BOOL WINAPI CryptGenRandom(HCRYPTPROV phProv, DWORD dwLen, BYTE *pbBuffer)
{
IBuffer *buffer = NULL;
HRESULT hr = ICryptographicBufferStatics_GenerateRandom(phProv, dwLen, &buffer);
if (FAILED(hr)) {
return FALSE;
}
UINT32 olength;
unsigned char *rnd = NULL;
hr = ICryptographicBufferStatics_CopyToByteArray(phProv, buffer, &olength, (BYTE**)&rnd);
if (FAILED(hr)) {
IBuffer_Release(buffer);
return FALSE;
}
memcpy(pbBuffer, rnd, dwLen);
IBuffer_Release(buffer);
return TRUE;
}
void vlc_rand_bytes (void *buf, size_t len)
{
size_t count = len;
uint8_t *p_buf = (uint8_t *)buf;
/* fill buffer with pseudo-random data */
while (count > 0)
{
unsigned int val;
val = rand();
if (count < sizeof (val))
{
memcpy (p_buf, &val, count);
break;
}
memcpy (p_buf, &val, sizeof (val));
count -= sizeof (val);
p_buf += sizeof (val);
}
#if VLC_WINSTORE_APP
static const WCHAR *className = L"Windows.Security.Cryptography.CryptographicBuffer";
const UINT32 clen = wcslen(className);
HSTRING hClassName = NULL;
HSTRING_HEADER header;
HRESULT hr = WindowsCreateStringReference(className, clen, &header, &hClassName);
if (hr) {
WindowsDeleteString(hClassName);
return;
}
ICryptographicBufferStatics *cryptoStatics = NULL;
hr = RoGetActivationFactory(hClassName, &IID_ICryptographicBufferStatics, (void**)&cryptoStatics);
WindowsDeleteString(hClassName);
if (hr)
return;
IBuffer *buffer = NULL;
hr = ICryptographicBufferStatics_GenerateRandom(cryptoStatics, len, &buffer);
if (hr) {
ICryptographicBufferStatics_Release(cryptoStatics);
return;
}
UINT32 olength;
unsigned char *rnd = NULL;
hr = ICryptographicBufferStatics_CopyToByteArray(cryptoStatics, buffer, &olength, (BYTE**)&rnd);
memcpy(buf, rnd, len);
IBuffer_Release(buffer);
ICryptographicBufferStatics_Release(cryptoStatics);
#else
HCRYPTPROV hProv;
/* acquire default encryption context */
if( CryptAcquireContext(
&hProv, // Variable to hold returned handle.
NULL, // Use default key container.
MS_DEF_PROV, // Use default CSP.
PROV_RSA_FULL, // Type of provider to acquire.
CRYPT_VERIFYCONTEXT) ) // Flag values
{
/* fill buffer with pseudo-random data, intial buffer content
is used as auxillary random seed */
CryptGenRandom(hProv, len, buf);
CryptReleaseContext(hProv, 0);
}
#endif /* VLC_WINSTORE_APP */
}
