| /* |
| --------------------------------------------------------------------------- |
| Copyright (c) 1998-2008, Brian Gladman, Worcester, UK. All rights reserved. |
| |
| LICENSE TERMS |
| |
| The redistribution and use of this software (with or without changes) |
| is allowed without the payment of fees or royalties provided that: |
| |
| 1. source code distributions include the above copyright notice, this |
| list of conditions and the following disclaimer; |
| |
| 2. binary distributions include the above copyright notice, this list |
| of conditions and the following disclaimer in their documentation; |
| |
| 3. the name of the copyright holder is not used to endorse products |
| built using this software without specific written permission. |
| |
| DISCLAIMER |
| |
| This software is provided 'as is' with no explicit or implied warranties |
| in respect of its properties, including, but not limited to, correctness |
| and/or fitness for purpose. |
| --------------------------------------------------------------------------- |
| Issue 09/09/2006 |
| |
| This is an AES implementation that uses only 8-bit byte operations on the |
| cipher state (there are options to use 32-bit types if available). |
| |
| The combination of mix columns and byte substitution used here is based on |
| that developed by Karl Malbrain. His contribution is acknowledged. |
| */ |
| |
| /* define if you have a fast memcpy function on your system */ |
| #if 1 |
| #define HAVE_MEMCPY |
| #include <string.h> |
| #if 0 |
| #if defined(_MSC_VER) |
| #include <intrin.h> |
| #pragma intrinsic(memcpy) |
| #endif |
| #endif |
| #endif |
| |
| #include <stdlib.h> |
| |
| /* add the target configuration to allow using internal data types and |
| * compilation options */ |
| #include "bt_target.h" |
| |
| /* define if you have fast 32-bit types on your system */ |
| #if 1 |
| #define HAVE_UINT_32T |
| #endif |
| |
| /* define if you don't want any tables */ |
| #if 1 |
| #define USE_TABLES |
| #endif |
| |
| /* On Intel Core 2 duo VERSION_1 is faster */ |
| |
| /* alternative versions (test for performance on your system) */ |
| #if 1 |
| #define VERSION_1 |
| #endif |
| |
| #include "aes.h" |
| |
| #if defined(HAVE_UINT_32T) |
| typedef uint32_t uint_32t; |
| #endif |
| |
| /* functions for finite field multiplication in the AES Galois field */ |
| |
| #define WPOLY 0x011b |
| #define BPOLY 0x1b |
| #define DPOLY 0x008d |
| |
| #define f1(x) (x) |
| #define f2(x) (((x) << 1) ^ ((((x) >> 7) & 1) * WPOLY)) |
| #define f4(x) \ |
| (((x) << 2) ^ ((((x) >> 6) & 1) * WPOLY) ^ ((((x) >> 6) & 2) * WPOLY)) |
| #define f8(x) \ |
| (((x) << 3) ^ ((((x) >> 5) & 1) * WPOLY) ^ ((((x) >> 5) & 2) * WPOLY) ^ \ |
| ((((x) >> 5) & 4) * WPOLY)) |
| #define d2(x) (((x) >> 1) ^ ((x)&1 ? DPOLY : 0)) |
| |
| #define f3(x) (f2(x) ^ (x)) |
| #define f9(x) (f8(x) ^ (x)) |
| #define fb(x) (f8(x) ^ f2(x) ^ (x)) |
| #define fd(x) (f8(x) ^ f4(x) ^ (x)) |
| #define fe(x) (f8(x) ^ f4(x) ^ f2(x)) |
| |
| #if defined(USE_TABLES) |
| |
| #define sb_data(w) \ |
| { /* S Box data values */ \ |
| w(0x63), w(0x7c), w(0x77), w(0x7b), w(0xf2), w(0x6b), w(0x6f), w(0xc5), \ |
| w(0x30), w(0x01), w(0x67), w(0x2b), w(0xfe), w(0xd7), w(0xab), \ |
| w(0x76), w(0xca), w(0x82), w(0xc9), w(0x7d), w(0xfa), w(0x59), \ |
| w(0x47), w(0xf0), w(0xad), w(0xd4), w(0xa2), w(0xaf), w(0x9c), \ |
| w(0xa4), w(0x72), w(0xc0), w(0xb7), w(0xfd), w(0x93), w(0x26), \ |
| w(0x36), w(0x3f), w(0xf7), w(0xcc), w(0x34), w(0xa5), w(0xe5), \ |
| w(0xf1), w(0x71), w(0xd8), w(0x31), w(0x15), w(0x04), w(0xc7), \ |
| w(0x23), w(0xc3), w(0x18), w(0x96), w(0x05), w(0x9a), w(0x07), \ |
| w(0x12), w(0x80), w(0xe2), w(0xeb), w(0x27), w(0xb2), w(0x75), \ |
| w(0x09), w(0x83), w(0x2c), w(0x1a), w(0x1b), w(0x6e), w(0x5a), \ |
| w(0xa0), w(0x52), w(0x3b), w(0xd6), w(0xb3), w(0x29), w(0xe3), \ |
| w(0x2f), w(0x84), w(0x53), w(0xd1), w(0x00), w(0xed), w(0x20), \ |
| w(0xfc), w(0xb1), w(0x5b), w(0x6a), w(0xcb), w(0xbe), w(0x39), \ |
