/* aes.c
*
* The aes/rijndael block cipher.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2000, 2001 Rafael R. Sevilla, Niels M�ller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The GNU MP Library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the GNU MP Library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
/* Originally written by Rafael R. Sevilla <dido@pacific.net.ph> */
#include "aes.h"
#include <assert.h>
/* These tables combine both the S-boxes and the mixcolumn
* transformation, so that we can perform a round's encryption or by
* means of four table lookups and four XOR's per column of state.
* They were generated by the makertbls.pl script. */
static const uint32_t dtbl[] = {
0xa56363c6, 0x847c7cf8, 0x997777ee, 0x8d7b7bf6,
0x0df2f2ff, 0xbd6b6bd6, 0xb16f6fde, 0x54c5c591,
0x50303060, 0x03010102, 0xa96767ce, 0x7d2b2b56,
0x19fefee7, 0x62d7d7b5, 0xe6abab4d, 0x9a7676ec,
0x45caca8f, 0x9d82821f, 0x40c9c989, 0x877d7dfa,
0x15fafaef, 0xeb5959b2, 0xc947478e, 0x0bf0f0fb,
0xecadad41, 0x67d4d4b3, 0xfda2a25f, 0xeaafaf45,
0xbf9c9c23, 0xf7a4a453, 0x967272e4, 0x5bc0c09b,
0xc2b7b775, 0x1cfdfde1, 0xae93933d, 0x6a26264c,
0x5a36366c, 0x413f3f7e, 0x02f7f7f5, 0x4fcccc83,
0x5c343468, 0xf4a5a551, 0x34e5e5d1, 0x08f1f1f9,
0x937171e2, 0x73d8d8ab, 0x53313162, 0x3f15152a,
0x0c040408, 0x52c7c795, 0x65232346, 0x5ec3c39d,
0x28181830, 0xa1969637, 0x0f05050a, 0xb59a9a2f,
0x0907070e, 0x36121224, 0x9b80801b, 0x3de2e2df,
0x26ebebcd, 0x6927274e, 0xcdb2b27f, 0x9f7575ea,
0x1b090912, 0x9e83831d, 0x742c2c58, 0x2e1a1a34,
0x2d1b1b36, 0xb26e6edc, 0xee5a5ab4, 0xfba0a05b,
0xf65252a4, 0x4d3b3b76, 0x61d6d6b7, 0xceb3b37d,
0x7b292952, 0x3ee3e3dd, 0x712f2f5e, 0x97848413,
0xf55353a6, 0x68d1d1b9, 0x00000000, 0x2cededc1,
0x60202040, 0x1ffcfce3, 0xc8b1b179, 0xed5b5bb6,
0xbe6a6ad4, 0x46cbcb8d, 0xd9bebe67, 0x4b393972,
0xde4a4a94, 0xd44c4c98, 0xe85858b0, 0x4acfcf85,
0x6bd0d0bb, 0x2aefefc5, 0xe5aaaa4f, 0x16fbfbed,
0xc5434386, 0xd74d4d9a, 0x55333366, 0x94858511,
0xcf45458a, 0x10f9f9e9, 0x06020204, 0x817f7ffe,
0xf05050a0, 0x443c3c78, 0xba9f9f25, 0xe3a8a84b,
0xf35151a2, 0xfea3a35d, 0xc0404080, 0x8a8f8f05,
0xad92923f, 0xbc9d9d21, 0x48383870, 0x04f5f5f1,
0xdfbcbc63, 0xc1b6b677, 0x75dadaaf, 0x63212142,
0x30101020, 0x1affffe5, 0x0ef3f3fd, 0x6dd2d2bf,
0x4ccdcd81, 0x140c0c18, 0x35131326, 0x2fececc3,
0xe15f5fbe, 0xa2979735, 0xcc444488, 0x3917172e,
0x57c4c493, 0xf2a7a755, 0x827e7efc, 0x473d3d7a,
0xac6464c8, 0xe75d5dba, 0x2b191932, 0x957373e6,
