1 files changed, 65 insertions, 0 deletions
diff --git a/src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp b/src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp
new file mode 100644
index 0000000000..85a0364b5a
--- /dev/null
+++ b/src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp
@@ -0,0 +1,65 @@
+/*
+* Fixed Window Exponentiation
+* (C) 1999-2007 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/internal/def_powm.h>
+#include <vector>
+
+namespace Botan {
+
+/*
+* Set the exponent
+*/
+void Fixed_Window_Exponentiator::set_exponent(const BigInt& e)
+   {
+   m_exp = e;
+   }
+
+/*
+* Set the base
+*/
+void Fixed_Window_Exponentiator::set_base(const BigInt& base)
+   {
+   m_window_bits = Power_Mod::window_bits(m_exp.bits(), base.bits(), m_hints);
+
+   m_g.resize(1U << m_window_bits);
+   m_g[0] = 1;
+   m_g[1] = base;
+
+   for(size_t i = 2; i != m_g.size(); ++i)
+      m_g[i] = m_reducer.multiply(m_g[i-1], m_g[1]);
+   }
+
+/*
+* Compute the result
+*/
+BigInt Fixed_Window_Exponentiator::execute() const
+   {
+   const size_t exp_nibbles = (m_exp.bits() + m_window_bits - 1) / m_window_bits;
+
+   BigInt x = 1;
+
+   for(size_t i = exp_nibbles; i > 0; --i)
+      {
+      for(size_t j = 0; j != m_window_bits; ++j)
+         x = m_reducer.square(x);
+
+      const uint32_t nibble = m_exp.get_substring(m_window_bits*(i-1), m_window_bits);
+
+      x = m_reducer.multiply(x, m_g[nibble]);
+      }
+   return x;
+   }
+
+/*
+* Fixed_Window_Exponentiator Constructor
+*/
+Fixed_Window_Exponentiator::Fixed_Window_Exponentiator(const BigInt& n,
+                                                       Power_Mod::Usage_Hints hints)
+      : m_reducer{Modular_Reducer(n)}, m_exp{}, m_window_bits{}, m_g{}, m_hints{hints}
+   {}
+
+}