view libtomcrypt/src/misc/compare_testvector.c @ 1715:3974f087d9c0

Disallow leading lines before the ident for server (#102) Per RFC4253 4.2 clients must be able to process other lines of data before the version string, server behavior is not defined neither with MUST/SHOULD nor with MAY. If server process up to 50 lines too - it may cause too long hanging session with invalid/evil client that consume host resources and potentially may lead to DDoS on poor embedded boxes. Let's require first line from client to be version string and fail early if it's not - matches both RFC and real OpenSSH behavior.
author Vladislav Grishenko <themiron@users.noreply.github.com>
date Mon, 15 Jun 2020 18:22:18 +0500
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"

/**
  @file compare_testvector.c
  Function to compare two testvectors and print a (detailed) error-message if required, Steffen Jaeckel
*/

#if defined(LTC_TEST) && defined(LTC_TEST_DBG)
static void _print_hex(const char* what, const void* v, const unsigned long l)
{
  const unsigned char* p = v;
  unsigned long x, y = 0, z;
  fprintf(stderr, "%s contents: \n", what);
  for (x = 0; x < l; ) {
      fprintf(stderr, "%02X ", p[x]);
      if (!(++x % 16) || x == l) {
         if((x % 16) != 0) {
            z = 16 - (x % 16);
            if(z >= 8)
               fprintf(stderr, " ");
            for (; z != 0; --z) {
               fprintf(stderr, "   ");
            }
         }
         fprintf(stderr, " | ");
         for(; y < x; y++) {
            if((y % 8) == 0)
               fprintf(stderr, " ");
            if(isgraph(p[y]))
               fprintf(stderr, "%c", p[y]);
            else
               fprintf(stderr, ".");
         }
         fprintf(stderr, "\n");
      }
      else if((x % 8) == 0) {
         fprintf(stderr, " ");
      }
  }
}
#endif

/**
  Compare two test-vectors

  @param is             The data as it is
  @param is_len         The length of is
  @param should         The data as it should
  @param should_len     The length of should
  @param what           The type of the data
  @param which          The iteration count
  @return 0 on equality, -1 or 1 on difference
*/
int compare_testvector(const void* is, const unsigned long is_len, const void* should, const unsigned long should_len, const char* what, int which)
{
   int res = 0;
   if(is_len != should_len)
      res = is_len > should_len ? -1 : 1;
   else
      res = XMEMCMP(is, should, is_len);

#if defined(LTC_TEST) && defined(LTC_TEST_DBG)
   if (res != 0) {
      fprintf(stderr, "Testvector #%i of %s failed:\n", which, what);
      _print_hex("SHOULD", should, should_len);
      _print_hex("IS    ", is, is_len);
   }
#else
   LTC_UNUSED_PARAM(which);
   LTC_UNUSED_PARAM(what);
#endif

   return res;
}

/* ref:         $Format:%D$ */
/* git commit:  $Format:%H$ */
/* commit time: $Format:%ai$ */