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 <linux/err.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/errno.h>
  20 #include <linux/cryptohash.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/kernel.h>
  23 #include <linux/scatterlist.h>
  24 #include "padlock.h"
  25
  26 #define SHA1_DEFAULT_FALLBACK   "sha1-generic"
  27 #define SHA1_DIGEST_SIZE        20
  28 #define SHA1_HMAC_BLOCK_SIZE    64
  29
  30 #define SHA256_DEFAULT_FALLBACK "sha256-generic"
  31 #define SHA256_DIGEST_SIZE      32
  32 #define SHA256_HMAC_BLOCK_SIZE  64
  33
  34 struct padlock_sha_ctx {
  35         char            *data;
  36         size_t          used;
  37         int             bypass;
  38         void (*f_sha_padlock)(const char *in, char *out, int count);
  39         struct hash_desc fallback;
  40 };
  41
  42 static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
  43 {
  44         return crypto_tfm_ctx(tfm);
  45 }
  46
  47 /* We'll need aligned address on the stack */
  48 #define NEAREST_ALIGNED(ptr) \
  49         ((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
  50
  51 static struct crypto_alg sha1_alg, sha256_alg;
  52
  53 static void padlock_sha_bypass(struct crypto_tfm *tfm)
  54 {
  55         if (ctx(tfm)->bypass)
  56                 return;
  57
  58         crypto_hash_init(&ctx(tfm)->fallback);
  59         if (ctx(tfm)->data && ctx(tfm)->used) {
  60                 struct scatterlist sg;
  61
  62                 sg_set_buf(&sg, ctx(tfm)->data, ctx(tfm)->used);
  63                 crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
  64         }
  65
  66         ctx(tfm)->used = 0;
  67         ctx(tfm)->bypass = 1;
  68 }
  69
  70 static void padlock_sha_init(struct crypto_tfm *tfm)
  71 {
  72         ctx(tfm)->used = 0;
  73         ctx(tfm)->bypass = 0;
  74 }
  75
  76 static void padlock_sha_update(struct crypto_tfm *tfm,
  77                         const uint8_t *data, unsigned int length)
  78 {
  79         /* Our buffer is always one page. */
  80         if (unlikely(!ctx(tfm)->bypass &&
  81                      (ctx(tfm)->used + length > PAGE_SIZE)))
  82                 padlock_sha_bypass(tfm);
  83
  84         if (unlikely(ctx(tfm)->bypass)) {
  85                 struct scatterlist sg;
  86                 sg_set_buf(&sg, (uint8_t *)data, length);
  87                 crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
  88                 return;
  89         }
  90
  91         memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
  92         ctx(tfm)->used += length;
  93 }
  94
  95 static inline void padlock_output_block(uint32_t *src,
  96                         uint32_t *dst, size_t count)
  97 {
  98         while (count--)
  99                 *dst++ = swab32(*src++);
 100 }
 101
 102 static void padlock_do_sha1(const char *in, char *out, int count)
 103 {
 104         /* We can't store directly to *out as it may be unaligned. */
 105         /* BTW Don't reduce the buffer size below 128 Bytes!
 106          *     PadLock microcode needs it that big. */
 107         char buf[128+16];
 108         char *result = NEAREST_ALIGNED(buf);
 109
 110         ((uint32_t *)result)[0] = 0x67452301;
 111         ((uint32_t *)result)[1] = 0xEFCDAB89;
 112         ((uint32_t *)result)[2] = 0x98BADCFE;
 113         ((uint32_t *)result)[3] = 0x10325476;
 114         ((uint32_t *)result)[4] = 0xC3D2E1F0;
 115
 116         asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
 117                       : "+S"(in), "+D"(result)
 118                       : "c"(count), "a"(0));
 119
 120         padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
 121 }
 122
 123 static void padlock_do_sha256(const char *in, char *out, int count)
 124 {
 125         /* We can't store directly to *out as it may be unaligned. */
 126         /* BTW Don't reduce the buffer size below 128 Bytes!
