xref: /linux/net/ceph/auth_x.c (revision 23f50b5ac331c8c27c421a7116618355508e8427)
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 missing;
26 	int need;  /* missing + need renewal */
27 
28 	ceph_x_validate_tickets(ac, &need);
29 	missing = ac->want_keys & ~xi->have_keys;
30 	WARN_ON((need & missing) != missing);
31 	dout("%s want 0x%x have 0x%x missing 0x%x -> %d\n", __func__,
32 	     ac->want_keys, xi->have_keys, missing, !missing);
33 	return !missing;
34 }
35 
36 static int ceph_x_should_authenticate(struct ceph_auth_client *ac)
37 {
38 	struct ceph_x_info *xi = ac->private;
39 	int need;
40 
41 	ceph_x_validate_tickets(ac, &need);
42 	dout("%s want 0x%x have 0x%x need 0x%x -> %d\n", __func__,
43 	     ac->want_keys, xi->have_keys, need, !!need);
44 	return !!need;
45 }
46 
47 static int ceph_x_encrypt_offset(void)
48 {
49 	return sizeof(u32) + sizeof(struct ceph_x_encrypt_header);
50 }
51 
52 static int ceph_x_encrypt_buflen(int ilen)
53 {
54 	return ceph_x_encrypt_offset() + ilen + 16;
55 }
56 
57 static int ceph_x_encrypt(struct ceph_crypto_key *secret, void *buf,
58 			  int buf_len, int plaintext_len)
59 {
60 	struct ceph_x_encrypt_header *hdr = buf + sizeof(u32);
61 	int ciphertext_len;
62 	int ret;
63 
64 	hdr->struct_v = 1;
65 	hdr->magic = cpu_to_le64(CEPHX_ENC_MAGIC);
66 
67 	ret = ceph_crypt(secret, true, buf + sizeof(u32), buf_len - sizeof(u32),
68 			 plaintext_len + sizeof(struct ceph_x_encrypt_header),
69 			 &ciphertext_len);
70 	if (ret)
71 		return ret;
72 
73 	ceph_encode_32(&buf, ciphertext_len);
74 	return sizeof(u32) + ciphertext_len;
75 }
76 
77 static int __ceph_x_decrypt(struct ceph_crypto_key *secret, void *p,
78 			    int ciphertext_len)
79 {
80 	struct ceph_x_encrypt_header *hdr = p;
81 	int plaintext_len;
82 	int ret;
83 
84 	ret = ceph_crypt(secret, false, p, ciphertext_len, ciphertext_len,
85 			 &plaintext_len);
86 	if (ret)
87 		return ret;
88 
89 	if (le64_to_cpu(hdr->magic) != CEPHX_ENC_MAGIC) {
90 		pr_err("%s bad magic\n", __func__);
91 		return -EINVAL;
92 	}
93 
94 	return plaintext_len - sizeof(*hdr);
95 }
96 
97 static int ceph_x_decrypt(struct ceph_crypto_key *secret, void **p, void *end)
98 {
99 	int ciphertext_len;
100 	int ret;
101 
102 	ceph_decode_32_safe(p, end, ciphertext_len, e_inval);
103 	ceph_decode_need(p, end, ciphertext_len, e_inval);
104 
105 	ret = __ceph_x_decrypt(secret, *p, ciphertext_len);
106 	if (ret < 0)
107 		return ret;
108 
109 	*p += ciphertext_len;
110 	return ret;
111 
112 e_inval:
113 	return -EINVAL;
114 }
115 
116 /*
117  * get existing (or insert new) ticket handler
118  */
119 static struct ceph_x_ticket_handler *
120 get_ticket_handler(struct ceph_auth_client *ac, int service)
121 {
122 	struct ceph_x_ticket_handler *th;
123 	struct ceph_x_info *xi = ac->private;
124 	struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
125 
126 	while (*p) {
127 		parent = *p;
128 		th = rb_entry(parent, struct ceph_x_ticket_handler, node);
129 		if (service < th->service)
130 			p = &(*p)->rb_left;
131 		else if (service > th->service)
132 			p = &(*p)->rb_right;
133 		else
134 			return th;
135 	}
136 
137 	/* add it */
138 	th = kzalloc(sizeof(*th), GFP_NOFS);
139 	if (!th)
140 		return ERR_PTR(-ENOMEM);
141 	th->service = service;
142 	rb_link_node(&th->node, parent, p);
143 	rb_insert_color(&th->node, &xi->ticket_handlers);
144 	return th;
145 }
146 
147 static void remove_ticket_handler(struct ceph_auth_client *ac,
148 				  struct ceph_x_ticket_handler *th)
149 {
150 	struct ceph_x_info *xi = ac->private;
151 
152 	dout("remove_ticket_handler %p %d\n", th, th->service);
153 	rb_erase(&th->node, &xi->ticket_handlers);
154 	ceph_crypto_key_destroy(&th->session_key);
155 	if (th->ticket_blob)
156 		ceph_buffer_put(th->ticket_blob);
157 	kfree(th);
158 }
159 
160 static int process_one_ticket(struct ceph_auth_client *ac,
161 			      struct ceph_crypto_key *secret,
