/****************
* Note: Using a level of 0 should never block and better add nothing
* to the pool. This is easy to accomplish with /dev/urandom.
*/
static int
gather_random( void (*add)(const void*, size_t, int), int requester,
size_t length, int level )
{
static int fd_urandom = -1;
static int fd_random = -1;
int fd;
int n;
int warn=0;
byte buffer[768];
if( level >= 2 ) {
if( fd_random == -1 )
fd_random = open_device( NAME_OF_DEV_RANDOM, 8 );
fd = fd_random;
}
else {
/* this will also be used for elve 0 but by using /dev/urandom
* we can be sure that oit will never block. */
if( fd_urandom == -1 )
fd_urandom = open_device( NAME_OF_DEV_URANDOM, 9 );
fd = fd_urandom;
}
#if 0
#ifdef HAVE_DEV_RANDOM_IOCTL
g10_log_info("entropy count of %d is %lu\n", fd, get_entropy_count(fd) );
#endif
#endif
while( length ) {
fd_set rfds;
struct timeval tv;
int rc;
FD_ZERO(&rfds);
FD_SET(fd, &rfds);
tv.tv_sec = 3;
tv.tv_usec = 0;
if( !(rc=select(fd+1, &rfds, NULL, NULL, &tv)) ) {
if( !warn )
#ifdef IS_MODULE
fprintf(stderr,
#else
tty_printf(
#endif
_("\n"
"Not enough random bytes available. Please do some other work to give\n"
"the OS a chance to collect more entropy! (Need %d more bytes)\n"), length );
warn = 1;
continue;
}
else if( rc == -1 ) {
#ifdef IS_MODULE
fprintf(stderr,
#else
tty_printf(
#endif
"select() error: %s\n", strerror(errno));
continue;
}
static void
slow_gatherer_windowsNT( void (*add)(const void*, size_t, int), int requester )
{
static int is_initialized = 0;
static NETSTATISTICSGET pNetStatisticsGet = NULL;
static NETAPIBUFFERSIZE pNetApiBufferSize = NULL;
static NETAPIBUFFERFREE pNetApiBufferFree = NULL;
static int is_workstation = 1;
static int cbPerfData = PERFORMANCE_BUFFER_SIZE;
PERF_DATA_BLOCK *pPerfData;
HANDLE hDevice, hNetAPI32 = NULL;
DWORD dwSize, status;
int nDrive;
if ( !is_initialized ) {
HKEY hKey;
if ( debug_me )
log_debug ("rndw32#slow_gatherer_nt: init toolkit\n" );
/* Find out whether this is an NT server or workstation if necessary */
if (RegOpenKeyEx (HKEY_LOCAL_MACHINE,
"SYSTEM\\CurrentControlSet\\Control\\ProductOptions",
0, KEY_READ, &hKey) == ERROR_SUCCESS) {
BYTE szValue[32];
dwSize = sizeof (szValue);
if ( debug_me )
log_debug ("rndw32#slow_gatherer_nt: check product options\n" );
status = RegQueryValueEx (hKey, "ProductType", 0, NULL,
szValue, &dwSize);
if (status == ERROR_SUCCESS
&& ascii_strcasecmp (szValue, "WinNT")) {
/* Note: There are (at least) three cases for ProductType:
* WinNT = NT Workstation, ServerNT = NT Server, LanmanNT =
* NT Server acting as a Domain Controller */
is_workstation = 0;
if ( debug_me )
log_debug ("rndw32: this is a NT server\n");
}
RegCloseKey (hKey);
}
/* Initialize the NetAPI32 function pointers if necessary */
if ( (hNetAPI32 = LoadLibrary ("NETAPI32.DLL")) ) {
if ( debug_me )
log_debug ("rndw32#slow_gatherer_nt: netapi32 loaded\n" );
pNetStatisticsGet = (NETSTATISTICSGET) GetProcAddress (hNetAPI32,
"NetStatisticsGet");
pNetApiBufferSize = (NETAPIBUFFERSIZE) GetProcAddress (hNetAPI32,
"NetApiBufferSize");
pNetApiBufferFree = (NETAPIBUFFERFREE) GetProcAddress (hNetAPI32,
"NetApiBufferFree");
if ( !pNetStatisticsGet
|| !pNetApiBufferSize || !pNetApiBufferFree ) {
FreeLibrary (hNetAPI32);
hNetAPI32 = NULL;
g10_log_debug ("rndw32: No NETAPI found\n" );
}
}
is_initialized = 1;
}
/* Get network statistics. Note: Both NT Workstation and NT Server by
* default will be running both the workstation and server services. The
* heuristic below is probably useful though on the assumption that the
* majority of the network traffic will be via the appropriate service.
