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Diffstat (limited to 'arch/i386/crypto/aes.c')
| -rw-r--r-- | arch/i386/crypto/aes.c | 520 |
1 files changed, 520 insertions, 0 deletions
diff --git a/arch/i386/crypto/aes.c b/arch/i386/crypto/aes.c new file mode 100644 index 00000000000..1019430fc1f --- /dev/null +++ b/arch/i386/crypto/aes.c @@ -0,0 +1,520 @@ +/* + * + * Glue Code for optimized 586 assembler version of AES + * + * Copyright (c) 2002, Dr Brian Gladman <>, 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. + * + * Copyright (c) 2003, Adam J. Richter <adam@yggdrasil.com> (conversion to + * 2.5 API). + * Copyright (c) 2003, 2004 Fruhwirth Clemens <clemens@endorphin.org> + * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> + * + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/crypto.h> +#include <linux/linkage.h> + +asmlinkage void aes_enc_blk(const u8 *src, u8 *dst, void *ctx); +asmlinkage void aes_dec_blk(const u8 *src, u8 *dst, void *ctx); + +#define AES_MIN_KEY_SIZE 16 +#define AES_MAX_KEY_SIZE 32 +#define AES_BLOCK_SIZE 16 +#define AES_KS_LENGTH 4 * AES_BLOCK_SIZE +#define RC_LENGTH 29 + +struct aes_ctx { + u32 ekey[AES_KS_LENGTH]; + u32 rounds; + u32 dkey[AES_KS_LENGTH]; +}; + +#define WPOLY 0x011b +#define u32_in(x) le32_to_cpu(*(const u32 *)(x)) +#define bytes2word(b0, b1, b2, b3) \ + (((u32)(b3) << 24) | ((u32)(b2) << 16) | ((u32)(b1) << 8) | (b0)) + +/* define the finite field multiplies required for Rijndael */ +#define f2(x) ((x) ? pow[log[x] + 0x19] : 0) +#define f3(x) ((x) ? pow[log[x] + 0x01] : 0) +#define f9(x) ((x) ? pow[log[x] + 0xc7] : 0) +#define fb(x) ((x) ? pow[log[x] + 0x68] : 0) +#define fd(x) ((x) ? pow[log[x] + 0xee] : 0) +#define fe(x) ((x) ? pow[log[x] + 0xdf] : 0) +#define fi(x) ((x) ? pow[255 - log[x]]: 0) + +static inline u32 upr(u32 x, int n) +{ + return (x << 8 * n) | (x >> (32 - 8 * n)); +} + +static inline u8 bval(u32 x, int n) +{ + return x >> 8 * n; +} + +/* The forward and inverse affine transformations used in the S-box */ +#define fwd_affine(x) \ + (w = (u32)x, w ^= (w<<1)^(w<<2)^(w<<3)^(w<<4), 0x63^(u8)(w^(w>>8))) + +#define inv_affine(x) \ + (w = (u32)x, w = (w<<1)^(w<<3)^(w<<6), 0x05^(u8)(w^(w>>8))) + +static u32 rcon_tab[RC_LENGTH]; + +u32 ft_tab[4][256]; +u32 fl_tab[4][256]; +static u32 