162 			      void **p, void *end)
163 {
164 	struct ceph_x_info *xi = ac->private;
165 	int type;
166 	u8 tkt_struct_v, blob_struct_v;
167 	struct ceph_x_ticket_handler *th;
168 	void *dp, *dend;
169 	int dlen;
170 	char is_enc;
171 	struct timespec64 validity;
172 	void *tp, *tpend;
173 	void **ptp;
174 	struct ceph_crypto_key new_session_key = { 0 };
175 	struct ceph_buffer *new_ticket_blob;
176 	time64_t new_expires, new_renew_after;
177 	u64 new_secret_id;
178 	int ret;
179 
180 	ceph_decode_need(p, end, sizeof(u32) + 1, bad);
181 
182 	type = ceph_decode_32(p);
183 	dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
184 
185 	tkt_struct_v = ceph_decode_8(p);
186 	if (tkt_struct_v != 1)
187 		goto bad;
188 
189 	th = get_ticket_handler(ac, type);
190 	if (IS_ERR(th)) {
191 		ret = PTR_ERR(th);
192 		goto out;
193 	}
194 
195 	/* blob for me */
196 	dp = *p + ceph_x_encrypt_offset();
197 	ret = ceph_x_decrypt(secret, p, end);
198 	if (ret < 0)
199 		goto out;
200 	dout(" decrypted %d bytes\n", ret);
201 	dend = dp + ret;
202 
203 	ceph_decode_8_safe(&dp, dend, tkt_struct_v, bad);
204 	if (tkt_struct_v != 1)
205 		goto bad;
206 
207 	ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
208 	if (ret)
209 		goto out;
210 
211 	ceph_decode_need(&dp, dend, sizeof(struct ceph_timespec), bad);
212 	ceph_decode_timespec64(&validity, dp);
213 	dp += sizeof(struct ceph_timespec);
214 	new_expires = ktime_get_real_seconds() + validity.tv_sec;
215 	new_renew_after = new_expires - (validity.tv_sec / 4);
216 	dout(" expires=%llu renew_after=%llu\n", new_expires,
217 	     new_renew_after);
218 
219 	/* ticket blob for service */
220 	ceph_decode_8_safe(p, end, is_enc, bad);
221 	if (is_enc) {
222 		/* encrypted */
223 		tp = *p + ceph_x_encrypt_offset();
224 		ret = ceph_x_decrypt(&th->session_key, p, end);
225 		if (ret < 0)
226 			goto out;
227 		dout(" encrypted ticket, decrypted %d bytes\n", ret);
228 		ptp = &tp;
229 		tpend = tp + ret;
230 	} else {
231 		/* unencrypted */
232 		ptp = p;
233 		tpend = end;
234 	}
235 	ceph_decode_32_safe(ptp, tpend, dlen, bad);
236 	dout(" ticket blob is %d bytes\n", dlen);
237 	ceph_decode_need(ptp, tpend, 1 + sizeof(u64), bad);
238 	blob_struct_v = ceph_decode_8(ptp);
239 	if (blob_struct_v != 1)
240 		goto bad;
241 
242 	new_secret_id = ceph_decode_64(ptp);
243 	ret = ceph_decode_buffer(&new_ticket_blob, ptp, tpend);
244 	if (ret)
245 		goto out;
246 
247 	/* all is well, update our ticket */
248 	ceph_crypto_key_destroy(&th->session_key);
249 	if (th->ticket_blob)
250 		ceph_buffer_put(th->ticket_blob);
251 	th->session_key = new_session_key;
252 	th->ticket_blob = new_ticket_blob;
253 	th->secret_id = new_secret_id;
254 	th->expires = new_expires;
255 	th->renew_after = new_renew_after;
256 	th->have_key = true;
257 	dout(" got ticket service %d (%s) secret_id %lld len %d\n",
258 	     type, ceph_entity_type_name(type), th->secret_id,
259 	     (int)th->ticket_blob->vec.iov_len);
260 	xi->have_keys |= th->service;
261 	return 0;
262 
263 bad:
264 	ret = -EINVAL;
265 out:
266 	ceph_crypto_key_destroy(&new_session_key);
267 	return ret;
268 }
269 
270 static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
271 				    struct ceph_crypto_key *secret,
272 				    void **p, void *end)
273 {
274 	u8 reply_struct_v;
275 	u32 num;
276 	int ret;
277 
278 	ceph_decode_8_safe(p, end, reply_struct_v, bad);
279 	if (reply_struct_v != 1)
280 		return -EINVAL;
281 
282 	ceph_decode_32_safe(p, end, num, bad);
283 	dout("%d tickets\n", num);
284 
285 	while (num--) {
286 		ret = process_one_ticket(ac, secret, p, end);
287 		if (ret)
288 			return ret;
289 	}
290 
291 	return 0;
292 
293 bad:
294 	return -EINVAL;
295 }
296 
297 /*
298  * Encode and encrypt the second part (ceph_x_authorize_b) of the
299  * authorizer.  The first part (ceph_x_authorize_a) should already be
300  * encoded.
