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/internal/hash.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/interrupt.h>
  22#include <linux/kernel.h>
  23#include <linux/scatterlist.h>
  24#include <asm/i387.h>
  25#include "padlock.h"
  26
  27#ifdef CONFIG_64BIT
  28#define STACK_ALIGN 16
  29#else
  30#define STACK_ALIGN 4
  31#endif
  32
  33struct padlock_sha_desc {
  34        struct shash_desc fallback;
  35};
  36
  37struct padlock_sha_ctx {
  38        struct crypto_shash *fallback;
  39};
  40
  41static int padlock_sha_init(struct shash_desc *desc)
  42{
  43        struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
  44        struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
  45
  46        dctx->fallback.tfm = ctx->fallback;
  47        dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
  48        return crypto_shash_init(&dctx->fallback);
  49}
  50
  51static int padlock_sha_update(struct shash_desc *desc,
  52                              const u8 *data, unsigned int length)
  53{
  54        struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
  55
  56        dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
  57        return crypto_shash_update(&dctx->fallback, data, length);
  58}
  59
  60static int padlock_sha_export(struct shash_desc *desc, void *out)
  61{
  62        struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
  63
  64        return crypto_shash_export(&dctx->fallback, out);
  65}
  66
  67static int padlock_sha_import(struct shash_desc *desc, const void *in)
  68{
  69        struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
  70        struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
  71
  72        dctx->fallback.tfm = ctx->fallback;
  73        dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
  74        return crypto_shash_import(&dctx->fallback, in);
  75}
  76
  77static inline void padlock_output_block(uint32_t *src,
  78                        uint32_t *dst, size_t count)
  79{
  80        while (count--)
  81                *dst++ = swab32(*src++);
  82}
  83
  84static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
  85                              unsigned int count, u8 *out)
  86{
  87        /* We can't store directly to *out as it may be unaligned. */
  88        /* BTW Don't reduce the buffer size below 128 Bytes!
  89         *     PadLock microcode needs it that big. */
  90        char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
  91                ((aligned(STACK_ALIGN)));
  92        char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
  93        struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
  94        struct sha1_state state;
  95        unsigned int space;
  96        unsigned int leftover;
  97        int ts_state;
  98        int err;
  99
 100        dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 101        err = crypto_shash_export(&dctx->fallback, &state);
 102        if (err)
 103                goto out;
 104
 105        if (state.count + count > ULONG_MAX)
 106                return crypto_shash_finup(&dctx->fallback, in, count, out);
 107
 108        leftover = ((state.count - 1) & (SHA1_BLOCK_SIZE - 1)) + 1;
 109        space =  SHA1_BLOCK_SIZE - leftover;
 110        if (space) {
 111                if (count > space) {
 112                        err = crypto_shash_update(&dctx->fallback, in, space) ?:
 113                              crypto_shash_export(&dctx->fallback, &state);
 114                        if (err)
 115                                goto out;
 116                        count -= space;
 117                        in += space;
 118                } else {
 119                        memcpy(state.buffer + leftover, in, count);
 120                        in = state.buffer;
 121                        count += leftover;
 122                        state.count &= ~(SHA1_BLOCK_SIZE - 1);
 123                }
 124        }
 125
 126        memcpy(result, &state.state, SHA1_DIGEST_SIZE);
 127
 128        /* prevent taking the spurious DNA fault with padlock. */
 129        ts_state = irq_ts_save();
 130        asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
 131                      : \
 132                      : "c"((unsigned long)state.count + count), \
 133                        "a"((unsigned long)state.count), \
 134                        "S"(in), "D"(result));
 135        irq_ts_restore(ts_state);
 136
 137        padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
 138
 139out:
 140        return err;
 141}
 142
 143static int padlock_sha1_final(struct shash_desc *desc, u8 *out)
 144{
 145        u8 buf[4];
 146
 147        return padlock_sha1_finup(desc, buf, 0, out);
 148}
 149
 150static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
 151                                unsigned int count, u8 *out)
 152{
 153        /* We can't store directly to *out as it may be unaligned. */
 154        /* BTW Don't reduce the buffer size below 128 Bytes!
