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/algapi.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/cryptohash.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/kernel.h>
  24 #include <linux/scatterlist.h>
  25 #include "padlock.h"
  26
  27 #define SHA1_DEFAULT_FALLBACK   "sha1-generic"
  28 #define SHA256_DEFAULT_FALLBACK "sha256-generic"
  29
  30 struct padlock_sha_ctx {
  31         char            *data;
  32         size_t          used;
  33         int             bypass;
  34         void (*f_sha_padlock)(const char *in, char *out, int count);
  35         struct hash_desc fallback;
  36 };
  37
  38 static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
  39 {
  40         return crypto_tfm_ctx(tfm);
  41 }
  42
  43 /* We'll need aligned address on the stack */
  44 #define NEAREST_ALIGNED(ptr) \
  45         ((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
  46
  47 static struct crypto_alg sha1_alg, sha256_alg;
  48
  49 static void padlock_sha_bypass(struct crypto_tfm *tfm)
  50 {
  51         if (ctx(tfm)->bypass)
  52                 return;
  53
  54         crypto_hash_init(&ctx(tfm)->fallback);
  55         if (ctx(tfm)->data && ctx(tfm)->used) {
  56                 struct scatterlist sg;
  57
  58                 sg_init_one(&sg, ctx(tfm)->data, ctx(tfm)->used);
  59                 crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
  60         }
  61
  62         ctx(tfm)->used = 0;
  63         ctx(tfm)->bypass = 1;
  64 }
  65
  66 static void padlock_sha_init(struct crypto_tfm *tfm)
  67 {
  68         ctx(tfm)->used = 0;
  69         ctx(tfm)->bypass = 0;
  70 }
  71
  72 static void padlock_sha_update(struct crypto_tfm *tfm,
  73                         const uint8_t *data, unsigned int length)
  74 {
  75         /* Our buffer is always one page. */
  76         if (unlikely(!ctx(tfm)->bypass &&
  77                      (ctx(tfm)->used + length > PAGE_SIZE)))
  78                 padlock_sha_bypass(tfm);
  79
  80         if (unlikely(ctx(tfm)->bypass)) {
  81                 struct scatterlist sg;
  82                 sg_init_one(&sg, (uint8_t *)data, length);
  83                 crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
  84                 return;
  85         }
  86
  87         memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
  88         ctx(tfm)->used += length;
  89 }
  90
  91 static inline void padlock_output_block(uint32_t *src,
  92                         uint32_t *dst, size_t count)
  93 {
  94         while (count--)
  95                 *dst++ = swab32(*src++);
  96 }
  97
  98 static void padlock_do_sha1(const char *in, char *out, int count)
  99 {
 100         /* We can't store directly to *out as it may be unaligned. */
 101         /* BTW Don't reduce the buffer size below 128 Bytes!
 102          *     PadLock microcode needs it that big. */
 103         char buf[128+16];
 104         char *result = NEAREST_ALIGNED(buf);
 105
 106         ((uint32_t *)result)[0] = SHA1_H0;
 107         ((uint32_t *)result)[1] = SHA1_H1;
 108         ((uint32_t *)result)[2] = SHA1_H2;
 109         ((uint32_t *)result)[3] = SHA1_H3;
 110         ((uint32_t *)result)[4] = SHA1_H4;
 111
 112         asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
 113                       : "+S"(in), "+D"(result)
 114                       : "c"(count), "a"(0));
 115
 116         padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
 117 }
 118
 119 static void padlock_do_sha256(const char *in, char *out, int count)
 120 {
 121         /* We can't store directly to *out as it may be unaligned. */
 122         /* BTW Don't reduce the buffer size below 128 Bytes!
