M2_SETI/A1/TP/axtls-code/axtlswrap/axtlswrap.c

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2022-11-28 11:40:47 +01:00
/*
* Copyright (c) 2009, Steve Bennett
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of the axTLS project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 COPYRIGHT OWNER OR
* CONTRIBUTORS 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.
*/
/*
* sslwrap re-implemented with axTLS - a way to wrap an existing webserver
* with axTLS.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <sys/poll.h>
#include "os_port.h"
#include "ssl.h"
/* If nothing is received or sent in this many seconds, give up */
static int opt_timeout = 60;
static int opt_verbose = 0;
int main(int argc, char *argv[])
{
int log_opts = LOG_PERROR;
int fd[2]; /* output from child */
int df[2]; /* input to child */
int pid;
unsigned char *readbuf;
int readlen;
SSL_CTX *ssl_ctx;
SSL *ssl;
/* This relies on stdin and stdout being one and the same */
int sslfd = fileno(stdin);
while (argc > 2 && argv[1][0] == '-')
{
if (argc > 3 && strcmp(argv[1], "-t") == 0)
{
opt_timeout = atoi(argv[2]);
argv += 2;
argc -= 2;
continue;
}
if (strcmp(argv[1], "-q") == 0)
{
log_opts = 0;
argv++;
argc--;
continue;
}
if (strcmp(argv[1], "-v") == 0)
{
opt_verbose++;
argv++;
argc--;
continue;
}
}
if (argc < 2)
{
fprintf(stderr, "Usage: axtlswrap [-v] [-q] "
"[-t timeout] command ...\n");
return 1;
}
if (access(argv[1], X_OK) != 0)
{
fprintf(stderr, "Not an executabled: %s\n", argv[1]);
return 1;
}
openlog("axtlswrap", LOG_PID | log_opts, LOG_DAEMON);
/* Create an SSL context with the required options */
ssl_ctx = ssl_ctx_new(opt_verbose > 1 ?
SSL_DISPLAY_STATES | SSL_DISPLAY_CERTS : 0, 1);
if (ssl_ctx == NULL)
{
syslog(LOG_ERR, "Failed to create SSL ctx");
return 1;
}
/* And create an ssl session attached to sslfd */
ssl = ssl_server_new(ssl_ctx, sslfd);
if (ssl == NULL)
{
syslog(LOG_ERR, "Failed to create SSL connection");
return 1;
}
/* Get past the handshaking */
while ((readlen = ssl_read(ssl, &readbuf)) == SSL_OK)
{
/* Still handshaking */
}
if (readlen < 0)
{
syslog(LOG_ERR, "SSL handshake failed: %d", readlen);
return 1;
}
if (opt_verbose)
{
syslog(LOG_INFO, "SSL handshake OK");
}
/* Looks OK, we have data, so fork the child and start */
if (pipe(fd) < 0 || pipe(df) < 0)
{
syslog(LOG_ERR, "pipe failed: %m");
return 1;
}
/* Give some indication to the child that we are running SSL
* It would be possible to provide other details
* too. Perhaps as in: http://httpd.apache.org/docs/2.0/mod/mod_ssl.html
*/
setenv("SSL_PROTOCOL", "TLSv1", 1);
#ifndef NOMMU
if (opt_verbose)
{
pid = fork();
}
else
#endif
pid = vfork();
if (pid < 0)
{
syslog(LOG_ERR, "vfork failed: %m");
return 1;
}
if (pid > 0)
{
/* This is the parent */
unsigned char writebuf[4096];
int writelen = 0;
struct pollfd pfd[3];
int timeout_count = 0;
int cwfd = df[1]; /* write to child */
int crfd = fd[0]; /* read from child */
int child_alive = 1;
