authenc.c

   1 /*
   2  * Driver for /dev/crypto device (aka CryptoDev)
   3  *
   4  * Copyright (c) 2011, 2012 OpenSSL Software Foundation, Inc.
   5  *
   6  * Author: Nikos Mavrogiannopoulos
   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 /*
  27  * This file handles the AEAD part of /dev/crypto.
  28  *
  29  */
  30
  31 #include <crypto/hash.h>
  32 #include <linux/crypto.h>
  33 #include <linux/mm.h>
  34 #include <linux/highmem.h>
  35 #include <linux/ioctl.h>
  36 #include <linux/random.h>
  37 #include <linux/syscalls.h>
  38 #include <linux/pagemap.h>
  39 #include <linux/poll.h>
  40 #include <linux/uaccess.h>
  41 #include <crypto/cryptodev.h>
  42 #include <crypto/scatterwalk.h>
  43 #include <linux/scatterlist.h>
  44 #include "cryptodev_int.h"
  45 #include "zc.h"
  46 #include "util.h"
  47 #include "cryptlib.h"
  48 #include "version.h"
  49
  50
  51 /* make caop->dst available in scatterlist.
  52  * (caop->src is assumed to be equal to caop->dst)
  53  */
  54 static int get_userbuf_tls(struct csession *ses, struct kernel_crypt_auth_op *kcaop,
  55                         struct scatterlist **dst_sg)
  56 {
  57         int pagecount = 0;
  58         struct crypt_auth_op *caop = &kcaop->caop;
  59         int rc;
  60
  61         if (caop->dst == NULL)
  62                 return -EINVAL;
  63
  64         if (ses->alignmask) {
  65                 if (!IS_ALIGNED((unsigned long)caop->dst, ses->alignmask))
  66                         dprintk(2, KERN_WARNING, "%s: careful - source address %lx is not %d byte aligned\n",
  67                                 __func__, (unsigned long)caop->dst, ses->alignmask + 1);
  68         }
  69
  70         if (kcaop->dst_len == 0) {
  71                 dprintk(1, KERN_WARNING, "Destination length cannot be zero\n");
  72                 return -EINVAL;
  73         }
  74
  75         pagecount = PAGECOUNT(caop->dst, kcaop->dst_len);
  76
  77         ses->used_pages = pagecount;
  78         ses->readonly_pages = 0;
  79
  80         rc = adjust_sg_array(ses, pagecount);
  81         if (rc)
  82                 return rc;
  83
  84         rc = __get_userbuf(caop->dst, kcaop->dst_len, 1, pagecount,
  85                            ses->pages, ses->sg, kcaop->task, kcaop->mm);
  86         if (unlikely(rc)) {
  87                 dprintk(1, KERN_ERR,
  88                         "failed to get user pages for data input\n");
  89                 return -EINVAL;
  90         }
  91
  92         (*dst_sg) = ses->sg;
  93
  94         return 0;
  95 }
  96
  97
  98 #define MAX_SRTP_AUTH_DATA_DIFF 256
  99
 100 /* Makes caop->auth_src available as scatterlist.
 101  * It also provides a pointer to caop->dst, which however,
 102  * is assumed to be within the caop->auth_src buffer. If not
 103  * (if their difference exceeds MAX_SRTP_AUTH_DATA_DIFF) it
 104  * returns error.
