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https://github.com/vanhoefm/fragattacks.git
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8e2c104fa1
Mainly, this is including header files to get definitions for functions which is good to verify that the parameters match. None of these are issues that would have shown as incorrect behavior of the program.
125 lines
3.0 KiB
C
125 lines
3.0 KiB
C
/*
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* One-key CBC MAC (OMAC1) hash with AES-128
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*
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* Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Alternatively, this software may be distributed under the terms of BSD
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* license.
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*
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* See README and COPYING for more details.
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*/
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#include "includes.h"
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#include "common.h"
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#include "aes.h"
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#include "aes_wrap.h"
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static void gf_mulx(u8 *pad)
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{
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int i, carry;
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carry = pad[0] & 0x80;
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for (i = 0; i < AES_BLOCK_SIZE - 1; i++)
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pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
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pad[AES_BLOCK_SIZE - 1] <<= 1;
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if (carry)
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pad[AES_BLOCK_SIZE - 1] ^= 0x87;
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}
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/**
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* omac1_aes_128_vector - One-Key CBC MAC (OMAC1) hash with AES-128
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* @key: 128-bit key for the hash operation
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* @num_elem: Number of elements in the data vector
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* @addr: Pointers to the data areas
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* @len: Lengths of the data blocks
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* @mac: Buffer for MAC (128 bits, i.e., 16 bytes)
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* Returns: 0 on success, -1 on failure
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*
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* This is a mode for using block cipher (AES in this case) for authentication.
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* OMAC1 was standardized with the name CMAC by NIST in a Special Publication
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* (SP) 800-38B.
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*/
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int omac1_aes_128_vector(const u8 *key, size_t num_elem,
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const u8 *addr[], const size_t *len, u8 *mac)
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{
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void *ctx;
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u8 cbc[AES_BLOCK_SIZE], pad[AES_BLOCK_SIZE];
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const u8 *pos, *end;
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size_t i, e, left, total_len;
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ctx = aes_encrypt_init(key, 16);
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if (ctx == NULL)
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return -1;
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os_memset(cbc, 0, AES_BLOCK_SIZE);
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total_len = 0;
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for (e = 0; e < num_elem; e++)
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total_len += len[e];
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left = total_len;
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e = 0;
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pos = addr[0];
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end = pos + len[0];
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while (left >= AES_BLOCK_SIZE) {
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for (i = 0; i < AES_BLOCK_SIZE; i++) {
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cbc[i] ^= *pos++;
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if (pos >= end) {
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e++;
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pos = addr[e];
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end = pos + len[e];
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}
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}
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if (left > AES_BLOCK_SIZE)
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aes_encrypt(ctx, cbc, cbc);
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left -= AES_BLOCK_SIZE;
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}
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os_memset(pad, 0, AES_BLOCK_SIZE);
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aes_encrypt(ctx, pad, pad);
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gf_mulx(pad);
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if (left || total_len == 0) {
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for (i = 0; i < left; i++) {
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cbc[i] ^= *pos++;
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if (pos >= end) {
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e++;
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pos = addr[e];
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end = pos + len[e];
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}
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}
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cbc[left] ^= 0x80;
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gf_mulx(pad);
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}
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for (i = 0; i < AES_BLOCK_SIZE; i++)
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pad[i] ^= cbc[i];
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aes_encrypt(ctx, pad, mac);
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aes_encrypt_deinit(ctx);
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return 0;
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}
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/**
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* omac1_aes_128 - One-Key CBC MAC (OMAC1) hash with AES-128 (aka AES-CMAC)
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* @key: 128-bit key for the hash operation
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* @data: Data buffer for which a MAC is determined
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* @data_len: Length of data buffer in bytes
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* @mac: Buffer for MAC (128 bits, i.e., 16 bytes)
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* Returns: 0 on success, -1 on failure
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*
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* This is a mode for using block cipher (AES in this case) for authentication.
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* OMAC1 was standardized with the name CMAC by NIST in a Special Publication
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* (SP) 800-38B.
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*/
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int omac1_aes_128(const u8 *key, const u8 *data, size_t data_len, u8 *mac)
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{
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return omac1_aes_128_vector(key, 1, &data, &data_len, mac);
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}
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