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Diffstat (limited to 'arch/x86_64/crypto/aes.c')
| -rw-r--r-- | arch/x86_64/crypto/aes.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/arch/x86_64/crypto/aes.c b/arch/x86_64/crypto/aes.c new file mode 100644 index 000000000000..2b5c4010ce38 --- /dev/null +++ b/arch/x86_64/crypto/aes.c @@ -0,0 +1,324 @@ +/* + * Cryptographic API. + * + * AES Cipher Algorithm. + * + * Based on Brian Gladman's code. + * + * Linux developers: + * Alexander Kjeldaas <astor@fast.no> + * Herbert Valerio Riedel <hvr@hvrlab.org> + * Kyle McMartin <kyle@debian.org> + * Adam J. Richter <adam@yggdrasil.com> (conversion to 2.5 API). + * Andreas Steinmetz <ast@domdv.de> (adapted to x86_64 assembler) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * --------------------------------------------------------------------------- + * Copyright (c) 2002, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK. + * All rights reserved. + * + * LICENSE TERMS + * + * The free distribution and use of this software in both source and binary + * form is allowed (with or without changes) provided that: + * + * 1. distributions of this source code include the above copyright + * notice, this list of conditions and the following disclaimer; + * + * 2. distributions in binary form include the above copyright + * notice, this list of conditions and the following disclaimer + * in the documentation and/or other associated materials; + * + * 3. the copyright holder's name is not used to endorse products + * built using this software without specific written permission. + * + * ALTERNATIVELY, provided that this notice is retained in full, this product + * may be distributed under the terms of the GNU General Public License (GPL), + * in which case the provisions of the GPL apply INSTEAD OF those given above. + * + * 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. + * --------------------------------------------------------------------------- + */ + +/* Some changes from the Gladman version: + s/RIJNDAEL(e_key)/E_KEY/g + s/RIJNDAEL(d_key)/D_KEY/g +*/ + +#include <asm/byteorder.h> +#include <linux/bitops.h> +#include <linux/crypto.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/types.h> + +#define AES_MIN_KEY_SIZE 16 +#define AES_MAX_KEY_SIZE 32 + +#define AES_BLOCK_SIZE 16 + +/* + * #define byte(x, nr) ((unsigned char)((x) >> (nr*8))) + */ +static inline u8 byte(const u32 x, const unsigned n) +{ + return x >> (n << 3); +} + +#define u32_in(x) le32_to_cpu(*(const __le32 *)(x)) + +struct aes_ctx +{ + u32 key_length; + u32 E[60]; + u32 D[60]; +}; + +#define E_KEY ctx->E +#define D_KEY ctx->D + +static u8 pow_tab[256] __initdata; +static u8 log_tab[256] __initdata; +static u8 sbx_tab[256] __initdata; +static u8 isb_tab[256] __initdata; +static u32 rco_tab[10]; +u32 aes_ft_tab[4][256]; +u32 aes_it_tab[4][256]; + +u32 aes_fl_tab[4][256]; +u32 aes_il_tab[4][256]; + +static inline u8 f_mult(u8 a, u8 b) +{ + u8 aa = log_tab[a], cc = aa + log_tab[b]; + + return pow_tab[cc + (cc < aa ? 1 : 0)]; +} + +#define ff_mult(a, b) (a && b ? f_mult(a, b) : 0) + +#define ls_box(x) \ + (aes_fl_tab[0][byte(x, 0)] ^ \ + aes_fl_tab[1][byte(x, 1)] ^ \ + aes_fl_tab[2][byte(x, 2)] ^ \ + aes_fl_tab[3][byte(x, 3)]) + +static void __init gen_tabs(void) +{ + u32 i, t; + u8 p, q; + + /* log and power tables for GF(2**8) finite field with + 0x011b as modular polynomial - the simplest primitive + root is 0x03, used here to generate the tables */ + + for (i = 0, p = 1; i < 256; ++i) { + pow_tab[i] = (u8)p; + log_tab[p] = (u8)i; + + p ^= (p << 1) ^ (p & 0x80 ? 0x01b : 0); + } + + log_tab[1] = 0; + + for (i = 0, p = 1; i < 10; ++i) { + rco_tab[i] = p; + + p = (p << 1) ^ (p & 0x80 ? 