linux/drivers/crypto/padlock-sha.c
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   1/*
   2 * Cryptographic API.
   3 *
   4 * Support for VIA PadLock hardware crypto engine.
   5 *
   6 * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 *
  13 */
  14
  15#include <crypto/algapi.h>
  16#include <crypto/sha.h>
  17#include <linux/err.h>
  18#include <linux/module.h>
  19#include <linux/init.h>
  20#include <linux/errno.h>
  21#include <linux/cryptohash.h>
  22#include <linux/interrupt.h>
  23#include <linux/kernel.h>
  24#include <linux/scatterlist.h>
  25#include <asm/i387.h>
  26#include "padlock.h"
  27
  28#define SHA1_DEFAULT_FALLBACK   "sha1-generic"
  29#define SHA256_DEFAULT_FALLBACK "sha256-generic"
  30
  31struct padlock_sha_ctx {
  32        char            *data;
  33        size_t          used;
  34        int             bypass;
  35        void (*f_sha_padlock)(const char *in, char *out, int count);
  36        struct hash_desc fallback;
  37};
  38
  39static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
  40{
  41        return crypto_tfm_ctx(tfm);
  42}
  43
  44/* We'll need aligned address on the stack */
  45#define NEAREST_ALIGNED(ptr) \
  46        ((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
  47
  48static struct crypto_alg sha1_alg, sha256_alg;
  49
  50static void padlock_sha_bypass(struct crypto_tfm *tfm)
  51{
  52        if (ctx(tfm)->bypass)
  53                return;
  54
  55        crypto_hash_init(&ctx(tfm)->fallback);
  56        if (ctx(tfm)->data && ctx(tfm)->used) {
  57                struct scatterlist sg;
  58
  59                sg_init_one(&sg, ctx(tfm)->data, ctx(tfm)->used);
  60                crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
  61        }
  62
  63        ctx(tfm)->used = 0;
  64        ctx(tfm)->bypass = 1;
  65}
  66
  67static void padlock_sha_init(struct crypto_tfm *tfm)
  68{
  69        ctx(tfm)->used = 0;
  70        ctx(tfm)->bypass = 0;
  71}
  72
  73static void padlock_sha_update(struct crypto_tfm *tfm,
  74                        const uint8_t *data, unsigned int length)
  75{
  76        /* Our buffer is always one page. */
  77        if (unlikely(!ctx(tfm)->bypass &&
  78                     (ctx(tfm)->used + length > PAGE_SIZE)))
  79                padlock_sha_bypass(tfm);
  80
  81        if (unlikely(ctx(tfm)->bypass)) {
  82                struct scatterlist sg;
  83                sg_init_one(&sg, (uint8_t *)data, length);
  84                crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
  85                return;
  86        }
  87
  88        memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
  89        ctx(tfm)->used += length;
  90}
  91
  92static inline void padlock_output_block(uint32_t *src,
  93                        uint32_t *dst, size_t count)
  94{
  95        while (count--)
  96                *dst++ = swab32(*src++);
  97}
  98
  99static void padlock_do_sha1(const char *in, char *out, int count)
 100{
 101        /* We can't store directly to *out as it may be unaligned. */
 102        /* BTW Don't reduce the buffer size below 128 Bytes!
 103         *     PadLock microcode needs it that big. */
 104        char buf[128+16];
 105        char *result = NEAREST_ALIGNED(buf);
 106        int ts_state;
 107
 108        ((uint32_t *)result)[0] = SHA1_H0;
 109        ((uint32_t *)result)[1] = SHA1_H1;
 110        ((uint32_t *)result)[2] = SHA1_H2;
 111        ((uint32_t *)result)[3] = SHA1_H3;
 112        ((uint32_t *)result)[4] = SHA1_H4;
 113 
 114        /* prevent taking the spurious DNA fault with padlock. */
 115        ts_state = irq_ts_save();
 116        asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
 117                      : "+S"(in), "+D"(result)
 118                      : "c"(count), "a"(0));
 119        irq_ts_restore(ts_state);
 120
 121        padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
 122}
 123
 124static void padlock_do_sha256(const char *in, char *out, int count)
 125{
 126        /* We can't store directly to *out as it may be unaligned. */
 127        /* BTW Don't reduce the buffer size below 128 Bytes!
