SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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_buffer *new_ticket_blob;
 160
 161                 ceph_decode_need(&p, end, sizeof(u32) + 1, bad);
 162
 163                 type = ceph_decode_32(&p);
 164                 dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
 165
 166                 struct_v = ceph_decode_8(&p);
 167                 if (struct_v != 1)
 168                         goto bad;
 169
 170                 th = get_ticket_handler(ac, type);
 171                 if (IS_ERR(th)) {
 172                         ret = PTR_ERR(th);
 173                         goto out;
 174                 }
 175
 176                 /* blob for me */
 177                 dlen = ceph_x_decrypt(secret, &p, end, dbuf,
 178                                       TEMP_TICKET_BUF_LEN);
 179                 if (dlen <= 0) {
 180                         ret = dlen;
 181                         goto out;
 182                 }
 183                 dout(" decrypted %d bytes\n", dlen);
 184                 dend = dbuf + dlen;
 185                 dp = dbuf;
 186
 187                 struct_v = ceph_decode_8(&dp);
 188                 if (struct_v != 1)
 189                         goto bad;
 190
 191                 memcpy(&old_key, &th->session_key, sizeof(old_key));
 192                 ret = ceph_crypto_key_decode(&th->session_key, &dp, dend);
 193                 if (ret)
 194                         goto out;
 195
 196                 ceph_decode_copy(&dp, &th->validity, sizeof(th->validity));
 197                 ceph_decode_timespec(&validity, &th->validity);
 198                 th->expires = get_seconds() + validity.tv_sec;
 199                 th->renew_after = th->expires - (validity.tv_sec / 4);
 200                 dout(" expires=%lu renew_after=%lu\n", th->expires,
 201                      th->renew_after);
 202
 203                 /* ticket blob for service */
 204                 ceph_decode_8_safe(&p, end, is_enc, bad);
 205                 tp = ticket_buf;
 206                 if (is_enc) {
 207                         /* encrypted */
 208                         dout(" encrypted ticket\n");
 209                         dlen = ceph_x_decrypt(&old_key, &p, end, ticket_buf,
 210                                               TEMP_TICKET_BUF_LEN);
 211                         if (dlen < 0) {
 212                                 ret = dlen;
 213                                 goto out;
 214                         }
 215                         dlen = ceph_decode_32(&tp);
 216                 } else {
 217                         /* unencrypted */
 218                         ceph_decode_32_safe(&p, end, dlen, bad);
 219                         ceph_decode_need(&p, end, dlen, bad);
 220                         ceph_decode_copy(&p, ticket_buf, dlen);
 221                 }
 222                 tpend = tp + dlen;
 223                 dout(" ticket blob is %d bytes\n", dlen);
 224                 ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
 225                 struct_v = ceph_decode_8(&tp);
 226                 th->secret_id = ceph_decode_64(&tp);
 227                 ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
 228                 if (ret)
 229                         goto out;
 230                 if (th->ticket_blob)
 231                         ceph_buffer_put(th->ticket_blob);
 232                 th->ticket_blob = new_ticket_blob;
 233                 dout(" got ticket service %d (%s) secret_id %lld len %d\n",
 234                      type, ceph_entity_type_name(type), th->secret_id,
 235                      (int)th->ticket_blob->vec.iov_len);
 236                 xi->have_keys |= th->service;
 237         }
 238
 239         ret = 0;
 240 out:
 241         kmem_cache_free(ceph_x_ticketbuf_cachep, ticket_buf);
 242 out_dbuf:
 243         kmem_cache_free(ceph_x_ticketbuf_cachep, dbuf);
 244         return ret;
 245
 246 bad:
 247         ret = -EINVAL;
 248         goto out;
 249 }
 250
 251 static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
 252                                    struct ceph_x_ticket_handler *th,
 253                                    struct ceph_x_authorizer *au)
 254 {
 255         int maxlen;
 256         struct ceph_x_authorize_a *msg_a;
 257         struct ceph_x_authorize_b msg_b;
 258         void *p, *end;
 259         int ret;
 260         int ticket_blob_len =
 261                 (th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
 262
 263         dout("build_authorizer for %s %p\n",
 264              ceph_entity_type_name(th->service), au);
 265
 266         maxlen = sizeof(*msg_a) + sizeof(msg_b) +
 267                 ceph_x_encrypt_buflen(ticket_blob_len);
 268         dout("  need len %d\n", maxlen);
