view libtomcrypt/src/pk/asn1/der/sequence/der_encode_sequence_ex.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
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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 der_encode_sequence_ex.c
  ASN.1 DER, encode a SEQUENCE, Tom St Denis
*/

#ifdef LTC_DER

/**
   Encode a SEQUENCE
   @param list      The list of items to encode
   @param inlen     The number of items in the list
   @param out       [out] The destination
   @param outlen    [in/out] The size of the output
   @param type_of   LTC_ASN1_SEQUENCE or LTC_ASN1_SET/LTC_ASN1_SETOF
   @return CRYPT_OK on success
*/
int der_encode_sequence_ex(ltc_asn1_list *list, unsigned long inlen,
                           unsigned char *out,  unsigned long *outlen, int type_of)
{
   int           err;
   ltc_asn1_type type;
   unsigned long size, x, y, z, i;
   void          *data;

   LTC_ARGCHK(list    != NULL);
   LTC_ARGCHK(out     != NULL);
   LTC_ARGCHK(outlen  != NULL);

   /* get size of output that will be required */
   y = 0; z = 0;
   if ((err = der_length_sequence_ex(list, inlen, &y, &z)) != CRYPT_OK) return CRYPT_INVALID_ARG;

   /* too big ? */
   if (*outlen < y) {
      *outlen = y;
      err = CRYPT_BUFFER_OVERFLOW;
      goto LBL_ERR;
   }

   /* store header */
   x = 0;
   out[x++] = (type_of == LTC_ASN1_SEQUENCE) ? 0x30 : 0x31;

   if (z < 128) {
      out[x++] = (unsigned char)z;
   } else if (z < 256) {
      out[x++] = 0x81;
      out[x++] = (unsigned char)z;
   } else if (z < 65536UL) {
      out[x++] = 0x82;
      out[x++] = (unsigned char)((z>>8UL)&255);
      out[x++] = (unsigned char)(z&255);
   } else if (z < 16777216UL) {
      out[x++] = 0x83;
      out[x++] = (unsigned char)((z>>16UL)&255);
      out[x++] = (unsigned char)((z>>8UL)&255);
      out[x++] = (unsigned char)(z&255);
   }

   /* store data */
   *outlen -= x;
   for (i = 0; i < inlen; i++) {
       type = list[i].type;
       size = list[i].size;
       data = list[i].data;

       if (type == LTC_ASN1_EOL) {
          break;
       }

       switch (type) {
            case LTC_ASN1_BOOLEAN:
               z = *outlen;
               if ((err = der_encode_boolean(*((int *)data), out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_INTEGER:
               z = *outlen;
               if ((err = der_encode_integer(data, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_SHORT_INTEGER:
               z = *outlen;
               if ((err = der_encode_short_integer(*((unsigned long*)data), out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_BIT_STRING:
               z = *outlen;
               if ((err = der_encode_bit_string(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_RAW_BIT_STRING:
               z = *outlen;
               if ((err = der_encode_raw_bit_string(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_OCTET_STRING:
               z = *outlen;
               if ((err = der_encode_octet_string(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_NULL:
               out[x] = 0x05;
               out[x+1] = 0x00;
               z = 2;
               break;

           case LTC_ASN1_OBJECT_IDENTIFIER:
               z = *outlen;
               if ((err = der_encode_object_identifier(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_IA5_STRING:
               z = *outlen;
               if ((err = der_encode_ia5_string(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_PRINTABLE_STRING:
               z = *outlen;
               if ((err = der_encode_printable_string(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_UTF8_STRING:
               z = *outlen;
               if ((err = der_encode_utf8_string(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_UTCTIME:
               z = *outlen;
               if ((err = der_encode_utctime(data, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_GENERALIZEDTIME:
               z = *outlen;
               if ((err = der_encode_generalizedtime(data, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_SET:
               z = *outlen;
               if ((err = der_encode_set(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_SETOF:
               z = *outlen;
               if ((err = der_encode_setof(data, size, out + x, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_SEQUENCE:
               z = *outlen;
               if ((err = der_encode_sequence_ex(data, size, out + x, &z, type)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_CHOICE:
           case LTC_ASN1_CONSTRUCTED:
           case LTC_ASN1_CONTEXT_SPECIFIC:
           case LTC_ASN1_EOL:
           case LTC_ASN1_TELETEX_STRING:
               err = CRYPT_INVALID_ARG;
               goto LBL_ERR;
       }

       x       += z;
       *outlen -= z;
   }
   *outlen = x;
   err = CRYPT_OK;

LBL_ERR:
   return err;
}

#endif

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