/* * File name: aes_stm8.c * Date first: 12/05/2017 * Date last: 12/17/2017 * * Description: AES 128-bit code for STM8 processor. * * Author: Richard Hodges * ****************************************************************************** * * Copyright (C) 2017 Richard Hodges. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * If you wish to license this code under different terms, please * contact the author: richard@hodges.org * ****************************************************************************** * * Includes */ #include #include "aes_stm8.h" /****************************************************************************** * * Differences between SDCC and COSMIC * * Note that SDCC pushes all pointers on the stack before calling, and * Cosmic puts the rightmost (or only) pointer in X. There is only one * assembly function that takes two pointers, and it has to deal with * the Cosmic compiler making all calls far. The others can just use * the pointer given in X. */ //#define COSMIC /* if not defined, assume SDCC */ /****************************************************************************** * * Locals */ static void round_enc(AES_CTX *); static void round_dec(AES_CTX *); static void mix_col_dec(BYTE *); static void mix_col_enc(BYTE *); static BYTE mix_mul2(BYTE); static BYTE sbox_enc(BYTE); static void sbox_enc_block(BYTE *); static void sbox_dec_block(BYTE *); static void mix_key(BYTE *, BYTE *); static void shift_dec(BYTE *); static void shift_enc(BYTE *); /****************************************************************************** * * Encrypt a block using this library * * in: key, block */ void aes_encrypt(AES_CTX *ctx, BYTE *block) { int i; ctx->block = block; mix_key(block, ctx->key[0]); ctx->round = 1; for (i = 0; i < 10; i++) { round_enc(ctx); } } /****************************************************************************** * * Decrypt a block using this library * * in: key, block */ void aes_decrypt(AES_CTX *ctx, BYTE *block) { int i; ctx->block = block; ctx->round = 11; for (i = 0; i < 10; i++) { round_dec(ctx); } mix_key(block, ctx->key[0]); } /****************************************************************************** * * Do decryption round * * in: AES_CTX */ static void round_dec(AES_CTX *ctx) { int r; ctx->round--; r = ctx->round; mix_key(ctx->block, ctx->key[r]); if (ctx->round != 10) { mix_col_dec(ctx->block + 0); mix_col_dec(ctx->block + 4); mix_col_dec(ctx->block + 8); mix_col_dec(ctx->block + 12); } shift_dec(ctx->block); sbox_dec_block(ctx->block); } /****************************************************************************** * * Do encryption round * * in: AES_CTX */ static void round_enc(AES_CTX *ctx) { int r; sbox_enc_block(ctx->block); shift_enc(ctx->block); if (ctx->round != 10) { mix_col_enc(ctx->block + 0); mix_col_enc(ctx->block + 4); mix_col_enc(ctx->block + 8); mix_col_enc(ctx->block + 12); } r = ctx->round; mix_key(ctx->block, ctx->key[r]); ctx->round++; } /****************************************************************************** * * Shift block rows, decrypt * * in: block */ static void shift_dec(BYTE *block) { #ifdef ORIG_C BYTE temp; temp = block[1]; block[ 1] = block[13]; block[13] = block[ 9]; block[ 9] = block[ 5]; block[ 5] = temp; temp = block[ 2]; block[ 2] = block[10]; block[10] = temp; temp = block[ 6]; block[ 6] = block[14]; block[14] = temp; temp = block[ 3]; block[ 3] = block[ 7]; block[ 7] = block[11]; block[11] = block[15]; block[15] = temp; #else block; #ifdef COSMIC #asm #else __asm ldw x, (3, sp) #endif ld a, (1, x) ld yl, a ld a, (13, x) ld (1, x), a ld a, (9, x) ld (13, x), a ld a, (5, x) ld (9, x), a ld a, yl ld (5, x), a ld a, (2, x) ld yl, a ld a, (10, x) ld (2, x), a