 269         if (au->buf && au->buf->alloc_len < maxlen) {
 270                 ceph_buffer_put(au->buf);
 271                 au->buf = NULL;
 272         }
 273         if (!au->buf) {
 274                 au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
 275                 if (!au->buf)
 276                         return -ENOMEM;
 277         }
 278         au->service = th->service;
 279
 280         msg_a = au->buf->vec.iov_base;
 281         msg_a->struct_v = 1;
 282         msg_a->global_id = cpu_to_le64(ac->global_id);
 283         msg_a->service_id = cpu_to_le32(th->service);
 284         msg_a->ticket_blob.struct_v = 1;
 285         msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
 286         msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
 287         if (ticket_blob_len) {
 288                 memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
 289                        th->ticket_blob->vec.iov_len);
 290         }
 291         dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
 292              le64_to_cpu(msg_a->ticket_blob.secret_id));
 293
 294         p = msg_a + 1;
 295         p += ticket_blob_len;
 296         end = au->buf->vec.iov_base + au->buf->vec.iov_len;
 297
 298         get_random_bytes(&au->nonce, sizeof(au->nonce));
 299         msg_b.struct_v = 1;
 300         msg_b.nonce = cpu_to_le64(au->nonce);
 301         ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b),
 302                              p, end - p);
 303         if (ret < 0)
 304                 goto out_buf;
 305         p += ret;
 306         au->buf->vec.iov_len = p - au->buf->vec.iov_base;
 307         dout(" built authorizer nonce %llx len %d\n", au->nonce,
 308              (int)au->buf->vec.iov_len);
 309         BUG_ON(au->buf->vec.iov_len > maxlen);
 310         return 0;
 311
 312 out_buf:
 313         ceph_buffer_put(au->buf);
 314         au->buf = NULL;
 315         return ret;
 316 }
 317
 318 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
 319                                 void **p, void *end)
 320 {
 321         ceph_decode_need(p, end, 1 + sizeof(u64), bad);
 322         ceph_encode_8(p, 1);
 323         ceph_encode_64(p, th->secret_id);
 324         if (th->ticket_blob) {
 325                 const char *buf = th->ticket_blob->vec.iov_base;
 326                 u32 len = th->ticket_blob->vec.iov_len;
 327
 328                 ceph_encode_32_safe(p, end, len, bad);
 329                 ceph_encode_copy_safe(p, end, buf, len, bad);
 330         } else {
 331                 ceph_encode_32_safe(p, end, 0, bad);
 332         }
 333
 334         return 0;
 335 bad:
 336         return -ERANGE;
 337 }
 338
 339 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
 340 {
 341         int want = ac->want_keys;
 342         struct ceph_x_info *xi = ac->private;
 343         int service;
 344
 345         *pneed = ac->want_keys & ~(xi->have_keys);
 346
 347         for (service = 1; service <= want; service <<= 1) {
 348                 struct ceph_x_ticket_handler *th;
 349
 350                 if (!(ac->want_keys & service))
 351                         continue;
 352
 353                 if (*pneed & service)
 354                         continue;
 355
 356                 th = get_ticket_handler(ac, service);
 357
 358                 if (!th) {
 359                         *pneed |= service;
 360                         continue;
 361                 }
 362
 363                 if (get_seconds() >= th->renew_after)
 364                         *pneed |= service;
 365                 if (get_seconds() >= th->expires)
 366                         xi->have_keys &= ~service;
 367         }
 368 }
 369
 370
 371 static int ceph_x_build_request(struct ceph_auth_client *ac,
 372                                 void *buf, void *end)
 373 {
 374         struct ceph_x_info *xi = ac->private;
 375         int need;
 376         struct ceph_x_request_header *head = buf;
 377         int ret;
 378         struct ceph_x_ticket_handler *th =
 379                 get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
 380
 381         ceph_x_validate_tickets(ac, &need);
 382
 383         dout("build_request want %x have %x need %x\n",
 384              ac->want_keys, xi->have_keys, need);
 385
 386         if (need & CEPH_ENTITY_TYPE_AUTH) {
 387                 struct ceph_x_authenticate *auth = (void *)(head + 1);
 388                 void *p = auth + 1;
 389                 struct ceph_x_challenge_blob tmp;
 390                 char tmp_enc[40];
 391                 u64 *u;
 392
 393                 if (p > end)
 394                         return -ERANGE;
 395
 396                 dout(" get_auth_session_key\n");
 397                 head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
 398
 399                 /* encrypt and hash */
