コード例 #1
0
/**
  Store a mp_int integer
  @param num      The first mp_int to encode
  @param out      [out] The destination for the DER encoded integers
  @param outlen   [in/out] The max size and resulting size of the DER encoded integers
  @return CRYPT_OK if successful
*/
int der_encode_integer(void *num, unsigned char *out, unsigned long *outlen)
{  
   unsigned long tmplen, y;
   int           err, leading_zero;

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

   /* find out how big this will be */
   if ((err = der_length_integer(num, &tmplen)) != CRYPT_OK) {
      return err;
   }

   if (*outlen < tmplen) {
      *outlen = tmplen;
      return CRYPT_BUFFER_OVERFLOW;
   }

   if (mp_cmp_d(num, 0) != LTC_MP_LT) {
      /* we only need a leading zero if the msb of the first byte is one */
      if ((mp_count_bits(num) & 7) == 0 || mp_iszero(num) == LTC_MP_YES) {
         leading_zero = 1;
      } else {
         leading_zero = 0;
      }

      /* get length of num in bytes (plus 1 since we force the msbyte to zero) */
      y = mp_unsigned_bin_size(num) + leading_zero;
   } else {
      leading_zero = 0;
      y            = mp_count_bits(num);
      y            = y + (8 - (y & 7));
      y            = y >> 3;
      if (((mp_cnt_lsb(num)+1)==mp_count_bits(num)) && ((mp_count_bits(num)&7)==0)) --y;
   }

   /* now store initial data */
   *out++ = 0x02;
   if (y < 128) {
      /* short form */
      *out++ = (unsigned char)y;
   } else if (y < 256) {
      *out++ = 0x81;
      *out++ = (unsigned char)y;
   } else if (y < 65536UL) {
      *out++ = 0x82;
      *out++ = (unsigned char)((y>>8)&255);
      *out++ = (unsigned char)y;
   } else if (y < 16777216UL) {
コード例 #2
0
ファイル: der_decode_choice.c プロジェクト: DCIT/perl-CryptX
/**
   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_CUSTOM_TYPE:
               if (der_decode_custom_type(in, *inlen, &list[x]) == CRYPT_OK) {
                  if (der_length_custom_type(&list[x], &z, NULL) == CRYPT_OK) {
                     list[x].used = 1;
                     *inlen       = z;
                     return CRYPT_OK;
                  }
               }
               break;

           case LTC_ASN1_CHOICE:
           case LTC_ASN1_EOL:
               return CRYPT_INVALID_ARG;
       }
   }

   return CRYPT_INVALID_PACKET;
}
コード例 #3
0
/**
   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, type;
   unsigned long size, x, y, z, i, 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;

   if (in[x] < 128) {
      blksize = in[x++];
   } else if (in[x] & 0x80) {
      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 < outlen; i++) {
       list[i].used = 0;
   }

  /* ok read data */
   inlen = blksize;
   for (i = 0; i < 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) {
                   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_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_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_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;

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

LBL_ERR:
   return err;
}
コード例 #4
0
/**
   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
   @return CRYPT_OK on success
*/
int der_decode_sequence(const unsigned char *in,   unsigned long  inlen,
                              ltc_asn1_list *list, unsigned long  outlen)
{
   int           err, type;
   unsigned long size, x, y, z, i, blksize;
   void          *data;

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

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

   /* sequence type? */
   x = 0;
   if (in[x++] != 0x30) {
      return CRYPT_INVALID_PACKET;
   }

   if (in[x] < 128) {
      blksize = in[x++];
   } else if (in[x] & 0x80) {
      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;
  }

  /* ok read data */
   inlen = blksize;
   for (i = 0; i < outlen; i++) {
       type = list[i].type;
       size = list[i].size;
       data = list[i].data;

       if (type == LTC_ASN1_EOL) { 
          break;
       }

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


           case LTC_ASN1_SHORT_INTEGER:
               z = inlen;
               if ((err = der_decode_short_integer(in + x, z, data)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               if ((err = der_length_short_integer(size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               x     += z;
               inlen -= z;
               break;

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

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

           case LTC_ASN1_NULL:
               if (inlen < 2 || in[x] != 0x05 || in[x+1] != 0x00) {
                  err = CRYPT_INVALID_PACKET;
                  goto LBL_ERR;
               }
               x     += 2;
               inlen -= 2;
               break;
                  
           case LTC_ASN1_OBJECT_IDENTIFIER:
               z = inlen;
               if ((err = der_decode_object_identifier(in + x, z, data, &size)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               list[i].size = size;
               if ((err = der_length_object_identifier(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               x     += z;
               inlen -= z;
               break;

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


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

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

           case LTC_ASN1_SEQUENCE:
               z = inlen;
               if ((err = der_decode_sequence(in + x, z, data, size)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               if ((err = der_length_sequence(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               x     += z;
               inlen -= z;
               break;


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

           default:
               err = CRYPT_INVALID_ARG;
               goto LBL_ERR;
       }
   }
   err = CRYPT_OK;   

LBL_ERR:
   return err;
}  
コード例 #5
0
/**
   Extended-decode a Custom type

      This function is used to decode custom types and sequences/sets
      For custom types root is used
      For sequences/sets list and outlen are used

   @param in       The DER encoded input
   @param inlen    The size of the input
   @param root     The item that defines the custom type to decode
   @param list     The list of items to decode
   @param outlen   The number of items in the list
   @param flags    c.f. enum ltc_der_seq
   @return CRYPT_OK on success
*/
int der_decode_custom_type_ex(const unsigned char *in,   unsigned long  inlen,
                                    ltc_asn1_list *root,
                                    ltc_asn1_list *list, unsigned long  outlen,
                                    unsigned int   flags)
{
   int           err, seq_err, i, ordered;
   ltc_asn1_type type;
   ltc_asn1_list ident;
   unsigned long size, x, y, z, blksize;
   unsigned char* in_new = NULL;
   void          *data;