ld a, yl ld (10, x), a ld a, (6, x) ld yl, a ld a, (14, x) ld (6, x), a ld a, yl ld (14, x), a ld a, (3, x) ld yl, a ld a, (7, x) ld (3, x), a ld a, (11, x) ld (7, x), a ld a, (15, x) ld (11, x), a ld a, yl ld (15, x), a #ifdef COSMIC #endasm #else __endasm; #endif #endif } /****************************************************************************** * * Shift block rows, encrypt * * in: block */ static void shift_enc(BYTE *block) { #ifdef ORIG_C BYTE temp; temp = block[1]; block[ 1] = block[ 5]; block[ 5] = block[ 9]; block[ 9] = block[13]; block[13] = temp; temp = block[ 2]; block[ 2] = block[10]; block[10] = temp; temp = block[ 6]; block[ 6] = block[14]; block[14] = temp; temp = block[15]; block[15] = block[11]; block[11] = block[ 7]; block[ 7] = block[ 3]; block[ 3] = temp; #else block; #ifdef COSMIC #asm #else __asm ldw x, (3, sp) #endif ld a, (1, x) ld yl, a ld a, (5, x) ld (1, x), a ld a, (9, x) ld (5, x), a ld a, (13, x) ld (9, x), a ld a, yl ld (13, x), a ld a, (2, x) ld yl, a ld a, (10, x) ld (2, x), a ld a, yl ld (10, x), a ld a, (6, x) ld yl ,a ld a, (14, x) ld (6, x), a ld a, yl ld (14, x), a ld a, (15, x) ld yl, a ld a, (11, x) ld (15, x), a ld a, (7, x) ld (11, x), a ld a, (3, x) ld (7, x), a ld a, yl ld (3, x), a #ifdef COSMIC #endasm #else __endasm; #endif #endif } /****************************************************************************** * * Multiply by two for mix operation */ #ifdef ORIG_C static BYTE mix_mul2(BYTE val) { BYTE retval; retval = val << 1; if (val & 0x80) retval ^= 0x1b; return (retval); } #endif /****************************************************************************** * * Mix column, encryption * * in: column */ static void mix_col_enc(BYTE *c) { #ifdef ORIG_C BYTE x1[4]; BYTE x2[4]; BYTE x3[4]; int i; for (i = 0; i < 4; i++) { x1[i] = c[i]; x2[i] = mix_mul2(x1[i]); x3[i] = x2[i] ^ x1[i]; } c[0] = x2[0] ^ x3[1] ^ x1[2] ^ x1[3]; c[1] = x1[0] ^ x2[1] ^ x3[2] ^ x1[3]; c[2] = x1[0] ^ x1[1] ^ x2[2] ^ x3[3]; c[3] = x3[0] ^ x1[1] ^ x1[2] ^ x2[3]; #else c; /* SP + 13, 14 return pointer * SP + 10..12 col 3 x1, x2, x3 * SP + 7..9 col 2 x1, x2, x3 * SP + 4..6 col 1 x1, x2, x3 * SP + 1..3 col 0 x1, x2, x3 */ #ifdef COSMIC #asm exgw x, y ; y is column pointer #else __asm ldw y, (3, sp) ; y is column pointer #endif clrw x sub sp, #12 ld a, (0, y) ld xl, a ld (1, sp), a ld a, (_mix_2, x) ld (2, sp), a ld a, (_mix_3, x) ld (3, sp), a ld a, (1, y) ld xl, a ld (4, sp), a ld a, (_mix_2, x) ld (5, sp), a ld a, (_mix_3, x) ld (6, sp), a ld a, (2, y) ld xl, a ld (7, sp), a ld a, (_mix_2, x) ld (8, sp), a ld a, (_mix_3, x) ld (9, sp), a ld a, (3, y) ld xl, a ld (10, sp), a ld a, (_mix_2, x) ld (11, sp), a ld a, (_mix_3, x) ld (12, sp), a exgw x, y ld a, (2, sp) ; col0 x2 xor a, (6, sp) ; col1 x3 xor a, (7, sp) ; col2 x1 xor a, (10, sp) ; col3 x1 ld (0, x), a ld a, (1, sp) ; col0 x1 xor a, (5, sp) ; col1 x2 xor a, (9, sp) ; col2 x3 xor a, (10, sp) ; col4 x1 ld (1, x), a ld a, (1, sp) ; col0 x1 xor a, (4, sp) ; col1 x1 xor a, (8, sp) ; col2 x2 xor a, (12, sp) ; col3 x3 ld (2, x), a ld a, (3, sp) ; col0 x3 xor a, (4, sp) ; col1 x1 xor a, (7, sp) ; col2 x1 xor a, (11, sp) ; col3 x2 ld (3, x), a add sp, #12 #ifdef COSMIC #endasm #else __endasm; #endif #endif } /****************************************************************************** * * Mix column, decryption * * in: column */ static void mix_col_dec(BYTE *c) { #ifdef ORIG_C BYTE x9[4]; BYTE xb[4]; BYTE xd[4]; BYTE xe[4]; int i, val; for (i = 0; i < 4; i++) { val = c[i]; x9[i] = val; xb[i] = val; xd[i] = val; val = mix_mul2(val); /* *2 */ xb[i] ^= val; xe[i] = val; val = mix_mul2(val); /* *4 */ xd[i] ^= val; xe[i] ^= val; val = mix_mul2(val); /* *8 */ x9[i] ^= val; xb[i] ^= val; xd[i] ^= val; xe[i] ^= val; } c[0] = xe[0] ^ xb[1] ^ xd[2] ^ x9[3]; c[1] = x9[0] ^ xe[1] ^ xb[2] ^ xd[3]; c[2] = xd[0] ^ x9[1] ^ xe[2] ^ xb[3]; c[3] = xb[0] ^ xd[1] ^ x9[2] ^ xe[3]; #else c; /* SP + 19, 20 column pointer * SP + 17, 18 return pointer * SP + 13..16 col 3 x9, x11, x13, x14 values * SP + 9..12 col 2 x9, x11, x13, x14 values * SP + 5.. 