cryptlib.c

   1 /*
   2  * Driver for /dev/crypto device (aka CryptoDev)
   3  *
   4  * Copyright (c) 2010,2011 Nikos Mavrogiannopoulos <nmav@gnutls.org>
   5  * Portions Copyright (c) 2010 Michael Weiser
   6  * Portions Copyright (c) 2010 Phil Sutter
   7  *
   8  * This file is part of linux cryptodev.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  24  */
  25
  26 #include <linux/crypto.h>
  27 #include <linux/mm.h>
  28 #include <linux/highmem.h>
  29 #include <linux/ioctl.h>
  30 #include <linux/random.h>
  31 #include <linux/scatterlist.h>
  32 #include <linux/uaccess.h>
  33 #include <crypto/algapi.h>
  34 #include <crypto/hash.h>
  35 #include <crypto/cryptodev.h>
  36 #include <crypto/aead.h>
  37 #include "cryptodev_int.h"
  38
  39
  40 struct cryptodev_result {
  41         struct completion completion;
  42         int err;
  43 };
  44
  45 static void cryptodev_complete(struct crypto_async_request *req, int err)
  46 {
  47         struct cryptodev_result *res = req->data;
  48
  49         if (err == -EINPROGRESS)
  50                 return;
  51
  52         res->err = err;
  53         complete(&res->completion);
  54 }
  55
  56 int cryptodev_cipher_init(struct cipher_data *out, const char *alg_name,
  57                                 uint8_t *keyp, size_t keylen, int stream, int aead)
  58 {
  59         int ret;
  60
  61         memset(out, 0, sizeof(*out));
  62
  63         if (aead == 0) {
  64                 struct ablkcipher_alg *alg;
  65
  66                 out->async.s = crypto_alloc_ablkcipher(alg_name, 0, 0);
  67                 if (unlikely(IS_ERR(out->async.s))) {
  68                         dprintk(1, KERN_DEBUG, "%s: Failed to load cipher %s\n",
  69                                 __func__, alg_name);
  70                                 return -EINVAL;
  71                 }
  72
  73                 alg = crypto_ablkcipher_alg(out->async.s);
  74                 if (alg != NULL) {
  75                         /* Was correct key length supplied? */
  76                         if (alg->max_keysize > 0 &&
  77                                         unlikely((keylen < alg->min_keysize) ||
  78                                         (keylen > alg->max_keysize))) {
  79                                 dprintk(1, KERN_DEBUG,
  80                                         "Wrong keylen '%zu' for algorithm '%s'. \
  81                                         Use %u to %u.\n",
  82                                            keylen, alg_name, alg->min_keysize,
  83                                            alg->max_keysize);
  84                                 ret = -EINVAL;
  85                                 goto error;
  86                         }
  87                 }
  88
  89                 out->blocksize = crypto_ablkcipher_blocksize(out->async.s);
  90                 out->ivsize = crypto_ablkcipher_ivsize(out->async.s);
  91                 out->alignmask = crypto_ablkcipher_alignmask(out->async.s);
  92
  93                 ret = crypto_ablkcipher_setkey(out->async.s, keyp, keylen);
  94         } else {
  95                 out->async.as = crypto_alloc_aead(alg_name, 0, 0);
  96                 if (unlikely(IS_ERR(out->async.as))) {
  97                         dprintk(1, KERN_DEBUG, "%s: Failed to load cipher %s\n",
  98                                 __func__, alg_name);
  99                         return -EINVAL;
 100                 }
 101
 102                 out->blocksize = crypto_aead_blocksize(out->async.as);
 103                 out->ivsize = crypto_aead_ivsize(out->async.as);
 104                 out->alignmask = crypto_aead_alignmask(out->async.as);
 105
 106                 ret = crypto_aead_setkey(out->async.as, keyp, keylen);
 107         }
 108
 109         if (unlikely(ret)) {
 110                 dprintk(1, KERN_DEBUG, "Setting key failed for %s-%zu.\n",
 111                         alg_name, keylen*8);
 112                 ret = -EINVAL;
 113                 goto error;
 114         }
 115
 116         out->stream = stream;
 117         out->aead = aead;
 118
 119         out->async.result = kmalloc(sizeof(*out->async.result), GFP_KERNEL);
 120         if (unlikely(!out->async.result)) {
 121                 ret = -ENOMEM;
 122                 goto error;
 123         }
 124
 125         memset(out->async.result, 0, sizeof(*out->async.result));
 126         init_completion(&out->async.result->completion);
 127
 128         if (aead == 0) {
 129                 out->async.request = ablkcipher_request_alloc(out->async.s, GFP_KERNEL);
 130                 if (unlikely(!out->async.request)) {
 131                         dprintk(1, KERN_ERR, "error allocating async crypto request\n");