0xa06060c0, 0x98818119, 0xd14f4f9e, 0x7fdcdca3,
0x66222244, 0x7e2a2a54, 0xab90903b, 0x8388880b,
0xca46468c, 0x29eeeec7, 0xd3b8b86b, 0x3c141428,
0x79dedea7, 0xe25e5ebc, 0x1d0b0b16, 0x76dbdbad,
0x3be0e0db, 0x56323264, 0x4e3a3a74, 0x1e0a0a14,
0xdb494992, 0x0a06060c, 0x6c242448, 0xe45c5cb8,
0x5dc2c29f, 0x6ed3d3bd, 0xefacac43, 0xa66262c4,
0xa8919139, 0xa4959531, 0x37e4e4d3, 0x8b7979f2,
0x32e7e7d5, 0x43c8c88b, 0x5937376e, 0xb76d6dda,
0x8c8d8d01, 0x64d5d5b1, 0xd24e4e9c, 0xe0a9a949,
0xb46c6cd8, 0xfa5656ac, 0x07f4f4f3, 0x25eaeacf,
0xaf6565ca, 0x8e7a7af4, 0xe9aeae47, 0x18080810,
0xd5baba6f, 0x887878f0, 0x6f25254a, 0x722e2e5c,
0x241c1c38, 0xf1a6a657, 0xc7b4b473, 0x51c6c697,
0x23e8e8cb, 0x7cdddda1, 0x9c7474e8, 0x211f1f3e,
0xdd4b4b96, 0xdcbdbd61, 0x868b8b0d, 0x858a8a0f,
0x907070e0, 0x423e3e7c, 0xc4b5b571, 0xaa6666cc,
0xd8484890, 0x05030306, 0x01f6f6f7, 0x120e0e1c,
0xa36161c2, 0x5f35356a, 0xf95757ae, 0xd0b9b969,
0x91868617, 0x58c1c199, 0x271d1d3a, 0xb99e9e27,
0x38e1e1d9, 0x13f8f8eb, 0xb398982b, 0x33111122,
0xbb6969d2, 0x70d9d9a9, 0x898e8e07, 0xa7949433,
0xb69b9b2d, 0x221e1e3c, 0x92878715, 0x20e9e9c9,
0x49cece87, 0xff5555aa, 0x78282850, 0x7adfdfa5,
0x8f8c8c03, 0xf8a1a159, 0x80898909, 0x170d0d1a,
0xdabfbf65, 0x31e6e6d7, 0xc6424284, 0xb86868d0,
0xc3414182, 0xb0999929, 0x772d2d5a, 0x110f0f1e,
0xcbb0b07b, 0xfc5454a8, 0xd6bbbb6d, 0x3a16162c,
};
static const uint32_t itbl[] = {
0x50a7f451, 0x5365417e, 0xc3a4171a, 0x965e273a,
0xcb6bab3b, 0xf1459d1f, 0xab58faac, 0x9303e34b,
0x55fa3020, 0xf66d76ad, 0x9176cc88, 0x254c02f5,
0xfcd7e54f, 0xd7cb2ac5, 0x80443526, 0x8fa362b5,
0x495ab1de, 0x671bba25, 0x980eea45, 0xe1c0fe5d,
0x02752fc3, 0x12f04c81, 0xa397468d, 0xc6f9d36b,
0xe75f8f03, 0x959c9215, 0xeb7a6dbf, 0xda595295,
0x2d83bed4, 0xd3217458, 0x2969e049, 0x44c8c98e,
0x6a89c275, 0x78798ef4, 0x6b3e5899, 0xdd71b927,
0xb64fe1be, 0x17ad88f0, 0x66ac20c9, 0xb43ace7d,
0x184adf63, 0x82311ae5, 0x60335197, 0x457f5362,
0xe07764b1, 0x84ae6bbb, 0x1ca081fe, 0x942b08f9,
0x58684870, 0x19fd458f, 0x876cde94, 0xb7f87b52,
0x23d373ab, 0xe2024b72, 0x578f1fe3, 0x2aab5566,
0x0728ebb2, 0x03c2b52f, 0x9a7bc586, 0xa50837d3,
0xf2872830, 0xb2a5bf23, 0xba6a0302, 0x5c8216ed,
0x2b1ccf8a, 0x92b479a7, 0xf0f207f3, 0xa1e2694e,
0xcdf4da65, 0xd5be0506, 0x1f6234d1, 0x8afea6c4,
0x9d532e34, 0xa055f3a2, 0x32e18a05, 0x75ebf6a4,
0x39ec830b, 0xaaef6040, 0x069f715e, 0x51106ebd,
0xf98a213e, 0x3d06dd96, 0xae053edd, 0x46bde64d,
