Mercurial > dropbear
view svr-main.c @ 1306:34e6127ef02e
merge fixes from PuTTY import.c
toint() from misc.c
(revids are from hggit conversion)
changeset: 4620:60a336a6c85c
user: Simon Tatham <[email protected]>
date: Thu Feb 25 20:26:33 2016 +0000
files: import.c
description:
Fix potential segfaults in reading OpenSSH's ASN.1 key format.
The length coming back from ber_read_id_len might have overflowed, so
treat it as potentially negative. Also, while I'm here, accumulate it
inside ber_read_id_len as an unsigned, so as to avoid undefined
behaviour on integer overflow, and toint() it before return.
Thanks to Hanno Böck for spotting this, with the aid of AFL.
(cherry picked from commit 5b7833cd474a24ec098654dcba8cb9509f3bf2c1)
Conflicts:
import.c
(cherry-picker's note: resolving the conflict involved removing an
entire section of the original commit which fixed ECDSA code not
present on this branch)
changeset: 4619:9c6c638d98d8
user: Simon Tatham <[email protected]>
date: Sun Jul 14 10:45:54 2013 +0000
files: import.c ssh.c sshdss.c sshpubk.c sshrsa.c
description:
Tighten up a lot of casts from unsigned to int which are read by one
of the GET_32BIT macros and then used as length fields. Missing bounds
checks against zero have been added, and also I've introduced a helper
function toint() which casts from unsigned to int in such a way as to
avoid C undefined behaviour, since I'm not sure I trust compilers any
more to do the obviously sensible thing.
[originally from svn r9918]
changeset: 4618:3957829f24d3
user: Simon Tatham <[email protected]>
date: Mon Jul 08 22:36:04 2013 +0000
files: import.c sshdss.c sshrsa.c
description:
Add an assortment of extra safety checks.
[originally from svn r9896]
changeset: 4617:2cddee0bce12
user: Jacob Nevins <[email protected]>
date: Wed Dec 07 00:24:45 2005 +0000
files: import.c
description:
Institutional failure to memset() things pointed at rather than pointers.
Things should now be zeroed and memory not leaked. Spotted by Brant Thomsen.
[originally from svn r6476]
changeset: 4616:24ac78a9c71d
user: Simon Tatham <[email protected]>
date: Wed Feb 11 13:58:27 2004 +0000
files: import.c
description:
Jacob's last-minute testing found a couple of trivial bugs in
import.c, and my attempts to reproduce them in cmdgen found another
one there :-)
[originally from svn r3847]
changeset: 4615:088d39a73db0
user: Simon Tatham <[email protected]>
date: Thu Jan 22 18:52:49 2004 +0000
files: import.c
description:
Placate some gcc warnings.
[originally from svn r3761]
changeset: 4614:e4288bad4d93
parent: 1758:108b8924593d
user: Simon Tatham <[email protected]>
date: Fri Oct 03 21:21:23 2003 +0000
files: import.c
description:
My ASN.1 decoder returned wrong IDs for anything above 0x1E! Good
job it's never had to yet. Ahem.
[originally from svn r3479]
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Tue, 12 Jul 2016 23:00:01 +0800 |
parents | 9169e4e7cbee |
children | 750ec4ec4cbe |
line wrap: on
line source
/* * Dropbear - a SSH2 server * * Copyright (c) 2002-2006 Matt Johnston * All rights reserved. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include "includes.h" #include "dbutil.h" #include "session.h" #include "buffer.h" #include "signkey.h" #include "runopts.h" #include "dbrandom.h" #include "crypto_desc.h" static size_t listensockets(int *sock, size_t sockcount, int *maxfd); static void sigchld_handler(int dummy); static void sigsegv_handler(int); static void sigintterm_handler(int fish); #ifdef INETD_MODE static void main_inetd(void); #endif #ifdef NON_INETD_MODE static void main_noinetd(void); #endif static void commonsetup(void); #if defined(DBMULTI_dropbear) || !defined(DROPBEAR_MULTI) #if defined(DBMULTI_dropbear) && defined(DROPBEAR_MULTI) int dropbear_main(int argc, char ** argv) #else int main(int argc, char ** argv) #endif { _dropbear_exit = svr_dropbear_exit; _dropbear_log = svr_dropbear_log; disallow_core(); /* get commandline options */ svr_getopts(argc, argv); #ifdef INETD_MODE /* service program mode */ if (svr_opts.inetdmode) { main_inetd(); /* notreached */ } #endif #ifdef NON_INETD_MODE main_noinetd(); /* notreached */ #endif dropbear_exit("Compiled without normal mode, can't run without -i\n"); return -1; } #endif #ifdef INETD_MODE static void main_inetd() { char *host, *port = NULL; /* Set up handlers, syslog, seed random */ commonsetup(); /* In case our inetd was lax in logging source addresses */ get_socket_address(0, NULL, NULL, &host, &port, 0); dropbear_log(LOG_INFO, "Child connection from %s:%s", host, port); m_free(host); m_free(port); /* Don't check the return value - it may just fail since inetd has * already done setsid() after forking (xinetd on Darwin appears to do * this */ setsid(); /* Start service program * -1 is a dummy childpipe, just something we can close() without * mattering. */ svr_session(0, -1); /* notreached */ } #endif /* INETD_MODE */ #ifdef NON_INETD_MODE static void main_noinetd() { fd_set fds; unsigned int i, j; int val; int maxsock = -1; int listensocks[MAX_LISTEN_ADDR]; size_t listensockcount = 0; FILE *pidfile = NULL; int childpipes[MAX_UNAUTH_CLIENTS]; char * preauth_addrs[MAX_UNAUTH_CLIENTS]; int childsock; int childpipe[2]; /* Note: commonsetup() must happen before we daemon()ise. Otherwise daemon() will chdir("/"), and we won't be able to find local-dir hostkeys. */ commonsetup(); /* sockets to identify pre-authenticated clients */ for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) { childpipes[i] = -1; } memset(preauth_addrs, 0x0, sizeof(preauth_addrs)); /* Set up the listening sockets */ listensockcount = listensockets(listensocks, MAX_LISTEN_ADDR, &maxsock); if (listensockcount == 0) { dropbear_exit("No listening ports available."); } for (i = 0; i < listensockcount; i++) { FD_SET(listensocks[i], &fds); } /* fork */ if (svr_opts.forkbg) { int closefds = 0; #ifndef DEBUG_TRACE if (!opts.usingsyslog) { closefds = 1; } #endif if (daemon(0, closefds) < 0) { dropbear_exit("Failed to daemonize: %s", strerror(errno)); } } /* should be done after syslog is working */ if (svr_opts.forkbg) { dropbear_log(LOG_INFO, "Running in background"); } else { dropbear_log(LOG_INFO, "Not backgrounding"); } /* create a PID file so that we can be killed easily */ pidfile = fopen(svr_opts.pidfile, "w"); if (pidfile) { fprintf(pidfile, "%d\n", getpid()); fclose(pidfile); } /* incoming connection select loop */ for(;;) { FD_ZERO(&fds); /* listening sockets */ for (i = 0; i < listensockcount; i++) { FD_SET(listensocks[i], &fds); } /* pre-authentication clients */ for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) { if (childpipes[i] >= 0) { FD_SET(childpipes[i], &fds); maxsock = MAX(maxsock, childpipes[i]); } } val = select(maxsock+1, &fds, NULL, NULL, NULL); if (exitflag) { unlink(svr_opts.pidfile); dropbear_exit("Terminated by signal"); } if (val == 0) { /* timeout reached - shouldn't happen. eh */ continue; } if (val < 0) { if (errno == EINTR) { continue; } dropbear_exit("Listening socket error"); } /* close fds which have been authed or closed - svr-auth.c handles * closing the auth sockets on success */ for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) { if (childpipes[i] >= 0 && FD_ISSET(childpipes[i], &fds)) { m_close(childpipes[i]); childpipes[i] = -1; m_free(preauth_addrs[i]); } } /* handle each socket which has something to say */ for (i = 0; i < listensockcount; i++) { size_t num_unauthed_for_addr = 0; size_t num_unauthed_total = 0; char *remote_host = NULL, *remote_port = NULL; pid_t fork_ret = 0; size_t conn_idx = 0; struct sockaddr_storage remoteaddr; socklen_t remoteaddrlen; if (!FD_ISSET(listensocks[i], &fds)) continue; remoteaddrlen = sizeof(remoteaddr); childsock = accept(listensocks[i], (struct sockaddr*)&remoteaddr, &remoteaddrlen); if (childsock < 0) { /* accept failed */ continue; } /* Limit the number of unauthenticated connections per IP */ getaddrstring(&remoteaddr, &remote_host, NULL, 0); num_unauthed_for_addr = 0; num_unauthed_total = 0; for (j = 0; j < MAX_UNAUTH_CLIENTS; j++) { if (childpipes[j] >= 