Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspe...
[pandora-kernel.git] / 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 #include <linux/slab.h>
8
9 #include "auth_x.h"
10 #include "auth_x_protocol.h"
11 #include "crypto.h"
12 #include "auth.h"
13 #include "decode.h"
14
15 #define TEMP_TICKET_BUF_LEN     256
16
17 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
18
19 static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
20 {
21         struct ceph_x_info *xi = ac->private;
22         int need;
23
24         ceph_x_validate_tickets(ac, &need);
25         dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
26              ac->want_keys, need, xi->have_keys);
27         return (ac->want_keys & xi->have_keys) == ac->want_keys;
28 }
29
30 static int ceph_x_should_authenticate(struct ceph_auth_client *ac)
31 {
32         struct ceph_x_info *xi = ac->private;
33         int need;
34
35         ceph_x_validate_tickets(ac, &need);
36         dout("ceph_x_should_authenticate want=%d need=%d have=%d\n",
37              ac->want_keys, need, xi->have_keys);
38         return need != 0;
39 }
40
41 static int ceph_x_encrypt_buflen(int ilen)
42 {
43         return sizeof(struct ceph_x_encrypt_header) + ilen + 16 +
44                 sizeof(u32);
45 }
46
47 static int ceph_x_encrypt(struct ceph_crypto_key *secret,
48                           void *ibuf, int ilen, void *obuf, size_t olen)
49 {
50         struct ceph_x_encrypt_header head = {
51                 .struct_v = 1,
52                 .magic = cpu_to_le64(CEPHX_ENC_MAGIC)
53         };
54         size_t len = olen - sizeof(u32);
55         int ret;
56
57         ret = ceph_encrypt2(secret, obuf + sizeof(u32), &len,
58                             &head, sizeof(head), ibuf, ilen);
59         if (ret)
60                 return ret;
61         ceph_encode_32(&obuf, len);
62         return len + sizeof(u32);
63 }
64
65 static int ceph_x_decrypt(struct ceph_crypto_key *secret,
66                           void **p, void *end, void *obuf, size_t olen)
67 {
68         struct ceph_x_encrypt_header head;
69         size_t head_len = sizeof(head);
70         int len, ret;
71
72         len = ceph_decode_32(p);
73         if (*p + len > end)
74                 return -EINVAL;
75
76         dout("ceph_x_decrypt len %d\n", len);
77         ret = ceph_decrypt2(secret, &head, &head_len, obuf, &olen,
78                             *p, len);
79         if (ret)
80                 return ret;
81         if (head.struct_v != 1 || le64_to_cpu(head.magic) != CEPHX_ENC_MAGIC)
82                 return -EPERM;
83         *p += len;
84         return olen;
85 }
86
87 /*
88  * get existing (or insert new) ticket handler
89  */
90 static struct ceph_x_ticket_handler *
91 get_ticket_handler(struct ceph_auth_client *ac, int service)
92 {
93         struct ceph_x_ticket_handler *th;
94         struct ceph_x_info *xi = ac->private;
95         struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
96
97         while (*p) {
98                 parent = *p;
99                 th = rb_entry(parent, struct ceph_x_ticket_handler, node);
100                 if (service < th->service)
101                         p = &(*p)->rb_left;
102                 else if (service > th->service)
103                         p = &(*p)->rb_right;
104                 else
105                         return th;
106         }
107
108         /* add it */
109         th = kzalloc(sizeof(*th), GFP_NOFS);
110         if (!th)
111                 return ERR_PTR(-ENOMEM);
112         th->service = service;
113         rb_link_node(&th->node, parent, p);
114         rb_insert_color(&th->node, &xi->ticket_handlers);
115         return th;
116 }
117
118 static void remove_ticket_handler(struct ceph_auth_client *ac,
119                                   struct ceph_x_ticket_handler *th)
120 {
121         struct ceph_x_info *xi = ac->private;
122
123         dout("remove_ticket_handler %p %d\n", th, th->service);
124         rb_erase(&th->node, &xi->ticket_handlers);
125         ceph_crypto_key_destroy(&th->session_key);
126         if (th->ticket_blob)
127                 ceph_buffer_put(th->ticket_blob);
128         kfree(th);
129 }
130
131 static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
132                                     struct ceph_crypto_key *secret,
133                                     void *buf, void *end)
134 {
135         struct ceph_x_info *xi = ac->private;
136         int num;
137         void *p = buf;
138         int ret;
139         char *dbuf;
140         char *ticket_buf;
141         u8 reply_struct_v;
142
143         dbuf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
144         if (!dbuf)
145                 return -ENOMEM;
146
147         ret = -ENOMEM;
148         ticket_buf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
149         if (!ticket_buf)
150                 goto out_dbuf;
