xref: /linux/net/ceph/auth_x.c (revision e21f9e2e862e9eb3dd64eaddb6256b3e5098660f)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/ceph/ceph_debug.h>
4 
5 #include <linux/err.h>
6 #include <linux/module.h>
7 #include <linux/random.h>
8 #include <linux/slab.h>
9 
10 #include <linux/ceph/decode.h>
11 #include <linux/ceph/auth.h>
12 #include <linux/ceph/libceph.h>
13 #include <linux/ceph/messenger.h>
14 
15 #include "crypto.h"
16 #include "auth_x.h"
17 #include "auth_x_protocol.h"
18 
19 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
20 
21 static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
22 {
23 	struct ceph_x_info *xi = ac->private;
24 	int need;
25 
26 	ceph_x_validate_tickets(ac, &need);
27 	dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
28 	     ac->want_keys, need, xi->have_keys);
29 	return (ac->want_keys & xi->have_keys) == ac->want_keys;
30 }
31 
32 static int ceph_x_should_authenticate(struct ceph_auth_client *ac)
33 {
34 	struct ceph_x_info *xi = ac->private;
35 	int need;
36 
37 	ceph_x_validate_tickets(ac, &need);
38 	dout("ceph_x_should_authenticate want=%d need=%d have=%d\n",
39 	     ac->want_keys, need, xi->have_keys);
40 	return need != 0;
41 }
42 
43 static int ceph_x_encrypt_offset(void)
44 {
45 	return sizeof(u32) + sizeof(struct ceph_x_encrypt_header);
46 }
47 
48 static int ceph_x_encrypt_buflen(int ilen)
49 {
50 	return ceph_x_encrypt_offset() + ilen + 16;
51 }
52 
53 static int ceph_x_encrypt(struct ceph_crypto_key *secret, void *buf,
54 			  int buf_len, int plaintext_len)
55 {
56 	struct ceph_x_encrypt_header *hdr = buf + sizeof(u32);
57 	int ciphertext_len;
58 	int ret;
59 
60 	hdr->struct_v = 1;
61 	hdr->magic = cpu_to_le64(CEPHX_ENC_MAGIC);
62 
63 	ret = ceph_crypt(secret, true, buf + sizeof(u32), buf_len - sizeof(u32),
64 			 plaintext_len + sizeof(struct ceph_x_encrypt_header),
65 			 &ciphertext_len);
66 	if (ret)
67 		return ret;
68 
69 	ceph_encode_32(&buf, ciphertext_len);
70 	return sizeof(u32) + ciphertext_len;
71 }
72 
73 static int ceph_x_decrypt(struct ceph_crypto_key *secret, void **p, void *end)
74 {
75 	struct ceph_x_encrypt_header *hdr = *p + sizeof(u32);
76 	int ciphertext_len, plaintext_len;
77 	int ret;
78 
79 	ceph_decode_32_safe(p, end, ciphertext_len, e_inval);
80 	ceph_decode_need(p, end, ciphertext_len, e_inval);
81 
82 	ret = ceph_crypt(secret, false, *p, end - *p, ciphertext_len,
83 			 &plaintext_len);
84 	if (ret)
85 		return ret;
86 
87 	if (hdr->struct_v != 1 || le64_to_cpu(hdr->magic) != CEPHX_ENC_MAGIC)
88 		return -EPERM;
89 
90 	*p += ciphertext_len;
91 	return plaintext_len - sizeof(struct ceph_x_encrypt_header);
92 
93 e_inval:
94 	return -EINVAL;
95 }
96 
97 /*
98  * get existing (or insert new) ticket handler
99  */
100 static struct ceph_x_ticket_handler *
101 get_ticket_handler(struct ceph_auth_client *ac, int service)
102 {
103 	struct ceph_x_ticket_handler *th;
104 	struct ceph_x_info *xi = ac->private;
105 	struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
106 
107 	while (*p) {
108 		parent = *p;
109 		th = rb_entry(parent, struct ceph_x_ticket_handler, node);
110 		if (service < th->service)
111 			p = &(*p)->rb_left;
112 		else if (service > th->service)
113 			p = &(*p)->rb_right;
