view libtomcrypt/src/mac/blake2/blake2smac_file.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 e9dba7abd939
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"

#ifdef LTC_BLAKE2SMAC

/**
  BLAKE2S MAC a file
  @param fname    The name of the file you wish to BLAKE2S MAC
  @param key      The secret key
  @param keylen   The length of the secret key
  @param mac      [out] The BLAKE2S MAC authentication tag
  @param maclen   [in/out]  The max size and resulting size of the authentication tag
  @return CRYPT_OK if successful, CRYPT_NOP if file support has been disabled
*/
int blake2smac_file(const char *fname, const unsigned char *key, unsigned long keylen, unsigned char *mac, unsigned long *maclen)
{
#ifdef LTC_NO_FILE
   LTC_UNUSED_PARAM(fname);
   LTC_UNUSED_PARAM(key);
   LTC_UNUSED_PARAM(keylen);
   LTC_UNUSED_PARAM(mac);
   LTC_UNUSED_PARAM(maclen);
   return CRYPT_NOP;
#else
   blake2smac_state st;
   FILE *in;
   unsigned char *buf;
   size_t x;
   int err;

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

   if ((buf = XMALLOC(LTC_FILE_READ_BUFSIZE)) == NULL) {
      return CRYPT_MEM;
   }

   if ((err = blake2smac_init(&st, *maclen, key, keylen)) != CRYPT_OK) {
      goto LBL_ERR;
   }

   in = fopen(fname, "rb");
   if (in == NULL) {
      err = CRYPT_FILE_NOTFOUND;
      goto LBL_ERR;
   }

   do {
      x = fread(buf, 1, LTC_FILE_READ_BUFSIZE, in);
      if ((err = blake2smac_process(&st, buf, (unsigned long)x)) != CRYPT_OK) {
         fclose(in);
         goto LBL_CLEANBUF;
      }
   } while (x == LTC_FILE_READ_BUFSIZE);

   if (fclose(in) != 0) {
      err = CRYPT_ERROR;
      goto LBL_CLEANBUF;
   }

   err = blake2smac_done(&st, mac, maclen);

LBL_CLEANBUF:
   zeromem(buf, LTC_FILE_READ_BUFSIZE);
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(&st, sizeof(blake2smac_state));
#endif
   XFREE(buf);
   return err;
#endif
}

#endif

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