arc4 support; ok millert@, fgsch@

2 files changed, 86 insertions, 0 deletions

diff --git a/sys/crypto/arc4.c b/sys/crypto/arc4.c
new file mode 100644
index 00000000000..fe621dbcd9e
--- /dev/null
+++ b/sys/crypto/arc4.c
@@ -0,0 +1,59 @@
+/*	$OpenBSD: arc4.c,v 1.1 2003/10/07 07:07:14 markus Exp $	*/
+/*
+ * Copyright (c) 2003 Markus Friedl <markus@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>                                                         
+
+#include <crypto/arc4.h> 
+
+#define RC4SWAP(x,y) \
+	do { \
+		u_int8_t t = ctx->state[x];  \
+		ctx->state[x] = ctx->state[y]; \
+		ctx->state[y] = t; \
+	} while(0)
+
+void
+rc4_keysetup(struct rc4_ctx *ctx, u_char *key, u_int32_t klen)
+{
+	u_int8_t x, y;
+	u_int32_t i;
+
+	x = y = 0;
+	for (i = 0; i < RC4STATE; i++)
+		ctx->state[i] = i;
+	for (i = 0; i < RC4STATE; i++) {
+		y = (key[x] + ctx->state[i] + y) % RC4STATE;
+		RC4SWAP(i, y);
+		x = (x + 1) % klen;
+	}
+	ctx->x = ctx->y = 0;
+}
+
+void
+rc4_crypt(struct rc4_ctx *ctx, u_char *src, u_char *dst,
+    u_int32_t len)
+{
+	u_int32_t i;
+
+	for (i = 0; i < len; i++) {
+		ctx->x = (ctx->x + 1) % RC4STATE;
+		ctx->y = (ctx->state[ctx->x] + ctx->y) % RC4STATE;
+		RC4SWAP(ctx->x, ctx->y);
+		dst[i] = src[i] ^ ctx->state[
+		   (ctx->state[ctx->x] + ctx->state[ctx->y]) % RC4STATE];
+	}
+}
diff --git a/sys/crypto/arc4.h b/sys/crypto/arc4.h
new file mode 100644
index 00000000000..2bbf9227ceb
--- /dev/null
+++ b/sys/crypto/arc4.h
@@ -0,0 +1,27 @@
+/*	$OpenBSD: arc4.h,v 1.1 2003/10/07 07:07:14 markus Exp $	*/
+/*
+ * Copyright (c) 2003 Markus Friedl <markus@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#define RC4STATE 256
+#define RC4KEYLEN 16
+
+struct rc4_ctx {
+	u_int8_t x, y;
+	u_int8_t state[RC4STATE];
+};
+
+void	rc4_keysetup(struct rc4_ctx *, u_char *, u_int32_t);
+void	rc4_crypt(struct rc4_ctx *, u_char *, u_char *, u_int32_t);