/*  * 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 u8byte(const u32 x, const unsigned n){	return x >> (n << 3);} struct aes_ctx {	int key_length;	u32 buf[120];}; #define E_KEY (&ctx->buf[0])#define D_KEY (&ctx->buf[60]) 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 __initf_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 __initgen_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 intaes_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_driver_name	=	"aes-generic",	.cra_priority		=	100,	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,	.cra_blocksize		=	AES_BLOCK_SIZE,	.cra_ctxsize		=	sizeof(struct aes_ctx),	.cra_alignmask		=	3,	.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");