diff options
author | lloyd <[email protected]> | 2006-05-18 18:33:19 +0000 |
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committer | lloyd <[email protected]> | 2006-05-18 18:33:19 +0000 |
commit | a2c99d3270eb73ef2db5704fc54356c6b75096f8 (patch) | |
tree | ad3d6c4fcc8dd0f403f8105598943616246fe172 /src/mp_numth.cpp |
Initial checkin1.5.6
Diffstat (limited to 'src/mp_numth.cpp')
-rw-r--r-- | src/mp_numth.cpp | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/src/mp_numth.cpp b/src/mp_numth.cpp new file mode 100644 index 000000000..8ad7a37e9 --- /dev/null +++ b/src/mp_numth.cpp @@ -0,0 +1,69 @@ +/************************************************* +* Fused and Important MP Algorithms Source File * +* (C) 1999-2006 The Botan Project * +*************************************************/ + +#include <botan/numthry.h> +#include <botan/mp_core.h> +#include <botan/util.h> +#include <algorithm> + +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<word> 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<word> 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; + } + +} |