   LTC_ARGCHK(in   != NULL);

   /* get blk size */
   if (inlen < 2) {
      return CRYPT_INVALID_PACKET;
   }
   x = 0;

   if (root == NULL) {
      LTC_ARGCHK(list != NULL);

      /* sequence type? We allow 0x30 SEQUENCE and 0x31 SET since fundamentally they're the same structure */
      if (in[x] != 0x30 && in[x] != 0x31) {
         return CRYPT_INVALID_PACKET;
      }
      ++x;
   } else {
      if (root->type != LTC_ASN1_CUSTOM_TYPE) {
         return CRYPT_INVALID_PACKET;
      }

      /* Alloc a copy of the data for primitive handling. */
      if (root->pc == LTC_ASN1_PC_PRIMITIVE) {
         in_new = XMALLOC(inlen);
         if (in_new == NULL) {
            return CRYPT_MEM;
         }
         XMEMCPY(in_new, in, inlen);
         in = in_new;
      }

      y = inlen;
      if ((err = der_decode_asn1_identifier(in, &y, &ident)) != CRYPT_OK) {
         goto LBL_ERR;
      }
      if ((ident.type != root->type) ||
            (ident.klass != root->klass) ||
            (ident.pc != root->pc) ||
            (ident.tag != root->tag)) {
         err = CRYPT_INVALID_PACKET;
         goto LBL_ERR;
      }
      x += y;

      list = root->data;
      outlen = root->size;
   }

   if (root != NULL && root->pc == LTC_ASN1_PC_PRIMITIVE) {
      if (((unsigned long)root->used >= der_asn1_type_to_identifier_map_sz) ||
            (der_asn1_type_to_identifier_map[root->used] == -1)) {
         err = CRYPT_INVALID_PACKET;
         goto LBL_ERR;
      }

      root->type = (ltc_asn1_type)root->used;
      list = root;
      outlen = 1;

      x -= 1;
      in_new[x] = (unsigned char)der_asn1_type_to_identifier_map[list[0].type];
      blksize = inlen - x;
   } else {

      y = inlen - x;
      if ((err = der_decode_asn1_length(&in[x], &y, &blksize)) != CRYPT_OK) {
         goto LBL_ERR;
      }
      x += y;
   }

   /* would this blksize overflow? */
   if (blksize > (inlen - x)) {
      err = CRYPT_INVALID_PACKET;
      goto LBL_ERR;
   }

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

   /* ok read data */
   seq_err  = CRYPT_OK;
   blksize += x;
   inlen   -= x;
   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;
       }

       if (root != NULL && root->pc == LTC_ASN1_PC_PRIMITIVE && i != 0) {
          err = CRYPT_PK_ASN1_ERROR;
          goto LBL_ERR;
       }

       switch (type) {
           case LTC_ASN1_BOOLEAN:
               z = inlen;
               if ((err = der_decode_boolean(in + x, z, ((int *)data))) != CRYPT_OK) {
                  if (!ordered || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { 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 || list[i].optional) { continue; }
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_GENERALIZEDTIME:
               z = inlen;
               if ((err = der_decode_generalizedtime(in + x, &z, data)) != CRYPT_OK) {
                  if (!ordered || list[i].optional) { 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 || list[i].optional) { 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;
               err = der_decode_sequence_ex(in + x, z, data, size, flags);
               if (err == CRYPT_INPUT_TOO_LONG) {
                  seq_err = CRYPT_INPUT_TOO_LONG;
                  err = CRYPT_OK;
               }
               if (err != CRYPT_OK) {
                  if (!ordered || list[i].optional) { continue; }
                  goto LBL_ERR;
               }
               if ((err = der_length_sequence(data, size, &z)) != CRYPT_OK) {
                  goto LBL_ERR;
               }
               break;

           case LTC_ASN1_CUSTOM_TYPE:
               z = inlen;
               err = der_decode_custom_type(in + x, z, &list[i]);
               if (err == CRYPT_INPUT_TOO_LONG) {
                  seq_err = CRYPT_INPUT_TOO_LONG;
                  err = CRYPT_OK;
               }
               if (err != CRYPT_OK) {
                  if (!ordered || list[i].optional) { continue; }
                  goto LBL_ERR;
               }
               if ((err = der_length_custom_type(&list[i], &z, NULL)) != 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 || list[i].optional) { continue; }
                  goto LBL_ERR;
               }
               break;

           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 && list[i].optional == 0) {
          err = CRYPT_INVALID_PACKET;
          goto LBL_ERR;
      }
   }

   if (blksize == x && seq_err == CRYPT_OK && inlen == 0) {
      /* everything decoded and no errors in nested sequences */
      err = CRYPT_OK;
   } else if (blksize == x && seq_err == CRYPT_INPUT_TOO_LONG && inlen == 0) {
      /* a sequence reported too-long input, but now we've decoded everything */
      err = CRYPT_OK;
   } else if (blksize != x && ((flags & LTC_DER_SEQ_STRICT) == LTC_DER_SEQ_STRICT)) {
      err = CRYPT_INVALID_PACKET;
   } else {
      err = CRYPT_INPUT_TOO_LONG;
   }

LBL_ERR:
   if (in_new != NULL) {
      XFREE(in_new);
   }
   return err;
}
コード例 #6
0
ファイル: der_length_sequence.c プロジェクト: ipaddr/omim
/**
   Get the length of a DER sequence
   @param list   The sequences of items in the SEQUENCE
   @param inlen  The number of items
   @param outlen [out] The length required in octets to store it
   @return CRYPT_OK on success
*/
int der_length_sequence(ltc_asn1_list *list, unsigned long inlen,
                        unsigned long *outlen)
{
    int           err;
    ltc_asn1_type type;
    unsigned long size, x, y, i;
    void          *data;

