semihonest_gen.h

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#ifndef SEMIHONEST_GEN_H__
#define SEMIHONEST_GEN_H__
#include <emp-tool/emp-tool.h>
#include <emp-ot/emp-ot.h>
#include <iostream>

template<typename T>
void gen_feed(Backend* be, int party, block * label, const bool*, int length);
template<typename T>
void gen_reveal(Backend* be, bool* clear, int party, const block * label, int length);

template<typename T>
class SemiHonestGen: public Backend { public:
    NetIO* io;
    SHOTIterated * ot;
    PRG prg;
    HalfGateGen<T> * gc;
    SemiHonestGen(NetIO* io, HalfGateGen<T>* gc): Backend(ALICE) {
        this->io = io;
        ot = new SHOTIterated(io, true);

        this->gc = gc;  
        Feed_internal = gen_feed<T>;
        Reveal_internal = gen_reveal<T>;
    }

    ~SemiHonestGen() {
        delete ot;
    }
};

template<typename T>
void gen_feed(Backend* be, int party, block * label, const bool* b, int length) {
    SemiHonestGen<T> * backend = (SemiHonestGen<T>*)(be);
    if(party == ALICE) {
        backend->prg.random_block(label, length);
        for (int i = 0; i < length; ++i) {
            block tosend = label[i];
            if(b[i]) tosend = xorBlocks(tosend, backend->gc->delta);
            backend->io->send_block(&tosend, 1);
        }
    } else {
        backend->ot->send_cot(label, backend->gc->delta, length);
    }
}

template<typename T>
void gen_reveal(Backend* be, bool* b, int party, const block * label, int length) {
    SemiHonestGen<T> * backend = (SemiHonestGen<T>*)(be);
    for (int i = 0; i < length; ++i) {
        if(isOne(&label[i]))
            b[i] = true;
        else if (isZero(&label[i]))
            b[i] = false;
        else {
            if (party == BOB or party == PUBLIC) {
                backend->io->send_block(&label[i], 1);
                b[i] = false;
            } else if(party == ALICE) {
                block tmp;
                backend->io->recv_block(&tmp, 1);
                b[i] = !(block_cmp(&tmp, &label[i], 1));
            }
        }
    }
    if(party == PUBLIC)
        backend->io->recv_data(b, length);
}
#endif //SEMIHONEST_GEN_H__