size_t RNG_SystemRNG(void *dest, size_t maxLen)
{
HMODULE hModule;
RtlGenRandomFn pRtlGenRandom;
CryptAcquireContextAFn pCryptAcquireContextA;
CryptReleaseContextFn pCryptReleaseContext;
CryptGenRandomFn pCryptGenRandom;
HCRYPTPROV hCryptProv;
size_t bytes = 0;
usedWindowsPRNG = PR_FALSE;
hModule = LoadLibrary("advapi32.dll");
if (hModule == NULL) {
return rng_systemFromNoise(dest,maxLen);
}
pRtlGenRandom = (RtlGenRandomFn)
GetProcAddress(hModule, "SystemFunction036");
if (pRtlGenRandom) {
if (pRtlGenRandom(dest, maxLen)) {
bytes = maxLen;
usedWindowsPRNG = PR_TRUE;
} else {
bytes = rng_systemFromNoise(dest,maxLen);
}
goto done;
}
pCryptAcquireContextA = (CryptAcquireContextAFn)
GetProcAddress(hModule, "CryptAcquireContextA");
pCryptReleaseContext = (CryptReleaseContextFn)
GetProcAddress(hModule, "CryptReleaseContext");
pCryptGenRandom = (CryptGenRandomFn)
GetProcAddress(hModule, "CryptGenRandom");
if (!pCryptAcquireContextA || !pCryptReleaseContext || !pCryptGenRandom) {
bytes = rng_systemFromNoise(dest,maxLen);
goto done;
}
if (pCryptAcquireContextA(&hCryptProv, NULL, NULL,
PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
if (pCryptGenRandom(hCryptProv, maxLen, dest)) {
bytes = maxLen;
usedWindowsPRNG = PR_TRUE;
}
pCryptReleaseContext(hCryptProv, 0);
}
if (bytes == 0) {
bytes = rng_systemFromNoise(dest,maxLen);
}
done:
FreeLibrary(hModule);
return bytes;
}
size_t RNG_SystemRNG(void *dest, size_t maxLen)
{
FILE *file;
size_t bytes;
size_t fileBytes = 0;
unsigned char *buffer = dest;
file = fopen("/dev/urandom", "r");
if (file == NULL) {
return rng_systemFromNoise(dest, maxLen);
}
/* Set buffering mode to unbuffered I/O to avoid reading more bytes
* than we need from /dev/urandom. */
setvbuf(file, NULL, _IONBF, 0);
while (maxLen > fileBytes) {
bytes = maxLen - fileBytes;
bytes = fread(buffer, 1, bytes, file);
if (bytes == 0)
break;
fileBytes += bytes;
buffer += bytes;
}
fclose(file);
if (fileBytes != maxLen) {
PORT_SetError(SEC_ERROR_NEED_RANDOM); /* system RNG failed */
fileBytes = 0;
}
return fileBytes;
}
size_t RNG_SystemRNG(void *dest, size_t maxLen)
{
FILE *file;
size_t bytes;
size_t fileBytes = 0;
unsigned char *buffer = dest;
file = fopen("/dev/urandom", "r");
if (file == NULL) {
return rng_systemFromNoise(dest, maxLen);
}
while (maxLen > fileBytes) {
bytes = maxLen - fileBytes;
bytes = fread(buffer, 1, bytes, file);
if (bytes == 0)
break;
fileBytes += bytes;
buffer += bytes;
}
fclose(file);
if (fileBytes != maxLen) {
PORT_SetError(SEC_ERROR_NEED_RANDOM); /* system RNG failed */
fileBytes = 0;
}
return fileBytes;
}
size_t RNG_SystemRNG(void *dest, size_t maxLen)
{
FILE *file;
int fd;
int bytes;
size_t fileBytes = 0;
unsigned char *buffer = dest;
file = fopen("/dev/urandom", "r");
if (file == NULL) {
return rng_systemFromNoise(dest, maxLen);
}
/* Read from the underlying file descriptor directly to bypass stdio
* buffering and avoid reading more bytes than we need from /dev/urandom.
* NOTE: we can't use fread with unbuffered I/O because fread may return
* EOF in unbuffered I/O mode on Android.
*/
fd = fileno(file);
while (maxLen > fileBytes) {
bytes = maxLen - fileBytes;
bytes = read(fd, buffer, bytes);
if (bytes <= 0)
break;
fileBytes += bytes;
buffer += bytes;
}
fclose(file);
if (fileBytes != maxLen) {
PORT_SetError(SEC_ERROR_NEED_RANDOM); /* system RNG failed */
fileBytes = 0;
}
return fileBytes;
}
/*
* The Windows CE and Windows Mobile FIPS Security Policy, page 13,
* (http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp825.pdf)
* says CeGenRandom is the right function to call for creating a seed
* for a random number generator.
*/
size_t RNG_SystemRNG(void *dest, size_t maxLen)
{
size_t bytes = 0;
usedWindowsPRNG = PR_FALSE;
if (CeGenRandom(maxLen, dest)) {
bytes = maxLen;
usedWindowsPRNG = PR_TRUE;
}
if (bytes == 0) {
bytes = rng_systemFromNoise(dest,maxLen);
}
return bytes;
}
size_t RNG_SystemRNG(void *dest, size_t maxLen)
{
return rng_systemFromNoise(dest,maxLen);
}
