Mercurial > dropbear

view libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence_ex.c @ 1857:6022df862942

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
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
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"


/**
  @file der_decode_sequence_ex.c
  ASN.1 DER, decode a SEQUENCE, Tom St Denis
*/

#ifdef LTC_DER

/**
   Decode a SEQUENCE
   @param in       The DER encoded input
   @param inlen    The size of the input
   @param list     The list of items to decode
   @param outlen   The number of items in the list
   @param ordered  Search an unordeded or ordered list
   @return CRYPT_OK on success
*/
int der_decode_sequence_ex(const unsigned char *in, unsigned long  inlen,
                           ltc_asn1_list *list,     unsigned long  outlen, int ordered)
{
   int           err, i;
   ltc_asn1_type type;
   unsigned long size, x, y, z, blksize;
   void          *data;

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

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

   /* sequence type? We allow 0x30 SEQUENCE and 0x31 SET since fundamentally they're the same structure */
   x = 0;
   if (in[x] != 0x30 && in[x] != 0x31) {
      return CRYPT_INVALID_PACKET;
   }
   ++x;

   /* check if the msb is set, which signals that the
    * 7 lsb bits represent the number of bytes of the length
    */
   if (in[x] < 128) {
      blksize = in[x++];
   } else {
      if (in[x] < 0x81 || in[x] > 0x83) {
         return CRYPT_INVALID_PACKET;
      }
      y = in[x++] & 0x7F;

      /* would reading the len bytes overrun? */
      if (x + y > inlen) {
         return CRYPT_INVALID_PACKET;
      }

      /* read len */
      blksize = 0;
      while (y--) {
          blksize = (blksize << 8) | (unsigned long)in[x++];
      }
   }

   /* would this blksize overflow? */
   if (x + blksize > inlen) {
      return CRYPT_INVALID_PACKET;
   }

   /* mark all as unused */
   for (i = 0; i < (int)outlen; i++) {
       list[i].used = 0;
   }

   /* ok read data */
   inlen = blksize;
   for (i = 0; i < (int)outlen; i++) {
       z    = 0;
       type = list[i].type;
       size = list[i].size;
       data = list[i].data;
       if (!ordered && list[i].used == 1) { continue; }

       if (type == LTC_ASN1_EOL) {
          break;
       }

       switch (type) {
           case LTC_ASN1_BOOLEAN:
               z = inlen;
               if ((err = der_decode_boolean(in + x, z, ((int *)data))) != CRYPT_OK) {
                   if (!ordered) { continue; }
                   goto LBL_ERR;
               }
               if ((err = der_length_boolean(&z)) != CRYPT_OK) {
                   goto LBL_ERR;
               }
               break;

           case LTC_ASN1_INTEGER:
               z = inlen;
               if ((err = der_decode_integer(in + x, z, data)) != CRYPT_OK) {
                  if (!ordered) {  continue; }
                  goto LBL_ERR;
               }
               if ((err = der_length_integer(data, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_SHORT_INTEGER:
               z = inlen;
               if ((err = der_decode_short_integer(in + x, z, data)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               if ((err = der_length_short_integer(((unsigned long*)data)[0], &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }

               break;

           case LTC_ASN1_BIT_STRING:
               z = inlen;
               if ((err = der_decode_bit_string(in + x, z, data, &size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_bit_string(size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_RAW_BIT_STRING:
               z = inlen;
               if ((err = der_decode_raw_bit_string(in + x, z, data, &size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_bit_string(size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_OCTET_STRING:
               z = inlen;
               if ((err = der_decode_octet_string(in + x, z, data, &size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_octet_string(size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_NULL:
               if (inlen < 2 || in[x] != 0x05 || in[x+1] != 0x00) {
                  if (!ordered) { continue; }
                  err = CRYPT_INVALID_PACKET;
                  goto LBL_ERR;
               }
               z = 2;
               break;

           case LTC_ASN1_OBJECT_IDENTIFIER:
               z = inlen;
               if ((err = der_decode_object_identifier(in + x, z, data, &size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_object_identifier(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_TELETEX_STRING:
               z = inlen;
               if ((err = der_decode_teletex_string(in + x, z, data, &size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_teletex_string(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_IA5_STRING:
               z = inlen;
               if ((err = der_decode_ia5_string(in + x, z, data, &size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_ia5_string(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;


           case LTC_ASN1_PRINTABLE_STRING:
               z = inlen;
               if ((err = der_decode_printable_string(in + x, z, data, &size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_printable_string(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_UTF8_STRING:
               z = inlen;
               if ((err = der_decode_utf8_string(in + x, z, data, &size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_utf8_string(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_UTCTIME:
               z = inlen;
               if ((err = der_decode_utctime(in + x, &z, data)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_GENERALIZEDTIME:
               z = inlen;
               if ((err = der_decode_generalizedtime(in + x, &z, data)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_SET:
               z = inlen;
               if ((err = der_decode_set(in + x, z, data, size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               if ((err = der_length_sequence(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_SETOF:
           case LTC_ASN1_SEQUENCE:
               /* detect if we have the right type */
               if ((type == LTC_ASN1_SETOF && (in[x] & 0x3F) != 0x31) || (type == LTC_ASN1_SEQUENCE && (in[x] & 0x3F) != 0x30)) {
                  err = CRYPT_INVALID_PACKET;
                  goto LBL_ERR;
               }

               z = inlen;
               if ((err = der_decode_sequence(in + x, z, data, size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               if ((err = der_length_sequence(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;


           case LTC_ASN1_CHOICE:
               z = inlen;
               if ((err = der_decode_choice(in + x, &z, data, size)) != CRYPT_OK) {
                  if (!ordered) { continue; }
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_CONSTRUCTED:
           case LTC_ASN1_CONTEXT_SPECIFIC:
           case LTC_ASN1_EOL:
               err = CRYPT_INVALID_ARG;
               goto LBL_ERR;
       }
       x           += z;
       inlen       -= z;
       list[i].used = 1;
       if (!ordered) {
          /* restart the decoder */
          i = -1;
       }
   }

   for (i = 0; i < (int)outlen; i++) {
      if (list[i].used == 0) {
          err = CRYPT_INVALID_PACKET;
          goto LBL_ERR;
      }
   }

   if (inlen == 0) {
      err = CRYPT_OK;
   } else {
      err = CRYPT_INPUT_TOO_LONG;
   }

LBL_ERR:
   return err;
}

#endif

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