0xb58d5491, 0x055dc471, 0x6fd40604, 0xff155060,
0x24fb9819, 0x97e9bdd6, 0xcc434089, 0x779ed967,
0xbd42e8b0, 0x888b8907, 0x385b19e7, 0xdbeec879,
0x470a7ca1, 0xe90f427c, 0xc91e84f8, 0x00000000,
0x83868009, 0x48ed2b32, 0xac70111e, 0x4e725a6c,
0xfbff0efd, 0x5638850f, 0x1ed5ae3d, 0x27392d36,
0x64d90f0a, 0x21a65c68, 0xd1545b9b, 0x3a2e3624,
0xb1670a0c, 0x0fe75793, 0xd296eeb4, 0x9e919b1b,
0x4fc5c080, 0xa220dc61, 0x694b775a, 0x161a121c,
0x0aba93e2, 0xe52aa0c0, 0x43e0223c, 0x1d171b12,
0x0b0d090e, 0xadc78bf2, 0xb9a8b62d, 0xc8a91e14,
0x8519f157, 0x4c0775af, 0xbbdd99ee, 0xfd607fa3,
0x9f2601f7, 0xbcf5725c, 0xc53b6644, 0x347efb5b,
0x7629438b, 0xdcc623cb, 0x68fcedb6, 0x63f1e4b8,
0xcadc31d7, 0x10856342, 0x40229713, 0x2011c684,
0x7d244a85, 0xf83dbbd2, 0x1132f9ae, 0x6da129c7,
0x4b2f9e1d, 0xf330b2dc, 0xec52860d, 0xd0e3c177,
0x6c16b32b, 0x99b970a9, 0xfa489411, 0x2264e947,
0xc48cfca8, 0x1a3ff0a0, 0xd82c7d56, 0xef903322,
0xc74e4987, 0xc1d138d9, 0xfea2ca8c, 0x360bd498,
0xcf81f5a6, 0x28de7aa5, 0x268eb7da, 0xa4bfad3f,
0xe49d3a2c, 0x0d927850, 0x9bcc5f6a, 0x62467e54,
0xc2138df6, 0xe8b8d890, 0x5ef7392e, 0xf5afc382,
0xbe805d9f, 0x7c93d069, 0xa92dd56f, 0xb31225cf,
0x3b99acc8, 0xa77d1810, 0x6e639ce8, 0x7bbb3bdb,
0x097826cd, 0xf418596e, 0x01b79aec, 0xa89a4f83,
0x656e95e6, 0x7ee6ffaa, 0x08cfbc21, 0xe6e815ef,
0xd99be7ba, 0xce366f4a, 0xd4099fea, 0xd67cb029,
0xafb2a431, 0x31233f2a, 0x3094a5c6, 0xc066a235,
0x37bc4e74, 0xa6ca82fc, 0xb0d090e0, 0x15d8a733,
0x4a9804f1, 0xf7daec41, 0x0e50cd7f, 0x2ff69117,
0x8dd64d76, 0x4db0ef43, 0x544daacc, 0xdf0496e4,
0xe3b5d19e, 0x1b886a4c, 0xb81f2cc1, 0x7f516546,
0x04ea5e9d, 0x5d358c01, 0x737487fa, 0x2e410bfb,
0x5a1d67b3, 0x52d2db92, 0x335610e9, 0x1347d66d,
0x8c61d79a, 0x7a0ca137, 0x8e14f859, 0x893c13eb,
0xee27a9ce, 0x35c961b7, 0xede51ce1, 0x3cb1477a,
0x59dfd29c, 0x3f73f255, 0x79ce1418, 0xbf37c773,
0xeacdf753, 0x5baafd5f, 0x146f3ddf, 0x86db4478,
0x81f3afca, 0x3ec468b9, 0x2c342438, 0x5f40a3c2,
0x72c31d16, 0x0c25e2bc, 0x8b493c28, 0x41950dff,
0x7101a839, 0xdeb30c08, 0x9ce4b4d8, 0x90c15664,
0x6184cb7b, 0x70b632d5, 0x745c6c48, 0x4257b8d0,
};
/* Needed only for the key schedule and for final rounds */
static const uint8_t sbox[256] = {
99, 124, 119, 123, 242, 107, 111, 197, 48, 1, 103, 43, 254, 215, 171,
118, 202, 130, 201, 125, 250, 89, 71, 240, 173, 212, 162, 175, 156, 164,
114, 192, 183, 253, 147, 38, 54, 63, 247, 204, 52, 165, 229, 241, 113,
216, 49, 21, 4, 199, 35, 195, 24, 150, 5, 154, 7, 18, 128, 226,