114 		else
115 			return th;
116 	}
117 
118 	/* add it */
119 	th = kzalloc(sizeof(*th), GFP_NOFS);
120 	if (!th)
121 		return ERR_PTR(-ENOMEM);
122 	th->service = service;
123 	rb_link_node(&th->node, parent, p);
124 	rb_insert_color(&th->node, &xi->ticket_handlers);
125 	return th;
126 }
127 
128 static void remove_ticket_handler(struct ceph_auth_client *ac,
129 				  struct ceph_x_ticket_handler *th)
130 {
131 	struct ceph_x_info *xi = ac->private;
132 
133 	dout("remove_ticket_handler %p %d\n", th, th->service);
134 	rb_erase(&th->node, &xi->ticket_handlers);
135 	ceph_crypto_key_destroy(&th->session_key);
136 	if (th->ticket_blob)
137 		ceph_buffer_put(th->ticket_blob);
138 	kfree(th);
139 }
140 
141 static int process_one_ticket(struct ceph_auth_client *ac,
142 			      struct ceph_crypto_key *secret,
143 			      void **p, void *end)
144 {
145 	struct ceph_x_info *xi = ac->private;
146 	int type;
147 	u8 tkt_struct_v, blob_struct_v;
148 	struct ceph_x_ticket_handler *th;
149 	void *dp, *dend;
150 	int dlen;
151 	char is_enc;
152 	struct timespec validity;
153 	void *tp, *tpend;
154 	void **ptp;
155 	struct ceph_crypto_key new_session_key = { 0 };
156 	struct ceph_buffer *new_ticket_blob;
157 	unsigned long new_expires, new_renew_after;
158 	u64 new_secret_id;
159 	int ret;
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 	tkt_struct_v = ceph_decode_8(p);
167 	if (tkt_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 	dp = *p + ceph_x_encrypt_offset();
178 	ret = ceph_x_decrypt(secret, p, end);
179 	if (ret < 0)
180 		goto out;
181 	dout(" decrypted %d bytes\n", ret);
182 	dend = dp + ret;
183 
184 	tkt_struct_v = ceph_decode_8(&dp);
185 	if (tkt_struct_v != 1)
186 		goto bad;
187 
188 	ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
189 	if (ret)
190 		goto out;
191 
192 	ceph_decode_timespec(&validity, dp);
193 	dp += sizeof(struct ceph_timespec);
194 	new_expires = get_seconds() + validity.tv_sec;
195 	new_renew_after = new_expires - (validity.tv_sec / 4);
196 	dout(" expires=%lu renew_after=%lu\n", new_expires,
197 	     new_renew_after);
198 
199 	/* ticket blob for service */
200 	ceph_decode_8_safe(p, end, is_enc, bad);
201 	if (is_enc) {
202 		/* encrypted */
203 		tp = *p + ceph_x_encrypt_offset();
204 		ret = ceph_x_decrypt(&th->session_key, p, end);
205 		if (ret < 0)
206 			goto out;
207 		dout(" encrypted ticket, decrypted %d bytes\n", ret);
208 		ptp = &tp;
209 		tpend = tp + ret;
210 	} else {
211 		/* unencrypted */
212 		ptp = p;
213 		tpend = end;
214 	}
215 	ceph_decode_32_safe(ptp, tpend, dlen, bad);
216 	dout(" ticket blob is %d bytes\n", dlen);
217 	ceph_decode_need(ptp, tpend, 1 + sizeof(u64), bad);
218 	blob_struct_v = ceph_decode_8(ptp);
219 	if (blob_struct_v != 1)
220 		goto bad;
221 
222 	new_secret_id = ceph_decode_64(ptp);
223 	ret = ceph_decode_buffer(&new_ticket_blob, ptp, tpend);
224 	if (ret)
225 		goto out;
226 
227 	/* all is well, update our ticket */
228 	ceph_crypto_key_destroy(&th->session_key);
229 	if (th->ticket_blob)
230 		ceph_buffer_put(th->ticket_blob);
231 	th->session_key = new_session_key;
232 	th->ticket_blob = new_ticket_blob;
233 	th->secret_id = new_secret_id;
234 	th->expires = new_expires;
