lustre/ptlrpc/gss/gss_sk_mech.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (C) 2013, 2015, Trustees of Indiana University
  24  *
  25  * Copyright (c) 2014, 2016, Intel Corporation.
  26  *
  27  * Author: Jeremy Filizetti <jfilizet@iu.edu>
  28  * Author: Andrew Korty <ajk@iu.edu>
  29  */
  30
  31 #define DEBUG_SUBSYSTEM S_SEC
  32 #include <linux/init.h>
  33 #include <linux/module.h>
  34 #include <linux/slab.h>
  35 #include <linux/crypto.h>
  36 #include <linux/mutex.h>
  37 #include <crypto/ctr.h>
  38
  39 #include <obd.h>
  40 #include <obd_class.h>
  41 #include <obd_support.h>
  42
  43 #include "gss_err.h"
  44 #include "gss_crypto.h"
  45 #include "gss_internal.h"
  46 #include "gss_api.h"
  47 #include "gss_asn1.h"
  48
  49 #define SK_INTERFACE_VERSION 1
  50 #define SK_MSG_VERSION 1
  51 #define SK_MIN_SIZE 8
  52 #define SK_IV_SIZE 16
  53
  54 /* Starting number for reverse contexts.  It is critical to security
  55  * that reverse contexts use a different range of numbers than regular
  56  * contexts because they are using the same key.  Therefore the IV/nonce
  57  * combination must be unique for them.  To accomplish this reverse contexts
  58  * use the the negative range of a 64-bit number and regular contexts use the
  59  * postive range.  If the same IV/nonce combination were reused it would leak
  60  * information about the plaintext. */
  61 #define SK_IV_REV_START (1ULL << 63)
  62
  63 struct sk_ctx {
  64         enum cfs_crypto_crypt_alg sc_crypt;
  65         enum cfs_crypto_hash_alg  sc_hmac;
  66         __u32                     sc_expire;
  67         __u32                     sc_host_random;
  68         __u32                     sc_peer_random;
  69         atomic64_t                sc_iv;
  70         rawobj_t                  sc_hmac_key;
  71         struct gss_keyblock       sc_session_kb;
  72 };
  73
  74 struct sk_hdr {
  75         __u64                   skh_version;
  76         __u64                   skh_iv;
  77 } __attribute__((packed));
  78
  79 /* The format of SK wire data is similar to that of RFC3686 ESP Payload
  80  * (section 3) except instead of just an IV there is a struct sk_hdr.
  81  * ---------------------------------------------------------------------
  82  * | struct sk_hdr | ciphertext (variable size) | HMAC (variable size) |
  83  * --------------------------------------------------------------------- */
  84 struct sk_wire {
  85         rawobj_t                skw_header;
  86         rawobj_t                skw_cipher;
  87         rawobj_t                skw_hmac;
  88 };
  89
  90 static inline unsigned long sk_block_mask(unsigned long len, int blocksize)
  91 {
  92         return (len + blocksize - 1) & (~(blocksize - 1));
  93 }
  94
  95 static int sk_fill_header(struct sk_ctx *skc, struct sk_hdr *skh)
  96 {
  97         __u64 tmp_iv;
  98         skh->skh_version = be64_to_cpu(SK_MSG_VERSION);
  99
 100         /* Always using inc_return so we don't use our initial numbers which
 101          * could be the reuse detecting numbers */
 102         tmp_iv = atomic64_inc_return(&skc->sc_iv);
 103         skh->skh_iv = be64_to_cpu(tmp_iv);
 104         if (tmp_iv == 0 || tmp_iv == SK_IV_REV_START) {
 105                 CERROR("Counter looped, connection must be reset to avoid "
 106                        "plaintext information\n");
 107                 return GSS_S_FAILURE;
 108         }
 109
 110         return GSS_S_COMPLETE;
 111 }
 112
 113 static int sk_verify_header(struct sk_hdr *skh)
 114 {
 115         if (cpu_to_be64(skh->skh_version) != SK_MSG_VERSION)
 116                 return GSS_S_DEFECTIVE_TOKEN;
 117
 118         return GSS_S_COMPLETE;
 119 }
 120
 121 void sk_construct_rfc3686_iv(__u8 *iv, __u32 nonce, __u64 partial_iv)
 122 {
 123         __u32 ctr = cpu_to_be32(1);
 124
 125         memcpy(iv, &nonce, CTR_RFC3686_NONCE_SIZE);
 126         iv += CTR_RFC3686_NONCE_SIZE;
 127         memcpy(iv, &partial_iv, CTR_RFC3686_IV_SIZE);
 128         iv += CTR_RFC3686_IV_SIZE;
 129         memcpy(iv, &ctr, sizeof(ctr));
 130 }
 131
 132 static int sk_fill_context(rawobj_t *inbuf, struct sk_ctx *skc)
 133 {
 134         char *ptr = inbuf->data;
 135         char *end = inbuf->data + inbuf->len;
 136         char sk_hmac[CRYPTO_MAX_ALG_NAME];
 137         char sk_crypt[CRYPTO_MAX_ALG_NAME];
 138         u32 tmp;
 139
 140         /* see sk_serialize_kctx() for format from userspace side */
 141         /*  1. Version */