 105  */
 106 static int get_userbuf_srtp(struct csession *ses, struct kernel_crypt_auth_op *kcaop,
 107                         struct scatterlist **auth_sg, struct scatterlist **dst_sg)
 108 {
 109         int pagecount, diff;
 110         int auth_pagecount = 0;
 111         struct crypt_auth_op *caop = &kcaop->caop;
 112         int rc;
 113
 114         if (caop->dst == NULL && caop->auth_src == NULL) {
 115                 dprintk(1, KERN_ERR, "dst and auth_src cannot be both null\n");
 116                 return -EINVAL;
 117         }
 118
 119         if (ses->alignmask) {
 120                 if (!IS_ALIGNED((unsigned long)caop->dst, ses->alignmask))
 121                         dprintk(2, KERN_WARNING, "%s: careful - source address %lx is not %d byte aligned\n",
 122                                 __func__, (unsigned long)caop->dst, ses->alignmask + 1);
 123                 if (!IS_ALIGNED((unsigned long)caop->auth_src, ses->alignmask))
 124                         dprintk(2, KERN_WARNING, "%s: careful - source address %lx is not %d byte aligned\n",
 125                                 __func__, (unsigned long)caop->auth_src, ses->alignmask + 1);
 126         }
 127
 128         if (unlikely(kcaop->dst_len == 0 || caop->auth_len == 0)) {
 129                 dprintk(1, KERN_WARNING, "Destination length cannot be zero\n");
 130                 return -EINVAL;
 131         }
 132
 133         /* Note that in SRTP auth data overlap with data to be encrypted (dst)
 134          */
 135
 136         auth_pagecount = PAGECOUNT(caop->auth_src, caop->auth_len);
 137         diff = (int)(caop->src - caop->auth_src);
 138         if (diff > MAX_SRTP_AUTH_DATA_DIFF || diff < 0) {
 139                 dprintk(1, KERN_WARNING, "auth_src must overlap with src (diff: %d).\n", diff);
 140                 return -EINVAL;
 141         }
 142
 143         pagecount = auth_pagecount;
 144
 145         rc = adjust_sg_array(ses, pagecount*2); /* double pages to have pages for dst(=auth_src) */
 146         if (rc) {
 147                 dprintk(1, KERN_ERR, "cannot adjust sg array\n");
 148                 return rc;
 149         }
 150
 151         rc = __get_userbuf(caop->auth_src, caop->auth_len, 1, auth_pagecount,
 152                            ses->pages, ses->sg, kcaop->task, kcaop->mm);
 153         if (unlikely(rc)) {
 154                 dprintk(1, KERN_ERR,
 155                         "failed to get user pages for data input\n");
 156                 return -EINVAL;
 157         }
 158
 159         ses->used_pages = pagecount;
 160         ses->readonly_pages = 0;
 161
 162         (*auth_sg) = ses->sg;
 163
 164         (*dst_sg) = ses->sg + auth_pagecount;
 165         sg_init_table(*dst_sg, auth_pagecount);
 166         sg_copy(ses->sg, (*dst_sg), caop->auth_len);
 167         (*dst_sg) = sg_advance(*dst_sg, diff);
 168         if (*dst_sg == NULL) {
 169                 release_user_pages(ses);
 170                 dprintk(1, KERN_ERR,
 171                         "failed to get enough pages for auth data\n");
 172                 return -EINVAL;
 173         }
 174
 175         return 0;
 176 }
 177
 178 static int fill_kcaop_from_caop(struct kernel_crypt_auth_op *kcaop, struct fcrypt *fcr)
 179 {
 180         struct crypt_auth_op *caop = &kcaop->caop;
 181         struct csession *ses_ptr;
 182         int ret;
 183
 184         /* this also enters ses_ptr->sem */
 185         ses_ptr = crypto_get_session_by_sid(fcr, caop->ses);
 186         if (unlikely(!ses_ptr)) {
 187                 dprintk(1, KERN_ERR, "invalid session ID=0x%08X\n", caop->ses);
 188                 return -EINVAL;
 189         }
 190
 191         if (caop->flags & COP_FLAG_AEAD_TLS_TYPE || caop->flags & COP_FLAG_AEAD_SRTP_TYPE) {
 192                 if (caop->src != caop->dst) {
 193                         dprintk(1, KERN_ERR,
 194                                 "Non-inplace encryption and decryption is not efficient and not implemented\n");
 195                         ret = -EINVAL;
 196                         goto out_unlock;
 197                 }
 198         }
 199
 200         if (caop->tag_len == 0)
 201                 caop->tag_len = ses_ptr->hdata.digestsize;
 202
 203         kcaop->ivlen = caop->iv ? ses_ptr->cdata.ivsize : 0;