0x01b : 0); + } + + for (i = 0; i < 256; ++i) { + p = (i ? pow_tab[255 - log_tab[i]] : 0); + q = ((p >> 7) | (p << 1)) ^ ((p >> 6) | (p << 2)); + p ^= 0x63 ^ q ^ ((q >> 6) | (q << 2)); + sbx_tab[i] = p; + isb_tab[p] = (u8)i; + } + + for (i = 0; i < 256; ++i) { + p = sbx_tab[i]; + + t = p; + aes_fl_tab[0][i] = t; + aes_fl_tab[1][i] = rol32(t, 8); + aes_fl_tab[2][i] = rol32(t, 16); + aes_fl_tab[3][i] = rol32(t, 24); + + t = ((u32)ff_mult(2, p)) | + ((u32)p << 8) | + ((u32)p << 16) | ((u32)ff_mult(3, p) << 24); + + aes_ft_tab[0][i] = t; + aes_ft_tab[1][i] = rol32(t, 8); + aes_ft_tab[2][i] = rol32(t, 16); + aes_ft_tab[3][i] = rol32(t, 24); + + p = isb_tab[i]; + + t = p; + aes_il_tab[0][i] = t; + aes_il_tab[1][i] = rol32(t, 8); + aes_il_tab[2][i] = rol32(t, 16); + aes_il_tab[3][i] = rol32(t, 24); + + t = ((u32)ff_mult(14, p)) | + ((u32)ff_mult(9, p) << 8) | + ((u32)ff_mult(13, p) << 16) | + ((u32)ff_mult(11, p) << 24); + + aes_it_tab[0][i] = t; + aes_it_tab[1][i] = rol32(t, 8); + aes_it_tab[2][i] = rol32(t, 16); + aes_it_tab[3][i] = rol32(t, 24); + } +} + +#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b) + +#define imix_col(y, x) \ + u = star_x(x); \ + v = star_x(u); \ + w = star_x(v); \ + t = w ^ (x); \ + (y) = u ^ v ^ w; \ + (y) ^= ror32(u ^ t, 8) ^ \ + ror32(v ^ t, 16) ^ \ + ror32(t, 24) + +/* initialise the key schedule from the user supplied key */ + +#define loop4(i) \ +{ \ + t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \ + t ^= E_KEY[4 * i]; E_KEY[4 * i + 4] = t; \ + t ^= E_KEY[4 * i + 1]; E_KEY[4 * i + 5] = t; \ + t ^= E_KEY[4 * i + 2]; E_KEY[4 * i + 6] = t; \ + t ^= E_KEY[4 * i + 3]; E_KEY[4 * i + 7] = t; \ +} + +#define loop6(i) \ +{ \ + t = ror32(t, 8); t = ls_box(t) ^ rco_tab[i]; \ + t ^= E_KEY[6 * i]; E_KEY[6 * i + 6] = t; \ + t ^= E_KEY[6 * i + 1]; E_KEY[6 * i + 7] = t; \ + t ^= E_KEY[6 * i + 2]; E_KEY[6 * i + 8] = t; \ + t ^= E_KEY[6 * i + 3]; E_KEY[6 * i + 9] = t; \ + t ^= E_KEY[6 * i + 4]; E_KEY[6 * i + 10] = t; \ + t ^= E_KEY[6 * i + 5]; E_KEY[6 * i + 11] = t; \ +} + +#define loop8(i) \ +{ \ + t = ror32(t, 8); ; t = ls_box(t) ^ rco_tab[i]; \ + t ^= E_KEY[8 * i]; E_KEY[8 * i + 8] = t; \ + t ^= E_KEY[8 * i + 1]; E_KEY[8 * i + 9] = t; \ + t ^= E_KEY[8 * i + 2]; E_KEY[8 * i + 10] = t; \ + t ^= E_KEY[8 * i + 3]; E_KEY[8 * i + 11] = t; \ + t = E_KEY[8 * i + 4] ^ ls_box(t); \ + E_KEY[8 * i + 12] = t; \ + t ^= E_KEY[8 * i + 5]; E_KEY[8 * i + 13] = t; \ + t ^= E_KEY[8 * i + 6]; E_KEY[8 * i + 14] = t; \ + t ^= E_KEY[8 * i + 7]; E_KEY[8 * i + 15] = t; \ +} + +static int aes_set_key(void *ctx_arg, const u8 *in_key, unsigned int key_len, + u32 *flags) +{ + struct aes_ctx *ctx = ctx_arg; + u32 i, j, t, u, v, w; + + if (key_len != 16 && key_len != 24 && key_len != 32) { + *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + ctx->key_length = key_len; + + D_KEY[key_len + 24] = E_KEY[0] = u32_in(in_key); + D_KEY[key_len + 25] = E_KEY[1] = u32_in(in_key + 4); + D_KEY[key_len + 26] = E_KEY[2] = u32_in(in_key + 8); + D_KEY[key_len + 27] = E_KEY[3] = u32_in(in_key + 12); + + switch (key_len) { + case 16: + t = E_KEY[3]; + for (i = 0; i < 10; ++i) + loop4(i); + break; + + case 24: + E_KEY[4] = u32_in(in_key + 16); + t = E_KEY[5] = u32_in(in_key + 20); + for (i = 0; i < 8; ++i) + loop6 (i); + break; + + case 32: + E_KEY[4] = u32_in(in_key + 16); + E_KEY[5] = u32_in(in_key + 20); + E_KEY[6] = u32_in(in_key + 24); + t = E_KEY[7] = u32_in(in_key + 28); + for (i = 0; i < 7; ++i) + loop8(i); + break; + } + + D_KEY[0] = E_KEY[key_len + 24]; + D_KEY[1] = E_KEY[key_len + 25]; + D_KEY[2] = E_KEY[key_len + 26]; + D_KEY[3] = E_KEY[key_len + 27]; + + for (i = 4; i < key_len + 24; ++i) { + j = key_len + 24 - (i & ~3) + (i & 3); + imix_col(D_KEY[j], E_KEY[i]); + } + + return 0; +} + +extern void aes_encrypt(void *ctx_arg, u8 *out, const u8 *in); +extern void aes_decrypt(void *ctx_arg, u8 *out, const u8 *in); + +static struct crypto_alg aes_alg = { + .cra_name = "aes", + .cra_flags = CRYPTO_ALG_TYPE_CIPHER, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct aes_ctx), + .cra_module = THIS_MODULE, + .cra_list = LIST_HEAD_INIT(aes_alg.cra_list), + .cra_u = { + .cipher = { + .cia_min_keysize = AES_MIN_KEY_SIZE, + .cia_max_keysize = AES_MAX_KEY_SIZE, + .cia_setkey = aes_set_key, + .cia_encrypt = aes_encrypt, + .cia_decrypt = aes_decrypt + } + } +}; + +static int __init aes_init(void) +{ + gen_tabs(); + return crypto_register_alg(&aes_alg); +} + +static void __exit aes_fini(void) +{ + crypto_unregister_alg(&aes_alg); +} + +module_init(aes_init); +module_exit(aes_fini); + +MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); +MODULE_LICENSE("GPL"); |