 128         *     PadLock microcode needs it that big. */
 129        char buf[128+16];
 130        char *result = NEAREST_ALIGNED(buf);
 131        int ts_state;
 132
 133        ((uint32_t *)result)[0] = SHA256_H0;
 134        ((uint32_t *)result)[1] = SHA256_H1;
 135        ((uint32_t *)result)[2] = SHA256_H2;
 136        ((uint32_t *)result)[3] = SHA256_H3;
 137        ((uint32_t *)result)[4] = SHA256_H4;
 138        ((uint32_t *)result)[5] = SHA256_H5;
 139        ((uint32_t *)result)[6] = SHA256_H6;
 140        ((uint32_t *)result)[7] = SHA256_H7;
 141
 142        /* prevent taking the spurious DNA fault with padlock. */
 143        ts_state = irq_ts_save();
 144        asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
 145                      : "+S"(in), "+D"(result)
 146                      : "c"(count), "a"(0));
 147        irq_ts_restore(ts_state);
 148
 149        padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
 150}
 151
 152static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
 153{
 154        if (unlikely(ctx(tfm)->bypass)) {
 155                crypto_hash_final(&ctx(tfm)->fallback, out);
 156                ctx(tfm)->bypass = 0;
 157                return;
 158        }
 159
 160        /* Pass the input buffer to PadLock microcode... */
 161        ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
 162
 163        ctx(tfm)->used = 0;
 164}
 165
 166static int padlock_cra_init(struct crypto_tfm *tfm)
 167{
 168        const char *fallback_driver_name = tfm->__crt_alg->cra_name;
 169        struct crypto_hash *fallback_tfm;
 170
 171        /* For now we'll allocate one page. This
 172         * could eventually be configurable one day. */
 173        ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
 174        if (!ctx(tfm)->data)
 175                return -ENOMEM;
 176
 177        /* Allocate a fallback and abort if it failed. */
 178        fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
 179                                         CRYPTO_ALG_ASYNC |
 180                                         CRYPTO_ALG_NEED_FALLBACK);
 181        if (IS_ERR(fallback_tfm)) {
 182                printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
 183                       fallback_driver_name);
 184                free_page((unsigned long)(ctx(tfm)->data));
 185                return PTR_ERR(fallback_tfm);
 186        }
 187
 188        ctx(tfm)->fallback.tfm = fallback_tfm;
 189        return 0;
 190}
 191
 192static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
 193{
 194        ctx(tfm)->f_sha_padlock = padlock_do_sha1;
 195
 196        return padlock_cra_init(tfm);
 197}
 198
 199static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
 200{
 201        ctx(tfm)->f_sha_padlock = padlock_do_sha256;
 202
 203        return padlock_cra_init(tfm);
 204}
 205
 206static void padlock_cra_exit(struct crypto_tfm *tfm)
 207{
 208        if (ctx(tfm)->data) {
 209                free_page((unsigned long)(ctx(tfm)->data));
 210                ctx(tfm)->data = NULL;
 211        }
 212
 213        crypto_free_hash(ctx(tfm)->fallback.tfm);
 214        ctx(tfm)->fallback.tfm = NULL;
 215}
 216
 217static struct crypto_alg sha1_alg = {
 218        .cra_name               =       "sha1",
 219        .cra_driver_name        =       "sha1-padlock",
 220        .cra_priority           =       PADLOCK_CRA_PRIORITY,
 221        .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
 222                                        CRYPTO_ALG_NEED_FALLBACK,
 223        .cra_blocksize          =       SHA1_BLOCK_SIZE,
 224        .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
 225        .cra_module             =       THIS_MODULE,
 226        .cra_list               =       LIST_HEAD_INIT(sha1_alg.cra_list),
 227        .cra_init               =       padlock_sha1_cra_init,
 228        .cra_exit               =       padlock_cra_exit,
 229        .cra_u                  =       {
 230                .digest = {
 231                        .dia_digestsize =       SHA1_DIGEST_SIZE,
 232                        .dia_init       =       padlock_sha_init,
 233                        .dia_update     =       padlock_sha_update,
 234                        .dia_final      =       padlock_sha_final,
 235                }
 236        }
 237};
 238
 239static struct crypto_alg sha256_alg = {
 240        .cra_name               =       "sha256",
 241        .cra_driver_name        =       "sha256-padlock",
 242        .cra_priority           =       PADLOCK_CRA_PRIORITY,
 243        .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
 244                                        CRYPTO_ALG_NEED_FALLBACK,
 245        .cra_blocksize          =       SHA256_BLOCK_SIZE,
 246        .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
 247        .cra_module             =       THIS_MODULE,
 248        .cra_list               =       LIST_HEAD_INIT(sha256_alg.cra_list),
 249        .cra_init               =       padlock_sha256_cra_init,
 250        .cra_exit               =       padlock_cra_exit,
 251        .cra_u                  =       {
 252                .digest = {
 253                        .dia_digestsize =       SHA256_DIGEST_SIZE,
 254                        .dia_init       =       padlock_sha_init,
 255                        .dia_update     =       padlock_sha_update,
 256                        .dia_final      =       padlock_sha_final,
 257                }
 258        }
 259};
 260
 261static int __init padlock_init(void)
 262{
 263        int rc = -ENODEV;
 264
 265        if (!cpu_has_phe) {
 266                printk(KERN_NOTICE PFX "VIA PadLock Hash Engine not detected.\n");
 267                return -ENODEV;
 268        }
 269
 270        if (!cpu_has_phe_enabled) {
 271                printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
 272                return -ENODEV;
 273        }
 274
 275        rc = crypto_register_alg(&sha1_alg);
 276        if (rc)
 277                goto out;
 278
 279        rc = crypto_register_alg(&sha256_alg);
 280        if (rc)
 281                goto out_unreg1;
 282
 283        printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
 284
 285        return 0;
 286
 287out_unreg1:
 288        crypto_unregister_alg(&sha1_alg);
 289out:
 290        printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
 291        return rc;
 292}
 293
 294static void __exit padlock_fini(void)
 295{
 296        crypto_unregister_alg(&sha1_alg);
 297        crypto_unregister_alg(&sha256_alg);
 298}
 299
 300module_init(padlock_init);
 301module_exit(padlock_fini);
 302
 303MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
 304MODULE_LICENSE("GPL");
 305MODULE_AUTHOR("Michal Ludvig");
 306
 307MODULE_ALIAS("sha1");
 308MODULE_ALIAS("sha256");
 309MODULE_ALIAS("sha1-padlock");
 310MODULE_ALIAS("sha256-padlock");
 311
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