 132                         ret = -ENOMEM;
 133                         goto error;
 134                 }
 135
 136                 ablkcipher_request_set_callback(out->async.request,
 137                                         CRYPTO_TFM_REQ_MAY_BACKLOG,
 138                                         cryptodev_complete, out->async.result);
 139         } else {
 140                 out->async.arequest = aead_request_alloc(out->async.as, GFP_KERNEL);
 141                 if (unlikely(!out->async.arequest)) {
 142                         dprintk(1, KERN_ERR, "error allocating async crypto request\n");
 143                         ret = -ENOMEM;
 144                         goto error;
 145                 }
 146
 147                 aead_request_set_callback(out->async.arequest,
 148                                         CRYPTO_TFM_REQ_MAY_BACKLOG,
 149                                         cryptodev_complete, out->async.result);
 150         }
 151
 152         out->init = 1;
 153         return 0;
 154 error:
 155         if (aead == 0) {
 156                 if (out->async.request)
 157                         ablkcipher_request_free(out->async.request);
 158                 if (out->async.s)
 159                         crypto_free_ablkcipher(out->async.s);
 160         } else {
 161                 if (out->async.arequest)
 162                         aead_request_free(out->async.arequest);
 163                 if (out->async.s)
 164                         crypto_free_aead(out->async.as);
 165         }
 166         kfree(out->async.result);
 167
 168         return ret;
 169 }
 170
 171 void cryptodev_cipher_deinit(struct cipher_data *cdata)
 172 {
 173         if (cdata->init) {
 174                 if (cdata->aead == 0) {
 175                         if (cdata->async.request)
 176                                 ablkcipher_request_free(cdata->async.request);
 177                         if (cdata->async.s)
 178                                 crypto_free_ablkcipher(cdata->async.s);
 179                 } else {
 180                         if (cdata->async.arequest)
 181                                 aead_request_free(cdata->async.arequest);
 182                         if (cdata->async.as)
 183                                 crypto_free_aead(cdata->async.as);
 184                 }
 185
 186                 kfree(cdata->async.result);
 187                 cdata->init = 0;
 188         }
 189 }
 190
 191 static inline int waitfor(struct cryptodev_result *cr, ssize_t ret)
 192 {
 193         switch (ret) {
 194         case 0:
 195                 break;
 196         case -EINPROGRESS:
 197         case -EBUSY:
 198                 wait_for_completion(&cr->completion);
 199                 /* At this point we known for sure the request has finished,
 200                  * because wait_for_completion above was not interruptible.
 201                  * This is important because otherwise hardware or driver
 202                  * might try to access memory which will be freed or reused for
 203                  * another request. */
 204
 205                 if (unlikely(cr->err)) {
 206                         dprintk(0, KERN_ERR, "error from async request: %d\n",
 207                                 cr->err);
 208                         return cr->err;
 209                 }
 210
 211                 break;
 212         default:
 213                 return ret;
 214         }
 215
 216         return 0;
 217 }
 218
 219 ssize_t cryptodev_cipher_encrypt(struct cipher_data *cdata,
 220                 const struct scatterlist *src, struct scatterlist *dst,
 221                 size_t len)
 222 {
 223         int ret;
 224
 225         INIT_COMPLETION(cdata->async.result->completion);
 226
 227         if (cdata->aead == 0) {
 228                 ablkcipher_request_set_crypt(cdata->async.request,
 229                         (struct scatterlist *)src, dst,
 230                         len, cdata->async.iv);
 231                 ret = crypto_ablkcipher_encrypt(cdata->async.request);
 232         } else {
 233                 aead_request_set_crypt(cdata->async.arequest,
 234                         (struct scatterlist *)src, dst,
 235                         len, cdata->async.iv);
 236                 ret = crypto_aead_encrypt(cdata->async.arequest);
 237         }
 238
 239         return waitfor(cdata->async.result, ret);
 240 }
 241
 242 ssize_t cryptodev_cipher_decrypt(struct cipher_data *cdata,
 243                 const struct scatterlist *src, struct scatterlist *dst,
 244                 size_t len)
 245 {
 246         int ret;
 247
 248         INIT_COMPLETION(cdata->async.result->completion);
 249         if (cdata->aead == 0) {
 250                 ablkcipher_request_set_crypt(cdata->async.request,
