cryptodev_cipher.c

   1 /*
   2  * Driver for /dev/crypto device (aka CryptoDev)
   3  *
   4  * Copyright (c) 2010 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 "cryptodev_int.h"
  37
  38
  39 struct cryptodev_result {
  40         struct completion completion;
  41         int err;
  42 };
  43
  44 static void cryptodev_complete(struct crypto_async_request *req, int err)
  45 {
  46         struct cryptodev_result *res = req->data;
  47
  48         if (err == -EINPROGRESS)
  49                 return;
  50
  51         res->err = err;
  52         complete(&res->completion);
  53 }
  54
  55 int cryptodev_cipher_init(struct cipher_data *out, const char *alg_name,
  56                                 uint8_t *keyp, size_t keylen)
  57 {
  58         struct ablkcipher_alg *alg;
  59         int ret;
  60
  61         memset(out, 0, sizeof(*out));
  62
  63         out->async.s = crypto_alloc_ablkcipher(alg_name, 0, 0);
  64         if (unlikely(IS_ERR(out->async.s))) {
  65                 dprintk(1, KERN_DEBUG, "%s: Failed to load cipher %s\n",
  66                         __func__, alg_name);
  67                 return -EINVAL;
  68         }
  69
  70         alg = crypto_ablkcipher_alg(out->async.s);
  71
  72         if (alg != NULL) {
  73                 /* Was correct key length supplied? */
  74                 if (alg->max_keysize > 0 &&
  75                                 unlikely((keylen < alg->min_keysize) ||
  76                                         (keylen > alg->max_keysize))) {
  77                         dprintk(1, KERN_DEBUG,
  78                                 "Wrong keylen '%zu' for algorithm '%s'. \
  79                                 Use %u to %u.\n",
  80                                    keylen, alg_name, alg->min_keysize,
  81                                    alg->max_keysize);
  82                         ret = -EINVAL;
  83                         goto error;
  84                 }
  85         }
  86
  87         ret = crypto_ablkcipher_setkey(out->async.s, keyp, keylen);
  88         if (unlikely(ret)) {
  89                 dprintk(1, KERN_DEBUG, "Setting key failed for %s-%zu.\n",
  90                         alg_name, keylen*8);
  91                 ret = -EINVAL;
  92                 goto error;
  93         }
  94
  95         out->blocksize = crypto_ablkcipher_blocksize(out->async.s);
  96         out->ivsize = crypto_ablkcipher_ivsize(out->async.s);
  97         out->alignmask = crypto_ablkcipher_alignmask(out->async.s);
  98
  99         out->async.result = kmalloc(sizeof(*out->async.result), GFP_KERNEL);
 100         if (unlikely(!out->async.result)) {
 101                 ret = -ENOMEM;
 102                 goto error;
 103         }
 104
 105         memset(out->async.result, 0, sizeof(*out->async.result));
 106         init_completion(&out->async.result->completion);
 107
 108         out->async.request = ablkcipher_request_alloc(out->async.s, GFP_KERNEL);
 109         if (unlikely(!out->async.request)) {
 110                 dprintk(1, KERN_ERR, "error allocating async crypto request\n");
 111                 ret = -ENOMEM;
 112                 goto error;
 113         }
 114
 115         ablkcipher_request_set_callback(out->async.request,
 116                                         CRYPTO_TFM_REQ_MAY_BACKLOG,
 117                                         cryptodev_complete, out->async.result);
 118
 119         out->init = 1;
 120         return 0;
 121 error:
 122         if (out->async.request)
 123                 ablkcipher_request_free(out->async.request);
 124         kfree(out->async.result);
 125         if (out->async.s)
 126                 crypto_free_ablkcipher(out->async.s);
 127
 128         return ret;
 129 }
 130
 131 void cryptodev_cipher_deinit(struct cipher_data *cdata)
 132 {
 133         if (cdata->init) {
 134                 if (cdata->async.request)
 135                         ablkcipher_request_free(cdata->async.request);
 136                 kfree(cdata->async.result);
 137                 if (cdata->async.s)
 138                         crypto_free_ablkcipher(cdata->async.s);
 139
 140                 cdata->init = 0;
 141         }
 142 }
 143
 144 static inline int waitfor(struct cryptodev_result *cr, ssize_t ret)
 145 {
 146         switch (ret) {
 147         case 0:
 148                 break;
 149         case -EINPROGRESS:
 150         case -EBUSY:
 151                 wait_for_completion(&cr->completion);
 152                 /* At this point we known for sure the request has finished,
 153                  * because wait_for_completion above was not interruptible.