| w(0x4a), w(0x4c), w(0x58), w(0xcf), w(0xd0), w(0xef), w(0xaa), \ |
| w(0xfb), w(0x43), w(0x4d), w(0x33), w(0x85), w(0x45), w(0xf9), \ |
| w(0x02), w(0x7f), w(0x50), w(0x3c), w(0x9f), w(0xa8), w(0x51), \ |
| w(0xa3), w(0x40), w(0x8f), w(0x92), w(0x9d), w(0x38), w(0xf5), \ |
| w(0xbc), w(0xb6), w(0xda), w(0x21), w(0x10), w(0xff), w(0xf3), \ |
| w(0xd2), w(0xcd), w(0x0c), w(0x13), w(0xec), w(0x5f), w(0x97), \ |
| w(0x44), w(0x17), w(0xc4), w(0xa7), w(0x7e), w(0x3d), w(0x64), \ |
| w(0x5d), w(0x19), w(0x73), w(0x60), w(0x81), w(0x4f), w(0xdc), \ |
| w(0x22), w(0x2a), w(0x90), w(0x88), w(0x46), w(0xee), w(0xb8), \ |
| w(0x14), w(0xde), w(0x5e), w(0x0b), w(0xdb), w(0xe0), w(0x32), \ |
| w(0x3a), w(0x0a), w(0x49), w(0x06), w(0x24), w(0x5c), w(0xc2), \ |
| w(0xd3), w(0xac), w(0x62), w(0x91), w(0x95), w(0xe4), w(0x79), \ |
| w(0xe7), w(0xc8), w(0x37), w(0x6d), w(0x8d), w(0xd5), w(0x4e), \ |
| w(0xa9), w(0x6c), w(0x56), w(0xf4), w(0xea), w(0x65), w(0x7a), \ |
| w(0xae), w(0x08), w(0xba), w(0x78), w(0x25), w(0x2e), w(0x1c), \ |
| w(0xa6), w(0xb4), w(0xc6), w(0xe8), w(0xdd), w(0x74), w(0x1f), \ |
| w(0x4b), w(0xbd), w(0x8b), w(0x8a), w(0x70), w(0x3e), w(0xb5), \ |
| w(0x66), w(0x48), w(0x03), w(0xf6), w(0x0e), w(0x61), w(0x35), \ |
| w(0x57), w(0xb9), w(0x86), w(0xc1), w(0x1d), w(0x9e), w(0xe1), \ |
| w(0xf8), w(0x98), w(0x11), w(0x69), w(0xd9), w(0x8e), w(0x94), \ |
| w(0x9b), w(0x1e), w(0x87), w(0xe9), w(0xce), w(0x55), w(0x28), \ |
| w(0xdf), w(0x8c), w(0xa1), w(0x89), w(0x0d), w(0xbf), w(0xe6), \ |
| w(0x42), w(0x68), w(0x41), w(0x99), w(0x2d), w(0x0f), w(0xb0), \ |
| w(0x54), w(0xbb), w(0x16) \ |
| } |
| |
| #define isb_data(w) \ |
| { /* inverse S Box data values */ \ |
| w(0x52), w(0x09), w(0x6a), w(0xd5), w(0x30), w(0x36), w(0xa5), w(0x38), \ |
| w(0xbf), w(0x40), w(0xa3), w(0x9e), w(0x81), w(0xf3), w(0xd7), \ |
| w(0xfb), w(0x7c), w(0xe3), w(0x39), w(0x82), w(0x9b), w(0x2f), \ |
| w(0xff), w(0x87), w(0x34), w(0x8e), w(0x43), w(0x44), w(0xc4), \ |
| w(0xde), w(0xe9), w(0xcb), w(0x54), w(0x7b), w(0x94), w(0x32), \ |
| w(0xa6), w(0xc2), w(0x23), w(0x3d), w(0xee), w(0x4c), w(0x95), \ |
| w(0x0b), w(0x42), w(0xfa), w(0xc3), w(0x4e), w(0x08), w(0x2e), \ |
| w(0xa1), w(0x66), w(0x28), w(0xd9), w(0x24), w(0xb2), w(0x76), \ |
| w(0x5b), w(0xa2), w(0x49), w(0x6d), w(0x8b), w(0xd1), w(0x25), \ |
| w(0x72), w(0xf8), w(0xf6), w(0x64), w(0x86), w(0x68), w(0x98), \ |
| w(0x16), w(0xd4), w(0xa4), w(0x5c), w(0xcc), w(0x5d), w(0x65), \ |
| w(0xb6), w(0x92), w(0x6c), w(0x70), w(0x48), w(0x50), w(0xfd), \ |
| w(0xed), w(0xb9), w(0xda), w(0x5e), w(0x15), w(0x46), w(0x57), \ |
| w(0xa7), w(0x8d), w(0x9d), w(0x84), w(0x90), w(0xd8), w(0xab), \ |
| w(0x00), w(0x8c), w(0xbc), w(0xd3), w(0x0a), w(0xf7), w(0xe4), \ |
| w(0x58), w(0x05), w(0xb8), w(0xb3), w(0x45), w(0x06), w(0xd0), \ |
| w(0x2c), w(0x1e), w(0x8f), w(0xca), w(0x3f), w(0x0f), w(0x02), \ |
| w(0xc1), w(0xaf), w(0xbd), w(0x03), w(0x01), w(0x13), w(0x8a), \ |
| w(0x6b), w(0x3a), w(0x91), w(0x11), w(0x41), w(0x4f), w(0x67), \ |
| w(0xdc), w(0xea), w(0x97), w(0xf2), w(0xcf), w(0xce), w(0xf0), \ |
| w(0xb4), w(0xe6), w(0x73), w(0x96), w(0xac), w(0x74), w(0x22), \ |
| w(0xe7), w(0xad), w(0x35), w(0x85), w(0xe2), w(0xf9), w(0x37), \ |
| w(0xe8), w(0x1c), w(0x75), w(0xdf), w(0x6e), w(0x47), w(0xf1), \ |
| w(0x1a), w(0x71), w(0x1d), w(0x29), w(0xc5), w(0x89), w(0x6f), \ |
| w(0xb7), w(0x62), w(0x0e), w(0xaa), w(0x18), w(0xbe), w(0x1b), \ |
| w(0xfc), w(0x56), w(0x3e), w(0x4b), w(0xc6), w(0xd2), w(0x79), \ |
| w(0x20), w(0x9a), w(0xdb), w(0xc0), w(0xfe), w(0x78), w(0xcd), \ |
| w(0x5a), w(0xf4), w(0x1f), w(0xdd), w(0xa8), w(0x33), w(0x88), \ |
| w(0x07), w(0xc7), w(0x31), w(0xb1), w(0x12), w(0x10), w(0x59), \ |
| w(0x27), w(0x80), w(0xec), w(0x5f), w(0x60), w(0x51), w(0x7f), \ |
| w(0xa9), w(0x19), w(0xb5), w(0x4a), w(0x0d), w(0x2d), w(0xe5), \ |
| w(0x7a), w(0x9f), w(0x93), w(0xc9), w(0x9c), w(0xef), w(0xa0), \ |
| w(0xe0), w(0x3b), w(0x4d), w(0xae), w(0x2a), w(0xf5), w(0xb0), \ |
| w(0xc8), w(0xeb), w(0xbb), w(0x3c), w(0x83), w(0x53), w(0x99), \ |
