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authorlloyd <[email protected]>2008-09-30 22:41:49 +0000
committerlloyd <[email protected]>2008-09-30 22:41:49 +0000
commit13d08cbe978c4cd0de01aa0120c39470508cbbcb (patch)
treeff93739131cbca0dbdf23a31cd4b7611faf5aa6e /src/math/numbertheory/mp_numth.cpp
parent8854fe339f2e1f81091ba65c042824e8cc62cbbc (diff)
Rearrange BigInt directories:
math/bigint - BigInt implementation math/numbertheory - Math stuff built on top of BigInt Coming soon: math/gfp (parts of pk/ecdsa) Update deps in the pk files
Diffstat (limited to 'src/math/numbertheory/mp_numth.cpp')
-rw-r--r--src/math/numbertheory/mp_numth.cpp69
1 files changed, 69 insertions, 0 deletions
diff --git a/src/math/numbertheory/mp_numth.cpp b/src/math/numbertheory/mp_numth.cpp
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+++ b/src/math/numbertheory/mp_numth.cpp
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+/*************************************************
+* Fused and Important MP Algorithms Source File *
+* (C) 1999-2007 Jack Lloyd *
+*************************************************/
+
+#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;
+ }
+
+}