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

    /* get size of output that will be required */
    y = 0;
    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:
            if ((err = der_length_boolean(&x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_INTEGER:
            if ((err = der_length_integer(data, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

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

        case LTC_ASN1_BIT_STRING:
        case LTC_ASN1_RAW_BIT_STRING:
            if ((err = der_length_bit_string(size, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_OCTET_STRING:
            if ((err = der_length_octet_string(size, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_NULL:
            y += 2;
            break;

        case LTC_ASN1_OBJECT_IDENTIFIER:
            if ((err = der_length_object_identifier(data, size, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_IA5_STRING:
            if ((err = der_length_ia5_string(data, size, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_TELETEX_STRING:
            if ((err = der_length_teletex_string(data, size, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_PRINTABLE_STRING:
            if ((err = der_length_printable_string(data, size, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_UTCTIME:
            if ((err = der_length_utctime(data, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_UTF8_STRING:
            if ((err = der_length_utf8_string(data, size, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;

        case LTC_ASN1_SET:
        case LTC_ASN1_SETOF:
        case LTC_ASN1_SEQUENCE:
            if ((err = der_length_sequence(data, size, &x)) != CRYPT_OK) {
                goto LBL_ERR;
            }
            y += x;
            break;


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

    /* calc header size */
    if (y < 128) {
        y += 2;
    } else if (y < 256) {
        /* 0x30 0x81 LL */
        y += 3;
    } else if (y < 65536UL) {
        /* 0x30 0x82 LL LL */
        y += 4;
    } else if (y < 16777216UL) {
        /* 0x30 0x83 LL LL LL */
        y += 5;
    } else {
        err = CRYPT_INVALID_ARG;
        goto LBL_ERR;
    }

    /* store size */
    *outlen = y;
    err     = CRYPT_OK;

LBL_ERR:
    return err;
}
コード例 #7
0
/** 
   ASN.1 DER Flexi(ble) decoder will decode arbitrary DER packets and create a linked list of the decoded elements.
   @param in      The input buffer
   @param inlen   [in/out] The length of the input buffer and on output the amount of decoded data 
   @param out     [out] A pointer to the linked list
   @return CRYPT_OK on success.
*/   
int der_decode_sequence_flexi(const unsigned char *in, unsigned long *inlen, ltc_asn1_list **out)
{
   ltc_asn1_list *l;
   unsigned long err, type, len, totlen, x, y;
   void          *realloc_tmp;
   int           isConstructed;
   
   LTC_ARGCHK(in    != NULL);
   LTC_ARGCHK(inlen != NULL);
   LTC_ARGCHK(out   != NULL);

   l = NULL;
   totlen = 0;
   
   /* scan the input and and get lengths and what not */
   while (*inlen) {     
      /* read the type byte */
      type = *in;

      /* fetch length */
      len = fetch_length(in, *inlen);
      if (len > *inlen) {
         err = CRYPT_INVALID_PACKET;
         goto error;
      }

      /* alloc new link */
      if (l == NULL) {
         l = XCALLOC(1, sizeof(*l));
         if (l == NULL) {
            err = CRYPT_MEM;
            goto error;
         }
      } else {
         l->next = XCALLOC(1, sizeof(*l));
         if (l->next == NULL) {
            err = CRYPT_MEM;
            goto error;
         }
         l->next->prev = l;
         l = l->next;
      }

      if ((isConstructed = ((type & 0xE0) == 0xA0 ? 1 : 0))) {
         /* constructed, use the 'used' field to store the original tag number */
         l->used = (type & 0x1F);
         /* treat constructed elements like SETs */
         type = 0x31;
      }
     
     /* now switch on type */
      switch (type) {
         case 0x01: /* BOOLEAN */
            l->type = LTC_ASN1_BOOLEAN;
            l->size = 1;
            l->data = XCALLOC(1, sizeof(int));
       
            if ((err = der_decode_boolean(in, *inlen, l->data)) != CRYPT_OK) {
               goto error;
            }
        
            if ((err = der_length_boolean(&len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x02: /* INTEGER */
             /* init field */
             l->type = LTC_ASN1_INTEGER;
             l->size = 1;
             if ((err = mp_init(&l->data)) != CRYPT_OK) {
                 goto error;
             }
             
             /* decode field */
             if ((err = der_decode_integer(in, *inlen, l->data)) != CRYPT_OK) {
                 goto error;
             }
             
             /* calc length of object */
             if ((err = der_length_integer(l->data, &len)) != CRYPT_OK) {
                 goto error;
             }
             break;

         case 0x03: /* BIT */
            /* init field */
            l->type = LTC_ASN1_BIT_STRING;
            l->size = len * 8; /* *8 because we store decoded bits one per char and they are encoded 8 per char.  */

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }
            
            if ((err = der_decode_bit_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }
            
            if ((err = der_length_bit_string(l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x04: /* OCTET */

            /* init field */
            l->type = LTC_ASN1_OCTET_STRING;
            l->size = len;

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }
            
            if ((err = der_decode_octet_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }
            
            if ((err = der_length_octet_string(l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x05: /* NULL */
         
            /* valid NULL is 0x05 0x00 */
            if (in[0] != 0x05 || in[1] != 0x00) {
               err = CRYPT_INVALID_PACKET;
               goto error;
            }
            
