138a52bd3SEd Maste /* 238a52bd3SEd Maste * Copyright (c) 1996, David Mazieres <dm@uun.org> 338a52bd3SEd Maste * Copyright (c) 2008, Damien Miller <djm@openbsd.org> 438a52bd3SEd Maste * Copyright (c) 2013, Markus Friedl <markus@openbsd.org> 538a52bd3SEd Maste * 638a52bd3SEd Maste * Permission to use, copy, modify, and distribute this software for any 738a52bd3SEd Maste * purpose with or without fee is hereby granted, provided that the above 838a52bd3SEd Maste * copyright notice and this permission notice appear in all copies. 938a52bd3SEd Maste * 1038a52bd3SEd Maste * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 1138a52bd3SEd Maste * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 1238a52bd3SEd Maste * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 1338a52bd3SEd Maste * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 1438a52bd3SEd Maste * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 1538a52bd3SEd Maste * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 1638a52bd3SEd Maste * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 1738a52bd3SEd Maste */ 1838a52bd3SEd Maste 1938a52bd3SEd Maste #include "includes.h" 2038a52bd3SEd Maste 2138a52bd3SEd Maste #ifndef SSH_RANDOM_DEV 2238a52bd3SEd Maste # define SSH_RANDOM_DEV "/dev/urandom" 2338a52bd3SEd Maste #endif /* SSH_RANDOM_DEV */ 2438a52bd3SEd Maste 2538a52bd3SEd Maste #include <sys/types.h> 2638a52bd3SEd Maste #ifdef HAVE_SYS_RANDOM_H 2738a52bd3SEd Maste # include <sys/random.h> 2838a52bd3SEd Maste #endif 2938a52bd3SEd Maste 3038a52bd3SEd Maste #include <fcntl.h> 3138a52bd3SEd Maste #include <stdlib.h> 3238a52bd3SEd Maste #include <string.h> 3338a52bd3SEd Maste #include <unistd.h> 3438a52bd3SEd Maste #ifdef WITH_OPENSSL 3538a52bd3SEd Maste #include <openssl/rand.h> 3638a52bd3SEd Maste #include <openssl/err.h> 3738a52bd3SEd Maste #endif 3838a52bd3SEd Maste 3938a52bd3SEd Maste #include "log.h" 4038a52bd3SEd Maste 4138a52bd3SEd Maste int 4238a52bd3SEd Maste _ssh_compat_getentropy(void *s, size_t len) 4338a52bd3SEd Maste { 4438a52bd3SEd Maste #ifdef WITH_OPENSSL 4538a52bd3SEd Maste if (RAND_bytes(s, len) <= 0) 4638a52bd3SEd Maste fatal("Couldn't obtain random bytes (error 0x%lx)", 4738a52bd3SEd Maste (unsigned long)ERR_get_error()); 4838a52bd3SEd Maste #else 4938a52bd3SEd Maste int fd, save_errno; 5038a52bd3SEd Maste ssize_t r; 5138a52bd3SEd Maste size_t o = 0; 5238a52bd3SEd Maste 53*f374ba41SEd Maste #ifdef HAVE_GETENTROPY 54*f374ba41SEd Maste if (r = getentropy(s, len) == 0) 55*f374ba41SEd Maste return 0; 56*f374ba41SEd Maste #endif /* HAVE_GETENTROPY */ 5738a52bd3SEd Maste #ifdef HAVE_GETRANDOM 5838a52bd3SEd Maste if ((r = getrandom(s, len, 0)) > 0 && (size_t)r == len) 5938a52bd3SEd Maste return 0; 6038a52bd3SEd Maste #endif /* HAVE_GETRANDOM */ 6138a52bd3SEd Maste 6238a52bd3SEd Maste if ((fd = open(SSH_RANDOM_DEV, O_RDONLY)) == -1) { 6338a52bd3SEd Maste save_errno = errno; 6438a52bd3SEd Maste /* Try egd/prngd before giving up. */ 6538a52bd3SEd Maste if (seed_from_prngd(s, len) == 0) 6638a52bd3SEd Maste return 0; 6738a52bd3SEd Maste fatal("Couldn't open %s: %s", SSH_RANDOM_DEV, 6838a52bd3SEd Maste strerror(save_errno)); 6938a52bd3SEd Maste } 7038a52bd3SEd Maste while (o < len) { 7138a52bd3SEd Maste r = read(fd, (u_char *)s + o, len - o); 7238a52bd3SEd Maste if (r < 0) { 7338a52bd3SEd Maste if (errno == EAGAIN || errno == EINTR || 7438a52bd3SEd Maste errno == EWOULDBLOCK) 7538a52bd3SEd Maste continue; 7638a52bd3SEd Maste fatal("read %s: %s", SSH_RANDOM_DEV, strerror(errno)); 7738a52bd3SEd Maste } 7838a52bd3SEd Maste o += r; 7938a52bd3SEd Maste } 8038a52bd3SEd Maste close(fd); 8138a52bd3SEd Maste #endif /* WITH_OPENSSL */ 8238a52bd3SEd Maste return 0; 8338a52bd3SEd Maste } 84