151
152         ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
153         reply_struct_v = ceph_decode_8(&p);
154         if (reply_struct_v != 1)
155                 goto bad;
156         num = ceph_decode_32(&p);
157         dout("%d tickets\n", num);
158         while (num--) {
159                 int type;
160                 u8 tkt_struct_v, blob_struct_v;
161                 struct ceph_x_ticket_handler *th;
162                 void *dp, *dend;
163                 int dlen;
164                 char is_enc;
165                 struct timespec validity;
166                 struct ceph_crypto_key old_key;
167                 void *tp, *tpend;
168                 struct ceph_timespec new_validity;
169                 struct ceph_crypto_key new_session_key;
170                 struct ceph_buffer *new_ticket_blob;
171                 unsigned long new_expires, new_renew_after;
172                 u64 new_secret_id;
173
174                 ceph_decode_need(&p, end, sizeof(u32) + 1, bad);
175
176                 type = ceph_decode_32(&p);
177                 dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
178
179                 tkt_struct_v = ceph_decode_8(&p);
180                 if (tkt_struct_v != 1)
181                         goto bad;
182
183                 th = get_ticket_handler(ac, type);
184                 if (IS_ERR(th)) {
185                         ret = PTR_ERR(th);
186                         goto out;
187                 }
188
189                 /* blob for me */
190                 dlen = ceph_x_decrypt(secret, &p, end, dbuf,
191                                       TEMP_TICKET_BUF_LEN);
192                 if (dlen <= 0) {
193                         ret = dlen;
194                         goto out;
195                 }
196                 dout(" decrypted %d bytes\n", dlen);
197                 dend = dbuf + dlen;
198                 dp = dbuf;
199
200                 tkt_struct_v = ceph_decode_8(&dp);
201                 if (tkt_struct_v != 1)
202                         goto bad;
203
204                 memcpy(&old_key, &th->session_key, sizeof(old_key));
205                 ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
206                 if (ret)
207                         goto out;
208
209                 ceph_decode_copy(&dp, &new_validity, sizeof(new_validity));
210                 ceph_decode_timespec(&validity, &new_validity);
211                 new_expires = get_seconds() + validity.tv_sec;
212                 new_renew_after = new_expires - (validity.tv_sec / 4);
213                 dout(" expires=%lu renew_after=%lu\n", new_expires,
214                      new_renew_after);
215
216                 /* ticket blob for service */
217                 ceph_decode_8_safe(&p, end, is_enc, bad);
218                 tp = ticket_buf;
219                 if (is_enc) {
220                         /* encrypted */
221                         dout(" encrypted ticket\n");
222                         dlen = ceph_x_decrypt(&old_key, &p, end, ticket_buf,
223                                               TEMP_TICKET_BUF_LEN);
224                         if (dlen < 0) {
225                                 ret = dlen;
226                                 goto out;
227                         }
228                         dlen = ceph_decode_32(&tp);
229                 } else {
230                         /* unencrypted */
231                         ceph_decode_32_safe(&p, end, dlen, bad);
232                         ceph_decode_need(&p, end, dlen, bad);
233                         ceph_decode_copy(&p, ticket_buf, dlen);
234                 }
235                 tpend = tp + dlen;
236                 dout(" ticket blob is %d bytes\n", dlen);
237                 ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
238                 blob_struct_v = ceph_decode_8(&tp);
239                 new_secret_id = ceph_decode_64(&tp);
240                 ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
241                 if (ret)
242                         goto out;
243
244                 /* all is well, update our ticket */
245                 ceph_crypto_key_destroy(&th->session_key);
246                 if (th->ticket_blob)
247                         ceph_buffer_put(th->ticket_blob);
248                 th->session_key = new_session_key;
249                 th->ticket_blob = new_ticket_blob;
250                 th->validity = new_validity;
251                 th->secret_id = new_secret_id;
252                 th->expires = new_expires;
253                 th->renew_after = new_renew_after;
254                 dout(" got ticket service %d (%s) secret_id %lld len %d\n",
255                      type, ceph_entity_type_name(type), th->secret_id,
256                      (int)th->ticket_blob->vec.iov_len);
257                 xi->have_keys |= th->service;
258         }
259
260         ret = 0;