| w(0x61), w(0x17), w(0x2b), w(0x04), w(0x7e), w(0xba), w(0x77), \ |
| w(0xd6), w(0x26), w(0xe1), w(0x69), w(0x14), w(0x63), w(0x55), \ |
| w(0x21), w(0x0c), w(0x7d) \ |
| } |
| |
| #define mm_data(w) \ |
| { /* basic data for forming finite field tables */ \ |
| w(0x00), w(0x01), w(0x02), w(0x03), w(0x04), w(0x05), w(0x06), w(0x07), \ |
| w(0x08), w(0x09), w(0x0a), w(0x0b), w(0x0c), w(0x0d), w(0x0e), \ |
| w(0x0f), w(0x10), w(0x11), w(0x12), w(0x13), w(0x14), w(0x15), \ |
| w(0x16), w(0x17), w(0x18), w(0x19), w(0x1a), w(0x1b), w(0x1c), \ |
| w(0x1d), w(0x1e), w(0x1f), w(0x20), w(0x21), w(0x22), w(0x23), \ |
| w(0x24), w(0x25), w(0x26), w(0x27), w(0x28), w(0x29), w(0x2a), \ |
| w(0x2b), w(0x2c), w(0x2d), w(0x2e), w(0x2f), w(0x30), w(0x31), \ |
| w(0x32), w(0x33), w(0x34), w(0x35), w(0x36), w(0x37), w(0x38), \ |
| w(0x39), w(0x3a), w(0x3b), w(0x3c), w(0x3d), w(0x3e), w(0x3f), \ |
| w(0x40), w(0x41), w(0x42), w(0x43), w(0x44), w(0x45), w(0x46), \ |
| w(0x47), w(0x48), w(0x49), w(0x4a), w(0x4b), w(0x4c), w(0x4d), \ |
| w(0x4e), w(0x4f), w(0x50), w(0x51), w(0x52), w(0x53), w(0x54), \ |
| w(0x55), w(0x56), w(0x57), w(0x58), w(0x59), w(0x5a), w(0x5b), \ |
| w(0x5c), w(0x5d), w(0x5e), w(0x5f), w(0x60), w(0x61), w(0x62), \ |
| w(0x63), w(0x64), w(0x65), w(0x66), w(0x67), w(0x68), w(0x69), \ |
| w(0x6a), w(0x6b), w(0x6c), w(0x6d), w(0x6e), w(0x6f), w(0x70), \ |
| w(0x71), w(0x72), w(0x73), w(0x74), w(0x75), w(0x76), w(0x77), \ |
| w(0x78), w(0x79), w(0x7a), w(0x7b), w(0x7c), w(0x7d), w(0x7e), \ |
| w(0x7f), w(0x80), w(0x81), w(0x82), w(0x83), w(0x84), w(0x85), \ |
| w(0x86), w(0x87), w(0x88), w(0x89), w(0x8a), w(0x8b), w(0x8c), \ |
| w(0x8d), w(0x8e), w(0x8f), w(0x90), w(0x91), w(0x92), w(0x93), \ |
| w(0x94), w(0x95), w(0x96), w(0x97), w(0x98), w(0x99), w(0x9a), \ |
| w(0x9b), w(0x9c), w(0x9d), w(0x9e), w(0x9f), w(0xa0), w(0xa1), \ |
| w(0xa2), w(0xa3), w(0xa4), w(0xa5), w(0xa6), w(0xa7), w(0xa8), \ |
| w(0xa9), w(0xaa), w(0xab), w(0xac), w(0xad), w(0xae), w(0xaf), \ |
| w(0xb0), w(0xb1), w(0xb2), w(0xb3), w(0xb4), w(0xb5), w(0xb6), \ |
| w(0xb7), w(0xb8), w(0xb9), w(0xba), w(0xbb), w(0xbc), w(0xbd), \ |
| w(0xbe), w(0xbf), w(0xc0), w(0xc1), w(0xc2), w(0xc3), w(0xc4), \ |
| w(0xc5), w(0xc6), w(0xc7), w(0xc8), w(0xc9), w(0xca), w(0xcb), \ |
| w(0xcc), w(0xcd), w(0xce), w(0xcf), w(0xd0), w(0xd1), w(0xd2), \ |
| w(0xd3), w(0xd4), w(0xd5), w(0xd6), w(0xd7), w(0xd8), w(0xd9), \ |
| w(0xda), w(0xdb), w(0xdc), w(0xdd), w(0xde), w(0xdf), w(0xe0), \ |
| w(0xe1), w(0xe2), w(0xe3), w(0xe4), w(0xe5), w(0xe6), w(0xe7), \ |
| w(0xe8), w(0xe9), w(0xea), w(0xeb), w(0xec), w(0xed), w(0xee), \ |
| w(0xef), w(0xf0), w(0xf1), w(0xf2), w(0xf3), w(0xf4), w(0xf5), \ |
| w(0xf6), w(0xf7), w(0xf8), w(0xf9), w(0xfa), w(0xfb), w(0xfc), \ |
| w(0xfd), w(0xfe), w(0xff) \ |
| } |
| |
| static const uint_8t sbox[256] = sb_data(f1); |
| static const uint_8t isbox[256] = isb_data(f1); |
| |
| static const uint_8t gfm2_sbox[256] = sb_data(f2); |
| static const uint_8t gfm3_sbox[256] = sb_data(f3); |
| |
| static const uint_8t gfmul_9[256] = mm_data(f9); |
| static const uint_8t gfmul_b[256] = mm_data(fb); |
| static const uint_8t gfmul_d[256] = mm_data(fd); |
| static const uint_8t gfmul_e[256] = mm_data(fe); |
| |
| #define s_box(x) sbox[(x)] |
| #define is_box(x) isbox[(x)] |
| #define gfm2_sb(x) gfm2_sbox[(x)] |
| #define gfm3_sb(x) gfm3_sbox[(x)] |
| #define gfm_9(x) gfmul_9[(x)] |
| #define gfm_b(x) gfmul_b[(x)] |
| #define gfm_d(x) gfmul_d[(x)] |
| #define gfm_e(x) gfmul_e[(x)] |
| |
| #else |
| |
| /* this is the high bit of x right shifted by 1 */ |
| /* position. Since the starting polynomial has */ |
| /* 9 bits (0x11b), this right shift keeps the */ |
| /* values of all top bits within a byte */ |
| |
| static uint_8t hibit(const uint_8t x) { |
| uint_8t r = (uint_8t)((x >> 1) | (x >> 2)); |
| |
| r |= (r >> 2); |
| r |= (r >> 4); |
| return (r + 1) >> 1; |
| } |
| |
| /* return the inverse of the finite field element x */ |
| |
