private int Gost28147_mainStep(int n1, int key)
{
int cm = (key + n1); // CM1
// S-box replacing
int om = S[ 0 + ((cm >> (0 * 4)) & 0xF)] << (0 * 4);
om += S[ 16 + ((cm >> (1 * 4)) & 0xF)] << (1 * 4);
om += S[ 32 + ((cm >> (2 * 4)) & 0xF)] << (2 * 4);
om += S[ 48 + ((cm >> (3 * 4)) & 0xF)] << (3 * 4);
om += S[ 64 + ((cm >> (4 * 4)) & 0xF)] << (4 * 4);
om += S[ 80 + ((cm >> (5 * 4)) & 0xF)] << (5 * 4);
om += S[ 96 + ((cm >> (6 * 4)) & 0xF)] << (6 * 4);
om += S[112 + ((cm >> (7 * 4)) & 0xF)] << (7 * 4);
// return om << 11 | om >>> (32-11); // 11-leftshift
int omLeft = om << 11;
int omRight = (int)(((uint) om) >> (32 - 11)); // Note: Casts required to get unsigned bit rotation
return omLeft | omRight;
}