235 	th->renew_after = new_renew_after;
236 	th->have_key = true;
237 	dout(" got ticket service %d (%s) secret_id %lld len %d\n",
238 	     type, ceph_entity_type_name(type), th->secret_id,
239 	     (int)th->ticket_blob->vec.iov_len);
240 	xi->have_keys |= th->service;
241 	return 0;
242 
243 bad:
244 	ret = -EINVAL;
245 out:
246 	ceph_crypto_key_destroy(&new_session_key);
247 	return ret;
248 }
249 
250 static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
251 				    struct ceph_crypto_key *secret,
252 				    void *buf, void *end)
253 {
254 	void *p = buf;
255 	u8 reply_struct_v;
256 	u32 num;
257 	int ret;
258 
259 	ceph_decode_8_safe(&p, end, reply_struct_v, bad);
260 	if (reply_struct_v != 1)
261 		return -EINVAL;
262 
263 	ceph_decode_32_safe(&p, end, num, bad);
264 	dout("%d tickets\n", num);
265 
266 	while (num--) {
267 		ret = process_one_ticket(ac, secret, &p, end);
268 		if (ret)
269 			return ret;
270 	}
271 
272 	return 0;
273 
274 bad:
275 	return -EINVAL;
276 }
277 
278 static void ceph_x_authorizer_cleanup(struct ceph_x_authorizer *au)
279 {
280 	ceph_crypto_key_destroy(&au->session_key);
281 	if (au->buf) {
282 		ceph_buffer_put(au->buf);
283 		au->buf = NULL;
284 	}
285 }
286 
287 static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
288 				   struct ceph_x_ticket_handler *th,
289 				   struct ceph_x_authorizer *au)
290 {
291 	int maxlen;
292 	struct ceph_x_authorize_a *msg_a;
293 	struct ceph_x_authorize_b *msg_b;
294 	void *p, *end;
295 	int ret;
296 	int ticket_blob_len =
297 		(th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
298 
299 	dout("build_authorizer for %s %p\n",
300 	     ceph_entity_type_name(th->service), au);
301 
302 	ceph_crypto_key_destroy(&au->session_key);
303 	ret = ceph_crypto_key_clone(&au->session_key, &th->session_key);
304 	if (ret)
305 		goto out_au;
306 
307 	maxlen = sizeof(*msg_a) + ticket_blob_len +
308 		ceph_x_encrypt_buflen(sizeof(*msg_b));
309 	dout("  need len %d\n", maxlen);
310 	if (au->buf && au->buf->alloc_len < maxlen) {
311 		ceph_buffer_put(au->buf);
312 		au->buf = NULL;
313 	}
314 	if (!au->buf) {
315 		au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
316 		if (!au->buf) {
317 			ret = -ENOMEM;
318 			goto out_au;
319 		}
320 	}
321 	au->service = th->service;
322 	au->secret_id = th->secret_id;
323 
324 	msg_a = au->buf->vec.iov_base;
325 	msg_a->struct_v = 1;
326 	msg_a->global_id = cpu_to_le64(ac->global_id);
327 	msg_a->service_id = cpu_to_le32(th->service);
328 	msg_a->ticket_blob.struct_v = 1;
329 	msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
330 	msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
331 	if (ticket_blob_len) {
332 		memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
333 		       th->ticket_blob->vec.iov_len);
334 	}
335 	dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
336 	     le64_to_cpu(msg_a->ticket_blob.secret_id));
337 
338 	p = msg_a + 1;
339 	p += ticket_blob_len;
340 	end = au->buf->vec.iov_base + au->buf->vec.iov_len;
341 
342 	msg_b = p + ceph_x_encrypt_offset();
343 	msg_b->struct_v = 1;
344 	get_random_bytes(&au->nonce, sizeof(au->nonce));
345 	msg_b->nonce = cpu_to_le64(au->nonce);
346 	ret = ceph_x_encrypt(&au->session_key, p, end - p, sizeof(*msg_b));
