mariadb-columnstore-engine/utils/funcexp/sql_crypt.cpp

#include <cstdlib>
#include <string>
using namespace std;

#include "sql_crypt.h"

namespace funcexp
{

void SQL_CRYPT::init(ulong *rand_nr)
{
  uint i;
  my_rnd_init(&rand,rand_nr[0],rand_nr[1]);

  for (i=0 ; i<=255; i++)
   decode_buff[i]= (char) i;

  for (i=0 ; i<= 255 ; i++)
  {
    int idx= (uint) (my_rnd(&rand)*255.0);
    char a= decode_buff[idx];
    decode_buff[idx]= decode_buff[i];
    decode_buff[+i]=a;
  }
  for (i=0 ; i <= 255 ; i++)
   encode_buff[(unsigned char) decode_buff[i]]=i;
  org_rand=rand;
  shift=0;
}


void SQL_CRYPT::encode(char *str,uint length)
{
  for (uint i=0; i < length; i++)
  {
    shift^=(uint) (my_rnd(&rand)*255.0);
    uint idx= (uint) (unsigned char) str[0];
    *str++ = (char) ((unsigned char) encode_buff[idx] ^ shift);
    shift^= idx;
  }
}


void SQL_CRYPT::decode(char *str,uint length)
{
  for (uint i=0; i < length; i++)
  {
    shift^=(uint) (my_rnd(&rand)*255.0);
    uint idx= (uint) ((unsigned char) str[0] ^ shift);
    *str = decode_buff[idx];
    shift^= (uint) (unsigned char) *str++;
  }
}

}