ls_tab[4][256]; +static u32 im_tab[4][256]; +u32 il_tab[4][256]; +u32 it_tab[4][256]; + +static void gen_tabs(void) +{ + u32 i, w; + u8 pow[512], log[256]; + + /* + * log and power tables for GF(2^8) finite field with + * WPOLY as modular polynomial - the simplest primitive + * root is 0x03, used here to generate the tables. + */ + i = 0; w = 1; + + do { + pow[i] = (u8)w; + pow[i + 255] = (u8)w; + log[w] = (u8)i++; + w ^= (w << 1) ^ (w & 0x80 ? WPOLY : 0); + } while (w != 1); + + for(i = 0, w = 1; i < RC_LENGTH; ++i) { + rcon_tab[i] = bytes2word(w, 0, 0, 0); + w = f2(w); + } + + for(i = 0; i < 256; ++i) { + u8 b; + + b = fwd_affine(fi((u8)i)); + w = bytes2word(f2(b), b, b, f3(b)); + + /* tables for a normal encryption round */ + ft_tab[0][i] = w; + ft_tab[1][i] = upr(w, 1); + ft_tab[2][i] = upr(w, 2); + ft_tab[3][i] = upr(w, 3); + w = bytes2word(b, 0, 0, 0); + + /* + * tables for last encryption round + * (may also be used in the key schedule) + */ + fl_tab[0][i] = w; + fl_tab[1][i] = upr(w, 1); + fl_tab[2][i] = upr(w, 2); + fl_tab[3][i] = upr(w, 3); + + /* + * table for key schedule if fl_tab above is + * not of the required form + */ + ls_tab[0][i] = w; + ls_tab[1][i] = upr(w, 1); + ls_tab[2][i] = upr(w, 2); + ls_tab[3][i] = upr(w, 3); + + b = fi(inv_affine((u8)i)); + w = bytes2word(fe(b), f9(b), fd(b), fb(b)); + + /* tables for the inverse mix column operation */ + im_tab[0][b] = w; + im_tab[1][b] = upr(w, 1); + im_tab[2][b] = upr(w, 2); + im_tab[3][b] = upr(w, 3); + + /* tables for a normal decryption round */ + it_tab[0][i] = w; + it_tab[1][i] = upr(w,1); + it_tab[2][i] = upr(w,2); + it_tab[3][i] = upr(w,3); + + w = bytes2word(b, 0, 0, 0); + + /* tables for last decryption round */ + il_tab[0][i] = w; + il_tab[1][i] = upr(w,1); + il_tab[2][i] = upr(w,2); + il_tab[3][i] = upr(w,3); + } +} + +#define four_tables(x,tab,vf,rf,c) \ +( tab[0][bval(vf(x,0,c),rf(0,c))] ^ \ + tab[1][bval(vf(x,1,c),rf(1,c))] ^ \ + tab[2][bval(vf(x,2,c),rf(2,c))] ^ \ + tab[3][bval(vf(x,3,c),rf(3,c))] \ +) + +#define vf1(x,r,c) (x) +#define rf1(r,c) (r) +#define rf2(r,c) ((r-c)&3) + +#define inv_mcol(x) four_tables(x,im_tab,vf1,rf1,0) +#define ls_box(x,c) four_tables(x,fl_tab,vf1,rf2,c) + +#define ff(x) inv_mcol(x) + +#define ke4(k,i) \ +{ \ + k[4*(i)+4] = ss[0] ^= ls_box(ss[3],3) ^ rcon_tab[i]; \ + k[4*(i)+5] = ss[1] ^= ss[0]; \ + k[4*(i)+6] = ss[2] ^= ss[1]; \ + k[4*(i)+7] = ss[3] ^= ss[2]; \ +} + +#define kel4(k,i) \ +{ \ + k[4*(i)+4] = ss[0] ^= ls_box(ss[3],3) ^ rcon_tab[i]; \ + k[4*(i)+5] = ss[1] ^= ss[0]; \ + k[4*(i)+6] = ss[2] ^= ss[1]; k[4*(i)+7] = ss[3] ^= ss[2]; \ +} + +#define ke6(k,i) \ +{ \ + k[6*(i)+ 6] = ss[0] ^= ls_box(ss[5],3) ^ rcon_tab[i]; \ + k[6*(i)+ 7] = ss[1] ^= ss[0]; \ + k[6*(i)+ 8] = ss[2] ^= ss[1]; \ + k[6*(i)+ 9] = ss[3] ^= ss[2]; \ + k[6*(i)+10] = ss[4] ^= ss[3]; \ + k[6*(i)+11] = ss[5] ^= ss[4]; \ +} + +#define kel6(k,i) \ +{ \ + k[6*(i)+ 6] = ss[0] ^= ls_box(ss[5],3) ^ rcon_tab[i]; \ + k[6*(i)+ 7] = ss[1] ^= ss[0]; \ + k[6*(i)+ 8] = ss[2] ^= ss[1]; \ + k[6*(i)+ 9] = ss[3] ^= ss[2]; \ +} + +#define ke8(k,i) \ +{ \ + k[8*(i)+ 8] = ss[0] ^= ls_box(ss[7],3) ^ rcon_tab[i]; \ + k[8*(i)+ 9] = ss[1] ^= ss[0]; \ + k[8*(i)+10] = ss[2] ^= ss[1]; \ + k[8*(i)+11] = ss[3] ^= ss[2]; \ + k[8*(i)+12] = ss[4] ^= ls_box(ss[3],0); \ + k[8*(i)+13] = ss[5] ^= ss[4]; \ + k[8*(i)+14] = ss[6] ^= ss[5]; \ + k[8*(i)+15] = ss[7] ^= ss[6]; \ +} + +#define kel8(k,i) \ +{ \ + k[8*(i)+ 8] = ss[0] ^= ls_box(ss[7],3) ^ rcon_tab[i]; \ + k[8*(i)+ 9] = ss[1] ^= ss[0]; \ + k[8*(i)+10] = ss[2] ^= ss[1]; \ + k[8*(i)+11] = ss[3] ^= ss[2]; \ +} + +#define kdf4(k,i) \ +{ \ + ss[0] = ss[0] ^ ss[2] ^ ss[1] ^ ss[3]; \ + ss[1] = ss[1] ^ ss[3]; \ + ss[2] = ss[2] ^ ss[3]; \ + ss[3] = ss[3]; \ + ss[4] = ls_box(ss[(i+3) % 4], 3) ^ rcon_tab[i]; \ + ss[i % 4] ^= ss[4]; \ + ss[4] ^= k[4*(i)]; \ + k[4*(i)+4] = ff(ss[4]); \ + ss[4] ^= k[4*(i)+1]; \ + k[4*(i)+5] = ff(ss[4]); \ + ss[4] ^= k[4*(i)+2]; \ + k[4*(i)+6] = ff(ss[4]); \ + ss[4] ^= k[4*(i)+3]; \ + k[4*(i)+7] = ff(ss[4]); \ +} + +#define kd4(k,i) \ +{ \ + ss[4] = ls_box(ss[(i+3) % 4], 3) ^ rcon_tab[i]; \ + ss[i % 4] ^= ss[4]; \ + ss[4] = ff(ss[4]); \ + k[4*(i)+4] = ss[4] ^= k[4*(i)]; \ + k[4*(i)+5] = ss[4] ^= k[4*(i)+1]; \ + k[4*(i)+6] = ss[4] ^= k[4*(i)+2]; \ + k[4*(i)+7] = ss[4] ^= k[4*(i)+3]; \ +} + +#define kdl4(k,i) \ +{ \ + ss[4] = ls_box(ss[(i+3) % 4], 3) ^ rcon_tab[i]; \ + ss[i % 4] ^= ss[4]; \ + k[4*(i)+4] = (ss[0] ^= ss[1]) ^ ss[2] ^ ss[3]; \ + k[4*(i)+5] = ss[1] ^ ss[3]; \ + k[4*(i)+6] = ss[0]; \ + k[4*(i)+7] = ss[1]; \ +} + +#define kdf6(k,i) \ +{ \ + ss[0] ^= ls_box(ss[5],3) ^ rcon_tab[i]; \ + k[6*(i)+ 