xenocara/app/xdm/prngc.c
2010-03-28 09:33:02 +00:00

191 lines
4.9 KiB
C

/*
* Copyright (c) 1995,1999 Theo de Raadt. All rights reserved.
* Copyright (c) 2001-2002 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 <sys/types.h>
#include <sys/socket.h>
#include <X11/Xos.h>
#ifndef X_NO_SYS_UN
# include <sys/un.h>
#endif
#include <netinet/in.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "dm_auth.h"
#include "dm_error.h"
#ifndef INADDR_LOOPBACK
# define INADDR_LOOPBACK 0x7F000001U
#endif
static ssize_t atomicio(ssize_t (*)(int, void *, size_t), int, void *, size_t);
#ifndef offsetof
# define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif
/*
* 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
*/
int
get_prngd_bytes(char *buf, int len,
unsigned short tcp_port, char *socket_path)
{
int fd, addr_len, rval, errors;
char msg[2];
struct sockaddr *addr;
struct sockaddr_in addr_in;
struct sockaddr_un addr_un;
int af;
void (*old_sigpipe)(int);
/* Sanity checks */
if (socket_path == NULL && tcp_port == 0) {
LogError("get_random_prngd: "
"You must specify a port or a socket\n");
return -1;
}
if (socket_path != NULL &&
strlen(socket_path) >= sizeof(addr_un.sun_path)) {
LogError("get_random_prngd: Random pool path is too long\n");
return -1;
}
if (len > 255) {
LogError("get_random_prngd: "
"Too many bytes to read from PRNGD\n");
return -1;
}
memset(&addr_in, '\0', sizeof(addr));
if (tcp_port != 0) {
af = 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);
addr = (struct sockaddr *)&addr_in;
} else {
af = addr_un.sun_family = AF_UNIX;
strncpy(addr_un.sun_path, socket_path,
sizeof(addr_un.sun_path));
addr_len = offsetof(struct sockaddr_un, sun_path) +
strlen(socket_path) + 1;
addr = (struct sockaddr *)&addr_un;
}
old_sigpipe = signal(SIGPIPE, SIG_IGN);
errors = 0;
rval = -1;
reopen:
fd = socket(af, SOCK_STREAM, 0);
if (fd == -1) {
LogInfo("Couldn't create socket: %s\n", strerror(errno));
goto done;
}
if (connect(fd, (struct sockaddr*)addr, addr_len) == -1) {
if (af == AF_INET) {
LogInfo("Couldn't connect to PRNGD port %d: %s\n",
tcp_port, strerror(errno));
} else {
LogInfo("Couldn't connect to PRNGD socket"
" \"%s\": %s\n",
addr_un.sun_path, strerror(errno));
}
goto done;
}
/* Send blocking read request to PRNGD */
msg[0] = 0x02;
msg[1] = len;
if (atomicio(write, fd, msg, sizeof(msg)) != sizeof(msg)) {
if (errno == EPIPE && errors < 10) {
close(fd);
errors++;
goto reopen;
}
LogInfo("Couldn't write to PRNGD socket: %s\n",
strerror(errno));
goto done;
}
if (atomicio(read, fd, buf, len) != len) {
if (errno == EPIPE && errors < 10) {
close(fd);
errors++;
goto reopen;
}
LogInfo("Couldn't read from PRNGD socket: %s\n",
strerror(errno));
goto done;
}
rval = 0;
done:
signal(SIGPIPE, old_sigpipe);
if (fd != -1)
close(fd);
return rval;
}
/*
* ensure all of data on socket comes through. f==read || f==write
*/
static ssize_t
atomicio(ssize_t (*f)(int, void *, size_t), int fd, void *_s, size_t n)
{
char *s = _s;
ssize_t res, pos = 0;
while (n > pos) {
res = (f) (fd, s + pos, n - pos);
switch (res) {
case -1:
#ifdef EWOULDBLOCK
if (errno == EINTR || errno == EAGAIN
|| errno == EWOULDBLOCK)
#else
if (errno == EINTR || errno == EAGAIN)
#endif
continue;
case 0:
return (res);
default:
pos += res;
}
}
return (pos);
}