fs/ceph/auth_x.c

   1
   2 #include "ceph_debug.h"
   3
   4 #include <linux/err.h>
   5 #include <linux/module.h>
   6 #include <linux/random.h>
   7
   8 #include "auth_x.h"
   9 #include "auth_x_protocol.h"
  10 #include "crypto.h"
  11 #include "auth.h"
  12 #include "decode.h"
  13
  14 struct kmem_cache *ceph_x_ticketbuf_cachep;
  15
  16 #define TEMP_TICKET_BUF_LEN     256
  17
  18 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
  19
  20 static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
  21 {
  22         struct ceph_x_info *xi = ac->private;
  23         int need;
  24
  25         ceph_x_validate_tickets(ac, &need);
  26         dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
  27              ac->want_keys, need, xi->have_keys);
  28         return (ac->want_keys & xi->have_keys) == ac->want_keys;
  29 }
  30
  31 static int ceph_x_encrypt_buflen(int ilen)
  32 {
  33         return sizeof(struct ceph_x_encrypt_header) + ilen + 16 +
  34                 sizeof(u32);
  35 }
  36
  37 static int ceph_x_encrypt(struct ceph_crypto_key *secret,
  38                           void *ibuf, int ilen, void *obuf, size_t olen)
  39 {
  40         struct ceph_x_encrypt_header head = {
  41                 .struct_v = 1,
  42                 .magic = cpu_to_le64(CEPHX_ENC_MAGIC)
  43         };
  44         size_t len = olen - sizeof(u32);
  45         int ret;
  46
  47         ret = ceph_encrypt2(secret, obuf + sizeof(u32), &len,
  48                             &head, sizeof(head), ibuf, ilen);
  49         if (ret)
  50                 return ret;
  51         ceph_encode_32(&obuf, len);
  52         return len + sizeof(u32);
  53 }
  54
  55 static int ceph_x_decrypt(struct ceph_crypto_key *secret,
  56                           void **p, void *end, void *obuf, size_t olen)
  57 {
  58         struct ceph_x_encrypt_header head;
  59         size_t head_len = sizeof(head);
  60         int len, ret;
  61
  62         len = ceph_decode_32(p);
  63         if (*p + len > end)
  64                 return -EINVAL;
  65
  66         dout("ceph_x_decrypt len %d\n", len);
  67         ret = ceph_decrypt2(secret, &head, &head_len, obuf, &olen,
  68                             *p, len);
  69         if (ret)
  70                 return ret;
  71         if (head.struct_v != 1 || le64_to_cpu(head.magic) != CEPHX_ENC_MAGIC)
  72                 return -EPERM;
  73         *p += len;
  74         return olen;
  75 }
  76
  77 /*
  78  * get existing (or insert new) ticket handler
  79  */
  80 struct ceph_x_ticket_handler *get_ticket_handler(struct ceph_auth_client *ac,
  81                                                  int service)
  82 {
  83         struct ceph_x_ticket_handler *th;
  84         struct ceph_x_info *xi = ac->private;
  85         struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
  86
  87         while (*p) {
  88                 parent = *p;
  89                 th = rb_entry(parent, struct ceph_x_ticket_handler, node);
  90                 if (service < th->service)
  91                         p = &(*p)->rb_left;
  92                 else if (service > th->service)
  93                         p = &(*p)->rb_right;
  94                 else
  95                         return th;
  96         }
  97
  98         /* add it */
  99         th = kzalloc(sizeof(*th), GFP_NOFS);
 100         if (!th)
 101                 return ERR_PTR(-ENOMEM);
 102         th->service = service;
 103         rb_link_node(&th->node, parent, p);
 104         rb_insert_color(&th->node, &xi->ticket_handlers);
 105         return th;
 106 }
 107
 108 static void remove_ticket_handler(struct ceph_auth_client *ac,
 109                                   struct ceph_x_ticket_handler *th)
 110 {
 111         struct ceph_x_info *xi = ac->private;
 112
 113         dout("remove_ticket_handler %p %d\n", th, th->service);
 114         rb_erase(&th->node, &xi->ticket_handlers);
 115         ceph_crypto_key_destroy(&th->session_key);
 116         if (th->ticket_blob)
 117                 ceph_buffer_put(th->ticket_blob);
 118         kfree(th);
 119 }
 120
 121 static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
 122                                     struct ceph_crypto_key *secret,
