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https://github.com/vanhoefm/fragattacks.git
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d140db6adf
This adds 192-bit and 256-bit key support to the internal AES implementation and extends the AES-GCM functions to accept key length to enable longer AES key use. Signed-hostap: Jouni Malinen <j@w1.fi>
127 lines
2.6 KiB
C
127 lines
2.6 KiB
C
/*
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* AES (Rijndael) cipher - encrypt
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*
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* Modifications to public domain implementation:
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* - cleanup
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* - use C pre-processor to make it easier to change S table access
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* - added option (AES_SMALL_TABLES) for reducing code size by about 8 kB at
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* cost of reduced throughput (quite small difference on Pentium 4,
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* 10-25% when using -O1 or -O2 optimization)
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*
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* Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
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*
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* This software may be distributed under the terms of the BSD license.
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* See README 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 "crypto.h"
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#include "aes_i.h"
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static void rijndaelEncrypt(const u32 rk[], int Nr, const u8 pt[16], u8 ct[16])
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{
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u32 s0, s1, s2, s3, t0, t1, t2, t3;
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#ifndef FULL_UNROLL
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int r;
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#endif /* ?FULL_UNROLL */
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/*
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* map byte array block to cipher state
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* and add initial round key:
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*/
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s0 = GETU32(pt ) ^ rk[0];
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s1 = GETU32(pt + 4) ^ rk[1];
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s2 = GETU32(pt + 8) ^ rk[2];
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s3 = GETU32(pt + 12) ^ rk[3];
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#define ROUND(i,d,s) \
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d##0 = TE0(s##0) ^ TE1(s##1) ^ TE2(s##2) ^ TE3(s##3) ^ rk[4 * i]; \
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d##1 = TE0(s##1) ^ TE1(s##2) ^ TE2(s##3) ^ TE3(s##0) ^ rk[4 * i + 1]; \
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d##2 = TE0(s##2) ^ TE1(s##3) ^ TE2(s##0) ^ TE3(s##1) ^ rk[4 * i + 2]; \
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d##3 = TE0(s##3) ^ TE1(s##0) ^ TE2(s##1) ^ TE3(s##2) ^ rk[4 * i + 3]
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#ifdef FULL_UNROLL
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ROUND(1,t,s);
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ROUND(2,s,t);
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ROUND(3,t,s);
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ROUND(4,s,t);
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ROUND(5,t,s);
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ROUND(6,s,t);
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ROUND(7,t,s);
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ROUND(8,s,t);
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ROUND(9,t,s);
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if (Nr > 10) {
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ROUND(10,s,t);
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ROUND(11,t,s);
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if (Nr > 12) {
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ROUND(12,s,t);
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ROUND(13,t,s);
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}
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}
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rk += Nr << 2;
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#else /* !FULL_UNROLL */
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/* Nr - 1 full rounds: */
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r = Nr >> 1;
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for (;;) {
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ROUND(1,t,s);
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rk += 8;
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if (--r == 0)
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break;
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ROUND(0,s,t);
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}
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#endif /* ?FULL_UNROLL */
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#undef ROUND
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/*
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* apply last round and
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* map cipher state to byte array block:
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*/
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s0 = TE41(t0) ^ TE42(t1) ^ TE43(t2) ^ TE44(t3) ^ rk[0];
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PUTU32(ct , s0);
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s1 = TE41(t1) ^ TE42(t2) ^ TE43(t3) ^ TE44(t0) ^ rk[1];
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PUTU32(ct + 4, s1);
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s2 = TE41(t2) ^ TE42(t3) ^ TE43(t0) ^ TE44(t1) ^ rk[2];
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PUTU32(ct + 8, s2);
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s3 = TE41(t3) ^ TE42(t0) ^ TE43(t1) ^ TE44(t2) ^ rk[3];
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PUTU32(ct + 12, s3);
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}
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void * aes_encrypt_init(const u8 *key, size_t len)
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{
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u32 *rk;
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int res;
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rk = os_malloc(AES_PRIV_SIZE);
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if (rk == NULL)
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return NULL;
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res = rijndaelKeySetupEnc(rk, key, len * 8);
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if (res < 0) {
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os_free(rk);
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return NULL;
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}
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rk[AES_PRIV_NR_POS] = res;
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return rk;
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}
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void aes_encrypt(void *ctx, const u8 *plain, u8 *crypt)
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{
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u32 *rk = ctx;
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rijndaelEncrypt(ctx, rk[AES_PRIV_NR_POS], plain, crypt);
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}
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void aes_encrypt_deinit(void *ctx)
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{
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os_memset(ctx, 0, AES_PRIV_SIZE);
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os_free(ctx);
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}
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