 400                 get_random_bytes(&auth->client_challenge, sizeof(u64));
 401                 tmp.client_challenge = auth->client_challenge;
 402                 tmp.server_challenge = cpu_to_le64(xi->server_challenge);
 403                 ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp),
 404                                      tmp_enc, sizeof(tmp_enc));
 405                 if (ret < 0)
 406                         return ret;
 407
 408                 auth->struct_v = 1;
 409                 auth->key = 0;
 410                 for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++)
 411                         auth->key ^= *u;
 412                 dout(" server_challenge %llx client_challenge %llx key %llx\n",
 413                      xi->server_challenge, le64_to_cpu(auth->client_challenge),
 414                      le64_to_cpu(auth->key));
 415
 416                 /* now encode the old ticket if exists */
 417                 ret = ceph_x_encode_ticket(th, &p, end);
 418                 if (ret < 0)
 419                         return ret;
 420
 421                 return p - buf;
 422         }
 423
 424         if (need) {
 425                 void *p = head + 1;
 426                 struct ceph_x_service_ticket_request *req;
 427
 428                 if (p > end)
 429                         return -ERANGE;
 430                 head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
 431
 432                 BUG_ON(!th);
 433                 ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
 434                 if (ret)
 435                         return ret;
 436                 ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
 437                                  xi->auth_authorizer.buf->vec.iov_len);
 438
 439                 req = p;
 440                 req->keys = cpu_to_le32(need);
 441                 p += sizeof(*req);
 442                 return p - buf;
 443         }
 444
 445         return 0;
 446 }
 447
 448 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
 449                                void *buf, void *end)
 450 {
 451         struct ceph_x_info *xi = ac->private;
 452         struct ceph_x_reply_header *head = buf;
 453         struct ceph_x_ticket_handler *th;
 454         int len = end - buf;
 455         int op;
 456         int ret;
 457
 458         if (result)
 459                 return result;  /* XXX hmm? */
 460
 461         if (xi->starting) {
 462                 /* it's a hello */
 463                 struct ceph_x_server_challenge *sc = buf;
 464
 465                 if (len != sizeof(*sc))
 466                         return -EINVAL;
 467                 xi->server_challenge = le64_to_cpu(sc->server_challenge);
 468                 dout("handle_reply got server challenge %llx\n",
 469                      xi->server_challenge);
 470                 xi->starting = false;
 471                 xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
 472                 return -EAGAIN;
 473         }
 474
 475         op = le32_to_cpu(head->op);
 476         result = le32_to_cpu(head->result);
 477         dout("handle_reply op %d result %d\n", op, result);
 478         switch (op) {
 479         case CEPHX_GET_AUTH_SESSION_KEY:
 480                 /* verify auth key */
 481                 ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
 482                                                buf + sizeof(*head), end);
 483                 break;
 484
 485         case CEPHX_GET_PRINCIPAL_SESSION_KEY:
 486                 th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
 487                 BUG_ON(!th);
 488                 ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
 489                                                buf + sizeof(*head), end);
 490                 break;
 491
 492         default:
 493                 return -EINVAL;
 494         }
 495         if (ret)
 496                 return ret;
 497         if (ac->want_keys == xi->have_keys)
 498                 return 0;
 499         return -EAGAIN;
 500 }
 501
 502 static int ceph_x_create_authorizer(
 503         struct ceph_auth_client *ac, int peer_type,
 504         struct ceph_authorizer **a,
 505         void **buf, size_t *len,
 506         void **reply_buf, size_t *reply_len)
 507 {
 508         struct ceph_x_authorizer *au;
 509         struct ceph_x_ticket_handler *th;
 510         int ret;
 511
 512         th = get_ticket_handler(ac, peer_type);
 513         if (IS_ERR(th))
 514                 return PTR_ERR(th);
 515
 516         au = kzalloc(sizeof(*au), GFP_NOFS);
 517         if (!au)
 518                 return -ENOMEM;
 519
 520         ret = ceph_x_build_authorizer(ac, th, au);
 521         if (ret) {
 522                 kfree(au);
 523                 return ret;
 524         }
 525