347 	if (ret < 0)
348 		goto out_au;
349 
350 	p += ret;
351 	WARN_ON(p > end);
352 	au->buf->vec.iov_len = p - au->buf->vec.iov_base;
353 	dout(" built authorizer nonce %llx len %d\n", au->nonce,
354 	     (int)au->buf->vec.iov_len);
355 	return 0;
356 
357 out_au:
358 	ceph_x_authorizer_cleanup(au);
359 	return ret;
360 }
361 
362 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
363 				void **p, void *end)
364 {
365 	ceph_decode_need(p, end, 1 + sizeof(u64), bad);
366 	ceph_encode_8(p, 1);
367 	ceph_encode_64(p, th->secret_id);
368 	if (th->ticket_blob) {
369 		const char *buf = th->ticket_blob->vec.iov_base;
370 		u32 len = th->ticket_blob->vec.iov_len;
371 
372 		ceph_encode_32_safe(p, end, len, bad);
373 		ceph_encode_copy_safe(p, end, buf, len, bad);
374 	} else {
375 		ceph_encode_32_safe(p, end, 0, bad);
376 	}
377 
378 	return 0;
379 bad:
380 	return -ERANGE;
381 }
382 
383 static bool need_key(struct ceph_x_ticket_handler *th)
384 {
385 	if (!th->have_key)
386 		return true;
387 
388 	return get_seconds() >= th->renew_after;
389 }
390 
391 static bool have_key(struct ceph_x_ticket_handler *th)
392 {
393 	if (th->have_key) {
394 		if (get_seconds() >= th->expires)
395 			th->have_key = false;
396 	}
397 
398 	return th->have_key;
399 }
400 
401 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
402 {
403 	int want = ac->want_keys;
404 	struct ceph_x_info *xi = ac->private;
405 	int service;
406 
407 	*pneed = ac->want_keys & ~(xi->have_keys);
408 
409 	for (service = 1; service <= want; service <<= 1) {
410 		struct ceph_x_ticket_handler *th;
411 
412 		if (!(ac->want_keys & service))
413 			continue;
414 
415 		if (*pneed & service)
416 			continue;
417 
418 		th = get_ticket_handler(ac, service);
419 		if (IS_ERR(th)) {
420 			*pneed |= service;
421 			continue;
422 		}
423 
424 		if (need_key(th))
425 			*pneed |= service;
426 		if (!have_key(th))
427 			xi->have_keys &= ~service;
428 	}
429 }
430 
431 static int ceph_x_build_request(struct ceph_auth_client *ac,
432 				void *buf, void *end)
433 {
434 	struct ceph_x_info *xi = ac->private;
435 	int need;
436 	struct ceph_x_request_header *head = buf;
437 	int ret;
438 	struct ceph_x_ticket_handler *th =
439 		get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
440 
441 	if (IS_ERR(th))
442 		return PTR_ERR(th);
443 
444 	ceph_x_validate_tickets(ac, &need);
445 
446 	dout("build_request want %x have %x need %x\n",
447 	     ac->want_keys, xi->have_keys, need);
448 
449 	if (need & CEPH_ENTITY_TYPE_AUTH) {
450 		struct ceph_x_authenticate *auth = (void *)(head + 1);
451 		void *p = auth + 1;
452 		void *enc_buf = xi->auth_authorizer.enc_buf;
453 		struct ceph_x_challenge_blob *blob = enc_buf +
454 							ceph_x_encrypt_offset();
455 		u64 *u;
456 
457 		if (p > end)
458 			return -ERANGE;
459 
460 		dout(" get_auth_session_key\n");
461 		head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
462 
463 		/* encrypt and hash */
464 		get_random_bytes(&auth->client_challenge, sizeof(u64));
465 		blob->client_challenge = auth->client_challenge;
466 		blob->server_challenge = cpu_to_le64(xi->server_challenge);
467 		ret = ceph_x_encrypt(&xi->secret, enc_buf, CEPHX_AU_ENC_BUF_LEN,
468 				     sizeof(*blob));
