| /* |
| * 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). |
| * |
| * 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 <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/types.h> |
| #include <linux/errno.h> |
| #include <linux/crypto.h> |
| #include <asm/byteorder.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); |
| } |
| |
| struct aes_ctx { |
| int 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]; |
| static u32 ft_tab[4][256]; |
| static u32 it_tab[4][256]; |
| |
| static u32 fl_tab[4][256]; |
| static u32 il_tab[4][256]; |
| |
| static inline u8 __init |
| 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 f_rn(bo, bi, n, k) \ |
| bo[n] = ft_tab[0][byte(bi[n],0)] ^ \ |
| ft_tab[1][byte(bi[(n + 1) & 3],1)] ^ \ |
| ft_tab[2][byte(bi[(n + 2) & 3],2)] ^ \ |
| ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n) |
| |
| #define i_rn(bo, bi, n, k) \ |
| bo[n] = it_tab[0][byte(bi[n],0)] ^ \ |
| it_tab[1][byte(bi[(n + 3) & 3],1)] ^ \ |
| it_tab[2][byte(bi[(n + 2) & 3],2)] ^ \ |
| it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n) |
| |
| #define ls_box(x) \ |
| ( fl_tab[0][byte(x, 0)] ^ \ |
| fl_tab[1][byte(x, 1)] ^ \ |
| fl_tab[2][byte(x, 2)] ^ \ |
| fl_tab[3][byte(x, 3)] ) |
| |
| #define f_rl(bo, bi, n, k) \ |
| bo[n] = fl_tab[0][byte(bi[n],0)] ^ \ |
| fl_tab[1][byte(bi[(n + 1) & 3],1)] ^ \ |
| fl_tab[2][byte(bi[(n + 2) & 3],2)] ^ \ |
| fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n) |
| |
| #define i_rl(bo, bi, n, k) \ |
| bo[n] = il_tab[0][byte(bi[n],0)] ^ \ |
| il_tab[1][byte(bi[(n + 3) & 3],1)] ^ \ |
| il_tab[2][byte(bi[(n + 2) & 3],2)] ^ \ |
| il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n) |
| |
| 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; |
| fl_tab[0][i] = t; |
| fl_tab[1][i] = rol32(t, 8); |
| fl_tab[2][i] = rol32(t, 16); |
| 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); |
| |
| ft_tab[0][i] = t; |
| ft_tab[1][i] = rol32(t, 8); |
| ft_tab[2][i] = rol32(t, 16); |
| ft_tab[3][i] = rol32(t, 24); |
| |
| p = isb_tab[i]; |
| |
| t = p; |
| il_tab[0][i] = t; |
| il_tab[1][i] = rol32(t, 8); |
| il_tab[2][i] = rol32(t, 16); |
| 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); |
| |
| it_tab[0][i] = t; |
| it_tab[1][i] = rol32(t, 8); |
| it_tab[2][i] = rol32(t, 16); |
| 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; |
| const __le32 *key = (const __le32 *)in_key; |
| u32 i, 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; |
| |
| E_KEY[0] = le32_to_cpu(key[0]); |
| E_KEY[1] = le32_to_cpu(key[1]); |
| E_KEY[2] = le32_to_cpu(key[2]); |
| E_KEY[3] = le32_to_cpu(key[3]); |
| |
| switch (key_len) { |
| case 16: |
| t = E_KEY[3]; |
| for (i = 0; i < 10; ++i) |
| loop4 (i); |
| break; |
| |
| case 24: |
| E_KEY[4] = le32_to_cpu(key[4]); |
| t = E_KEY[5] = le32_to_cpu(key[5]); |
| for (i = 0; i < 8; ++i) |
| loop6 (i); |
| break; |
| |
| case 32: |
| E_KEY[4] = le32_to_cpu(key[4]); |
| E_KEY[5] = le32_to_cpu(key[5]); |
| E_KEY[6] = le32_to_cpu(key[6]); |
| t = E_KEY[7] = le32_to_cpu(key[7]); |
| for (i = 0; i < 7; ++i) |
| loop8 (i); |
| break; |
| } |
| |