 204
 205         if (caop->flags & COP_FLAG_AEAD_TLS_TYPE)
 206                 kcaop->dst_len = caop->len + ses_ptr->cdata.blocksize /* pad */ + caop->tag_len;
 207         else
 208                 kcaop->dst_len = caop->len;
 209
 210         kcaop->task = current;
 211         kcaop->mm = current->mm;
 212
 213         if (caop->iv) {
 214                 ret = copy_from_user(kcaop->iv, caop->iv, kcaop->ivlen);
 215                 if (unlikely(ret)) {
 216                         dprintk(1, KERN_ERR,
 217                                 "error copying IV (%d bytes), copy_from_user returned %d for address %lx\n",
 218                                 kcaop->ivlen, ret, (unsigned long)caop->iv);
 219                         ret = -EFAULT;
 220                         goto out_unlock;
 221                 }
 222         }
 223
 224         ret = 0;
 225
 226 out_unlock:
 227         crypto_put_session(ses_ptr);
 228         return ret;
 229
 230 }
 231
 232 static int fill_caop_from_kcaop(struct kernel_crypt_auth_op *kcaop, struct fcrypt *fcr)
 233 {
 234         int ret;
 235
 236         kcaop->caop.len = kcaop->dst_len;
 237
 238         if (kcaop->ivlen && kcaop->caop.flags & COP_FLAG_WRITE_IV) {
 239                 ret = copy_to_user(kcaop->caop.iv,
 240                                 kcaop->iv, kcaop->ivlen);
 241                 if (unlikely(ret)) {
 242                         dprintk(1, KERN_ERR, "Error in copying to userspace\n");
 243                         return -EFAULT;
 244                 }
 245         }
 246         return 0;
 247 }
 248
 249
 250 int kcaop_from_user(struct kernel_crypt_auth_op *kcaop,
 251                         struct fcrypt *fcr, void __user *arg)
 252 {
 253         if (unlikely(copy_from_user(&kcaop->caop, arg, sizeof(kcaop->caop)))) {
 254                 dprintk(1, KERN_ERR, "Error in copying from userspace\n");
 255                 return -EFAULT;
 256         }
 257
 258         return fill_kcaop_from_caop(kcaop, fcr);
 259 }
 260
 261 int kcaop_to_user(struct kernel_crypt_auth_op *kcaop,
 262                 struct fcrypt *fcr, void __user *arg)
 263 {
 264         int ret;
 265
 266         ret = fill_caop_from_kcaop(kcaop, fcr);
 267         if (unlikely(ret)) {
 268                 dprintk(1, KERN_ERR, "fill_caop_from_kcaop\n");
 269                 return ret;
 270         }
 271
 272         if (unlikely(copy_to_user(arg, &kcaop->caop, sizeof(kcaop->caop)))) {
 273                 dprintk(1, KERN_ERR, "Error in copying to userspace\n");
 274                 return -EFAULT;
 275         }
 276         return 0;
 277 }
 278
 279 static void copy_tls_hash( struct scatterlist *dst_sg, int len, void* hash, int hash_len)
 280 {
 281         scatterwalk_map_and_copy(hash, dst_sg, len, hash_len, 1);
 282 }
 283
 284 static void read_tls_hash( struct scatterlist *dst_sg, int len, void* hash, int hash_len)
 285 {
 286         scatterwalk_map_and_copy(hash, dst_sg, len-hash_len, hash_len, 0);
 287 }
 288
 289 static int pad_record( struct scatterlist *dst_sg, int len, int block_size)
 290 {
 291         uint8_t pad[block_size];
 292         int pad_size = block_size - (len % block_size);
 293
 294         memset(pad, pad_size-1, pad_size);
 295
 296         scatterwalk_map_and_copy(pad, dst_sg, len, pad_size, 1);
 297
 298         return pad_size;
 299 }
 300
 301 static int verify_tls_record_pad( struct scatterlist *dst_sg, int len, int block_size)
 302 {
 303         uint8_t pad[256]; /* the maximum allowed */
 304         uint8_t pad_size;
 305         int i;
 306
 307         scatterwalk_map_and_copy(&pad_size, dst_sg, len-1, 1, 0);
 308
 309         if (pad_size+1 > len) {
 310                 dprintk(1, KERN_ERR, "Pad size: %d\n", pad_size);
 311                 return -EBADMSG;
 312         }
 313
 314         scatterwalk_map_and_copy(pad, dst_sg, len-pad_size-1, pad_size+1, 0);
 315
 316         for (i=0;i<pad_size;i++)
 317                 if (pad[i] != pad_size) {
 318                         dprintk(1, KERN_ERR, "Pad size: %d, pad: %d\n", pad_size, (int)pad[i]);
 319                         return -EBADMSG;
 320                 }
 321
 322         return pad_size+1;
 323 }
 324
 325 /* Authenticate and encrypt the TLS way (also perform padding).