 142         if (gss_get_bytes(&ptr, end, &tmp, sizeof(tmp))) {
 143                 CERROR("Failed to read shared key interface version\n");
 144                 return -1;
 145         }
 146         if (tmp != SK_INTERFACE_VERSION) {
 147                 CERROR("Invalid shared key interface version: %d\n", tmp);
 148                 return -1;
 149         }
 150
 151         /* 2. HMAC type */
 152         if (gss_get_bytes(&ptr, end, &sk_hmac, sizeof(sk_hmac))) {
 153                 CERROR("Failed to read HMAC algorithm type\n");
 154                 return -1;
 155         }
 156
 157         skc->sc_hmac = cfs_crypto_hash_alg(sk_hmac);
 158         if (skc->sc_hmac != CFS_HASH_ALG_NULL &&
 159             skc->sc_hmac != CFS_HASH_ALG_SHA256 &&
 160             skc->sc_hmac != CFS_HASH_ALG_SHA512) {
 161                 CERROR("Invalid hmac type: %s\n", sk_hmac);
 162                 return -1;
 163         }
 164
 165         /* 3. crypt type */
 166         if (gss_get_bytes(&ptr, end, &sk_crypt, sizeof(sk_crypt))) {
 167                 CERROR("Failed to read crypt algorithm type\n");
 168                 return -1;
 169         }
 170
 171         skc->sc_crypt = cfs_crypto_crypt_alg(sk_crypt);
 172         if (skc->sc_crypt == CFS_CRYPT_ALG_UNKNOWN) {
 173                 CERROR("Invalid crypt type: %s\n", sk_crypt);
 174                 return -1;
 175         }
 176
 177         /* 4. expiration time */
 178         if (gss_get_bytes(&ptr, end, &tmp, sizeof(tmp))) {
 179                 CERROR("Failed to read context expiration time\n");
 180                 return -1;
 181         }
 182         skc->sc_expire = tmp + ktime_get_real_seconds();
 183
 184         /* 5. host random is used as nonce for encryption */
 185         if (gss_get_bytes(&ptr, end, &skc->sc_host_random,
 186                           sizeof(skc->sc_host_random))) {
 187                 CERROR("Failed to read host random\n");
 188                 return -1;
 189         }
 190
 191         /* 6. peer random is used as nonce for decryption */
 192         if (gss_get_bytes(&ptr, end, &skc->sc_peer_random,
 193                           sizeof(skc->sc_peer_random))) {
 194                 CERROR("Failed to read peer random\n");
 195                 return -1;
 196         }
 197
 198         /* 7. HMAC key */
 199         if (gss_get_rawobj(&ptr, end, &skc->sc_hmac_key)) {
 200                 CERROR("Failed to read HMAC key\n");
 201                 return -1;
 202         }
 203         if (skc->sc_hmac_key.len <= SK_MIN_SIZE) {
 204                 CERROR("HMAC key must key must be larger than %d bytes\n",
 205                        SK_MIN_SIZE);
 206                 return -1;
 207         }
 208
 209         /* 8. Session key, can be empty if not using privacy mode */
 210         if (gss_get_rawobj(&ptr, end, &skc->sc_session_kb.kb_key)) {
 211                 CERROR("Failed to read session key\n");
 212                 return -1;
 213         }
 214
 215         return 0;
 216 }
 217
 218 static void sk_delete_context(struct sk_ctx *skc)
 219 {
 220         if (!skc)
 221                 return;
 222
 223         rawobj_free(&skc->sc_hmac_key);
 224         gss_keyblock_free(&skc->sc_session_kb);
 225         OBD_FREE_PTR(skc);
 226 }
 227
 228 static
 229 __u32 gss_import_sec_context_sk(rawobj_t *inbuf, struct gss_ctx *gss_context)
 230 {
 231         struct sk_ctx *skc;
 232         bool privacy = false;
 233
 234         if (inbuf == NULL || inbuf->data == NULL)
 235                 return GSS_S_FAILURE;
 236
 237         OBD_ALLOC_PTR(skc);
 238         if (!skc)
 239                 return GSS_S_FAILURE;
 240
 241         atomic64_set(&skc->sc_iv, 0);
 242
 243         if (sk_fill_context(inbuf, skc))
 244                 goto out_err;
 245
 246         /* Only privacy mode needs to initialize keys */
 247         if (skc->sc_session_kb.kb_key.len > 0) {
 248                 privacy = true;
 249                 if (gss_keyblock_init(&skc->sc_session_kb,
 250                                       cfs_crypto_crypt_name(skc->sc_crypt), 0))
 251                         goto out_err;
 252         }
 253
 254         gss_context->internal_ctx_id = skc;
 255         CDEBUG(D_SEC, "successfully imported sk%s context\n",
 256                privacy ? " (with privacy)" : "");
 257
 258         return GSS_S_COMPLETE;
 259
 260 out_err:
 261         sk_delete_context(skc);
 262         return GSS_S_FAILURE;
 263 }
 264
 265 static
