void CSSdescramble(unsigned char *sec,unsigned char *key)
{
        unsigned int t1,t2,t3,t4,t5,t6;
        unsigned char *end=sec+0x800;

        t1=key[0]^sec[0x54]|0x100;
        t2=key[1]^sec[0x55];
        t3=(*((unsigned int *)(key+2)))^(*((unsigned int *)(sec+0x56)));
        t4=t3&7;
        t3=t3*2+8-t4;
        sec+=0x80;
        t5=0;
        while(sec!=end)
        {
                t4=CSStab2[t2]^CSStab3[t1];
                t2=t1>>1;
                t1=((t1&1)<<8)^t4;
                t4=CSStab5[t4];
                t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
                t3=(t3<<8)|t6;
                t6=CSStab4[t6];
                t5+=t6+t4;
                *sec++=CSStab1[*sec]^(t5&0xff);
                t5>>=8;
        }
}

void CSStitlekey1(unsigned char *key,unsigned char *im)
{
        unsigned int t1,t2,t3,t4,t5,t6;
        unsigned char k[5];
        int i;

        t1=im[0]|0x100;
        t2=im[1];
        t3=*((unsigned int *)(im+2));
        t4=t3&7;
        t3=t3*2+8-t4;
        t5=0;
        for(i=0;i<5;i++)
        {
                t4=CSStab2[t2]^CSStab3[t1];
                t2=t1>>1;
                t1=((t1&1)<<8)^t4;
                t4=CSStab4[t4];
                t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
                t3=(t3<<8)|t6;
                t6=CSStab4[t6];
                t5+=t6+t4;
                k[i]=t5&0xff;
                t5>>=8;
        }
        for(i=9;i>=0;i--)
                key[CSStab0[i+1]]=k[CSStab0[i+1]]^CSStab1[key[CSStab0[i+1]]]^key[CSStab0[i]];
}

void CSStitlekey2(unsigned char *key,unsigned char *im)
{
        unsigned int t1,t2,t3,t4,t5,t6;
        unsigned char k[5];
        int i;

        t1=im[0]|0x100;
        t2=im[1];
        t3=*((unsigned int *)(im+2));
        t4=t3&7;
        t3=t3*2+8-t4;
        t5=0;
        for(i=0;i<5;i++)
        {
                t4=CSStab2[t2]^CSStab3[t1];
                t2=t1>>1;
                t1=((t1&1)<<8)^t4;
                t4=CSStab4[t4];
                t6=(((((((t3>>3)^t3)>>1)^t3)>>8)^t3)>>5)&0xff;
                t3=(t3<<8)|t6;
                t6=CSStab5[t6];
                t5+=t6+t4;
                k[i]=t5&0xff;
                t5>>=8;
        }
        for(i=9;i>=0;i--)
                key[CSStab0[i+1]]=k[CSStab0[i+1]]^CSStab1[key[CSStab0[i+1]]]^key[CSStab0[i]];
}

void CSSdecrypttitlekey(unsigned char *tkey,unsigned char *dkey)
{
        int i;
        unsigned char im1[6];
        unsigned char im2[6]={0x51,0x67,0x67,0xc5,0xe0,0x00};
        
        for(i=0;i<6;i++)
                im1[i]=dkey[i];

        CSStitlekey1(im1,im2);
        CSStitlekey2(tkey,im1);
}