235, 39, 178, 117, 9, 131, 44, 26, 27, 110, 90, 160, 82, 59, 214,
179, 41, 227, 47, 132, 83, 209, 0, 237, 32, 252, 177, 91, 106, 203,
190, 57, 74, 76, 88, 207, 208, 239, 170, 251, 67, 77, 51, 133, 69,
249, 2, 127, 80, 60, 159, 168, 81, 163, 64, 143, 146, 157, 56, 245,
188, 182, 218, 33, 16, 255, 243, 210, 205, 12, 19, 236, 95, 151, 68,
23, 196, 167, 126, 61, 100, 93, 25, 115, 96, 129, 79, 220, 34, 42,
144, 136, 70, 238, 184, 20, 222, 94, 11, 219, 224, 50, 58, 10, 73,
6, 36, 92, 194, 211, 172, 98, 145, 149, 228, 121, 231, 200, 55, 109,
141, 213, 78, 169, 108, 86, 244, 234, 101, 122, 174, 8, 186, 120, 37,
46, 28, 166, 180, 198, 232, 221, 116, 31, 75, 189, 139, 138, 112, 62,
181, 102, 72, 3, 246, 14, 97, 53, 87, 185, 134, 193, 29, 158, 225,
248, 152, 17, 105, 217, 142, 148, 155, 30, 135, 233, 206, 85, 40, 223,
140, 161, 137, 13, 191, 230, 66, 104, 65, 153, 45, 15, 176, 84, 187,
22,
};
static const uint8_t isbox[256] = {
82, 9, 106, 213, 48, 54, 165, 56, 191, 64, 163, 158, 129, 243, 215,
251, 124, 227, 57, 130, 155, 47, 255, 135, 52, 142, 67, 68, 196, 222,
233, 203, 84, 123, 148, 50, 166, 194, 35, 61, 238, 76, 149, 11, 66,
250, 195, 78, 8, 46, 161, 102, 40, 217, 36, 178, 118, 91, 162, 73,
109, 139, 209, 37, 114, 248, 246, 100, 134, 104, 152, 22, 212, 164, 92,
204, 93, 101, 182, 146, 108, 112, 72, 80, 253, 237, 185, 218, 94, 21,
70, 87, 167, 141, 157, 132, 144, 216, 171, 0, 140, 188, 211, 10, 247,
228, 88, 5, 184, 179, 69, 6, 208, 44, 30, 143, 202, 63, 15, 2,
193, 175, 189, 3, 1, 19, 138, 107, 58, 145, 17, 65, 79, 103, 220,
234, 151, 242, 207, 206, 240, 180, 230, 115, 150, 172, 116, 34, 231, 173,
53, 133, 226, 249, 55, 232, 28, 117, 223, 110, 71, 241, 26, 113, 29,
41, 197, 137, 111, 183, 98, 14, 170, 24, 190, 27, 252, 86, 62, 75,
198, 210, 121, 32, 154, 219, 192, 254, 120, 205, 90, 244, 31, 221, 168,
51, 136, 7, 199, 49, 177, 18, 16, 89, 39, 128, 236, 95, 96, 81,
127, 169, 25, 181, 74, 13, 45, 229, 122, 159, 147, 201, 156, 239, 160,
224, 59, 77, 174, 42, 245, 176, 200, 235, 187, 60, 131, 83, 153, 97,
23, 43, 4, 126, 186, 119, 214, 38, 225, 105, 20, 99, 85, 33, 12,
125,
};
/* Used only by the key schedule */
static const uint8_t Logtable[256] = {
0, 0, 25, 1, 50, 2, 26, 198, 75, 199, 27, 104, 51, 238, 223, 3,
100, 4, 224, 14, 52, 141, 129, 239, 76, 113, 8, 200, 248, 105, 28,
193, 125, 194, 29, 181, 249, 185, 39, 106, 77, 228, 166, 114, 154, 201,
9, 120, 101, 47, 138, 5, 33, 15, 225, 36, 18, 240, 130, 69, 53,