301  */
302 static int encrypt_authorizer(struct ceph_x_authorizer *au,
303 			      u64 *server_challenge)
304 {
305 	struct ceph_x_authorize_a *msg_a;
306 	struct ceph_x_authorize_b *msg_b;
307 	void *p, *end;
308 	int ret;
309 
310 	msg_a = au->buf->vec.iov_base;
311 	WARN_ON(msg_a->ticket_blob.secret_id != cpu_to_le64(au->secret_id));
312 	p = (void *)(msg_a + 1) + le32_to_cpu(msg_a->ticket_blob.blob_len);
313 	end = au->buf->vec.iov_base + au->buf->vec.iov_len;
314 
315 	msg_b = p + ceph_x_encrypt_offset();
316 	msg_b->struct_v = 2;
317 	msg_b->nonce = cpu_to_le64(au->nonce);
318 	if (server_challenge) {
319 		msg_b->have_challenge = 1;
320 		msg_b->server_challenge_plus_one =
321 		    cpu_to_le64(*server_challenge + 1);
322 	} else {
323 		msg_b->have_challenge = 0;
324 		msg_b->server_challenge_plus_one = 0;
325 	}
326 
327 	ret = ceph_x_encrypt(&au->session_key, p, end - p, sizeof(*msg_b));
328 	if (ret < 0)
329 		return ret;
330 
331 	p += ret;
332 	if (server_challenge) {
333 		WARN_ON(p != end);
334 	} else {
335 		WARN_ON(p > end);
336 		au->buf->vec.iov_len = p - au->buf->vec.iov_base;
337 	}
338 
339 	return 0;
340 }
341 
342 static void ceph_x_authorizer_cleanup(struct ceph_x_authorizer *au)
343 {
344 	ceph_crypto_key_destroy(&au->session_key);
345 	if (au->buf) {
346 		ceph_buffer_put(au->buf);
347 		au->buf = NULL;
348 	}
349 }
350 
351 static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
352 				   struct ceph_x_ticket_handler *th,
353 				   struct ceph_x_authorizer *au)
354 {
355 	int maxlen;
356 	struct ceph_x_authorize_a *msg_a;
357 	struct ceph_x_authorize_b *msg_b;
358 	int ret;
359 	int ticket_blob_len =
360 		(th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
361 
362 	dout("build_authorizer for %s %p\n",
363 	     ceph_entity_type_name(th->service), au);
364 
365 	ceph_crypto_key_destroy(&au->session_key);
366 	ret = ceph_crypto_key_clone(&au->session_key, &th->session_key);
367 	if (ret)
368 		goto out_au;
369 
370 	maxlen = sizeof(*msg_a) + ticket_blob_len +
371 		ceph_x_encrypt_buflen(sizeof(*msg_b));
372 	dout("  need len %d\n", maxlen);
373 	if (au->buf && au->buf->alloc_len < maxlen) {
374 		ceph_buffer_put(au->buf);
375 		au->buf = NULL;
376 	}
377 	if (!au->buf) {
378 		au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
379 		if (!au->buf) {
380 			ret = -ENOMEM;
381 			goto out_au;
382 		}
383 	}
384 	au->service = th->service;
385 	WARN_ON(!th->secret_id);
386 	au->secret_id = th->secret_id;
387 
388 	msg_a = au->buf->vec.iov_base;
389 	msg_a->struct_v = 1;
390 	msg_a->global_id = cpu_to_le64(ac->global_id);
391 	msg_a->service_id = cpu_to_le32(th->service);
392 	msg_a->ticket_blob.struct_v = 1;
393 	msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
394 	msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
395 	if (ticket_blob_len) {
396 		memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
397 		       th->ticket_blob->vec.iov_len);
398 	}
399 	dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
400 	     le64_to_cpu(msg_a->ticket_blob.secret_id));
401 
402 	get_random_bytes(&au->nonce, sizeof(au->nonce));
403 	ret = encrypt_authorizer(au, NULL);
404 	if (ret) {
405 		pr_err("failed to encrypt authorizer: %d", ret);
406 		goto out_au;
407 	}
408 
409 	dout(" built authorizer nonce %llx len %d\n", au->nonce,
410 	     (int)au->buf->vec.iov_len);
411 	return 0;
412 
413 out_au:
414 	ceph_x_authorizer_cleanup(au);
415 	return ret;
416 }
417 
418 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
419 				void **p, void *end)
420 {
421 	ceph_decode_need(p, end, 1 + sizeof(u64), bad);
422 	ceph_encode_8(p, 1);
423 	ceph_encode_64(p, th->secret_id);
424 	if (th->ticket_blob) {