 326  * During decryption it verifies the pad and tag and returns -EBADMSG on error.
 327  */
 328 static int
 329 tls_auth_n_crypt(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop,
 330                  struct scatterlist *auth_sg, uint32_t auth_len,
 331                  struct scatterlist *dst_sg, uint32_t len)
 332 {
 333         int ret, fail = 0;
 334         struct crypt_auth_op *caop = &kcaop->caop;
 335         uint8_t vhash[AALG_MAX_RESULT_LEN];
 336         uint8_t hash_output[AALG_MAX_RESULT_LEN];
 337
 338         /* TLS authenticates the plaintext except for the padding.
 339          */
 340         if (caop->op == COP_ENCRYPT) {
 341                 if (ses_ptr->hdata.init != 0) {
 342                         if (auth_len > 0) {
 343                                 ret = cryptodev_hash_update(&ses_ptr->hdata,
 344                                                                 auth_sg, auth_len);
 345                                 if (unlikely(ret)) {
 346                                         dprintk(0, KERN_ERR, "cryptodev_hash_update: %d\n", ret);
 347                                         return ret;
 348                                 }
 349                         }
 350
 351                         if (len > 0) {
 352                                 ret = cryptodev_hash_update(&ses_ptr->hdata,
 353                                                                 dst_sg, len);
 354                                 if (unlikely(ret)) {
 355                                         dprintk(0, KERN_ERR, "cryptodev_hash_update: %d\n", ret);
 356                                         return ret;
 357                                 }
 358                         }
 359
 360                         ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output);
 361                         if (unlikely(ret)) {
 362                                 dprintk(0, KERN_ERR, "cryptodev_hash_final: %d\n", ret);
 363                                 return ret;
 364                         }
 365
 366                         copy_tls_hash( dst_sg, len, hash_output, caop->tag_len);
 367                         len += caop->tag_len;
 368                 }
 369
 370                 if (ses_ptr->cdata.init != 0) {
 371                         if (ses_ptr->cdata.blocksize > 1) {
 372                                 ret = pad_record(dst_sg, len, ses_ptr->cdata.blocksize);
 373                                 len += ret;
 374                         }
 375
 376                         ret = cryptodev_cipher_encrypt(&ses_ptr->cdata,
 377                                                         dst_sg, dst_sg, len);
 378                         if (unlikely(ret)) {
 379                                 dprintk(0, KERN_ERR, "cryptodev_cipher_encrypt: %d\n", ret);
 380                                 return ret;
 381                         }
 382                 }
 383         } else {
 384                 if (ses_ptr->cdata.init != 0) {
 385                         ret = cryptodev_cipher_decrypt(&ses_ptr->cdata,
 386                                                         dst_sg, dst_sg, len);
 387
 388                         if (unlikely(ret)) {
 389                                 dprintk(0, KERN_ERR, "cryptodev_cipher_decrypt: %d\n", ret);
 390                                 return ret;
 391                         }
 392