 266 __u32 gss_copy_reverse_context_sk(struct gss_ctx *gss_context_old,
 267                                   struct gss_ctx *gss_context_new)
 268 {
 269         struct sk_ctx *skc_old = gss_context_old->internal_ctx_id;
 270         struct sk_ctx *skc_new;
 271
 272         OBD_ALLOC_PTR(skc_new);
 273         if (!skc_new)
 274                 return GSS_S_FAILURE;
 275
 276         skc_new->sc_hmac = skc_old->sc_hmac;
 277         skc_new->sc_crypt = skc_old->sc_crypt;
 278         skc_new->sc_expire = skc_old->sc_expire;
 279         skc_new->sc_host_random = skc_old->sc_host_random;
 280         skc_new->sc_peer_random = skc_old->sc_peer_random;
 281
 282         atomic64_set(&skc_new->sc_iv, SK_IV_REV_START);
 283
 284         if (rawobj_dup(&skc_new->sc_hmac_key, &skc_old->sc_hmac_key))
 285                 goto out_err;
 286         if (gss_keyblock_dup(&skc_new->sc_session_kb, &skc_old->sc_session_kb))
 287                 goto out_err;
 288
 289         /* Only privacy mode needs to initialize keys */
 290         if (skc_new->sc_session_kb.kb_key.len > 0)
 291                 if (gss_keyblock_init(&skc_new->sc_session_kb,
 292                                       cfs_crypto_crypt_name(skc_new->sc_crypt),
 293                                       0))
 294                         goto out_err;
 295
 296         gss_context_new->internal_ctx_id = skc_new;
 297         CDEBUG(D_SEC, "successfully copied reverse sk context\n");
 298
 299         return GSS_S_COMPLETE;
 300
 301 out_err:
 302         sk_delete_context(skc_new);
 303         return GSS_S_FAILURE;
 304 }
 305
 306 static
 307 __u32 gss_inquire_context_sk(struct gss_ctx *gss_context,
 308                              time64_t *endtime)
 309 {
 310         struct sk_ctx *skc = gss_context->internal_ctx_id;
 311
 312         *endtime = skc->sc_expire;
 313         return GSS_S_COMPLETE;
 314 }
 315
 316 static
 317 u32 sk_make_hmac(enum cfs_crypto_hash_alg algo, rawobj_t *key, int msg_count,
 318                  rawobj_t *msgs, int iov_count, lnet_kiov_t *iovs,
 319                  rawobj_t *token)
 320 {
 321         struct ahash_request *req;
 322         int rc2, rc;
 323
 324         req = cfs_crypto_hash_init(algo, key->data, key->len);
 325         if (IS_ERR(req)) {
 326                 rc = PTR_ERR(req);
 327                 goto out_init_failed;
 328         }
 329
 330         rc2 = gss_digest_hash(req, NULL, msg_count, msgs, iov_count, iovs,
 331                               token);
 332         rc = cfs_crypto_hash_final(req, key->data, &key->len);
 333         if (!rc && rc2)
 334                 rc = rc2;
 335 out_init_failed:
 336         return rc ? GSS_S_FAILURE : GSS_S_COMPLETE;
 337 }
 338
 339 static
 340 __u32 gss_get_mic_sk(struct gss_ctx *gss_context,
 341                      int message_count,
 342                      rawobj_t *messages,
 343                      int iov_count,
 344                      lnet_kiov_t *iovs,
 345                      rawobj_t *token)
 346 {
 347         struct sk_ctx *skc = gss_context->internal_ctx_id;
 348
 349         return sk_make_hmac(skc->sc_hmac,
 350                             &skc->sc_hmac_key, message_count, messages,
 351                             iov_count, iovs, token);
 352 }
 353
 354 static
 355 u32 sk_verify_hmac(enum cfs_crypto_hash_alg algo, rawobj_t *key,
 356                    int message_count, rawobj_t *messages,
 357                    int iov_count, lnet_kiov_t *iovs,
 358                    rawobj_t *token)
 359 {
 360         rawobj_t checksum = RAWOBJ_EMPTY;
 361         __u32 rc = GSS_S_FAILURE;
 362
 363         checksum.len = cfs_crypto_hash_digestsize(algo);
 364         if (token->len < checksum.len) {
 365                 CDEBUG(D_SEC, "Token received too short, expected %d "
 366                        "received %d\n", token->len, checksum.len);
 367                 return GSS_S_DEFECTIVE_TOKEN;
 368         }
 369
 370         OBD_ALLOC_LARGE(checksum.data, checksum.len);
 371         if (!checksum.data)
 372                 return rc;
 373
 374         if (sk_make_hmac(algo, key, message_count,
 375                          messages, iov_count, iovs, &checksum)) {
 376                 CDEBUG(D_SEC, "Failed to create checksum to validate\n");
 377                 goto cleanup;
 378         }
 379
 380         if (memcmp(token->data, checksum.data, checksum.len)) {
 381                 CERROR("checksum mismatch\n");
 382                 rc = GSS_S_BAD_SIG;
 383                 goto cleanup;
 384         }
