obfuz/Editor/Encryption/Instructions/BitRotateInstruction.cs

30 lines
987 B
C#

namespace Obfuz.Encryption.Instructions
{
public class BitRotateInstruction : EncryptionInstructionBase
{
private readonly int _rotateBitNum;
private readonly int _opKeyIndex;
public BitRotateInstruction(int rotateBitNum, int opKeyIndex)
{
_rotateBitNum = rotateBitNum;
_opKeyIndex = opKeyIndex;
}
public override int Encrypt(int value, int[] secretKey, int salt)
{
uint part1 = (uint)value << _rotateBitNum;
uint part2 = (uint)value >> (32 - _rotateBitNum);
return ((int)(part1 | part2) ^ secretKey[_opKeyIndex]) + salt;
}
public override int Decrypt(int value, int[] secretKey, int salt)
{
uint value2 = (uint)((value - salt) ^ secretKey[_opKeyIndex]);
uint part1 = value2 >> _rotateBitNum;
uint part2 = value2 << (32 - _rotateBitNum);
return (int)(part1 | part2);
}
}
}