 123                                     void *buf, void *end)
 124 {
 125         struct ceph_x_info *xi = ac->private;
 126         int num;
 127         void *p = buf;
 128         int ret;
 129         char *dbuf;
 130         char *ticket_buf;
 131         u8 struct_v;
 132
 133         dbuf = kmem_cache_alloc(ceph_x_ticketbuf_cachep, GFP_NOFS | GFP_ATOMIC);
 134         if (!dbuf)
 135                 return -ENOMEM;
 136
 137         ret = -ENOMEM;
 138         ticket_buf = kmem_cache_alloc(ceph_x_ticketbuf_cachep,
 139                                       GFP_NOFS | GFP_ATOMIC);
 140         if (!ticket_buf)
 141                 goto out_dbuf;
 142
 143         ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
 144         struct_v = ceph_decode_8(&p);
 145         if (struct_v != 1)
 146                 goto bad;
 147         num = ceph_decode_32(&p);
 148         dout("%d tickets\n", num);
 149         while (num--) {
 150                 int type;
 151                 u8 struct_v;
 152                 struct ceph_x_ticket_handler *th;
 153                 void *dp, *dend;
 154                 int dlen;
 155                 char is_enc;
 156                 struct timespec validity;
 157                 struct ceph_crypto_key old_key;
 158                 void *tp, *tpend;
 159                 struct ceph_timespec new_validity;
 160                 struct ceph_crypto_key new_session_key;
 161                 struct ceph_buffer *new_ticket_blob;
 162                 unsigned long new_expires, new_renew_after;
 163                 u64 new_secret_id;
 164
 165                 ceph_decode_need(&p, end, sizeof(u32) + 1, bad);
 166
 167                 type = ceph_decode_32(&p);
 168                 dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
 169
 170                 struct_v = ceph_decode_8(&p);
 171                 if (struct_v != 1)
 172                         goto bad;
 173
 174                 th = get_ticket_handler(ac, type);
 175                 if (IS_ERR(th)) {
 176                         ret = PTR_ERR(th);
 177                         goto out;
 178                 }
 179
 180                 /* blob for me */
 181                 dlen = ceph_x_decrypt(secret, &p, end, dbuf,
 182                                       TEMP_TICKET_BUF_LEN);
 183                 if (dlen <= 0) {
 184                         ret = dlen;
 185                         goto out;
 186                 }
 187                 dout(" decrypted %d bytes\n", dlen);
 188                 dend = dbuf + dlen;
 189                 dp = dbuf;
 190
 191                 struct_v = ceph_decode_8(&dp);
 192                 if (struct_v != 1)
 193                         goto bad;
 194
 195                 memcpy(&old_key, &th->session_key, sizeof(old_key));
 196                 ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
 197                 if (ret)
 198                         goto out;
 199
 200                 ceph_decode_copy(&dp, &new_validity, sizeof(new_validity));
 201                 ceph_decode_timespec(&validity, &new_validity);
 202                 new_expires = get_seconds() + validity.tv_sec;
 203                 new_renew_after = new_expires - (validity.tv_sec / 4);
 204                 dout(" expires=%lu renew_after=%lu\n", new_expires,
 205                      new_renew_after);
 206
 207                 /* ticket blob for service */
 208                 ceph_decode_8_safe(&p, end, is_enc, bad);
 209                 tp = ticket_buf;
 210                 if (is_enc) {
 211                         /* encrypted */
 212                         dout(" encrypted ticket\n");
 213                         dlen = ceph_x_decrypt(&old_key, &p, end, ticket_buf,
 214                                               TEMP_TICKET_BUF_LEN);
 215                         if (dlen < 0) {
 216                                 ret = dlen;
 217                                 goto out;
 218                         }
 219                         dlen = ceph_decode_32(&tp);
 220                 } else {
 221                         /* unencrypted */
 222                         ceph_decode_32_safe(&p, end, dlen, bad);
 223                         ceph_decode_need(&p, end, dlen, bad);