425 		const char *buf = th->ticket_blob->vec.iov_base;
426 		u32 len = th->ticket_blob->vec.iov_len;
427 
428 		ceph_encode_32_safe(p, end, len, bad);
429 		ceph_encode_copy_safe(p, end, buf, len, bad);
430 	} else {
431 		ceph_encode_32_safe(p, end, 0, bad);
432 	}
433 
434 	return 0;
435 bad:
436 	return -ERANGE;
437 }
438 
439 static bool need_key(struct ceph_x_ticket_handler *th)
440 {
441 	if (!th->have_key)
442 		return true;
443 
444 	return ktime_get_real_seconds() >= th->renew_after;
445 }
446 
447 static bool have_key(struct ceph_x_ticket_handler *th)
448 {
449 	if (th->have_key && ktime_get_real_seconds() >= th->expires) {
450 		dout("ticket %d (%s) secret_id %llu expired\n", th->service,
451 		     ceph_entity_type_name(th->service), th->secret_id);
452 		th->have_key = false;
453 	}
454 
455 	return th->have_key;
456 }
457 
458 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
459 {
460 	int want = ac->want_keys;
461 	struct ceph_x_info *xi = ac->private;
462 	int service;
463 
464 	*pneed = ac->want_keys & ~(xi->have_keys);
465 
466 	for (service = 1; service <= want; service <<= 1) {
467 		struct ceph_x_ticket_handler *th;
468 
469 		if (!(ac->want_keys & service))
470 			continue;
471 
472 		if (*pneed & service)
473 			continue;
474 
475 		th = get_ticket_handler(ac, service);
476 		if (IS_ERR(th)) {
477 			*pneed |= service;
478 			continue;
479 		}
480 
481 		if (need_key(th))
482 			*pneed |= service;
483 		if (!have_key(th))
484 			xi->have_keys &= ~service;
485 	}
486 }
487 
488 static int ceph_x_build_request(struct ceph_auth_client *ac,
489 				void *buf, void *end)
490 {
491 	struct ceph_x_info *xi = ac->private;
492 	int need;
493 	struct ceph_x_request_header *head = buf;
494 	void *p;
495 	int ret;
496 	struct ceph_x_ticket_handler *th =
497 		get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
498 
499 	if (IS_ERR(th))
500 		return PTR_ERR(th);
501 
502 	ceph_x_validate_tickets(ac, &need);
503 	dout("%s want 0x%x have 0x%x need 0x%x\n", __func__, ac->want_keys,
504 	     xi->have_keys, need);
505 
506 	if (need & CEPH_ENTITY_TYPE_AUTH) {
507 		struct ceph_x_authenticate *auth = (void *)(head + 1);
508 		void *enc_buf = xi->auth_authorizer.enc_buf;
509 		struct ceph_x_challenge_blob *blob = enc_buf +
510 							ceph_x_encrypt_offset();
511 		u64 *u;
512 
513 		p = auth + 1;
514 		if (p > end)
515 			return -ERANGE;
516 
517 		dout(" get_auth_session_key\n");
518 		head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
519 
520 		/* encrypt and hash */
521 		get_random_bytes(&auth->client_challenge, sizeof(u64));
522 		blob->client_challenge = auth->client_challenge;
523 		blob->server_challenge = cpu_to_le64(xi->server_challenge);
524 		ret = ceph_x_encrypt(&xi->secret, enc_buf, CEPHX_AU_ENC_BUF_LEN,
525 				     sizeof(*blob));
526 		if (ret < 0)
527 			return ret;
528 
529 		auth->struct_v = 2;  /* nautilus+ */
530 		auth->key = 0;
531 		for (u = (u64 *)enc_buf; u + 1 <= (u64 *)(enc_buf + ret); u++)
532 			auth->key ^= *(__le64 *)u;
533 		dout(" server_challenge %llx client_challenge %llx key %llx\n",
534 		     xi->server_challenge, le64_to_cpu(auth->client_challenge),
535 		     le64_to_cpu(auth->key));
536 
537 		/* now encode the old ticket if exists */
538 		ret = ceph_x_encode_ticket(th, &p, end);
539 		if (ret < 0)
540 			return ret;
541 
542 		/* nautilus+: request service tickets at the same time */
543 		need = ac->want_keys & ~CEPH_ENTITY_TYPE_AUTH;
544 		WARN_ON(!need);
545 		ceph_encode_32_safe(&p, end, need, e_range);
546 		return p - buf;
547 	}
548 
549 	if (need) {
550 		dout(" get_principal_session_key\n");
551 		ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
552 		if (ret)
553 			return ret;