| static uint_8t gf_inv(const uint_8t x) { |
| uint_8t p1 = x, p2 = BPOLY, n1 = hibit(x), n2 = 0x80, v1 = 1, v2 = 0; |
| |
| if (x < 2) return x; |
| |
| for (;;) { |
| if (n1) |
| while (n2 >= n1) /* divide polynomial p2 by p1 */ |
| { |
| n2 /= n1; /* shift smaller polynomial left */ |
| p2 ^= (p1 * n2) & 0xff; /* and remove from larger one */ |
| v2 ^= (v1 * n2); /* shift accumulated value and */ |
| n2 = hibit(p2); /* add into result */ |
| } |
| else |
| return v1; |
| |
| if (n2) /* repeat with values swapped */ |
| while (n1 >= n2) { |
| n1 /= n2; |
| p1 ^= p2 * n1; |
| v1 ^= v2 * n1; |
| n1 = hibit(p1); |
| } |
| else |
| return v2; |
| } |
| } |
| |
| /* The forward and inverse affine transformations used in the S-box */ |
| uint_8t fwd_affine(const uint_8t x) { |
| #if defined(HAVE_UINT_32T) |
| uint_32t w = x; |
| w ^= (w << 1) ^ (w << 2) ^ (w << 3) ^ (w << 4); |
| return 0x63 ^ ((w ^ (w >> 8)) & 0xff); |
| #else |
| return 0x63 ^ x ^ (x << 1) ^ (x << 2) ^ (x << 3) ^ (x << 4) ^ (x >> 7) ^ |
| (x >> 6) ^ (x >> 5) ^ (x >> 4); |
| #endif |
| } |
| |
| uint_8t inv_affine(const uint_8t x) { |
| #if defined(HAVE_UINT_32T) |
| uint_32t w = x; |
| w = (w << 1) ^ (w << 3) ^ (w << 6); |
| return 0x05 ^ ((w ^ (w >> 8)) & 0xff); |
| #else |
| return 0x05 ^ (x << 1) ^ (x << 3) ^ (x << 6) ^ (x >> 7) ^ (x >> 5) ^ (x >> 2); |
| #endif |
| } |
| |
| #define s_box(x) fwd_affine(gf_inv(x)) |
| #define is_box(x) gf_inv(inv_affine(x)) |
| #define gfm2_sb(x) f2(s_box(x)) |
| #define gfm3_sb(x) f3(s_box(x)) |
| #define gfm_9(x) f9(x) |
| #define gfm_b(x) fb(x) |
| #define gfm_d(x) fd(x) |
| #define gfm_e(x) fe(x) |
| |
| #endif |
| |
| #if defined(HAVE_MEMCPY) |
| #define block_copy_nn(d, s, l) memcpy(d, s, l) |
| #define block_copy(d, s) memcpy(d, s, N_BLOCK) |
| #else |
| #define block_copy_nn(d, s, l) copy_block_nn(d, s, l) |
| #define block_copy(d, s) copy_block(d, s) |
| #endif |
| |
| #if !defined(HAVE_MEMCPY) |
| static void copy_block(void* d, const void* s) { |
| #if defined(HAVE_UINT_32T) |
| ((uint_32t*)d)[0] = ((uint_32t*)s)[0]; |
| ((uint_32t*)d)[1] = ((uint_32t*)s)[1]; |
| ((uint_32t*)d)[2] = ((uint_32t*)s)[2]; |
| ((uint_32t*)d)[3] = ((uint_32t*)s)[3]; |
| #else |
| ((uint_8t*)d)[0] = ((uint_8t*)s)[0]; |
| ((uint_8t*)d)[1] = ((uint_8t*)s)[1]; |
| ((uint_8t*)d)[2] = ((uint_8t*)s)[2]; |
| ((uint_8t*)d)[3] = ((uint_8t*)s)[3]; |
| ((uint_8t*)d)[4] = ((uint_8t*)s)[4]; |
| ((uint_8t*)d)[5] = ((uint_8t*)s)[5]; |
| ((uint_8t*)d)[6] = ((uint_8t*)s)[6]; |
| ((uint_8t*)d)[7] = ((uint_8t*)s)[7]; |
| ((uint_8t*)d)[8] = ((uint_8t*)s)[8]; |
| ((uint_8t*)d)[9] = ((uint_8t*)s)[9]; |
| ((uint_8t*)d)[10] = ((uint_8t*)s)[10]; |
| ((uint_8t*)d)[11] = ((uint_8t*)s)[11]; |
| ((uint_8t*)d)[12] = ((uint_8t*)s)[12]; |
| ((uint_8t*)d)[13] = ((uint_8t*)s)[13]; |
| ((uint_8t*)d)[14] = ((uint_8t*)s)[14]; |
| ((uint_8t*)d)[15] = ((uint_8t*)s)[15]; |
| #endif |
| } |
| |
| static void copy_block_nn(void* d, const void* s, uint_8t nn) { |
| while (nn--) *((uint_8t*)d)++ = *((uint_8t*)s)++; |
| } |
| #endif |
| |
| static void xor_block(void* d, const void* s) { |
| #if defined(HAVE_UINT_32T) |
| ((uint_32t*)d)[0] ^= ((uint_32t*)s)[0]; |
| ((uint_32t*)d)[1] ^= ((uint_32t*)s)[1]; |
| ((uint_32t*)d)[2] ^= ((uint_32t*)s)[2]; |
| ((uint_32t*)d)[3] ^= ((uint_32t*)s)[3]; |
| #else |
| ((uint_8t*)d)[0] ^= ((uint_8t*)s)[0]; |
| ((uint_8t*)d)[1] ^= ((uint_8t*)s)[1]; |
| ((uint_8t*)d)[2] ^= ((uint_8t*)s)[2]; |
| ((uint_8t*)d)[3] ^= ((uint_8t*)s)[3]; |
| ((uint_8t*)d)[4] ^= ((uint_8t*)s)[4]; |
| ((uint_8t*)d)[5] ^= ((uint_8t*)s)[5]; |
| ((uint_8t*)d)[6] ^= ((uint_8t*)s)[6]; |
| ((uint_8t*)d)[7] ^= ((uint_8t*)s)[7]; |
| ((uint_8t*)d)[8] ^= ((uint_8t*)s)[8]; |
| ((uint_8t*)d)[9] ^= ((uint_8t*)s)[9]; |
| ((uint_8t*)d)[10] ^= ((uint_8t*)s)[10]; |
| ((uint_8t*)d)[11] ^= ((uint_8t*)s)[11]; |
| ((uint_8t*)d)[12] ^= ((uint_8t*)s)[12]; |
| ((uint_8t*)d)[13] ^= ((uint_8t*)s)[13]; |
| ((uint_8t*)d)[14] ^= ((uint_8t*)s)[14]; |
| ((uint_8t*)d)[15] ^= ((uint_8t*)s)[15]; |
| #endif |
| } |
| |