469 		if (ret < 0)
470 			return ret;
471 
472 		auth->struct_v = 1;
473 		auth->key = 0;
474 		for (u = (u64 *)enc_buf; u + 1 <= (u64 *)(enc_buf + ret); u++)
475 			auth->key ^= *(__le64 *)u;
476 		dout(" server_challenge %llx client_challenge %llx key %llx\n",
477 		     xi->server_challenge, le64_to_cpu(auth->client_challenge),
478 		     le64_to_cpu(auth->key));
479 
480 		/* now encode the old ticket if exists */
481 		ret = ceph_x_encode_ticket(th, &p, end);
482 		if (ret < 0)
483 			return ret;
484 
485 		return p - buf;
486 	}
487 
488 	if (need) {
489 		void *p = head + 1;
490 		struct ceph_x_service_ticket_request *req;
491 
492 		if (p > end)
493 			return -ERANGE;
494 		head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
495 
496 		ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
497 		if (ret)
498 			return ret;
499 		ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
500 				 xi->auth_authorizer.buf->vec.iov_len);
501 
502 		req = p;
503 		req->keys = cpu_to_le32(need);
504 		p += sizeof(*req);
505 		return p - buf;
506 	}
507 
508 	return 0;
509 }
510 
511 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
512 			       void *buf, void *end)
513 {
514 	struct ceph_x_info *xi = ac->private;
515 	struct ceph_x_reply_header *head = buf;
516 	struct ceph_x_ticket_handler *th;
517 	int len = end - buf;
518 	int op;
519 	int ret;
520 
521 	if (result)
522 		return result;  /* XXX hmm? */
523 
524 	if (xi->starting) {
525 		/* it's a hello */
526 		struct ceph_x_server_challenge *sc = buf;
527 
528 		if (len != sizeof(*sc))
529 			return -EINVAL;
530 		xi->server_challenge = le64_to_cpu(sc->server_challenge);
531 		dout("handle_reply got server challenge %llx\n",
532 		     xi->server_challenge);
533 		xi->starting = false;
534 		xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
535 		return -EAGAIN;
536 	}
537 
538 	op = le16_to_cpu(head->op);
539 	result = le32_to_cpu(head->result);
540 	dout("handle_reply op %d result %d\n", op, result);
541 	switch (op) {
542 	case CEPHX_GET_AUTH_SESSION_KEY:
543 		/* verify auth key */
544 		ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
545 					       buf + sizeof(*head), end);
546 		break;
547 
548 	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
549 		th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
550 		if (IS_ERR(th))
551 			return PTR_ERR(th);
552 		ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
553 					       buf + sizeof(*head), end);
554 		break;
555 
556 	default:
557 		return -EINVAL;
558 	}
559 	if (ret)
560 		return ret;
561 	if (ac->want_keys == xi->have_keys)
562 		return 0;
563 	return -EAGAIN;
564 }
565 
566 static void ceph_x_destroy_authorizer(struct ceph_authorizer *a)
567 {
568 	struct ceph_x_authorizer *au = (void *)a;
569 
570 	ceph_x_authorizer_cleanup(au);
571 	kfree(au);
572 }
573 
574 static int ceph_x_create_authorizer(
575 	struct ceph_auth_client *ac, int peer_type,
576 	struct ceph_auth_handshake *auth)
577 {
578 	struct ceph_x_authorizer *au;
579 	struct ceph_x_ticket_handler *th;
580 	int ret;
581 
582 	th = get_ticket_handler(ac, peer_type);
583 	if (IS_ERR(th))
584 		return PTR_ERR(th);
585 
586 	au = kzalloc(sizeof(*au), GFP_NOFS);
587 	if (!au)
