0;
#endif
/* protect from multiple threads tryng to setup locking */
C_INITIALIZE_M_LOCK
if (context != NULL) {
sc_log(context, "C_Initialize(): Cryptoki already initialized\n");
C_INITIALIZE_M_UNLOCK
return CKR_CRYPTOKI_ALREADY_INITIALIZED;
}
@ -336,6 +358,9 @@ out:
sc_pkcs11_free_lock();
}
/* protect from multiple threads tryng to setup locking */
C_INITIALIZE_M_UNLOCK
return rv;
}