view libtomcrypt/src/pk/asn1/der/printable_string/der_encode_printable_string.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 der_encode_printable_string.c
  ASN.1 DER, encode a printable STRING, Tom St Denis
*/

#ifdef LTC_DER

/**
  Store an printable STRING
  @param in       The array of printable to store (one per char)
  @param inlen    The number of printable to store
  @param out      [out] The destination for the DER encoded printable STRING
  @param outlen   [in/out] The max size and resulting size of the DER printable STRING
  @return CRYPT_OK if successful
*/
int der_encode_printable_string(const unsigned char *in, unsigned long inlen,
                                unsigned char *out, unsigned long *outlen)
{
   unsigned long x, y, len;
   int           err;

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

   /* get the size */
   if ((err = der_length_printable_string(in, inlen, &len)) != CRYPT_OK) {
      return err;
   }

   /* too big? */
   if (len > *outlen) {
      *outlen = len;
      return CRYPT_BUFFER_OVERFLOW;
   }

   /* encode the header+len */
   x = 0;
   out[x++] = 0x13;
   if (inlen < 128) {
      out[x++] = (unsigned char)inlen;
   } else if (inlen < 256) {
      out[x++] = 0x81;
      out[x++] = (unsigned char)inlen;
   } else if (inlen < 65536UL) {
      out[x++] = 0x82;
      out[x++] = (unsigned char)((inlen>>8)&255);
      out[x++] = (unsigned char)(inlen&255);
   } else if (inlen < 16777216UL) {
      out[x++] = 0x83;
      out[x++] = (unsigned char)((inlen>>16)&255);
      out[x++] = (unsigned char)((inlen>>8)&255);
      out[x++] = (unsigned char)(inlen&255);
   } else {
      return CRYPT_INVALID_ARG;
   }

   /* store octets */
   for (y = 0; y < inlen; y++) {
       out[x++] = der_printable_char_encode(in[y]);
   }

   /* retun length */
   *outlen = x;

   return CRYPT_OK;
}

#endif

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