 526         *a = (struct ceph_authorizer *)au;
 527         *buf = au->buf->vec.iov_base;
 528         *len = au->buf->vec.iov_len;
 529         *reply_buf = au->reply_buf;
 530         *reply_len = sizeof(au->reply_buf);
 531         return 0;
 532 }
 533
 534 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
 535                                           struct ceph_authorizer *a, size_t len)
 536 {
 537         struct ceph_x_authorizer *au = (void *)a;
 538         struct ceph_x_ticket_handler *th;
 539         int ret = 0;
 540         struct ceph_x_authorize_reply reply;
 541         void *p = au->reply_buf;
 542         void *end = p + sizeof(au->reply_buf);
 543
 544         th = get_ticket_handler(ac, au->service);
 545         if (!th)
 546                 return -EIO;  /* hrm! */
 547         ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
 548         if (ret < 0)
 549                 return ret;
 550         if (ret != sizeof(reply))
 551                 return -EPERM;
 552
 553         if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one))
 554                 ret = -EPERM;
 555         else
 556                 ret = 0;
 557         dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
 558              au->nonce, le64_to_cpu(reply.nonce_plus_one), ret);
 559         return ret;
 560 }
 561
 562 static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
 563                                       struct ceph_authorizer *a)
 564 {
 565         struct ceph_x_authorizer *au = (void *)a;
 566
 567         ceph_buffer_put(au->buf);
 568         kfree(au);
 569 }
 570
 571
 572 static void ceph_x_reset(struct ceph_auth_client *ac)
 573 {
 574         struct ceph_x_info *xi = ac->private;
 575
 576         dout("reset\n");
 577         xi->starting = true;
 578         xi->server_challenge = 0;
 579 }
 580
 581 static void ceph_x_destroy(struct ceph_auth_client *ac)
 582 {
 583         struct ceph_x_info *xi = ac->private;
 584         struct rb_node *p;
 585
 586         dout("ceph_x_destroy %p\n", ac);
 587         ceph_crypto_key_destroy(&xi->secret);
 588
 589         while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
 590                 struct ceph_x_ticket_handler *th =
 591                         rb_entry(p, struct ceph_x_ticket_handler, node);
 592                 remove_ticket_handler(ac, th);
 593         }
 594
 595         kmem_cache_destroy(ceph_x_ticketbuf_cachep);
 596
 597         kfree(ac->private);
 598         ac->private = NULL;
 599 }
 600
 601 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
 602                                    int peer_type)
 603 {
 604         struct ceph_x_ticket_handler *th;
 605
 606         th = get_ticket_handler(ac, peer_type);
 607         if (th && !IS_ERR(th))
 608                 remove_ticket_handler(ac, th);
 609 }
 610
 611
 612 static const struct ceph_auth_client_ops ceph_x_ops = {
 613         .is_authenticated = ceph_x_is_authenticated,
 614         .build_request = ceph_x_build_request,
 615         .handle_reply = ceph_x_handle_reply,
 616         .create_authorizer = ceph_x_create_authorizer,
 617         .verify_authorizer_reply = ceph_x_verify_authorizer_reply,
 618         .destroy_authorizer = ceph_x_destroy_authorizer,
 619         .invalidate_authorizer = ceph_x_invalidate_authorizer,
 620         .reset =  ceph_x_reset,
 621         .destroy = ceph_x_destroy,
 622 };
 623
 624
 625 int ceph_x_init(struct ceph_auth_client *ac)
 626 {
 627         struct ceph_x_info *xi;
 628         int ret;
 629
 630         dout("ceph_x_init %p\n", ac);
 631         xi = kzalloc(sizeof(*xi), GFP_NOFS);
 632         if (!xi)
 633                 return -ENOMEM;
 634
 635         ret = -ENOMEM;
 636         ceph_x_ticketbuf_cachep = kmem_cache_create("ceph_x_ticketbuf",
 637                                       TEMP_TICKET_BUF_LEN, 8,
 638                                       (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),
 639                                       NULL);
 640         if (!ceph_x_ticketbuf_cachep)
 641                 goto done_nomem;
 642         ret = -EINVAL;
 643         if (!ac->secret) {
 644                 pr_err("no secret set (for auth_x protocol)\n");
 645                 goto done_nomem;
 646         }
 647
 648         ret = ceph_crypto_key_unarmor(&xi->secret, ac->secret);
 649         if (ret)
 650                 goto done_nomem;
 651
 652         xi->starting = true;
 653         xi->ticket_handlers = RB_ROOT;
 654
 655         ac->protocol = CEPH_AUTH_CEPHX;
 656         ac->private = xi;
 657         ac->ops = &ceph_x_ops;
 658         return 0;
 659
 660 done_nomem:
 661         kfree(xi);
 662         if (ceph_x_ticketbuf_cachep)
 663                 kmem_cache_destroy(ceph_x_ticketbuf_cachep);
 664         return ret;
 665 }
 666
 667