xref: /openbmc/linux/net/ceph/auth_x.c (revision 9b93eb47)
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/ceph_features.h>
13 #include <linux/ceph/libceph.h>
14 #include <linux/ceph/messenger.h>
15 
16 #include "crypto.h"
17 #include "auth_x.h"
18 #include "auth_x_protocol.h"
19 
20 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
21 
22 static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
23 {
24 	struct ceph_x_info *xi = ac->private;
25 	int need;
26 
27 	ceph_x_validate_tickets(ac, &need);
28 	dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
29 	     ac->want_keys, need, xi->have_keys);
30 	return (ac->want_keys & xi->have_keys) == ac->want_keys;
31 }
32 
33 static int ceph_x_should_authenticate(struct ceph_auth_client *ac)
34 {
35 	struct ceph_x_info *xi = ac->private;
36 	int need;
37 
38 	ceph_x_validate_tickets(ac, &need);
39 	dout("ceph_x_should_authenticate want=%d need=%d have=%d\n",
40 	     ac->want_keys, need, xi->have_keys);
41 	return need != 0;
42 }
43 
44 static int ceph_x_encrypt_offset(void)
45 {
46 	return sizeof(u32) + sizeof(struct ceph_x_encrypt_header);
47 }
48 
49 static int ceph_x_encrypt_buflen(int ilen)
50 {
51 	return ceph_x_encrypt_offset() + ilen + 16;
52 }
53 
54 static int ceph_x_encrypt(struct ceph_crypto_key *secret, void *buf,
55 			  int buf_len, int plaintext_len)
56 {
57 	struct ceph_x_encrypt_header *hdr = buf + sizeof(u32);
58 	int ciphertext_len;
59 	int ret;
60 
61 	hdr->struct_v = 1;
62 	hdr->magic = cpu_to_le64(CEPHX_ENC_MAGIC);
63 
64 	ret = ceph_crypt(secret, true, buf + sizeof(u32), buf_len - sizeof(u32),
65 			 plaintext_len + sizeof(struct ceph_x_encrypt_header),
66 			 &ciphertext_len);
67 	if (ret)
68 		return ret;
69 
70 	ceph_encode_32(&buf, ciphertext_len);
71 	return sizeof(u32) + ciphertext_len;
72 }
73 
74 static int __ceph_x_decrypt(struct ceph_crypto_key *secret, void *p,
75 			    int ciphertext_len)
76 {
77 	struct ceph_x_encrypt_header *hdr = p;
78 	int plaintext_len;
79 	int ret;
80 
81 	ret = ceph_crypt(secret, false, p, ciphertext_len, ciphertext_len,
82 			 &plaintext_len);
83 	if (ret)
84 		return ret;
85 
86 	if (le64_to_cpu(hdr->magic) != CEPHX_ENC_MAGIC) {
87 		pr_err("%s bad magic\n", __func__);
88 		return -EINVAL;
89 	}
90 
91 	return plaintext_len - sizeof(*hdr);
92 }
93 
94 static int ceph_x_decrypt(struct ceph_crypto_key *secret, void **p, void *end)
95 {
96 	int ciphertext_len;
97 	int ret;
98 
99 	ceph_decode_32_safe(p, end, ciphertext_len, e_inval);
100 	ceph_decode_need(p, end, ciphertext_len, e_inval);
101 
102 	ret = __ceph_x_decrypt(secret, *p, ciphertext_len);
103 	if (ret < 0)
104 		return ret;
105 
106 	*p += ciphertext_len;
107 	return ret;
108 
109 e_inval:
110 	return -EINVAL;
111 }
112 
113 /*
114  * get existing (or insert new) ticket handler
115  */
116 static struct ceph_x_ticket_handler *
117 get_ticket_handler(struct ceph_auth_client *ac, int service)
118 {
119 	struct ceph_x_ticket_handler *th;
120 	struct ceph_x_info *xi = ac->private;
121 	struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
122 
123 	while (*p) {
124 		parent = *p;
125 		th = rb_entry(parent, struct ceph_x_ticket_handler, node);
126 		if (service < th->service)
127 			p = &(*p)->rb_left;
128 		else if (service > th->service)
129 			p = &(*p)->rb_right;
130 		else
131 			return th;
132 	}
133 
134 	/* add it */
135 	th = kzalloc(sizeof(*th), GFP_NOFS);