            /* simple to store ;-) */
            l->type = LTC_ASN1_NULL;
            l->data = NULL;
            l->size = 0;
            len     = 2;
            
            break;
         
         case 0x06: /* OID */
         
            /* init field */
            l->type = LTC_ASN1_OBJECT_IDENTIFIER;
            l->size = len;

            if ((l->data = XCALLOC(len, sizeof(unsigned long))) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }
            
            if ((err = der_decode_object_identifier(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }
            
            if ((err = der_length_object_identifier(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            
            /* resize it to save a bunch of mem */
            if ((realloc_tmp = XREALLOC(l->data, l->size * sizeof(unsigned long))) == NULL) {
               /* out of heap but this is not an error */
               break;
            }
            l->data = realloc_tmp;
            break;
  
         case 0x0C: /* UTF8 */
         
            /* init field */
            l->type = LTC_ASN1_UTF8_STRING;
            l->size = len;

            if ((l->data = XCALLOC(sizeof(wchar_t), l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }
            
            if ((err = der_decode_utf8_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }
            
            if ((err = der_length_utf8_string(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x13: /* PRINTABLE */
         
            /* init field */
            l->type = LTC_ASN1_PRINTABLE_STRING;
            l->size = len;

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }
            
            if ((err = der_decode_printable_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }
            
            if ((err = der_length_printable_string(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;
         
         case 0x14: /* TELETEXT */
         
            /* init field */
            l->type = LTC_ASN1_TELETEX_STRING;
            l->size = len;

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }
            
            if ((err = der_decode_teletex_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }
            
            if ((err = der_length_teletex_string(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;
            
         case 0x16: /* IA5 */
         
            /* init field */
            l->type = LTC_ASN1_IA5_STRING;
            l->size = len;

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }
            
            if ((err = der_decode_ia5_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }
            
            if ((err = der_length_ia5_string(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;
         
         case 0x17: /* UTC TIME */
         
            /* init field */
            l->type = LTC_ASN1_UTCTIME;
            l->size = 1;

            if ((l->data = XCALLOC(1, sizeof(ltc_utctime))) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }
            
            len = *inlen;
            if ((err = der_decode_utctime(in, &len, l->data)) != CRYPT_OK) {
               goto error;
            }
            
            if ((err = der_length_utctime(l->data, &len)) != CRYPT_OK) {
               goto error;
            }
            break;
         
         case 0x30: /* SEQUENCE */
         case 0x31: /* SET */
         
             /* init field */
             l->type = (isConstructed ? LTC_ASN1_CONSTRUCTED : ((type == 0x30) ? LTC_ASN1_SEQUENCE : LTC_ASN1_SET));
             
             /* we have to decode the SEQUENCE header and get it's length */
             
                /* move past type */
                ++in; --(*inlen);
                
                /* read length byte */
                x = *in++; --(*inlen);
                
                /* smallest SEQUENCE/SET header */
                y = 2;
                
                /* now if it's > 127 the next bytes are the length of the length */
                if (x > 128) {
                   x      &= 0x7F;
                   in     += x;
                   *inlen -= x;
                   
                   /* update sequence header len */
                   y      += x;
                }
             
             /* Sequence elements go as child */
             len = len - y;
             if ((err = der_decode_sequence_flexi(in, &len, &(l->child))) != CRYPT_OK) {
                goto error;
             }
             
             /* len update */
             totlen += y;
             
             /* link them up y0 */
             l->child->parent = l;
             
             break;
         default:
           /* invalid byte ... this is a soft error */
           /* remove link */
           if (l->prev) {
              l       = l->prev;
              XFREE(l->next);
              l->next = NULL;
           }
           goto outside;
      }
      
      /* advance pointers */
      totlen  += len;
      in      += len;
      *inlen  -= len;
   }
   
outside:   

   /* rewind l please */
   while (l->prev != NULL || l->parent != NULL) {
      if (l->parent != NULL) {
         l = l->parent;
      } else {
         l = l->prev;
      }
   }
   
   /* return */
   *out   = l;
   *inlen = totlen;
   return CRYPT_OK;

error:
   /* free list */
   der_sequence_free(l);

   return err;
}
コード例 #8
0
int der_tests(void)
{
   unsigned long x, y, z, zz, oid[2][32];
   unsigned char buf[3][2048];
   mp_int a, b, c, d, e, f, g;

   static const unsigned char rsa_oid_der[] = { 0x06, 0x06, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d };
   static const unsigned long rsa_oid[]     = { 1, 2, 840, 113549 };

   static const unsigned char rsa_ia5[]     = "*****@*****.**";
   static const unsigned char rsa_ia5_der[] = { 0x16, 0x0d, 0x74, 0x65, 0x73, 0x74, 0x31,
                                                0x40, 0x72, 0x73, 0x61, 0x2e, 0x63, 0x6f, 0x6d };

   static const unsigned char rsa_printable[] = "Test User 1";
   static const unsigned char rsa_printable_der[] = { 0x13, 0x0b, 0x54, 0x65, 0x73, 0x74, 0x20, 0x55, 
                                                      0x73, 0x65, 0x72, 0x20, 0x31 };

   static const ltc_utctime   rsa_time1 = { 91, 5, 6, 16, 45, 40, 1, 7, 0 };
   static const ltc_utctime   rsa_time2 = { 91, 5, 6, 23, 45, 40, 0, 0, 0 };
   ltc_utctime                tmp_time;

   static const unsigned char rsa_time1_der[] = { 0x17, 0x11, 0x39, 0x31, 0x30, 0x35, 0x30, 0x36, 0x31, 0x36, 0x34, 0x35, 0x34, 0x30, 0x2D, 0x30, 0x37, 0x30, 0x30 };
   static const unsigned char rsa_time2_der[] = { 0x17, 0x0d, 0x39, 0x31, 0x30, 0x35, 0x30, 0x36, 0x32, 0x33, 0x34, 0x35, 0x34, 0x30, 0x5a };

