view scpmisc.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 292f79307600
children
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/*	$OpenBSD: misc.h,v 1.12 2002/03/19 10:49:35 markus Exp $	*/

/*
 * Author: Tatu Ylonen <[email protected]>
 * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
 *                    All rights reserved
 *
 * 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".
 */

char	*chop(char *);
char	*strdelim(char **);
void	 set_nonblock(int);
void	 unset_nonblock(int);
void	 set_nodelay(int);
int	 a2port(const char *);
char	*cleanhostname(char *);
char	*colon(char *);
long	 convtime(const char *);

struct passwd *pwcopy(struct passwd *);

typedef struct arglist arglist;
struct arglist {
	char    **list;
	u_int   num;
	u_int   nalloc;
};
void	 addargs(arglist *, char *, ...);
void	 replacearg(arglist *, u_int, char *, ...);
void	 freeargs(arglist *);

/* from xmalloc.h */
void	*xmalloc(size_t);
void	*xrealloc(void *, size_t);
void     xfree(void *);
char	*xstrdup(const char *);

char *ssh_get_progname(char *);
void fatal(char* fmt,...);
void sanitise_stdfd(void);

/* Required for non-BSD platforms, from OpenSSH's defines.h */
#ifndef timersub
#define timersub(a, b, result)                  \
   do {                             \
      (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;     \
      (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;      \
      if ((result)->tv_usec < 0) {              \
     --(result)->tv_sec;                    \
     (result)->tv_usec += 1000000;              \
      }                             \
   } while (0)
#endif

#ifndef TIMEVAL_TO_TIMESPEC
#define TIMEVAL_TO_TIMESPEC(tv, ts) {                   \
    (ts)->tv_sec = (tv)->tv_sec;                    \
    (ts)->tv_nsec = (tv)->tv_usec * 1000;               \
}
#endif