1
2#include <linux/ceph/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 <linux/ceph/decode.h>
10#include <linux/ceph/auth.h>
11
12#include "crypto.h"
13#include "auth_x.h"
14#include "auth_x_protocol.h"
15
16#define TEMP_TICKET_BUF_LEN	256
17
18static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
19
20static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
21{
22	struct ceph_x_info *xi = ac->private;
23	int need;
24
25	ceph_x_validate_tickets(ac, &need);
26	dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
27	     ac->want_keys, need, xi->have_keys);
28	return (ac->want_keys & xi->have_keys) == ac->want_keys;
29}
30
31static int ceph_x_should_authenticate(struct ceph_auth_client *ac)
32{
33	struct ceph_x_info *xi = ac->private;
34	int need;
35
36	ceph_x_validate_tickets(ac, &need);
37	dout("ceph_x_should_authenticate want=%d need=%d have=%d\n",
38	     ac->want_keys, need, xi->have_keys);
39	return need != 0;
40}
41
42static int ceph_x_encrypt_buflen(int ilen)
43{
44	return sizeof(struct ceph_x_encrypt_header) + ilen + 16 +
45		sizeof(u32);
46}
47
48static int ceph_x_encrypt(struct ceph_crypto_key *secret,
49			  void *ibuf, int ilen, void *obuf, size_t olen)
50{
51	struct ceph_x_encrypt_header head = {
52		.struct_v = 1,
53		.magic = cpu_to_le64(CEPHX_ENC_MAGIC)
54	};
55	size_t len = olen - sizeof(u32);
56	int ret;
57
58	ret = ceph_encrypt2(secret, obuf + sizeof(u32), &len,
59			    &head, sizeof(head), ibuf, ilen);
60	if (ret)
61		return ret;
62	ceph_encode_32(&obuf, len);
63	return len + sizeof(u32);
64}
65
66static int ceph_x_decrypt(struct ceph_crypto_key *secret,
67			  void **p, void *end, void *obuf, size_t olen)
68{
69	struct ceph_x_encrypt_header head;
70	size_t head_len = sizeof(head);
71	int len, ret;
72
73	len = ceph_decode_32(p);
74	if (*p + len > end)
75		return -EINVAL;
76
77	dout("ceph_x_decrypt len %d\n", len);
78	ret = ceph_decrypt2(secret, &head, &head_len, obuf, &olen,
79			    *p, len);
80	if (ret)
81		return ret;
82	if (head.struct_v != 1 || le64_to_cpu(head.magic) != CEPHX_ENC_MAGIC)
83		return -EPERM;
84	*p += len;
85	return olen;
86}
87
88/*
89 * get existing (or insert new) ticket handler
90 */
91static struct ceph_x_ticket_handler *
92get_ticket_handler(struct ceph_auth_client *ac, int service)
93{
94	struct ceph_x_ticket_handler *th;
95	struct ceph_x_info *xi = ac->private;
96	struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
97
98	while (*p) {
99		parent = *p;
100		th = rb_entry(parent, struct ceph_x_ticket_handler, node);
101		if (service < th->service)
102			p = &(*p)->rb_left;
103		else if (service > th->service)
104			p = &(*p)->rb_right;
105		else
106			return th;
107	}
108
109	/* add it */
110	th = kzalloc(sizeof(*th), GFP_NOFS);
111	if (!th)
112		return ERR_PTR(-ENOMEM);
113	th->service = service;
114	rb_link_node(&th->node, parent, p);
115	rb_insert_color(&th->node, &xi->ticket_handlers);
116	return th;
117}
118
119static void remove_ticket_handler(struct ceph_auth_client *ac,
120				  struct ceph_x_ticket_handler *th)
121{
122	struct ceph_x_info *xi = ac->private;
123
124	dout("remove_ticket_handler %p %d\n", th, th->service);
125	rb_erase(&th->node, &xi->ticket_handlers);
126	ceph_crypto_key_destroy(&th->session_key);
127	if (th->ticket_blob)
128		ceph_buffer_put(th->ticket_blob);
129	kfree(th);
130}
131
132static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
133				    struct ceph_crypto_key *secret,
134				    void *buf, void *end)
135{
136	struct ceph_x_info *xi = ac->private;
137	int num;
138	void *p = buf;
139	int ret;
140	char *dbuf;
141	char *ticket_buf;
142	u8 reply_struct_v;
143
144	dbuf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
145	if (!dbuf)
146		return -ENOMEM;
147
148	ret = -ENOMEM;
149	ticket_buf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
150	if (!ticket_buf)
151		goto out_dbuf;
152