136 	if (!th)
137 		return ERR_PTR(-ENOMEM);
138 	th->service = service;
139 	rb_link_node(&th->node, parent, p);
140 	rb_insert_color(&th->node, &xi->ticket_handlers);
141 	return th;
142 }
143 
144 static void remove_ticket_handler(struct ceph_auth_client *ac,
145 				  struct ceph_x_ticket_handler *th)
146 {
147 	struct ceph_x_info *xi = ac->private;
148 
149 	dout("remove_ticket_handler %p %d\n", th, th->service);
150 	rb_erase(&th->node, &xi->ticket_handlers);
151 	ceph_crypto_key_destroy(&th->session_key);
152 	if (th->ticket_blob)
153 		ceph_buffer_put(th->ticket_blob);
154 	kfree(th);
155 }
156 
157 static int process_one_ticket(struct ceph_auth_client *ac,
158 			      struct ceph_crypto_key *secret,
159 			      void **p, void *end)
160 {
161 	struct ceph_x_info *xi = ac->private;
162 	int type;
163 	u8 tkt_struct_v, blob_struct_v;
164 	struct ceph_x_ticket_handler *th;
165 	void *dp, *dend;
166 	int dlen;
167 	char is_enc;
168 	struct timespec64 validity;
169 	void *tp, *tpend;
170 	void **ptp;
171 	struct ceph_crypto_key new_session_key = { 0 };
172 	struct ceph_buffer *new_ticket_blob;
173 	time64_t new_expires, new_renew_after;
174 	u64 new_secret_id;
175 	int ret;
176 
177 	ceph_decode_need(p, end, sizeof(u32) + 1, bad);
178 
179 	type = ceph_decode_32(p);
180 	dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
181 
182 	tkt_struct_v = ceph_decode_8(p);
183 	if (tkt_struct_v != 1)
184 		goto bad;
185 
186 	th = get_ticket_handler(ac, type);
187 	if (IS_ERR(th)) {
188 		ret = PTR_ERR(th);
189 		goto out;
190 	}
191 
192 	/* blob for me */
193 	dp = *p + ceph_x_encrypt_offset();
194 	ret = ceph_x_decrypt(secret, p, end);
195 	if (ret < 0)
196 		goto out;
197 	dout(" decrypted %d bytes\n", ret);
198 	dend = dp + ret;
199 
200 	tkt_struct_v = ceph_decode_8(&dp);
201 	if (tkt_struct_v != 1)
202 		goto bad;
203 
204 	ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
205 	if (ret)
206 		goto out;
207 
208 	ceph_decode_timespec64(&validity, dp);
209 	dp += sizeof(struct ceph_timespec);
210 	new_expires = ktime_get_real_seconds() + validity.tv_sec;
211 	new_renew_after = new_expires - (validity.tv_sec / 4);
212 	dout(" expires=%llu renew_after=%llu\n", new_expires,
213 	     new_renew_after);
214 
215 	/* ticket blob for service */
216 	ceph_decode_8_safe(p, end, is_enc, bad);
217 	if (is_enc) {
218 		/* encrypted */
219 		tp = *p + ceph_x_encrypt_offset();
220 		ret = ceph_x_decrypt(&th->session_key, p, end);
221 		if (ret < 0)
222 			goto out;
223 		dout(" encrypted ticket, decrypted %d bytes\n", ret);
224 		ptp = &tp;
225 		tpend = tp + ret;
226 	} else {
227 		/* unencrypted */
228 		ptp = p;
229 		tpend = end;
230 	}
231 	ceph_decode_32_safe(ptp, tpend, dlen, bad);
232 	dout(" ticket blob is %d bytes\n", dlen);
233 	ceph_decode_need(ptp, tpend, 1 + sizeof(u64), bad);
234 	blob_struct_v = ceph_decode_8(ptp);
235 	if (blob_struct_v != 1)
236 		goto bad;
237 
238 	new_secret_id = ceph_decode_64(ptp);
239 	ret = ceph_decode_buffer(&new_ticket_blob, ptp, tpend);
240 	if (ret)
241 		goto out;
242 
243 	/* all is well, update our ticket */
244 	ceph_crypto_key_destroy(&th->session_key);
245 	if (th->ticket_blob)
246 		ceph_buffer_put(th->ticket_blob);
247 	th->session_key = new_session_key;
248 	th->ticket_blob = new_ticket_blob;
249 	th->secret_id = new_secret_id;
250 	th->expires = new_expires;