 127          *     PadLock microcode needs it that big. */
 128         char buf[128+16];
 129         char *result = NEAREST_ALIGNED(buf);
 130
 131         ((uint32_t *)result)[0] = 0x6A09E667;
 132         ((uint32_t *)result)[1] = 0xBB67AE85;
 133         ((uint32_t *)result)[2] = 0x3C6EF372;
 134         ((uint32_t *)result)[3] = 0xA54FF53A;
 135         ((uint32_t *)result)[4] = 0x510E527F;
 136         ((uint32_t *)result)[5] = 0x9B05688C;
 137         ((uint32_t *)result)[6] = 0x1F83D9AB;
 138         ((uint32_t *)result)[7] = 0x5BE0CD19;
 139
 140         asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
 141                       : "+S"(in), "+D"(result)
 142                       : "c"(count), "a"(0));
 143
 144         padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
 145 }
 146
 147 static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
 148 {
 149         if (unlikely(ctx(tfm)->bypass)) {
 150                 crypto_hash_final(&ctx(tfm)->fallback, out);
 151                 ctx(tfm)->bypass = 0;
 152                 return;
 153         }
 154
 155         /* Pass the input buffer to PadLock microcode... */
 156         ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
 157
 158         ctx(tfm)->used = 0;
 159 }
 160
 161 static int padlock_cra_init(struct crypto_tfm *tfm)
 162 {
 163         const char *fallback_driver_name = tfm->__crt_alg->cra_name;
 164         struct crypto_hash *fallback_tfm;
 165
 166         /* For now we'll allocate one page. This
 167          * could eventually be configurable one day. */
 168         ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
 169         if (!ctx(tfm)->data)
 170                 return -ENOMEM;
 171
 172         /* Allocate a fallback and abort if it failed. */
 173         fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
 174                                          CRYPTO_ALG_ASYNC |
 175                                          CRYPTO_ALG_NEED_FALLBACK);
 176         if (IS_ERR(fallback_tfm)) {
 177                 printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
 178                        fallback_driver_name);
 179                 free_page((unsigned long)(ctx(tfm)->data));
 180                 return PTR_ERR(fallback_tfm);
 181         }
 182
 183         ctx(tfm)->fallback.tfm = fallback_tfm;
 184         return 0;
 185 }
 186
 187 static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
 188 {
 189         ctx(tfm)->f_sha_padlock = padlock_do_sha1;
 190
 191         return padlock_cra_init(tfm);
 192 }
 193
 194 static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
 195 {
 196         ctx(tfm)->f_sha_padlock = padlock_do_sha256;
 197
 198         return padlock_cra_init(tfm);
 199 }
 200
 201 static void padlock_cra_exit(struct crypto_tfm *tfm)
 202 {
 203         if (ctx(tfm)->data) {
 204                 free_page((unsigned long)(ctx(tfm)->data));
 205                 ctx(tfm)->data = NULL;
 206         }
 207
 208         crypto_free_hash(ctx(tfm)->fallback.tfm);
 209         ctx(tfm)->fallback.tfm = NULL;
 210 }
 211
 212 static struct crypto_alg sha1_alg = {
 213         .cra_name               =       "sha1",
 214         .cra_driver_name        =       "sha1-padlock",
 215         .cra_priority           =       PADLOCK_CRA_PRIORITY,
 216         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
 217                                         CRYPTO_ALG_NEED_FALLBACK,
 218         .cra_blocksize          =       SHA1_HMAC_BLOCK_SIZE,
 219         .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
 220         .cra_module             =       THIS_MODULE,
 221         .cra_list               =       LIST_HEAD_INIT(sha1_alg.cra_list),
 222         .cra_init               =       padlock_sha1_cra_init,
 223         .cra_exit               =       padlock_cra_exit,
 224         .cra_u                  =       {
 225                 .digest = {
 226                         .dia_digestsize =       SHA1_DIGEST_SIZE,
 227                         .dia_init       =       padlock_sha_init,
 228                         .dia_update     =       padlock_sha_update,
 229                         .dia_final      =       padlock_sha_final,
 230                 }
 231         }
 232 };
 233
 234 static struct crypto_alg sha256_alg = {
 235         .cra_name               =       "sha256",
 236         .cra_driver_name        =       "sha256-padlock",
 237         .cra_priority           =       PADLOCK_CRA_PRIORITY,
 238         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
 239                                         CRYPTO_ALG_NEED_FALLBACK,
 240         .cra_blocksize          =       SHA256_HMAC_BLOCK_SIZE,
 241         .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
 242         .cra_module             =       THIS_MODULE,
 243         .cra_list               =       LIST_HEAD_INIT(sha256_alg.cra_list),
 244         .cra_init               =       padlock_sha256_cra_init,
 245         .cra_exit               =       padlock_cra_exit,
 246         .cra_u                  =       {
 247                 .digest = {
 248                         .dia_digestsize =       SHA256_DIGEST_SIZE,
 249                         .dia_init       =       padlock_sha_init,
 250                         .dia_update     =       padlock_sha_update,
 251                         .dia_final      =       padlock_sha_final,
 252                 }
 253         }
 254 };
 255
 256 static void __init padlock_sha_check_fallbacks(void)
 257 {
 258         if (!crypto_has_hash("sha1", 0, CRYPTO_ALG_ASYNC |
 259                                         CRYPTO_ALG_NEED_FALLBACK))
 260                 printk(KERN_WARNING PFX
 261                        "Couldn't load fallback module for sha1.\n");
 262
 263         if (!crypto_has_hash("sha256", 0, CRYPTO_ALG_ASYNC |
 264                                         CRYPTO_ALG_NEED_FALLBACK))
 265                 printk(KERN_WARNING PFX
 266                        "Couldn't load fallback module for sha256.\n");
 267 }
 268
 269 static int __init padlock_init(void)
 270 {
 271         int rc = -ENODEV;
 272
 273         if (!cpu_has_phe) {
 274                 printk(KERN_ERR PFX "VIA PadLock Hash Engine not detected.\n");
 275                 return -ENODEV;
 276         }
 277
 278         if (!cpu_has_phe_enabled) {
 279                 printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
 280                 return -ENODEV;
 281         }
 282
 283         padlock_sha_check_fallbacks();
 284
 285         rc = crypto_register_alg(&sha1_alg);
 286         if (rc)
 287                 goto out;
 288
 289         rc = crypto_register_alg(&sha256_alg);
 290         if (rc)
 291                 goto out_unreg1;
 292
 293         printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
 294
 295         return 0;
 296
 297 out_unreg1:
 298         crypto_unregister_alg(&sha1_alg);
 299 out:
 300         printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
 301         return rc;
 302 }
 303
 304 static void __exit padlock_fini(void)
 305 {
 306         crypto_unregister_alg(&sha1_alg);
 307         crypto_unregister_alg(&sha256_alg);
 308 }
 309
 310 module_init(padlock_init);
 311 module_exit(padlock_fini);
 312
 313 MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
 314 MODULE_LICENSE("GPL");
 315 MODULE_AUTHOR("Michal Ludvig");
 316
 317 MODULE_ALIAS("sha1-padlock");
 318 MODULE_ALIAS("sha256-padlock");