view libtomcrypt/src/mac/blake2/blake2smac_memory_multi.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
line wrap: on
line source

/* 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>

#ifdef LTC_BLAKE2SMAC

/**
   BLAKE2S MAC multiple blocks of memory to produce the authentication tag
   @param key       The secret key
   @param keylen    The length of the secret key (octets)
   @param mac       [out] Destination of the authentication tag
   @param maclen    [in/out] Max size and resulting size of authentication tag
   @param in        The data to BLAKE2S MAC
   @param inlen     The length of the data to BLAKE2S MAC (octets)
   @param ...       tuples of (data,len) pairs to BLAKE2S MAC, terminated with a (NULL,x) (x=don't care)
   @return CRYPT_OK if successful
*/
int blake2smac_memory_multi(const unsigned char *key, unsigned long keylen, unsigned char *mac, unsigned long *maclen, const unsigned char *in,  unsigned long inlen, ...)
{
   blake2smac_state st;
   int err;
   va_list args;
   const unsigned char *curptr;
   unsigned long curlen;

   LTC_ARGCHK(key    != NULL);
   LTC_ARGCHK(in     != NULL);
   LTC_ARGCHK(mac    != NULL);
   LTC_ARGCHK(maclen != NULL);

   va_start(args, inlen);
   curptr = in;
   curlen = inlen;
   if ((err = blake2smac_init(&st, *maclen, key, keylen)) != CRYPT_OK)          { goto LBL_ERR; }
   for (;;) {
      if ((err = blake2smac_process(&st, curptr, curlen)) != CRYPT_OK) { goto LBL_ERR; }
      curptr = va_arg(args, const unsigned char*);
      if (curptr == NULL) break;
      curlen = va_arg(args, unsigned long);
   }
   err = blake2smac_done(&st, mac, maclen);
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(&st, sizeof(blake2smac_state));
#endif
   va_end(args);
   return err;
}

#endif

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