153	ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
154	reply_struct_v = ceph_decode_8(&p);
155	if (reply_struct_v != 1)
156		goto bad;
157	num = ceph_decode_32(&p);
158	dout("%d tickets\n", num);
159	while (num--) {
160		int type;
161		u8 tkt_struct_v, blob_struct_v;
162		struct ceph_x_ticket_handler *th;
163		void *dp, *dend;
164		int dlen;
165		char is_enc;
166		struct timespec validity;
167		struct ceph_crypto_key old_key;
168		void *tp, *tpend;
169		struct ceph_timespec new_validity;
170		struct ceph_crypto_key new_session_key;
171		struct ceph_buffer *new_ticket_blob;
172		unsigned long new_expires, new_renew_after;
173		u64 new_secret_id;
174
175		ceph_decode_need(&p, end, sizeof(u32) + 1, bad);
176
177		type = ceph_decode_32(&p);
178		dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
179
180		tkt_struct_v = ceph_decode_8(&p);
181		if (tkt_struct_v != 1)
182			goto bad;
183
184		th = get_ticket_handler(ac, type);
185		if (IS_ERR(th)) {
186			ret = PTR_ERR(th);
187			goto out;
188		}
189
190		/* blob for me */
191		dlen = ceph_x_decrypt(secret, &p, end, dbuf,
192				      TEMP_TICKET_BUF_LEN);
193		if (dlen <= 0) {
194			ret = dlen;
195			goto out;
196		}
197		dout(" decrypted %d bytes\n", dlen);
198		dend = dbuf + dlen;
199		dp = dbuf;
200
201		tkt_struct_v = ceph_decode_8(&dp);
202		if (tkt_struct_v != 1)
203			goto bad;
204
205		memcpy(&old_key, &th->session_key, sizeof(old_key));
206		ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
207		if (ret)
208			goto out;
209
210		ceph_decode_copy(&dp, &new_validity, sizeof(new_validity));
211		ceph_decode_timespec(&validity, &new_validity);
212		new_expires = get_seconds() + validity.tv_sec;
213		new_renew_after = new_expires - (validity.tv_sec / 4);
214		dout(" expires=%lu renew_after=%lu\n", new_expires,
215		     new_renew_after);
216
217		/* ticket blob for service */
218		ceph_decode_8_safe(&p, end, is_enc, bad);
219		tp = ticket_buf;
220		if (is_enc) {
221			/* encrypted */
222			dout(" encrypted ticket\n");
223			dlen = ceph_x_decrypt(&old_key, &p, end, ticket_buf,
224					      TEMP_TICKET_BUF_LEN);
225			if (dlen < 0) {
226				ret = dlen;
227				goto out;
228			}
229			dlen = ceph_decode_32(&tp);
230		} else {
231			/* unencrypted */
232			ceph_decode_32_safe(&p, end, dlen, bad);
233			ceph_decode_need(&p, end, dlen, bad);
234			ceph_decode_copy(&p, ticket_buf, dlen);
235		}
236		tpend = tp + dlen;
237		dout(" ticket blob is %d bytes\n", dlen);
238		ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
239		blob_struct_v = ceph_decode_8(&tp);
240		new_secret_id = ceph_decode_64(&tp);
241		ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
242		if (ret)
243			goto out;
244
245		/* all is well, update our ticket */
246		ceph_crypto_key_destroy(&th->session_key);
247		if (th->ticket_blob)
248			ceph_buffer_put(th->ticket_blob);
249		th->session_key = new_session_key;
250		th->ticket_blob = new_ticket_blob;
251		th->validity = new_validity;
252		th->secret_id = new_secret_id;
253		th->expires = new_expires;
254		th->renew_after = new_renew_after;
255		dout(" got ticket service %d (%s) secret_id %lld len %d\n",
256		     type, ceph_entity_type_name(type), th->secret_id,
257		     (int)th->ticket_blob->vec.iov_len);
258		xi->have_keys |= th->service;
259	}
260
261	ret = 0;
262out:
263	kfree(ticket_buf);
264out_dbuf:
265	kfree(dbuf);
266	return ret;
267
268bad:
269	ret = -EINVAL;
270	goto out;
271}
272
273static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
274				   struct ceph_x_ticket_handler *th,
275				   struct ceph_x_authorizer *au)
276{
277	int maxlen;
278	struct ceph_x_authorize_a *msg_a;
279	struct ceph_x_authorize_b msg_b;
280	void *p, *end;
281	int ret;
282	int ticket_blob_len =
283		(th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
284
285	dout("build_authorizer for %s %p\n",
286	     ceph_entity_type_name(th->service), au);
287