261 out:
262         kfree(ticket_buf);
263 out_dbuf:
264         kfree(dbuf);
265         return ret;
266
267 bad:
268         ret = -EINVAL;
269         goto out;
270 }
271
272 static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
273                                    struct ceph_x_ticket_handler *th,
274                                    struct ceph_x_authorizer *au)
275 {
276         int maxlen;
277         struct ceph_x_authorize_a *msg_a;
278         struct ceph_x_authorize_b msg_b;
279         void *p, *end;
280         int ret;
281         int ticket_blob_len =
282                 (th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
283
284         dout("build_authorizer for %s %p\n",
285              ceph_entity_type_name(th->service), au);
286
287         maxlen = sizeof(*msg_a) + sizeof(msg_b) +
288                 ceph_x_encrypt_buflen(ticket_blob_len);
289         dout("  need len %d\n", maxlen);
290         if (au->buf && au->buf->alloc_len < maxlen) {
291                 ceph_buffer_put(au->buf);
292                 au->buf = NULL;
293         }
294         if (!au->buf) {
295                 au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
296                 if (!au->buf)
297                         return -ENOMEM;
298         }
299         au->service = th->service;
300
301         msg_a = au->buf->vec.iov_base;
302         msg_a->struct_v = 1;
303         msg_a->global_id = cpu_to_le64(ac->global_id);
304         msg_a->service_id = cpu_to_le32(th->service);
305         msg_a->ticket_blob.struct_v = 1;
306         msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
307         msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
308         if (ticket_blob_len) {
309                 memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
310                        th->ticket_blob->vec.iov_len);
311         }
312         dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
313              le64_to_cpu(msg_a->ticket_blob.secret_id));
314
315         p = msg_a + 1;
316         p += ticket_blob_len;
317         end = au->buf->vec.iov_base + au->buf->vec.iov_len;
318
319         get_random_bytes(&au->nonce, sizeof(au->nonce));
320         msg_b.struct_v = 1;
321         msg_b.nonce = cpu_to_le64(au->nonce);
322         ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b),
323                              p, end - p);
324         if (ret < 0)
325                 goto out_buf;
326         p += ret;
327         au->buf->vec.iov_len = p - au->buf->vec.iov_base;
328         dout(" built authorizer nonce %llx len %d\n", au->nonce,
329              (int)au->buf->vec.iov_len);
330         BUG_ON(au->buf->vec.iov_len > maxlen);
331         return 0;
332
333 out_buf:
334         ceph_buffer_put(au->buf);
335         au->buf = NULL;
336         return ret;
337 }
338
339 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
340                                 void **p, void *end)
341 {
342         ceph_decode_need(p, end, 1 + sizeof(u64), bad);
343         ceph_encode_8(p, 1);
344         ceph_encode_64(p, th->secret_id);
345         if (th->ticket_blob) {
346                 const char *buf = th->ticket_blob->vec.iov_base;
347                 u32 len = th->ticket_blob->vec.iov_len;
348
349                 ceph_encode_32_safe(p, end, len, bad);
350                 ceph_encode_copy_safe(p, end, buf, len, bad);
351         } else {
352                 ceph_encode_32_safe(p, end, 0, bad);
353         }
354
355         return 0;
356 bad:
357         return -ERANGE;
358 }
359
360 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
361 {
362         int want = ac->want_keys;
363         struct ceph_x_info *xi = ac->private;
364         int service;
365
366         *pneed = ac->want_keys & ~(xi->have_keys);
367
368         for (service = 1; service <= want; service <<= 1) {
369                 struct ceph_x_ticket_handler *th;
370
371                 if (!(ac->want_keys & service))
372                         continue;
373
374                 if (*pneed & service)
375                         continue;
376
377                 th = get_ticket_handler(ac, service);
378
379                 if (!th) {
380                         *pneed |= service;
381                         continue;
382                 }
383
384                 if (get_seconds() >= th->renew_after)
385                         *pneed |= service;
386                 if (get_seconds() >= th->expires)
387                         xi->have_keys &= ~service;
388         }
389 }
390
391
392 static int ceph_x_build_request(struct ceph_auth_client *ac,
393                                 void *buf, void *end)
394 {
395         struct ceph_x_info *xi = ac->private;
396         int need;
397         struct ceph_x_request_header *head = buf;
398         int ret;
399         struct ceph_x_ticket_handler *th =
400                 get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