   DO(mpi_to_ltc_error(mp_init_multi(&a, &b, &c, &d, &e, &f, &g, NULL)));
   for (zz = 0; zz < 16; zz++) {
      for (z = 0; z < 1024; z++) {
         if (yarrow_read(buf[0], z, &yarrow_prng) != z) {
            fprintf(stderr, "Failed to read %lu bytes from yarrow\n", z);
            return 1;
         }
         DO(mpi_to_ltc_error(mp_read_unsigned_bin(&a, buf[0], z)));
         if (mp_iszero(&a) == MP_NO) { a.sign = buf[0][0] & 1 ? MP_ZPOS : MP_NEG; }
         x = sizeof(buf[0]);
         DO(der_encode_integer(&a, buf[0], &x));
         DO(der_length_integer(&a, &y));
         if (y != x) { fprintf(stderr, "DER INTEGER size mismatch\n"); return 1; }
         mp_zero(&b);
         DO(der_decode_integer(buf[0], y, &b));
         if (y != x || mp_cmp(&a, &b) != MP_EQ) {
            fprintf(stderr, "%lu: %lu vs %lu\n", z, x, y);
#ifdef BN_MP_TORADIX_C
            mp_todecimal(&a, buf[0]);
            mp_todecimal(&b, buf[1]);
            fprintf(stderr, "a == %s\nb == %s\n", buf[0], buf[1]);
#endif
            mp_clear_multi(&a, &b, &c, &d, &e, &f, &g, NULL);
            return 1;
         }
      }
   }

/* test short integer */
   for (zz = 0; zz < 256; zz++) {
      for (z = 1; z < 4; z++) {
         if (yarrow_read(buf[0], z, &yarrow_prng) != z) {
            fprintf(stderr, "Failed to read %lu bytes from yarrow\n", z);
            return 1;
         }
         /* encode with normal */
         DO(mpi_to_ltc_error(mp_read_unsigned_bin(&a, buf[0], z)));

         x = sizeof(buf[0]);
         DO(der_encode_integer(&a, buf[0], &x));

         /* encode with short */
         y = sizeof(buf[1]);
         DO(der_encode_short_integer(mp_get_int(&a), buf[1], &y));
         if (x != y || memcmp(buf[0], buf[1], x)) {
            fprintf(stderr, "DER INTEGER short encoding failed, %lu, %lu\n", x, y);
            for (z = 0; z < x; z++) fprintf(stderr, "%02x ", buf[0][z]); fprintf(stderr, "\n");
            for (z = 0; z < y; z++) fprintf(stderr, "%02x ", buf[1][z]); fprintf(stderr, "\n");
            mp_clear_multi(&a, &b, &c, &d, &e, &f, &g, NULL);
            return 1;
         }

         /* decode it */
         x = 0;
         DO(der_decode_short_integer(buf[1], y, &x));
         if (x != mp_get_int(&a)) {
            fprintf(stderr, "DER INTEGER short decoding failed, %lu, %lu\n", x, mp_get_int(&a));
            mp_clear_multi(&a, &b, &c, &d, &e, &f, &g, NULL);
            return 1;
         }
      }
   } 
   mp_clear_multi(&a, &b, &c, &d, &e, &f, &g, NULL);

   
/* Test bit string */
   for (zz = 1; zz < 1536; zz++) {
       yarrow_read(buf[0], zz, &yarrow_prng);
       for (z = 0; z < zz; z++) {
           buf[0][z] &= 0x01;
       }
       x = sizeof(buf[1]);
       DO(der_encode_bit_string(buf[0], zz, buf[1], &x));
       DO(der_length_bit_string(zz, &y));
       if (y != x) { 
          fprintf(stderr, "\nDER BIT STRING length of encoded not match expected : %lu, %lu, %lu\n", z, x, y);
          return 1;
       }

       y = sizeof(buf[2]);
       DO(der_decode_bit_string(buf[1], x, buf[2], &y));
       if (y != zz || memcmp(buf[0], buf[2], zz)) {
          fprintf(stderr, "%lu, %lu, %d\n", y, zz, memcmp(buf[0], buf[2], zz));
          return 1;
       }
   }

/* Test octet string */
   for (zz = 1; zz < 1536; zz++) {
       yarrow_read(buf[0], zz, &yarrow_prng);
       x = sizeof(buf[1]);
       DO(der_encode_octet_string(buf[0], zz, buf[1], &x));
       DO(der_length_octet_string(zz, &y));
       if (y != x) { 
          fprintf(stderr, "\nDER OCTET STRING length of encoded not match expected : %lu, %lu, %lu\n", z, x, y);
          return 1;
       }
       y = sizeof(buf[2]);
       DO(der_decode_octet_string(buf[1], x, buf[2], &y));
       if (y != zz || memcmp(buf[0], buf[2], zz)) {
          fprintf(stderr, "%lu, %lu, %d\n", y, zz, memcmp(buf[0], buf[2], zz));
          return 1;
       }
   }

/* test OID */
   x = sizeof(buf[0]);
   DO(der_encode_object_identifier(rsa_oid, sizeof(rsa_oid)/sizeof(rsa_oid[0]), buf[0], &x));
   if (x != sizeof(rsa_oid_der) || memcmp(rsa_oid_der, buf[0], x)) {
      fprintf(stderr, "rsa_oid_der encode failed to match, %lu, ", x);
      for (y = 0; y < x; y++) fprintf(stderr, "%02x ", buf[0][y]);
      fprintf(stderr, "\n");
      return 1;
   }

   y = sizeof(oid[0])/sizeof(oid[0][0]);
   DO(der_decode_object_identifier(buf[0], x, oid[0], &y));
   if (y != sizeof(rsa_oid)/sizeof(rsa_oid[0]) || memcmp(rsa_oid, oid[0], sizeof(rsa_oid))) {
      fprintf(stderr, "rsa_oid_der decode failed to match, %lu, ", y);
      for (z = 0; z < y; z++) fprintf(stderr, "%lu ", oid[0][z]);
      fprintf(stderr, "\n");
      return 1;
   }