 155         *     PadLock microcode needs it that big. */
 156        char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
 157                ((aligned(STACK_ALIGN)));
 158        char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
 159        struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
 160        struct sha256_state state;
 161        unsigned int space;
 162        unsigned int leftover;
 163        int ts_state;
 164        int err;
 165
 166        dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 167        err = crypto_shash_export(&dctx->fallback, &state);
 168        if (err)
 169                goto out;
 170
 171        if (state.count + count > ULONG_MAX)
 172                return crypto_shash_finup(&dctx->fallback, in, count, out);
 173
 174        leftover = ((state.count - 1) & (SHA256_BLOCK_SIZE - 1)) + 1;
 175        space =  SHA256_BLOCK_SIZE - leftover;
 176        if (space) {
 177                if (count > space) {
 178                        err = crypto_shash_update(&dctx->fallback, in, space) ?:
 179                              crypto_shash_export(&dctx->fallback, &state);
 180                        if (err)
 181                                goto out;
 182                        count -= space;
 183                        in += space;
 184                } else {
 185                        memcpy(state.buf + leftover, in, count);
 186                        in = state.buf;
 187                        count += leftover;
 188                        state.count &= ~(SHA1_BLOCK_SIZE - 1);
 189                }
 190        }
 191
 192        memcpy(result, &state.state, SHA256_DIGEST_SIZE);
 193
 194        /* prevent taking the spurious DNA fault with padlock. */
 195        ts_state = irq_ts_save();
 196        asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
 197                      : \
 198                      : "c"((unsigned long)state.count + count), \
 199                        "a"((unsigned long)state.count), \
 200                        "S"(in), "D"(result));
 201        irq_ts_restore(ts_state);
 202
 203        padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
 204
 205out:
 206        return err;
 207}
 208
 209static int padlock_sha256_final(struct shash_desc *desc, u8 *out)
 210{
 211        u8 buf[4];
 212
 213        return padlock_sha256_finup(desc, buf, 0, out);
 214}
 215
 216static int padlock_cra_init(struct crypto_tfm *tfm)
 217{
 218        struct crypto_shash *hash = __crypto_shash_cast(tfm);
 219        const char *fallback_driver_name = tfm->__crt_alg->cra_name;
 220        struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
 221        struct crypto_shash *fallback_tfm;
 222        int err = -ENOMEM;
 223
 224        /* Allocate a fallback and abort if it failed. */
 225        fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
 226                                          CRYPTO_ALG_NEED_FALLBACK);
 227        if (IS_ERR(fallback_tfm)) {
 228                printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
 229                       fallback_driver_name);
 230                err = PTR_ERR(fallback_tfm);
 231                goto out;
 232        }
 233
 234        ctx->fallback = fallback_tfm;
 235        hash->descsize += crypto_shash_descsize(fallback_tfm);
 236        return 0;
 237
 238out:
 239        return err;
 240}
 241
 242static void padlock_cra_exit(struct crypto_tfm *tfm)
 243{
 244        struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
 245
 246        crypto_free_shash(ctx->fallback);
 247}
 248
 249static struct shash_alg sha1_alg = {
 250        .digestsize     =       SHA1_DIGEST_SIZE,
 251        .init           =       padlock_sha_init,
 252        .update         =       padlock_sha_update,
 253        .finup          =       padlock_sha1_finup,
 254        .final          =       padlock_sha1_final,
 255        .export         =       padlock_sha_export,
 256        .import         =       padlock_sha_import,
 257        .descsize       =       sizeof(struct padlock_sha_desc),
 258        .statesize      =       sizeof(struct sha1_state),
 259        .base           =       {
 260                .cra_name               =       "sha1",
 261                .cra_driver_name        =       "sha1-padlock",
 262                .cra_priority           =       PADLOCK_CRA_PRIORITY,
 263                .cra_flags              =       CRYPTO_ALG_TYPE_SHASH |
 264                                                CRYPTO_ALG_NEED_FALLBACK,
 265                .cra_blocksize          =       SHA1_BLOCK_SIZE,
 266                .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
 267                .cra_module             =       THIS_MODULE,
 268                .cra_init               =       padlock_cra_init,
 269                .cra_exit               =       padlock_cra_exit,
 270        }
 271};
 272
 273static struct shash_alg sha256_alg = {
 274        .digestsize     =       SHA256_DIGEST_SIZE,
 275        .init           =       padlock_sha_init,
 276        .update         =       padlock_sha_update,
 277        .finup          =       padlock_sha256_finup,
 278        .final          =       padlock_sha256_final,
 279        .export         =       padlock_sha_export,
 280        .import         =       padlock_sha_import,
 281        .descsize       =       sizeof(struct padlock_sha_desc),
 282        .statesize      =       sizeof(struct sha256_state),
 283        .base           =       {
 284                .cra_name               =       "sha256",
 285                .cra_driver_name        =       "sha256-padlock",
 286                .cra_priority           =       PADLOCK_CRA_PRIORITY,
 287                .cra_flags              =       CRYPTO_ALG_TYPE_SHASH |
 288                                                CRYPTO_ALG_NEED_FALLBACK,
 289                .cra_blocksize          =       SHA256_BLOCK_SIZE,
 290                .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
 291                .cra_module             =       THIS_MODULE,
 292                .cra_init               =       padlock_cra_init,
 293                .cra_exit               =       padlock_cra_exit,
 294        }
 295};
 296
 297static int __init padlock_init(void)
 298{
 299        int rc = -ENODEV;
 300
 301        if (!cpu_has_phe) {
 302                printk(KERN_NOTICE PFX "VIA PadLock Hash Engine not detected.\n");
 303                return -ENODEV;
 304        }
 305
 306        if (!cpu_has_phe_enabled) {
 307                printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
 308                return -ENODEV;
 309        }
 310
 311        rc = crypto_register_shash(&sha1_alg);
 312        if (rc)
 313                goto out;
 314
 315        rc = crypto_register_shash(&sha256_alg);
 316        if (rc)
 317                goto out_unreg1;
 318
 319        printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
 320
 321        return 0;
 322
 323out_unreg1:
 324        crypto_unregister_shash(&sha1_alg);
 325out:
 326        printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
 327        return rc;
 328}
 329
 330static void __exit padlock_fini(void)
 331{
 332        crypto_unregister_shash(&sha1_alg);
 333        crypto_unregister_shash(&sha256_alg);
 334}
 335
 336module_init(padlock_init);
 337module_exit(padlock_fini);
 338
 339MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
 340MODULE_LICENSE("GPL");
 341MODULE_AUTHOR("Michal Ludvig");
 342
 343MODULE_ALIAS("sha1-all");
 344MODULE_ALIAS("sha256-all");
 345MODULE_ALIAS("sha1-padlock");
 346MODULE_ALIAS("sha256-padlock");
 347