| static void copy_and_key(void* d, const void* s, const void* k) { |
| #if defined(HAVE_UINT_32T) |
| ((uint_32t*)d)[0] = ((uint_32t*)s)[0] ^ ((uint_32t*)k)[0]; |
| ((uint_32t*)d)[1] = ((uint_32t*)s)[1] ^ ((uint_32t*)k)[1]; |
| ((uint_32t*)d)[2] = ((uint_32t*)s)[2] ^ ((uint_32t*)k)[2]; |
| ((uint_32t*)d)[3] = ((uint_32t*)s)[3] ^ ((uint_32t*)k)[3]; |
| #elif 1 |
| ((uint_8t*)d)[0] = ((uint_8t*)s)[0] ^ ((uint_8t*)k)[0]; |
| ((uint_8t*)d)[1] = ((uint_8t*)s)[1] ^ ((uint_8t*)k)[1]; |
| ((uint_8t*)d)[2] = ((uint_8t*)s)[2] ^ ((uint_8t*)k)[2]; |
| ((uint_8t*)d)[3] = ((uint_8t*)s)[3] ^ ((uint_8t*)k)[3]; |
| ((uint_8t*)d)[4] = ((uint_8t*)s)[4] ^ ((uint_8t*)k)[4]; |
| ((uint_8t*)d)[5] = ((uint_8t*)s)[5] ^ ((uint_8t*)k)[5]; |
| ((uint_8t*)d)[6] = ((uint_8t*)s)[6] ^ ((uint_8t*)k)[6]; |
| ((uint_8t*)d)[7] = ((uint_8t*)s)[7] ^ ((uint_8t*)k)[7]; |
| ((uint_8t*)d)[8] = ((uint_8t*)s)[8] ^ ((uint_8t*)k)[8]; |
| ((uint_8t*)d)[9] = ((uint_8t*)s)[9] ^ ((uint_8t*)k)[9]; |
| ((uint_8t*)d)[10] = ((uint_8t*)s)[10] ^ ((uint_8t*)k)[10]; |
| ((uint_8t*)d)[11] = ((uint_8t*)s)[11] ^ ((uint_8t*)k)[11]; |
| ((uint_8t*)d)[12] = ((uint_8t*)s)[12] ^ ((uint_8t*)k)[12]; |
| ((uint_8t*)d)[13] = ((uint_8t*)s)[13] ^ ((uint_8t*)k)[13]; |
| ((uint_8t*)d)[14] = ((uint_8t*)s)[14] ^ ((uint_8t*)k)[14]; |
| ((uint_8t*)d)[15] = ((uint_8t*)s)[15] ^ ((uint_8t*)k)[15]; |
| #else |
| block_copy(d, s); |
| xor_block(d, k); |
| #endif |
| } |
| |
| static void add_round_key(uint_8t d[N_BLOCK], const uint_8t k[N_BLOCK]) { |
| xor_block(d, k); |
| } |
| |
| static void shift_sub_rows(uint_8t st[N_BLOCK]) { |
| uint_8t tt; |
| |
| st[0] = s_box(st[0]); |
| st[4] = s_box(st[4]); |
| st[8] = s_box(st[8]); |
| st[12] = s_box(st[12]); |
| |
| tt = st[1]; |
| st[1] = s_box(st[5]); |
| st[5] = s_box(st[9]); |
| st[9] = s_box(st[13]); |
| st[13] = s_box(tt); |
| |
| tt = st[2]; |
| st[2] = s_box(st[10]); |
| st[10] = s_box(tt); |
| tt = st[6]; |
| st[6] = s_box(st[14]); |
| st[14] = s_box(tt); |
| |
| tt = st[15]; |
| st[15] = s_box(st[11]); |
| st[11] = s_box(st[7]); |
| st[7] = s_box(st[3]); |
| st[3] = s_box(tt); |
| } |
| |
| static void inv_shift_sub_rows(uint_8t st[N_BLOCK]) { |
| uint_8t tt; |
| |
| st[0] = is_box(st[0]); |
| st[4] = is_box(st[4]); |
| st[8] = is_box(st[8]); |
| st[12] = is_box(st[12]); |
| |
| tt = st[13]; |
| st[13] = is_box(st[9]); |
| st[9] = is_box(st[5]); |
| st[5] = is_box(st[1]); |
| st[1] = is_box(tt); |
| |
| tt = st[2]; |
| st[2] = is_box(st[10]); |
| st[10] = is_box(tt); |
| tt = st[6]; |
| st[6] = is_box(st[14]); |
| st[14] = is_box(tt); |
| |
| tt = st[3]; |
| st[3] = is_box(st[7]); |
| st[7] = is_box(st[11]); |
| st[11] = is_box(st[15]); |
| st[15] = is_box(tt); |
| } |
| |
| #if defined(VERSION_1) |
| static void mix_sub_columns(uint_8t dt[N_BLOCK]) { |
| uint_8t st[N_BLOCK]; |
| block_copy(st, dt); |
| #else |
| static void mix_sub_columns(uint_8t dt[N_BLOCK], uint_8t st[N_BLOCK]) { |
| #endif |
| dt[0] = gfm2_sb(st[0]) ^ gfm3_sb(st[5]) ^ s_box(st[10]) ^ s_box(st[15]); |
| dt[1] = s_box(st[0]) ^ gfm2_sb(st[5]) ^ gfm3_sb(st[10]) ^ s_box(st[15]); |
| dt[2] = s_box(st[0]) ^ s_box(st[5]) ^ gfm2_sb(st[10]) ^ gfm3_sb(st[15]); |
| dt[3] = gfm3_sb(st[0]) ^ s_box(st[5]) ^ s_box(st[10]) ^ gfm2_sb(st[15]); |
| |
| dt[4] = gfm2_sb(st[4]) ^ gfm3_sb(st[9]) ^ s_box(st[14]) ^ s_box(st[3]); |
| dt[5] = s_box(st[4]) ^ gfm2_sb(st[9]) ^ gfm3_sb(st[14]) ^ s_box(st[3]); |
| dt[6] = s_box(st[4]) ^ s_box(st[9]) ^ gfm2_sb(st[14]) ^ gfm3_sb(st[3]); |
| dt[7] = gfm3_sb(st[4]) ^ s_box(st[9]) ^ s_box(st[14]) ^ gfm2_sb(st[3]); |
| |
| dt[8] = gfm2_sb(st[8]) ^ gfm3_sb(st[13]) ^ s_box(st[2]) ^ s_box(st[7]); |
| dt[9] = s_box(st[8]) ^ gfm2_sb(st[13]) ^ gfm3_sb(st[2]) ^ s_box(st[7]); |
| dt[10] = s_box(st[8]) ^ s_box(st[13]) ^ gfm2_sb(st[2]) ^ gfm3_sb(st[7]); |
| dt[11] = gfm3_sb(st[8]) ^ s_box(st[13]) ^ s_box(st[2]) ^ gfm2_sb(st[7]); |
| |
| dt[12] = gfm2_sb(st[12]) ^ gfm3_sb(st[1]) ^ s_box(st[6]) ^ s_box(st[11]); |
| dt[13] = s_box(st[12]) ^ gfm2_sb(st[1]) ^ gfm3_sb(st[6]) ^ s_box(st[11]); |
