From 0380a6c281646e73f28976290dbf0da767cfd97c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=B6ller?= <nisse@lysator.liu.se>
Date: Thu, 5 Feb 2004 16:08:20 +0100
Subject: [PATCH] =?UTF-8?q?(arcfour=5Fcrypt):=20Optimization=20suggested?=
=?UTF-8?q?=20by=20Jonas=20Walld=C3=A9n.=20Makes=20arcfour=20up=20to=2050%?=
=?UTF-8?q?=20faster=20on=20x86=20and=20ppc,=20and=20probably=20on=20other?=
=?UTF-8?q?=20architectures=20as=20well.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Rev: src/nettle/arcfour.c:1.4
---
arcfour.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/arcfour.c b/arcfour.c
index 03c9cd88..d5424348 100644
--- a/arcfour.c
+++ b/arcfour.c
@@ -63,14 +63,16 @@ arcfour_crypt(struct arcfour_ctx *ctx,
const uint8_t *src)
{
register uint8_t i, j;
+ register int si, sj;
i = ctx->i; j = ctx->j;
while(length--)
{
i++; i &= 0xff;
- j += ctx->S[i]; j &= 0xff;
- SWAP(ctx->S[i], ctx->S[j]);
- *dst++ = *src++ ^ ctx->S[ (ctx->S[i] + ctx->S[j]) & 0xff ];
+ si = ctx->S[i];
+ j += si; j &= 0xff;
+ sj = ctx->S[i] = ctx->S[j];
+ *dst++ = *src++ ^ ctx->S[ (si + sj) & 0xff ];
}
ctx->i = i; ctx->j = j;
}
@@ -80,14 +82,16 @@ arcfour_stream(struct arcfour_ctx *ctx,
unsigned length, uint8_t *dst)
{
register uint8_t i, j;
+ register int si, sj;
i = ctx->i; j = ctx->j;
while(length--)
{
i++; i &= 0xff;
- j += ctx->S[i]; j &= 0xff;
- SWAP(ctx->S[i], ctx->S[j]);
- *dst++ = ctx->S[ (ctx->S[i] + ctx->S[j]) & 0xff ];
+ si = ctx->S[i];
+ j += si; j &= 0xff;
+ sj = ctx->S[i] = ctx->S[j];
+ *dst++ = ctx->S[ (si + sj) & 0xff ];
}
ctx->i = i; ctx->j = j;
}
--
GitLab