 123          *     PadLock microcode needs it that big. */
 124         char buf[128+16];
 125         char *result = NEAREST_ALIGNED(buf);
 126
 127         ((uint32_t *)result)[0] = SHA256_H0;
 128         ((uint32_t *)result)[1] = SHA256_H1;
 129         ((uint32_t *)result)[2] = SHA256_H2;
 130         ((uint32_t *)result)[3] = SHA256_H3;
 131         ((uint32_t *)result)[4] = SHA256_H4;
 132         ((uint32_t *)result)[5] = SHA256_H5;
 133         ((uint32_t *)result)[6] = SHA256_H6;
 134         ((uint32_t *)result)[7] = SHA256_H7;
 135
 136         asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
 137                       : "+S"(in), "+D"(result)
 138                       : "c"(count), "a"(0));
 139
 140         padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
 141 }
 142
 143 static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
 144 {
 145         if (unlikely(ctx(tfm)->bypass)) {
 146                 crypto_hash_final(&ctx(tfm)->fallback, out);
 147                 ctx(tfm)->bypass = 0;
 148                 return;
 149         }
 150
 151         /* Pass the input buffer to PadLock microcode... */
 152         ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
 153
 154         ctx(tfm)->used = 0;
 155 }
 156
 157 static int padlock_cra_init(struct crypto_tfm *tfm)
 158 {
 159         const char *fallback_driver_name = tfm->__crt_alg->cra_name;
 160         struct crypto_hash *fallback_tfm;
 161
 162         /* For now we'll allocate one page. This
 163          * could eventually be configurable one day. */
 164         ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
 165         if (!ctx(tfm)->data)
 166                 return -ENOMEM;
 167
 168         /* Allocate a fallback and abort if it failed. */
 169         fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
 170                                          CRYPTO_ALG_ASYNC |
 171                                          CRYPTO_ALG_NEED_FALLBACK);
 172         if (IS_ERR(fallback_tfm)) {
 173                 printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
 174                        fallback_driver_name);
 175                 free_page((unsigned long)(ctx(tfm)->data));
 176                 return PTR_ERR(fallback_tfm);
 177         }
 178
 179         ctx(tfm)->fallback.tfm = fallback_tfm;
 180         return 0;
 181 }
 182
 183 static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
 184 {
 185         ctx(tfm)->f_sha_padlock = padlock_do_sha1;
 186
 187         return padlock_cra_init(tfm);
 188 }
 189
 190 static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
 191 {
 192         ctx(tfm)->f_sha_padlock = padlock_do_sha256;
 193
 194         return padlock_cra_init(tfm);
 195 }
 196
 197 static void padlock_cra_exit(struct crypto_tfm *tfm)
 198 {
 199         if (ctx(tfm)->data) {
 200                 free_page((unsigned long)(ctx(tfm)->data));
 201                 ctx(tfm)->data = NULL;
 202         }
 203
 204         crypto_free_hash(ctx(tfm)->fallback.tfm);
 205         ctx(tfm)->fallback.tfm = NULL;
 206 }
 207
 208 static struct crypto_alg sha1_alg = {
 209         .cra_name               =       "sha1",
 210         .cra_driver_name        =       "sha1-padlock",
 211         .cra_priority           =       PADLOCK_CRA_PRIORITY,
 212         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
 213                                         CRYPTO_ALG_NEED_FALLBACK,
 214         .cra_blocksize          =       SHA1_BLOCK_SIZE,
 215         .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
 216         .cra_module             =       THIS_MODULE,
 217         .cra_list               =       LIST_HEAD_INIT(sha1_alg.cra_list),
 218         .cra_init               =       padlock_sha1_cra_init,
 219         .cra_exit               =       padlock_cra_exit,
 220         .cra_u                  =       {
 221                 .digest = {
 222                         .dia_digestsize =       SHA1_DIGEST_SIZE,
 223                         .dia_init       =       padlock_sha_init,
 224                         .dia_update     =       padlock_sha_update,
 225                         .dia_final      =       padlock_sha_final,
 226                 }
 227         }
 228 };
 229
 230 static struct crypto_alg sha256_alg = {
 231         .cra_name               =       "sha256",
 232         .cra_driver_name        =       "sha256-padlock",
 233         .cra_priority           =       PADLOCK_CRA_PRIORITY,
 234         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
 235                                         CRYPTO_ALG_NEED_FALLBACK,
 236         .cra_blocksize          =       SHA256_BLOCK_SIZE,
 237         .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
 238         .cra_module             =       THIS_MODULE,
 239         .cra_list               =       LIST_HEAD_INIT(sha256_alg.cra_list),
 240         .cra_init               =       padlock_sha256_cra_init,
 241         .cra_exit               =       padlock_cra_exit,
 242         .cra_u                  =       {
 243                 .digest = {
 244                         .dia_digestsize =       SHA256_DIGEST_SIZE,
 245                         .dia_init       =       padlock_sha_init,
 246                         .dia_update     =       padlock_sha_update,
 247                         .dia_final      =       padlock_sha_final,
 248                 }
 249         }
 250 };
 251
 252 static int __init padlock_init(void)
 253 {
 254         int rc = -ENODEV;
 255
 256         if (!cpu_has_phe) {
 257                 printk(KERN_ERR PFX "VIA PadLock Hash Engine not detected.\n");
 258                 return -ENODEV;
 259         }
 260
 261         if (!cpu_has_phe_enabled) {
 262                 printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
 263                 return -ENODEV;
 264         }
 265
 266         rc = crypto_register_alg(&sha1_alg);
 267         if (rc)
 268                 goto out;
 269
 270         rc = crypto_register_alg(&sha256_alg);
 271         if (rc)
 272                 goto out_unreg1;
 273
 274         printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
 275
 276         return 0;
 277
 278 out_unreg1:
 279         crypto_unregister_alg(&sha1_alg);
 280 out:
 281         printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
 282         return rc;
 283 }
 284
 285 static void __exit padlock_fini(void)
 286 {
 287         crypto_unregister_alg(&sha1_alg);
 288         crypto_unregister_alg(&sha256_alg);
 289 }
 290
 291 module_init(padlock_init);
 292 module_exit(padlock_fini);
 293
 294 MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
 295 MODULE_LICENSE("GPL");
 296 MODULE_AUTHOR("Michal Ludvig");
 297
 298 MODULE_ALIAS("sha1");
 299 MODULE_ALIAS("sha256");
 300 MODULE_ALIAS("sha1-padlock");
 301 MODULE_ALIAS("sha256-padlock");