0) { num_unauthed_total++; if (strcmp(remote_host, preauth_addrs[j]) == 0) { num_unauthed_for_addr++; } } else { /* a free slot */ conn_idx = j; } } if (num_unauthed_total >= MAX_UNAUTH_CLIENTS || num_unauthed_for_addr >= MAX_UNAUTH_PER_IP) { goto out; } seedrandom(); if (pipe(childpipe) < 0) { TRACE(("error creating child pipe")) goto out; } #ifdef DEBUG_NOFORK fork_ret = 0; #else fork_ret = fork(); #endif if (fork_ret < 0) { dropbear_log(LOG_WARNING, "Error forking: %s", strerror(errno)); goto out; } addrandom((void*)&fork_ret, sizeof(fork_ret)); if (fork_ret > 0) { /* parent */ childpipes[conn_idx] = childpipe[0]; m_close(childpipe[1]); preauth_addrs[conn_idx] = remote_host; remote_host = NULL; } else { /* child */ #ifdef DEBUG_FORKGPROF extern void _start(void), etext(void); monstartup((u_long)&_start, (u_long)&etext); #endif /* DEBUG_FORKGPROF */ getaddrstring(&remoteaddr, NULL, &remote_port, 0); dropbear_log(LOG_INFO, "Child connection from %s:%s", remote_host, remote_port); m_free(remote_host); m_free(remote_port); #ifndef DEBUG_NOFORK if (setsid() < 0) { dropbear_exit("setsid: %s", strerror(errno)); } #endif /* make sure we close sockets */ for (j = 0; j < listensockcount; j++) { m_close(listensocks[j]); } m_close(childpipe[0]); /* start the session */ svr_session(childsock, childpipe[1]); /* don't return */ dropbear_assert(0); } out: /* This section is important for the parent too */ m_close(childsock); if (remote_host) { m_free(remote_host); } } } /* for(;;) loop */ /* don't reach here */ } #endif /* NON_INETD_MODE */ /* catch + reap zombie children */ static void sigchld_handler(int UNUSED(unused)) { struct sigaction sa_chld; const int saved_errno = errno; while(waitpid(-1, NULL, WNOHANG) > 0) {} sa_chld.sa_handler = sigchld_handler; sa_chld.sa_flags = SA_NOCLDSTOP; sigemptyset(&sa_chld.sa_mask); if (sigaction(SIGCHLD, &sa_chld, NULL) < 0) { dropbear_exit("signal() error"); } errno = saved_errno; } /* catch any segvs */ static void sigsegv_handler(int UNUSED(unused)) { fprintf(stderr, "Aiee, segfault! You should probably report " "this as a bug to the developer\n"); _exit(EXIT_FAILURE); } /* catch ctrl-c or sigterm */ static void sigintterm_handler(int UNUSED(unused)) { exitflag = 1; } /* Things used by inetd and non-inetd modes */ static void commonsetup() { struct sigaction sa_chld; #ifndef DISABLE_SYSLOG if (opts.usingsyslog) { startsyslog(PROGNAME); } #endif /* set up cleanup handler */ if (signal(SIGINT, sigintterm_handler) == SIG_ERR || #ifndef DEBUG_VALGRIND signal(SIGTERM, sigintterm_handler) == SIG_ERR || #endif signal(SIGPIPE, SIG_IGN) == SIG_ERR) { dropbear_exit("signal() error"); } /* catch and reap zombie children */ sa_chld.sa_handler = sigchld_handler; sa_chld.sa_flags = SA_NOCLDSTOP; sigemptyset(&sa_chld.sa_mask); if (sigaction(SIGCHLD, &sa_chld, NULL) < 0) { dropbear_exit("signal() error"); } if (signal(SIGSEGV, sigsegv_handler) == SIG_ERR) { dropbear_exit("signal() error"); } crypto_init(); /* Now we can setup the hostkeys - needs to be after logging is on, * otherwise we might end up blatting error messages to the socket */ load_all_hostkeys(); seedrandom(); } /* Set up listening sockets for all the requested ports */ static size_t listensockets(int *socks, size_t sockcount, int *maxfd) { unsigned int i, n; char* errstring = NULL; size_t sockpos = 0; int nsock; TRACE(("listensockets: %d to try", svr_opts.portcount)) for (i = 0; i < svr_opts.portcount; i++) { TRACE(("listening on '%s:%s'", svr_opts.addresses[i], svr_opts.ports[i])) nsock = dropbear_listen(svr_opts.addresses[i], svr_opts.ports[i], &socks[sockpos], sockcount - sockpos, &errstring, maxfd); if (nsock < 0) { dropbear_log(LOG_WARNING, "Failed listening on '%s': %s", svr_opts.ports[i], errstring); m_free(errstring); continue; } for (n = 0; n < (unsigned int)nsock; n++) { int sock = socks[sockpos + n]; set_sock_priority(sock, DROPBEAR_PRIO_LOWDELAY); #ifdef DROPBEAR_SERVER_TCP_FAST_OPEN set_listen_fast_open(sock); #endif } sockpos += nsock; } return sockpos; }