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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/crypto/padlock-aes.c | |
download | linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/crypto/padlock-aes.c')
-rw-r--r-- | drivers/crypto/padlock-aes.c | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/drivers/crypto/padlock-aes.c b/drivers/crypto/padlock-aes.c new file mode 100644 index 00000000000..ed708b4427b --- /dev/null +++ b/drivers/crypto/padlock-aes.c @@ -0,0 +1,468 @@ +/* + * Cryptographic API. + * + * Support for VIA PadLock hardware crypto engine. + * + * Copyright (c) 2004 Michal Ludvig <michal@logix.cz> + * + * Key expansion routine taken from crypto/aes.c + * + * 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. + * --------------------------------------------------------------------------- + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/crypto.h> +#include <linux/interrupt.h> +#include <asm/byteorder.h> +#include "padlock.h" + +#define AES_MIN_KEY_SIZE 16 /* in uint8_t units */ +#define AES_MAX_KEY_SIZE 32 /* ditto */ +#define AES_BLOCK_SIZE 16 /* ditto */ +#define AES_EXTENDED_KEY_SIZE 64 /* in uint32_t units */ +#define AES_EXTENDED_KEY_SIZE_B (AES_EXTENDED_KEY_SIZE * sizeof(uint32_t)) + +struct aes_ctx { + uint32_t e_data[AES_EXTENDED_KEY_SIZE+4]; + uint32_t d_data[AES_EXTENDED_KEY_SIZE+4]; + uint32_t *E; + uint32_t *D; + int key_length; +}; + +/* ====== Key management routines ====== */ + +static inline uint32_t +generic_rotr32 (const uint32_t x, const unsigned bits) +{ + const unsigned n = bits % 32; + return (x >> n) | (x << (32 - n)); +} + +static inline uint32_t +generic_rotl32 (const uint32_t x, const unsigned bits) +{ + const unsigned n = bits % 32; + return (x << n) | (x >> (32 - n)); +} + +#define rotl generic_rotl32 +#define rotr generic_rotr32 + +/* + * #define byte(x, nr) ((unsigned char)((x) >> (nr*8))) + */ +static inline uint8_t +byte(const uint32_t x, const unsigned n) +{ + return x >> (n << 3); +} + +#define uint32_t_in(x) le32_to_cpu(*(const uint32_t *)(x)) +#define uint32_t_out(to, from) (*(uint32_t *)(to) = cpu_to_le32(from)) + +#define E_KEY ctx->E +#define D_KEY ctx->D + +static uint8_t pow_tab[256]; +static uint8_t log_tab[256]; +static uint8_t sbx_tab[256]; +static uint8_t isb_tab[256]; +static uint32_t rco_tab[10]; +static uint32_t ft_tab[4][256]; +static uint32_t it_tab[4][256]; + +static uint32_t fl_tab[4][256]; +static uint32_t il_tab[4][256]; + +static inline uint8_t +f_mult (uint8_t a, uint8_t b) +{ + uint8_t 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 +gen_tabs (void) +{ + uint32_t i, t; + uint8_t p, q; + + /* log and power tables for GF(2**8) finite field with + 0x011b as modular polynomial - the simplest prmitive + root is 0x03, used here to generate the tables */ + + for (i = 0, p = 1; i < 256; ++i) { + pow_tab[i] = (uint8_t) p; + log_tab[p] = (uint8_t) 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] = (uint8_t) i; + } + + for (i = 0; i < 256; ++i) { + p = sbx_tab[i]; + + t = p; + fl_tab[0][i] = t; + fl_tab[1][i] = rotl (t, 8); + fl_tab[2][i] = rotl (t, 16); + fl_tab[3][i] = rotl (t, 24); + + t = ((uint32_t) ff_mult (2, p)) | + ((uint32_t) p << 8) | + ((uint32_t) p << 16) | ((uint32_t) ff_mult (3, p) << 24); + + ft_tab[0][i] = t; + ft_tab[1][i] = rotl (t, 8); + ft_tab[2][i] = rotl (t, 16); + ft_tab[3][i] = rotl (t, 24); + + p = isb_tab[i]; + + t = p; + il_tab[0][i] = t; + il_tab[1][i] = rotl (t, 8); + il_tab[2][i] = rotl (t, 16); + il_tab[3][i] = rotl (t, 24); + + t = ((uint32_t) ff_mult (14, p)) | + ((uint32_t) ff_mult (9, p) << 8) | + ((uint32_t) ff_mult (13, p) << 16) | + ((uint32_t) ff_mult (11, p) << 24); + + it_tab[0][i] = t; + it_tab[1][i] = rotl (t, 8); + it_tab[2][i] = rotl (t, 16); + it_tab[3][i] = rotl (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) ^= rotr(u ^ t, 8) ^ \ + rotr(v ^ t, 16) ^ \ + rotr(t,24) + +/* initialise the key schedule from the user supplied key */ + +#define loop4(i) \ +{ t = rotr(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 = rotr(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 = rotr(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; \ +} + +/* Tells whether the ACE is capable to generate + the extended key for a given key_len. */ +static inline int +aes_hw_extkey_available(uint8_t key_len) +{ + /* TODO: We should check the actual CPU model/stepping + as it's possible that the capability will be + added in the next CPU revisions. */ + if (key_len == 16) + return 1; + return 