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authorlloyd <lloyd@randombit.net>2010-03-03 02:28:45 +0000
committerlloyd <lloyd@randombit.net>2010-03-03 02:28:45 +0000
commit04a40219dfc444184ff5650a89e740e90b0dfb4d (patch)
tree60aa127645e6d29273b8edcb74944ec0fece5a1b
parent82ab6d27cc2b434b4b7ffa528396d67fe6993222 (diff)
Use a macro to make Salsa20 code a bit more compact
-rw-r--r--src/stream/salsa20/salsa20.cpp92
1 files changed, 26 insertions, 66 deletions
diff --git a/src/stream/salsa20/salsa20.cpp b/src/stream/salsa20/salsa20.cpp
index 0243149f1..7238bdcb8 100644
--- a/src/stream/salsa20/salsa20.cpp
+++ b/src/stream/salsa20/salsa20.cpp
@@ -14,6 +14,14 @@ namespace Botan {
namespace {
+#define SALSA20_QUARTER_ROUND(x1, x2, x3, x4) \
+ do { \
+ x2 ^= rotate_left(x1 + x4, 7); \
+ x3 ^= rotate_left(x2 + x1, 9); \
+ x4 ^= rotate_left(x3 + x2, 13); \
+ x1 ^= rotate_left(x4 + x3, 18); \
+ } while(0)
+
/*
* Generate HSalsa20 cipher stream (for XSalsa20 IV setup)
*/
@@ -38,39 +46,15 @@ void hsalsa20(u32bit output[8], const u32bit input[16])
for(u32bit i = 0; i != 10; ++i)
{
- x04 ^= rotate_left(x00 + x12, 7);
- x08 ^= rotate_left(x04 + x00, 9);
- x12 ^= rotate_left(x08 + x04, 13);
- x00 ^= rotate_left(x12 + x08, 18);
- x09 ^= rotate_left(x05 + x01, 7);
- x13 ^= rotate_left(x09 + x05, 9);
- x01 ^= rotate_left(x13 + x09, 13);
- x05 ^= rotate_left(x01 + x13, 18);
- x14 ^= rotate_left(x10 + x06, 7);
- x02 ^= rotate_left(x14 + x10, 9);
- x06 ^= rotate_left(x02 + x14, 13);
- x10 ^= rotate_left(x06 + x02, 18);
- x03 ^= rotate_left(x15 + x11, 7);
- x07 ^= rotate_left(x03 + x15, 9);
- x11 ^= rotate_left(x07 + x03, 13);
- x15 ^= rotate_left(x11 + x07, 18);
-
- x01 ^= rotate_left(x00 + x03, 7);
- x02 ^= rotate_left(x01 + x00, 9);
- x03 ^= rotate_left(x02 + x01, 13);
- x00 ^= rotate_left(x03 + x02, 18);
- x06 ^= rotate_left(x05 + x04, 7);
- x07 ^= rotate_left(x06 + x05, 9);
- x04 ^= rotate_left(x07 + x06, 13);
- x05 ^= rotate_left(x04 + x07, 18);
- x11 ^= rotate_left(x10 + x09, 7);
- x08 ^= rotate_left(x11 + x10, 9);
- x09 ^= rotate_left(x08 + x11, 13);
- x10 ^= rotate_left(x09 + x08, 18);
- x12 ^= rotate_left(x15 + x14, 7);
- x13 ^= rotate_left(x12 + x15, 9);
- x14 ^= rotate_left(x13 + x12, 13);
- x15 ^= rotate_left(x14 + x13, 18);
+ SALSA20_QUARTER_ROUND(x00, x04, x08, x12);
+ SALSA20_QUARTER_ROUND(x05, x09, x13, x01);
+ SALSA20_QUARTER_ROUND(x10, x14, x02, x06);
+ SALSA20_QUARTER_ROUND(x15, x03, x07, x11);
+
+ SALSA20_QUARTER_ROUND(x00, x01, x02, x03);
+ SALSA20_QUARTER_ROUND(x05, x06, x07, x04);
+ SALSA20_QUARTER_ROUND(x10, x11, x08, x09);
+ SALSA20_QUARTER_ROUND(x15, x12, x13, x14);
}
output[0] = x00;
@@ -107,39 +91,15 @@ void salsa20(byte output[64], const u32bit input[16])
for(u32bit i = 0; i != 10; ++i)
{
- x04 ^= rotate_left(x00 + x12, 7);
- x08 ^= rotate_left(x04 + x00, 9);
- x12 ^= rotate_left(x08 + x04, 13);
- x00 ^= rotate_left(x12 + x08, 18);
- x09 ^= rotate_left(x05 + x01, 7);
- x13 ^= rotate_left(x09 + x05, 9);
- x01 ^= rotate_left(x13 + x09, 13);
- x05 ^= rotate_left(x01 + x13, 18);
- x14 ^= rotate_left(x10 + x06, 7);
- x02 ^= rotate_left(x14 + x10, 9);
- x06 ^= rotate_left(x02 + x14, 13);
- x10 ^= rotate_left(x06 + x02, 18);
- x03 ^= rotate_left(x15 + x11, 7);
- x07 ^= rotate_left(x03 + x15, 9);
- x11 ^= rotate_left(x07 + x03, 13);
- x15 ^= rotate_left(x11 + x07, 18);
-
- x01 ^= rotate_left(x00 + x03, 7);
- x02 ^= rotate_left(x01 + x00, 9);
- x03 ^= rotate_left(x02 + x01, 13);
- x00 ^= rotate_left(x03 + x02, 18);
- x06 ^= rotate_left(x05 + x04, 7);
- x07 ^= rotate_left(x06 + x05, 9);
- x04 ^= rotate_left(x07 + x06, 13);
- x05 ^= rotate_left(x04 + x07, 18);
- x11 ^= rotate_left(x10 + x09, 7);
- x08 ^= rotate_left(x11 + x10, 9);
- x09 ^= rotate_left(x08 + x11, 13);
- x10 ^= rotate_left(x09 + x08, 18);
- x12 ^= rotate_left(x15 + x14, 7);
- x13 ^= rotate_left(x12 + x15, 9);
- x14 ^= rotate_left(x13 + x12, 13);
- x15 ^= rotate_left(x14 + x13, 18);
+ SALSA20_QUARTER_ROUND(x00, x04, x08, x12);
+ SALSA20_QUARTER_ROUND(x05, x09, x13, x01);
+ SALSA20_QUARTER_ROUND(x10, x14, x02, x06);
+ SALSA20_QUARTER_ROUND(x15, x03, x07, x11);
+
+ SALSA20_QUARTER_ROUND(x00, x01, x02, x03);
+ SALSA20_QUARTER_ROUND(x05, x06, x07, x04);
+ SALSA20_QUARTER_ROUND(x10, x11, x08, x09);
+ SALSA20_QUARTER_ROUND(x15, x12, x13, x14);
}
store_le(x00 + input[ 0], output + 4 * 0);