| 783 | } |
| 784 | |
| 785 | int csprng_bytes(void *buf, size_t len, MAYBE_UNUSED unsigned flags) |
| 786 | { |
| 787 | #if defined(HAVE_ARC4RANDOM) || defined(HAVE_ARC4RANDOM_LIBBSD) |
| 788 | /* This function never returns an error. */ |
| 789 | arc4random_buf(buf, len); |
| 790 | return 0; |
| 791 | #elif defined(HAVE_GETRANDOM) |
| 792 | ssize_t res; |
| 793 | char *p = buf; |
| 794 | while (len) { |
| 795 | res = getrandom(p, len, 0); |
| 796 | if (res < 0) |
| 797 | return -1; |
| 798 | len -= res; |
| 799 | p += res; |
| 800 | } |
| 801 | return 0; |
| 802 | #elif defined(HAVE_GETENTROPY) |
| 803 | int res; |
| 804 | char *p = buf; |
| 805 | while (len) { |
| 806 | /* getentropy has a maximum size of 256 bytes. */ |
| 807 | size_t chunk = len < 256 ? len : 256; |
| 808 | res = getentropy(p, chunk); |
| 809 | if (res < 0) |
| 810 | return -1; |
| 811 | len -= chunk; |
| 812 | p += chunk; |
| 813 | } |
| 814 | return 0; |
| 815 | #elif defined(HAVE_RTLGENRANDOM) |
| 816 | if (!RtlGenRandom(buf, len)) |
| 817 | return -1; |
| 818 | return 0; |
| 819 | #elif defined(HAVE_OPENSSL_CSPRNG) |
| 820 | switch (RAND_pseudo_bytes(buf, len)) { |
| 821 | case 1: |
| 822 | return 0; |
| 823 | case 0: |
| 824 | if (flags & CSPRNG_BYTES_INSECURE) |
| 825 | return 0; |
| 826 | errno = EIO; |
| 827 | return -1; |
| 828 | default: |
| 829 | errno = ENOTSUP; |
| 830 | return -1; |
| 831 | } |
| 832 | #else |
| 833 | ssize_t res; |
| 834 | char *p = buf; |
| 835 | int fd, err; |
| 836 | fd = open("/dev/urandom", O_RDONLY); |
| 837 | if (fd < 0) |
| 838 | return -1; |
| 839 | while (len) { |
| 840 | res = xread(fd, p, len); |
| 841 | if (res < 0) { |
| 842 | err = errno; |