588 		return -ENOMEM;
589 
590 	au->base.destroy = ceph_x_destroy_authorizer;
591 
592 	ret = ceph_x_build_authorizer(ac, th, au);
593 	if (ret) {
594 		kfree(au);
595 		return ret;
596 	}
597 
598 	auth->authorizer = (struct ceph_authorizer *) au;
599 	auth->authorizer_buf = au->buf->vec.iov_base;
600 	auth->authorizer_buf_len = au->buf->vec.iov_len;
601 	auth->authorizer_reply_buf = au->enc_buf;
602 	auth->authorizer_reply_buf_len = CEPHX_AU_ENC_BUF_LEN;
603 	auth->sign_message = ac->ops->sign_message;
604 	auth->check_message_signature = ac->ops->check_message_signature;
605 
606 	return 0;
607 }
608 
609 static int ceph_x_update_authorizer(
610 	struct ceph_auth_client *ac, int peer_type,
611 	struct ceph_auth_handshake *auth)
612 {
613 	struct ceph_x_authorizer *au;
614 	struct ceph_x_ticket_handler *th;
615 
616 	th = get_ticket_handler(ac, peer_type);
617 	if (IS_ERR(th))
618 		return PTR_ERR(th);
619 
620 	au = (struct ceph_x_authorizer *)auth->authorizer;
621 	if (au->secret_id < th->secret_id) {
622 		dout("ceph_x_update_authorizer service %u secret %llu < %llu\n",
623 		     au->service, au->secret_id, th->secret_id);
624 		return ceph_x_build_authorizer(ac, th, au);
625 	}
626 	return 0;
627 }
628 
629 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
630 					  struct ceph_authorizer *a)
631 {
632 	struct ceph_x_authorizer *au = (void *)a;
633 	void *p = au->enc_buf;
634 	struct ceph_x_authorize_reply *reply = p + ceph_x_encrypt_offset();
635 	int ret;
636 
637 	ret = ceph_x_decrypt(&au->session_key, &p, p + CEPHX_AU_ENC_BUF_LEN);
638 	if (ret < 0)
639 		return ret;
640 	if (ret != sizeof(*reply))
641 		return -EPERM;
642 
643 	if (au->nonce + 1 != le64_to_cpu(reply->nonce_plus_one))
644 		ret = -EPERM;
645 	else
646 		ret = 0;
647 	dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
648 	     au->nonce, le64_to_cpu(reply->nonce_plus_one), ret);
649 	return ret;
650 }
651 
652 static void ceph_x_reset(struct ceph_auth_client *ac)
653 {
654 	struct ceph_x_info *xi = ac->private;
655 
656 	dout("reset\n");
657 	xi->starting = true;
658 	xi->server_challenge = 0;
659 }
660 
661 static void ceph_x_destroy(struct ceph_auth_client *ac)
662 {
663 	struct ceph_x_info *xi = ac->private;
664 	struct rb_node *p;
665 
666 	dout("ceph_x_destroy %p\n", ac);
667 	ceph_crypto_key_destroy(&xi->secret);
668 
669 	while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
670 		struct ceph_x_ticket_handler *th =
671 			rb_entry(p, struct ceph_x_ticket_handler, node);
672 		remove_ticket_handler(ac, th);
673 	}
674 
675 	ceph_x_authorizer_cleanup(&xi->auth_authorizer);
676 
677 	kfree(ac->private);
678 	ac->private = NULL;
679 }
680 
681 static void invalidate_ticket(struct ceph_auth_client *ac, int peer_type)
682 {
683 	struct ceph_x_ticket_handler *th;
684 
685 	th = get_ticket_handler(ac, peer_type);
686 	if (!IS_ERR(th))
687 		th->have_key = false;
688 }
689 
690 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
691 					 int peer_type)
692 {
693 	/*
694 	 * We are to invalidate a service ticket in the hopes of
695 	 * getting a new, hopefully more valid, one.  But, we won't get
696 	 * it unless our AUTH ticket is good, so invalidate AUTH ticket
697 	 * as well, just in case.
