diff options
Diffstat (limited to 'src/math/gfpmath/point_gfp.cpp')
| -rw-r--r-- | src/math/gfpmath/point_gfp.cpp | 707 |
1 files changed, 153 insertions, 554 deletions
diff --git a/src/math/gfpmath/point_gfp.cpp b/src/math/gfpmath/point_gfp.cpp index f95add9f7..4b2de7913 100644 --- a/src/math/gfpmath/point_gfp.cpp +++ b/src/math/gfpmath/point_gfp.cpp @@ -13,295 +13,114 @@ namespace Botan { // construct the point at infinity or a random point -PointGFp::PointGFp(const CurveGFp& curve) - : mC(curve), - mX(curve.get_p(), 0), - mY(curve.get_p(), 1), - mZ(curve.get_p(), 0), - mZpow2(curve.get_p(),0), - mZpow3(curve.get_p(),0), - mAZpow4(curve.get_p(),0), - mZpow2_set(false), - mZpow3_set(false), - mAZpow4_set(false) +PointGFp::PointGFp(const CurveGFp& curve) : + mC(curve), + mX(curve.get_p(), 0), + mY(curve.get_p(), 1), + mZ(curve.get_p(), 0) { - // first set the point wide pointer - - set_shrd_mod(mC.get_ptr_mod()); - } // construct a point given its jacobian projective coordinates PointGFp::PointGFp(const CurveGFp& curve, const GFpElement& x, - const GFpElement& y, const GFpElement& z) - : mC(curve), - mX(x), - mY(y), - mZ(z), - mZpow2(curve.get_p(),0), - mZpow3(curve.get_p(),0), - mAZpow4(curve.get_p(),0), - mZpow2_set(false), - mZpow3_set(false), - mAZpow4_set(false) - { - set_shrd_mod(mC.get_ptr_mod()); - } -PointGFp::PointGFp ( const CurveGFp& curve, const GFpElement& x, - const GFpElement& y ) - :mC(curve), - mX(x), - mY(y), - mZ(curve.get_p(),1), - mZpow2(curve.get_p(),0), - mZpow3(curve.get_p(),0), - mAZpow4(curve.get_p(),0), - mZpow2_set(false), - mZpow3_set(false), - mAZpow4_set(false) - { - set_shrd_mod(mC.get_ptr_mod()); - } - -// copy constructor -PointGFp::PointGFp(const PointGFp& other) - : mC(other.mC), - mX(other.mX), - mY(other.mY), - mZ(other.mZ), - mZpow2(other.mZpow2), - mZpow3(other.mZpow3), - mAZpow4(other.mAZpow4), - mZpow2_set(other.mZpow2_set), - mZpow3_set(other.mZpow3_set), - mAZpow4_set(other.mAZpow4_set) + const GFpElement& y, const GFpElement& z) : + mC(curve), + mX(x), + mY(y), + mZ(z) { - set_shrd_mod(mC.get_ptr_mod()); } -// assignment operator -const PointGFp& PointGFp::operator=(PointGFp const& other) +PointGFp::PointGFp(const CurveGFp& curve, + const GFpElement& x, + const GFpElement& y) : + mC(curve), + mX(x), + mY(y), + mZ(curve.get_p(),1) { - mC = other.get_curve(); - mX = other.get_jac_proj_x(); - mY = other.get_jac_proj_y(); - mZ = other.get_jac_proj_z(); - mZpow2 = GFpElement(other.mZpow2); - mZpow3 = GFpElement(other.mZpow3); - mAZpow4 = GFpElement(other.mAZpow4); - mZpow2_set = other.mZpow2_set; - mZpow3_set = other.mZpow3_set; - mAZpow4_set = other.mAZpow4_set; - set_shrd_mod(mC.get_ptr_mod()); - return *this; - } - -const PointGFp& PointGFp::assign_within_same_curve(PointGFp const& other) - { - mX = other.get_jac_proj_x(); - mY = other.get_jac_proj_y(); - mZ = other.get_jac_proj_z(); - mZpow2_set = false; - mZpow3_set = false; - mAZpow4_set = false; - // the rest stays! - return *this; - } - -void