147, 218, 142, 150, 143, 219, 189, 54, 208, 206, 148, 19, 92, 210, 241,
64, 70, 131, 56, 102, 221, 253, 48, 191, 6, 139, 98, 179, 37, 226,
152, 34, 136, 145, 16, 126, 110, 72, 195, 163, 182, 30, 66, 58, 107,
40, 84, 250, 133, 61, 186, 43, 121, 10, 21, 155, 159, 94, 202, 78,
212, 172, 229, 243, 115, 167, 87, 175, 88, 168, 80, 244, 234, 214, 116,
79, 174, 233, 213, 231, 230, 173, 232, 44, 215, 117, 122, 235, 22, 11,
245, 89, 203, 95, 176, 156, 169, 81, 160, 127, 12, 246, 111, 23, 196,
73, 236, 216, 67, 31, 45, 164, 118, 123, 183, 204, 187, 62, 90, 251,
96, 177, 134, 59, 82, 161, 108, 170, 85, 41, 157, 151, 178, 135, 144,
97, 190, 220, 252, 188, 149, 207, 205, 55, 63, 91, 209, 83, 57, 132,
60, 65, 162, 109, 71, 20, 42, 158, 93, 86, 242, 211, 171, 68, 17,
146, 217, 35, 32, 46, 137, 180, 124, 184, 38, 119, 153, 227, 165, 103,
74, 237, 222, 197, 49, 254, 24, 13, 99, 140, 128, 192, 247, 112, 7,
};
static const uint8_t Alogtable[256] = {
1, 3, 5, 15, 17, 51, 85, 255, 26, 46, 114, 150, 161, 248, 19,
53, 95, 225, 56, 72, 216, 115, 149, 164, 247, 2, 6, 10, 30, 34,
102, 170, 229, 52, 92, 228, 55, 89, 235, 38, 106, 190, 217, 112, 144,
171, 230, 49, 83, 245, 4, 12, 20, 60, 68, 204, 79, 209, 104, 184,
211, 110, 178, 205, 76, 212, 103, 169, 224, 59, 77, 215, 98, 166, 241,
8, 24, 40, 120, 136, 131, 158, 185, 208, 107, 189, 220, 127, 129, 152,
179, 206, 73, 219, 118, 154, 181, 196, 87, 249, 16, 48, 80, 240, 11,
29, 39, 105, 187, 214, 97, 163, 254, 25, 43, 125, 135, 146, 173, 236,
47, 113, 147, 174, 233, 32, 96, 160, 251, 22, 58, 78, 210, 109, 183,
194, 93, 231, 50, 86, 250, 21, 63, 65, 195, 94, 226, 61, 71, 201,
64, 192, 91, 237, 44, 116, 156, 191, 218, 117, 159, 186, 213, 100, 172,
239, 42, 126, 130, 157, 188, 223, 122, 142, 137, 128, 155, 182, 193, 88,
232, 35, 101, 175, 234, 37, 111, 177, 200, 67, 197, 84, 252, 31, 33,
99, 165, 244, 7, 9, 27, 45, 119, 153, 176, 203, 70, 202, 69, 207,
74, 222, 121, 139, 134, 145, 168, 227, 62, 66, 198, 81, 243, 14, 18,
54, 90, 238, 41, 123, 141, 140, 143, 138, 133, 148, 167, 242, 13, 23,
57, 75, 221, 124, 132, 151, 162, 253, 28, 36, 108, 180, 199, 82, 246, 1,
};
#define ROTBYTE(x) (((x) >> 8) | (((x) & 0xff) << 24))
#define ROTRBYTE(x) (((x) << 8) | (((x) >> 24) & 0xff))
#define SUBBYTE(x, box) (((box)[((x) & 0xff)]) | \
((box)[(((x) >> 8) & 0xff)] << 8) | \
((box)[(((x) >> 16) & 0xff)] << 16) | \
((box)[(((x) >> 24) & 0xff)] << 24))
static uint8_t
xtime(uint8_t a)
