D411 scramble

#include <stdio.h>

void printseed(unsigned char* data) {
    int i;
    for(i=1;i<16;i++) {
        printf("%x ", data[i]);
    }
    printf("\n");
}

void printstream(unsigned char* data, int restart) {
    int i;
    for(i=restart;i<16;i++) {
        printf("%d ", data[i]&1);
    }
    printf("\n");
}

void mangle(unsigned char* data) {
    unsigned char a,x,temp,i,offset,carry=0;
    a=data[0xf];
    do {
        x=a;
        offset=1;
        carry=1;
        a+=data[offset]+carry;
        data[offset]=a&0xf;
        a=data[offset++];
        a+=data[offset]+carry;
        a=(~a)&0xf;
        temp=a; a=data[offset]; data[offset++]=temp&0xf;
        a+=data[offset]+carry;
        if(a<0x10) {
            temp=a; a=data[offset]; data[offset++]=temp&0xf;
        }
        a+=data[offset];
        data[offset]=a&0xf;
        a=data[offset++];
        carry=0;
        a+=data[offset]+carry;
        temp=a; a=data[offset]; data[offset++]=temp&0xf;
        a+=8;
        if(a<0x10) {
            a+=data[offset]+carry;
        }
        temp=a; a=data[offset]; data[offset++]=temp&0xf;

        while(offset<0x10) {
            a++;
            a+=data[offset]+carry;
            data[offset]=a&0xf;
            a=data[offset++];
        }
        offset &= 0xf;
        a=x;
        a+=0xf;
        if(a>0x0f) {
                        a &= 0xf;
                        carry=1;
                } else carry=0;
    } while(carry);
}

int main(void) {
    unsigned char restart=1;
    unsigned char keyseed_data[16]= {0x0, // dummy
               0xb,0x1,0x4,0xf,
               0x4,0xb,0x5,0x7,
               0xf,0xd,0x6,0x1,
               0xe,0x9,0x8};
    unsigned char lockseed_data[16]={0x0, // dummy
               0x0,0x9,0xa,0x1,
               0x8,0x5,0xf,0x1,
               0x1,0xe,0x1,0x0,
               0xd,0xe,0xc};

    unsigned char* keyseed=keyseed_data;
    unsigned char* lockseed=lockseed_data;
    printseed(keyseed);
    printseed(lockseed);
    printf("\n");

    while(1) {
        printf("\n");
        printstream(keyseed, restart);
        printstream(lockseed, restart);
        mangle(keyseed);
        mangle(keyseed);
        mangle(keyseed);
        mangle(lockseed);
        mangle(lockseed);
        mangle(lockseed);

    //  printseed(keyseed);
    //  printseed(lockseed);
        restart=lockseed_data[7];
        if(lockseed_data[7]&1) {
            keyseed=lockseed_data;
            lockseed=keyseed_data;
        } else {
            keyseed=keyseed_data;
            lockseed=lockseed_data;
        }
        if(!restart)restart=1;
    //  printf("send %d-15\n", restart);
    }
    return 0;
}