 393                         if (ses_ptr->cdata.blocksize > 1) {
 394                                 ret = verify_tls_record_pad(dst_sg, len, ses_ptr->cdata.blocksize);
 395                                 if (unlikely(ret < 0)) {
 396                                         dprintk(2, KERN_ERR, "verify_record_pad: %d\n", ret);
 397                                         fail = 1;
 398                                 } else {
 399                                         len -= ret;
 400                                 }
 401                         }
 402                 }
 403
 404                 if (ses_ptr->hdata.init != 0) {
 405                         if (unlikely(caop->tag_len > sizeof(vhash) || caop->tag_len > len)) {
 406                                 dprintk(1, KERN_ERR, "Illegal tag len size\n");
 407                                 return -EINVAL;
 408                         }
 409
 410                         read_tls_hash( dst_sg, len, vhash, caop->tag_len);
 411                         len -= caop->tag_len;
 412
 413                         if (auth_len > 0) {
 414                                 ret = cryptodev_hash_update(&ses_ptr->hdata,
 415                                                                 auth_sg, auth_len);
 416                                 if (unlikely(ret)) {
 417                                         dprintk(0, KERN_ERR, "cryptodev_hash_update: %d\n", ret);
 418                                         return ret;
 419                                 }
 420                         }
 421
 422                         if (len > 0) {
 423                                 ret = cryptodev_hash_update(&ses_ptr->hdata,
 424                                                                         dst_sg, len);
 425                                 if (unlikely(ret)) {
 426                                         dprintk(0, KERN_ERR, "cryptodev_hash_update: %d\n", ret);
 427                                         return ret;
 428                                 }
 429                         }
 430
 431                         ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output);
 432                         if (unlikely(ret)) {
 433                                 dprintk(0, KERN_ERR, "cryptodev_hash_final: %d\n", ret);
 434                                 return ret;
 435                         }
 436
 437                         if (memcmp(vhash, hash_output, caop->tag_len) != 0 || fail != 0) {
 438                                 dprintk(2, KERN_ERR, "MAC verification failed (tag_len: %d)\n", caop->tag_len);
 439                                 return -EBADMSG;
 440                         }
 441                 }
 442         }
 443         kcaop->dst_len = len;
 444         return 0;
 445 }
 446
 447 /* Authenticate and encrypt the SRTP way. During decryption
 448  * it verifies the tag and returns -EBADMSG on error.
 449  */
 450 static int
 451 srtp_auth_n_crypt(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop,
 452                   struct scatterlist *auth_sg, uint32_t auth_len,
 453                   struct scatterlist *dst_sg, uint32_t len)
 454 {
 455         int ret, fail = 0;
 456         struct crypt_auth_op *caop = &kcaop->caop;
 457         uint8_t vhash[AALG_MAX_RESULT_LEN];
 458         uint8_t hash_output[AALG_MAX_RESULT_LEN];
 459
 460         /* SRTP authenticates the encrypted data.
