view libtomcrypt/src/mac/f9/f9_memory_multi.c @ 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 6dba84798cd5
children
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 */
#include "tomcrypt.h"
#include <stdarg.h>

/**
  @file f9_memory_multi.c
  f9 support, process multiple blocks of memory, Tom St Denis
*/

#ifdef LTC_F9_MODE

/**
   f9 multiple blocks of memory
   @param cipher    The index of the desired cipher
   @param key       The secret key
   @param keylen    The length of the secret key (octets)
   @param out       [out] The destination of the authentication tag
   @param outlen    [in/out]  The max size and resulting size of the authentication tag (octets)
   @param in        The data to send through f9
   @param inlen     The length of the data to send through f9 (octets)
   @param ...       tuples of (data,len) pairs to f9, terminated with a (NULL,x) (x=don't care)
   @return CRYPT_OK if successful
*/
int f9_memory_multi(int cipher,
                const unsigned char *key, unsigned long keylen,
                      unsigned char *out, unsigned long *outlen,
                const unsigned char *in,  unsigned long inlen, ...)
{
   int                  err;
   f9_state          *f9;
   va_list              args;
   const unsigned char *curptr;
   unsigned long        curlen;

   LTC_ARGCHK(key    != NULL);
   LTC_ARGCHK(in     != NULL);
   LTC_ARGCHK(out    != NULL);
   LTC_ARGCHK(outlen != NULL);

   /* allocate ram for f9 state */
   f9 = XMALLOC(sizeof(f9_state));
   if (f9 == NULL) {
      return CRYPT_MEM;
   }

   /* f9 process the message */
   if ((err = f9_init(f9, cipher, key, keylen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   va_start(args, inlen);
   curptr = in;
   curlen = inlen;
   for (;;) {
      /* process buf */
      if ((err = f9_process(f9, curptr, curlen)) != CRYPT_OK) {
         goto LBL_ERR;
      }
      /* step to next */
      curptr = va_arg(args, const unsigned char*);
      if (curptr == NULL) {
         break;
      }
      curlen = va_arg(args, unsigned long);
   }
   if ((err = f9_done(f9, out, outlen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(f9, sizeof(f9_state));
#endif
   XFREE(f9);
   va_end(args);
   return err;
}

#endif

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