 224                         ceph_decode_copy(&p, ticket_buf, dlen);
 225                 }
 226                 tpend = tp + dlen;
 227                 dout(" ticket blob is %d bytes\n", dlen);
 228                 ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
 229                 struct_v = ceph_decode_8(&tp);
 230                 new_secret_id = ceph_decode_64(&tp);
 231                 ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
 232                 if (ret)
 233                         goto out;
 234
 235                 /* all is well, update our ticket */
 236                 ceph_crypto_key_destroy(&th->session_key);
 237                 if (th->ticket_blob)
 238                         ceph_buffer_put(th->ticket_blob);
 239                 th->session_key = new_session_key;
 240                 th->ticket_blob = new_ticket_blob;
 241                 th->validity = new_validity;
 242                 th->secret_id = new_secret_id;
 243                 th->expires = new_expires;
 244                 th->renew_after = new_renew_after;
 245                 dout(" got ticket service %d (%s) secret_id %lld len %d\n",
 246                      type, ceph_entity_type_name(type), th->secret_id,
 247                      (int)th->ticket_blob->vec.iov_len);
 248                 xi->have_keys |= th->service;
 249         }
 250
 251         ret = 0;
 252 out:
 253         kmem_cache_free(ceph_x_ticketbuf_cachep, ticket_buf);
 254 out_dbuf:
 255         kmem_cache_free(ceph_x_ticketbuf_cachep, dbuf);
 256         return ret;
 257
 258 bad:
 259         ret = -EINVAL;
 260         goto out;
 261 }
 262
 263 static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
 264                                    struct ceph_x_ticket_handler *th,
 265                                    struct ceph_x_authorizer *au)
 266 {
 267         int maxlen;
 268         struct ceph_x_authorize_a *msg_a;
 269         struct ceph_x_authorize_b msg_b;
 270         void *p, *end;
 271         int ret;
 272         int ticket_blob_len =
 273                 (th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
 274
 275         dout("build_authorizer for %s %p\n",
 276              ceph_entity_type_name(th->service), au);
 277
 278         maxlen = sizeof(*msg_a) + sizeof(msg_b) +
 279                 ceph_x_encrypt_buflen(ticket_blob_len);
 280         dout("  need len %d\n", maxlen);
 281         if (au->buf && au->buf->alloc_len < maxlen) {
 282                 ceph_buffer_put(au->buf);
 283                 au->buf = NULL;
 284         }
 285         if (!au->buf) {
 286                 au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
 287                 if (!au->buf)
 288                         return -ENOMEM;
 289         }
 290         au->service = th->service;
 291
 292         msg_a = au->buf->vec.iov_base;
 293         msg_a->struct_v = 1;
 294         msg_a->global_id = cpu_to_le64(ac->global_id);
 295         msg_a->service_id = cpu_to_le32(th->service);
 296         msg_a->ticket_blob.struct_v = 1;
 297         msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
 298         msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
 299         if (ticket_blob_len) {
 300                 memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
 301                        th->ticket_blob->vec.iov_len);
 302         }
 303         dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
 304              le64_to_cpu(msg_a->ticket_blob.secret_id));
 305
 306         p = msg_a + 1;
 307         p += ticket_blob_len;
 308         end = au->buf->vec.iov_base + au->buf->vec.iov_len;
 309
 310         get_random_bytes(&au->nonce, sizeof(au->nonce));
 311         msg_b.struct_v = 1;
 312         msg_b.nonce = cpu_to_le64(au->nonce);
 313         ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b),
 314                              p, end - p);
 315         if (ret < 0)
 316                 goto out_buf;
 317         p += ret;
 318         au->buf->vec.iov_len = p - au->buf->vec.iov_base;
 319         dout(" built authorizer nonce %llx len %d\n", au->nonce,
 320              (int)au->buf->vec.iov_len);
 321         BUG_ON(au->buf->vec.iov_len > maxlen);