 461          */
 462         if (caop->op == COP_ENCRYPT) {
 463                 if (ses_ptr->cdata.init != 0) {
 464                         ret = cryptodev_cipher_encrypt(&ses_ptr->cdata,
 465                                                         dst_sg, dst_sg, len);
 466                         if (unlikely(ret)) {
 467                                 dprintk(0, KERN_ERR, "cryptodev_cipher_encrypt: %d\n", ret);
 468                                 return ret;
 469                         }
 470                 }
 471
 472                 if (ses_ptr->hdata.init != 0) {
 473                         if (auth_len > 0) {
 474                                 ret = cryptodev_hash_update(&ses_ptr->hdata,
 475                                                                 auth_sg, auth_len);
 476                                 if (unlikely(ret)) {
 477                                         dprintk(0, KERN_ERR, "cryptodev_hash_update: %d\n", ret);
 478                                         return ret;
 479                                 }
 480                         }
 481
 482                         ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output);
 483                         if (unlikely(ret)) {
 484                                 dprintk(0, KERN_ERR, "cryptodev_hash_final: %d\n", ret);
 485                                 return ret;
 486                         }
 487
 488                         if (unlikely(copy_to_user(caop->tag, hash_output, caop->tag_len))) {
 489                                 return -EFAULT;
 490                         }
 491                 }
 492
 493         } else {
 494                 if (ses_ptr->hdata.init != 0) {
 495                         if (unlikely(caop->tag_len > sizeof(vhash) || caop->tag_len > len)) {
 496                                 dprintk(1, KERN_ERR, "Illegal tag len size\n");
 497                                 return -EINVAL;
 498                         }
 499
 500                         if (unlikely(copy_from_user(vhash, caop->tag, caop->tag_len))) {
 501                                 return -EFAULT;
 502                         }
 503
 504                         ret = cryptodev_hash_update(&ses_ptr->hdata,
 505                                                         auth_sg, auth_len);
 506                         if (unlikely(ret)) {
 507                                 dprintk(0, KERN_ERR, "cryptodev_hash_update: %d\n", ret);
 508                                 return ret;
 509                         }
 510
 511                         ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output);
 512                         if (unlikely(ret)) {
 513                                 dprintk(0, KERN_ERR, "cryptodev_hash_final: %d\n", ret);
 514                                 return ret;
 515                         }
 516
 517                         if (memcmp(vhash, hash_output, caop->tag_len) != 0 || fail != 0) {
 518                                 dprintk(2, KERN_ERR, "MAC verification failed\n");
 519                                 return -EBADMSG;
 520                         }
 521                 }
 522
 523                 if (ses_ptr->cdata.init != 0) {
 524                         ret = cryptodev_cipher_decrypt(&ses_ptr->cdata,
 525                                                         dst_sg, dst_sg, len);
 526
 527                         if (unlikely(ret)) {
 528                                 dprintk(0, KERN_ERR, "cryptodev_cipher_decrypt: %d\n", ret);
 529                                 return ret;
 530                         }
 531                 }
 532
 533         }
 534         kcaop->dst_len = len;
 535         return 0;
 536 }
 537
 538 /* Typical AEAD (i.e. GCM) encryption/decryption.
 539  * During decryption the tag is verified.
 540  */
 541 static int
 542 auth_n_crypt(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop,
 543                   struct scatterlist *auth_sg, uint32_t auth_len,
 544                   struct scatterlist *src_sg,
 545                   struct scatterlist *dst_sg, uint32_t len)
 546 {
 547         int ret;
 548         struct crypt_auth_op *caop = &kcaop->caop;
 549         int max_tag_len;
 550
 551         max_tag_len = cryptodev_cipher_get_tag_size(&ses_ptr->cdata);
 552         if (unlikely(caop->tag_len > max_tag_len)) {
 553                 dprintk(0, KERN_ERR, "Illegal tag length: %d\n", caop->tag_len);
