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.
27 #include <sys/types.h>
28 #include <sys/socket.h>
33 #include <netinet/in.h>
34 #include <arpa/inet.h>
40 #include <stddef.h> /* for offsetof */
42 #include <openssl/rand.h>
43 #include <openssl/crypto.h>
44 #include <openssl/err.h>
46 #include "openbsd-compat/openssl-compat.h"
52 #include "pathnames.h"
57 * Portable OpenSSH PRNG seeding:
58 * If OpenSSL has not "internally seeded" itself (e.g. pulled data from
59 * /dev/random), then collect RANDOM_SEED_SIZE bytes of randomness from
62 #ifndef OPENSSL_PRNG_ONLY
64 #define RANDOM_SEED_SIZE 48
67 * Collect 'len' bytes of entropy into 'buf' from PRNGD/EGD daemon
68 * listening either on 'tcp_port', or via Unix domain socket at *
70 * Either a non-zero tcp_port or a non-null socket_path must be
72 * Returns 0 on success, -1 on error
75 get_random_bytes_prngd(unsigned char *buf
, int len
,
76 unsigned short tcp_port
, char *socket_path
)
78 int fd
, addr_len
, rval
, errors
;
80 struct sockaddr_storage addr
;
81 struct sockaddr_in
*addr_in
= (struct sockaddr_in
*)&addr
;
82 struct sockaddr_un
*addr_un
= (struct sockaddr_un
*)&addr
;
86 if (socket_path
== NULL
&& tcp_port
== 0)
87 fatal("You must specify a port or a socket");
88 if (socket_path
!= NULL
&&
89 strlen(socket_path
) >= sizeof(addr_un
->sun_path
))
90 fatal("Random pool path is too long");
91 if (len
<= 0 || len
> 255)
92 fatal("Too many bytes (%d) to read from PRNGD", len
);
94 memset(&addr
, '\0', sizeof(addr
));
97 addr_in
->sin_family
= AF_INET
;
98 addr_in
->sin_addr
.s_addr
= htonl(INADDR_LOOPBACK
);
99 addr_in
->sin_port
= htons(tcp_port
);
100 addr_len
= sizeof(*addr_in
);
102 addr_un
->sun_family
= AF_UNIX
;
103 strlcpy(addr_un
->sun_path
, socket_path
,
104 sizeof(addr_un
->sun_path
));
105 addr_len
= offsetof(struct sockaddr_un
, sun_path
) +
106 strlen(socket_path
) + 1;
109 old_sigpipe
= mysignal(SIGPIPE
, SIG_IGN
);
114 fd
= socket(addr
.ss_family
, SOCK_STREAM
, 0);
116 error("Couldn't create socket: %s", strerror(errno
));
120 if (connect(fd
, (struct sockaddr
*)&addr
, addr_len
) == -1) {
122 error("Couldn't connect to PRNGD port %d: %s",
123 tcp_port
, strerror(errno
));
125 error("Couldn't connect to PRNGD socket \"%s\": %s",
126 addr_un
->sun_path
, strerror(errno
));
131 /* Send blocking read request to PRNGD */
135 if (atomicio(vwrite
, fd
, msg
, sizeof(msg
)) != sizeof(msg
)) {
136 if (errno
== EPIPE
&& errors
< 10) {
141 error("Couldn't write to PRNGD socket: %s",
146 if (atomicio(read
, fd
, buf
, len
) != (size_t)len
) {
147 if (errno
== EPIPE
&& errors
< 10) {
152 error("Couldn't read from PRNGD socket: %s",
159 mysignal(SIGPIPE
, old_sigpipe
);
166 seed_from_prngd(unsigned char *buf
, size_t bytes
)
169 debug("trying egd/prngd port %d", PRNGD_PORT
);
170 if (get_random_bytes_prngd(buf
, bytes
, PRNGD_PORT
, NULL
) == 0)
174 debug("trying egd/prngd socket %s", PRNGD_SOCKET
);
175 if (get_random_bytes_prngd(buf
, bytes
, 0, PRNGD_SOCKET
) == 0)
182 rexec_send_rng_seed(Buffer
*m
)
184 u_char buf
[RANDOM_SEED_SIZE
];
186 if (RAND_bytes(buf
, sizeof(buf
)) <= 0) {
187 error("Couldn't obtain random bytes (error %ld)",
189 buffer_put_string(m
, "", 0);
191 buffer_put_string(m
, buf
, sizeof(buf
));
195 rexec_recv_rng_seed(Buffer
*m
)
200 buf
= buffer_get_string_ret(m
, &len
);
202 debug3("rexec_recv_rng_seed: seeding rng with %u bytes", len
);
203 RAND_add(buf
, len
, len
);
206 #endif /* OPENSSL_PRNG_ONLY */
211 #ifndef OPENSSL_PRNG_ONLY
212 unsigned char buf
[RANDOM_SEED_SIZE
];
214 if (!ssh_compatible_openssl(OPENSSL_VERSION_NUMBER
, SSLeay()))
215 fatal("OpenSSL version mismatch. Built against %lx, you "
216 "have %lx", (u_long
)OPENSSL_VERSION_NUMBER
, SSLeay());
218 #ifndef OPENSSL_PRNG_ONLY
219 if (RAND_status() == 1) {
220 debug3("RNG is ready, skipping seeding");
224 if (seed_from_prngd(buf
, sizeof(buf
)) == -1)
225 fatal("Could not obtain seed from PRNGd");
226 RAND_add(buf
, sizeof(buf
), sizeof(buf
));
227 memset(buf
, '\0', sizeof(buf
));
229 #endif /* OPENSSL_PRNG_ONLY */
230 if (RAND_status() != 1)
231 fatal("PRNG is not seeded");