PointGFp::set_shrd_mod(std::tr1::shared_ptr<GFpModulus> p_mod) - { - mX.set_shrd_mod(p_mod); - mY.set_shrd_mod(p_mod); - mZ.set_shrd_mod(p_mod); - mZpow2.set_shrd_mod(p_mod); - mZpow3.set_shrd_mod(p_mod); - mAZpow4.set_shrd_mod(p_mod); - } - -void PointGFp::ensure_worksp() const - { - if (mp_worksp_gfp_el.get() != 0) - { - if ((*mp_worksp_gfp_el).size() == GFPEL_WKSP_SIZE) - { - return; - } - else - { - throw Invalid_State("encountered incorrect size for PointGFp´s GFpElement workspace"); - } - } - - mp_worksp_gfp_el = std::tr1::shared_ptr<std::vector<GFpElement> >(new std::vector<GFpElement>); - mp_worksp_gfp_el->reserve(9); - for (u32bit i=0; i<GFPEL_WKSP_SIZE; i++) - { - mp_worksp_gfp_el->push_back(GFpElement(1,0)); - - } } // arithmetic operators PointGFp& PointGFp::operator+=(const PointGFp& rhs) { - if (is_zero()) + if(is_zero()) { *this = rhs; return *this; } - if (rhs.is_zero()) + if(rhs.is_zero()) { return *this; } - ensure_worksp(); - - if (rhs.mZ == *(mC.get_mres_one())) - { - //U1 = mX; - (*mp_worksp_gfp_el)[0].share_assign(mX); - - //S1 = mY; - (*mp_worksp_gfp_el)[2].share_assign(mY); - } - else - { - if ((!rhs.mZpow2_set) || (!rhs.mZpow3_set)) - { - rhs.mZpow2 = rhs.mZ; - rhs.mZpow2 *= rhs.mZ; - rhs.mZpow3 = rhs.mZpow2; - rhs.mZpow3 *= rhs.mZ; - - rhs.mZpow2_set = true; - rhs.mZpow3_set = true; - } - //U1 = mX * rhs.mZpow2; - (*mp_worksp_gfp_el)[0].share_assign(mX); - (*mp_worksp_gfp_el)[0] *= rhs.mZpow2; - //S1 = mY * rhs.mZpow3; - (*mp_worksp_gfp_el)[2].share_assign(mY); - (*mp_worksp_gfp_el)[2] *= rhs.mZpow3; + GFpElement U1 = mX; + GFpElement S1 = mY; - } - if (mZ == *(mC.get_mres_one())) + if(rhs.mZ != mC.get_mres_one()) { - //U2 = rhs.mX; - (*mp_worksp_gfp_el)[1].share_assign(rhs.mX); + GFpElement rhs_z2 = rhs.mZ * rhs.mZ; - //S2 = rhs.mY; - (*mp_worksp_gfp_el)[3].share_assign(rhs.mY); + U1 *= rhs_z2; + S1 *= rhs_z2 * rhs.mZ; } - else - { - if ((!mZpow2_set) || (!mZpow3_set)) - { - // precomputation can´t be used, because *this changes anyway - mZpow2 = mZ; - mZpow2 *= mZ; - mZpow3 = mZpow2; - mZpow3 *= mZ; - } - //U2 = rhs.mX * mZpow2; - (*mp_worksp_gfp_el)[1].share_assign(rhs.mX); - (*mp_worksp_gfp_el)[1] *= mZpow2; + GFpElement U2 = rhs.mX; + GFpElement S2 = rhs.mY; - //S2 = rhs.mY * mZpow3; - (*mp_worksp_gfp_el)[3].share_assign(rhs.mY); - (*mp_worksp_gfp_el)[3] *= mZpow3; + if(mZ != mC.get_mres_one()) + { + GFpElement lhs_z2 = mZ * mZ; + U2 *= lhs_z2; + S2 *= lhs_z2 * mZ; } - //GFpElement H(U2 - U1); - - (*mp_worksp_gfp_el)[4].share_assign((*mp_worksp_gfp_el)[1]); - (*mp_worksp_gfp_el)[4] -= (*mp_worksp_gfp_el)[0]; - //GFpElement r(S2 - S1); - (*mp_worksp_gfp_el)[5].share_assign((*mp_worksp_gfp_el)[3]); - (*mp_worksp_gfp_el)[5] -= (*mp_worksp_gfp_el)[2]; - - //if(H.is_zero()) - if ((*mp_worksp_gfp_el)[4].is_zero()) + GFpElement H(U2 - U1); + GFpElement r(S2 - S1); + if(H.is_zero()) { - if ((*mp_worksp_gfp_el)[5].is_zero()) - + if(r.is_zero()) { mult2_in_place(); return *this; } + *this = PointGFp(mC); // setting myself to zero return *this; } - //U2 = H * H; - (*mp_worksp_gfp_el)[1].share_assign((*mp_worksp_gfp_el)[4]); - (*mp_worksp_gfp_el)[1] *= (*mp_worksp_gfp_el)[4]; + U2 = H * H; - //S2 = U2 * H; - (*mp_worksp_gfp_el)[3].share_assign((*mp_worksp_gfp_el)[1]); - (*mp_worksp_gfp_el)[3] *= (*mp_worksp_gfp_el)[4]; + S2 = U2 * H; - //U2 *= U1; - (*mp_worksp_gfp_el)[1] *= (*mp_worksp_gfp_el)[0]; + U2 *= U1; - //GFpElement x(r*r - S2 - (U2+U2)); - (*mp_worksp_gfp_el)[6].share_assign((*mp_worksp_gfp_el)[5]); - (*mp_worksp_gfp_el)[6] *= (*mp_worksp_gfp_el)[5]; - (*mp_worksp_gfp_el)[6] -= (*mp_worksp_gfp_el)[3]; - (*mp_worksp_gfp_el)[6] -= (*mp_worksp_gfp_el)[1]; - (*mp_worksp_gfp_el)[6] -= (*mp_worksp_gfp_el)[1]; + GFpElement x(r*r - S2 - (U2+U2)); - //GFpElement z(S1 * S2); - (*mp_worksp_gfp_el)[8].share_assign((*mp_worksp_gfp_el)[2]); - (*mp_worksp_gfp_el)[8] *= (*mp_worksp_gfp_el)[3]; + GFpElement z(S1 * S2); - //GFpElement y(r * (U2-x) - z); - (*mp_worksp_gfp_el)[7].share_assign((*mp_worksp_gfp_el)[1]); - (*mp_worksp_gfp_el)[7] -= (*mp_worksp_gfp_el)[6]; - (*mp_worksp_gfp_el)[7] *= (*mp_worksp_gfp_el)[5]; - (*mp_worksp_gfp_el)[7] -= (*mp_worksp_gfp_el)[8]; + GFpElement y(r * (U2-x) - z); - if (mZ == *(mC.get_mres_one())) + if(mZ == mC.get_mres_one()) { - if (rhs.mZ != *(mC.get_mres_one())) - { - //z = rhs.mZ * H; - (*mp_worksp_gfp_el)[8].share_assign(rhs.mZ); - (*mp_worksp_gfp_el)[8] *= (*mp_worksp_gfp_el)[4]; - } + if(rhs.mZ != mC.get_mres_one()) + z = rhs.mZ * H; else - { - //z = H; - (*mp_worksp_gfp_el)[8].share_assign((*mp_worksp_gfp_el)[4]); - } + z = H; } - else if (rhs.mZ != *(mC.get_mres_one())) + else if(rhs.mZ != mC.get_mres_one()) { - //U1 = mZ * rhs.mZ; - (*mp_worksp_gfp_el)[0].share_assign(mZ); - (*mp_worksp_gfp_el)[0] *= rhs.mZ; - - //z = U1 * H; - (*mp_worksp_gfp_el)[8].share_assign((*mp_worksp_gfp_el)[0]); - (*mp_worksp_gfp_el)[8] *= (*mp_worksp_gfp_el)[4]; - + U1 = mZ * rhs.mZ; + z = U1 * H; } else - { - //z = mZ * H; - (*mp_worksp_gfp_el)[8].share_assign(mZ); - (*mp_worksp_gfp_el)[8] *= (*mp_worksp_gfp_el)[4]; + z = mZ * H; - } - mZpow2_set = false; - mZpow3_set = false; - mAZpow4_set = false; - - mX = (*mp_worksp_gfp_el)[6]; - mY = (*mp_worksp_gfp_el)[7]; - mZ = (*mp_worksp_gfp_el)[8]; + mX = x; + mY = y; + mZ = z; return *this; @@ -310,7 +129,7 @@ PointGFp& PointGFp::operator-=(const PointGFp& rhs) { PointGFp minus_rhs = PointGFp(rhs).negate(); - if (is_zero()) + if(is_zero()) { *this = minus_rhs; } @@ -336,92 +155,39 @@ PointGFp& PointGFp::mult_this_secure(const BigInt& scalar, // use montgomery mult. in this operation this->turn_on_sp_red_mul(); - std::tr1::shared_ptr<PointGFp> H(new PointGFp(this->mC)); - std::tr1::shared_ptr<PointGFp> tmp; // used for AADA + PointGFp H(mC); PointGFp P(*this); BigInt m(scalar); - if (m < BigInt(0)) + if(m < BigInt(0)) { m = -m; P.negate(); } - if (P.is_zero() || (m == BigInt(0))) + if(P.is_zero() || (m == BigInt(0))) { - *this = *H; + *this = H; return *this; } - if (m == BigInt(1)) - { + if(m == BigInt(1)) return *this; - } - // -#ifdef CM_AADA -#ifndef CM_RAND_EXP - int max_secr_bits = max_secr.bits(); -#endif -#endif - - int mul_bits = m.bits(); // this is used for a determined number of loop runs