From ee154f16bd09a43359967f7e7b86c3677c09461d Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor@ghostscript.com>
Date: Wed, 30 Mar 2005 08:30:22 +0200
Subject: rename part 1 -- files
---
stream/crypt_arc4.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 95 insertions(+)
create mode 100644 stream/crypt_arc4.c
(limited to 'stream/crypt_arc4.c')
diff --git a/stream/crypt_arc4.c b/stream/crypt_arc4.c
new file mode 100644
index 00000000..86c9afd8
--- /dev/null
+++ b/stream/crypt_arc4.c
@@ -0,0 +1,95 @@
+/* This code illustrates a sample implementation
+ * of the Arcfour algorithm
+ * Copyright (c) April 29, 1997 Kalle Kaukonen.
+ * All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that this copyright
+ * notice and disclaimer are retained.
+ *
+ * THIS SOFTWARE IS PROVIDED BY KALLE KAUKONEN AND CONTRIBUTORS ``AS
+ * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KALLE
+ * KAUKONEN OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <fitz.h>
+
+void
+fz_arc4init(fz_arc4 *arc4, unsigned char *key, unsigned keylen)
+{
+ unsigned int t, u;
+ unsigned int keyindex;
+ unsigned int stateindex;
+ unsigned char *state;
+ unsigned int counter;
+
+ state = arc4->state;
+
+ arc4->x = 0;
+ arc4->y = 0;
+
+ for (counter = 0; counter < 256; counter++) {
+ state[counter] = counter;
+ }
+
+ keyindex = 0;
+ stateindex = 0;
+
+ for (counter = 0; counter < 256; counter++) {
+ t = state[counter];
+ stateindex = (stateindex + key[keyindex] + t) & 0xff;
+ u = state[stateindex];
+
+ state[stateindex] = t;
+ state[counter] = u;
+
+ if (++keyindex >= keylen) {
+ keyindex = 0;
+ }
+ }
+}
+
+unsigned char
+fz_arc4next(fz_arc4 *arc4)
+{
+ unsigned int x;
+ unsigned int y;
+ unsigned int sx, sy;
+ unsigned char *state;
+
+ state = arc4->state;
+
+ x = (arc4->x + 1) & 0xff;
+ sx = state[x];
+ y = (sx + arc4->y) & 0xff;
+ sy = state[y];
+
+ arc4->x = x;
+ arc4->y = y;
+
+ state[y] = sx;
+ state[x] = sy;
+
+ return state[(sx + sy) & 0xff];
+}
+
+void
+fz_arc4encrypt(fz_arc4 *arc4, unsigned char *dest, unsigned char *src, unsigned len)
+{
+ unsigned int i;
+ for (i = 0; i < len; i++) {
+ unsigned char x;
+ x = fz_arc4next(arc4);
+ dest[i] = src[i] ^ x;
+ }
+}
+
--
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