 322         return 0;
 323
 324 out_buf:
 325         ceph_buffer_put(au->buf);
 326         au->buf = NULL;
 327         return ret;
 328 }
 329
 330 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
 331                                 void **p, void *end)
 332 {
 333         ceph_decode_need(p, end, 1 + sizeof(u64), bad);
 334         ceph_encode_8(p, 1);
 335         ceph_encode_64(p, th->secret_id);
 336         if (th->ticket_blob) {
 337                 const char *buf = th->ticket_blob->vec.iov_base;
 338                 u32 len = th->ticket_blob->vec.iov_len;
 339
 340                 ceph_encode_32_safe(p, end, len, bad);
 341                 ceph_encode_copy_safe(p, end, buf, len, bad);
 342         } else {
 343                 ceph_encode_32_safe(p, end, 0, bad);
 344         }
 345
 346         return 0;
 347 bad:
 348         return -ERANGE;
 349 }
 350
 351 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
 352 {
 353         int want = ac->want_keys;
 354         struct ceph_x_info *xi = ac->private;
 355         int service;
 356
 357         *pneed = ac->want_keys & ~(xi->have_keys);
 358
 359         for (service = 1; service <= want; service <<= 1) {
 360                 struct ceph_x_ticket_handler *th;
 361
 362                 if (!(ac->want_keys & service))
 363                         continue;
 364
 365                 if (*pneed & service)
 366                         continue;
 367
 368                 th = get_ticket_handler(ac, service);
 369
 370                 if (!th) {
 371                         *pneed |= service;
 372                         continue;
 373                 }
 374
 375                 if (get_seconds() >= th->renew_after)
 376                         *pneed |= service;
 377                 if (get_seconds() >= th->expires)
 378                         xi->have_keys &= ~service;
 379         }
 380 }
 381
 382
 383 static int ceph_x_build_request(struct ceph_auth_client *ac,
 384                                 void *buf, void *end)
 385 {
 386         struct ceph_x_info *xi = ac->private;
 387         int need;
 388         struct ceph_x_request_header *head = buf;
 389         int ret;
 390         struct ceph_x_ticket_handler *th =
 391                 get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
 392
 393         ceph_x_validate_tickets(ac, &need);
 394
 395         dout("build_request want %x have %x need %x\n",
 396              ac->want_keys, xi->have_keys, need);
 397
 398         if (need & CEPH_ENTITY_TYPE_AUTH) {
 399                 struct ceph_x_authenticate *auth = (void *)(head + 1);
 400                 void *p = auth + 1;
 401                 struct ceph_x_challenge_blob tmp;
 402                 char tmp_enc[40];
 403                 u64 *u;
 404
 405                 if (p > end)
 406                         return -ERANGE;
 407
 408                 dout(" get_auth_session_key\n");
 409                 head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
 410
 411                 /* encrypt and hash */
 412                 get_random_bytes(&auth->client_challenge, sizeof(u64));
 413                 tmp.client_challenge = auth->client_challenge;
 414                 tmp.server_challenge = cpu_to_le64(xi->server_challenge);
 415                 ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp),
 416                                      tmp_enc, sizeof(tmp_enc));
 417                 if (ret < 0)
 418                         return ret;
 419
 420                 auth->struct_v = 1;
 421                 auth->key = 0;
 422                 for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++)
 423                         auth->key ^= *u;
 424                 dout(" server_challenge %llx client_challenge %llx key %llx\n",
 425                      xi->server_challenge, le64_to_cpu(auth->client_challenge),
 426                      le64_to_cpu(auth->key));
 427
 428                 /* now encode the old ticket if exists */
 429                 ret = ceph_x_encode_ticket(th, &p, end);
 430                 if (ret < 0)
 431                         return ret;
 432
 433                 return p - buf;
 434         }
 435
 436         if (need) {
 437                 void *p = head + 1;