in - // the mult_loop where leading zero´s are padded if necessary. - // Here we assign the value that will be used when no countermeasures are specified -#ifdef CM_RAND_EXP - u32bit rand_r_bit_len = 20; // Coron(99) proposes 20 bit for r -#ifdef CM_AADA + int mul_bits = m.bits(); - BigInt r_max(1); - -#endif // CM_AADA - - // use randomized exponent -#ifdef TA_COLL_T - static BigInt r_randexp; - if (new_rand) + for(int i = mul_bits - 1; i >= 0; i--) { - r_randexp = random_integer(rand_r_bit_len); - } - //assert(!r_randexp.is_zero()); -#else - BigInt r_randexp(random_integer(rand_r_bit_len)); -#endif - - m += r_randexp * point_order; - // determine mul_bits... -#ifdef CM_AADA - // AADA with rand. Exp. - //assert(rand_r_bit_len > 0); - r_max <<= rand_r_bit_len; - r_max -= 1; - //assert(r_max.bits() == rand_r_bit_len); - mul_bits = (max_secr + point_order * r_max).bits(); -#else - // rand. Exp. without AADA - mul_bits = m.bits(); -#endif // CM_AADA - - -#endif // CM_RAND_EXP - - // determine mul_bits... -#if (CM_AADA == 1 && CM_RAND_EXP != 1) - - mul_bits = max_secr_bits; -#endif // CM_AADA without CM_RAND_EXP - - //assert(mul_bits != 0); + H.mult2_in_place(); + if(m.get_bit(i)) + H += P; + } - H = mult_loop(mul_bits-1, m, H, tmp, P); + if(!H.is_zero()) // cannot convert if H == O + *this = H.get_z_to_one(); + else + *this = H; - if (!H->is_zero()) // cannot convert if H == O - { - *this = H->get_z_to_one(); - }else - { - *this = *H; - } mX.turn_off_sp_red_mul(); mY.turn_off_sp_red_mul(); mZ.turn_off_sp_red_mul(); @@ -439,226 +205,100 @@ PointGFp& PointGFp::operator*=(const BigInt& scalar) PointGFp P(*this); P.turn_on_sp_red_mul(); BigInt m(scalar); - if (m < BigInt(0)) + + if(m < BigInt(0)) { m = -m; P.negate(); } - if (P.is_zero() || (m == BigInt(0))) + + if(P.is_zero() || (m == BigInt(0))) { *this = H; return *this; } - if (m == BigInt(1)) - { - //*this == P already + + if(m == BigInt(1)) //*this == P already return *this; - } const int l = m.bits() - 1; - for (int i=l; i >=0; i--) + for(int i = l; i >= 0; --i) { - H.mult2_in_place(); - if (m.get_bit(i)) - { + if(m.get_bit(i)) H += P; - } } - if (!H.is_zero()) // cannot convert if H == O - { + if(!H.is_zero()) // cannot convert if H == O *this = H.get_z_to_one(); - }else - { + else *this = H; - } - return *this; - } - -inline std::tr1::shared_ptr<PointGFp> PointGFp::mult_loop(int l, - const BigInt& m, - std::tr1::shared_ptr<PointGFp> H, - std::tr1::shared_ptr<PointGFp> tmp, - const PointGFp& P) - { - //assert(l >= (int)m.bits()- 1); - tmp = H; - std::tr1::shared_ptr<PointGFp> to_add(new PointGFp(P)); // we just need some point - // so that we can use op= - // inside the loop - for (int i=l; i >=0; i--) - { - H->mult2_in_place(); - -#ifndef CM_AADA - - if (m.get_bit(i)) - { - *H += P; - } -#else // (CM_AADA is in) - - if (H.get() == to_add.get()) - { - to_add = tmp; // otherwise all pointers might point to the same object - // and we always need two objects to be able to switch around - } - to_add->assign_within_same_curve(*H); - tmp = H; - *tmp += P; // tmp