1214501Srpaulo/* 2214501Srpaulo * AES (Rijndael) cipher - encrypt 3214501Srpaulo * 4214501Srpaulo * Modifications to public domain implementation: 5214501Srpaulo * - support only 128-bit keys 6214501Srpaulo * - cleanup 7214501Srpaulo * - use C pre-processor to make it easier to change S table access 8214501Srpaulo * - added option (AES_SMALL_TABLES) for reducing code size by about 8 kB at 9214501Srpaulo * cost of reduced throughput (quite small difference on Pentium 4, 10214501Srpaulo * 10-25% when using -O1 or -O2 optimization) 11214501Srpaulo * 12214501Srpaulo * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> 13214501Srpaulo * 14214501Srpaulo * This program is free software; you can redistribute it and/or modify 15214501Srpaulo * it under the terms of the GNU General Public License version 2 as 16214501Srpaulo * published by the Free Software Foundation. 17214501Srpaulo * 18214501Srpaulo * Alternatively, this software may be distributed under the terms of BSD 19214501Srpaulo * license. 20214501Srpaulo * 21214501Srpaulo * See README and COPYING for more details. 22214501Srpaulo */ 23214501Srpaulo 24214501Srpaulo#include "includes.h" 25214501Srpaulo 26214501Srpaulo#include "common.h" 27214501Srpaulo#include "crypto.h" 28214501Srpaulo#include "aes_i.h" 29214501Srpaulo 30214501Srpaulovoid rijndaelEncrypt(const u32 rk[/*44*/], const u8 pt[16], u8 ct[16]) 31214501Srpaulo{ 32214501Srpaulo u32 s0, s1, s2, s3, t0, t1, t2, t3; 33214501Srpaulo const int Nr = 10; 34214501Srpaulo#ifndef FULL_UNROLL 35214501Srpaulo int r; 36214501Srpaulo#endif /* ?FULL_UNROLL */ 37214501Srpaulo 38214501Srpaulo /* 39214501Srpaulo * map byte array block to cipher state 40214501Srpaulo * and add initial round key: 41214501Srpaulo */ 42214501Srpaulo s0 = GETU32(pt ) ^ rk[0]; 43214501Srpaulo s1 = GETU32(pt + 4) ^ rk[1]; 44214501Srpaulo s2 = GETU32(pt + 8) ^ rk[2]; 45214501Srpaulo s3 = GETU32(pt + 12) ^ rk[3]; 46214501Srpaulo 47214501Srpaulo#define ROUND(i,d,s) \ 48214501Srpaulod##0 = TE0(s##0) ^ TE1(s##1) ^ TE2(s##2) ^ TE3(s##3) ^ rk[4 * i]; \ 49214501Srpaulod##1 = TE0(s##1) ^ TE1(s##2) ^ TE2(s##3) ^ TE3(s##0) ^ rk[4 * i + 1]; \ 50214501Srpaulod##2 = TE0(s##2) ^ TE1(s##3) ^ TE2(s##0) ^ TE3(s##1) ^ rk[4 * i + 2]; \ 51214501Srpaulod##3 = TE0(s##3) ^ TE1(s##0) ^ TE2(s##1) ^ TE3(s##2) ^ rk[4 * i + 3] 52214501Srpaulo 53214501Srpaulo#ifdef FULL_UNROLL 54214501Srpaulo 55214501Srpaulo ROUND(1,t,s); 56214501Srpaulo ROUND(2,s,t); 57214501Srpaulo ROUND(3,t,s); 58214501Srpaulo ROUND(4,s,t); 59214501Srpaulo ROUND(5,t,s); 60214501Srpaulo ROUND(6,s,t); 61214501Srpaulo ROUND(7,t,s); 62214501Srpaulo ROUND(8,s,t); 63214501Srpaulo ROUND(9,t,s); 64214501Srpaulo 65214501Srpaulo rk += Nr << 2; 66214501Srpaulo 67214501Srpaulo#else /* !FULL_UNROLL */ 68214501Srpaulo 69214501Srpaulo /* Nr - 1 full rounds: */ 70214501Srpaulo r = Nr >> 1; 71214501Srpaulo for (;;) { 72214501Srpaulo ROUND(1,t,s); 73214501Srpaulo rk += 8; 74214501Srpaulo if (--r == 0) 75214501Srpaulo break; 76214501Srpaulo ROUND(0,s,t); 77214501Srpaulo } 78214501Srpaulo 79214501Srpaulo#endif /* ?FULL_UNROLL */ 80214501Srpaulo 81214501Srpaulo#undef ROUND 82214501Srpaulo 83214501Srpaulo /* 84214501Srpaulo * apply last round and 85214501Srpaulo * map cipher state to byte array block: 86214501Srpaulo */ 87214501Srpaulo s0 = TE41(t0) ^ TE42(t1) ^ TE43(t2) ^ TE44(t3) ^ rk[0]; 88214501Srpaulo PUTU32(ct , s0); 89214501Srpaulo s1 = TE41(t1) ^ TE42(t2) ^ TE43(t3) ^ TE44(t0) ^ rk[1]; 90214501Srpaulo PUTU32(ct + 4, s1); 91214501Srpaulo s2 = TE41(t2) ^ TE42(t3) ^ TE43(t0) ^ TE44(t1) ^ rk[2]; 92214501Srpaulo PUTU32(ct + 8, s2); 93214501Srpaulo s3 = TE41(t3) ^ TE42(t0) ^ TE43(t1) ^ TE44(t2) ^ rk[3]; 94214501Srpaulo PUTU32(ct + 12, s3); 95214501Srpaulo} 96214501Srpaulo 97214501Srpaulo 98214501Srpaulovoid * aes_encrypt_init(const u8 *key, size_t len) 99214501Srpaulo{ 100214501Srpaulo u32 *rk; 101214501Srpaulo if (len != 16) 102214501Srpaulo return NULL; 103214501Srpaulo rk = os_malloc(AES_PRIV_SIZE); 104214501Srpaulo if (rk == NULL) 105214501Srpaulo return NULL; 106214501Srpaulo rijndaelKeySetupEnc(rk, key); 107214501Srpaulo return rk; 108214501Srpaulo} 109214501Srpaulo 110214501Srpaulo 111214501Srpaulovoid aes_encrypt(void *ctx, const u8 *plain, u8 *crypt) 112214501Srpaulo{ 113214501Srpaulo rijndaelEncrypt(ctx, plain, crypt); 114214501Srpaulo} 115214501Srpaulo 116214501Srpaulo 117214501Srpaulovoid aes_encrypt_deinit(void *ctx) 118214501Srpaulo{ 119214501Srpaulo os_memset(ctx, 0, AES_PRIV_SIZE); 120214501Srpaulo os_free(ctx); 121214501Srpaulo} 122