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