288	maxlen = sizeof(*msg_a) + sizeof(msg_b) +
289		ceph_x_encrypt_buflen(ticket_blob_len);
290	dout("  need len %d\n", maxlen);
291	if (au->buf && au->buf->alloc_len < maxlen) {
292		ceph_buffer_put(au->buf);
293		au->buf = NULL;
294	}
295	if (!au->buf) {
296		au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
297		if (!au->buf)
298			return -ENOMEM;
299	}
300	au->service = th->service;
301	au->secret_id = th->secret_id;
302
303	msg_a = au->buf->vec.iov_base;
304	msg_a->struct_v = 1;
305	msg_a->global_id = cpu_to_le64(ac->global_id);
306	msg_a->service_id = cpu_to_le32(th->service);
307	msg_a->ticket_blob.struct_v = 1;
308	msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
309	msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
310	if (ticket_blob_len) {
311		memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
312		       th->ticket_blob->vec.iov_len);
313	}
314	dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
315	     le64_to_cpu(msg_a->ticket_blob.secret_id));
316
317	p = msg_a + 1;
318	p += ticket_blob_len;
319	end = au->buf->vec.iov_base + au->buf->vec.iov_len;
320
321	get_random_bytes(&au->nonce, sizeof(au->nonce));
322	msg_b.struct_v = 1;
323	msg_b.nonce = cpu_to_le64(au->nonce);
324	ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b),
325			     p, end - p);
326	if (ret < 0)
327		goto out_buf;
328	p += ret;
329	au->buf->vec.iov_len = p - au->buf->vec.iov_base;
330	dout(" built authorizer nonce %llx len %d\n", au->nonce,
331	     (int)au->buf->vec.iov_len);
332	BUG_ON(au->buf->vec.iov_len > maxlen);
333	return 0;
334
335out_buf:
336	ceph_buffer_put(au->buf);
337	au->buf = NULL;
338	return ret;
339}
340
341static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
342				void **p, void *end)
343{
344	ceph_decode_need(p, end, 1 + sizeof(u64), bad);
345	ceph_encode_8(p, 1);
346	ceph_encode_64(p, th->secret_id);
347	if (th->ticket_blob) {
348		const char *buf = th->ticket_blob->vec.iov_base;
349		u32 len = th->ticket_blob->vec.iov_len;
350
351		ceph_encode_32_safe(p, end, len, bad);
352		ceph_encode_copy_safe(p, end, buf, len, bad);
353	} else {
354		ceph_encode_32_safe(p, end, 0, bad);
355	}
356
357	return 0;
358bad:
359	return -ERANGE;
360}
361
362static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
363{
364	int want = ac->want_keys;
365	struct ceph_x_info *xi = ac->private;
366	int service;
367
368	*pneed = ac->want_keys & ~(xi->have_keys);
369
370	for (service = 1; service <= want; service <<= 1) {
371		struct ceph_x_ticket_handler *th;
372
373		if (!(ac->want_keys & service))
374			continue;
375
376		if (*pneed & service)
377			continue;
378
379		th = get_ticket_handler(ac, service);
380
381		if (IS_ERR(th)) {
382			*pneed |= service;
383			continue;
384		}
385
386		if (get_seconds() >= th->renew_after)
387			*pneed |= service;
388		if (get_seconds() >= th->expires)
389			xi->have_keys &= ~service;
390	}
391}
392
393
394static int ceph_x_build_request(struct ceph_auth_client *ac,
395				void *buf, void *end)
396{
397	struct ceph_x_info *xi = ac->private;
398	int need;
399	struct ceph_x_request_header *head = buf;
400	int ret;
401	struct ceph_x_ticket_handler *th =
402		get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
403
404	if (IS_ERR(th))
405		return PTR_ERR(th);
406
407	ceph_x_validate_tickets(ac, &need);
408
409	dout("build_request want %x have %x need %x\n",
410	     ac->want_keys, xi->have_keys, need);
411
412	if (need & CEPH_ENTITY_TYPE_AUTH) {
413		struct ceph_x_authenticate *auth = (void *)(head + 1);
414		void *p = auth + 1;
415		struct ceph_x_challenge_blob tmp;
416		char tmp_enc[40];
417		u64 *u;
418
419		if (p > end)
420			return -ERANGE;
421
422		dout(" get_auth_session_key\n");
423		head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
424
425		/* encrypt and hash */
426		get_random_bytes(&auth->client_challenge, sizeof(u64));