554 
555 		p = buf;
556 		ceph_encode_16_safe(&p, end, CEPHX_GET_PRINCIPAL_SESSION_KEY,
557 				    e_range);
558 		ceph_encode_copy_safe(&p, end,
559 			xi->auth_authorizer.buf->vec.iov_base,
560 			xi->auth_authorizer.buf->vec.iov_len, e_range);
561 		ceph_encode_8_safe(&p, end, 1, e_range);
562 		ceph_encode_32_safe(&p, end, need, e_range);
563 		return p - buf;
564 	}
565 
566 	return 0;
567 
568 e_range:
569 	return -ERANGE;
570 }
571 
572 static int decode_con_secret(void **p, void *end, u8 *con_secret,
573 			     int *con_secret_len)
574 {
575 	int len;
576 
577 	ceph_decode_32_safe(p, end, len, bad);
578 	ceph_decode_need(p, end, len, bad);
579 
580 	dout("%s len %d\n", __func__, len);
581 	if (con_secret) {
582 		if (len > CEPH_MAX_CON_SECRET_LEN) {
583 			pr_err("connection secret too big %d\n", len);
584 			goto bad_memzero;
585 		}
586 		memcpy(con_secret, *p, len);
587 		*con_secret_len = len;
588 	}
589 	memzero_explicit(*p, len);
590 	*p += len;
591 	return 0;
592 
593 bad_memzero:
594 	memzero_explicit(*p, len);
595 bad:
596 	pr_err("failed to decode connection secret\n");
597 	return -EINVAL;
598 }
599 
600 static int handle_auth_session_key(struct ceph_auth_client *ac,
601 				   void **p, void *end,
602 				   u8 *session_key, int *session_key_len,
603 				   u8 *con_secret, int *con_secret_len)
604 {
605 	struct ceph_x_info *xi = ac->private;
606 	struct ceph_x_ticket_handler *th;
607 	void *dp, *dend;
608 	int len;
609 	int ret;
610 
611 	/* AUTH ticket */
612 	ret = ceph_x_proc_ticket_reply(ac, &xi->secret, p, end);
613 	if (ret)
614 		return ret;
615 
616 	if (*p == end) {
617 		/* pre-nautilus (or didn't request service tickets!) */
618 		WARN_ON(session_key || con_secret);
619 		return 0;
620 	}
621 
622 	th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
623 	if (IS_ERR(th))
624 		return PTR_ERR(th);
625 
626 	if (session_key) {
627 		memcpy(session_key, th->session_key.key, th->session_key.len);
628 		*session_key_len = th->session_key.len;
629 	}
630 
631 	/* connection secret */
632 	ceph_decode_32_safe(p, end, len, e_inval);
633 	dout("%s connection secret blob len %d\n", __func__, len);
634 	if (len > 0) {
635 		dp = *p + ceph_x_encrypt_offset();
636 		ret = ceph_x_decrypt(&th->session_key, p, *p + len);
637 		if (ret < 0)
638 			return ret;
639 
640 		dout("%s decrypted %d bytes\n", __func__, ret);
641 		dend = dp + ret;
642 
643 		ret = decode_con_secret(&dp, dend, con_secret, con_secret_len);
644 		if (ret)
645 			return ret;
646 	}
647 
648 	/* service tickets */
649 	ceph_decode_32_safe(p, end, len, e_inval);
650 	dout("%s service tickets blob len %d\n", __func__, len);
651 	if (len > 0) {
652 		ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
653 					       p, *p + len);
654 		if (ret)
655 			return ret;
656 	}
657 
658 	return 0;
659 
660 e_inval:
661 	return -EINVAL;
662 }
663 
664 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
665 			       void *buf, void *end,
666 			       u8 *session_key, int *session_key_len,
667 			       u8 *con_secret, int *con_secret_len)
668 {
669 	struct ceph_x_info *xi = ac->private;
670 	struct ceph_x_ticket_handler *th;
671 	int len = end - buf;
672 	void *p;
673 	int op;
674 	int ret;
675 
676 	if (result)
677 		return result;  /* XXX hmm? */
678 
679 	if (xi->starting) {
680 		/* it's a hello */
681 		struct ceph_x_server_challenge *sc = buf;
682 
683 		if (len != sizeof(*sc))
684 			return -EINVAL;
685 		xi->server_challenge = le64_to_cpu(sc->server_challenge);
686 		dout("handle_reply got server challenge %llx\n",
687 		     xi->server_challenge);
688 		xi->starting = false;
689 		xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
690 		return -EAGAIN;
