1 files changed, 224 insertions, 0 deletions
diff --git a/botan/src/math/bigint/big_ops2.cpp b/botan/src/math/bigint/big_ops2.cpp
new file mode 100644
index 0000000..488eca9
--- /dev/null
+++ b/botan/src/math/bigint/big_ops2.cpp
@@ -0,0 +1,224 @@
+/*
+* BigInt Assignment Operators
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/bigint.h>
+#include <botan/mp_core.h>
+#include <botan/bit_ops.h>
+#include <algorithm>
+
+namespace Botan {
+
+/*
+* Addition Operator
+*/
+BigInt& BigInt::operator+=(const BigInt& y)
+   {
+   const u32bit x_sw = sig_words(), y_sw = y.sig_words();
+
+   const u32bit reg_size = std::max(x_sw, y_sw) + 1;
+   grow_to(reg_size);
+
+   if(sign() == y.sign())
+      bigint_add2(get_reg(), reg_size - 1, y.data(), y_sw);
+   else
+      {
+      s32bit relative_size = bigint_cmp(data(), x_sw, y.data(), y_sw);
+
+      if(relative_size < 0)
+         {
+         SecureVector<word> z(reg_size - 1);
+         bigint_sub3(z, y.data(), reg_size - 1, data(), x_sw);
+         copy_mem(get_reg().begin(), z.begin(), z.size());
+         set_sign(y.sign());
+         }
+      else if(relative_size == 0)
+         {
+         get_reg().clear();
+         set_sign(Positive);
+         }
+      else if(relative_size > 0)
+         bigint_sub2(get_reg(), x_sw, y.data(), y_sw);
+      }
+
+   return (*this);
+   }
+
+/*
+* Subtraction Operator
+*/
+BigInt& BigInt::operator-=(const BigInt& y)
+   {
+   const u32bit x_sw = sig_words(), y_sw = y.sig_words();
+
+   s32bit relative_size = bigint_cmp(data(), x_sw, y.data(), y_sw);
+
+   const u32bit reg_size = std::max(x_sw, y_sw) + 1;
+   grow_to(reg_size);
+
+   if(relative_size < 0)
+      {
+      if(sign() == y.sign())
+         {
+         SecureVector<word> z(reg_size - 1);
+         bigint_sub3(z, y.data(), reg_size - 1, data(), x_sw);
+         copy_mem(get_reg().begin(), z.begin(), z.size());
+         }
+      else
+         bigint_add2(get_reg(), reg_size - 1, y.data(), y_sw);
+
+      set_sign(y.reverse_sign());
+      }
+   else if(relative_size == 0)
+      {
+      if(sign() == y.sign())
+         {
+         get_reg().clear();
+         set_sign(Positive);
+         }
+      else
+         bigint_shl1(get_reg(), x_sw, 0, 1);
+      }
+   else if(relative_size > 0)
+      {
+      if(sign() == y.sign())
+         bigint_sub2(get_reg(), x_sw, y.data(), y_sw);
+      else
+         bigint_add2(get_reg(), reg_size - 1, y.data(), y_sw);
+      }
+
+   return (*this);
+   }
+
+/*
+* Multiplication Operator
+*/
+BigInt& BigInt::operator*=(const BigInt& y)
+   {
+   const u32bit x_sw = sig_words(), y_sw = y.sig_words();
+   set_sign((sign() == y.sign()) ? Positive : Negative);
+
+   if(x_sw == 0 || y_sw == 0)
+      {
+      get_reg().clear();
+      set_sign(Positive);
+      }
+   else if(x_sw == 1 && y_sw)
+      {
+      grow_to(y_sw + 2);
+      bigint_linmul3(get_reg(), y.data(), y_sw, word_at(0));
+      }
+   else if(y_sw == 1 && x_sw)
+      {
+      grow_to(x_sw + 2);
+      bigint_linmul2(get_reg(), x_sw, y.word_at(0));
+      }
+   else
+      {
+      grow_to(size() + y.size());
+
+      SecureVector<word> z(data(), x_sw);
+      SecureVector<word> workspace(size());
+
+      bigint_mul(get_reg(), size(), workspace,
+                 z, z.size(), x_sw,
+                 y.data(), y.size(), y_sw);
+      }
+
+   return (*this);
+   }
+
+/*
+* Division Operator
+*/
+BigInt& BigInt::operator/=(const BigInt& y)
+   {
+   if(y.sig_words() == 1 && power_of_2(y.word_at(0)))
+      (*this) >>= (y.bits() - 1);
+   else
+      (*this) = (*this) / y;
+   return (*this);
+   }
+
+/*
+* Modulo Operator
+*/
+BigInt& BigInt::operator%=(const BigInt& mod)
+   {
+   return (*this = (*this) % mod);
+   }
+
+/*
+* Modulo Operator
+*/
+word BigInt::operator%=(word mod)
+   {
+   if(mod == 0)
+      throw BigInt::DivideByZero();
+   if(power_of_2(mod))
+       {
+       word result = (word_at(0) & (mod - 1));
+       clear();
+       grow_to(2);
+       get_reg()[0] = result;
+       return result;
+       }
+
+   word remainder = 0;
+
+   for(u32bit j = sig_words(); j > 0; --j)
+      remainder = bigint_modop(remainder, word_at(j-1), mod);
+   clear();
+   grow_to(2);
+
+   if(remainder && sign() == BigInt::Negative)
+      get_reg()[0] = mod - remainder;
+   else
+      get_reg()[0] = remainder;
+
+   set_sign(BigInt::Positive);
+
+   return word_at(0);
+   }
+
+/*
+* Left Shift Operator
+*/
+BigInt& BigInt::operator<<=(u32bit shift)
+   {
+   if(shift)
+      {
+      const u32bit shift_words = shift / MP_WORD_BITS,
+                   shift_bits  = shift % MP_WORD_BITS,
+                   words = sig_words();
+
+      grow_to(words + shift_words + (shift_bits ? 1 : 0));
+      bigint_shl1(get_reg(), words, shift_words, shift_bits);
+      }
+
+   return (*this);
+   }
+
+/*
+* Right Shift Operator
+*/
+BigInt& BigInt::operator>>=(u32bit shift)
+   {
+   if(shift)
+      {
+      const u32bit shift_words = shift / MP_WORD_BITS,
+                   shift_bits  = shift % MP_WORD_BITS;
+
+      bigint_shr1(get_reg(), sig_words(), shift_words, shift_bits);
+
+      if(is_zero())
+         set_sign(Positive);
+      }
+
+   return (*this);
+   }
+
+}