drivers/crypto/padlock-sha.c

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