251 	th->renew_after = new_renew_after;
252 	th->have_key = true;
253 	dout(" got ticket service %d (%s) secret_id %lld len %d\n",
254 	     type, ceph_entity_type_name(type), th->secret_id,
255 	     (int)th->ticket_blob->vec.iov_len);
256 	xi->have_keys |= th->service;
257 	return 0;
258 
259 bad:
260 	ret = -EINVAL;
261 out:
262 	ceph_crypto_key_destroy(&new_session_key);
263 	return ret;
264 }
265 
266 static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
267 				    struct ceph_crypto_key *secret,
268 				    void *buf, void *end)
269 {
270 	void *p = buf;
271 	u8 reply_struct_v;
272 	u32 num;
273 	int ret;
274 
275 	ceph_decode_8_safe(&p, end, reply_struct_v, bad);
276 	if (reply_struct_v != 1)
277 		return -EINVAL;
278 
279 	ceph_decode_32_safe(&p, end, num, bad);
280 	dout("%d tickets\n", num);
281 
282 	while (num--) {
283 		ret = process_one_ticket(ac, secret, &p, end);
284 		if (ret)
285 			return ret;
286 	}
287 
288 	return 0;
289 
290 bad:
291 	return -EINVAL;
292 }
293 
294 /*
295  * Encode and encrypt the second part (ceph_x_authorize_b) of the
296  * authorizer.  The first part (ceph_x_authorize_a) should already be
297  * encoded.
298  */
299 static int encrypt_authorizer(struct ceph_x_authorizer *au,
300 			      u64 *server_challenge)
301 {
302 	struct ceph_x_authorize_a *msg_a;
303 	struct ceph_x_authorize_b *msg_b;
304 	void *p, *end;
305 	int ret;
306 
307 	msg_a = au->buf->vec.iov_base;
308 	WARN_ON(msg_a->ticket_blob.secret_id != cpu_to_le64(au->secret_id));
309 	p = (void *)(msg_a + 1) + le32_to_cpu(msg_a->ticket_blob.blob_len);
310 	end = au->buf->vec.iov_base + au->buf->vec.iov_len;
311 
312 	msg_b = p + ceph_x_encrypt_offset();
313 	msg_b->struct_v = 2;
314 	msg_b->nonce = cpu_to_le64(au->nonce);
315 	if (server_challenge) {
316 		msg_b->have_challenge = 1;
317 		msg_b->server_challenge_plus_one =
318 		    cpu_to_le64(*server_challenge + 1);
319 	} else {
320 		msg_b->have_challenge = 0;
321 		msg_b->server_challenge_plus_one = 0;
322 	}
323 
324 	ret = ceph_x_encrypt(&au->session_key, p, end - p, sizeof(*msg_b));
325 	if (ret < 0)
326 		return ret;
327 
328 	p += ret;
329 	if (server_challenge) {
330 		WARN_ON(p != end);
331 	} else {
332 		WARN_ON(p > end);
333 		au->buf->vec.iov_len = p - au->buf->vec.iov_base;
334 	}
335 
336 	return 0;
337 }
338 
339 static void ceph_x_authorizer_cleanup(struct ceph_x_authorizer *au)
340 {
341 	ceph_crypto_key_destroy(&au->session_key);
342 	if (au->buf) {
343 		ceph_buffer_put(au->buf);
344 		au->buf = NULL;
345 	}
346 }
347 
348 static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
349 				   struct ceph_x_ticket_handler *th,
350 				   struct ceph_x_authorizer *au)
351 {
352 	int maxlen;
353 	struct ceph_x_authorize_a *msg_a;
354 	struct ceph_x_authorize_b *msg_b;
355 	int ret;
356 	int ticket_blob_len =
357 		(th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
358 
359 	dout("build_authorizer for %s %p\n",
360 	     ceph_entity_type_name(th->service), au);
361 
362 	ceph_crypto_key_destroy(&au->session_key);
363 	ret = ceph_crypto_key_clone(&au->session_key, &th->session_key);
364 	if (ret)
365 		goto out_au;
366 
367 	maxlen = sizeof(*msg_a) + ticket_blob_len +
368 		ceph_x_encrypt_buflen(sizeof(*msg_b));
369 	dout("  need len %d\n", maxlen);
370 	if (au->buf && au->buf->alloc_len < maxlen) {
371 		ceph_buffer_put(au->buf);
372 		au->buf = NULL;
