view libtomcrypt/src/pk/asn1/der/choice/der_decode_choice.c @ 1857:6022df862942

Use DSCP for IP QoS traffic classes The previous TOS values are deprecated and not used by modern traffic classifiers. This sets AF21 for "interactive" traffic (with a tty). Non-tty traffic sets AF11 - that indicates high throughput but is not lowest priority (which would be CS1 or LE). This differs from the CS1 used by OpenSSH, it lets interactive git over SSH have higher priority than background least effort traffic. Dropbear's settings here should be suitable with the diffservs used by CAKE qdisc.
author Matt Johnston <matt@ucc.asn.au>
date Tue, 25 Jan 2022 17:32:20 +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_decode_choice.c
  ASN.1 DER, decode a CHOICE, Tom St Denis
*/

#ifdef LTC_DER

/**
   Decode a CHOICE
   @param in       The DER encoded input
   @param inlen    [in/out] The size of the input and resulting size of read type
   @param list     The list of items to decode
   @param outlen   The number of items in the list
   @return CRYPT_OK on success
*/
int der_decode_choice(const unsigned char *in,   unsigned long *inlen,
                            ltc_asn1_list *list, unsigned long  outlen)
{
   unsigned long size, x, z;
   void          *data;

   LTC_ARGCHK(in    != NULL);
   LTC_ARGCHK(inlen != NULL);
   LTC_ARGCHK(list  != NULL);

   /* get blk size */
   if (*inlen < 2) {
      return CRYPT_INVALID_PACKET;
   }

   /* set all of the "used" flags to zero */
   for (x = 0; x < outlen; x++) {
       list[x].used = 0;
   }

   /* now scan until we have a winner */
   for (x = 0; x < outlen; x++) {
       size = list[x].size;
       data = list[x].data;

       switch (list[x].type) {
           case LTC_ASN1_BOOLEAN:
               if (der_decode_boolean(in, *inlen, data) == CRYPT_OK) {
                  if (der_length_boolean(&z) == CRYPT_OK) {
                      list[x].used = 1;
                      *inlen       = z;
                      return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_INTEGER:
               if (der_decode_integer(in, *inlen, data) == CRYPT_OK) {
                  if (der_length_integer(data, &z) == CRYPT_OK) {
                      list[x].used = 1;
                      *inlen       = z;
                      return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_SHORT_INTEGER:
               if (der_decode_short_integer(in, *inlen, data) == CRYPT_OK) {
                  if (der_length_short_integer(size, &z) == CRYPT_OK) {
                      list[x].used = 1;
                      *inlen       = z;
                      return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_BIT_STRING:
               if (der_decode_bit_string(in, *inlen, data, &size) == CRYPT_OK) {
                  if (der_length_bit_string(size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     list[x].size = size;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_RAW_BIT_STRING:
               if (der_decode_raw_bit_string(in, *inlen, data, &size) == CRYPT_OK) {
                  if (der_length_bit_string(size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     list[x].size = size;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_OCTET_STRING:
               if (der_decode_octet_string(in, *inlen, data, &size) == CRYPT_OK) {
                  if (der_length_octet_string(size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     list[x].size = size;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_NULL:
               if (*inlen == 2 && in[x] == 0x05 && in[x+1] == 0x00) {
                  *inlen = 2;
                  list[x].used   = 1;
                  return CRYPT_OK;
               }
               break;

           case LTC_ASN1_OBJECT_IDENTIFIER:
               if (der_decode_object_identifier(in, *inlen, data, &size) == CRYPT_OK) {
                  if (der_length_object_identifier(data, size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     list[x].size = size;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_TELETEX_STRING:
               if (der_decode_teletex_string(in, *inlen, data, &size) == CRYPT_OK) {
                  if (der_length_teletex_string(data, size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     list[x].size = size;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_IA5_STRING:
               if (der_decode_ia5_string(in, *inlen, data, &size) == CRYPT_OK) {
                  if (der_length_ia5_string(data, size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     list[x].size = size;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_PRINTABLE_STRING:
               if (der_decode_printable_string(in, *inlen, data, &size) == CRYPT_OK) {
                  if (der_length_printable_string(data, size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     list[x].size = size;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_UTF8_STRING:
               if (der_decode_utf8_string(in, *inlen, data, &size) == CRYPT_OK) {
                  if (der_length_utf8_string(data, size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     list[x].size = size;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_UTCTIME:
               z = *inlen;
               if (der_decode_utctime(in, &z, data) == CRYPT_OK) {
                  list[x].used = 1;
                  *inlen       = z;
                  return CRYPT_OK;
               }
               break;

           case LTC_ASN1_GENERALIZEDTIME:
               z = *inlen;
               if (der_decode_generalizedtime(in, &z, data) == CRYPT_OK) {
                  list[x].used = 1;
                  *inlen       = z;
                  return CRYPT_OK;
               }
               break;

           case LTC_ASN1_SET:
           case LTC_ASN1_SETOF:
           case LTC_ASN1_SEQUENCE:
               if (der_decode_sequence(in, *inlen, data, size) == CRYPT_OK) {
                  if (der_length_sequence(data, size, &z) == CRYPT_OK) {
                     list[x].used = 1;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_CHOICE:
           case LTC_ASN1_CONSTRUCTED:
           case LTC_ASN1_CONTEXT_SPECIFIC:
           case LTC_ASN1_EOL:
               return CRYPT_INVALID_ARG;
       }
   }

   return CRYPT_INVALID_PACKET;
}

#endif

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