Consolidate code for choosing a window size for fixed width window

exponentiation algorithms.

1 files changed, 1 insertions, 33 deletions

diff --git a/src/math/numbertheory/powm_mnt.cpp b/src/math/numbertheory/powm_mnt.cpp
index 2d18ccdef..cce142020 100644
--- a/src/math/numbertheory/powm_mnt.cpp
+++ b/src/math/numbertheory/powm_mnt.cpp
@@ -14,38 +14,6 @@ namespace Botan {
 namespace {
 
 /*
-* Try to choose a good window size
-*/
-u32bit montgomery_powm_window_bits(u32bit exp_bits, u32bit,
-                                   Power_Mod::Usage_Hints hints)
-   {
-   static const u32bit wsize[][2] = {
-      { 2048, 4 }, { 1024, 3 }, { 256, 2 }, { 128, 1 }, { 0, 0 }
-   };
-
-   u32bit window_bits = 1;
-
-   if(exp_bits)
-      {
-      for(u32bit j = 0; wsize[j][0]; ++j)
-         {
-         if(exp_bits >= wsize[j][0])
-            {
-            window_bits += wsize[j][1];
-            break;
-            }
-         }
-      }
-
-   if(hints & Power_Mod::BASE_IS_FIXED)
-      window_bits += 2;
-   if(hints & Power_Mod::EXP_IS_LARGE)
-      ++window_bits;
-
-   return window_bits;
-   }
-
-/*
 * Montgomery Reduction
 */
 inline void montgomery_reduce(BigInt& out, MemoryRegion<word>& z_buf,
@@ -76,7 +44,7 @@ void Montgomery_Exponentiator::set_exponent(const BigInt& exp)
 */
 void Montgomery_Exponentiator::set_base(const BigInt& base)
    {
-   window_bits = montgomery_powm_window_bits(exp.bits(), base.bits(), hints);
+   window_bits = Power_Mod::window_bits(exp.bits(), base.bits(), hints);
 
    g.resize((1 << window_bits) - 1);