From 0a927854a10e1e6b9770a81e2e1d9f3093631757 Mon Sep 17 00:00:00 2001 From: Tor Andersson Date: Wed, 19 Jun 2013 15:29:44 +0200 Subject: Rearrange source files. --- source/fitz/crypt-arc4.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 source/fitz/crypt-arc4.c (limited to 'source/fitz/crypt-arc4.c') diff --git a/source/fitz/crypt-arc4.c b/source/fitz/crypt-arc4.c new file mode 100644 index 00000000..9c54fbae --- /dev/null +++ b/source/fitz/crypt-arc4.c @@ -0,0 +1,98 @@ +/* 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 "mupdf/fitz.h" + +void +fz_arc4_init(fz_arc4 *arc4, const 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; + } + } +} + +static unsigned char +fz_arc4_next(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_arc4_encrypt(fz_arc4 *arc4, unsigned char *dest, const unsigned char *src, unsigned len) +{ + unsigned int i; + for (i = 0; i < len; i++) + { + unsigned char x; + x = fz_arc4_next(arc4); + dest[i] = src[i] ^ x; + } +} -- cgit v1.2.3