| /* |
| * 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 <linux/kernel.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)) |
| |
| /* Control word. */ |
| struct cword { |
| unsigned int __attribute__ ((__packed__)) |
| rounds:4, |
| algo:3, |
| keygen:1, |
| interm:1, |
| encdec:1, |
| ksize:2; |
| } __attribute__ ((__aligned__(PADLOCK_ALIGNMENT))); |
| |
| /* Whenever making any changes to the following |
| * structure *make sure* you keep E, d_data |
| * and cword aligned on 16 Bytes boundaries!!! */ |
| struct aes_ctx { |
| struct { |
| struct cword encrypt; |
| struct cword decrypt; |
| } cword; |
| u32 *D; |
| int key_length; |
| u32 E[AES_EXTENDED_KEY_SIZE] |
| __attribute__ ((__aligned__(PADLOCK_ALIGNMENT))); |
| u32 d_data[AES_EXTENDED_KEY_SIZE] |
| __attribute__ ((__aligned__(PADLOCK_ALIGNMENT))); |
| }; |
| |
| /* ====== 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 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 inline struct aes_ctx *aes_ctx(struct crypto_tfm *tfm) |
| { |
| unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm); |
| unsigned long align = PADLOCK_ALIGNMENT; |
| |
| if (align <= crypto_tfm_ctx_alignment()) |
| align = 1; |
| return (struct aes_ctx *)ALIGN(addr, align); |
| } |
| |
| static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, |
| unsigned int key_len, u32 *flags) |
| { |
| struct aes_ctx *ctx = aes_ctx(tfm); |
| const __le32 *key = (const __le32 *)in_key; |
| 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; |
| |
| /* |
| * If the hardware is capable of generating the extended key |
| * itself we must supply the plain key for both encryption |
| * and decryption. |
| */ |
| ctx->D = ctx->E; |
| |
| 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]); |
| |
| /* Prepare control words. */ |
| memset(&ctx->cword, 0, sizeof(ctx->cword)); |
| |
| ctx->cword.decrypt.encdec = 1; |
| ctx->cword.encrypt.rounds = 10 + (key_len - 16) / 4; |
| ctx->cword.decrypt.rounds = ctx->cword.encrypt.rounds; |
| ctx->cword.encrypt.ksize = (key_len - 16) / 8; |
| ctx->cword.decrypt.ksize = ctx->cword.encrypt.ksize; |
| |
| /* Don't generate extended keys if the hardware can do it. */ |
| if (aes_hw_extkey_available(key_len)) |
| return 0; |
| |
| ctx->D = ctx->d_data; |
| ctx->cword.encrypt.keygen = 1; |
| ctx->cword.decrypt.keygen = 1; |
| |
| 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]); |
| } |
| |
| /* 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 ====== */ |
| |
| /* These are the real call to PadLock. */ |
| static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key, |
| void *control_word, u32 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 inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key, |
| u8 *iv, void *control_word, u32 count) |
| { |
| /* Enforce key reload. */ |
| asm volatile ("pushfl; popfl"); |
| /* rep xcryptcbc */ |
| asm volatile (".byte 0xf3,0x0f,0xa7,0xd0" |
| : "+S" (input), "+D" (output), "+a" (iv) |
| : "d" (control_word), "b" (key), "c" (count)); |
| return iv; |
| } |
| |
| static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| { |
| struct aes_ctx *ctx = aes_ctx(tfm); |
| padlock_xcrypt_ecb(in, out, ctx->E, &ctx->cword.encrypt, 1); |
| } |
| |
| static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| { |
| struct aes_ctx *ctx = aes_ctx(tfm); |
| padlock_xcrypt_ecb(in, out, ctx->D, &ctx->cword.decrypt, 1); |
| } |
| |
| static unsigned int aes_encrypt_ecb(const struct cipher_desc *desc, u8 *out, |
| const u8 *in, unsigned int nbytes) |
| { |
| struct aes_ctx *ctx = aes_ctx(desc->tfm); |
| padlock_xcrypt_ecb(in, out, ctx->E, &ctx->cword.encrypt, |
| nbytes / AES_BLOCK_SIZE); |
| return nbytes & ~(AES_BLOCK_SIZE - 1); |
| } |
| |
| static unsigned int aes_decrypt_ecb(const struct cipher_desc *desc, u8 *out, |
| const u8 *in, unsigned int nbytes) |
| { |
| struct aes_ctx *ctx = aes_ctx(desc->tfm); |
| padlock_xcrypt_ecb(in, out, ctx->D, &ctx->cword.decrypt, |
| nbytes / AES_BLOCK_SIZE); |
| return nbytes & ~(AES_BLOCK_SIZE - 1); |
| } |
| |
| static unsigned int aes_encrypt_cbc(const struct cipher_desc *desc, u8 *out, |
| const u8 *in, unsigned int nbytes) |
| { |
| struct aes_ctx *ctx = aes_ctx(desc->tfm); |
| u8 *iv; |
| |
| iv = padlock_xcrypt_cbc(in, out, ctx->E, desc->info, |
| &ctx->cword.encrypt, nbytes / AES_BLOCK_SIZE); |
| memcpy(desc->info, iv, AES_BLOCK_SIZE); |
| |
| return nbytes & ~(AES_BLOCK_SIZE - 1); |
| } |
| |
| static unsigned int aes_decrypt_cbc(const struct cipher_desc *desc, u8 *out, |
| const u8 *in, unsigned int nbytes) |
| { |
| struct aes_ctx *ctx = aes_ctx(desc->tfm); |
| padlock_xcrypt_cbc(in, out, ctx->D, desc->info, &ctx->cword.decrypt, |
| nbytes / AES_BLOCK_SIZE); |
| return nbytes & ~(AES_BLOCK_SIZE - 1); |
| } |
| |
| static struct crypto_alg aes_alg = { |
| .cra_name = "aes", |
| .cra_driver_name = "aes-padlock", |
| .cra_priority = PADLOCK_CRA_PRIORITY, |
| .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
| .cra_blocksize = AES_BLOCK_SIZE, |
| .cra_ctxsize = sizeof(struct aes_ctx), |
| .cra_alignmask = PADLOCK_ALIGNMENT - 1, |
| .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, |
| .cia_encrypt_ecb = aes_encrypt_ecb, |
| .cia_decrypt_ecb = aes_decrypt_ecb, |
| .cia_encrypt_cbc = aes_encrypt_cbc, |
| .cia_decrypt_cbc = aes_decrypt_cbc, |
| } |
| } |
| }; |
| |
| static int __init padlock_init(void) |
| { |
| int ret; |
| |
| if (!cpu_has_xcrypt) { |
| printk(KERN_ERR PFX "VIA PadLock not detected.\n"); |
| return -ENODEV; |
| } |
| |
| if (!cpu_has_xcrypt_enabled) { |
| printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n"); |
| return -ENODEV; |
| } |
| |
| gen_tabs(); |
| if ((ret = crypto_register_alg(&aes_alg))) { |
| printk(KERN_ERR PFX "VIA PadLock AES initialization failed.\n"); |
| return ret; |
| } |
| |
| printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n"); |
| |
| return ret; |
| } |
| |
| static void __exit padlock_fini(void) |
| { |
| crypto_unregister_alg(&aes_alg); |
| } |
| |
| module_init(padlock_init); |
| module_exit(padlock_fini); |
| |
| MODULE_DESCRIPTION("VIA PadLock AES algorithm support"); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Michal Ludvig"); |
| |
| MODULE_ALIAS("aes-padlock"); |