373 	}
374 	if (!au->buf) {
375 		au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
376 		if (!au->buf) {
377 			ret = -ENOMEM;
378 			goto out_au;
379 		}
380 	}
381 	au->service = th->service;
382 	au->secret_id = th->secret_id;
383 
384 	msg_a = au->buf->vec.iov_base;
385 	msg_a->struct_v = 1;
386 	msg_a->global_id = cpu_to_le64(ac->global_id);
387 	msg_a->service_id = cpu_to_le32(th->service);
388 	msg_a->ticket_blob.struct_v = 1;
389 	msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
390 	msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
391 	if (ticket_blob_len) {
392 		memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
393 		       th->ticket_blob->vec.iov_len);
394 	}
395 	dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
396 	     le64_to_cpu(msg_a->ticket_blob.secret_id));
397 
398 	get_random_bytes(&au->nonce, sizeof(au->nonce));
399 	ret = encrypt_authorizer(au, NULL);
400 	if (ret) {
401 		pr_err("failed to encrypt authorizer: %d", ret);
402 		goto out_au;
403 	}
404 
405 	dout(" built authorizer nonce %llx len %d\n", au->nonce,
406 	     (int)au->buf->vec.iov_len);
407 	return 0;
408 
409 out_au:
410 	ceph_x_authorizer_cleanup(au);
411 	return ret;
412 }
413 
414 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
415 				void **p, void *end)
416 {
417 	ceph_decode_need(p, end, 1 + sizeof(u64), bad);
418 	ceph_encode_8(p, 1);
419 	ceph_encode_64(p, th->secret_id);
420 	if (th->ticket_blob) {
421 		const char *buf = th->ticket_blob->vec.iov_base;
422 		u32 len = th->ticket_blob->vec.iov_len;
423 
424 		ceph_encode_32_safe(p, end, len, bad);
425 		ceph_encode_copy_safe(p, end, buf, len, bad);
426 	} else {
427 		ceph_encode_32_safe(p, end, 0, bad);
428 	}
429 
430 	return 0;
431 bad:
432 	return -ERANGE;
433 }
434 
435 static bool need_key(struct ceph_x_ticket_handler *th)
436 {
437 	if (!th->have_key)
438 		return true;
439 
440 	return ktime_get_real_seconds() >= th->renew_after;
441 }
442 
443 static bool have_key(struct ceph_x_ticket_handler *th)
444 {
445 	if (th->have_key) {
446 		if (ktime_get_real_seconds() >= th->expires)
447 			th->have_key = false;
448 	}
449 
450 	return th->have_key;
451 }
452 
453 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
454 {
455 	int want = ac->want_keys;
456 	struct ceph_x_info *xi = ac->private;
457 	int service;
458 
459 	*pneed = ac->want_keys & ~(xi->have_keys);
460 
461 	for (service = 1; service <= want; service <<= 1) {
462 		struct ceph_x_ticket_handler *th;
463 
464 		if (!(ac->want_keys & service))
465 			continue;
466 
467 		if (*pneed & service)
468 			continue;
469 
470 		th = get_ticket_handler(ac, service);
471 		if (IS_ERR(th)) {
472 			*pneed |= service;
473 			continue;
474 		}
475 
476 		if (need_key(th))
477 			*pneed |= service;
478 		if (!have_key(th))
479 			xi->have_keys &= ~service;
480 	}
481 }
482 
483 static int ceph_x_build_request(struct ceph_auth_client *ac,
484 				void *buf, void *end)
485 {
486 	struct ceph_x_info *xi = ac->private;
487 	int need;
488 	struct ceph_x_request_header *head = buf;
489 	int ret;
490 	struct ceph_x_ticket_handler *th =
491 		get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
492 
493 	if (IS_ERR(th))
494 		return PTR_ERR(th);
495 
496 	ceph_x_validate_tickets(ac, &need);
497 
498 	dout("build_request want %x have %x need %x\n",
499 	     ac->want_keys, xi->have_keys, need);