6] = ff(ss[0]); \ + ss[1] ^= ss[0]; \ + k[6*(i)+ 7] = ff(ss[1]); \ + ss[2] ^= ss[1]; \ + k[6*(i)+ 8] = ff(ss[2]); \ + ss[3] ^= ss[2]; \ + k[6*(i)+ 9] = ff(ss[3]); \ + ss[4] ^= ss[3]; \ + k[6*(i)+10] = ff(ss[4]); \ + ss[5] ^= ss[4]; \ + k[6*(i)+11] = ff(ss[5]); \ +} + +#define kd6(k,i) \ +{ \ + ss[6] = ls_box(ss[5],3) ^ rcon_tab[i]; \ + ss[0] ^= ss[6]; ss[6] = ff(ss[6]); \ + k[6*(i)+ 6] = ss[6] ^= k[6*(i)]; \ + ss[1] ^= ss[0]; \ + k[6*(i)+ 7] = ss[6] ^= k[6*(i)+ 1]; \ + ss[2] ^= ss[1]; \ + k[6*(i)+ 8] = ss[6] ^= k[6*(i)+ 2]; \ + ss[3] ^= ss[2]; \ + k[6*(i)+ 9] = ss[6] ^= k[6*(i)+ 3]; \ + ss[4] ^= ss[3]; \ + k[6*(i)+10] = ss[6] ^= k[6*(i)+ 4]; \ + ss[5] ^= ss[4]; \ + k[6*(i)+11] = ss[6] ^= k[6*(i)+ 5]; \ +} + +#define kdl6(k,i) \ +{ \ + ss[0] ^= ls_box(ss[5],3) ^ rcon_tab[i]; \ + k[6*(i)+ 6] = ss[0]; \ + ss[1] ^= ss[0]; \ + k[6*(i)+ 7] = ss[1]; \ + ss[2] ^= ss[1]; \ + k[6*(i)+ 8] = ss[2]; \ + ss[3] ^= ss[2]; \ + k[6*(i)+ 9] = ss[3]; \ +} + +#define kdf8(k,i) \ +{ \ + ss[0] ^= ls_box(ss[7],3) ^ rcon_tab[i]; \ + k[8*(i)+ 8] = ff(ss[0]); \ + ss[1] ^= ss[0]; \ + k[8*(i)+ 9] = ff(ss[1]); \ + ss[2] ^= ss[1]; \ + k[8*(i)+10] = ff(ss[2]); \ + ss[3] ^= ss[2]; \ + k[8*(i)+11] = ff(ss[3]); \ + ss[4] ^= ls_box(ss[3],0); \ + k[8*(i)+12] = ff(ss[4]); \ + ss[5] ^= ss[4]; \ + k[8*(i)+13] = ff(ss[5]); \ + ss[6] ^= ss[5]; \ + k[8*(i)+14] = ff(ss[6]); \ + ss[7] ^= ss[6]; \ + k[8*(i)+15] = ff(ss[7]); \ +} + +#define kd8(k,i) \ +{ \ + u32 __g = ls_box(ss[7],3) ^ rcon_tab[i]; \ + ss[0] ^= __g; \ + __g = ff(__g); \ + k[8*(i)+ 8] = __g ^= k[8*(i)]; \ + ss[1] ^= ss[0]; \ + k[8*(i)+ 9] = __g ^= k[8*(i)+ 1]; \ + ss[2] ^= ss[1]; \ + k[8*(i)+10] = __g ^= k[8*(i)+ 2]; \ + ss[3] ^= ss[2]; \ + k[8*(i)+11] = __g ^= k[8*(i)+ 3]; \ + __g = ls_box(ss[3],0); \ + ss[4] ^= __g; \ + __g = ff(__g); \ + k[8*(i)+12] = __g ^= k[8*(i)+ 4]; \ + ss[5] ^= ss[4]; \ + k[8*(i)+13] = __g ^= k[8*(i)+ 5]; \ + ss[6] ^= ss[5]; \ + k[8*(i)+14] = __g ^= k[8*(i)+ 6]; \ + ss[7] ^= ss[6]; \ + k[8*(i)+15] = __g ^= k[8*(i)+ 7]; \ +} + +#define kdl8(k,i) \ +{ \ + ss[0] ^= ls_box(ss[7],3) ^ rcon_tab[i]; \ + k[8*(i)+ 8] = ss[0]; \ + ss[1] ^= ss[0]; \ + k[8*(i)+ 9] = ss[1]; \ + ss[2] ^= ss[1]; \ + k[8*(i)+10] = ss[2]; \ + ss[3] ^= ss[2]; \ + k[8*(i)+11] = ss[3]; \ +} + +static int +aes_set_key(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags) +{ + int i; + u32 ss[8]; + struct aes_ctx *ctx = ctx_arg; + + /* encryption schedule */ + + ctx->ekey[0] = ss[0] = u32_in(in_key); + ctx->ekey[1] = ss[1] = u32_in(in_key + 4); + ctx->ekey[2] = ss[2] = u32_in(in_key + 8); + ctx->ekey[3] = ss[3] = u32_in(in_key + 12); + + switch(key_len) { + case 16: + for (i = 0; i < 9; i++) + ke4(ctx->ekey, i); + kel4(ctx->ekey, 9); + ctx->rounds = 10; + break; + + case 24: + ctx->ekey[4] = ss[4] = u32_in(in_key + 16); + ctx->ekey[5] = ss[5] = u32_in(in_key + 20); + for (i = 0; i < 7; i++) + ke6(ctx->ekey, i); + kel6(ctx->ekey, 7); + ctx->rounds = 12; + break; + + case 32: + ctx->ekey[4] = ss[4] = u32_in(in_key + 16); + ctx->ekey[5] = ss[5] = u32_in(in_key + 20); + ctx->ekey[6] = ss[6] = u32_in(in_key + 24); + ctx->ekey[7] = ss[7] = u32_in(in_key + 28); + for (i = 0; i < 6; i++) + ke8(ctx->ekey, i); + kel8(ctx->ekey, 6); + ctx->rounds = 14; + break; + + default: + *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + /* decryption schedule */ + + ctx->dkey[0] = ss[0] = u32_in(in_key); + ctx->dkey[1] = ss[1] = u32_in(in_key + 4); + ctx->dkey[2] = ss[2] = u32_in(in_key + 8); + ctx->dkey[3] = ss[3] = u32_in(in_key + 12); + + switch (key_len) { + case 16: + kdf4(ctx->dkey, 0); + for (i = 1; i < 9; i++) + kd4(ctx->dkey, i); + kdl4(ctx->dkey, 9); + break; + + case 24: + ctx->dkey[4] = ff(ss[4] = u32_in(in_key + 16)); + ctx->dkey[5] = ff(ss[5] = u32_in(in_key + 20)); + kdf6(ctx->dkey, 0); + for (i = 1; i < 7; i++) + kd6(ctx->dkey, i); + kdl6(ctx->dkey, 7); + break; + + case 32: + ctx->dkey[4] = ff(ss[4] = u32_in(in_key + 16)); + ctx->dkey[5] = ff(ss[5] = u32_in(in_key + 20)); + ctx->dkey[6] = ff(ss[6] = u32_in(in_key + 24)); + ctx->dkey[7] = ff(ss[7] = u32_in(in_key + 28)); + kdf8(ctx->dkey, 0); + for (i = 1; i < 6; i++) + kd8(ctx->dkey, i); + kdl8(ctx->dkey, 6); + break; + } + return 0; +} + +static inline void aes_encrypt(void *ctx, u8 *dst, const u8 *src) +{ + aes_enc_blk(src, dst, ctx); +} +static inline void aes_decrypt(void *ctx, u8 *dst, const u8 *src) +{ + aes_dec_blk(src, dst, ctx); +} + + +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, i586 asm optimized"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Fruhwirth Clemens, James Morris, Brian Gladman, Adam Richter"); +MODULE_ALIAS("aes"); |