 554                 return -EINVAL;
 555         }
 556
 557         if (caop->tag_len)
 558                 cryptodev_cipher_set_tag_size(&ses_ptr->cdata, caop->tag_len);
 559         else
 560                 caop->tag_len = max_tag_len;
 561
 562         if (caop->op == COP_ENCRYPT) {
 563                 if (auth_len > 0)
 564                         cryptodev_cipher_auth(&ses_ptr->cdata, auth_sg, auth_len);
 565                 else /* for some reason we _have_ to call that */
 566                         cryptodev_cipher_auth(&ses_ptr->cdata, NULL, 0);
 567
 568                 ret = cryptodev_cipher_encrypt(&ses_ptr->cdata,
 569                                                 src_sg, dst_sg, len);
 570                 if (unlikely(ret)) {
 571                         dprintk(0, KERN_ERR, "cryptodev_cipher_encrypt: %d\n", ret);
 572                         return ret;
 573                 }
 574                 kcaop->dst_len = len + caop->tag_len;
 575                 caop->tag = caop->dst + len;
 576         } else {
 577                 if (auth_len > 0)
 578                         cryptodev_cipher_auth(&ses_ptr->cdata, auth_sg, auth_len);
 579
 580                 ret = cryptodev_cipher_decrypt(&ses_ptr->cdata,
 581                                                 src_sg, dst_sg, len);
 582
 583                 if (unlikely(ret)) {
 584                         dprintk(0, KERN_ERR, "cryptodev_cipher_decrypt: %d\n", ret);
 585                         return ret;
 586                 }
 587                 kcaop->dst_len = len - caop->tag_len;
 588                 caop->tag = caop->dst + len - caop->tag_len;
 589         }
 590
 591         return 0;
 592 }
 593
 594 /* This is the main crypto function - zero-copy edition */
 595 static int
 596 __crypto_auth_run_zc(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop)
 597 {
 598         struct scatterlist *dst_sg, *auth_sg, *src_sg;
 599         struct crypt_auth_op *caop = &kcaop->caop;
 600         int ret = 0;
 601
 602         if (caop->flags & COP_FLAG_AEAD_SRTP_TYPE) {
 603                 if (unlikely(ses_ptr->cdata.init != 0 &&
 604                         (ses_ptr->cdata.stream == 0 || ses_ptr->cdata.aead != 0)))
 605                 {
 606                         dprintk(0, KERN_ERR, "Only stream modes are allowed in SRTP mode (but not AEAD)\n");
 607                         return -EINVAL;
 608                 }
 609
 610                 ret = get_userbuf_srtp(ses_ptr, kcaop, &auth_sg, &dst_sg);
 611                 if (unlikely(ret)) {
 612                         dprintk(1, KERN_ERR, "get_userbuf_srtp(): Error getting user pages.\n");
 613                         return ret;
 614                 }
 615
 616                 ret = srtp_auth_n_crypt(ses_ptr, kcaop, auth_sg, caop->auth_len,
 617                            dst_sg, caop->len);
 618         } else { /* TLS and normal cases. Here auth data are usually small
 619                   * so we just copy them to a free page, instead of trying
 620                   * to map them.
 621                   */
 622                 unsigned char* auth_buf = NULL;
 623                 struct scatterlist tmp;
 624
 625                 if (unlikely(caop->auth_len > PAGE_SIZE)) {
 626                         dprintk(1, KERN_ERR, "auth data len is excessive.\n");
 627                         return -EINVAL;
 628                 }
 629
 630                 auth_buf = (char *)__get_free_page(GFP_KERNEL);
 631                 if (unlikely(!auth_buf)) {
 632                         dprintk(1, KERN_ERR, "unable to get a free page.\n");
 633                         return -ENOMEM;
 634                 }
 635
 636                 if (caop->auth_src && caop->auth_len > 0) {
 637                         if (unlikely(copy_from_user(auth_buf, caop->auth_src, caop->auth_len))) {
 638                                 dprintk(1, KERN_ERR, "unable to copy auth data from userspace.\n");
 639                                 ret = -EFAULT;
 640                                 goto fail;
 641                         }
 642
 643                         sg_init_one(&tmp, auth_buf, caop->auth_len);
 644                         auth_sg = &tmp;
 645                 } else {
 646                         auth_sg = NULL;
 647                 }
 648
 649                 if (caop->flags & COP_FLAG_AEAD_TLS_TYPE && ses_ptr->cdata.aead == 0) {