500 
501 	if (need & CEPH_ENTITY_TYPE_AUTH) {
502 		struct ceph_x_authenticate *auth = (void *)(head + 1);
503 		void *p = auth + 1;
504 		void *enc_buf = xi->auth_authorizer.enc_buf;
505 		struct ceph_x_challenge_blob *blob = enc_buf +
506 							ceph_x_encrypt_offset();
507 		u64 *u;
508 
509 		if (p > end)
510 			return -ERANGE;
511 
512 		dout(" get_auth_session_key\n");
513 		head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
514 
515 		/* encrypt and hash */
516 		get_random_bytes(&auth->client_challenge, sizeof(u64));
517 		blob->client_challenge = auth->client_challenge;
518 		blob->server_challenge = cpu_to_le64(xi->server_challenge);
519 		ret = ceph_x_encrypt(&xi->secret, enc_buf, CEPHX_AU_ENC_BUF_LEN,
520 				     sizeof(*blob));
521 		if (ret < 0)
522 			return ret;
523 
524 		auth->struct_v = 1;
525 		auth->key = 0;
526 		for (u = (u64 *)enc_buf; u + 1 <= (u64 *)(enc_buf + ret); u++)
527 			auth->key ^= *(__le64 *)u;
528 		dout(" server_challenge %llx client_challenge %llx key %llx\n",
529 		     xi->server_challenge, le64_to_cpu(auth->client_challenge),
530 		     le64_to_cpu(auth->key));
531 
532 		/* now encode the old ticket if exists */
533 		ret = ceph_x_encode_ticket(th, &p, end);
534 		if (ret < 0)
535 			return ret;
536 
537 		return p - buf;
538 	}
539 
540 	if (need) {
541 		void *p = head + 1;
542 		struct ceph_x_service_ticket_request *req;
543 
544 		if (p > end)
545 			return -ERANGE;
546 		head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
547 
548 		ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
549 		if (ret)
550 			return ret;
551 		ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
552 				 xi->auth_authorizer.buf->vec.iov_len);
553 
554 		req = p;
555 		req->keys = cpu_to_le32(need);
556 		p += sizeof(*req);
557 		return p - buf;
558 	}
559 
560 	return 0;
561 }
562 
563 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
564 			       void *buf, void *end)
565 {
566 	struct ceph_x_info *xi = ac->private;
567 	struct ceph_x_reply_header *head = buf;
568 	struct ceph_x_ticket_handler *th;
569 	int len = end - buf;
570 	int op;
571 	int ret;
572 
573 	if (result)
574 		return result;  /* XXX hmm? */
575 
576 	if (xi->starting) {
577 		/* it's a hello */
578 		struct ceph_x_server_challenge *sc = buf;
579 
580 		if (len != sizeof(*sc))
581 			return -EINVAL;
582 		xi->server_challenge = le64_to_cpu(sc->server_challenge);
583 		dout("handle_reply got server challenge %llx\n",
584 		     xi->server_challenge);
585 		xi->starting = false;
586 		xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
587 		return -EAGAIN;
588 	}
589 
590 	op = le16_to_cpu(head->op);
591 	result = le32_to_cpu(head->result);
592 	dout("handle_reply op %d result %d\n", op, result);
593 	switch (op) {
594 	case CEPHX_GET_AUTH_SESSION_KEY:
595 		/* verify auth key */
596 		ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
597 					       buf + sizeof(*head), end);
598 		break;
599 
600 	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
601 		th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
602 		if (IS_ERR(th))
603 			return PTR_ERR(th);
604 		ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
605 					       buf + sizeof(*head), end);
606 		break;
607 
608 	default:
609 		return -EINVAL;
610 	}
611 	if (ret)
612 		return ret;
613 	if (ac->want_keys == xi->have_keys)