   /* do random strings */
   for (zz = 0; zz < 5000; zz++) {
       /* pick a random number of words */
       yarrow_read(buf[0], 4, &yarrow_prng);
       LOAD32L(z, buf[0]);
       z = 2 + (z % ((sizeof(oid[0])/sizeof(oid[0][0])) - 2));
       
       /* fill them in */
       oid[0][0] = buf[0][0] % 3;
       oid[0][1] = buf[0][1] % 40;

       for (y = 2; y < z; y++) {
          yarrow_read(buf[0], 4, &yarrow_prng);
          LOAD32L(oid[0][y], buf[0]);
       }

       /* encode it */
       x = sizeof(buf[0]);
       DO(der_encode_object_identifier(oid[0], z, buf[0], &x));
       DO(der_length_object_identifier(oid[0], z, &y));
       if (x != y) {
          fprintf(stderr, "Random OID %lu test failed, length mismatch: %lu, %lu\n", z, x, y);
          for (x = 0; x < z; x++) fprintf(stderr, "%lu\n", oid[0][x]);
          return 1;
       }
       
       /* decode it */
       y = sizeof(oid[0])/sizeof(oid[0][0]);
       DO(der_decode_object_identifier(buf[0], x, oid[1], &y));
       if (y != z) {
          fprintf(stderr, "Random OID %lu test failed, decode length mismatch: %lu, %lu\n", z, x, y);
          return 1;
       }
       if (memcmp(oid[0], oid[1], sizeof(oid[0][0]) * z)) {
          fprintf(stderr, "Random OID %lu test failed, decoded values wrong\n", z);
          for (x = 0; x < z; x++) fprintf(stderr, "%lu\n", oid[0][x]); fprintf(stderr, "\n\n Got \n\n");
          for (x = 0; x < z; x++) fprintf(stderr, "%lu\n", oid[1][x]);
          return 1;
       }
   }

/* IA5 string */
   x = sizeof(buf[0]);
   DO(der_encode_ia5_string(rsa_ia5, strlen(rsa_ia5), buf[0], &x));
   if (x != sizeof(rsa_ia5_der) || memcmp(buf[0], rsa_ia5_der, x)) {
      fprintf(stderr, "IA5 encode failed: %lu, %lu\n", x, (unsigned long)sizeof(rsa_ia5_der));
      return 1;
   }
   DO(der_length_ia5_string(rsa_ia5, strlen(rsa_ia5), &y));
   if (y != x) {
      fprintf(stderr, "IA5 length failed to match: %lu, %lu\n", x, y);
      return 1;
   }
   y = sizeof(buf[1]);
   DO(der_decode_ia5_string(buf[0], x, buf[1], &y));
   if (y != strlen(rsa_ia5) || memcmp(buf[1], rsa_ia5, strlen(rsa_ia5))) {
       fprintf(stderr, "DER IA5 failed test vector\n");
       return 1;
   }

/* Printable string */
   x = sizeof(buf[0]);
   DO(der_encode_printable_string(rsa_printable, strlen(rsa_printable), buf[0], &x));
   if (x != sizeof(rsa_printable_der) || memcmp(buf[0], rsa_printable_der, x)) {
      fprintf(stderr, "PRINTABLE encode failed: %lu, %lu\n", x, (unsigned long)sizeof(rsa_printable_der));
      return 1;
   }
   DO(der_length_printable_string(rsa_printable, strlen(rsa_printable), &y));
   if (y != x) {
      fprintf(stderr, "printable length failed to match: %lu, %lu\n", x, y);
      return 1;
   }
   y = sizeof(buf[1]);
   DO(der_decode_printable_string(buf[0], x, buf[1], &y));
   if (y != strlen(rsa_printable) || memcmp(buf[1], rsa_printable, strlen(rsa_printable))) {
       fprintf(stderr, "DER printable failed test vector\n");
       return 1;
   }

/* Test UTC time */
   x = sizeof(buf[0]);
   DO(der_encode_utctime(&rsa_time1, buf[0], &x));
   if (x != sizeof(rsa_time1_der) || memcmp(buf[0], rsa_time1_der, x)) {
      fprintf(stderr, "UTCTIME encode of rsa_time1 failed: %lu, %lu\n", x, (unsigned long)sizeof(rsa_time1_der));
fprintf(stderr, "\n\n");
for (y = 0; y < x; y++) fprintf(stderr, "%02x ", buf[0][y]); printf("\n");

      return 1;
   }
   DO(der_length_utctime(&rsa_time1, &y));
   if (y != x) {
      fprintf(stderr, "UTCTIME length failed to match for rsa_time1: %lu, %lu\n", x, y);
      return 1;
   }
   DO(der_decode_utctime(buf[0], &y, &tmp_time));
   if (y != x || memcmp(&rsa_time1, &tmp_time, sizeof(ltc_utctime))) {
      fprintf(stderr, "UTCTIME decode failed for rsa_time1: %lu %lu\n", x, y);
fprintf(stderr, "\n\n%u %u %u %u %u %u %u %u %u\n\n", 
tmp_time.YY,
tmp_time.MM,
tmp_time.DD,
tmp_time.hh,
tmp_time.mm,
tmp_time.ss,
tmp_time.off_dir,
tmp_time.off_mm,
tmp_time.off_hh);
      return 1;
   }

   x = sizeof(buf[0]);
   DO(der_encode_utctime(&rsa_time2, buf[0], &x));
   if (x != sizeof(rsa_time2_der) || memcmp(buf[0], rsa_time2_der, x)) {
      fprintf(stderr, "UTCTIME encode of rsa_time2 failed: %lu, %lu\n", x, (unsigned long)sizeof(rsa_time1_der));
fprintf(stderr, "\n\n");
for (y = 0; y < x; y++) fprintf(stderr, "%02x ", buf[0][y]); printf("\n");

