view libtomcrypt/src/mac/pmac/pmac_shift_xor.c @ 1861:2b3a8026a6ce

Add re-exec for server This allows ASLR to re-randomize the address space for every connection, preventing some vulnerabilities from being exploitable by repeated probing. Overhead (memory and time) is yet to be confirmed. At present this is only enabled on Linux. Other BSD platforms with fexecve() would probably also work though have not been tested.
author Matt Johnston <matt@ucc.asn.au>
date Sun, 30 Jan 2022 10:14:56 +0800
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 pmac_shift_xor.c
   PMAC implementation, internal function, by Tom St Denis
*/

#ifdef LTC_PMAC

/**
  Internal function.  Performs the state update (adding correct multiple)
  @param pmac   The PMAC state.
*/
void pmac_shift_xor(pmac_state *pmac)
{
   int x, y;
   y = pmac_ntz(pmac->block_index++);
#ifdef LTC_FAST
   for (x = 0; x < pmac->block_len; x += sizeof(LTC_FAST_TYPE)) {
       *(LTC_FAST_TYPE_PTR_CAST((unsigned char *)pmac->Li + x)) ^=
       *(LTC_FAST_TYPE_PTR_CAST((unsigned char *)pmac->Ls[y] + x));
   }
#else
   for (x = 0; x < pmac->block_len; x++) {
       pmac->Li[x] ^= pmac->Ls[y][x];
   }
#endif
}

#endif

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