 385
 386         rc = GSS_S_COMPLETE;
 387
 388 cleanup:
 389         OBD_FREE(checksum.data, checksum.len);
 390         return rc;
 391 }
 392
 393 /* sk_verify_bulk_hmac() differs slightly from sk_verify_hmac() because all
 394  * encrypted pages in the bulk descriptor are populated although we only need
 395  * to decrypt up to the number of bytes actually specified from the sender
 396  * (bd_nob) otherwise the calulated HMAC will be incorrect. */
 397 static
 398 u32 sk_verify_bulk_hmac(enum cfs_crypto_hash_alg sc_hmac, rawobj_t *key,
 399                         int msgcnt, rawobj_t *msgs, int iovcnt,
 400                         lnet_kiov_t *iovs, int iov_bytes, rawobj_t *token)
 401 {
 402         rawobj_t checksum = RAWOBJ_EMPTY;
 403         struct ahash_request *req;
 404         struct scatterlist sg[1];
 405         int rc = GSS_S_FAILURE;
 406         struct sg_table sgt;
 407         int bytes;
 408         int i;
 409
 410         checksum.len = cfs_crypto_hash_digestsize(sc_hmac);
 411         if (token->len < checksum.len) {
 412                 CDEBUG(D_SEC, "Token received too short, expected %d "
 413                        "received %d\n", token->len, checksum.len);
 414                 return GSS_S_DEFECTIVE_TOKEN;
 415         }
 416
 417         OBD_ALLOC_LARGE(checksum.data, checksum.len);
 418         if (!checksum.data)
 419                 return rc;
 420
 421         req = cfs_crypto_hash_init(sc_hmac, key->data, key->len);
 422         if (IS_ERR(req))
 423                 goto cleanup;
 424
 425         for (i = 0; i < msgcnt; i++) {
 426                 if (!msgs[i].len)
 427                         continue;
 428
 429                 rc = gss_setup_sgtable(&sgt, sg, msgs[i].data, msgs[i].len);
 430                 if (rc != 0)
 431                         goto hash_cleanup;
 432
 433                 ahash_request_set_crypt(req, sg, NULL, msgs[i].len);
 434                 rc = crypto_ahash_update(req);
 435                 if (rc) {
 436                         gss_teardown_sgtable(&sgt);
 437                         goto hash_cleanup;
 438                 }
 439
 440                 gss_teardown_sgtable(&sgt);
 441         }
 442
 443         for (i = 0; i < iovcnt && iov_bytes > 0; i++) {
 444                 if (iovs[i].kiov_len == 0)
 445                         continue;
 446
 447                 bytes = min_t(int, iov_bytes, iovs[i].kiov_len);
 448                 iov_bytes -= bytes;
 449
 450                 sg_init_table(sg, 1);
 451                 sg_set_page(&sg[0], iovs[i].kiov_page, bytes,
 452                             iovs[i].kiov_offset);
 453                 ahash_request_set_crypt(req, sg, NULL, bytes);
 454                 rc = crypto_ahash_update(req);
 455                 if (rc)
 456                         goto hash_cleanup;
 457         }
 458
 459         if (memcmp(token->data, checksum.data, checksum.len)) {
 460                 rc = GSS_S_BAD_SIG;
 461                 goto hash_cleanup;
 462         }
 463
 464         rc = GSS_S_COMPLETE;
 465
 466 hash_cleanup:
 467         cfs_crypto_hash_final(req, checksum.data, &checksum.len);
 468
 469 cleanup:
 470         OBD_FREE_LARGE(checksum.data, checksum.len);
 471
 472         return rc;
 473 }
 474
 475 static
 476 __u32 gss_verify_mic_sk(struct gss_ctx *gss_context,
 477                         int message_count,
 478                         rawobj_t *messages,
 479                         int iov_count,
 480                         lnet_kiov_t *iovs,
 481                         rawobj_t *token)
 482 {
 483         struct sk_ctx *skc = gss_context->internal_ctx_id;
 484
 485         return sk_verify_hmac(skc->sc_hmac, &skc->sc_hmac_key,
 486                               message_count, messages, iov_count, iovs, token);
 487 }
 488
 489 static
 490 __u32 gss_wrap_sk(struct gss_ctx *gss_context, rawobj_t *gss_header,
 491                     rawobj_t *message, int message_buffer_length,
 492                     rawobj_t *token)
 493 {
 494         struct sk_ctx *skc = gss_context->internal_ctx_id;
 495         size_t sht_bytes = cfs_crypto_hash_digestsize(skc->sc_hmac);
 496         struct sk_wire skw;
 497         struct sk_hdr skh;
 498         rawobj_t msgbufs[3];
 499         __u8 local_iv[SK_IV_SIZE];
 500         unsigned int blocksize;
 501
 502         LASSERT(skc->sc_session_kb.kb_tfm);
 503
 504         blocksize = crypto_blkcipher_blocksize(skc->sc_session_kb.kb_tfm);