401
402         ceph_x_validate_tickets(ac, &need);
403
404         dout("build_request want %x have %x need %x\n",
405              ac->want_keys, xi->have_keys, need);
406
407         if (need & CEPH_ENTITY_TYPE_AUTH) {
408                 struct ceph_x_authenticate *auth = (void *)(head + 1);
409                 void *p = auth + 1;
410                 struct ceph_x_challenge_blob tmp;
411                 char tmp_enc[40];
412                 u64 *u;
413
414                 if (p > end)
415                         return -ERANGE;
416
417                 dout(" get_auth_session_key\n");
418                 head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
419
420                 /* encrypt and hash */
421                 get_random_bytes(&auth->client_challenge, sizeof(u64));
422                 tmp.client_challenge = auth->client_challenge;
423                 tmp.server_challenge = cpu_to_le64(xi->server_challenge);
424                 ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp),
425                                      tmp_enc, sizeof(tmp_enc));
426                 if (ret < 0)
427                         return ret;
428
429                 auth->struct_v = 1;
430                 auth->key = 0;
431                 for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++)
432                         auth->key ^= *(__le64 *)u;
433                 dout(" server_challenge %llx client_challenge %llx key %llx\n",
434                      xi->server_challenge, le64_to_cpu(auth->client_challenge),
435                      le64_to_cpu(auth->key));
436
437                 /* now encode the old ticket if exists */
438                 ret = ceph_x_encode_ticket(th, &p, end);
439                 if (ret < 0)
440                         return ret;
441
442                 return p - buf;
443         }
444
445         if (need) {
446                 void *p = head + 1;
447                 struct ceph_x_service_ticket_request *req;
448
449                 if (p > end)
450                         return -ERANGE;
451                 head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
452
453                 BUG_ON(!th);
454                 ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
455                 if (ret)
456                         return ret;
457                 ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
458                                  xi->auth_authorizer.buf->vec.iov_len);
459
460                 req = p;
461                 req->keys = cpu_to_le32(need);
462                 p += sizeof(*req);
463                 return p - buf;
464         }
465
466         return 0;
467 }
468
469 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
470                                void *buf, void *end)
471 {
472         struct ceph_x_info *xi = ac->private;
473         struct ceph_x_reply_header *head = buf;
474         struct ceph_x_ticket_handler *th;
475         int len = end - buf;
476         int op;
477         int ret;
478
479         if (result)
480                 return result;  /* XXX hmm? */
481
482         if (xi->starting) {
483                 /* it's a hello */
484                 struct ceph_x_server_challenge *sc = buf;
485
486                 if (len != sizeof(*sc))
487                         return -EINVAL;
488                 xi->server_challenge = le64_to_cpu(sc->server_challenge);
489                 dout("handle_reply got server challenge %llx\n",
490                      xi->server_challenge);
491                 xi->starting = false;
492                 xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
493                 return -EAGAIN;
494         }
495
496         op = le16_to_cpu(head->op);
497         result = le32_to_cpu(head->result);
498         dout("handle_reply op %d result %d\n", op, result);
499         switch (op) {
500         case CEPHX_GET_AUTH_SESSION_KEY:
501                 /* verify auth key */
502                 ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
503                                                buf + sizeof(*head), end);
504                 break;
505
506         case CEPHX_GET_PRINCIPAL_SESSION_KEY:
507                 th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
508                 BUG_ON(!th);
509                 ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
510                                                buf + sizeof(*head), end);
511                 break;
512
513         default:
514                 return -EINVAL;
515         }
516         if (ret)
517                 return ret;
518         if (ac->want_keys == xi->have_keys)
519                 return 0;
520         return -EAGAIN;
521 }
522
523 static int ceph_x_create_authorizer(
524         struct ceph_auth_client *ac, int peer_type,
525         struct ceph_authorizer **a,
526         void **buf, size_t *len,