691 	}
692 
693 	p = buf;
694 	ceph_decode_16_safe(&p, end, op, e_inval);
695 	ceph_decode_32_safe(&p, end, result, e_inval);
696 	dout("handle_reply op %d result %d\n", op, result);
697 	switch (op) {
698 	case CEPHX_GET_AUTH_SESSION_KEY:
699 		/* AUTH ticket + [connection secret] + service tickets */
700 		ret = handle_auth_session_key(ac, &p, end, session_key,
701 					      session_key_len, con_secret,
702 					      con_secret_len);
703 		break;
704 
705 	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
706 		th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
707 		if (IS_ERR(th))
708 			return PTR_ERR(th);
709 
710 		/* service tickets */
711 		ret = ceph_x_proc_ticket_reply(ac, &th->session_key, &p, end);
712 		break;
713 
714 	default:
715 		return -EINVAL;
716 	}
717 	if (ret)
718 		return ret;
719 	if (ac->want_keys == xi->have_keys)
720 		return 0;
721 	return -EAGAIN;
722 
723 e_inval:
724 	return -EINVAL;
725 }
726 
727 static void ceph_x_destroy_authorizer(struct ceph_authorizer *a)
728 {
729 	struct ceph_x_authorizer *au = (void *)a;
730 
731 	ceph_x_authorizer_cleanup(au);
732 	kfree(au);
733 }
734 
735 static int ceph_x_create_authorizer(
736 	struct ceph_auth_client *ac, int peer_type,
737 	struct ceph_auth_handshake *auth)
738 {
739 	struct ceph_x_authorizer *au;
740 	struct ceph_x_ticket_handler *th;
741 	int ret;
742 
743 	th = get_ticket_handler(ac, peer_type);
744 	if (IS_ERR(th))
745 		return PTR_ERR(th);
746 
747 	au = kzalloc(sizeof(*au), GFP_NOFS);
748 	if (!au)
749 		return -ENOMEM;
750 
751 	au->base.destroy = ceph_x_destroy_authorizer;
752 
753 	ret = ceph_x_build_authorizer(ac, th, au);
754 	if (ret) {
755 		kfree(au);
756 		return ret;
757 	}
758 
759 	auth->authorizer = (struct ceph_authorizer *) au;
760 	auth->authorizer_buf = au->buf->vec.iov_base;
761 	auth->authorizer_buf_len = au->buf->vec.iov_len;
762 	auth->authorizer_reply_buf = au->enc_buf;
763 	auth->authorizer_reply_buf_len = CEPHX_AU_ENC_BUF_LEN;
764 	auth->sign_message = ac->ops->sign_message;
765 	auth->check_message_signature = ac->ops->check_message_signature;
766 
767 	return 0;
768 }
769 
770 static int ceph_x_update_authorizer(
771 	struct ceph_auth_client *ac, int peer_type,
772 	struct ceph_auth_handshake *auth)
773 {
774 	struct ceph_x_authorizer *au;
775 	struct ceph_x_ticket_handler *th;
776 
777 	th = get_ticket_handler(ac, peer_type);
778 	if (IS_ERR(th))
779 		return PTR_ERR(th);
780 
781 	au = (struct ceph_x_authorizer *)auth->authorizer;
782 	if (au->secret_id < th->secret_id) {
783 		dout("ceph_x_update_authorizer service %u secret %llu < %llu\n",
784 		     au->service, au->secret_id, th->secret_id);
785 		return ceph_x_build_authorizer(ac, th, au);
786 	}
787 	return 0;
788 }
789 
790 /*
791  * CephXAuthorizeChallenge
792  */
793 static int decrypt_authorizer_challenge(struct ceph_crypto_key *secret,
794 					void *challenge, int challenge_len,
795 					u64 *server_challenge)
796 {
797 	void *dp, *dend;
798 	int ret;
799 
800 	/* no leading len */
801 	ret = __ceph_x_decrypt(secret, challenge, challenge_len);
802 	if (ret < 0)
803 		return ret;
804 
805 	dout("%s decrypted %d bytes\n", __func__, ret);
806 	dp = challenge + sizeof(struct ceph_x_encrypt_header);
807 	dend = dp + ret;
808 
809 	ceph_decode_skip_8(&dp, dend, e_inval);  /* struct_v */
810 	ceph_decode_64_safe(&dp, dend, *server_challenge, e_inval);
811 	dout("%s server_challenge %llu\n", __func__, *server_challenge);
812 	return 0;
813 
814 e_inval:
815 	return -EINVAL;
816 }
817 
818 static int ceph_x_add_authorizer_challenge(struct ceph_auth_client *ac,
819 					   struct ceph_authorizer *a,
820 					   void *challenge, int challenge_len)
821 {
