Mercurial > dropbear
view sshpty.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 | 523be406edc4 |
children |
line wrap: on
line source
/* * Dropbear - a SSH2 server * * Copied from OpenSSH-3.5p1 source, modified by Matt Johnston 2003 * * Author: Tatu Ylonen <[email protected]> * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland * All rights reserved * Allocating a pseudo-terminal, and making it the controlling tty. * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". */ /*RCSID("OpenBSD: sshpty.c,v 1.7 2002/06/24 17:57:20 deraadt Exp ");*/ #include "includes.h" #include "dbutil.h" #include "errno.h" #include "sshpty.h" /* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */ #if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY) #undef HAVE_DEV_PTMX #endif #ifdef HAVE_PTY_H # include <pty.h> #endif #if defined(USE_DEV_PTMX) && defined(HAVE_STROPTS_H) # include <stropts.h> #endif #ifndef O_NOCTTY #define O_NOCTTY 0 #endif /* * Allocates and opens a pty. Returns 0 if no pty could be allocated, or * nonzero if a pty was successfully allocated. On success, open file * descriptors for the pty and tty sides and the name of the tty side are * returned (the buffer must be able to hold at least 64 characters). */ int pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen) { #if defined(HAVE_OPENPTY) /* exists in recent (4.4) BSDs and OSF/1 */ char *name; int i; i = openpty(ptyfd, ttyfd, NULL, NULL, NULL); if (i < 0) { dropbear_log(LOG_WARNING, "pty_allocate: openpty: %.100s", strerror(errno)); return 0; } name = ttyname(*ttyfd); if (!name) { dropbear_exit("ttyname fails for openpty device"); } strlcpy(namebuf, name, namebuflen); /* possible truncation */ return 1; #else /* HAVE_OPENPTY */ #ifdef HAVE__GETPTY /* * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more * pty's automagically when needed */ char *slave; slave = _getpty(ptyfd, O_RDWR, 0622, 0); if (slave == NULL) { dropbear_log(LOG_WARNING, "pty_allocate: _getpty: %.100s", strerror(errno)); return 0; } strlcpy(namebuf, slave, namebuflen); /* Open the slave side. */ *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); if (*ttyfd < 0) { dropbear_log(LOG_WARNING, "pty_allocate error: ttyftd open error"); close(*ptyfd); return 0; } return 1; #else /* HAVE__GETPTY */ #if defined(USE_DEV_PTMX) /* * This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3 * also has bsd-style ptys, but they simply do not work.) * * Linux systems may have the /dev/ptmx device, but this code won't work. */ int ptm; char *pts; ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY); if (ptm < 0) { dropbear_log(LOG_WARNING, "pty_allocate: /dev/ptmx: %.100s", strerror(errno)); return 0; } if (grantpt(ptm) < 0) { dropbear_log(LOG_WARNING, "grantpt: %.100s", strerror(errno)); return 0; } if (unlockpt(ptm) < 0) { dropbear_log(LOG_WARNING, "unlockpt: %.100s", strerror(errno)); return 0; } pts = ptsname(ptm); if (pts == NULL) { dropbear_log(LOG_WARNING, "Slave pty side name could not be obtained."); } strlcpy(namebuf, pts, namebuflen); *ptyfd = ptm; /* Open the slave side. */ *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); if (*ttyfd < 0) { dropbear_log(LOG_ERR, "error opening pts %.100s: %.100s", namebuf, strerror(errno)); close(*ptyfd); return 0; } #if !defined(HAVE_CYGWIN) && defined(I_PUSH) /* * Push