{
uint8_t b;
b = (a & 0x80) ? 0x1b : 0;
a<<=1;
a^=b;
return(a);
}
static uint8_t
mul(uint8_t a, uint8_t b)
{
if (a && b) return Alogtable[(Logtable[a] + Logtable[b])%255];
else return 0;
}
static void
inv_mix_column(uint32_t *a, uint32_t *b)
{
uint8_t c[4][4];
unsigned i, j;
for(j = 0; j < 4; j++)
{
for(i = 0; i < 4; i++)
{
c[j][i] = mul(0xe, (a[j] >> i*8) & 0xff)
^ mul(0xb, (a[j] >> ((i+1)%4)*8) & 0xff)
^ mul(0xd, (a[j] >> ((i+2)%4)*8) & 0xff)
^ mul(0x9, (a[j] >> ((i+3)%4)*8) & 0xff);
}
}
for(i = 0; i < 4; i++)
{
b[i] = 0;
for(j = 0; j < 4; j++)
b[i] |= c[i][j] << (j*8);
}
}
/* FIXME: Perhaps we should have separate fucntion for encryption and decryption keys?
* It seems unnecessary to compute the inverse subkeys if we're not going to use them.
* Can one define an aes_inverse function? */
void
aes_set_key(struct aes_ctx *ctx, unsigned keysize, const uint8_t *key)
{
unsigned nk, nr, i, lastkey;
uint32_t temp, rcon;
assert(keysize >= AES_MIN_KEY_SIZE);
assert(keysize <= AES_MAX_KEY_SIZE);
/* Truncate keysizes to the valid key sizes provided by Rijndael */
if (keysize == 32) {
nk = 8;
nr = 14;
} else if (keysize >= 24) {
nk = 6;
nr = 12;
} else { /* must be 16 or more */
nk = 4;
nr = 10;
}
lastkey = (AES_BLOCK_SIZE/4) * (nr + 1);
ctx->nrounds = nr;
rcon = 1;
for (i=0; i<nk; i++)
{
ctx->keys[i] = key[i*4] + (key[i*4+1]<<8) + (key[i*4+2]<<16) +
(key[i*4+3]<<24);
}
for (i=nk; i<lastkey; i++)
{
temp = ctx->keys[i-1];
if (i % nk == 0)
{
temp = SUBBYTE(ROTBYTE(temp), sbox) ^ rcon;
rcon = (uint32_t)xtime((uint8_t)rcon&0xff);
}
else if (nk > 6 && (i%nk) == 4)
{
temp = SUBBYTE(temp, sbox);
}
ctx->keys[i] = ctx->keys[i-nk] ^ temp;
}
/* Generate the inverse keys */
for (i=0; i<4; i++)
{
ctx->ikeys[i] = ctx->keys[i];
ctx->ikeys[lastkey-4 + i] = ctx->keys[lastkey-4 + i];
}
for (i=4; i<lastkey-4; i+=4)
inv_mix_column(&(ctx->keys[i]), &(ctx->ikeys[i]));
}
/* Key addition that also packs every byte in the key to a word rep. */
static void
key_addition_8to32(const uint8_t *txt, const uint32_t *keys, uint32_t *out)
{
const uint8_t *ptr;
unsigned i, j;
uint32_t val;
ptr = txt;
for (i=0; i<4; i++)
{
/* FIXME: Use the READ_UINT32 or LE_READ_UINT32 macro. */
val = 0;
for (j=0; j<4; j++)
val |= (*ptr++ << 8*j);
out[i] = keys[i]^val;
}
}
static void
key_addition32(const uint32_t *txt, const uint32_t *keys, uint32_t *out)
{
unsigned i;
for (i=0; i<4; i++)
out[i] = keys[i] ^ txt[i];
}
static void
