Make IDEA::mul_inv just a function in an anonymous namespace, since it really

had no reason/need to be a class method.

1 files changed, 36 insertions, 38 deletions

diff --git a/src/idea.cpp b/src/idea.cpp
index f37d51d0e..e2338fa0d 100644
--- a/src/idea.cpp
+++ b/src/idea.cpp
@@ -13,17 +13,44 @@ namespace {
 /*************************************************
 * Multiplication modulo 65537                    *
 *************************************************/
-inline u16bit mul(u16bit a, u16bit b)
+inline u16bit mul(u16bit x, u16bit y)
    {
-   if(a && b)
+   if(x && y)
       {
-      u32bit temp = static_cast<u32bit>(a) * b;
-      a = static_cast<u16bit>(temp >> 16);
-      b = static_cast<u16bit>(temp & 0xFFFF);
-      return static_cast<u16bit>(b - a + ((b < a) ? 1 : 0));
+      u32bit T = static_cast<u32bit>(x) * y;
+      x = static_cast<u16bit>(T >> 16);
+      y = static_cast<u16bit>(T & 0xFFFF);
+      return static_cast<u16bit>(y - x + ((y < x) ? 1 : 0));
       }
    else
-      return static_cast<u16bit>(1 - a - b);
+      return static_cast<u16bit>(1 - x - y);
+   }
+
+/*************************************************
+* Find multiplicative inverses modulo 65537      *
+*************************************************/
+u16bit mul_inv(u16bit x)
+   {
+   if(x <= 1)
+      return x;
+
+   u16bit t0 = static_cast<u16bit>(65537 / x), t1 = 1;
+   u16bit y = static_cast<u16bit>(65537 % x);
+
+   while(y != 1)
+      {
+      u16bit q = x / y;
+      x %= y;
+      t1 += q * t0;
+
+      if(x == 1)
+         return t1;
+
+      q = y / x;
+      y %= x;
+      t0 += q * t1;
+      }
+   return (1 - t0);
    }
 
 }
@@ -46,8 +73,7 @@ void IDEA::enc(const byte in[], byte out[]) const
       X4 = mul(X4, EK[6*j+3]);
 
       u16bit T0 = X3;
-      X3 ^= X1;
-      X3 = mul(X3, EK[6*j+4]);
+      X3 = mul(X3 ^ X1, EK[6*j+4]);
 
       u16bit T1 = X2;
       X2 = mul((X2 ^ X4) + X3, EK[6*j+5]);
@@ -85,8 +111,7 @@ void IDEA::dec(const byte in[], byte out[]) const
       X4 = mul(X4, DK[6*j+3]);
 
       u16bit T0 = X3;
-      X3 ^= X1;
-      X3 = mul(X3, DK[6*j+4]);
+      X3 = mul(X3 ^ X1, DK[6*j+4]);
 
       u16bit T1 = X2;
       X2 = mul((X2 ^ X4) + X3, DK[6*j+5]);
@@ -107,33 +132,6 @@ void IDEA::dec(const byte in[], byte out[]) const
    }
 
 /*************************************************
-* Find multiplicative inverses modulo 65537      *
-*************************************************/
-u16bit IDEA::mul_inv(u16bit x)
-   {
-   if(x <= 1)
-      return x;
-
-   u16bit t0 = static_cast<u16bit>(65537 / x), t1 = 1;
-   u16bit y = static_cast<u16bit>(65537 % x);
-
-   while(y != 1)
-      {
-      u16bit q = x / y;
-      x %= y;
-      t1 += q * t0;
-
-      if(x == 1)
-         return t1;
-
-      q = y / x;
-      y %= x;
-      t0 += q * t1;
-      }
-   return (1 - t0);
-   }
-
-/*************************************************
 * IDEA Key Schedule                              *
 *************************************************/
 void IDEA::key(const byte key[], u32bit)