* In any case the network statistics return almost no randomness */
{ LPBYTE lpBuffer;
if (hNetAPI32 && !pNetStatisticsGet (NULL,
is_workstation ? L"LanmanWorkstation" :
L"LanmanServer", 0, 0, &lpBuffer) ) {
if ( debug_me )
log_debug ("rndw32#slow_gatherer_nt: get netstats\n" );
pNetApiBufferSize (lpBuffer, &dwSize);
(*add) ( lpBuffer, dwSize,requester );
pNetApiBufferFree (lpBuffer);
}
}
/* Get disk I/O statistics for all the hard drives */
for (nDrive = 0;; nDrive++) {
char diskPerformance[SIZEOF_DISK_PERFORMANCE_STRUCT];
char szDevice[50];
/* Check whether we can access this device */
sprintf (szDevice, "\\\\.\\PhysicalDrive%d", nDrive);
hDevice = CreateFile (szDevice, 0, FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL, OPEN_EXISTING, 0, NULL);
if (hDevice == INVALID_HANDLE_VALUE)
break;
/* Note: This only works if you have turned on the disk performance
* counters with 'diskperf -y'. These counters are off by default */
if (DeviceIoControl (hDevice, IOCTL_DISK_PERFORMANCE, NULL, 0,
diskPerformance, SIZEOF_DISK_PERFORMANCE_STRUCT,
&dwSize, NULL))
{
if ( debug_me )
log_debug ("rndw32#slow_gatherer_nt: iostats drive %d\n",
nDrive );
(*add) (diskPerformance, dwSize, requester );
}
else {
log_info ("NOTE: you should run 'diskperf -y' "
"to enable the disk statistics\n");
}
CloseHandle (hDevice);
}
#if 0 /* we don't need this in GnuPG */
/* Wait for any async keyset driver binding to complete. You may be
* wondering what this call is doing here... the reason it's necessary is
* because RegQueryValueEx() will hang indefinitely if the async driver
* bind is in progress. The problem occurs in the dynamic loading and
* linking of driver DLL's, which work as follows:
*
* hDriver = LoadLibrary( DRIVERNAME );
* pFunction1 = ( TYPE_FUNC1 ) GetProcAddress( hDriver, NAME_FUNC1 );
* pFunction2 = ( TYPE_FUNC1 ) GetProcAddress( hDriver, NAME_FUNC2 );
*
* If RegQueryValueEx() is called while the GetProcAddress()'s are in
* progress, it will hang indefinitely. This is probably due to some
* synchronisation problem in the NT kernel where the GetProcAddress()
* calls affect something like a module reference count or function
* reference count while RegQueryValueEx() is trying to take a snapshot
* of the statistics, which include the reference counts. Because of
* this, we have to wait until any async driver bind has completed
* before we can call RegQueryValueEx() */
waitSemaphore (SEMAPHORE_DRIVERBIND);
#endif
/* Get information from the system performance counters. This can take
* a few seconds to do. In some environments the call to
* RegQueryValueEx() can produce an access violation at some random time
* in the future, adding a short delay after the following code block
* makes the problem go away. This problem is extremely difficult to
* reproduce, I haven't been able to get it to occur despite running it
* on a number of machines. The best explanation for the problem is that
* on the machine where it did occur, it was caused by an external driver
* or other program which adds its own values under the
* HKEY_PERFORMANCE_DATA key. The NT kernel calls the required external
* modules to map in the data, if there's a synchronisation problem the
* external module would write its data at an inappropriate moment,
* causing the access violation. A low-level memory checker indicated
* that ExpandEnvironmentStrings() in KERNEL32.DLL, called an
* interminable number of calls down inside RegQueryValueEx(), was
* overwriting memory (it wrote twice the allocated size of a buffer to a
* buffer allocated by the NT kernel). This may be what's causing the
* problem, but since it's in the kernel there isn't much which can be
* done.
*
* In addition to these problems the code in RegQueryValueEx() which
* estimates the amount of memory required to return the performance
* counter information isn't very accurate, since it always returns a
* worst-case estimate which is usually nowhere near the actual amount
* required. For example it may report that 128K of memory is required,
* but only return 64K of data */
if (getenv("GNUPG_RNDW32_NOPERF"))
{
static int shown;
if (!shown)
{
shown = 1;
g10_log_info ("note: get performance data has been disabled\n");
}
}
else
{ pPerfData = xmalloc (cbPerfData);
for (;;) {
dwSize = cbPerfData;
if ( debug_me )
log_debug ("rndw32#slow_gatherer_nt: get perf data\n" );
status = RegQueryValueEx (HKEY_PERFORMANCE_DATA, "Global", NULL,
NULL, (LPBYTE) pPerfData, &dwSize);
if (status == ERROR_SUCCESS) {
if (!memcmp (pPerfData->Signature, L"PERF", 8)) {
(*add) ( pPerfData, dwSize, requester );
}
else
g10_log_debug ( "rndw32: no PERF signature\n");
break;
}
else if (status == ERROR_MORE_DATA) {
cbPerfData += PERFORMANCE_BUFFER_STEP;
pPerfData = xrealloc (pPerfData, cbPerfData);
}
else {
g10_log_debug ( "rndw32: get performance data problem\n");
break;
}
}
xfree (pPerfData);
}
/* Although this isn't documented in the Win32 API docs, it's necessary
to explicitly close the HKEY_PERFORMANCE_DATA key after use (it's
implicitly opened on the first call to RegQueryValueEx()). If this
isn't done then any system components which provide performance data
can't be removed or changed while the handle remains active */
RegCloseKey (HKEY_PERFORMANCE_DATA);
}