patch-2.4.27 linux-2.4.27/crypto/michael_mic.c

• Lines: 194
• Date: 2004-08-07 16:26:04.640346202 -0700
• Orig file: linux-2.4.26/crypto/michael_mic.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.26/crypto/michael_mic.c linux-2.4.27/crypto/michael_mic.c
@@ -0,0 +1,193 @@
+/*
+ * Cryptographic API
+ *
+ * Michael MIC (IEEE 802.11i/TKIP) keyed digest
+ *
+ * Copyright (c) 2004 Jouni Malinen <jkmaline@cc.hut.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/crypto.h>
+
+
+struct michael_mic_ctx {
+	u8 pending[4];
+	size_t pending_len;
+
+	u32 l, r;
+};
+
+
+static inline u32 rotl(u32 val, int bits)
+{
+	return (val << bits) | (val >> (32 - bits));
+}
+
+
+static inline u32 rotr(u32 val, int bits)
+{
+	return (val >> bits) | (val << (32 - bits));
+}
+
+
+static inline u32 xswap(u32 val)
+{
+	return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8);
+}
+
+
+#define michael_block(l, r)	\
+do {				\
+	r ^= rotl(l, 17);	\
+	l += r;			\
+	r ^= xswap(l);		\
+	l += r;			\
+	r ^= rotl(l, 3);	\
+	l += r;			\
+	r ^= rotr(l, 2);	\
+	l += r;			\
+} while (0)
+
+
+static inline u32 get_le32(const u8 *p)
+{
+	return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
+}
+
+
+static inline void put_le32(u8 *p, u32 v)
+{
+	p[0] = v;
+	p[1] = v >> 8;
+	p[2] = v >> 16;
+	p[3] = v >> 24;
+}
+
+
+static void michael_init(void *ctx)
+{
+	struct michael_mic_ctx *mctx = ctx;
+	mctx->pending_len = 0;
+}
+
+
+static void michael_update(void *ctx, const u8 *data, unsigned int len)
+{
+	struct michael_mic_ctx *mctx = ctx;
+
+	if (mctx->pending_len) {
+		int flen = 4 - mctx->pending_len;
+		if (flen > len)
+			flen = len;
+		memcpy(&mctx->pending[mctx->pending_len], data, flen);
+		mctx->pending_len += flen;
+		data += flen;
+		len -= flen;
+
+		if (mctx->pending_len < 4)
+			return;
+
+		mctx->l ^= get_le32(mctx->pending);
+		michael_block(mctx->l, mctx->r);
+		mctx->pending_len = 0;
+	}
+
+	while (len >= 4) {
+		mctx->l ^= get_le32(data);
+		michael_block(mctx->l, mctx->r);
+		data += 4;
+		len -= 4;
+	}
+
+	if (len > 0) {
+		mctx->pending_len = len;
+		memcpy(mctx->pending, data, len);
+	}
+}
+
+
+static void michael_final(void *ctx, u8 *out)
+{
+	struct michael_mic_ctx *mctx = ctx;
+	u8 *data = mctx->pending;
+
+	/* Last block and padding (0x5a, 4..7 x 0) */
+	switch (mctx->pending_len) {
+	case 0:
+		mctx->l ^= 0x5a;
+		break;
+	case 1:
+		mctx->l ^= data[0] | 0x5a00;
+		break;
+	case 2:
+		mctx->l ^= data[0] | (data[1] << 8) | 0x5a0000;
+		break;
+	case 3:
+		mctx->l ^= data[0] | (data[1] << 8) | (data[2] << 16) |
+			0x5a000000;
+		break;
+	}
+	michael_block(mctx->l, mctx->r);
+	/* l ^= 0; */
+	michael_block(mctx->l, mctx->r);
+
+	put_le32(out, mctx->l);
+	put_le32(out + 4, mctx->r);
+}
+
+
+static int michael_setkey(void *ctx, const u8 *key, unsigned int keylen,
+			  u32 *flags)
+{
+	struct michael_mic_ctx *mctx = ctx;
+	if (keylen != 8) {
+		if (flags)
+			*flags = CRYPTO_TFM_RES_BAD_KEY_LEN;
+		return -EINVAL;
+	}
+	mctx->l = get_le32(key);
+	mctx->r = get_le32(key + 4);
+	return 0;
+}
+
+
+static struct crypto_alg michael_mic_alg = {
+	.cra_name	= "michael_mic",
+	.cra_flags	= CRYPTO_ALG_TYPE_DIGEST,
+	.cra_blocksize	= 8,
+	.cra_ctxsize	= sizeof(struct michael_mic_ctx),
+	.cra_module	= THIS_MODULE,
+	.cra_list	= LIST_HEAD_INIT(michael_mic_alg.cra_list),
+	.cra_u		= { .digest = {
+	.dia_digestsize	= 8,
+	.dia_init	= michael_init,
+	.dia_update	= michael_update,
+	.dia_final	= michael_final,
+	.dia_setkey	= michael_setkey } }
+};
+
+
+static int __init michael_mic_init(void)
+{
+	return crypto_register_alg(&michael_mic_alg);
+}
+
+
+static void __exit michael_mic_exit(void)
+{
+	crypto_unregister_alg(&michael_mic_alg);
+}
+
+
+module_init(michael_mic_init);
+module_exit(michael_mic_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Michael MIC");
+MODULE_AUTHOR("Jouni Malinen <jkmaline@cc.hut.fi>");