the appropriate streams modules, as described in Solaris pts(7). * HP-UX pts(7) doesn't have ttcompat module. */ if (ioctl(*ttyfd, I_PUSH, "ptem") < 0) { dropbear_log(LOG_WARNING, "ioctl I_PUSH ptem: %.100s", strerror(errno)); } if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0) { dropbear_log(LOG_WARNING, "ioctl I_PUSH ldterm: %.100s", strerror(errno)); } #ifndef __hpux if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0) { dropbear_log(LOG_WARNING, "ioctl I_PUSH ttcompat: %.100s", strerror(errno)); } #endif #endif return 1; #else /* USE_DEV_PTMX */ #ifdef HAVE_DEV_PTS_AND_PTC /* AIX-style pty code. */ const char *name; *ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY); if (*ptyfd < 0) { dropbear_log(LOG_ERR, "Could not open /dev/ptc: %.100s", strerror(errno)); return 0; } name = ttyname(*ptyfd); if (!name) { dropbear_exit("ttyname fails for /dev/ptc device"); } strlcpy(namebuf, name, namebuflen); *ttyfd = open(name, O_RDWR | O_NOCTTY); if (*ttyfd < 0) { dropbear_log(LOG_ERR, "Could not open pty slave side %.100s: %.100s", name, strerror(errno)); close(*ptyfd); return 0; } return 1; #else /* HAVE_DEV_PTS_AND_PTC */ /* BSD-style pty code. */ char buf[64]; int i; const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ"; const char *ptyminors = "0123456789abcdef"; int num_minors = strlen(ptyminors); int num_ptys = strlen(ptymajors) * num_minors; struct termios tio; for (i = 0; i < num_ptys; i++) { snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors], ptyminors[i % num_minors]); snprintf(namebuf, namebuflen, "/dev/tty%c%c", ptymajors[i / num_minors], ptyminors[i % num_minors]); *ptyfd = open(buf, O_RDWR | O_NOCTTY); if (*ptyfd < 0) { /* Try SCO style naming */ snprintf(buf, sizeof buf, "/dev/ptyp%d", i); snprintf(namebuf, namebuflen, "/dev/ttyp%d", i); *ptyfd = open(buf, O_RDWR | O_NOCTTY); if (*ptyfd < 0) { continue; } } /* Open the slave side. */ *ttyfd = open(namebuf, O_RDWR | O_NOCTTY); if (*ttyfd < 0) { dropbear_log(LOG_ERR, "pty_allocate: %.100s: %.100s", namebuf, strerror(errno)); close(*ptyfd); return 0; } /* set tty modes to a sane state for broken clients */ if (tcgetattr(*ptyfd, &tio) < 0) { dropbear_log(LOG_WARNING, "ptyallocate: tty modes failed: %.100s", strerror(errno)); } else { tio.c_lflag |= (ECHO | ISIG | ICANON); tio.c_oflag |= (OPOST | ONLCR); tio.c_iflag |= ICRNL; /* Set the new modes for the terminal. */ if (tcsetattr(*ptyfd, TCSANOW, &tio) < 0) { dropbear_log(LOG_WARNING, "Setting tty modes for pty failed: %.100s", strerror(errno)); } } return 1; } dropbear_log(LOG_WARNING, "Failed to open any /dev/pty?? devices"); return 0; #endif /* HAVE_DEV_PTS_AND_PTC */ #endif /* USE_DEV_PTMX */ #endif /* HAVE__GETPTY */ #endif /* HAVE_OPENPTY */ } /* Releases the tty. Its ownership is returned to root, and permissions to 0666. */ void pty_release(const char *tty_name) { if (chown(tty_name, (uid_t) 0, (gid_t) 0) < 0 && (errno != ENOENT)) { dropbear_log(LOG_ERR, "chown %.100s 0 0 failed: %.100s", tty_name, strerror(errno)); } if (chmod(tty_name, (mode_t) 0666) < 0 && (errno != ENOENT)) { dropbear_log(LOG_ERR, "chmod %.100s 0666 failed: %.100s", tty_name, strerror(errno)); } } /* Makes the tty the processes controlling tty and sets it to sane modes. */ void pty_make_controlling_tty(int *ttyfd, const char *tty_name) { int