 438                 struct ceph_x_service_ticket_request *req;
 439
 440                 if (p > end)
 441                         return -ERANGE;
 442                 head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
 443
 444                 BUG_ON(!th);
 445                 ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
 446                 if (ret)
 447                         return ret;
 448                 ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
 449                                  xi->auth_authorizer.buf->vec.iov_len);
 450
 451                 req = p;
 452                 req->keys = cpu_to_le32(need);
 453                 p += sizeof(*req);
 454                 return p - buf;
 455         }
 456
 457         return 0;
 458 }
 459
 460 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
 461                                void *buf, void *end)
 462 {
 463         struct ceph_x_info *xi = ac->private;
 464         struct ceph_x_reply_header *head = buf;
 465         struct ceph_x_ticket_handler *th;
 466         int len = end - buf;
 467         int op;
 468         int ret;
 469
 470         if (result)
 471                 return result;  /* XXX hmm? */
 472
 473         if (xi->starting) {
 474                 /* it's a hello */
 475                 struct ceph_x_server_challenge *sc = buf;
 476
 477                 if (len != sizeof(*sc))
 478                         return -EINVAL;
 479                 xi->server_challenge = le64_to_cpu(sc->server_challenge);
 480                 dout("handle_reply got server challenge %llx\n",
 481                      xi->server_challenge);
 482                 xi->starting = false;
 483                 xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
 484                 return -EAGAIN;
 485         }
 486
 487         op = le32_to_cpu(head->op);
 488         result = le32_to_cpu(head->result);
 489         dout("handle_reply op %d result %d\n", op, result);
 490         switch (op) {
 491         case CEPHX_GET_AUTH_SESSION_KEY:
 492                 /* verify auth key */
 493                 ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
 494                                                buf + sizeof(*head), end);
 495                 break;
 496
 497         case CEPHX_GET_PRINCIPAL_SESSION_KEY:
 498                 th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
 499                 BUG_ON(!th);
 500                 ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
 501                                                buf + sizeof(*head), end);
 502                 break;
 503
 504         default:
 505                 return -EINVAL;
 506         }
 507         if (ret)
 508                 return ret;
 509         if (ac->want_keys == xi->have_keys)
 510                 return 0;
 511         return -EAGAIN;
 512 }
 513
 514 static int ceph_x_create_authorizer(
 515         struct ceph_auth_client *ac, int peer_type,
 516         struct ceph_authorizer **a,
 517         void **buf, size_t *len,
 518         void **reply_buf, size_t *reply_len)
 519 {
 520         struct ceph_x_authorizer *au;
 521         struct ceph_x_ticket_handler *th;
 522         int ret;
 523
 524         th = get_ticket_handler(ac, peer_type);
 525         if (IS_ERR(th))
 526                 return PTR_ERR(th);
 527
 528         au = kzalloc(sizeof(*au), GFP_NOFS);
 529         if (!au)
 530                 return -ENOMEM;
 531
 532         ret = ceph_x_build_authorizer(ac, th, au);
 533         if (ret) {
 534                 kfree(au);
 535                 return ret;
 536         }
 537
 538         *a = (struct ceph_authorizer *)au;
 539         *buf = au->buf->vec.iov_base;
 540         *len = au->buf->vec.iov_len;
 541         *reply_buf = au->reply_buf;
 542         *reply_len = sizeof(au->reply_buf);
 543         return 0;
 544 }
 545
 546 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
 547                                           struct ceph_authorizer *a, size_t len)
 548 {
 549         struct ceph_x_authorizer *au = (void *)a;
 550         struct ceph_x_ticket_handler *th;
 551         int ret = 0;
 552         struct ceph_x_authorize_reply reply;
 553         void *p = au->reply_buf;
