/************************************************* * Fused and Important MP Algorithms Source File * * (C) 1999-2007 The Botan Project * *************************************************/ #include #include #include #include namespace Botan { /************************************************* * Square a BigInt * *************************************************/ BigInt square(const BigInt& x) { const u32bit x_sw = x.sig_words(); BigInt z(BigInt::Positive, round_up(2*x_sw, 16)); SecureVector workspace(z.size()); bigint_sqr(z.get_reg(), z.size(), workspace, x.data(), x.size(), x_sw); return z; } /************************************************* * Multiply-Add Operation * *************************************************/ BigInt mul_add(const BigInt& a, const BigInt& b, const BigInt& c) { if(c.is_negative() || c.is_zero()) throw Invalid_Argument("mul_add: Third argument must be > 0"); BigInt::Sign sign = BigInt::Positive; if(a.sign() != b.sign()) sign = BigInt::Negative; const u32bit a_sw = a.sig_words(); const u32bit b_sw = b.sig_words(); const u32bit c_sw = c.sig_words(); BigInt r(sign, std::max(a.size() + b.size(), c_sw) + 1); SecureVector workspace(r.size()); bigint_mul(r.get_reg(), r.size(), workspace, a.data(), a.size(), a_sw, b.data(), b.size(), b_sw); const u32bit r_size = std::max(r.sig_words(), c_sw); bigint_add2(r.get_reg(), r_size, c.data(), c_sw); return r; } /************************************************* * Subtract-Multiply Operation * *************************************************/ BigInt sub_mul(const BigInt& a, const BigInt& b, const BigInt& c) { if(a.is_negative() || b.is_negative()) throw Invalid_Argument("sub_mul: First two arguments must be >= 0"); BigInt r = a; r -= b; r *= c; return r; } }