822 	struct ceph_x_authorizer *au = (void *)a;
823 	u64 server_challenge;
824 	int ret;
825 
826 	ret = decrypt_authorizer_challenge(&au->session_key, challenge,
827 					   challenge_len, &server_challenge);
828 	if (ret) {
829 		pr_err("failed to decrypt authorize challenge: %d", ret);
830 		return ret;
831 	}
832 
833 	ret = encrypt_authorizer(au, &server_challenge);
834 	if (ret) {
835 		pr_err("failed to encrypt authorizer w/ challenge: %d", ret);
836 		return ret;
837 	}
838 
839 	return 0;
840 }
841 
842 /*
843  * CephXAuthorizeReply
844  */
845 static int decrypt_authorizer_reply(struct ceph_crypto_key *secret,
846 				    void **p, void *end, u64 *nonce_plus_one,
847 				    u8 *con_secret, int *con_secret_len)
848 {
849 	void *dp, *dend;
850 	u8 struct_v;
851 	int ret;
852 
853 	dp = *p + ceph_x_encrypt_offset();
854 	ret = ceph_x_decrypt(secret, p, end);
855 	if (ret < 0)
856 		return ret;
857 
858 	dout("%s decrypted %d bytes\n", __func__, ret);
859 	dend = dp + ret;
860 
861 	ceph_decode_8_safe(&dp, dend, struct_v, e_inval);
862 	ceph_decode_64_safe(&dp, dend, *nonce_plus_one, e_inval);
863 	dout("%s nonce_plus_one %llu\n", __func__, *nonce_plus_one);
864 	if (struct_v >= 2) {
865 		ret = decode_con_secret(&dp, dend, con_secret, con_secret_len);
866 		if (ret)
867 			return ret;
868 	}
869 
870 	return 0;
871 
872 e_inval:
873 	return -EINVAL;
874 }
875 
876 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
877 					  struct ceph_authorizer *a,
878 					  void *reply, int reply_len,
879 					  u8 *session_key, int *session_key_len,
880 					  u8 *con_secret, int *con_secret_len)
881 {
882 	struct ceph_x_authorizer *au = (void *)a;
883 	u64 nonce_plus_one;
884 	int ret;
885 
886 	if (session_key) {
887 		memcpy(session_key, au->session_key.key, au->session_key.len);
888 		*session_key_len = au->session_key.len;
889 	}
890 
891 	ret = decrypt_authorizer_reply(&au->session_key, &reply,
892 				       reply + reply_len, &nonce_plus_one,
893 				       con_secret, con_secret_len);
894 	if (ret)
895 		return ret;
896 
897 	if (nonce_plus_one != au->nonce + 1) {
898 		pr_err("failed to authenticate server\n");
899 		return -EPERM;
900 	}
901 
902 	return 0;
903 }
904 
905 static void ceph_x_reset(struct ceph_auth_client *ac)
906 {
907 	struct ceph_x_info *xi = ac->private;
908 
909 	dout("reset\n");
910 	xi->starting = true;
911 	xi->server_challenge = 0;
912 }
913 
914 static void ceph_x_destroy(struct ceph_auth_client *ac)
915 {
916 	struct ceph_x_info *xi = ac->private;
917 	struct rb_node *p;
918 
919 	dout("ceph_x_destroy %p\n", ac);
920 	ceph_crypto_key_destroy(&xi->secret);
921 
922 	while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
923 		struct ceph_x_ticket_handler *th =
924 			rb_entry(p, struct ceph_x_ticket_handler, node);
925 		remove_ticket_handler(ac, th);
926 	}
927 
928 	ceph_x_authorizer_cleanup(&xi->auth_authorizer);
929 
930 	kfree(ac->private);
931 	ac->private = NULL;
932 }
933 
934 static void invalidate_ticket(struct ceph_auth_client *ac, int peer_type)
935 {
936 	struct ceph_x_ticket_handler *th;
937 
938 	th = get_ticket_handler(ac, peer_type);
939 	if (IS_ERR(th))
940 		return;
941 
942 	if (th->have_key) {
943 		dout("ticket %d (%s) secret_id %llu invalidated\n",
944 		     th->service, ceph_entity_type_name(th->service),
945 		     th->secret_id);
946 		th->have_key = false;
947 	}
948 }
949 
950 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
951 					 int peer_type)
952 {
953 	/*
954 	 * We are to invalidate a service ticket in the hopes of
955 	 * getting a new, hopefully more valid, one.  But, we won't get
956 	 * it unless our AUTH ticket is good, so invalidate AUTH ticket
957 	 * as well, just in case.
