...int asn1parse( const unsigned char *buffer,                int length,                struct asn1struct *top_level_token ){    unsigned int tag;  unsigned char tag_length_byte;  unsigned long tag_length;  const unsigned char *ptr;  const unsigned char *ptr_begin;  struct asn1struct *token;
  ptr = buffer;  token = top_level_token;
  while ( length )  {   ptr_begin = ptr;   tag = *ptr;   ptr++;   length--;
    if ( ( tag & 0x1F ) == 0x1F )   {     tag = 0;     while ( *ptr & 0x80 )     {       tag <<= 8;       tag |= *ptr & 0x7F;     }    }
    tag_length_byte = *ptr;    ptr++;    length--;
       if ( tag_length_byte & 0x80 )    {      const unsigned char *len_ptr = ptr;      tag_length = 0;      while ( ( len_ptr - ptr ) < ( tag_length_byte & 0x7F ) )      {        tag_length <<= 8;        tag_length |= *(len_ptr++);        length--;      }      ptr = len_ptr;    }    else    {      tag_length = tag_length_byte;    }       token->constructed = tag & 0x20;    token->tag_class = ( tag & 0xC0 ) >> 6;    token->tag = tag & 0x1F;    token->length = tag_length;    token->data = ptr;    token->children = NULL;    token->next = NULL;
    if ( tag & 0x20 )    {      token->length = tag_length + ( ptr - ptr_begin );
      token->data = ptr_begin;
       token->children = ( struct asn1struct * )         malloc( sizeof( struct asn1struct ) );      asn1parse( ptr, tag_length, token->children );    }
    ptr += tag_length;    length -= tag_length;
     if ( length )    {      token->next = ( struct asn1struct * ) malloc( sizeof( struct asn1struct ) );       token = token->next;    }  }    return 0;}...