0; +} + +static int +aes_set_key(void *ctx_arg, const uint8_t *in_key, unsigned int key_len, uint32_t *flags) +{ + struct aes_ctx *ctx = ctx_arg; + uint32_t i, t, u, v, w; + uint32_t P[AES_EXTENDED_KEY_SIZE]; + uint32_t rounds; + + if (key_len != 16 && key_len != 24 && key_len != 32) { + *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + ctx->key_length = key_len; + + ctx->E = ctx->e_data; + ctx->D = ctx->d_data; + + /* Ensure 16-Bytes alignmentation of keys for VIA PadLock. */ + if ((int)(ctx->e_data) & 0x0F) + ctx->E += 4 - (((int)(ctx->e_data) & 0x0F) / sizeof (ctx->e_data[0])); + + if ((int)(ctx->d_data) & 0x0F) + ctx->D += 4 - (((int)(ctx->d_data) & 0x0F) / sizeof (ctx->d_data[0])); + + E_KEY[0] = uint32_t_in (in_key); + E_KEY[1] = uint32_t_in (in_key + 4); + E_KEY[2] = uint32_t_in (in_key + 8); + E_KEY[3] = uint32_t_in (in_key + 12); + + /* Don't generate extended keys if the hardware can do it. */ + if (aes_hw_extkey_available(key_len)) + return 0; + + switch (key_len) { + case 16: + t = E_KEY[3]; + for (i = 0; i < 10; ++i) + loop4 (i); + break; + + case 24: + E_KEY[4] = uint32_t_in (in_key + 16); + t = E_KEY[5] = uint32_t_in (in_key + 20); + for (i = 0; i < 8; ++i) + loop6 (i); + break; + + case 32: + E_KEY[4] = uint32_t_in (in_key + 16); + E_KEY[5] = uint32_t_in (in_key + 20); + E_KEY[6] = uint32_t_in (in_key + 24); + t = E_KEY[7] = uint32_t_in (in_key + 28); + 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]); + } + + /* PadLock needs a different format of the decryption key. */ + rounds = 10 + (key_len - 16) / 4; + + for (i = 0; i < rounds; i++) { + P[((i + 1) * 4) + 0] = D_KEY[((rounds - i - 1) * 4) + 0]; + P[((i + 1) * 4) + 1] = D_KEY[((rounds - i - 1) * 4) + 1]; + P[((i + 1) * 4) + 2] = D_KEY[((rounds - i - 1) * 4) + 2]; + P[((i + 1) * 4) + 3] = D_KEY[((rounds - i - 1) * 4) + 3]; + } + + P[0] = E_KEY[(rounds * 4) + 0]; + P[1] = E_KEY[(rounds * 4) + 1]; + P[2] = E_KEY[(rounds * 4) + 2]; + P[3] = E_KEY[(rounds * 4) + 3]; + + memcpy(D_KEY, P, AES_EXTENDED_KEY_SIZE_B); + + return 0; +} + +/* ====== Encryption/decryption routines ====== */ + +/* This is the real call to PadLock. */ +static inline void +padlock_xcrypt_ecb(uint8_t *input, uint8_t *output, uint8_t *key, + void *control_word, uint32_t count) +{ + asm volatile ("pushfl; popfl"); /* enforce key reload. */ + asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */ + : "+S"(input), "+D"(output) + : "d"(control_word), "b"(key), "c"(count)); +} + +static void +aes_padlock(void *ctx_arg, uint8_t *out_arg, const uint8_t *in_arg, int encdec) +{ + /* Don't blindly modify this structure - the items must + fit on 16-Bytes boundaries! */ + struct padlock_xcrypt_data { + uint8_t buf[AES_BLOCK_SIZE]; + union cword cword; + }; + + struct aes_ctx *ctx = ctx_arg; + char bigbuf[sizeof(struct padlock_xcrypt_data) + 16]; + struct padlock_xcrypt_data *data; + void *key; + + /* Place 'data' at the first 16-Bytes aligned address in 'bigbuf'. */ + if (((long)bigbuf) & 0x0F) + data = (void*)(bigbuf + 16 - ((long)bigbuf & 0x0F)); + else + data = (void*)bigbuf; + + /* Prepare Control word. */ + memset (data, 0, sizeof(struct padlock_xcrypt_data)); + data->cword.b.encdec = !encdec; /* in the rest of cryptoapi ENC=1/DEC=0 */ + data->cword.b.rounds = 10 + (ctx->key_length - 16) / 4; + data->cword.b.ksize = (ctx->key_length - 16) / 8; + + /* Is the hardware capable to generate the extended key? */ + if (!aes_hw_extkey_available(ctx->key_length)) + data->cword.b.keygen = 1; + + /* ctx->E starts with a plain key - if the hardware is capable + to generate the extended key itself we must supply + the plain key for both Encryption and Decryption. */ + if (encdec == CRYPTO_DIR_ENCRYPT || data->cword.b.keygen == 0) + key = ctx->E; + else + key = ctx->D; + + memcpy(data->buf, in_arg, AES_BLOCK_SIZE); + padlock_xcrypt_ecb(data->buf, data->buf, key, &data->cword, 1); + memcpy(out_arg, data->buf, AES_BLOCK_SIZE); +} + +static void +aes_encrypt(void *ctx_arg, uint8_t *out, const uint8_t *in) +{ + aes_padlock(ctx_arg, out, in, CRYPTO_DIR_ENCRYPT); +} + +static void +aes_decrypt(void *ctx_arg, uint8_t *out, const uint8_t *in) +{ + aes_padlock(ctx_arg, out, in, CRYPTO_DIR_DECRYPT); +} + +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 + } + } +}; + +int __init padlock_init_aes(void) +{ + printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n"); + + gen_tabs(); + return crypto_register_alg(&aes_alg); +} + +void __exit padlock_fini_aes(void) +{ + crypto_unregister_alg(&aes_alg); +} |