/* Don't die on SIGPIPE */
signal(SIGPIPE, SIG_IGN);
close(df[0]);
close(fd[1]);
pfd[0].fd = sslfd;
pfd[1].fd = cwfd;
pfd[2].fd = crfd;
/* While the child is alive or there is something to return... */
while (child_alive || writelen > 0)
{
/* Work out what to read and what to write */
int ret;
pfd[0].events = 0;
pfd[0].revents = 0;
/* Only want to read ssl data if there is nothing else to do */
if (readlen == 0)
{
/* can read ssl data */
pfd[0].events |= POLLIN;
}
if (writelen > 0)
{
/* can write ssl data - will block to do this */
pfd[0].events |= POLLOUT;
}
pfd[1].events = 0;
pfd[1].revents = 0;
if (child_alive && readlen > 0)
{
pfd[1].events |= POLLOUT;
}
pfd[2].events = 0;
pfd[2].revents = 0;
if (child_alive && writelen == 0)
{
pfd[2].events |= POLLIN;
}
/* Timeout after 1 second so we can increment timeout_count */
ret = poll(pfd, 3, 1000);
if (ret < 0)
{
if (errno != EAGAIN)
{
/* Kill off the child */
kill(pid, SIGTERM);
break;
}
continue;
}
if (ret == 0)
{
if (++timeout_count >= opt_timeout)
{
/* Kill off the child */
kill(pid, SIGTERM);
break;
}
continue;
}
timeout_count = 0;
if (pfd[2].revents & POLLNVAL)
{
/* REVISIT: This can probably be removed */
syslog(LOG_ERR, "Child closed output pipe");
child_alive = 0;
}
else if (pfd[2].revents & POLLIN)
{
/* Can read from (3) */
writelen = read(crfd, writebuf, sizeof(writebuf));
if (writelen <= 0)
{
if (writelen < 0)
{
syslog(LOG_WARNING, "Failed to read from child: len=%d",
writelen);
}
break;
}
}
else if ((pfd[2].revents & POLLHUP) && kill(pid, 0) == 0)
{
if (opt_verbose)
{
syslog(LOG_INFO, "Child died and pipe gave POLLHUP");
}
child_alive = 0;
}
if (writelen > 0)
{
const unsigned char *pt = writebuf;
while (writelen > 0)
{
ret = ssl_write(ssl, pt, writelen);
if (ret <= 0)
{
syslog(LOG_WARNING, "Failed to write ssl: ret=%d", ret);
/* Kill off the child now */
kill(pid, SIGTERM);
writelen = -1;
break;
}
else
{
pt += ret;
writelen -= ret;
}
}
if (writelen < 0)
{
break;
}
}
else if (pfd[0].revents & POLLIN)
{
readlen = ssl_read(ssl, &readbuf);
if (readlen <= 0 && opt_verbose)
{
syslog(LOG_INFO, "ssl_read() returned %d", readlen);
}
if (readlen < 0)
{
/* Kill off the child */
kill(pid, SIGTERM);
break;
}
}
if (pfd[1].revents & POLLNVAL)
{
/* REVISIT: This can probably be removed */
syslog(LOG_ERR, "Child closed input pipe");
readlen = -1;
child_alive = 0;
}
else if (pfd[1].revents & POLLOUT)
{
const unsigned char *pt = readbuf;
while (readlen > 0)
{
int len = write(cwfd, pt, readlen);
if (len <= 0)
{
syslog(LOG_WARNING, "Failed to write to child: len=%d",
len);
break;
}
readlen -= len;
pt += len;
}
}
}
ssl_free(ssl);
#if 0
fprintf(stderr, "[%d] SSL done: timeout_count=%d, readlen=%d, writelen=%d, child_alive=%d\n",
getpid(), timeout_count, readlen, writelen, child_alive);
#endif
return 0;
}
/* Child */
close(df[1]);
close(fd[0]);
dup2(df[0],0);
dup2(fd[1],1);
close(df[0]);
close(fd[1]);
execv(argv[1], argv + 1);
_exit(1);
}