2 * Copyright (c) 2001 Damien Miller. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/types.h>
30 #include <sys/socket.h>
35 #include <netinet/in.h>
36 #include <arpa/inet.h>
42 #include <stddef.h> /* for offsetof */
44 #include <openssl/rand.h>
45 #include <openssl/crypto.h>
46 #include <openssl/err.h>
48 #include "openbsd-compat/openssl-compat.h"
54 #include "pathnames.h"
59 * Portable OpenSSH PRNG seeding:
60 * If OpenSSL has not "internally seeded" itself (e.g. pulled data from
61 * /dev/random), then collect RANDOM_SEED_SIZE bytes of randomness from
64 #ifndef OPENSSL_PRNG_ONLY
66 #define RANDOM_SEED_SIZE 48
69 * Collect 'len' bytes of entropy into 'buf' from PRNGD/EGD daemon
70 * listening either on 'tcp_port', or via Unix domain socket at *
72 * Either a non-zero tcp_port or a non-null socket_path must be
74 * Returns 0 on success, -1 on error
77 get_random_bytes_prngd(unsigned char *buf, int len,
78 unsigned short tcp_port, char *socket_path)
80 int fd, addr_len, rval, errors;
82 struct sockaddr_storage addr;
83 struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr;
84 struct sockaddr_un *addr_un = (struct sockaddr_un *)&addr;
88 if (socket_path == NULL && tcp_port == 0)
89 fatal("You must specify a port or a socket");
90 if (socket_path != NULL &&
91 strlen(socket_path) >= sizeof(addr_un->sun_path))
92 fatal("Random pool path is too long");
93 if (len <= 0 || len > 255)
94 fatal("Too many bytes (%d) to read from PRNGD", len);
96 memset(&addr, '\0', sizeof(addr));
99 addr_in->sin_family = AF_INET;
100 addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
101 addr_in->sin_port = htons(tcp_port);
102 addr_len = sizeof(*addr_in);
104 addr_un->sun_family = AF_UNIX;
105 strlcpy(addr_un->sun_path, socket_path,
106 sizeof(addr_un->sun_path));
107 addr_len = offsetof(struct sockaddr_un, sun_path) +
108 strlen(socket_path) + 1;
111 old_sigpipe = mysignal(SIGPIPE, SIG_IGN);
116 fd = socket(addr.ss_family, SOCK_STREAM, 0);
118 error("Couldn't create socket: %s", strerror(errno));
122 if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) {
124 error("Couldn't connect to PRNGD port %d: %s",
125 tcp_port, strerror(errno));
127 error("Couldn't connect to PRNGD socket \"%s\": %s",
128 addr_un->sun_path, strerror(errno));
133 /* Send blocking read request to PRNGD */
137 if (atomicio(vwrite, fd, msg, sizeof(msg)) != sizeof(msg)) {
138 if (errno == EPIPE && errors < 10) {
143 error("Couldn't write to PRNGD socket: %s",
148 if (atomicio(read, fd, buf, len) != (size_t)len) {
149 if (errno == EPIPE && errors < 10) {
154 error("Couldn't read from PRNGD socket: %s",
161 mysignal(SIGPIPE, old_sigpipe);
168 seed_from_prngd(unsigned char *buf, size_t bytes)
171 debug("trying egd/prngd port %d", PRNGD_PORT);
172 if (get_random_bytes_prngd(buf, bytes, PRNGD_PORT, NULL) == 0)
176 debug("trying egd/prngd socket %s", PRNGD_SOCKET);
177 if (get_random_bytes_prngd(buf, bytes, 0, PRNGD_SOCKET) == 0)
184 rexec_send_rng_seed(Buffer *m)
186 u_char buf[RANDOM_SEED_SIZE];
188 if (RAND_bytes(buf, sizeof(buf)) <= 0) {
189 error("Couldn't obtain random bytes (error %ld)",
191 buffer_put_string(m, "", 0);
193 buffer_put_string(m, buf, sizeof(buf));
197 rexec_recv_rng_seed(Buffer *m)
202 buf = buffer_get_string_ret(m, &len);
204 debug3("rexec_recv_rng_seed: seeding rng with %u bytes", len);
205 RAND_add(buf, len, len);
208 #endif /* OPENSSL_PRNG_ONLY */
213 #ifndef OPENSSL_PRNG_ONLY
214 unsigned char buf[RANDOM_SEED_SIZE];
216 if (!ssh_compatible_openssl(OPENSSL_VERSION_NUMBER, SSLeay()))
217 fatal("OpenSSL version mismatch. Built against %lx, you "
218 "have %lx", (u_long)OPENSSL_VERSION_NUMBER, SSLeay());
220 #ifndef OPENSSL_PRNG_ONLY
221 if (RAND_status() == 1) {
222 debug3("RNG is ready, skipping seeding");
226 if (seed_from_prngd(buf, sizeof(buf)) == -1)
227 fatal("Could not obtain seed from PRNGd");
228 RAND_add(buf, sizeof(buf), sizeof(buf));
229 memset(buf, '\0', sizeof(buf));
231 #endif /* OPENSSL_PRNG_ONLY */
232 if (RAND_status() != 1)
233 fatal("PRNG is not seeded");
236 #else /* WITH_OPENSSL */
238 /* Handled in arc4random() */
244 #endif /* WITH_OPENSSL */