 505         if (gss_add_padding(message, message_buffer_length, blocksize))
 506                 return GSS_S_FAILURE;
 507
 508         memset(token->data, 0, token->len);
 509
 510         if (sk_fill_header(skc, &skh) != GSS_S_COMPLETE)
 511                 return GSS_S_FAILURE;
 512
 513         skw.skw_header.data = token->data;
 514         skw.skw_header.len = sizeof(skh);
 515         memcpy(skw.skw_header.data, &skh, sizeof(skh));
 516
 517         sk_construct_rfc3686_iv(local_iv, skc->sc_host_random, skh.skh_iv);
 518         skw.skw_cipher.data = skw.skw_header.data + skw.skw_header.len;
 519         skw.skw_cipher.len = token->len - skw.skw_header.len - sht_bytes;
 520         if (gss_crypt_rawobjs(skc->sc_session_kb.kb_tfm, local_iv, 1, message,
 521                               &skw.skw_cipher, 1))
 522                 return GSS_S_FAILURE;
 523
 524         /* HMAC covers the SK header, GSS header, and ciphertext */
 525         msgbufs[0] = skw.skw_header;
 526         msgbufs[1] = *gss_header;
 527         msgbufs[2] = skw.skw_cipher;
 528
 529         skw.skw_hmac.data = skw.skw_cipher.data + skw.skw_cipher.len;
 530         skw.skw_hmac.len = sht_bytes;
 531         if (sk_make_hmac(skc->sc_hmac, &skc->sc_hmac_key,
 532                          3, msgbufs, 0, NULL, &skw.skw_hmac))
 533                 return GSS_S_FAILURE;
 534
 535         token->len = skw.skw_header.len + skw.skw_cipher.len + skw.skw_hmac.len;
 536
 537         return GSS_S_COMPLETE;
 538 }
 539
 540 static
 541 __u32 gss_unwrap_sk(struct gss_ctx *gss_context, rawobj_t *gss_header,
 542                       rawobj_t *token, rawobj_t *message)
 543 {
 544         struct sk_ctx *skc = gss_context->internal_ctx_id;
 545         size_t sht_bytes = cfs_crypto_hash_digestsize(skc->sc_hmac);
 546         struct sk_wire skw;
 547         struct sk_hdr *skh;
 548         rawobj_t msgbufs[3];
 549         __u8 local_iv[SK_IV_SIZE];
 550         unsigned int blocksize;
 551         int rc;
 552
 553         LASSERT(skc->sc_session_kb.kb_tfm);
 554
 555         if (token->len < sizeof(skh) + sht_bytes)
 556                 return GSS_S_DEFECTIVE_TOKEN;
 557
 558         skw.skw_header.data = token->data;
 559         skw.skw_header.len = sizeof(struct sk_hdr);
 560         skw.skw_cipher.data = skw.skw_header.data + skw.skw_header.len;
 561         skw.skw_cipher.len = token->len - skw.skw_header.len - sht_bytes;
 562         skw.skw_hmac.data = skw.skw_cipher.data + skw.skw_cipher.len;
 563         skw.skw_hmac.len = sht_bytes;
 564
 565         blocksize = crypto_blkcipher_blocksize(skc->sc_session_kb.kb_tfm);
 566         if (skw.skw_cipher.len % blocksize != 0)
 567                 return GSS_S_DEFECTIVE_TOKEN;
 568
 569         skh = (struct sk_hdr *)skw.skw_header.data;
 570         rc = sk_verify_header(skh);
 571         if (rc != GSS_S_COMPLETE)
 572                 return rc;
 573
 574         /* HMAC covers the SK header, GSS header, and ciphertext */
 575         msgbufs[0] = skw.skw_header;
 576         msgbufs[1] = *gss_header;
 577         msgbufs[2] = skw.skw_cipher;
 578         rc = sk_verify_hmac(skc->sc_hmac, &skc->sc_hmac_key, 3, msgbufs,
 579                             0, NULL, &skw.skw_hmac);
 580         if (rc)
 581                 return rc;
 582
 583         sk_construct_rfc3686_iv(local_iv, skc->sc_peer_random, skh->skh_iv);
 584         message->len = skw.skw_cipher.len;
 585         if (gss_crypt_rawobjs(skc->sc_session_kb.kb_tfm, local_iv,
 586                               1, &skw.skw_cipher, message, 0))
 587                 return GSS_S_FAILURE;
 588
 589         return GSS_S_COMPLETE;
 590 }
 591
 592 static
 593 __u32 gss_prep_bulk_sk(struct gss_ctx *gss_context,
 594                        struct ptlrpc_bulk_desc *desc)
 595 {
 596         struct sk_ctx *skc = gss_context->internal_ctx_id;
 597         int blocksize;
 598         int i;
 599
 600         LASSERT(skc->sc_session_kb.kb_tfm);
 601         blocksize = crypto_blkcipher_blocksize(skc->sc_session_kb.kb_tfm);
 602
 603         for (i = 0; i < desc->bd_iov_count; i++) {
 604                 if (BD_GET_KIOV(desc, i).kiov_offset & blocksize) {
 605                         CERROR("offset %d not blocksize aligned\n",
 606                                BD_GET_KIOV(desc, i).kiov_offset);
 607                         return GSS_S_FAILURE;
 608                 }
 609
 610                 BD_GET_ENC_KIOV(desc, i).kiov_offset =
 611                         BD_GET_KIOV(desc, i).kiov_offset;
