diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/math/gfpmath/gfp_element.cpp | 47 | ||||
| -rw-r--r-- | src/math/gfpmath/gfp_element.h | 6 |
2 files changed, 25 insertions, 28 deletions
diff --git a/src/math/gfpmath/gfp_element.cpp b/src/math/gfpmath/gfp_element.cpp index 47b5429b3..f5ef28a00 100644 --- a/src/math/gfpmath/gfp_element.cpp +++ b/src/math/gfpmath/gfp_element.cpp @@ -1,14 +1,13 @@ /****************************************************** -* Arithmetic for prime fields GF(p) * -* * -* (C) 2007 Martin Doering * -* [email protected] * -* Christoph Ludwig * -* [email protected] * -* Falko Strenzke * -* [email protected] * -* 2008 Jack Lloyd * -******************************************************/ + * Arithmetic for prime fields GF(p) (source file) * + * * + * (C) 2007 Martin Doering * + * [email protected] * + * Christoph Ludwig * + * [email protected] * + * Falko Strenzke * + * [email protected] * + ******************************************************/ #include <botan/gfp_element.h> #include <botan/numthry.h> @@ -22,7 +21,7 @@ namespace Botan { namespace { -void inner_montg_mult_sos(word result[], const word* a_bar, const word* b_bar, const word* n, const word n_dash, u32bit s) +void inner_montg_mult_sos(word result[], const word* a_bar, const word* b_bar, const word* n, const word* n_dash, u32bit s) { SecureVector<word> t; t.grow_to(2*s+1); @@ -34,6 +33,10 @@ void inner_montg_mult_sos(word result[], const word* a_bar, const word* b_bar, c word S = 0; for (u32bit j=0; j<s; j++) { + // we use: + // word word_madd3(word a, word b, word c, word d, word* carry) + // returns a * b + c + d and resets the carry (not using it as input) + S = word_madd3(a_bar[j], b_bar[i], t[i+j], &C); t[i+j] = S; } @@ -48,7 +51,7 @@ void inner_montg_mult_sos(word result[], const word* a_bar, const word* b_bar, c word C = 0; word zero = 0; - word m = word_madd2(t[i], n_dash, &zero); + word m = word_madd2(t[i], n_dash[0], &zero); for (u32bit j=0; j<s; j++) { @@ -117,14 +120,8 @@ void montg_mult(BigInt& result, BigInt& a_bar, BigInt& b_bar, const BigInt& m, c b_bar.grow_to(s); result.grow_to(s); - inner_montg_mult_sos(result.get_reg(), a_bar.data(), b_bar.data(), m.data(), m_dash.data()[0], s); - /* - std::cout << "result = " << result << "\n" - << "a_bar = " << a_bar << "\n" - << "b_bar = " << b_bar << "\n" - << "m = " << m << "\n" - << "m_dash = " << m_dash.data()[0] << "\n"; - */ + inner_montg_mult_sos(result.get_reg(), a_bar.data(), b_bar.data(), + m.data(), m_dash.data(), s); } /** @@ -133,8 +130,6 @@ void montg_mult(BigInt& result, BigInt& a_bar, BigInt& b_bar, const BigInt& m, c */ BigInt montgm_calc_r_oddmod(const BigInt& prime) { - assert(prime.is_odd()); - u32bit n = prime.sig_words(); BigInt result(1); result <<= n*BOTAN_MP_WORD_BITS; @@ -196,6 +191,7 @@ 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); @@ -245,6 +241,7 @@ void GFpElement::ensure_montgm_precomp() const assert(!mp_mod->m_r_inv.is_zero()); assert(!mp_mod->m_p_dash.is_zero()); } + } void GFpElement::set_shrd_mod(std::tr1::shared_ptr<GFpModulus> const p_mod) @@ -482,7 +479,7 @@ GFpElement& GFpElement::operator-=(const GFpElement& rhs) return *this; } -GFpElement& GFpElement::operator*= (u64bit rhs) +GFpElement& GFpElement::operator*= (u32bit rhs) { workspace = m_value; workspace *= rhs; @@ -661,14 +658,14 @@ GFpElement operator*(const GFpElement& lhs, const GFpElement& rhs) return result; } -GFpElement operator*(const GFpElement& lhs, u64bit rhs) +GFpElement operator*(const GFpElement& lhs, u32bit rhs) { GFpElement result(lhs); result *= rhs; return result; } -GFpElement operator*(u64bit lhs, const GFpElement& rhs) +GFpElement operator*(u32bit lhs, const GFpElement& rhs) { return rhs*lhs; } diff --git a/src/math/gfpmath/gfp_element.h b/src/math/gfpmath/gfp_element.h index 067825bc3..39e728cfa 100644 --- a/src/math/gfpmath/gfp_element.h +++ b/src/math/gfpmath/gfp_element.h @@ -142,7 +142,7 @@ class BOTAN_DLL GFpElement * @param rhs the value to multiply with the local value * @result *this */ - GFpElement& operator*= (u64bit rhs); + GFpElement& operator*= (u32bit rhs); /** * Negate internal value(*this *= -1 ) @@ -270,8 +270,8 @@ GFpElement operator-(const GFpElement& lhs); GFpElement operator*(const GFpElement& lhs, const GFpElement& rhs); GFpElement operator/(const GFpElement& lhs, const GFpElement& rhs); -GFpElement operator* (const GFpElement& lhs, u64bit rhs); -GFpElement operator* (u64bit rhs, const GFpElement& lhs); +GFpElement operator* (const GFpElement& lhs, u32bit rhs); +GFpElement operator* (u32bit rhs, const GFpElement& lhs); // io operators std::ostream& operator<<(std::ostream& output, const GFpElement& elem); |