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