614 		return 0;
615 	return -EAGAIN;
616 }
617 
618 static void ceph_x_destroy_authorizer(struct ceph_authorizer *a)
619 {
620 	struct ceph_x_authorizer *au = (void *)a;
621 
622 	ceph_x_authorizer_cleanup(au);
623 	kfree(au);
624 }
625 
626 static int ceph_x_create_authorizer(
627 	struct ceph_auth_client *ac, int peer_type,
628 	struct ceph_auth_handshake *auth)
629 {
630 	struct ceph_x_authorizer *au;
631 	struct ceph_x_ticket_handler *th;
632 	int ret;
633 
634 	th = get_ticket_handler(ac, peer_type);
635 	if (IS_ERR(th))
636 		return PTR_ERR(th);
637 
638 	au = kzalloc(sizeof(*au), GFP_NOFS);
639 	if (!au)
640 		return -ENOMEM;
641 
642 	au->base.destroy = ceph_x_destroy_authorizer;
643 
644 	ret = ceph_x_build_authorizer(ac, th, au);
645 	if (ret) {
646 		kfree(au);
647 		return ret;
648 	}
649 
650 	auth->authorizer = (struct ceph_authorizer *) au;
651 	auth->authorizer_buf = au->buf->vec.iov_base;
652 	auth->authorizer_buf_len = au->buf->vec.iov_len;
653 	auth->authorizer_reply_buf = au->enc_buf;
654 	auth->authorizer_reply_buf_len = CEPHX_AU_ENC_BUF_LEN;
655 	auth->sign_message = ac->ops->sign_message;
656 	auth->check_message_signature = ac->ops->check_message_signature;
657 
658 	return 0;
659 }
660 
661 static int ceph_x_update_authorizer(
662 	struct ceph_auth_client *ac, int peer_type,
663 	struct ceph_auth_handshake *auth)
664 {
665 	struct ceph_x_authorizer *au;
666 	struct ceph_x_ticket_handler *th;
667 
668 	th = get_ticket_handler(ac, peer_type);
669 	if (IS_ERR(th))
670 		return PTR_ERR(th);
671 
672 	au = (struct ceph_x_authorizer *)auth->authorizer;
673 	if (au->secret_id < th->secret_id) {
674 		dout("ceph_x_update_authorizer service %u secret %llu < %llu\n",
675 		     au->service, au->secret_id, th->secret_id);
676 		return ceph_x_build_authorizer(ac, th, au);
677 	}
678 	return 0;
679 }
680 
681 static int decrypt_authorize_challenge(struct ceph_x_authorizer *au,
682 				       void *challenge_buf,
683 				       int challenge_buf_len,
684 				       u64 *server_challenge)
685 {
686 	struct ceph_x_authorize_challenge *ch =
687 	    challenge_buf + sizeof(struct ceph_x_encrypt_header);
688 	int ret;
689 
690 	/* no leading len */
691 	ret = __ceph_x_decrypt(&au->session_key, challenge_buf,
692 			       challenge_buf_len);
693 	if (ret < 0)
694 		return ret;
695 	if (ret < sizeof(*ch)) {
696 		pr_err("bad size %d for ceph_x_authorize_challenge\n", ret);
697 		return -EINVAL;
698 	}
699 
700 	*server_challenge = le64_to_cpu(ch->server_challenge);
701 	return 0;
702 }
703 
704 static int ceph_x_add_authorizer_challenge(struct ceph_auth_client *ac,
705 					   struct ceph_authorizer *a,
706 					   void *challenge_buf,
707 					   int challenge_buf_len)
708 {
709 	struct ceph_x_authorizer *au = (void *)a;
710 	u64 server_challenge;
711 	int ret;
712 
713 	ret = decrypt_authorize_challenge(au, challenge_buf, challenge_buf_len,
714 					  &server_challenge);
715 	if (ret) {
716 		pr_err("failed to decrypt authorize challenge: %d", ret);
717 		return ret;
718 	}
719 
720 	ret = encrypt_authorizer(au, &server_challenge);
721 	if (ret) {
722 		pr_err("failed to encrypt authorizer w/ challenge: %d", ret);
723 		return ret;
724 	}
725 
726 	return 0;
727 }
728 
729 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
730 					  struct ceph_authorizer *a)
731 {
732 	struct ceph_x_authorizer *au = (void *)a;
