From 37da2899f40661e3e9631e497da8dc59b971cbd0 Mon Sep 17 00:00:00 2001
From: "Charles.Forsyth" <devnull@localhost>
Date: Fri, 22 Dec 2006 17:07:39 +0000
Subject: 20060303a

---
 libsec/port/rc4.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 libsec/port/rc4.c

(limited to 'libsec/port/rc4.c')

diff --git a/libsec/port/rc4.c b/libsec/port/rc4.c
new file mode 100644
index 00000000..beafa486
--- /dev/null
+++ b/libsec/port/rc4.c
@@ -0,0 +1,104 @@
+#include "os.h"
+#include <libsec.h>
+
+void
+setupRC4state(RC4state *key, uchar *start, int n)
+{
+	int t;
+	int index2;
+	uchar *state;
+	uchar *p, *e, *sp, *se;
+
+	state = key->state;
+	se = &state[256];
+	for(sp = state; sp < se; sp++)
+		*sp = sp - state;
+
+	key->x = 0;
+	key->y = 0;
+	index2 = 0;
+	e = start + n;
+	p = start;
+	for(sp = state; sp < se; sp++)
+	{
+		t = *sp;
+		index2 = (*p + t + index2) & 255;
+		*sp = state[index2];
+		state[index2] = t;
+		if(++p >= e)
+			p = start;
+	}
+}
+
+void
+rc4(RC4state *key, uchar *p, int len)
+{
+	int tx, ty;
+	int x, y;
+	uchar *state;
+	uchar *e;
+
+	x = key->x;
+	y = key->y;
+	state = &key->state[0];
+	for(e = p + len; p < e; p++)
+	{
+		x = (x+1)&255;
+		tx = state[x];
+		y = (y+tx)&255;
+		ty = state[y];
+		state[x] = ty;
+		state[y] = tx;
+		*p ^= state[(tx+ty)&255];
+	}
+	key->x = x;
+	key->y = y;
+}
+
+void
+rc4skip(RC4state *key, int len)
+{
+	int tx, ty;
+	int x, y;
+	uchar *state;
+	int i;
+
+	x = key->x;
+	y = key->y;
+	state = &key->state[0];
+	for(i=0; i<len; i++)
+	{
+		x = (x+1)&255;
+		tx = state[x];
+		y = (y+tx)&255;
+		ty = state[y];
+		state[x] = ty;
+		state[y] = tx;
+	}
+	key->x = x;
+	key->y = y;
+}
+
+void
+rc4back(RC4state *key, int len)
+{
+	int tx, ty;
+	int x, y;
+	uchar *state;
+	int i;
+
+	x = key->x;
+	y = key->y;
+	state = &key->state[0];
+	for(i=0; i<len; i++)
+	{
+		ty = state[x];
+		tx = state[y];
+		state[y] = ty;
+		state[x] = tx;
+		y = (y-tx)&255;
+		x = (x-1)&255;
+	}
+	key->x = x;
+	key->y = y;
+}
-- 
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