already points to H - - if (m.get_bit(i)) - { - H = tmp; // NOTE: assign the pointer, not the value! - // (so that the operation is fast and thus as difficult - // to detect as possible) - } - else - { - H = to_add; // NOTE: this is necessary, because the assignment - // "*tmp = ..." already changed what H pointed to - - - } -#endif // CM_AADA - } - return H; + return *this; } PointGFp& PointGFp::negate() { - if (!is_zero()) - { + if(!is_zero()) mY.negate(); - } + return *this; } // *this *= 2 PointGFp& PointGFp::mult2_in_place() { - if (is_zero()) - { + if(is_zero()) return *this; - } - if (mY.is_zero()) + else if(mY.is_zero()) { - *this = PointGFp(mC); // setting myself to zero return *this; } - ensure_worksp(); - (*mp_worksp_gfp_el)[0].share_assign(mY); - (*mp_worksp_gfp_el)[0] *= mY; + GFpElement Y_squared = mY*mY; - //GFpElement S(mX * z); - (*mp_worksp_gfp_el)[1].share_assign(mX); - (*mp_worksp_gfp_el)[1] *= (*mp_worksp_gfp_el)[0]; + GFpElement S = mX * Y_squared; - //GFpElement x(S + S); - (*mp_worksp_gfp_el)[2].share_assign((*mp_worksp_gfp_el)[1]); - (*mp_worksp_gfp_el)[2] += (*mp_worksp_gfp_el)[1]; + GFpElement x = S + S; - //S = x + x; - (*mp_worksp_gfp_el)[1].share_assign((*mp_worksp_gfp_el)[2]); - (*mp_worksp_gfp_el)[1] += (*mp_worksp_gfp_el)[2]; + S = x + x; - if (!mAZpow4_set) + GFpElement a_z4 = mC.get_mres_a(); + if(mZ != mC.get_mres_one()) { - if (mZ == *(mC.get_mres_one())) - { - mAZpow4 = mC.get_mres_a(); - mAZpow4_set = true; - } - else - { - if (!mZpow2_set) - { - mZpow2 = mZ; - mZpow2 *= mZ; + GFpElement z2 = mZ * mZ; + a_z4 *= z2; + a_z4 *= z2; + } - mZpow2_set = true; - } - //x = mZpow2 * mZpow2; - (*mp_worksp_gfp_el)[2].share_assign(mZpow2); - (*mp_worksp_gfp_el)[2] *= mZpow2; + GFpElement y(mX * mX); - //mAZpow4 = mC.get_mres_a() * x; - mAZpow4 = mC.get_mres_a(); - mAZpow4 *= (*mp_worksp_gfp_el)[2]; + GFpElement M(y + y + y + a_z4); - } + x = M * M - (S+S); - } + y = Y_squared * Y_squared; - //GFpElement y(mX * mX); - (*mp_worksp_gfp_el)[3].share_assign(mX); - (*mp_worksp_gfp_el)[3] *= mX; - - //GFpElement M(y + y + y + mAZpow4); - (*mp_worksp_gfp_el)[4].share_assign((*mp_worksp_gfp_el)[3]); - (*mp_worksp_gfp_el)[4] += (*mp_worksp_gfp_el)[3]; - (*mp_worksp_gfp_el)[4] += (*mp_worksp_gfp_el)[3]; - (*mp_worksp_gfp_el)[4] += mAZpow4; - - //x = M * M - (S+S); - (*mp_worksp_gfp_el)[2].share_assign((*mp_worksp_gfp_el)[4]); - (*mp_worksp_gfp_el)[2] *= (*mp_worksp_gfp_el)[4]; - (*mp_worksp_gfp_el)[2] -= (*mp_worksp_gfp_el)[1]; - (*mp_worksp_gfp_el)[2] -= (*mp_worksp_gfp_el)[1]; - - //y = z * z; - (*mp_worksp_gfp_el)[3].share_assign((*mp_worksp_gfp_el)[0]); - (*mp_worksp_gfp_el)[3] *= (*mp_worksp_gfp_el)[0]; - - //GFpElement U(y + y); - (*mp_worksp_gfp_el)[5].share_assign((*mp_worksp_gfp_el)[3]); - (*mp_worksp_gfp_el)[5] += (*mp_worksp_gfp_el)[3]; - - //z = U + U; - (*mp_worksp_gfp_el)[0].share_assign((*mp_worksp_gfp_el)[5]); - (*mp_worksp_gfp_el)[0] += (*mp_worksp_gfp_el)[5]; - - //U = z + z; - (*mp_worksp_gfp_el)[5].share_assign((*mp_worksp_gfp_el)[0]); - (*mp_worksp_gfp_el)[5] += (*mp_worksp_gfp_el)[0]; - - //y = M * (S - x) - U; - (*mp_worksp_gfp_el)[3].share_assign((*mp_worksp_gfp_el)[1]); - (*mp_worksp_gfp_el)[3] -= (*mp_worksp_gfp_el)[2]; - (*mp_worksp_gfp_el)[3] *= (*mp_worksp_gfp_el)[4]; - (*mp_worksp_gfp_el)[3] -= (*mp_worksp_gfp_el)[5]; - - if (mZ != *(mC.get_mres_one())) - { - //z = mY * mZ; - (*mp_worksp_gfp_el)[0].share_assign(mY); - (*mp_worksp_gfp_el)[0] *= mZ; + GFpElement U(y + y); - } + GFpElement z = U + U; + + U = z + z; + + y = M * (S - x) - U; + + if(mZ != mC.get_mres_one()) + z = mY * mZ; else - { - //z = mY; - (*mp_worksp_gfp_el)[0].share_assign(mY); + z = mY; + + z = z + z; + + mX = x; + mY = y; + mZ = z; - } - //z = z + z; - (*mp_worksp_gfp_el)[6].share_assign((*mp_worksp_gfp_el)[0]); - (*mp_worksp_gfp_el)[0] += (*mp_worksp_gfp_el)[6]; - - //mX = x; - //mY = y; - //mZ = z; - mX = (*mp_worksp_gfp_el)[2]; - mY = (*mp_worksp_gfp_el)[3]; - mZ = (*mp_worksp_gfp_el)[0]; - - mZpow2_set = false; - mZpow3_set = false; - mAZpow4_set = false; return *this; } @@ -676,19 +316,14 @@ void PointGFp::turn_on_sp_red_mul() const mX.get_mres(); mY.get_mres(); mZ.get_mres(); - - mZpow2.turn_on_sp_red_mul(); - mZpow3.turn_on_sp_red_mul(); - mAZpow4.turn_on_sp_red_mul(); } -// getters /** * returns a point equivalent to *this but were * Z has value one, i.e. x and y correspond to * their values in affine coordinates */ -PointGFp const PointGFp::get_z_to_one() const +PointGFp PointGFp::get_z_to_one() const { return PointGFp(*this).set_z_to_one(); } @@ -701,7 +336,7 @@ PointGFp const PointGFp::get_z_to_one() const */ const PointGFp& PointGFp::set_z_to_one() const { - if (!(mZ.get_value() == BigInt(1)) && !(mZ.get_value() == BigInt(0))) + if(!(mZ.get_value() == BigInt(1)) && !(mZ.get_value() == BigInt(0))) { GFpElement z = inverse(mZ); GFpElement z2 = z * z; @@ -714,7 +349,7 @@ const PointGFp& PointGFp::set_z_to_one() const } else { - if (mZ.get_value() == BigInt(0)) + if(mZ.get_value() == BigInt(0)) { throw Illegal_Transformation("cannot convert Z to one"); } @@ -722,58 +357,35 @@ const PointGFp& PointGFp::set_z_to_one() const return *this; // mZ = 1 already } -const CurveGFp PointGFp::get_curve() const +GFpElement PointGFp::get_affine_x() const { - return mC; - } - -GFpElement const PointGFp::get_affine_x() const - { - - if (is_zero()) - { + if(is_zero()) throw Illegal_Transformation("cannot convert to affine"); - } - /*if(!mZpow2_set) - {*/ - mZpow2 = mZ * mZ; - mZpow2_set = true; - //} - //assert(mZpow2 == mZ*mZ); - GFpElement z2 = mZpow2; + GFpElement z2 = mZ * mZ; return mX * z2.inverse_in_place(); } -GFpElement const PointGFp::get_affine_y() const +GFpElement PointGFp::get_affine_y() const { - - if (is_zero()) - { + if(is_zero()) throw Illegal_Transformation("cannot convert to affine"); - } - /*if(!mZpow3_set ) - {*/ - mZpow3 = mZ * mZ * mZ; - mZpow3_set = true; - //} - //assert(mZpow3 == mZ * mZ *mZ); - GFpElement z3 = mZpow3; + GFpElement z3 = mZ * mZ * mZ; return mY * z3.inverse_in_place(); } -GFpElement const PointGFp::get_jac_proj_x() const +GFpElement PointGFp::get_jac_proj_x() const { return GFpElement(mX); } -GFpElement const PointGFp::get_jac_proj_y() const +GFpElement PointGFp::get_jac_proj_y() const { return GFpElement(mY); } -GFpElement const PointGFp::get_jac_proj_z() const +GFpElement PointGFp::get_jac_proj_z() const { return GFpElement(mZ); } @@ -794,14 +406,14 @@ bool PointGFp::is_zero() const void PointGFp::check_invariants() const { - if (is_zero()) + if(is_zero()) { return; } const GFpElement y2 = mY * mY; const GFpElement x3 = mX * mX * mX; - if (mZ.get_value() == BigInt(1)) + if(mZ.get_value() == BigInt(1)) { GFpElement ax = mC.get_a() * mX; if(y2 != (x3 + ax + mC.get_b())) @@ -811,16 +423,13 @@ void PointGFp::check_invariants() const } - mZpow2 = mZ * mZ; - mZpow2_set = true; - mZpow3 = mZpow2 * mZ; - mZpow3_set = true; - mAZpow4 = mZpow3 * mZ * mC.get_a(); - mAZpow4_set = true; - const GFpElement aXZ4 = mAZpow4 * mX; - const GFpElement bZ6 = mC.get_b() * mZpow3 * mZpow3; + GFpElement Zpow2 = mZ * mZ; + GFpElement Zpow3 = Zpow2 * mZ; + GFpElement AZpow4 = Zpow3 * mZ * mC.get_a(); + const GFpElement aXZ4 = AZpow4 * mX; + const GFpElement bZ6 = mC.get_b() * Zpow3 * Zpow3; - if (y2 != (x3 + aXZ4 + bZ6)) + if(y2 != (x3 + aXZ4 + bZ6)) throw Illegal_Point(); } @@ -831,12 +440,6 @@ void PointGFp::swap(PointGFp& other) mX.swap(other.mX); mY.swap(other.mY); mZ.swap(other.mZ); - mZpow2.swap(other.mZpow2); - mZpow3.swap(other.mZpow3); - mAZpow4.swap(other.mAZpow4); - std::swap<bool>(mZpow2_set, other.mZpow2_set); - std::swap<bool>(mZpow3_set, other.mZpow3_set); - std::swap<bool>(mAZpow4_set, other.mAZpow4_set); } PointGFp mult2(const PointGFp& point) @@ -846,11 +449,11 @@ PointGFp mult2(const PointGFp& point) bool operator==(const PointGFp& lhs, PointGFp const& rhs) { - if (lhs.is_zero() && rhs.is_zero()) + if(lhs.is_zero() && rhs.is_zero()) { return true; } - if ((lhs.is_zero() && !rhs.is_zero()) || (!lhs.is_zero() && rhs.is_zero())) + if((lhs.is_zero() && !rhs.is_zero()) || (!lhs.is_zero() && rhs.is_zero())) { return false; } @@ -906,22 +509,22 @@ PointGFp mult_point_secure(const PointGFp& point, const BigInt& scalar, SecureVector<byte> EC2OSP(const PointGFp& point, byte format) { SecureVector<byte> result; - if (format == PointGFp::UNCOMPRESSED) + if(format == PointGFp::UNCOMPRESSED) { result = encode_uncompressed(point); } - else if (format == PointGFp::COMPRESSED) + else if(format == PointGFp::COMPRESSED) { result = encode_compressed(point); } - else if (format == PointGFp::HYBRID) + else if(format == PointGFp::HYBRID) { result = encode_hybrid(point); } else { - throw Format_Error("illegal point encoding format specification"); + throw Invalid_Argument("illegal point encoding format specification"); } return result; } @@ -929,7 +532,7 @@ SecureVector<byte> encode_compressed(const PointGFp& point) { - if (point.is_zero()) + if(point.is_zero()) { SecureVector<byte> result (1); result[0] = 0; @@ -938,7 +541,7 @@ SecureVector<byte> encode_compressed(const PointGFp& point) } u32bit l = point.get_curve().get_p().bits(); int dummy = l & 7; - if (dummy != 0) + if(dummy != 0) { l += 8 - dummy; } @@ -949,7 +552,7 @@ SecureVector<byte> encode_compressed(const PointGFp& point) SecureVector<byte> bX = BigInt::encode_1363(x, l); result.copy(1, bX.begin(), bX.size()); BigInt y = point.get_affine_y().get_value(); - if (y.get_bit(0)) + if(y.get_bit(0)) { result[0] |= 1; } @@ -959,7 +562,7 @@ SecureVector<byte> encode_compressed(const PointGFp& point) SecureVector<byte> encode_uncompressed(const PointGFp& point) { - if (point.is_zero()) + if(point.is_zero()) { SecureVector<byte> result (1); result[0] = 0; @@ -967,7 +570,7 @@ SecureVector<byte> encode_uncompressed(const PointGFp& point) } u32bit l = point.get_curve().get_p().bits(); int dummy = l & 7; - if (dummy != 0) + if(dummy != 0) { l += 8 - dummy; } @@ -986,7 +589,7 @@ SecureVector<byte> encode_uncompressed(const PointGFp& point) SecureVector<byte> encode_hybrid(const PointGFp& point) { - if (point.is_zero()) + if(point.is_zero()) { SecureVector<byte> result (1); result[0] = 0; @@ -994,7 +597,7 @@ SecureVector<byte> encode_hybrid(const PointGFp& point) } u32bit l = point.get_curve().get_p().bits(); int dummy = l & 7; - if (dummy != 0) + if(dummy != 0) { l += 8 - dummy; } @@ -1007,7 +610,7 @@ SecureVector<byte> encode_hybrid(const PointGFp& point) SecureVector<byte> bY = BigInt::encode_1363(y, l); result.copy(1, bX.begin(), bX.size()); result.copy(l+1, bY.begin(), bY.size()); - if (y.get_bit(0)) + if(y.get_bit(0)) { result[0] |= 1; } @@ -1016,7 +619,7 @@ SecureVector<byte> encode_hybrid(const PointGFp& point) PointGFp OS2ECP(MemoryRegion<byte> const& os, const CurveGFp& curve) { - if (os.size() == 1 && os[0] == 0) + if(os.size() == 1 && os[0] == 0) { return PointGFp(curve); // return zero } @@ -1038,10 +641,6 @@ PointGFp OS2ECP(MemoryRegion<byte> const& os, const CurveGFp& curve) bX = SecureVector<byte>(os.size() - 1); bX.copy(os.begin()+1, os.size()-1); - /* Problem wäre, wenn decode() das erste bit als Vorzeichen interpretiert. - *--------------------- - * AW(FS): decode() interpretiert das erste Bit nicht als Vorzeichen - */ bi_dec_x = BigInt::decode(bX, bX.size()); x = GFpElement(curve.get_p(), bi_dec_x); bool yMod2; @@ -1072,13 +671,13 @@ PointGFp OS2ECP(MemoryRegion<byte> const& os, const CurveGFp& curve) bX.copy(os.begin() + 1, l); bY.copy(os.begin()+1+l, l); yMod2 = (pc & 0x01) == 1; - if (!(PointGFp::decompress(yMod2, x, curve) == y)) + if(!(PointGFp::decompress(yMod2, x, curve) == y)) { throw Illegal_Point("error during decoding hybrid format"); } break; default: - throw Format_Error("encountered illegal format specification while decoding point"); + throw Invalid_Argument("encountered illegal format specification while decoding point"); } z = GFpElement(curve.get_p(), BigInt(1)); //assert((x.is_trf_to_mres() && x.is_use_montgm()) || !x.is_trf_to_mres()); @@ -1107,7 +706,7 @@ GFpElement PointGFp::decompress(bool yMod2, const GFpElement& x, throw Illegal_Point("error during decompression"); bool zMod2 = z.get_bit(0); - if ((zMod2 && ! yMod2) || (!zMod2 && yMod2)) + if((zMod2 && ! yMod2) || (!zMod2 && yMod2)) { z = curve.get_p() - z; } |