698 	 */
699 	invalidate_ticket(ac, peer_type);
700 	invalidate_ticket(ac, CEPH_ENTITY_TYPE_AUTH);
701 }
702 
703 static int calc_signature(struct ceph_x_authorizer *au, struct ceph_msg *msg,
704 			  __le64 *psig)
705 {
706 	void *enc_buf = au->enc_buf;
707 	struct {
708 		__le32 len;
709 		__le32 header_crc;
710 		__le32 front_crc;
711 		__le32 middle_crc;
712 		__le32 data_crc;
713 	} __packed *sigblock = enc_buf + ceph_x_encrypt_offset();
714 	int ret;
715 
716 	sigblock->len = cpu_to_le32(4*sizeof(u32));
717 	sigblock->header_crc = msg->hdr.crc;
718 	sigblock->front_crc = msg->footer.front_crc;
719 	sigblock->middle_crc = msg->footer.middle_crc;
720 	sigblock->data_crc =  msg->footer.data_crc;
721 	ret = ceph_x_encrypt(&au->session_key, enc_buf, CEPHX_AU_ENC_BUF_LEN,
722 			     sizeof(*sigblock));
723 	if (ret < 0)
724 		return ret;
725 
726 	*psig = *(__le64 *)(enc_buf + sizeof(u32));
727 	return 0;
728 }
729 
730 static int ceph_x_sign_message(struct ceph_auth_handshake *auth,
731 			       struct ceph_msg *msg)
732 {
733 	__le64 sig;
734 	int ret;
735 
736 	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
737 		return 0;
738 
739 	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
740 			     msg, &sig);
741 	if (ret)
742 		return ret;
743 
744 	msg->footer.sig = sig;
745 	msg->footer.flags |= CEPH_MSG_FOOTER_SIGNED;
746 	return 0;
747 }
748 
749 static int ceph_x_check_message_signature(struct ceph_auth_handshake *auth,
750 					  struct ceph_msg *msg)
751 {
752 	__le64 sig_check;
753 	int ret;
754 
755 	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
756 		return 0;
757 
758 	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
759 			     msg, &sig_check);
760 	if (ret)
761 		return ret;
762 	if (sig_check == msg->footer.sig)
763 		return 0;
764 	if (msg->footer.flags & CEPH_MSG_FOOTER_SIGNED)
765 		dout("ceph_x_check_message_signature %p has signature %llx "
766 		     "expect %llx\n", msg, msg->footer.sig, sig_check);
767 	else
768 		dout("ceph_x_check_message_signature %p sender did not set "
769 		     "CEPH_MSG_FOOTER_SIGNED\n", msg);
770 	return -EBADMSG;
771 }
772 
773 static const struct ceph_auth_client_ops ceph_x_ops = {
774 	.name = "x",
775 	.is_authenticated = ceph_x_is_authenticated,
776 	.should_authenticate = ceph_x_should_authenticate,
777 	.build_request = ceph_x_build_request,
778 	.handle_reply = ceph_x_handle_reply,
779 	.create_authorizer = ceph_x_create_authorizer,
780 	.update_authorizer = ceph_x_update_authorizer,
781 	.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
782 	.invalidate_authorizer = ceph_x_invalidate_authorizer,
783 	.reset =  ceph_x_reset,
784 	.destroy = ceph_x_destroy,
785 	.sign_message = ceph_x_sign_message,
786 	.check_message_signature = ceph_x_check_message_signature,
787 };
788 
789 
790 int ceph_x_init(struct ceph_auth_client *ac)
791 {
792 	struct ceph_x_info *xi;
793 	int ret;
794 
795 	dout("ceph_x_init %p\n", ac);
796 	ret = -ENOMEM;
797 	xi = kzalloc(sizeof(*xi), GFP_NOFS);
798 	if (!xi)
799 		goto out;
800 
801 	ret = -EINVAL;
802 	if (!ac->key) {
803 		pr_err("no secret set (for auth_x protocol)\n");
804 		goto out_nomem;
805 	}
806 
807 	ret = ceph_crypto_key_clone(&xi->secret, ac->key);
808 	if (ret < 0) {
809 		pr_err("cannot clone key: %d\n", ret);
810 		goto out_nomem;
811 	}
812 
813 	xi->starting = true;
814 	xi->ticket_handlers = RB_ROOT;
815 
816 	ac->protocol = CEPH_AUTH_CEPHX;
817 	ac->private = xi;
818 	ac->ops = &ceph_x_ops;
819 	return 0;
820 
821 out_nomem:
822 	kfree(xi);
823 out:
824 	return ret;
825 }
826 
827 
828