      return 1;
   }
   DO(der_length_utctime(&rsa_time2, &y));
   if (y != x) {
      fprintf(stderr, "UTCTIME length failed to match for rsa_time2: %lu, %lu\n", x, y);
      return 1;
   }
   DO(der_decode_utctime(buf[0], &y, &tmp_time));
   if (y != x || memcmp(&rsa_time2, &tmp_time, sizeof(ltc_utctime))) {
      fprintf(stderr, "UTCTIME decode failed for rsa_time2: %lu %lu\n", x, y);
fprintf(stderr, "\n\n%u %u %u %u %u %u %u %u %u\n\n", 
tmp_time.YY,
tmp_time.MM,
tmp_time.DD,
tmp_time.hh,
tmp_time.mm,
tmp_time.ss,
tmp_time.off_dir,
tmp_time.off_mm,
tmp_time.off_hh);


      return 1;
   }



   return der_choice_test();
}
コード例 #9
0
/**
   ASN.1 DER Flexi(ble) decoder will decode arbitrary DER packets and create a linked list of the decoded elements.
   @param in      The input buffer
   @param inlen   [in/out] The length of the input buffer and on output the amount of decoded data
   @param out     [out] A pointer to the linked list
   @return CRYPT_OK on success.
*/
int der_decode_sequence_flexi(const unsigned char *in, unsigned long *inlen, ltc_asn1_list **out)
{
   ltc_asn1_list *l;
   unsigned long err, type, len, totlen, data_offset;
   void          *realloc_tmp;

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

   l = NULL;
   totlen = 0;

   /* scan the input and and get lengths and what not */
   while (*inlen) {
      /* read the type byte */
      type = *in;

      /* fetch length */
      len = fetch_length(in, *inlen, &data_offset);
      if (len > *inlen) {
         err = CRYPT_INVALID_PACKET;
         goto error;
      }

      /* alloc new link */
      if (l == NULL) {
         l = XCALLOC(1, sizeof(*l));
         if (l == NULL) {
            err = CRYPT_MEM;
            goto error;
         }
      } else {
         l->next = XCALLOC(1, sizeof(*l));
         if (l->next == NULL) {
            err = CRYPT_MEM;
            goto error;
         }
         l->next->prev = l;
         l = l->next;
      }

      if ((type & 0x20) && (type != 0x30) && (type != 0x31)) {
         /* constructed, use the 'used' field to store the original identifier */
         l->used = type;
         /* treat constructed elements like SETs */
         type = 0x20;
      }
      else if ((type & 0xC0) == 0x80) {
         /* context-specific, use the 'used' field to store the original identifier */
         l->used = type;
         /* context-specific elements are treated as opaque data */
         type = 0x80;
      }

     /* now switch on type */
      switch (type) {
         case 0x01: /* BOOLEAN */
            l->type = LTC_ASN1_BOOLEAN;
            l->size = 1;
            l->data = XCALLOC(1, sizeof(int));

            if ((err = der_decode_boolean(in, *inlen, l->data)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_boolean(&len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x02: /* INTEGER */
             /* init field */
             l->type = LTC_ASN1_INTEGER;
             l->size = 1;
             if ((err = mp_init(&l->data)) != CRYPT_OK) {
                 goto error;
             }

             /* decode field */
             if ((err = der_decode_integer(in, *inlen, l->data)) != CRYPT_OK) {
                 goto error;
             }

             /* calc length of object */
             if ((err = der_length_integer(l->data, &len)) != CRYPT_OK) {
                 goto error;
             }
             break;

         case 0x03: /* BIT */
            /* init field */
            l->type = LTC_ASN1_BIT_STRING;
            l->size = len * 8; /* *8 because we store decoded bits one per char and they are encoded 8 per char.  */

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }

            if ((err = der_decode_bit_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_bit_string(l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x04: /* OCTET */

            /* init field */
            l->type = LTC_ASN1_OCTET_STRING;
            l->size = len;

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }

            if ((err = der_decode_octet_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_octet_string(l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x05: /* NULL */

            /* valid NULL is 0x05 0x00 */
            if (in[0] != 0x05 || in[1] != 0x00) {
               err = CRYPT_INVALID_PACKET;
               goto error;
            }

            /* simple to store ;-) */
            l->type = LTC_ASN1_NULL;
            l->data = NULL;
            l->size = 0;
            len     = 2;

            break;

         case 0x06: /* OID */

            /* init field */
            l->type = LTC_ASN1_OBJECT_IDENTIFIER;
            l->size = len;

            if ((l->data = XCALLOC(len, sizeof(unsigned long))) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }

            if ((err = der_decode_object_identifier(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_object_identifier(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }

            /* resize it to save a bunch of mem */
            if ((realloc_tmp = XREALLOC(l->data, l->size * sizeof(unsigned long))) == NULL) {
               /* out of heap but this is not an error */
               break;
            }
            l->data = realloc_tmp;
            break;

         case 0x0C: /* UTF8 */

            /* init field */
            l->type = LTC_ASN1_UTF8_STRING;
            l->size = len;

            if ((l->data = XCALLOC(sizeof(wchar_t), l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }

            if ((err = der_decode_utf8_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_utf8_string(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x13: /* PRINTABLE */

            /* init field */
            l->type = LTC_ASN1_PRINTABLE_STRING;
            l->size = len;

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }

            if ((err = der_decode_printable_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_printable_string(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x14: /* TELETEXT */

            /* init field */
            l->type = LTC_ASN1_TELETEX_STRING;
            l->size = len;

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }

            if ((err = der_decode_teletex_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_teletex_string(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x16: /* IA5 */

