--- /dev/null
+/*
+ * 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);
+}
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