733 	void *p = au->enc_buf;
734 	struct ceph_x_authorize_reply *reply = p + ceph_x_encrypt_offset();
735 	int ret;
736 
737 	ret = ceph_x_decrypt(&au->session_key, &p, p + CEPHX_AU_ENC_BUF_LEN);
738 	if (ret < 0)
739 		return ret;
740 	if (ret < sizeof(*reply)) {
741 		pr_err("bad size %d for ceph_x_authorize_reply\n", ret);
742 		return -EINVAL;
743 	}
744 
745 	if (au->nonce + 1 != le64_to_cpu(reply->nonce_plus_one))
746 		ret = -EPERM;
747 	else
748 		ret = 0;
749 	dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
750 	     au->nonce, le64_to_cpu(reply->nonce_plus_one), ret);
751 	return ret;
752 }
753 
754 static void ceph_x_reset(struct ceph_auth_client *ac)
755 {
756 	struct ceph_x_info *xi = ac->private;
757 
758 	dout("reset\n");
759 	xi->starting = true;
760 	xi->server_challenge = 0;
761 }
762 
763 static void ceph_x_destroy(struct ceph_auth_client *ac)
764 {
765 	struct ceph_x_info *xi = ac->private;
766 	struct rb_node *p;
767 
768 	dout("ceph_x_destroy %p\n", ac);
769 	ceph_crypto_key_destroy(&xi->secret);
770 
771 	while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
772 		struct ceph_x_ticket_handler *th =
773 			rb_entry(p, struct ceph_x_ticket_handler, node);
774 		remove_ticket_handler(ac, th);
775 	}
776 
777 	ceph_x_authorizer_cleanup(&xi->auth_authorizer);
778 
779 	kfree(ac->private);
780 	ac->private = NULL;
781 }
782 
783 static void invalidate_ticket(struct ceph_auth_client *ac, int peer_type)
784 {
785 	struct ceph_x_ticket_handler *th;
786 
787 	th = get_ticket_handler(ac, peer_type);
788 	if (!IS_ERR(th))
789 		th->have_key = false;
790 }
791 
792 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
793 					 int peer_type)
794 {
795 	/*
796 	 * We are to invalidate a service ticket in the hopes of
797 	 * getting a new, hopefully more valid, one.  But, we won't get
798 	 * it unless our AUTH ticket is good, so invalidate AUTH ticket
799 	 * as well, just in case.
800 	 */
801 	invalidate_ticket(ac, peer_type);
802 	invalidate_ticket(ac, CEPH_ENTITY_TYPE_AUTH);
803 }
804 
805 static int calc_signature(struct ceph_x_authorizer *au, struct ceph_msg *msg,
806 			  __le64 *psig)
807 {
808 	void *enc_buf = au->enc_buf;
809 	int ret;
810 
811 	if (!CEPH_HAVE_FEATURE(msg->con->peer_features, CEPHX_V2)) {
812 		struct {
813 			__le32 len;
814 			__le32 header_crc;
815 			__le32 front_crc;
816 			__le32 middle_crc;
817 			__le32 data_crc;
818 		} __packed *sigblock = enc_buf + ceph_x_encrypt_offset();
819 
820 		sigblock->len = cpu_to_le32(4*sizeof(u32));
821 		sigblock->header_crc = msg->hdr.crc;
822 		sigblock->front_crc = msg->footer.front_crc;
823 		sigblock->middle_crc = msg->footer.middle_crc;
824 		sigblock->data_crc =  msg->footer.data_crc;
825 
826 		ret = ceph_x_encrypt(&au->session_key, enc_buf,
827 				     CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock));
828 		if (ret < 0)
829 			return ret;
830 
831 		*psig = *(__le64 *)(enc_buf + sizeof(u32));
832 	} else {
833 		struct {
834 			__le32 header_crc;
835 			__le32 front_crc;
836 			__le32 front_len;
837 			__le32 middle_crc;
838 			__le32 middle_len;
839 			__le32 data_crc;
840 			__le32 data_len;
841 			__le32 seq_lower_word;
842 		} __packed *sigblock = enc_buf;
843 		struct {
844 			__le64 a, b, c, d;
845 		} __packed *penc = enc_buf;
846 		int ciphertext_len;
847 
848 		sigblock->header_crc = msg->hdr.crc;