| dt[14] = s_box(st[12]) ^ s_box(st[1]) ^ gfm2_sb(st[6]) ^ gfm3_sb(st[11]); |
| dt[15] = gfm3_sb(st[12]) ^ s_box(st[1]) ^ s_box(st[6]) ^ gfm2_sb(st[11]); |
| } |
| |
| #if defined(VERSION_1) |
| static void inv_mix_sub_columns(uint_8t dt[N_BLOCK]) { |
| uint_8t st[N_BLOCK]; |
| block_copy(st, dt); |
| #else |
| static void inv_mix_sub_columns(uint_8t dt[N_BLOCK], uint_8t st[N_BLOCK]) { |
| #endif |
| dt[0] = is_box(gfm_e(st[0]) ^ gfm_b(st[1]) ^ gfm_d(st[2]) ^ gfm_9(st[3])); |
| dt[5] = is_box(gfm_9(st[0]) ^ gfm_e(st[1]) ^ gfm_b(st[2]) ^ gfm_d(st[3])); |
| dt[10] = is_box(gfm_d(st[0]) ^ gfm_9(st[1]) ^ gfm_e(st[2]) ^ gfm_b(st[3])); |
| dt[15] = is_box(gfm_b(st[0]) ^ gfm_d(st[1]) ^ gfm_9(st[2]) ^ gfm_e(st[3])); |
| |
| dt[4] = is_box(gfm_e(st[4]) ^ gfm_b(st[5]) ^ gfm_d(st[6]) ^ gfm_9(st[7])); |
| dt[9] = is_box(gfm_9(st[4]) ^ gfm_e(st[5]) ^ gfm_b(st[6]) ^ gfm_d(st[7])); |
| dt[14] = is_box(gfm_d(st[4]) ^ gfm_9(st[5]) ^ gfm_e(st[6]) ^ gfm_b(st[7])); |
| dt[3] = is_box(gfm_b(st[4]) ^ gfm_d(st[5]) ^ gfm_9(st[6]) ^ gfm_e(st[7])); |
| |
| dt[8] = is_box(gfm_e(st[8]) ^ gfm_b(st[9]) ^ gfm_d(st[10]) ^ gfm_9(st[11])); |
| dt[13] = is_box(gfm_9(st[8]) ^ gfm_e(st[9]) ^ gfm_b(st[10]) ^ gfm_d(st[11])); |
| dt[2] = is_box(gfm_d(st[8]) ^ gfm_9(st[9]) ^ gfm_e(st[10]) ^ gfm_b(st[11])); |
| dt[7] = is_box(gfm_b(st[8]) ^ gfm_d(st[9]) ^ gfm_9(st[10]) ^ gfm_e(st[11])); |
| |
| dt[12] = |
| is_box(gfm_e(st[12]) ^ gfm_b(st[13]) ^ gfm_d(st[14]) ^ gfm_9(st[15])); |
| dt[1] = is_box(gfm_9(st[12]) ^ gfm_e(st[13]) ^ gfm_b(st[14]) ^ gfm_d(st[15])); |
| dt[6] = is_box(gfm_d(st[12]) ^ gfm_9(st[13]) ^ gfm_e(st[14]) ^ gfm_b(st[15])); |
| dt[11] = |
| is_box(gfm_b(st[12]) ^ gfm_d(st[13]) ^ gfm_9(st[14]) ^ gfm_e(st[15])); |
| } |
| |
| #if defined(AES_ENC_PREKEYED) || defined(AES_DEC_PREKEYED) |
| |
| /* Set the cipher key for the pre-keyed version */ |
| /* NOTE: If the length_type used for the key length is an |
| unsigned 8-bit character, a key length of 256 bits must |
| be entered as a length in bytes (valid inputs are hence |
| 128, 192, 16, 24 and 32). |
| */ |
| |
| return_type aes_set_key(const unsigned char key[], length_type keylen, |
| aes_context ctx[1]) { |
| uint_8t cc, rc, hi; |
| |
| switch (keylen) { |
| case 16: |
| case 128: /* length in bits (128 = 8*16) */ |
| keylen = 16; |
| break; |
| case 24: |
| case 192: /* length in bits (192 = 8*24) */ |
| keylen = 24; |
| break; |
| case 32: |
| /* case 256: length in bits (256 = 8*32) */ |
| keylen = 32; |
| break; |
| default: |
| ctx->rnd = 0; |
| return (return_type)-1; |
| } |
| block_copy_nn(ctx->ksch, key, keylen); |
| hi = (keylen + 28) << 2; |
| ctx->rnd = (hi >> 4) - 1; |
| for (cc = keylen, rc = 1; cc < hi; cc += 4) { |
| uint_8t tt, t0, t1, t2, t3; |
| |
| t0 = ctx->ksch[cc - 4]; |
| t1 = ctx->ksch[cc - 3]; |
| t2 = ctx->ksch[cc - 2]; |
| t3 = ctx->ksch[cc - 1]; |
| if (cc % keylen == 0) { |
| tt = t0; |
| t0 = s_box(t1) ^ rc; |
| t1 = s_box(t2); |
| t2 = s_box(t3); |
| t3 = s_box(tt); |
| rc = f2(rc); |
| } else if (keylen > 24 && cc % keylen == 16) { |
| t0 = s_box(t0); |
| t1 = s_box(t1); |
| t2 = s_box(t2); |
| t3 = s_box(t3); |
| } |
| tt = cc - keylen; |
| ctx->ksch[cc + 0] = ctx->ksch[tt + 0] ^ t0; |
| ctx->ksch[cc + 1] = ctx->ksch[tt + 1] ^ t1; |
| ctx->ksch[cc + 2] = ctx->ksch[tt + 2] ^ t2; |
| ctx->ksch[cc + 3] = ctx->ksch[tt + 3] ^ t3; |
| } |
| return 0; |
| } |
| |
| #endif |
| |
| #if defined(AES_ENC_PREKEYED) |
| |
| /* Encrypt a single block of 16 bytes */ |
| |
| return_type aes_encrypt(const unsigned char in[N_BLOCK], |
| unsigned char out[N_BLOCK], const aes_context ctx[1]) { |
| if (ctx->rnd) { |
| uint_8t s1[N_BLOCK], r; |
| copy_and_key(s1, in, ctx->ksch); |
| |
| for (r = 1; r < ctx->rnd; ++r) |
| #if defined(VERSION_1) |
| { |
| mix_sub_columns(s1); |
| add_round_key(s1, ctx->ksch + r * N_BLOCK); |
| } |
| #else |
| { |
| uint_8t s2[N_BLOCK]; |
| mix_sub_columns(s2, s1); |
| copy_and_key(s1, s2, ctx->ksch + r * N_BLOCK); |
| } |
| #endif |
| shift_sub_rows(s1); |
