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 */