diff options
author | lloyd <[email protected]> | 2010-02-24 02:18:55 +0000 |
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committer | lloyd <[email protected]> | 2010-02-24 02:18:55 +0000 |
commit | 6e50979c8d2a0635599228a2ae1a20d59b24a0c6 (patch) | |
tree | 587aaf6c20d45a6fa81ee180ca0aa533f51403d1 /src/math/gfpmath/gfp_element.cpp | |
parent | 888fc3d0f2f6f1dc5e9764e83e9b7fd64da916d8 (diff) | |
parent | 8c951ef2f1e54e1134e8db683662ec881df89c88 (diff) |
propagate from branch 'net.randombit.botan' (head 84baf58b29f3aaaee34e2b873d0040be5a6c4368)
to branch 'net.randombit.botan.gost_3410' (head 63cbe3e357c071d7960bfedc31101eff35895285)
Diffstat (limited to 'src/math/gfpmath/gfp_element.cpp')
-rw-r--r-- | src/math/gfpmath/gfp_element.cpp | 248 |
1 files changed, 55 insertions, 193 deletions
diff --git a/src/math/gfpmath/gfp_element.cpp b/src/math/gfpmath/gfp_element.cpp index 233f2e4cd..3bb4d0002 100644 --- a/src/math/gfpmath/gfp_element.cpp +++ b/src/math/gfpmath/gfp_element.cpp @@ -165,47 +165,20 @@ BigInt montg_trf_to_ordres(const BigInt& m_res, const BigInt& m, const BigInt& r } -GFpElement::GFpElement(const BigInt& p, const BigInt& value, bool use_montgm) - : mp_mod(), - m_value(value %p), - m_use_montgm(use_montgm), - m_is_trf(false) - { - assert(mp_mod.get() == 0); - mp_mod = std::tr1::shared_ptr<GFpModulus>(new GFpModulus(p)); - assert(mp_mod->m_p_dash == 0); +GFpElement::GFpElement(const BigInt& p, const BigInt& value, bool use_montgomery) + : modulus(p), m_value(value %p), m_use_montgm(use_montgomery), m_is_trf(false) + { if(m_use_montgm) ensure_montgm_precomp(); } -GFpElement::GFpElement(std::tr1::shared_ptr<GFpModulus> const mod, const BigInt& value, bool use_montgm) - : mp_mod(), - m_value(value % mod->m_p), - m_use_montgm(use_montgm), - m_is_trf(false) - { - assert(mp_mod.get() == 0); - mp_mod = mod; - } - -GFpElement::GFpElement(const GFpElement& other) - : m_value(other.m_value), - m_use_montgm(other.m_use_montgm), - m_is_trf(other.m_is_trf) - - { - //creates an independent copy - assert((other.m_is_trf && other.m_use_montgm) || !other.m_is_trf); - mp_mod.reset(new GFpModulus(*other.mp_mod)); // copy-ctor of GFpModulus - } - -void GFpElement::turn_on_sp_red_mul() const +void GFpElement::turn_on_sp_red_mul() { ensure_montgm_precomp(); m_use_montgm = true; } -void GFpElement::turn_off_sp_red_mul() const +void GFpElement::turn_off_sp_red_mul() { if(m_is_trf) { @@ -216,40 +189,25 @@ void GFpElement::turn_off_sp_red_mul() const m_use_montgm = false; } -void GFpElement::ensure_montgm_precomp() const +void GFpElement::ensure_montgm_precomp() { - if((!mp_mod->m_r.is_zero()) && (!mp_mod->m_r_inv.is_zero()) && (!mp_mod->m_p_dash.is_zero())) + if((!modulus.get_r().is_zero()) && (!modulus.get_r_inv().is_zero()) && (!modulus.get_p_dash().is_zero())) { // values are already set, nothing more to do } else { - BigInt tmp_r(montgm_calc_r_oddmod(mp_mod->m_p)); - - BigInt tmp_r_inv(inverse_mod(tmp_r, mp_mod->m_p)); + BigInt tmp_r(montgm_calc_r_oddmod(modulus.get_p())); - BigInt tmp_p_dash(montgm_calc_m_dash(tmp_r, mp_mod->m_p, tmp_r_inv)); + BigInt tmp_r_inv(inverse_mod(tmp_r, modulus.get_p())); - mp_mod->m_r.grow_reg(tmp_r.size()); - mp_mod->m_r_inv.grow_reg(tmp_r_inv.size()); - mp_mod->m_p_dash.grow_reg(tmp_p_dash.size()); + BigInt tmp_p_dash(montgm_calc_m_dash(tmp_r, modulus.get_p(), tmp_r_inv)); - mp_mod->m_r = tmp_r; - mp_mod->m_r_inv = tmp_r_inv; - mp_mod->m_p_dash = tmp_p_dash; - - assert(!mp_mod->m_r.is_zero()); - assert(!mp_mod->m_r_inv.is_zero()); - assert(!mp_mod->m_p_dash.is_zero()); + modulus.reset_values(tmp_p_dash, tmp_r, tmp_r_inv); } } -void GFpElement::set_shrd_mod(std::tr1::shared_ptr<GFpModulus> const p_mod) - { - mp_mod = p_mod; - } - void GFpElement::trf_to_mres() const { if(!m_use_montgm) @@ -257,27 +215,27 @@ void GFpElement::trf_to_mres() const throw Illegal_Transformation("GFpElement is not allowed to be transformed to m-residue"); } assert(m_is_trf == false); - assert(!mp_mod->m_r_inv.is_zero()); - assert(!mp_mod->m_p_dash.is_zero()); - m_value = montg_trf_to_mres(m_value, mp_mod->m_r, mp_mod->m_p); + assert(!modulus.get_r_inv().is_zero()); + assert(!modulus.get_p_dash().is_zero()); + m_value = montg_trf_to_mres(m_value, modulus.get_r(), modulus.get_p()); m_is_trf = true; } void GFpElement::trf_to_ordres() const { assert(m_is_trf == true); - m_value = montg_trf_to_ordres(m_value, mp_mod->m_p, mp_mod->m_r_inv); + m_value = montg_trf_to_ordres(m_value, modulus.get_p(), modulus.get_r_inv()); m_is_trf = false; } bool GFpElement::align_operands_res(const GFpElement& lhs, const GFpElement& rhs) //static { - assert(lhs.mp_mod->m_p == rhs.mp_mod->m_p); + assert(lhs.modulus.get_p() == rhs.modulus.get_p()); if(lhs.m_use_montgm && rhs.m_use_montgm) { - assert(rhs.mp_mod->m_p_dash == lhs.mp_mod->m_p_dash); - assert(rhs.mp_mod->m_r == lhs.mp_mod->m_r); - assert(rhs.mp_mod->m_r_inv == lhs.mp_mod->m_r_inv); + assert(rhs.modulus.get_p_dash() == lhs.modulus.get_p_dash()); + assert(rhs.modulus.get_r() == lhs.modulus.get_r()); + assert(rhs.modulus.get_r_inv() == lhs.modulus.get_r_inv()); if(!lhs.m_is_trf && !rhs.m_is_trf) { return false; @@ -327,7 +285,7 @@ bool GFpElement::is_trf_to_mres() const const BigInt& GFpElement::get_p() const { - return (mp_mod->m_p); + return (modulus.get_p()); } const BigInt& GFpElement::get_value() const @@ -345,7 +303,7 @@ const BigInt& GFpElement::get_mres() const if(!m_use_montgm) { // does the following exception really make sense? - // wouldn´t it be better to simply turn on montg.mult. when + // wouldn't it be better to simply turn on montg.mult. when // this explicit request is made? throw Illegal_Transformation("GFpElement is not allowed to be transformed to m-residue"); } @@ -357,107 +315,17 @@ const BigInt& GFpElement::get_mres() const return m_value; } -const GFpElement& GFpElement::operator=(const GFpElement& other) - { - m_value.grow_reg(other.m_value.size()); // grow first for exception safety - - //m_value = other.m_value; - - // m_use_montgm = other.m_use_montgm; - // m_is_trf = other.m_is_trf; - // we want to keep the member pointers, which might be part of a "sharing group" - // but we may not simply overwrite the BigInt values with those of the argument!! - // if ours already contains precomputations, it would be hazardous to - // set them back to zero. - // thus we first check for equality of the moduli, - // then whether either of the two objects already contains - // precomputed values. - - // we also deal with the case were the pointers themsevles are equal: - if(mp_mod.get() == other.mp_mod.get()) - { - // everything ok, we are in the same sharing group anyway, nothing to do - m_value = other.m_value; // cannot throw - m_use_montgm = other.m_use_montgm; - m_is_trf = other.m_is_trf; - return *this; - } - if(mp_mod->m_p != other.mp_mod->m_p) - { - // the moduli are different, this is a special case - // which will not occur in usual applications, - // so we don´t hesitate to simply create new objects - // (we do want to create an independent copy) - mp_mod.reset(new GFpModulus(*other.mp_mod)); // this could throw, - // and because of this - // we haven't modified - // anything so far - m_value = other.m_value; // can't throw - m_use_montgm = other.m_use_montgm; - m_is_trf = other.m_is_trf; - return *this; - } - // exception safety note: from now on we are on the safe - // side with respect to the modulus, - // so we can assign the value now: - m_value = other.m_value; - m_use_montgm = other.m_use_montgm; - m_is_trf = other.m_is_trf; - // the moduli are equal, but we deal with different sharing groups. - // we will NOT fuse the sharing goups - // and we will NOT reset already precomputed values - if(mp_mod->has_precomputations()) - { - // our own sharing group already has precomputed values, - // so nothing to do. - return *this; - } - else - { - // let´s see whether the argument has something for us... - if(other.mp_mod->has_precomputations()) - { - // fetch them for our sharing group - // exc. safety note: grow first - mp_mod->m_p_dash.grow_reg(other.mp_mod->m_p_dash.size()); - mp_mod->m_r.grow_reg(other.mp_mod->m_r.size()); - mp_mod->m_r_inv.grow_reg(other.mp_mod->m_r_inv.size()); - - mp_mod->m_p_dash = other.mp_mod->m_p_dash; - mp_mod->m_r = other.mp_mod->m_r; - mp_mod->m_r_inv = other.mp_mod->m_r_inv; - return *this; - } - } - // our precomputations aren´t set, the arguments neither, - // so we let them alone - return *this; - } - -void GFpElement::share_assign(const GFpElement& other) - { - assert((other.m_is_trf && other.m_use_montgm) || !other.m_is_trf); - - // use grow_to to make it exc safe - m_value.grow_reg(other.m_value.size()); - m_value = other.m_value; - - m_use_montgm = other.m_use_montgm; - m_is_trf = other.m_is_trf; - mp_mod = other.mp_mod; // cannot throw - } - GFpElement& GFpElement::operator+=(const GFpElement& rhs) { GFpElement::align_operands_res(*this, rhs); - workspace = m_value; + BigInt workspace = m_value; workspace += rhs.m_value; - if(workspace >= mp_mod->m_p) - workspace -= mp_mod->m_p; + if(workspace >= modulus.get_p()) + workspace -= modulus.get_p(); m_value = workspace; - assert(m_value < mp_mod->m_p); + assert(m_value < modulus.get_p()); assert(m_value >= 0); return *this; @@ -467,39 +335,39 @@ GFpElement& GFpElement::operator-=(const GFpElement& rhs) { GFpElement::align_operands_res(*this, rhs); - workspace = m_value; + BigInt workspace = m_value; workspace -= rhs.m_value; if(workspace.is_negative()) - workspace += mp_mod->m_p; + workspace += modulus.get_p(); m_value = workspace; - assert(m_value < mp_mod->m_p); + assert(m_value < modulus.get_p()); assert(m_value >= 0); return *this; } GFpElement& GFpElement::operator*= (u32bit rhs) { - workspace = m_value; + BigInt workspace = m_value; workspace *= rhs; - workspace %= mp_mod->m_p; + workspace %= modulus.get_p(); m_value = workspace; return *this; } GFpElement& GFpElement::operator*=(const GFpElement& rhs) { - assert(rhs.mp_mod->m_p == mp_mod->m_p); + assert(rhs.modulus.get_p() == modulus.get_p()); // here, we do not use align_operands_res() for