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/*
* Copyright (c) 2001 Damien Miller. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
#include <sys/types.h>
#include <sys/socket.h>
#ifdef HAVE_SYS_UN_H
# include <sys/un.h>
#endif
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stddef.h> /* for offsetof */
#include "atomicio.h"
#include "misc.h"
#include "log.h"
#if defined(PRNGD_PORT) || defined(PRNGD_SOCKET)
/*
* EGD/PRNGD interface.
*
* Collect 'len' bytes of entropy into 'buf' from PRNGD/EGD daemon
* listening either on 'tcp_port', or via Unix domain socket at *
* 'socket_path'.
* Either a non-zero tcp_port or a non-null socket_path must be
* supplied.
* Returns 0 on success, -1 on error
*/
static int
get_random_bytes_prngd(unsigned char *buf, int len,
unsigned short tcp_port, char *socket_path)
{
int fd, addr_len, rval, errors;
u_char msg[2];
struct sockaddr_storage addr;
struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr;
struct sockaddr_un *addr_un = (struct sockaddr_un *)&addr;
sshsig_t old_sigpipe;
/* Sanity checks */
if (socket_path == NULL && tcp_port == 0)
fatal("You must specify a port or a socket");
if (socket_path != NULL &&
strlen(socket_path) >= sizeof(addr_un->sun_path))
fatal("Random pool path is too long");
if (len <= 0 || len > 255)
fatal("Too many bytes (%d) to read from PRNGD", len);
memset(&addr, '\0', sizeof(addr));
if (tcp_port != 0) {
addr_in->sin_family = AF_INET;
addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
addr_in->sin_port = htons(tcp_port);
addr_len = sizeof(*addr_in);
} else {
addr_un->sun_family = AF_UNIX;
strlcpy(addr_un->sun_path, socket_path,
sizeof(addr_un->sun_path));
addr_len = offsetof(struct sockaddr_un, sun_path) +
strlen(socket_path) + 1;
}
old_sigpipe = ssh_signal(SIGPIPE, SIG_IGN);
errors = 0;
rval = -1;
reopen:
fd = socket(addr.ss_family, SOCK_STREAM, 0);
if (fd == -1) {
error("Couldn't create socket: %s", strerror(errno));
goto done;
}
if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) {
if (tcp_port != 0) {
error("Couldn't connect to PRNGD port %d: %s",
tcp_port, strerror(errno));
} else {
error("Couldn't connect to PRNGD socket \"%s\": %s",
addr_un->sun_path, strerror(errno));
}
goto done;
}
/* Send blocking read request to PRNGD */
msg[0] = 0x02;
msg[1] = len;
if (atomicio(vwrite, fd, msg, sizeof(msg)) != sizeof(msg)) {
if (errno == EPIPE && errors < 10) {
close(fd);
errors++;
goto reopen;
}
error("Couldn't write to PRNGD socket: %s",
strerror(errno));
goto done;
}
if (atomicio(read, fd, buf, len) != (size_t)len) {
if (errno == EPIPE && errors < 10) {
close(fd);
errors++;
goto reopen;
}
error("Couldn't read from PRNGD socket: %s",
strerror(errno));
goto done;
}
rval = 0;
done:
ssh_signal(SIGPIPE, old_sigpipe);
if (fd != -1)
close(fd);
return rval;
}
#endif /* PRNGD_PORT || PRNGD_SOCKET */
int
seed_from_prngd(unsigned char *buf, size_t bytes)
{
#ifdef PRNGD_PORT
debug("trying egd/prngd port %d", PRNGD_PORT);
if (get_random_bytes_prngd(buf, bytes, PRNGD_PORT, NULL) == 0)
return 0;
#endif
#ifdef PRNGD_SOCKET
debug("trying egd/prngd socket %s", PRNGD_SOCKET);
if (get_random_bytes_prngd(buf, bytes, 0, PRNGD_SOCKET) == 0)
return 0;
#endif
return -1;
}
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