Use 64-bit multiply for Rabbit

1 files changed, 8 insertions, 0 deletions

diff --git a/rabbit.cpp b/rabbit.cpp
index 2c32f4f0..8bc4a499 100644
--- a/rabbit.cpp
+++ b/rabbit.cpp
@@ -15,10 +15,12 @@
 ANONYMOUS_NAMESPACE_BEGIN

 

 using CryptoPP::word32;

+using CryptoPP::word64;

 using CryptoPP::rotlConstant;

 

 word32 G_func(word32 x)

 {

+#if 0

 	/* Temporary variables */

 	word32 a, b, h, l;

 

@@ -32,6 +34,12 @@ word32 G_func(word32 x)
 

 	/* Return high XOR low */

 	return static_cast<word32>(h^l);

+#endif

+

+	// Thanks to Jack Lloyd for suggesting the 64-bit multiply.

+	word64 z = x;

+	z *= x;

+	return static_cast<word32>((z >> 32) ^ z);

 }

 

 word32 NextState(word32 c[8], word32 x[8], word32 carry)