one simple reason: // we want to enforce the transformation to an m-residue, otherwise it would // never happen if(m_use_montgm && rhs.m_use_montgm) { - assert(rhs.mp_mod->m_p == mp_mod->m_p); // is montgm. mult is on, then precomps must be there - assert(rhs.mp_mod->m_p_dash == mp_mod->m_p_dash); - assert(rhs.mp_mod->m_r == mp_mod->m_r); + assert(rhs.modulus.get_p() == modulus.get_p()); // is montgm. mult is on, then precomps must be there + assert(rhs.modulus.get_p_dash() == modulus.get_p_dash()); + assert(rhs.modulus.get_r() == modulus.get_r()); if(!m_is_trf) { trf_to_mres(); @@ -508,8 +376,8 @@ GFpElement& GFpElement::operator*=(const GFpElement& rhs) { rhs.trf_to_mres(); } - workspace = m_value; - montg_mult(m_value, workspace, rhs.m_value, mp_mod->m_p, mp_mod->m_p_dash, mp_mod->m_r); + BigInt workspace = m_value; + montg_mult(m_value, workspace, rhs.m_value, modulus.get_p(), modulus.get_p_dash(), modulus.get_r()); } else // ordinary multiplication { @@ -524,9 +392,9 @@ GFpElement& GFpElement::operator*=(const GFpElement& rhs) rhs.trf_to_ordres(); } - workspace = m_value; + BigInt workspace = m_value; workspace *= rhs.m_value; - workspace %= mp_mod->m_p; + workspace %= modulus.get_p(); m_value = workspace; } return *this; @@ -536,18 +404,17 @@ GFpElement& GFpElement::operator/=(const GFpElement& rhs) { bool use_mres = GFpElement::align_operands_res(*this, rhs); assert((this->m_is_trf && rhs.m_is_trf) || !(this->m_is_trf && rhs.m_is_trf)); - // (internal note: see C86) + if(use_mres) { assert(m_use_montgm && rhs.m_use_montgm); GFpElement rhs_ordres(rhs); rhs_ordres.trf_to_ordres(); rhs_ordres.inverse_in_place(); - workspace = m_value; - workspace *= rhs_ordres.get_value(); - workspace %= mp_mod->m_p; + BigInt workspace = m_value; + workspace *= rhs_ordres.get_value(); + workspace %= modulus.get_p(); m_value = workspace; - } else { @@ -566,30 +433,31 @@ bool GFpElement::is_zero() GFpElement& GFpElement::inverse_in_place() { - m_value = inverse_mod(m_value, mp_mod->m_p); + m_value = inverse_mod(m_value, modulus.get_p()); + if(m_is_trf) { assert(m_use_montgm); - m_value *= mp_mod->m_r; - m_value *= mp_mod->m_r; - m_value %= mp_mod->m_p; + m_value *= modulus.get_r(); + m_value *= modulus.get_r(); + m_value %= modulus.get_p(); } - assert(m_value <= mp_mod->m_p); + assert(m_value <= modulus.get_p()); return *this; } GFpElement& GFpElement::negate() { - m_value = mp_mod->m_p - m_value; - assert(m_value <= mp_mod->m_p); + m_value = modulus.get_p() - m_value; + assert(m_value <= modulus.get_p()); return *this; } void GFpElement::swap(GFpElement& other) { - m_value.swap(other.m_value); - mp_mod.swap(other.mp_mod); + std::swap(m_value, other.m_value); + std::swap(modulus, other.modulus); std::swap<bool>(m_use_montgm,other.m_use_montgm); std::swap<bool>(m_is_trf,other.m_is_trf); } @@ -601,15 +469,9 @@ std::ostream& operator<<(std::ostream& output, const GFpElement& elem) bool operator==(const GFpElement& lhs, const GFpElement& rhs) { - // for effeciency reasons we firstly check whether - //the modulus pointers are different in the first place: - if(lhs.get_ptr_mod() != rhs.get_ptr_mod()) - { - if(lhs.get_p() != rhs.get_p()) - { - return false; - } - } + if(lhs.get_p() != rhs.get_p()) + return false; + // so the modulus is equal, now check the values bool use_mres = GFpElement::align_operands_res(lhs, rhs); |