 612                 BD_GET_ENC_KIOV(desc, i).kiov_len =
 613                         sk_block_mask(BD_GET_KIOV(desc, i).kiov_len, blocksize);
 614         }
 615
 616         return GSS_S_COMPLETE;
 617 }
 618
 619 static __u32 sk_encrypt_bulk(struct crypto_blkcipher *tfm, __u8 *iv,
 620                              struct ptlrpc_bulk_desc *desc, rawobj_t *cipher,
 621                              int adj_nob)
 622 {
 623         struct blkcipher_desc cdesc = {
 624                 .tfm = tfm,
 625                 .info = iv,
 626                 .flags = 0,
 627         };
 628         struct scatterlist ptxt;
 629         struct scatterlist ctxt;
 630         int blocksize;
 631         int i;
 632         int rc;
 633         int nob = 0;
 634
 635         blocksize = crypto_blkcipher_blocksize(tfm);
 636
 637         sg_init_table(&ptxt, 1);
 638         sg_init_table(&ctxt, 1);
 639
 640         for (i = 0; i < desc->bd_iov_count; i++) {
 641                 sg_set_page(&ptxt, BD_GET_KIOV(desc, i).kiov_page,
 642                             sk_block_mask(BD_GET_KIOV(desc, i).kiov_len,
 643                                           blocksize),
 644                             BD_GET_KIOV(desc, i).kiov_offset);
 645                 nob += ptxt.length;
 646
 647                 sg_set_page(&ctxt, BD_GET_ENC_KIOV(desc, i).kiov_page,
 648                             ptxt.length, ptxt.offset);
 649
 650                 BD_GET_ENC_KIOV(desc, i).kiov_offset = ctxt.offset;
 651                 BD_GET_ENC_KIOV(desc, i).kiov_len = ctxt.length;
 652
 653                 rc = crypto_blkcipher_encrypt_iv(&cdesc, &ctxt, &ptxt,
 654                                                  ptxt.length);
 655                 if (rc) {
 656                         CERROR("failed to encrypt page: %d\n", rc);
 657                         return rc;
 658                 }
 659         }
 660
 661         if (adj_nob)
 662                 desc->bd_nob = nob;
 663
 664         return 0;
 665 }
 666
 667 static __u32 sk_decrypt_bulk(struct crypto_blkcipher *tfm, __u8 *iv,
 668                              struct ptlrpc_bulk_desc *desc, rawobj_t *cipher,
 669                              int adj_nob)
 670 {
 671         struct blkcipher_desc cdesc = {
 672                 .tfm = tfm,
 673                 .info = iv,
 674                 .flags = 0,
 675         };
 676         struct scatterlist ptxt;
 677         struct scatterlist ctxt;
 678         int blocksize;
 679         int i;
 680         int rc;
 681         int pnob = 0;
 682         int cnob = 0;
 683
 684         sg_init_table(&ptxt, 1);
 685         sg_init_table(&ctxt, 1);
 686
 687         blocksize = crypto_blkcipher_blocksize(tfm);
 688         if (desc->bd_nob_transferred % blocksize != 0) {
 689                 CERROR("Transfer not a multiple of block size: %d\n",
 690                        desc->bd_nob_transferred);
 691                 return GSS_S_DEFECTIVE_TOKEN;
 692         }
 693
 694         for (i = 0; i < desc->bd_iov_count && cnob < desc->bd_nob_transferred;
 695              i++) {
 696                 lnet_kiov_t *piov = &BD_GET_KIOV(desc, i);
 697                 lnet_kiov_t *ciov = &BD_GET_ENC_KIOV(desc, i);
 698
 699                 if (ciov->kiov_offset % blocksize != 0 ||
 700                     ciov->kiov_len % blocksize != 0) {
 701                         CERROR("Invalid bulk descriptor vector\n");
 702                         return GSS_S_DEFECTIVE_TOKEN;
 703                 }
 704
 705                 /* Must adjust bytes here because we know the actual sizes after
 706                  * decryption.  Similar to what gss_cli_ctx_unwrap_bulk does for
 707                  * integrity only mode */
 708                 if (adj_nob) {
 709                         /* cipher text must not exceed transferred size */
 710                         if (ciov->kiov_len + cnob > desc->bd_nob_transferred)
 711                                 ciov->kiov_len =
 712                                         desc->bd_nob_transferred - cnob;
 713
 714                         piov->kiov_len = ciov->kiov_len;
 715
 716                         /* plain text must not exceed bulk's size */
 717                         if (ciov->kiov_len + pnob > desc->bd_nob)
 718                                 piov->kiov_len = desc->bd_nob - pnob;
 719                 } else {
 720                         /* Taken from krb5_decrypt since it was not verified
 721                          * whether or not LNET guarantees these */
