view debug.h @ 1930:299f4f19ba19

Add /usr/sbin and /sbin to default root PATH When dropbear is used in a very restricted environment (such as in a initrd), the default user shell is often also very restricted and doesn't take care of setting the PATH so the user ends up with the PATH set by dropbear. Unfortunately, dropbear always sets "/usr/bin:/bin" as default PATH even for the root user which should have /usr/sbin and /sbin too. For a concrete instance of this problem, see the "Remote Unlocking" section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/ It speaks of a bug in the initramfs script because it's written "blkid" instead of "/sbin/blkid"... this is just because the scripts from the initramfs do not expect to have a PATH without the sbin directories and because dropbear is not setting the PATH appropriately for the root user. I'm thus suggesting to use the attached patch to fix this misbehaviour (I did not test it, but it's easy enough). It might seem anecdotic but multiple Kali users have been bitten by this. From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403
author Raphael Hertzog <hertzog@debian.org>
date Mon, 09 Jul 2018 16:27:53 +0200
parents be236878efcf
children
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/*
 * Dropbear - a SSH2 server
 * 
 * Copyright (c) 2002,2003 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. */

#ifndef DROPBEAR_DEBUG_H_
#define DROPBEAR_DEBUG_H_

#include "includes.h"

/* Debugging */

/* Work well for valgrind - don't clear environment, be nicer with signals
 * etc. Don't use this normally, it might cause problems */
/* #define DEBUG_VALGRIND */

/* All functions writing to the cleartext payload buffer call
 * CHECKCLEARTOWRITE() before writing. This is only really useful if you're
 * attempting to track down a problem */
/*#define CHECKCLEARTOWRITE() assert(ses.writepayload->len == 0 && \
		ses.writepayload->pos == 0)*/

#ifndef CHECKCLEARTOWRITE
#define CHECKCLEARTOWRITE()
#endif

/* A couple of flags, not usually useful, and mightn't do anything */

/*#define DEBUG_KEXHASH*/
/*#define DEBUG_RSA*/

/* The level of TRACE() statements */
#define DROPBEAR_VERBOSE_LEVEL 4

#if DEBUG_TRACE
extern int debug_trace;
#endif

/* Enable debug trace levels.
   We can't use __VA_ARGS_ here because Dropbear supports 
   old ~C89 compilers */
/* Default is to discard output ... */
#define DEBUG1(X)
#define DEBUG2(X)
#define DEBUG3(X)
#define TRACE(X)
#define TRACE2(X)
/* ... unless DEBUG_TRACE is high enough */
#if (DEBUG_TRACE>=1)
#undef DEBUG1
#define DEBUG1(X) dropbear_trace1 X;
#endif
#if (DEBUG_TRACE>=2)
#undef DEBUG2
#define DEBUG2(X) dropbear_trace2 X;
#endif
#if (DEBUG_TRACE>=3)
#undef DEBUG3
#define DEBUG3(X) dropbear_trace3 X;
#endif
#if (DEBUG_TRACE>=4)
#undef TRACE
#define TRACE(X) dropbear_trace4 X;
#endif
#if (DEBUG_TRACE>=5)
#undef TRACE2
#define TRACE2(X) dropbear_trace5 X;
#endif

/* To debug with GDB it is easier to run with no forking of child processes.
   You will need to pass "-F" as well. */
#ifndef DEBUG_NOFORK
#define DEBUG_NOFORK 0
#endif


/* For testing as non-root on shadowed systems, include the crypt of a password
 * here. You can then log in as any user with this password. Ensure that you
 * make your own password, and are careful about using this. This will also
 * disable some of the chown pty code etc*/
/* #define DEBUG_HACKCRYPT "hL8nrFDt0aJ3E" */ /* this is crypt("password") */

#endif