1 files changed, 181 insertions, 0 deletions

diff --git a/crypto/michael_mic.c b/crypto/michael_mic.c
new file mode 100644
index 000000000000..a470bcb3693e
--- /dev/null
+++ b/crypto/michael_mic.c
@@ -0,0 +1,181 @@
+/*
+ * 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 xswap(u32 val)
+{
+        return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8);
+}
+
+
+#define michael_block(l, r)     \
+do {                            \
+        r ^= rol32(l, 17);      \
+        l += r;                 \
+        r ^= xswap(l);          \
+        l += r;                 \
+        r ^= rol32(l, 3);       \
+        l += r;                 \
+        r ^= ror32(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>");