849 		sigblock->front_crc = msg->footer.front_crc;
850 		sigblock->front_len = msg->hdr.front_len;
851 		sigblock->middle_crc = msg->footer.middle_crc;
852 		sigblock->middle_len = msg->hdr.middle_len;
853 		sigblock->data_crc =  msg->footer.data_crc;
854 		sigblock->data_len = msg->hdr.data_len;
855 		sigblock->seq_lower_word = *(__le32 *)&msg->hdr.seq;
856 
857 		/* no leading len, no ceph_x_encrypt_header */
858 		ret = ceph_crypt(&au->session_key, true, enc_buf,
859 				 CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock),
860 				 &ciphertext_len);
861 		if (ret)
862 			return ret;
863 
864 		*psig = penc->a ^ penc->b ^ penc->c ^ penc->d;
865 	}
866 
867 	return 0;
868 }
869 
870 static int ceph_x_sign_message(struct ceph_auth_handshake *auth,
871 			       struct ceph_msg *msg)
872 {
873 	__le64 sig;
874 	int ret;
875 
876 	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
877 		return 0;
878 
879 	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
880 			     msg, &sig);
881 	if (ret)
882 		return ret;
883 
884 	msg->footer.sig = sig;
885 	msg->footer.flags |= CEPH_MSG_FOOTER_SIGNED;
886 	return 0;
887 }
888 
889 static int ceph_x_check_message_signature(struct ceph_auth_handshake *auth,
890 					  struct ceph_msg *msg)
891 {
892 	__le64 sig_check;
893 	int ret;
894 
895 	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
896 		return 0;
897 
898 	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
899 			     msg, &sig_check);
900 	if (ret)
901 		return ret;
902 	if (sig_check == msg->footer.sig)
903 		return 0;
904 	if (msg->footer.flags & CEPH_MSG_FOOTER_SIGNED)
905 		dout("ceph_x_check_message_signature %p has signature %llx "
906 		     "expect %llx\n", msg, msg->footer.sig, sig_check);
907 	else
908 		dout("ceph_x_check_message_signature %p sender did not set "
909 		     "CEPH_MSG_FOOTER_SIGNED\n", msg);
910 	return -EBADMSG;
911 }
912 
913 static const struct ceph_auth_client_ops ceph_x_ops = {
914 	.name = "x",
915 	.is_authenticated = ceph_x_is_authenticated,
916 	.should_authenticate = ceph_x_should_authenticate,
917 	.build_request = ceph_x_build_request,
918 	.handle_reply = ceph_x_handle_reply,
919 	.create_authorizer = ceph_x_create_authorizer,
920 	.update_authorizer = ceph_x_update_authorizer,
921 	.add_authorizer_challenge = ceph_x_add_authorizer_challenge,
922 	.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
923 	.invalidate_authorizer = ceph_x_invalidate_authorizer,
924 	.reset =  ceph_x_reset,
925 	.destroy = ceph_x_destroy,
926 	.sign_message = ceph_x_sign_message,
927 	.check_message_signature = ceph_x_check_message_signature,
928 };
929 
930 
931 int ceph_x_init(struct ceph_auth_client *ac)
932 {
933 	struct ceph_x_info *xi;
934 	int ret;
935 
936 	dout("ceph_x_init %p\n", ac);
937 	ret = -ENOMEM;
938 	xi = kzalloc(sizeof(*xi), GFP_NOFS);
939 	if (!xi)
940 		goto out;
941 
942 	ret = -EINVAL;
943 	if (!ac->key) {
944 		pr_err("no secret set (for auth_x protocol)\n");
945 		goto out_nomem;
946 	}
947 
948 	ret = ceph_crypto_key_clone(&xi->secret, ac->key);
949 	if (ret < 0) {
950 		pr_err("cannot clone key: %d\n", ret);
951 		goto out_nomem;
952 	}
953 
954 	xi->starting = true;
955 	xi->ticket_handlers = RB_ROOT;
956 
957 	ac->protocol = CEPH_AUTH_CEPHX;
958 	ac->private = xi;
959 	ac->ops = &ceph_x_ops;
960 	return 0;
961 
962 out_nomem:
963 	kfree(xi);
964 out:
965 	return ret;
966 }
967