fd; #ifdef USE_VHANGUP void *old; #endif /* USE_VHANGUP */ /* Solaris has a problem with TIOCNOTTY for a bg process, so * we disable the signal which would STOP the process - matt */ signal(SIGTTOU, SIG_IGN); /* First disconnect from the old controlling tty. */ #ifdef TIOCNOTTY fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); if (fd >= 0) { (void) ioctl(fd, TIOCNOTTY, NULL); close(fd); } #endif /* TIOCNOTTY */ if (setsid() < 0) { dropbear_log(LOG_ERR, "setsid: %.100s", strerror(errno)); } /* * Verify that we are successfully disconnected from the controlling * tty. */ fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); if (fd >= 0) { dropbear_log(LOG_ERR, "Failed to disconnect from controlling tty.\n"); close(fd); } /* Make it our controlling tty. */ #ifdef TIOCSCTTY if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0) { dropbear_log(LOG_ERR, "ioctl(TIOCSCTTY): %.100s", strerror(errno)); } #endif /* TIOCSCTTY */ #ifdef HAVE_NEWS4 if (setpgrp(0,0) < 0) { dropbear_log(LOG_ERR, error("SETPGRP %s",strerror(errno))); } #endif /* HAVE_NEWS4 */ #ifdef USE_VHANGUP old = mysignal(SIGHUP, SIG_IGN); vhangup(); mysignal(SIGHUP, old); #endif /* USE_VHANGUP */ fd = open(tty_name, O_RDWR); if (fd < 0) { dropbear_log(LOG_ERR, "%.100s: %.100s", tty_name, strerror(errno)); } else { #ifdef USE_VHANGUP close(*ttyfd); *ttyfd = fd; #else /* USE_VHANGUP */ close(fd); #endif /* USE_VHANGUP */ } /* Verify that we now have a controlling tty. */ fd = open(_PATH_TTY, O_WRONLY); if (fd < 0) { dropbear_log(LOG_ERR, "open /dev/tty failed - could not set controlling tty: %.100s", strerror(errno)); } else { close(fd); } } /* Changes the window size associated with the pty. */ void pty_change_window_size(int ptyfd, int row, int col, int xpixel, int ypixel) { struct winsize w; w.ws_row = row; w.ws_col = col; w.ws_xpixel = xpixel; w.ws_ypixel = ypixel; (void) ioctl(ptyfd, TIOCSWINSZ, &w); } void pty_setowner(struct passwd *pw, const char *tty_name) { struct group *grp; gid_t gid; mode_t mode; struct stat st; /* Determine the group to make the owner of the tty. */ grp = getgrnam("tty"); if (grp) { gid = grp->gr_gid; mode = S_IRUSR | S_IWUSR | S_IWGRP; } else { gid = pw->pw_gid; mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH; } /* * Change owner and mode of the tty as required. * Warn but continue if filesystem is read-only and the uids match/ * tty is owned by root. */ if (stat(tty_name, &st)) { dropbear_exit("pty_setowner: stat(%.101s) failed: %.100s", tty_name, strerror(errno)); } if (st.st_uid != pw->pw_uid || st.st_gid != gid) { if (chown(tty_name, pw->pw_uid, gid) < 0) { if (errno == EROFS && (st.st_uid == pw->pw_uid || st.st_uid == 0)) { dropbear_log(LOG_ERR, "chown(%.100s, %u, %u) failed: %.100s", tty_name, (unsigned int)pw->pw_uid, (unsigned int)gid, strerror(errno)); } else { dropbear_exit("chown(%.100s, %u, %u) failed: %.100s", tty_name, (unsigned int)pw->pw_uid, (unsigned int)gid, strerror(errno)); } } } if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) { if (chmod(tty_name, mode) < 0) { if (errno == EROFS && (st.st_mode & (S_IRGRP | S_IROTH)) == 0) { dropbear_log(LOG_ERR, "chmod(%.100s, 0%o) failed: %.100s", tty_name, mode, strerror(errno)); } else { dropbear_exit("chmod(%.100s, 0%o) failed: %.100s", tty_name, mode, strerror(errno)); } } } }