| 1 | #define _BSD_SOURCE |
| 2 | #include <unistd.h> |
| 3 | #include <sys/random.h> |
| 4 | #include <pthread.h> |
| 5 | #include <errno.h> |
| 6 | |
| 7 | int getentropy(void *buffer, size_t len) |
| 8 | { |
| 9 | int cs, ret = 0; |
| 10 | char *pos = buffer; |
| 11 | |
| 12 | if (len > 256) { |
| 13 | errno = EIO; |
| 14 | return -1; |
| 15 | } |
| 16 | |
| 17 | pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); |
| 18 | |
| 19 | while (len) { |
| 20 | ret = getrandom(pos, len, 0); |
| 21 | if (ret < 0) { |
| 22 | if (errno == EINTR) continue; |
| 23 | else break; |
| 24 | } |
| 25 | pos += ret; |
| 26 | len -= ret; |
| 27 | ret = 0; |
| 28 | } |
| 29 | |
| 30 | pthread_setcancelstate(cs, 0); |
| 31 | |
| 32 | return ret; |
| 33 | } |