view libtomcrypt/src/mac/pmac/pmac_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 pmac_memory_multi.c
   PMAC implementation, process multiple blocks of memory, by Tom St Denis
*/

#ifdef LTC_PMAC

/**
   PMAC multiple blocks of memory
   @param cipher   The index of the cipher desired
   @param key      The secret key
   @param keylen   The length of the secret key (octets)
   @param out      [out] Destination for the authentication tag
   @param outlen   [in/out] The max size and resulting size of the authentication tag
   @param in       The data you wish to send through PMAC
   @param inlen    The length of data you wish to send through PMAC (octets)
   @param ...      tuples of (data,len) pairs to PMAC, terminated with a (NULL,x) (x=don't care)
   @return CRYPT_OK if successful
*/
int pmac_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;
   pmac_state          *pmac;
   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 pmac state */
   pmac = XMALLOC(sizeof(pmac_state));
   if (pmac == NULL) {
      return CRYPT_MEM;
   }

   if ((err = pmac_init(pmac, cipher, key, keylen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
   va_start(args, inlen);
   curptr = in;
   curlen = inlen;
   for (;;) {
      /* process buf */
      if ((err = pmac_process(pmac, 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 = pmac_done(pmac, out, outlen)) != CRYPT_OK) {
      goto LBL_ERR;
   }
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(pmac, sizeof(pmac_state));
#endif
   XFREE(pmac);
   va_end(args);
   return err;
}

#endif

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