8 col 1 x9, x11, x13, x14 values * SP + 1.. 4 col 0 x9, x11, x13, x14 values */ #ifdef COSMIC #asm exgw x, y ; y is column pointer #else __asm ldw y, (3, sp) ; y is column pointer #endif clrw x sub sp, #16 ld a, (y) ld xl, a ld a, (_mix_9, x) ld (1, sp), a ld a, (_mix_11, x) ld (2, sp), a ld a, (_mix_13, x) ld (3, sp), a ld a, (_mix_14, x) ld (4, sp), a ld a, (1, y) ld xl, a ld a, (_mix_9, x) ld (5, sp), a ld a, (_mix_11, x) ld (6, sp), a ld a, (_mix_13, x) ld (7, sp), a ld a, (_mix_14, x) ld (8, sp), a ld a, (2, y) ld xl, a ld a, (_mix_9, x) ld (9, sp), a ld a, (_mix_11, x) ld (10, sp), a ld a, (_mix_13, x) ld (11, sp), a ld a, (_mix_14, x) ld (12, sp), a ld a, (3, y) ld xl, a ld a, (_mix_9, x) ld (13, sp), a ld a, (_mix_11, x) ld (14, sp), a ld a, (_mix_13, x) ld (15, sp), a ld a, (_mix_14, x) ld (16, sp), a ld a, (4, sp) ; col 0 x14 xor a, (6, sp) ; col 1 x11 xor a, (11, sp) ; col 2 x13 xor a, (13, sp) ; col 3 x9 ld (y), a ld a, (1, sp) ; col 0 x9 xor a, (8, sp) ; col 1 x14 xor a, (10, sp) ; col 2 x11 xor a, (15, sp) ; col 3 x13 ld (1, y), a ld a, (3, sp) ; col 0 x13 xor a, (5, sp) ; col 1 x9 xor a, (12, sp) ; col 2 x14 xor a, (14, sp) ; col 3 x11 ld (2, y), a ld a, (2, sp) ; col 0 x11 xor a, (7, sp) ; col 1 x13 xor a, (9, sp) ; col 2 x9 xor a, (16, sp) ; col 3 x14 ld (3, y), a add sp, #16 #ifdef COSMIC #endasm #else __endasm; #endif #endif } /****************************************************************************** * * SBOX values, encryption */ const BYTE sbox_tab_enc[256] = { 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }; /****************************************************************************** * * SBOX lookup, encryption * * in: index value * out: new value */ static BYTE sbox_enc(BYTE val) { return (sbox_tab_enc[val]); /* Don't optimize, only used for key gen */ } /****************************************************************************** * * SBOX block substitution, encoding * * in: block */ void sbox_enc_block(BYTE *block) { block; #ifdef COSMIC #asm exgw x, y #else __asm ldw y, (3, sp) #endif clrw x ld a, (y) ld xl, a ld a, (_sbox_tab_enc, x) ld (y), a ld a, (1, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (1, y), a ld a, (2, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (2, y), a ld a, (3, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (3, y), a ld a, (4, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (4, y), a ld a, (5, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (5, y), a ld a, (6, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (6, y), a ld a, (7, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (7, y), a ld a, (8, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (8, y), a ld a, (9, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (9, y), a ld a, (10, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (10, y), a ld a, (11, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (11, y), a ld a, (12, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (12, y), a ld a, (13, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (13, y), a ld a, (14, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (14, y), a ld a, (15, y) ld xl, a ld a, (_sbox_tab_enc, x) ld (15, y), a #ifdef COSMIC #endasm #else __endasm; #endif } /****************************************************************************** * * SBOX block substitution, decoding * * in: block */ void sbox_dec_block(BYTE *block) { block; #ifdef COSMIC #asm exgw x, y #else __asm ldw y, (3, sp) #endif clrw x ld a, (y) ld xl, a ld a, (_sbox_tab_dec, x) ld (y), a ld a, (1, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (1, y), a ld a, (2, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (2, y), a ld a, (3, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (3, y), a ld a, (4, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (4, y), a ld a, (5, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (5, y), a ld a, (6, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (6, y), a ld a, (7, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (7, y), a ld a, (8, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (8, y), a ld a, (9, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (9, y), a ld a, (10, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (10, y), a ld a, (11, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (11, y), a ld a, (12, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (12, y), a ld a, (13, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (13, y), a ld a, (14, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (14, y), a ld a, (15, y) ld xl, a ld a, (_sbox_tab_dec, x) ld (15, y), a #ifdef COSMIC #endasm #else __endasm; #endif } /****************************************************************************** * * SBOX values, decryption */ const BYTE sbox_tab_dec[256] = { 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06, 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e, 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d }; /****************************************************************************** * * Apply key to block */ static void mix_key(BYTE *block, BYTE *key) { #ifdef ORIG_C int i; for (i = 0; i < 16; i++) *block++ ^= *key++; #else block; key; #ifdef COSMIC #asm ldw x, (1, sp) ldw y, (6, sp) #else __asm ldw x, (3, sp) ; block ldw y, (5, sp) ; key #endif ld a, (x) xor a, (y) ld (x), a ld a, (1, x) xor a, (1, y) ld (1, x), a ld a, (2, x) xor a, (2, y) ld (2, x), a ld a, (3, x) xor a, (3, y) ld (3, x), a ld a, (4, x) xor a, (4, y) ld (4, x), a ld a, (5, x) xor a, (5, y) ld (5, x), a ld a, (6, x) xor a, (6, y) ld (6, x), a ld a, (7, x) xor a, (7, y) ld (7, x), a ld a, (8, x) xor a, (8, y) ld (8, x), a ld a, (9, x) xor a, (9, y) ld (9, x), a ld a, (10, x) xor a, (10, y) ld (10, x), a ld a, (11, x) xor a, (11, y) ld (11, x), a ld a, (12, x) xor a, (12, y) ld (12, x), a ld a, (13, x) xor a, (13, y) ld (13, x), a ld a, (14, x) xor a, (14, y) ld (14, x), a ld a, (15, x) xor a, (15, y) ld (15, x), a #ifdef COSMIC #endasm #else __endasm; #endif #endif } /****************************************************************************** * * Setup AES key * * in: AES_CTX, new key * * Please note: The author expects that the AES key will rarely change on * a device, and this function is not optimized. It uses 3982 cycles on the * COSMIC simulator. If your application changes keys frequently and you wish * for an optimized function, please contact me: richard@hodges.org */ void aes_new_key(AES_CTX *ctx, BYTE *key) { BYTE *kptr; int rcon; int i, j; BYTE t1, t2, t3, t4, tt; memcpy(ctx->key[0], key, 16); rcon = 1; kptr = ctx->key[1]; t1 = kptr[-4]; t2 = kptr[-3]; t3 = kptr[-2]; t4 = kptr[-1]; for (i = 1; i < 11; i++) { for (j = 0; j < 4; j++) { if (j == 0) { tt = sbox_enc(t1); t1 = sbox_enc(t2) ^ rcon; t2 = sbox_enc(t3); t3 = sbox_enc(t4); t4 = tt; } t1 ^= kptr[-16]; t2 ^= kptr[-15]; t3 ^= kptr[-14]; t4 ^= kptr[-13]; kptr[0] = t1; kptr[1] = t2; kptr[2] = t3; kptr[3] = t4; kptr += 4; } rcon <<= 1; if (rcon & 0x100) rcon ^= 0x1b; } } #include "aes_tables.h" /* column mix lookup tables */