958 	 */
959 	invalidate_ticket(ac, peer_type);
960 	invalidate_ticket(ac, CEPH_ENTITY_TYPE_AUTH);
961 }
962 
963 static int calc_signature(struct ceph_x_authorizer *au, struct ceph_msg *msg,
964 			  __le64 *psig)
965 {
966 	void *enc_buf = au->enc_buf;
967 	int ret;
968 
969 	if (!CEPH_HAVE_FEATURE(msg->con->peer_features, CEPHX_V2)) {
970 		struct {
971 			__le32 len;
972 			__le32 header_crc;
973 			__le32 front_crc;
974 			__le32 middle_crc;
975 			__le32 data_crc;
976 		} __packed *sigblock = enc_buf + ceph_x_encrypt_offset();
977 
978 		sigblock->len = cpu_to_le32(4*sizeof(u32));
979 		sigblock->header_crc = msg->hdr.crc;
980 		sigblock->front_crc = msg->footer.front_crc;
981 		sigblock->middle_crc = msg->footer.middle_crc;
982 		sigblock->data_crc =  msg->footer.data_crc;
983 
984 		ret = ceph_x_encrypt(&au->session_key, enc_buf,
985 				     CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock));
986 		if (ret < 0)
987 			return ret;
988 
989 		*psig = *(__le64 *)(enc_buf + sizeof(u32));
990 	} else {
991 		struct {
992 			__le32 header_crc;
993 			__le32 front_crc;
994 			__le32 front_len;
995 			__le32 middle_crc;
996 			__le32 middle_len;
997 			__le32 data_crc;
998 			__le32 data_len;
999 			__le32 seq_lower_word;
1000 		} __packed *sigblock = enc_buf;
1001 		struct {
1002 			__le64 a, b, c, d;
1003 		} __packed *penc = enc_buf;
1004 		int ciphertext_len;
1005 
1006 		sigblock->header_crc = msg->hdr.crc;
1007 		sigblock->front_crc = msg->footer.front_crc;
1008 		sigblock->front_len = msg->hdr.front_len;
1009 		sigblock->middle_crc = msg->footer.middle_crc;
1010 		sigblock->middle_len = msg->hdr.middle_len;
1011 		sigblock->data_crc =  msg->footer.data_crc;
1012 		sigblock->data_len = msg->hdr.data_len;
1013 		sigblock->seq_lower_word = *(__le32 *)&msg->hdr.seq;
1014 
1015 		/* no leading len, no ceph_x_encrypt_header */
1016 		ret = ceph_crypt(&au->session_key, true, enc_buf,
1017 				 CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock),
1018 				 &ciphertext_len);
1019 		if (ret)
1020 			return ret;
1021 
1022 		*psig = penc->a ^ penc->b ^ penc->c ^ penc->d;
1023 	}
1024 
1025 	return 0;
1026 }
1027 
1028 static int ceph_x_sign_message(struct ceph_auth_handshake *auth,
1029 			       struct ceph_msg *msg)
1030 {
1031 	__le64 sig;
1032 	int ret;
1033 
1034 	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
1035 		return 0;
1036 
1037 	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
1038 			     msg, &sig);
1039 	if (ret)
1040 		return ret;
1041 
1042 	msg->footer.sig = sig;
1043 	msg->footer.flags |= CEPH_MSG_FOOTER_SIGNED;
1044 	return 0;
1045 }
1046 
1047 static int ceph_x_check_message_signature(struct ceph_auth_handshake *auth,
1048 					  struct ceph_msg *msg)
1049 {
1050 	__le64 sig_check;
1051 	int ret;
1052 
1053 	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
1054 		return 0;
1055 
1056 	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
1057 			     msg, &sig_check);
1058 	if (ret)
1059 		return ret;
1060 	if (sig_check == msg->footer.sig)
1061 		return 0;
1062 	if (msg->footer.flags & CEPH_MSG_FOOTER_SIGNED)
1063 		dout("ceph_x_check_message_signature %p has signature %llx "
1064 		     "expect %llx\n", msg, msg->footer.sig, sig_check);
1065 	else
1066 		dout("ceph_x_check_message_signature %p sender did not set "
1067 		     "CEPH_MSG_FOOTER_SIGNED\n", msg);
1068 	return -EBADMSG;
1069 }
1070 
1071 static const struct ceph_auth_client_ops ceph_x_ops = {
1072 	.is_authenticated = ceph_x_is_authenticated,
1073 	.should_authenticate = ceph_x_should_authenticate,
1074 	.build_request = ceph_x_build_request,
1075 	.handle_reply = ceph_x_handle_reply,
1076 	.create_authorizer = ceph_x_create_authorizer,
1077 	.update_authorizer = ceph_x_update_authorizer,
1078 	.add_authorizer_challenge = ceph_x_add_authorizer_challenge,
1079 	.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
1080 	.invalidate_authorizer = ceph_x_invalidate_authorizer,
1081 	.reset =  ceph_x_reset,
1082 	.destroy = ceph_x_destroy,
1083 	.sign_message = ceph_x_sign_message,
1084 	.check_message_signature = ceph_x_check_message_signature,
1085 };
1086 
1087 
1088 int ceph_x_init(struct ceph_auth_client *ac)
1089 {
1090 	struct ceph_x_info *xi;
1091 	int ret;
1092 
1093 	dout("ceph_x_init %p\n", ac);
1094 	ret = -ENOMEM;
1095 	xi = kzalloc(sizeof(*xi), GFP_NOFS);
1096 	if (!xi)
1097 		goto out;
1098 
1099 	ret = -EINVAL;
1100 	if (!ac->key) {
1101 		pr_err("no secret set (for auth_x protocol)\n");
1102 		goto out_nomem;
1103 	}
1104 
1105 	ret = ceph_crypto_key_clone(&xi->secret, ac->key);
1106 	if (ret < 0) {
1107 		pr_err("cannot clone key: %d\n", ret);
1108 		goto out_nomem;
1109 	}
1110 
1111 	xi->starting = true;
1112 	xi->ticket_handlers = RB_ROOT;
1113 
1114 	ac->protocol = CEPH_AUTH_CEPHX;
1115 	ac->private = xi;
1116 	ac->ops = &ceph_x_ops;
1117 	return 0;
1118 
1119 out_nomem:
1120 	kfree(xi);
1121 out:
1122 	return ret;
1123 }
1124