| copy_and_key(out, s1, ctx->ksch + r * N_BLOCK); |
| } else |
| return (return_type)-1; |
| return 0; |
| } |
| |
| /* CBC encrypt a number of blocks (input and return an IV) */ |
| |
| return_type aes_cbc_encrypt(const unsigned char* in, unsigned char* out, |
| int n_block, unsigned char iv[N_BLOCK], |
| const aes_context ctx[1]) { |
| while (n_block--) { |
| xor_block(iv, in); |
| if (aes_encrypt(iv, iv, ctx) != EXIT_SUCCESS) return EXIT_FAILURE; |
| memcpy(out, iv, N_BLOCK); |
| in += N_BLOCK; |
| out += N_BLOCK; |
| } |
| return EXIT_SUCCESS; |
| } |
| |
| #endif |
| |
| #if defined(AES_DEC_PREKEYED) |
| |
| /* Decrypt a single block of 16 bytes */ |
| |
| return_type aes_decrypt(const unsigned char in[N_BLOCK], |
| unsigned char out[N_BLOCK], const aes_context ctx[1]) { |
| if (ctx->rnd) { |
| uint_8t s1[N_BLOCK], r; |
| copy_and_key(s1, in, ctx->ksch + ctx->rnd * N_BLOCK); |
| inv_shift_sub_rows(s1); |
| |
| for (r = ctx->rnd; --r;) |
| #if defined(VERSION_1) |
| { |
| add_round_key(s1, ctx->ksch + r * N_BLOCK); |
| inv_mix_sub_columns(s1); |
| } |
| #else |
| { |
| uint_8t s2[N_BLOCK]; |
| copy_and_key(s2, s1, ctx->ksch + r * N_BLOCK); |
| inv_mix_sub_columns(s1, s2); |
| } |
| #endif |
| copy_and_key(out, s1, ctx->ksch); |
| } else |
| return (return_type)-1; |
| return 0; |
| } |
| |
| /* CBC decrypt a number of blocks (input and return an IV) */ |
| |
| return_type aes_cbc_decrypt(const unsigned char* in, unsigned char* out, |
| int n_block, unsigned char iv[N_BLOCK], |
| const aes_context ctx[1]) { |
| while (n_block--) { |
| uint_8t tmp[N_BLOCK]; |
| |
| memcpy(tmp, in, N_BLOCK); |
| if (aes_decrypt(in, out, ctx) != EXIT_SUCCESS) return EXIT_FAILURE; |
| xor_block(out, iv); |
| memcpy(iv, tmp, N_BLOCK); |
| in += N_BLOCK; |
| out += N_BLOCK; |
| } |
| return EXIT_SUCCESS; |
| } |
| |
| #endif |
| |
| #if defined(AES_ENC_128_OTFK) |
| |
| /* The 'on the fly' encryption key update for for 128 bit keys */ |
| |
| static void update_encrypt_key_128(uint_8t k[N_BLOCK], uint_8t* rc) { |
| uint_8t cc; |
| |
| k[0] ^= s_box(k[13]) ^ *rc; |
| k[1] ^= s_box(k[14]); |
| k[2] ^= s_box(k[15]); |
| k[3] ^= s_box(k[12]); |
| *rc = f2(*rc); |
| |
| for (cc = 4; cc < 16; cc += 4) { |
| k[cc + 0] ^= k[cc - 4]; |
| k[cc + 1] ^= k[cc - 3]; |
| k[cc + 2] ^= k[cc - 2]; |
| k[cc + 3] ^= k[cc - 1]; |
| } |
| } |
| |
| /* Encrypt a single block of 16 bytes with 'on the fly' 128 bit keying */ |
| |
| void aes_encrypt_128(const unsigned char in[N_BLOCK], |
| unsigned char out[N_BLOCK], |
| const unsigned char key[N_BLOCK], |
| unsigned char o_key[N_BLOCK]) { |
| uint_8t s1[N_BLOCK], r, rc = 1; |
| |
| if (o_key != key) block_copy(o_key, key); |
| copy_and_key(s1, in, o_key); |
| |
| for (r = 1; r < 10; ++r) |
| #if defined(VERSION_1) |
| { |
| mix_sub_columns(s1); |
| update_encrypt_key_128(o_key, &rc); |
| add_round_key(s1, o_key); |
| } |
| #else |
| { |
| uint_8t s2[N_BLOCK]; |
| mix_sub_columns(s2, s1); |
| update_encrypt_key_128(o_key, &rc); |
| copy_and_key(s1, s2, o_key); |
| } |
| #endif |
| |
| shift_sub_rows(s1); |
| update_encrypt_key_128(o_key, &rc); |
| copy_and_key(out, s1, o_key); |
| } |
| |
| #endif |
| |
| #if defined(AES_DEC_128_OTFK) |
| |
| /* The 'on the fly' decryption key update for for 128 bit keys */ |
| |
| static void update_decrypt_key_128(uint_8t k[N_BLOCK], uint_8t* rc) { |
| uint_8t cc; |
| |
| for (cc = 12; cc > 0; cc -= 4) { |
| k[cc + 0] ^= k[cc - 4]; |
| k[cc + 1] ^= k[cc - 3]; |
| k[cc + 2] ^= k[cc - 2]; |
| k[cc + 3] ^= k[cc - 1]; |
| } |
| *rc = d2(*rc); |
| k[0] ^= s_box(k[13]) ^ *rc; |
| k[1] ^= s_box(k[14]); |
| k[2] ^= s_box(k[15]); |
| k[3] ^= s_box(k[12]); |
| } |
| |
| /* Decrypt a single block of 16 bytes with 'on the fly' 128 bit keying */ |
| |
| void aes_decrypt_128(const unsigned char in[N_BLOCK], |
| unsigned char out[N_BLOCK], |
| const unsigned char key[N_BLOCK], |
| unsigned char o_key[N_BLOCK]) { |
| uint_8t s1[N_BLOCK], r, rc = 0x6c; |
| if (o_key != key) block_copy(o_key, key); |
| |
| copy_and_key(s1, in, o_key); |