| D_KEY[0] = E_KEY[0]; |
| D_KEY[1] = E_KEY[1]; |
| D_KEY[2] = E_KEY[2]; |
| D_KEY[3] = E_KEY[3]; |
| |
| for (i = 4; i < key_len + 24; ++i) { |
| imix_col (D_KEY[i], E_KEY[i]); |
| } |
| |
| return 0; |
| } |
| |
| /* encrypt a block of text */ |
| |
| #define f_nround(bo, bi, k) \ |
| f_rn(bo, bi, 0, k); \ |
| f_rn(bo, bi, 1, k); \ |
| f_rn(bo, bi, 2, k); \ |
| f_rn(bo, bi, 3, k); \ |
| k += 4 |
| |
| #define f_lround(bo, bi, k) \ |
| f_rl(bo, bi, 0, k); \ |
| f_rl(bo, bi, 1, k); \ |
| f_rl(bo, bi, 2, k); \ |
| f_rl(bo, bi, 3, k) |
| |
| static void aes_encrypt(void *ctx_arg, u8 *out, const u8 *in) |
| { |
| const struct aes_ctx *ctx = ctx_arg; |
| const __le32 *src = (const __le32 *)in; |
| __le32 *dst = (__le32 *)out; |
| u32 b0[4], b1[4]; |
| const u32 *kp = E_KEY + 4; |
| |
| b0[0] = le32_to_cpu(src[0]) ^ E_KEY[0]; |
| b0[1] = le32_to_cpu(src[1]) ^ E_KEY[1]; |
| b0[2] = le32_to_cpu(src[2]) ^ E_KEY[2]; |
| b0[3] = le32_to_cpu(src[3]) ^ E_KEY[3]; |
| |
| if (ctx->key_length > 24) { |
| f_nround (b1, b0, kp); |
| f_nround (b0, b1, kp); |
| } |
| |
| if (ctx->key_length > 16) { |
| f_nround (b1, b0, kp); |
| f_nround (b0, b1, kp); |
| } |
| |
| f_nround (b1, b0, kp); |
| f_nround (b0, b1, kp); |
| f_nround (b1, b0, kp); |
| f_nround (b0, b1, kp); |
| f_nround (b1, b0, kp); |
| f_nround (b0, b1, kp); |
| f_nround (b1, b0, kp); |
| f_nround (b0, b1, kp); |
| f_nround (b1, b0, kp); |
| f_lround (b0, b1, kp); |
| |
| dst[0] = cpu_to_le32(b0[0]); |
| dst[1] = cpu_to_le32(b0[1]); |
| dst[2] = cpu_to_le32(b0[2]); |
| dst[3] = cpu_to_le32(b0[3]); |
| } |
| |
| /* decrypt a block of text */ |
| |
| #define i_nround(bo, bi, k) \ |
| i_rn(bo, bi, 0, k); \ |
| i_rn(bo, bi, 1, k); \ |
| i_rn(bo, bi, 2, k); \ |
| i_rn(bo, bi, 3, k); \ |
| k -= 4 |
| |
| #define i_lround(bo, bi, k) \ |
| i_rl(bo, bi, 0, k); \ |
| i_rl(bo, bi, 1, k); \ |
| i_rl(bo, bi, 2, k); \ |
| i_rl(bo, bi, 3, k) |
| |
| static void aes_decrypt(void *ctx_arg, u8 *out, const u8 *in) |
| { |
| const struct aes_ctx *ctx = ctx_arg; |
| const __le32 *src = (const __le32 *)in; |
| __le32 *dst = (__le32 *)out; |
| u32 b0[4], b1[4]; |
| const int key_len = ctx->key_length; |
| const u32 *kp = D_KEY + key_len + 20; |
| |
| b0[0] = le32_to_cpu(src[0]) ^ E_KEY[key_len + 24]; |
| b0[1] = le32_to_cpu(src[1]) ^ E_KEY[key_len + 25]; |
| b0[2] = le32_to_cpu(src[2]) ^ E_KEY[key_len + 26]; |
| b0[3] = le32_to_cpu(src[3]) ^ E_KEY[key_len + 27]; |
| |
| if (key_len > 24) { |
| i_nround (b1, b0, kp); |
| i_nround (b0, b1, kp); |
| } |
| |
| if (key_len > 16) { |
| i_nround (b1, b0, kp); |
| i_nround (b0, b1, kp); |
| } |
| |
| i_nround (b1, b0, kp); |
| i_nround (b0, b1, kp); |
| i_nround (b1, b0, kp); |
| i_nround (b0, b1, kp); |
| i_nround (b1, b0, kp); |
| i_nround (b0, b1, kp); |
| i_nround (b1, b0, kp); |
| i_nround (b0, b1, kp); |
| i_nround (b1, b0, kp); |
| i_lround (b0, b1, kp); |
| |
| dst[0] = cpu_to_le32(b0[0]); |
| dst[1] = cpu_to_le32(b0[1]); |
| dst[2] = cpu_to_le32(b0[2]); |
| dst[3] = cpu_to_le32(b0[3]); |
| } |
| |
| |
| 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("Dual BSD/GPL"); |
| |