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++;
  }
}

}  // namespace funcexp