 722                         if (ciov->kiov_len + cnob > desc->bd_nob_transferred ||
 723                             piov->kiov_len > ciov->kiov_len) {
 724                                 CERROR("Invalid decrypted length\n");
 725                                 return GSS_S_FAILURE;
 726                         }
 727                 }
 728
 729                 if (ciov->kiov_len == 0)
 730                         continue;
 731
 732                 sg_init_table(&ctxt, 1);
 733                 sg_set_page(&ctxt, ciov->kiov_page, ciov->kiov_len,
 734                             ciov->kiov_offset);
 735                 ptxt = ctxt;
 736
 737                 /* In the event the plain text size is not a multiple
 738                  * of blocksize we decrypt in place and copy the result
 739                  * after the decryption */
 740                 if (piov->kiov_len % blocksize == 0)
 741                         sg_assign_page(&ptxt, piov->kiov_page);
 742
 743                 rc = crypto_blkcipher_decrypt_iv(&cdesc, &ptxt, &ctxt,
 744                                                  ctxt.length);
 745                 if (rc) {
 746                         CERROR("Decryption failed for page: %d\n", rc);
 747                         return GSS_S_FAILURE;
 748                 }
 749
 750                 if (piov->kiov_len % blocksize != 0) {
 751                         memcpy(page_address(piov->kiov_page) +
 752                                piov->kiov_offset,
 753                                page_address(ciov->kiov_page) +
 754                                ciov->kiov_offset,
 755                                piov->kiov_len);
 756                 }
 757
 758                 cnob += ciov->kiov_len;
 759                 pnob += piov->kiov_len;
 760         }
 761
 762         /* if needed, clear up the rest unused iovs */
 763         if (adj_nob)
 764                 while (i < desc->bd_iov_count)
 765                         BD_GET_KIOV(desc, i++).kiov_len = 0;
 766
 767         if (unlikely(cnob != desc->bd_nob_transferred)) {
 768                 CERROR("%d cipher text transferred but only %d decrypted\n",
 769                        desc->bd_nob_transferred, cnob);
 770                 return GSS_S_FAILURE;
 771         }
 772
 773         if (unlikely(!adj_nob && pnob != desc->bd_nob)) {
 774                 CERROR("%d plain text expected but only %d received\n",
 775                        desc->bd_nob, pnob);
 776                 return GSS_S_FAILURE;
 777         }
 778
 779         return 0;
 780 }
 781
 782 static
 783 __u32 gss_wrap_bulk_sk(struct gss_ctx *gss_context,
 784                        struct ptlrpc_bulk_desc *desc, rawobj_t *token,
 785                        int adj_nob)
 786 {
 787         struct sk_ctx *skc = gss_context->internal_ctx_id;
 788         size_t sht_bytes = cfs_crypto_hash_digestsize(skc->sc_hmac);
 789         struct sk_wire skw;
 790         struct sk_hdr skh;
 791         __u8 local_iv[SK_IV_SIZE];
 792
 793         LASSERT(skc->sc_session_kb.kb_tfm);
 794
 795         memset(token->data, 0, token->len);
 796         if (sk_fill_header(skc, &skh) != GSS_S_COMPLETE)
 797                 return GSS_S_FAILURE;
 798
 799         skw.skw_header.data = token->data;
 800         skw.skw_header.len = sizeof(skh);
 801         memcpy(skw.skw_header.data, &skh, sizeof(skh));
 802
 803         sk_construct_rfc3686_iv(local_iv, skc->sc_host_random, skh.skh_iv);
 804         skw.skw_cipher.data = skw.skw_header.data + skw.skw_header.len;
 805         skw.skw_cipher.len = token->len - skw.skw_header.len - sht_bytes;
 806         if (sk_encrypt_bulk(skc->sc_session_kb.kb_tfm, local_iv,
 807                             desc, &skw.skw_cipher, adj_nob))
 808                 return GSS_S_FAILURE;
 809
 810         skw.skw_hmac.data = skw.skw_cipher.data + skw.skw_cipher.len;
 811         skw.skw_hmac.len = sht_bytes;
 812         if (sk_make_hmac(skc->sc_hmac, &skc->sc_hmac_key, 1, &skw.skw_cipher,
 813                          desc->bd_iov_count, GET_ENC_KIOV(desc), &skw.skw_hmac))
 814                 return GSS_S_FAILURE;
 815
 816         return GSS_S_COMPLETE;
 817 }
 818
 819 static
 820 __u32 gss_unwrap_bulk_sk(struct gss_ctx *gss_context,
 821                            struct ptlrpc_bulk_desc *desc,
 822                            rawobj_t *token, int adj_nob)
 823 {
 824         struct sk_ctx *skc = gss_context->internal_ctx_id;
 825         size_t sht_bytes = cfs_crypto_hash_digestsize(skc->sc_hmac);
