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-rw-r--r--src/crypto/aes-omac1.c123
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diff --git a/src/crypto/aes-omac1.c b/src/crypto/aes-omac1.c
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+/*
+ * One-key CBC MAC (OMAC1) hash with AES-128
+ *
+ * Copyright (c) 2003-2007, Jouni Malinen <j@w1.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.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "aes_i.h"
+
+static void gf_mulx(u8 *pad)
+{
+ int i, carry;
+
+ carry = pad[0] & 0x80;
+ for (i = 0; i < BLOCK_SIZE - 1; i++)
+ pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
+ pad[BLOCK_SIZE - 1] <<= 1;
+ if (carry)
+ pad[BLOCK_SIZE - 1] ^= 0x87;
+}
+
+
+/**
+ * omac1_aes_128_vector - One-Key CBC MAC (OMAC1) hash with AES-128
+ * @key: 128-bit key for the hash operation
+ * @num_elem: Number of elements in the data vector
+ * @addr: Pointers to the data areas
+ * @len: Lengths of the data blocks
+ * @mac: Buffer for MAC (128 bits, i.e., 16 bytes)
+ * Returns: 0 on success, -1 on failure
+ *
+ * This is a mode for using block cipher (AES in this case) for authentication.
+ * OMAC1 was standardized with the name CMAC by NIST in a Special Publication
+ * (SP) 800-38B.
+ */
+int omac1_aes_128_vector(const u8 *key, size_t num_elem,
+ const u8 *addr[], const size_t *len, u8 *mac)
+{
+ void *ctx;
+ u8 cbc[BLOCK_SIZE], pad[BLOCK_SIZE];
+ const u8 *pos, *end;
+ size_t i, e, left, total_len;
+
+ ctx = aes_encrypt_init(key, 16);
+ if (ctx == NULL)
+ return -1;
+ os_memset(cbc, 0, BLOCK_SIZE);
+
+ total_len = 0;
+ for (e = 0; e < num_elem; e++)
+ total_len += len[e];
+ left = total_len;
+
+ e = 0;
+ pos = addr[0];
+ end = pos + len[0];
+
+ while (left >= BLOCK_SIZE) {
+ for (i = 0; i < BLOCK_SIZE; i++) {
+ cbc[i] ^= *pos++;
+ if (pos >= end) {
+ e++;
+ pos = addr[e];
+ end = pos + len[e];
+ }
+ }
+ if (left > BLOCK_SIZE)
+ aes_encrypt(ctx, cbc, cbc);
+ left -= BLOCK_SIZE;
+ }
+
+ os_memset(pad, 0, BLOCK_SIZE);
+ aes_encrypt(ctx, pad, pad);
+ gf_mulx(pad);
+
+ if (left || total_len == 0) {
+ for (i = 0; i < left; i++) {
+ cbc[i] ^= *pos++;
+ if (pos >= end) {
+ e++;
+ pos = addr[e];
+ end = pos + len[e];
+ }
+ }
+ cbc[left] ^= 0x80;
+ gf_mulx(pad);
+ }
+
+ for (i = 0; i < BLOCK_SIZE; i++)
+ pad[i] ^= cbc[i];
+ aes_encrypt(ctx, pad, mac);
+ aes_encrypt_deinit(ctx);
+ return 0;
+}
+
+
+/**
+ * omac1_aes_128 - One-Key CBC MAC (OMAC1) hash with AES-128 (aka AES-CMAC)
+ * @key: 128-bit key for the hash operation
+ * @data: Data buffer for which a MAC is determined
+ * @data_len: Length of data buffer in bytes
+ * @mac: Buffer for MAC (128 bits, i.e., 16 bytes)
+ * Returns: 0 on success, -1 on failure
+ *
+ * This is a mode for using block cipher (AES in this case) for authentication.
+ * OMAC1 was standardized with the name CMAC by NIST in a Special Publication
+ * (SP) 800-38B.
+ */
+int omac1_aes_128(const u8 *key, const u8 *data, size_t data_len, u8 *mac)
+{
+ return omac1_aes_128_vector(key, 1, &data, &data_len, mac);
+}