| inv_shift_sub_rows(s1); |
| |
| for (r = 10; --r;) |
| #if defined(VERSION_1) |
| { |
| update_decrypt_key_128(o_key, &rc); |
| add_round_key(s1, o_key); |
| inv_mix_sub_columns(s1); |
| } |
| #else |
| { |
| uint_8t s2[N_BLOCK]; |
| update_decrypt_key_128(o_key, &rc); |
| copy_and_key(s2, s1, o_key); |
| inv_mix_sub_columns(s1, s2); |
| } |
| #endif |
| update_decrypt_key_128(o_key, &rc); |
| copy_and_key(out, s1, o_key); |
| } |
| |
| #endif |
| |
| #if defined(AES_ENC_256_OTFK) |
| |
| /* The 'on the fly' encryption key update for for 256 bit keys */ |
| |
| static void update_encrypt_key_256(uint_8t k[2 * N_BLOCK], uint_8t* rc) { |
| uint_8t cc; |
| |
| k[0] ^= s_box(k[29]) ^ *rc; |
| k[1] ^= s_box(k[30]); |
| k[2] ^= s_box(k[31]); |
| k[3] ^= s_box(k[28]); |
| *rc = f2(*rc); |
| |
| for (cc = 4; cc < 16; cc += 4) { |
| k[cc + 0] ^= k[cc - 4]; |
| k[cc + 1] ^= k[cc - 3]; |
| k[cc + 2] ^= k[cc - 2]; |
| k[cc + 3] ^= k[cc - 1]; |
| } |
| |
| k[16] ^= s_box(k[12]); |
| k[17] ^= s_box(k[13]); |
| k[18] ^= s_box(k[14]); |
| k[19] ^= s_box(k[15]); |
| |
| for (cc = 20; cc < 32; cc += 4) { |
| k[cc + 0] ^= k[cc - 4]; |
| k[cc + 1] ^= k[cc - 3]; |
| k[cc + 2] ^= k[cc - 2]; |
| k[cc + 3] ^= k[cc - 1]; |
| } |
| } |
| |
| /* Encrypt a single block of 16 bytes with 'on the fly' 256 bit keying */ |
| |
| void aes_encrypt_256(const unsigned char in[N_BLOCK], |
| unsigned char out[N_BLOCK], |
| const unsigned char key[2 * N_BLOCK], |
| unsigned char o_key[2 * N_BLOCK]) { |
| uint_8t s1[N_BLOCK], r, rc = 1; |
| if (o_key != key) { |
| block_copy(o_key, key); |
| block_copy(o_key + 16, key + 16); |
| } |
| copy_and_key(s1, in, o_key); |
| |
| for (r = 1; r < 14; ++r) |
| #if defined(VERSION_1) |
| { |
| mix_sub_columns(s1); |
| if (r & 1) |
| add_round_key(s1, o_key + 16); |
| else { |
| update_encrypt_key_256(o_key, &rc); |
| add_round_key(s1, o_key); |
| } |
| } |
| #else |
| { |
| uint_8t s2[N_BLOCK]; |
| mix_sub_columns(s2, s1); |
| if (r & 1) |
| copy_and_key(s1, s2, o_key + 16); |
| else { |
| update_encrypt_key_256(o_key, &rc); |
| copy_and_key(s1, s2, o_key); |
| } |
| } |
| #endif |
| |
| shift_sub_rows(s1); |
| update_encrypt_key_256(o_key, &rc); |
| copy_and_key(out, s1, o_key); |
| } |
| |
| #endif |
| |
| #if defined(AES_DEC_256_OTFK) |
| |
| /* The 'on the fly' encryption key update for for 256 bit keys */ |
| |
| static void update_decrypt_key_256(uint_8t k[2 * N_BLOCK], uint_8t* rc) { |
| uint_8t cc; |
| |
| for (cc = 28; cc > 16; cc -= 4) { |
| k[cc + 0] ^= k[cc - 4]; |
| k[cc + 1] ^= k[cc - 3]; |
| k[cc + 2] ^= k[cc - 2]; |
| k[cc + 3] ^= k[cc - 1]; |
| } |
| |
| k[16] ^= s_box(k[12]); |
| k[17] ^= s_box(k[13]); |
| k[18] ^= s_box(k[14]); |
| k[19] ^= s_box(k[15]); |
| |
| for (cc = 12; cc > 0; cc -= 4) { |
| k[cc + 0] ^= k[cc - 4]; |
| k[cc + 1] ^= k[cc - 3]; |
| k[cc + 2] ^= k[cc - 2]; |
| k[cc + 3] ^= k[cc - 1]; |
| } |
| |
| *rc = d2(*rc); |
| k[0] ^= s_box(k[29]) ^ *rc; |
| k[1] ^= s_box(k[30]); |
| k[2] ^= s_box(k[31]); |
| k[3] ^= s_box(k[28]); |
| } |
| |
| /* Decrypt a single block of 16 bytes with 'on the fly' |
| 256 bit keying |
| */ |
| void aes_decrypt_256(const unsigned char in[N_BLOCK], |
| unsigned char out[N_BLOCK], |
| const unsigned char key[2 * N_BLOCK], |
| unsigned char o_key[2 * N_BLOCK]) { |
| uint_8t s1[N_BLOCK], r, rc = 0x80; |
| |
| if (o_key != key) { |
| block_copy(o_key, key); |
| block_copy(o_key + 16, key + 16); |
| } |
| |
| copy_and_key(s1, in, o_key); |
| inv_shift_sub_rows(s1); |
| |
| for (r = 14; --r;) |
| #if defined(VERSION_1) |
| { |
| if ((r & 1)) { |
| update_decrypt_key_256(o_key, &rc); |
| add_round_key(s1, o_key + 16); |
| } else |
| add_round_key(s1, o_key); |
| inv_mix_sub_columns(s1); |
| } |
| #else |
| { |
| uint_8t s2[N_BLOCK]; |
| if ((r & 1)) { |
| update_decrypt_key_256(o_key, &rc); |
| copy_and_key(s2, s1, o_key + 16); |
| } else |
| copy_and_key(s2, s1, o_key); |
| inv_mix_sub_columns(s1, s2); |
| } |
| #endif |
| copy_and_key(out, s1, o_key); |
| } |
| |
| #endif |
