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