From 094535c010320967639e8e86f974d878e80baa72 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Fri, 1 May 2015 16:13:57 +0200 Subject: Imported Upstream version 1.7.0 --- ccast/axTLS/rc4.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 ccast/axTLS/rc4.c (limited to 'ccast/axTLS/rc4.c') diff --git a/ccast/axTLS/rc4.c b/ccast/axTLS/rc4.c new file mode 100644 index 0000000..12a1211 --- /dev/null +++ b/ccast/axTLS/rc4.c @@ -0,0 +1,92 @@ +/* + * Copyright (c) 2007, Cameron Rich + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of the axTLS project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE COPYRIGHT OWNER 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. + */ + +/** + * An implementation of the RC4/ARC4 algorithm. + * Originally written by Christophe Devine. + */ + +#include +#include "os_port.h" +#include "crypto.h" + +/** + * Get ready for an encrypt/decrypt operation + */ +void RC4_setup(RC4_CTX *ctx, const uint8_t *key, int length) +{ + int i, j = 0, k = 0, a; + uint8_t *m; + + ctx->x = 0; + ctx->y = 0; + m = ctx->m; + + for (i = 0; i < 256; i++) + m[i] = i; + + for (i = 0; i < 256; i++) + { + a = m[i]; + j = (uint8_t)(j + a + key[k]); + m[i] = m[j]; + m[j] = a; + + if (++k >= length) + k = 0; + } +} + +/** + * Perform the encrypt/decrypt operation (can use it for either since + * this is a stream cipher). + * NOTE: *msg and *out must be the same pointer (performance tweak) + */ +void RC4_crypt(RC4_CTX *ctx, const uint8_t *msg, uint8_t *out, int length) +{ + int i; + uint8_t *m, x, y, a, b; + + x = ctx->x; + y = ctx->y; + m = ctx->m; + + for (i = 0; i < length; i++) + { + a = m[++x]; + y += a; + m[x] = b = m[y]; + m[y] = a; + out[i] ^= m[(uint8_t)(a + b)]; + } + + ctx->x = x; + ctx->y = y; +} -- cgit v1.2.3