 154                  * This is important because otherwise hardware or driver
 155                  * might try to access memory which will be freed or reused for
 156                  * another request. */
 157
 158                 if (unlikely(cr->err)) {
 159                         dprintk(0, KERN_ERR, "error from async request: %d\n",
 160                                 cr->err);
 161                         return cr->err;
 162                 }
 163
 164                 break;
 165         default:
 166                 return ret;
 167         }
 168
 169         return 0;
 170 }
 171
 172 ssize_t cryptodev_cipher_encrypt(struct cipher_data *cdata,
 173                 const struct scatterlist *sg1, struct scatterlist *sg2,
 174                 size_t len)
 175 {
 176         int ret;
 177
 178         INIT_COMPLETION(cdata->async.result->completion);
 179         ablkcipher_request_set_crypt(cdata->async.request,
 180                         (struct scatterlist *)sg1, sg2,
 181                         len, cdata->async.iv);
 182         ret = crypto_ablkcipher_encrypt(cdata->async.request);
 183
 184         return waitfor(cdata->async.result, ret);
 185 }
 186
 187 ssize_t cryptodev_cipher_decrypt(struct cipher_data *cdata,
 188                 const struct scatterlist *sg1, struct scatterlist *sg2,
 189                 size_t len)
 190 {
 191         int ret;
 192
 193         INIT_COMPLETION(cdata->async.result->completion);
 194         ablkcipher_request_set_crypt(cdata->async.request,
 195                         (struct scatterlist *)sg1, sg2,
 196                         len, cdata->async.iv);
 197         ret = crypto_ablkcipher_decrypt(cdata->async.request);
 198
 199         return waitfor(cdata->async.result, ret);
 200 }
 201
 202 /* Hash functions */
 203
 204 int cryptodev_hash_init(struct hash_data *hdata, const char *alg_name,
 205                         int hmac_mode, void *mackey, size_t mackeylen)
 206 {
 207         int ret;
 208
 209         hdata->async.s = crypto_alloc_ahash(alg_name, 0, 0);
 210         if (unlikely(IS_ERR(hdata->async.s))) {
 211                 dprintk(1, KERN_DEBUG, "%s: Failed to load transform for %s\n",
 212                         __func__, alg_name);
 213                 return -EINVAL;
 214         }
 215
 216         /* Copy the key from user and set to TFM. */
 217         if (hmac_mode != 0) {
 218                 ret = crypto_ahash_setkey(hdata->async.s, mackey, mackeylen);
 219                 if (unlikely(ret)) {
 220                         dprintk(1, KERN_DEBUG,
 221                                 "Setting hmac key failed for %s-%zu.\n",
 222                                 alg_name, mackeylen*8);
 223                         ret = -EINVAL;
 224                         goto error;
 225                 }
 226         }
 227
 228         hdata->digestsize = crypto_ahash_digestsize(hdata->async.s);
 229         hdata->alignmask = crypto_ahash_alignmask(hdata->async.s);
 230
 231         hdata->async.result = kmalloc(sizeof(*hdata->async.result), GFP_KERNEL);
 232         if (unlikely(!hdata->async.result)) {
 233                 ret = -ENOMEM;
 234                 goto error;
 235         }
 236
 237         memset(hdata->async.result, 0, sizeof(*hdata->async.result));
 238         init_completion(&hdata->async.result->completion);
 239
 240         hdata->async.request = ahash_request_alloc(hdata->async.s, GFP_KERNEL);
 241         if (unlikely(!hdata->async.request)) {
 242                 dprintk(0, KERN_ERR, "error allocating async crypto request\n");
 243                 ret = -ENOMEM;
 244                 goto error;
 245         }
 246
 247         ahash_request_set_callback(hdata->async.request,
 248                         CRYPTO_TFM_REQ_MAY_BACKLOG,
 249                         cryptodev_complete, hdata->async.result);
 250
 251         ret = crypto_ahash_init(hdata->async.request);
 252         if (unlikely(ret)) {
 253                 dprintk(0, KERN_ERR, "error in crypto_hash_init()\n");
 254                 goto error_request;
 255         }
 256
 257         hdata->init = 1;
 258         return 0;
 259
 260 error_request:
 261         ahash_request_free(hdata->async.request);
 262 error:
 263         kfree(hdata->async.result);
 264         crypto_free_ahash(hdata->async.s);
 265         return ret;
 266 }
 267
 268 void cryptodev_hash_deinit(struct hash_data *hdata)
 269 {
 270         if (hdata->init) {
 271                 if (hdata->async.request)
 272                         ahash_request_free(hdata->async.request);
 273                 kfree(hdata->async.result);
 274                 if (hdata->async.s)
 275                         crypto_free_ahash(hdata->async.s);
 276                 hdata->init = 0;
 277         }
 278 }
 279
 280 int cryptodev_hash_reset(struct hash_data *hdata)
 281 {
 282         int ret;
 283
 284         ret = crypto_ahash_init(hdata->async.request);
 285         if (unlikely(ret)) {
 286                 dprintk(0, KERN_ERR, "error in crypto_hash_init()\n");
 287                 return ret;
 288         }
 289
 290         return 0;
 291
 292 }
 293
 294 ssize_t cryptodev_hash_update(struct hash_data *hdata,
 295                                 struct scatterlist *sg, size_t len)
 296 {
 297         int ret;
 298
 299         INIT_COMPLETION(hdata->async.result->completion);
 300         ahash_request_set_crypt(hdata->async.request, sg, NULL, len);
 301
 302         ret = crypto_ahash_update(hdata->async.request);
 303
 304         return waitfor(hdata->async.result, ret);
 305 }
 306
 307 int cryptodev_hash_final(struct hash_data *hdata, void* output)
 308 {
 309         int ret;
 310
 311         INIT_COMPLETION(hdata->async.result->completion);
 312         ahash_request_set_crypt(hdata->async.request, NULL, output, 0);
 313
 314         ret = crypto_ahash_final(hdata->async.request);
 315
 316         return waitfor(hdata->async.result, ret);
 317 }
 318