 554         void *end = p + sizeof(au->reply_buf);
 555
 556         th = get_ticket_handler(ac, au->service);
 557         if (!th)
 558                 return -EIO;  /* hrm! */
 559         ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
 560         if (ret < 0)
 561                 return ret;
 562         if (ret != sizeof(reply))
 563                 return -EPERM;
 564
 565         if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one))
 566                 ret = -EPERM;
 567         else
 568                 ret = 0;
 569         dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
 570              au->nonce, le64_to_cpu(reply.nonce_plus_one), ret);
 571         return ret;
 572 }
 573
 574 static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
 575                                       struct ceph_authorizer *a)
 576 {
 577         struct ceph_x_authorizer *au = (void *)a;
 578
 579         ceph_buffer_put(au->buf);
 580         kfree(au);
 581 }
 582
 583
 584 static void ceph_x_reset(struct ceph_auth_client *ac)
 585 {
 586         struct ceph_x_info *xi = ac->private;
 587
 588         dout("reset\n");
 589         xi->starting = true;
 590         xi->server_challenge = 0;
 591 }
 592
 593 static void ceph_x_destroy(struct ceph_auth_client *ac)
 594 {
 595         struct ceph_x_info *xi = ac->private;
 596         struct rb_node *p;
 597
 598         dout("ceph_x_destroy %p\n", ac);
 599         ceph_crypto_key_destroy(&xi->secret);
 600
 601         while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
 602                 struct ceph_x_ticket_handler *th =
 603                         rb_entry(p, struct ceph_x_ticket_handler, node);
 604                 remove_ticket_handler(ac, th);
 605         }
 606
 607         kmem_cache_destroy(ceph_x_ticketbuf_cachep);
 608
 609         kfree(ac->private);
 610         ac->private = NULL;
 611 }
 612
 613 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
 614                                    int peer_type)
 615 {
 616         struct ceph_x_ticket_handler *th;
 617
 618         th = get_ticket_handler(ac, peer_type);
 619         if (th && !IS_ERR(th))
 620                 remove_ticket_handler(ac, th);
 621 }
 622
 623
 624 static const struct ceph_auth_client_ops ceph_x_ops = {
 625         .is_authenticated = ceph_x_is_authenticated,
 626         .build_request = ceph_x_build_request,
 627         .handle_reply = ceph_x_handle_reply,
 628         .create_authorizer = ceph_x_create_authorizer,
 629         .verify_authorizer_reply = ceph_x_verify_authorizer_reply,
 630         .destroy_authorizer = ceph_x_destroy_authorizer,
 631         .invalidate_authorizer = ceph_x_invalidate_authorizer,
 632         .reset =  ceph_x_reset,
 633         .destroy = ceph_x_destroy,
 634 };
 635
 636
 637 int ceph_x_init(struct ceph_auth_client *ac)
 638 {
 639         struct ceph_x_info *xi;
 640         int ret;
 641
 642         dout("ceph_x_init %p\n", ac);
 643         xi = kzalloc(sizeof(*xi), GFP_NOFS);
 644         if (!xi)
 645                 return -ENOMEM;
 646
 647         ret = -ENOMEM;
 648         ceph_x_ticketbuf_cachep = kmem_cache_create("ceph_x_ticketbuf",
 649                                       TEMP_TICKET_BUF_LEN, 8,
 650                                       (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),
 651                                       NULL);
 652         if (!ceph_x_ticketbuf_cachep)
 653                 goto done_nomem;
 654         ret = -EINVAL;
 655         if (!ac->secret) {
 656                 pr_err("no secret set (for auth_x protocol)\n");
 657                 goto done_nomem;
 658         }
 659
 660         ret = ceph_crypto_key_unarmor(&xi->secret, ac->secret);
 661         if (ret)
 662                 goto done_nomem;
 663
 664         xi->starting = true;
 665         xi->ticket_handlers = RB_ROOT;
 666
 667         ac->protocol = CEPH_AUTH_CEPHX;
 668         ac->private = xi;
 669         ac->ops = &ceph_x_ops;
 670         return 0;
 671
 672 done_nomem:
 673         kfree(xi);
 674         if (ceph_x_ticketbuf_cachep)
 675                 kmem_cache_destroy(ceph_x_ticketbuf_cachep);
 676         return ret;
 677 }
 678
 679