 826         struct sk_wire skw;
 827         struct sk_hdr *skh;
 828         __u8 local_iv[SK_IV_SIZE];
 829         int rc;
 830
 831         LASSERT(skc->sc_session_kb.kb_tfm);
 832
 833         if (token->len < sizeof(skh) + sht_bytes)
 834                 return GSS_S_DEFECTIVE_TOKEN;
 835
 836         skw.skw_header.data = token->data;
 837         skw.skw_header.len = sizeof(struct sk_hdr);
 838         skw.skw_cipher.data = skw.skw_header.data + skw.skw_header.len;
 839         skw.skw_cipher.len = token->len - skw.skw_header.len - sht_bytes;
 840         skw.skw_hmac.data = skw.skw_cipher.data + skw.skw_cipher.len;
 841         skw.skw_hmac.len = sht_bytes;
 842
 843         skh = (struct sk_hdr *)skw.skw_header.data;
 844         rc = sk_verify_header(skh);
 845         if (rc != GSS_S_COMPLETE)
 846                 return rc;
 847
 848         rc = sk_verify_bulk_hmac(skc->sc_hmac, &skc->sc_hmac_key, 1,
 849                                  &skw.skw_cipher, desc->bd_iov_count,
 850                                  GET_ENC_KIOV(desc), desc->bd_nob,
 851                                  &skw.skw_hmac);
 852         if (rc)
 853                 return rc;
 854
 855         sk_construct_rfc3686_iv(local_iv, skc->sc_peer_random, skh->skh_iv);
 856         rc = sk_decrypt_bulk(skc->sc_session_kb.kb_tfm, local_iv,
 857                              desc, &skw.skw_cipher, adj_nob);
 858         if (rc)
 859                 return rc;
 860
 861         return GSS_S_COMPLETE;
 862 }
 863
 864 static
 865 void gss_delete_sec_context_sk(void *internal_context)
 866 {
 867         struct sk_ctx *sk_context = internal_context;
 868         sk_delete_context(sk_context);
 869 }
 870
 871 int gss_display_sk(struct gss_ctx *gss_context, char *buf, int bufsize)
 872 {
 873         return snprintf(buf, bufsize, "sk");
 874 }
 875
 876 static struct gss_api_ops gss_sk_ops = {
 877         .gss_import_sec_context     = gss_import_sec_context_sk,
 878         .gss_copy_reverse_context   = gss_copy_reverse_context_sk,
 879         .gss_inquire_context        = gss_inquire_context_sk,
 880         .gss_get_mic                = gss_get_mic_sk,
 881         .gss_verify_mic             = gss_verify_mic_sk,
 882         .gss_wrap                   = gss_wrap_sk,
 883         .gss_unwrap                 = gss_unwrap_sk,
 884         .gss_prep_bulk              = gss_prep_bulk_sk,
 885         .gss_wrap_bulk              = gss_wrap_bulk_sk,
 886         .gss_unwrap_bulk            = gss_unwrap_bulk_sk,
 887         .gss_delete_sec_context     = gss_delete_sec_context_sk,
 888         .gss_display                = gss_display_sk,
 889 };
 890
 891 static struct subflavor_desc gss_sk_sfs[] = {
 892         {
 893                 .sf_subflavor   = SPTLRPC_SUBFLVR_SKN,
 894                 .sf_qop         = 0,
 895                 .sf_service     = SPTLRPC_SVC_NULL,
 896                 .sf_name        = "skn"
 897         },
 898         {
 899                 .sf_subflavor   = SPTLRPC_SUBFLVR_SKA,
 900                 .sf_qop         = 0,
 901                 .sf_service     = SPTLRPC_SVC_AUTH,
 902                 .sf_name        = "ska"
 903         },
 904         {
 905                 .sf_subflavor   = SPTLRPC_SUBFLVR_SKI,
 906                 .sf_qop         = 0,
 907                 .sf_service     = SPTLRPC_SVC_INTG,
 908                 .sf_name        = "ski"
 909         },
 910         {
 911                 .sf_subflavor   = SPTLRPC_SUBFLVR_SKPI,
 912                 .sf_qop         = 0,
 913                 .sf_service     = SPTLRPC_SVC_PRIV,
 914                 .sf_name        = "skpi"
 915         },
 916 };
 917
 918 static struct gss_api_mech gss_sk_mech = {
 919         /* .gm_owner uses default NULL value for THIS_MODULE */
 920         .gm_name        = "sk",
 921         .gm_oid         = (rawobj_t) {
 922                 .len = 12,
 923                 .data = "\053\006\001\004\001\311\146\215\126\001\000\001",
 924         },
 925         .gm_ops         = &gss_sk_ops,
 926         .gm_sf_num      = 4,
 927         .gm_sfs         = gss_sk_sfs,
 928 };
 929
 930 int __init init_sk_module(void)
 931 {
 932         int status;
 933
 934         status = lgss_mech_register(&gss_sk_mech);
 935         if (status)
 936                 CERROR("Failed to register sk gss mechanism!\n");
 937
 938         return status;
 939 }
 940
 941 void cleanup_sk_module(void)
 942 {
 943         lgss_mech_unregister(&gss_sk_mech);
 944 }