key_addition32to8(const uint32_t *txt, const uint32_t *keys, uint8_t *out)
{
uint8_t *ptr;
unsigned i, j;
uint32_t val;
ptr = out;
for (i=0; i<4; i++)
{
/* FIXME: Use WRITE_UINT32 or LE_WRITE_UINT32 */
val = txt[i] ^ keys[i];
for (j=0; j<4; j++)
*ptr++ = (val >> 8*j) & 0xff;
}
}
static const unsigned idx[4][4] = {
{ 0, 1, 2, 3 },
{ 1, 2, 3, 0 },
{ 2, 3, 0, 1 },
{ 3, 0, 1, 2 } };
void
aes_encrypt(struct aes_ctx *ctx,
unsigned length, uint8_t *dst,
const uint8_t *src)
{
unsigned r, j;
uint32_t wtxt[4], t[4]; /* working ciphertext */
uint32_t e;
assert(!(length % AES_BLOCK_SIZE));
for (; length;
length -= AES_BLOCK_SIZE, src += AES_BLOCK_SIZE, dst += AES_BLOCK_SIZE)
{
key_addition_8to32(src, ctx->keys, wtxt);
for (r=1; r<ctx->nrounds; r++)
{
for (j=0; j<4; j++)
{
t[j] = dtbl[wtxt[j] & 0xff] ^
ROTRBYTE(dtbl[(wtxt[idx[1][j]] >> 8) & 0xff]^
ROTRBYTE(dtbl[(wtxt[idx[2][j]] >> 16) & 0xff] ^
ROTRBYTE(dtbl[(wtxt[idx[3][j]] >> 24) & 0xff])));
}
key_addition32(t, ctx->keys + r*4, wtxt);
}
/* last round is special: there is no mixcolumn, so we can't use the big
tables. */
for (j=0; j<4; j++)
{
e = wtxt[j] & 0xff;
e |= (wtxt[idx[1][j]]) & (0xff << 8);
e |= (wtxt[idx[2][j]]) & (0xff << 16);
e |= (wtxt[idx[3][j]]) & (0xff << 24);
t[j] = e;
}
for (j=0; j<4; j++)
t[j] = SUBBYTE(t[j], sbox);
key_addition32to8(t, ctx->keys + 4*ctx->nrounds, dst);
}
}
static const unsigned iidx[4][4] = {
{ 0, 1, 2, 3 },
{ 3, 0, 1, 2 },
{ 2, 3, 0, 1 },
{ 1, 2, 3, 0 } };
void
aes_decrypt(struct aes_ctx *ctx,
unsigned length, uint8_t *dst,
const uint8_t *src)
{
unsigned r, j;
uint32_t wtxt[4], t[4]; /* working ciphertext */
uint32_t e;
assert(!(length % AES_BLOCK_SIZE));
for (; length;
length -= AES_BLOCK_SIZE, src += AES_BLOCK_SIZE, dst += AES_BLOCK_SIZE)
{
key_addition_8to32(src, ctx->ikeys + 4*ctx->nrounds, wtxt);
for (r=ctx->nrounds-1; r> 0; r--)
{
for (j=0; j<4; j++)
{
t[j] = itbl[wtxt[j] & 0xff] ^
ROTRBYTE(itbl[(wtxt[iidx[1][j]] >> 8) & 0xff]^
ROTRBYTE(itbl[(wtxt[iidx[2][j]] >> 16) & 0xff] ^
ROTRBYTE(itbl[(wtxt[iidx[3][j]] >> 24) & 0xff])));
}
key_addition32(t, ctx->ikeys + r*4, wtxt);
}
/* last round is special: there is no mixcolumn, so we can't use the big
tables. */
for (j=0; j<4; j++)
{
e = wtxt[j] & 0xff;
e |= (wtxt[iidx[1][j]]) & (0xff << 8);
e |= (wtxt[iidx[2][j]]) & (0xff << 16);
e |= (wtxt[iidx[3][j]]) & (0xff << 24);
t[j] = e;
}
for (j=0; j<4; j++)
t[j] = SUBBYTE(t[j], isbox);
key_addition32to8(t, ctx->ikeys, dst);
}
}