            /* init field */
            l->type = LTC_ASN1_IA5_STRING;
            l->size = len;

            if ((l->data = XCALLOC(1, l->size)) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }

            if ((err = der_decode_ia5_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_ia5_string(l->data, l->size, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x17: /* UTC TIME */

            /* init field */
            l->type = LTC_ASN1_UTCTIME;
            l->size = 1;

            if ((l->data = XCALLOC(1, sizeof(ltc_utctime))) == NULL) {
               err = CRYPT_MEM;
               goto error;
            }

            len = *inlen;
            if ((err = der_decode_utctime(in, &len, l->data)) != CRYPT_OK) {
               goto error;
            }

            if ((err = der_length_utctime(l->data, &len)) != CRYPT_OK) {
               goto error;
            }
            break;

         case 0x20: /* Any CONSTRUCTED element that is neither SEQUENCE nor SET */
         case 0x30: /* SEQUENCE */
         case 0x31: /* SET */

             /* init field */
             if (type == 0x20) {
                l->type = LTC_ASN1_CONSTRUCTED;
             }
             else if (type == 0x30) {
                l->type = LTC_ASN1_SEQUENCE;
             }
             else {
                l->type = LTC_ASN1_SET;
             }

             /* jump to the start of the data */
             in     += data_offset;
             *inlen -= data_offset;
             len = len - data_offset;

             /* Sequence elements go as child */
             if ((err = der_decode_sequence_flexi(in, &len, &(l->child))) != CRYPT_OK) {
                goto error;
             }

             /* len update */
             totlen += data_offset;

             /* the flexi decoder can also do nothing, so make sure a child has been allocated */
             if (l->child) {
                /* link them up y0 */
                l->child->parent = l;
             }

             break;

         case 0x80: /* Context-specific */
             l->type = LTC_ASN1_CONTEXT_SPECIFIC;

             if ((l->data = XCALLOC(1, len - data_offset)) == NULL) {
                err = CRYPT_MEM;
                goto error;
             }

             XMEMCPY(l->data, in + data_offset, len - data_offset);
             l->size = len - data_offset;

             break;

         default:
           /* invalid byte ... this is a soft error */
           /* remove link */
           if (l->prev) {
              l       = l->prev;
              XFREE(l->next);
              l->next = NULL;
           }
           goto outside;
      }

      /* advance pointers */
      totlen  += len;
      in      += len;
      *inlen  -= len;
   }

outside:

   /* in case we processed anything */
   if (totlen) {
      /* rewind l please */
      while (l->prev != NULL || l->parent != NULL) {
         if (l->parent != NULL) {
            l = l->parent;
         } else {
            l = l->prev;
         }
      }
   }

   /* return */
   *out   = l;
   *inlen = totlen;
   return CRYPT_OK;

error:
   /* free list */
   der_sequence_free(l);

   return err;
}
コード例 #10
0
ファイル: der_encode_integer.c プロジェクト: DCIT/perl-CryptX
/**
  Store a mp_int integer
  @param num      The first mp_int to encode
  @param out      [out] The destination for the DER encoded integers
  @param outlen   [in/out] The max size and resulting size of the DER encoded integers
  @return CRYPT_OK if successful
*/
int der_encode_integer(void *num, unsigned char *out, unsigned long *outlen)
{
   unsigned long tmplen, y, len;
   int           err, leading_zero;

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

   /* find out how big this will be */
   if ((err = der_length_integer(num, &tmplen)) != CRYPT_OK) {
      return err;
   }

   if (*outlen < tmplen) {
      *outlen = tmplen;
      return CRYPT_BUFFER_OVERFLOW;
   }

   if (mp_cmp_d(num, 0) != LTC_MP_LT) {
      /* we only need a leading zero if the msb of the first byte is one */
      if ((mp_count_bits(num) & 7) == 0 || mp_iszero(num) == LTC_MP_YES) {
         leading_zero = 1;
      } else {
         leading_zero = 0;
      }

      /* get length of num in bytes (plus 1 since we force the msbyte to zero) */
      y = mp_unsigned_bin_size(num) + leading_zero;
   } else {
      leading_zero = 0;
      y            = mp_count_bits(num);
      y            = y + (8 - (y & 7));
      y            = y >> 3;
      if (((mp_cnt_lsb(num)+1)==mp_count_bits(num)) && ((mp_count_bits(num)&7)==0)) --y;
   }

   /* now store initial data */
   *out++ = 0x02;
   len = *outlen - 1;
   if ((err = der_encode_asn1_length(y, out, &len)) != CRYPT_OK) {
      return err;
   }
   out += len;

   /* now store msbyte of zero if num is non-zero */
   if (leading_zero) {
      *out++ = 0x00;
   }

   /* if it's not zero store it as big endian */
   if (mp_cmp_d(num, 0) == LTC_MP_GT) {
      /* now store the mpint */
      if ((err = mp_to_unsigned_bin(num, out)) != CRYPT_OK) {
          return err;
      }
   } else if (mp_iszero(num) != LTC_MP_YES) {
      void *tmp;

      /* negative */
      if (mp_init(&tmp) != CRYPT_OK) {
         return CRYPT_MEM;
      }

      /* 2^roundup and subtract */
      y = mp_count_bits(num);
      y = y + (8 - (y & 7));
      if (((mp_cnt_lsb(num)+1)==mp_count_bits(num)) && ((mp_count_bits(num)&7)==0)) y -= 8;
      if (mp_2expt(tmp, y) != CRYPT_OK || mp_add(tmp, num, tmp) != CRYPT_OK) {
         mp_clear(tmp);
         return CRYPT_MEM;
      }
      if ((err = mp_to_unsigned_bin(tmp, out)) != CRYPT_OK) {
         mp_clear(tmp);
         return err;
      }
      mp_clear(tmp);
   }

   /* we good */
   *outlen = tmplen;
   return CRYPT_OK;
}