 251                         (struct scatterlist *)src, dst,
 252                         len, cdata->async.iv);
 253                 ret = crypto_ablkcipher_decrypt(cdata->async.request);
 254         } else {
 255                 aead_request_set_crypt(cdata->async.arequest,
 256                         (struct scatterlist *)src, dst,
 257                         len, cdata->async.iv);
 258                 ret = crypto_aead_decrypt(cdata->async.arequest);
 259         }
 260
 261         return waitfor(cdata->async.result, ret);
 262 }
 263
 264 /* Hash functions */
 265
 266 int cryptodev_hash_init(struct hash_data *hdata, const char *alg_name,
 267                         int hmac_mode, void *mackey, size_t mackeylen)
 268 {
 269         int ret;
 270
 271         hdata->async.s = crypto_alloc_ahash(alg_name, 0, 0);
 272         if (unlikely(IS_ERR(hdata->async.s))) {
 273                 dprintk(1, KERN_DEBUG, "%s: Failed to load transform for %s\n",
 274                         __func__, alg_name);
 275                 return -EINVAL;
 276         }
 277
 278         /* Copy the key from user and set to TFM. */
 279         if (hmac_mode != 0) {
 280                 ret = crypto_ahash_setkey(hdata->async.s, mackey, mackeylen);
 281                 if (unlikely(ret)) {
 282                         dprintk(1, KERN_DEBUG,
 283                                 "Setting hmac key failed for %s-%zu.\n",
 284                                 alg_name, mackeylen*8);
 285                         ret = -EINVAL;
 286                         goto error;
 287                 }
 288         }
 289
 290         hdata->digestsize = crypto_ahash_digestsize(hdata->async.s);
 291         hdata->alignmask = crypto_ahash_alignmask(hdata->async.s);
 292
 293         hdata->async.result = kmalloc(sizeof(*hdata->async.result), GFP_KERNEL);
 294         if (unlikely(!hdata->async.result)) {
 295                 ret = -ENOMEM;
 296                 goto error;
 297         }
 298
 299         memset(hdata->async.result, 0, sizeof(*hdata->async.result));
 300         init_completion(&hdata->async.result->completion);
 301
 302         hdata->async.request = ahash_request_alloc(hdata->async.s, GFP_KERNEL);
 303         if (unlikely(!hdata->async.request)) {
 304                 dprintk(0, KERN_ERR, "error allocating async crypto request\n");
 305                 ret = -ENOMEM;
 306                 goto error;
 307         }
 308
 309         ahash_request_set_callback(hdata->async.request,
 310                         CRYPTO_TFM_REQ_MAY_BACKLOG,
 311                         cryptodev_complete, hdata->async.result);
 312
 313         ret = crypto_ahash_init(hdata->async.request);
 314         if (unlikely(ret)) {
 315                 dprintk(0, KERN_ERR, "error in crypto_hash_init()\n");
 316                 goto error_request;
 317         }
 318
 319         hdata->init = 1;
 320         return 0;
 321
 322 error_request:
 323         ahash_request_free(hdata->async.request);
 324 error:
 325         kfree(hdata->async.result);
 326         crypto_free_ahash(hdata->async.s);
 327         return ret;
 328 }
 329
 330 void cryptodev_hash_deinit(struct hash_data *hdata)
 331 {
 332         if (hdata->init) {
 333                 if (hdata->async.request)
 334                         ahash_request_free(hdata->async.request);
 335                 kfree(hdata->async.result);
 336                 if (hdata->async.s)
 337                         crypto_free_ahash(hdata->async.s);
 338                 hdata->init = 0;
 339         }
 340 }
 341
 342 int cryptodev_hash_reset(struct hash_data *hdata)
 343 {
 344         int ret;
 345
 346         ret = crypto_ahash_init(hdata->async.request);
 347         if (unlikely(ret)) {
 348                 dprintk(0, KERN_ERR, "error in crypto_hash_init()\n");
 349                 return ret;
 350         }
 351
 352         return 0;
 353
 354 }
 355
 356 ssize_t cryptodev_hash_update(struct hash_data *hdata,
 357                                 struct scatterlist *sg, size_t len)
 358 {
 359         int ret;
 360
 361         INIT_COMPLETION(hdata->async.result->completion);
 362         ahash_request_set_crypt(hdata->async.request, sg, NULL, len);
 363
 364         ret = crypto_ahash_update(hdata->async.request);
 365
 366         return waitfor(hdata->async.result, ret);
 367 }
 368
 369 int cryptodev_hash_final(struct hash_data *hdata, void* output)
 370 {
 371         int ret;
 372
 373         INIT_COMPLETION(hdata->async.result->completion);
 374         ahash_request_set_crypt(hdata->async.request, NULL, output, 0);
 375
 376         ret = crypto_ahash_final(hdata->async.request);
 377
 378         return waitfor(hdata->async.result, ret);
 379 }
 380