Commit bd40826d authored by jan.koester's avatar jan.koester
Browse files

test

parent b319f69e

src/crypto/curve25519.cpp

+20 −52
Original line number Diff line number Diff line
@@ -130,32 +130,24 @@ void FieldElement::from_bytes(std::vector<uint8_t> in){ 
}



std::vector<uint8_t> FieldElement::to_bytes() const {

    FieldElement t = *this;

    FieldElement m;



    // 3 carries wie in ref10

    t.carry25519();

    t.carry25519();

    t.carry25519();



    for (int j = 0; j < 2; ++j) {

       std::vector <uint8_t> out(32,0);

        int carry;

        FieldElement m,t=*this;

        t.carry25519(); t.carry25519(); t.carry25519();

        for(size_t j=0; j<2; ++j){

            m.limbs[0]=t.limbs[0]-0xFFED;

        for (int i = 1; i < 15; ++i) {

            for(size_t i=1; i< 15; i++){

                m.limbs[i]=t.limbs[i]-0xFFFF-((m.limbs[i-1]>>16) & 1);

                m.limbs[i-1]&=0xFFFF;

            }

            m.limbs[15]=t.limbs[15]-0x7FFF-((m.limbs[14]>>16) &1);

        int carry = (m.limbs[15] >> 16) & 1;

            carry=(m.limbs[15]>>16) & 1;

            m.limbs[14] &=0xFFFF;



        // constant-time select:

        t.sel25519(m, 1 - carry);

            t.cswap(m,1-carry);

        }



    std::vector<uint8_t> out(32);

    for (int i = 0; i < 16; ++i) {

        out[2*i]     = (uint8_t)(t.limbs[i] & 0xFF);

        out[2*i + 1] = (uint8_t)((t.limbs[i] >> 8) & 0xFF);

        for(size_t i = 0; i <16; ++i){

            out[2*i] = t.limbs[i] & 0xFF;

            out[2*i+1] = t.limbs[i] >> 8;

        }

        return out;

}
@@ -189,30 +181,6 @@ bool scalarmult_curve25519(std::vector<uint8_t> &out, 
                           const std::vector<uint8_t> &scalar,

                           const std::vector<uint8_t> &point_u) {



    auto pack = [&](std::vector<uint8_t> &out,const FieldElement &in){

        out.resize(32);

        int carry;

        FieldElement m,t;

        for(size_t i=0; i <16; ++i){

            t.limbs[i]=in.limbs[i];

        }

        t.carry25519(); t.carry25519(); t.carry25519();

        for(size_t j=0; j<2; ++j){

            m.limbs[0]=t.limbs[0]-0xFFED;

            for(size_t i=1; i< 15; i++){

                m.limbs[i]=t.limbs[i]-0xFFFF-((m.limbs[i-1]>>16) & 1);

                m.limbs[i-1]&=0xFFFF;

            }

            m.limbs[15]=t.limbs[15]-0x7FFF-((m.limbs[14]>>16) &1);

            carry=(m.limbs[15]>>16) & 1;

            m.limbs[14] &=0xFFFF;

            t.cswap(m,1-carry);

        }

        for(size_t i = 0; i <16; ++i){

            out[2*i] = t.limbs[i] & 0xFF;

            out[2*i+1] = t.limbs[i] >> 8;

        }

    };

    std::array<uint8_t,32> clamped;

    FieldElement _12665;

    _12665.limbs={0xDB41,1};
@@ -263,7 +231,7 @@ bool scalarmult_curve25519(std::vector<uint8_t> &out, 


    c=c.invert();

    a=a*c;

    pack(out,a);

    out=a.to_bytes();

    return true;

}