527         void **reply_buf, size_t *reply_len)
528 {
529         struct ceph_x_authorizer *au;
530         struct ceph_x_ticket_handler *th;
531         int ret;
532
533         th = get_ticket_handler(ac, peer_type);
534         if (IS_ERR(th))
535                 return PTR_ERR(th);
536
537         au = kzalloc(sizeof(*au), GFP_NOFS);
538         if (!au)
539                 return -ENOMEM;
540
541         ret = ceph_x_build_authorizer(ac, th, au);
542         if (ret) {
543                 kfree(au);
544                 return ret;
545         }
546
547         *a = (struct ceph_authorizer *)au;
548         *buf = au->buf->vec.iov_base;
549         *len = au->buf->vec.iov_len;
550         *reply_buf = au->reply_buf;
551         *reply_len = sizeof(au->reply_buf);
552         return 0;
553 }
554
555 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
556                                           struct ceph_authorizer *a, size_t len)
557 {
558         struct ceph_x_authorizer *au = (void *)a;
559         struct ceph_x_ticket_handler *th;
560         int ret = 0;
561         struct ceph_x_authorize_reply reply;
562         void *p = au->reply_buf;
563         void *end = p + sizeof(au->reply_buf);
564
565         th = get_ticket_handler(ac, au->service);
566         if (!th)
567                 return -EIO;  /* hrm! */
568         ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
569         if (ret < 0)
570                 return ret;
571         if (ret != sizeof(reply))
572                 return -EPERM;
573
574         if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one))
575                 ret = -EPERM;
576         else
577                 ret = 0;
578         dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
579              au->nonce, le64_to_cpu(reply.nonce_plus_one), ret);
580         return ret;
581 }
582
583 static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
584                                       struct ceph_authorizer *a)
585 {
586         struct ceph_x_authorizer *au = (void *)a;
587
588         ceph_buffer_put(au->buf);
589         kfree(au);
590 }
591
592
593 static void ceph_x_reset(struct ceph_auth_client *ac)
594 {
595         struct ceph_x_info *xi = ac->private;
596
597         dout("reset\n");
598         xi->starting = true;
599         xi->server_challenge = 0;
600 }
601
602 static void ceph_x_destroy(struct ceph_auth_client *ac)
603 {
604         struct ceph_x_info *xi = ac->private;
605         struct rb_node *p;
606
607         dout("ceph_x_destroy %p\n", ac);
608         ceph_crypto_key_destroy(&xi->secret);
609
610         while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
611                 struct ceph_x_ticket_handler *th =
612                         rb_entry(p, struct ceph_x_ticket_handler, node);
613                 remove_ticket_handler(ac, th);
614         }
615
616         if (xi->auth_authorizer.buf)
617                 ceph_buffer_put(xi->auth_authorizer.buf);
618
619         kfree(ac->private);
620         ac->private = NULL;
621 }
622
623 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
624                                    int peer_type)
625 {
626         struct ceph_x_ticket_handler *th;
627
628         th = get_ticket_handler(ac, peer_type);
629         if (th && !IS_ERR(th))
630                 remove_ticket_handler(ac, th);
631 }
632
633
634 static const struct ceph_auth_client_ops ceph_x_ops = {
635         .name = "x",
636         .is_authenticated = ceph_x_is_authenticated,
637         .should_authenticate = ceph_x_should_authenticate,
638         .build_request = ceph_x_build_request,
639         .handle_reply = ceph_x_handle_reply,
640         .create_authorizer = ceph_x_create_authorizer,
641         .verify_authorizer_reply = ceph_x_verify_authorizer_reply,
642         .destroy_authorizer = ceph_x_destroy_authorizer,
643         .invalidate_authorizer = ceph_x_invalidate_authorizer,
644         .reset =  ceph_x_reset,
645         .destroy = ceph_x_destroy,
646 };
647
648
649 int ceph_x_init(struct ceph_auth_client *ac)
650 {
651         struct ceph_x_info *xi;
652         int ret;
653
654         dout("ceph_x_init %p\n", ac);
655         ret = -ENOMEM;
656         xi = kzalloc(sizeof(*xi), GFP_NOFS);
657         if (!xi)
658                 goto out;
659
660         ret = -EINVAL;
661         if (!ac->secret) {
662                 pr_err("no secret set (for auth_x protocol)\n");
663                 goto out_nomem;
664         }
665
666         ret = ceph_crypto_key_unarmor(&xi->secret, ac->secret);
667         if (ret)
668                 goto out_nomem;
669
670         xi->starting = true;
671         xi->ticket_handlers = RB_ROOT;
672
673         ac->protocol = CEPH_AUTH_CEPHX;
674         ac->private = xi;
675         ac->ops = &ceph_x_ops;
676         return 0;
677
678 out_nomem:
679         kfree(xi);
680 out:
681         return ret;
682 }
683
684