 650                         ret = get_userbuf_tls(ses_ptr, kcaop, &dst_sg);
 651                         if (unlikely(ret)) {
 652                                 dprintk(1, KERN_ERR, "get_userbuf_tls(): Error getting user pages.\n");
 653                                 goto fail;
 654                         }
 655
 656                         ret = tls_auth_n_crypt(ses_ptr, kcaop, auth_sg, caop->auth_len,
 657                                    dst_sg, caop->len);
 658                 } else {
 659                         int dst_len;
 660
 661                         if (unlikely(ses_ptr->cdata.init == 0 ||
 662                                         ses_ptr->cdata.stream == 0 ||
 663                                         ses_ptr->cdata.aead == 0))
 664                         {
 665                                 dprintk(0, KERN_ERR, "Only stream and AEAD ciphers are allowed for authenc\n");
 666                                 ret = -EINVAL;
 667                                 goto fail;
 668                         }
 669
 670                         if (caop->op == COP_ENCRYPT) dst_len = caop->len + cryptodev_cipher_get_tag_size(&ses_ptr->cdata);
 671                         else dst_len = caop->len - cryptodev_cipher_get_tag_size(&ses_ptr->cdata);
 672
 673                         ret = get_userbuf(ses_ptr, caop->src, caop->len, caop->dst, dst_len,
 674                                           kcaop->task, kcaop->mm, &src_sg, &dst_sg);
 675                         if (unlikely(ret)) {
 676                                 dprintk(1, KERN_ERR, "get_userbuf(): Error getting user pages.\n");
 677                                 goto fail;
 678                         }
 679
 680                         ret = auth_n_crypt(ses_ptr, kcaop, auth_sg, caop->auth_len,
 681                                            src_sg, dst_sg, caop->len);
 682                 }
 683
 684 fail:
 685                 free_page((unsigned long)auth_buf);
 686         }
 687
 688         release_user_pages(ses_ptr);
 689         return ret;
 690 }
 691
 692
 693 int crypto_auth_run(struct fcrypt *fcr, struct kernel_crypt_auth_op *kcaop)
 694 {
 695         struct csession *ses_ptr;
 696         struct crypt_auth_op *caop = &kcaop->caop;
 697         int ret;
 698
 699         if (unlikely(caop->op != COP_ENCRYPT && caop->op != COP_DECRYPT)) {
 700                 dprintk(1, KERN_DEBUG, "invalid operation op=%u\n", caop->op);
 701                 return -EINVAL;
 702         }
 703
 704         /* this also enters ses_ptr->sem */
 705         ses_ptr = crypto_get_session_by_sid(fcr, caop->ses);
 706         if (unlikely(!ses_ptr)) {
 707                 dprintk(1, KERN_ERR, "invalid session ID=0x%08X\n", caop->ses);
 708                 return -EINVAL;
 709         }
 710
 711         if (unlikely(ses_ptr->cdata.init == 0)) {
 712                 dprintk(1, KERN_ERR, "cipher context not initialized\n");
 713                 ret = -EINVAL;
 714                 goto out_unlock;
 715         }
 716
 717         /* If we have a hash/mac handle reset its state */
 718         if (ses_ptr->hdata.init != 0) {
 719                 ret = cryptodev_hash_reset(&ses_ptr->hdata);
 720                 if (unlikely(ret)) {
 721                         dprintk(1, KERN_ERR,
 722                                 "error in cryptodev_hash_reset()\n");
 723                         goto out_unlock;
 724                 }
 725         }
 726
 727         cryptodev_cipher_set_iv(&ses_ptr->cdata, kcaop->iv,
 728                                 min(ses_ptr->cdata.ivsize, kcaop->ivlen));
 729
 730         if (likely(caop->len || caop->auth_len)) {
 731                 ret = __crypto_auth_run_zc(ses_ptr, kcaop);
 732                 if (unlikely(ret)) {
 733                         dprintk(1, KERN_ERR,
 734                                 "error in __crypto_auth_run_zc()\n");
 735                         goto out_unlock;
 736                 }
 737         } else {
 738                 dprintk(1, KERN_ERR,
 739                         "Do not have auth data nor other data.\n");
 740                 ret = -EINVAL;
 741                 goto out_unlock;
 742         }
 743
 744         ret = 0;
 745
 746         cryptodev_cipher_get_iv(&ses_ptr->cdata, kcaop->iv,
 747                                 min(ses_ptr->cdata.ivsize, kcaop->ivlen));
 748
 749 out_unlock:
 750         crypto_put_session(ses_ptr);
 751         return ret;
 752 }