427		tmp.client_challenge = auth->client_challenge;
428		tmp.server_challenge = cpu_to_le64(xi->server_challenge);
429		ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp),
430				     tmp_enc, sizeof(tmp_enc));
431		if (ret < 0)
432			return ret;
433
434		auth->struct_v = 1;
435		auth->key = 0;
436		for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++)
437			auth->key ^= *(__le64 *)u;
438		dout(" server_challenge %llx client_challenge %llx key %llx\n",
439		     xi->server_challenge, le64_to_cpu(auth->client_challenge),
440		     le64_to_cpu(auth->key));
441
442		/* now encode the old ticket if exists */
443		ret = ceph_x_encode_ticket(th, &p, end);
444		if (ret < 0)
445			return ret;
446
447		return p - buf;
448	}
449
450	if (need) {
451		void *p = head + 1;
452		struct ceph_x_service_ticket_request *req;
453
454		if (p > end)
455			return -ERANGE;
456		head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
457
458		ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
459		if (ret)
460			return ret;
461		ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
462				 xi->auth_authorizer.buf->vec.iov_len);
463
464		req = p;
465		req->keys = cpu_to_le32(need);
466		p += sizeof(*req);
467		return p - buf;
468	}
469
470	return 0;
471}
472
473static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
474			       void *buf, void *end)
475{
476	struct ceph_x_info *xi = ac->private;
477	struct ceph_x_reply_header *head = buf;
478	struct ceph_x_ticket_handler *th;
479	int len = end - buf;
480	int op;
481	int ret;
482
483	if (result)
484		return result;  /* XXX hmm? */
485
486	if (xi->starting) {
487		/* it's a hello */
488		struct ceph_x_server_challenge *sc = buf;
489
490		if (len != sizeof(*sc))
491			return -EINVAL;
492		xi->server_challenge = le64_to_cpu(sc->server_challenge);
493		dout("handle_reply got server challenge %llx\n",
494		     xi->server_challenge);
495		xi->starting = false;
496		xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
497		return -EAGAIN;
498	}
499
500	op = le16_to_cpu(head->op);
501	result = le32_to_cpu(head->result);
502	dout("handle_reply op %d result %d\n", op, result);
503	switch (op) {
504	case CEPHX_GET_AUTH_SESSION_KEY:
505		/* verify auth key */
506		ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
507					       buf + sizeof(*head), end);
508		break;
509
510	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
511		th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
512		if (IS_ERR(th))
513			return PTR_ERR(th);
514		ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
515					       buf + sizeof(*head), end);
516		break;
517
518	default:
519		return -EINVAL;
520	}
521	if (ret)
522		return ret;
523	if (ac->want_keys == xi->have_keys)
524		return 0;
525	return -EAGAIN;
526}
527
528static int ceph_x_create_authorizer(
529	struct ceph_auth_client *ac, int peer_type,
530	struct ceph_auth_handshake *auth)
531{
532	struct ceph_x_authorizer *au;
533	struct ceph_x_ticket_handler *th;
534	int ret;
535
536	th = get_ticket_handler(ac, peer_type);
537	if (IS_ERR(th))
538		return PTR_ERR(th);
539
540	au = kzalloc(sizeof(*au), GFP_NOFS);
541	if (!au)
542		return -ENOMEM;
543
544	ret = ceph_x_build_authorizer(ac, th, au);
545	if (ret) {
546		kfree(au);
547		return ret;
548	}
549
550	auth->authorizer = (struct ceph_authorizer *) au;
551	auth->authorizer_buf = au->buf->vec.iov_base;
552	auth->authorizer_buf_len = au->buf->vec.iov_len;
553	auth->authorizer_reply_buf = au->reply_buf;
554	auth->authorizer_reply_buf_len = sizeof (au->reply_buf);
555
556	return 0;
557}
558
559static int ceph_x_update_authorizer(
560	struct ceph_auth_client *ac, int peer_type,
561	struct ceph_auth_handshake *auth)
562{
563	struct ceph_x_authorizer *au;
564	struct ceph_x_ticket_handler *th;
565
566	th = get_ticket_handler(ac, peer_type);
567	if (IS_ERR(th))
568		return PTR_ERR(th);
569
570	au = (struct ceph_x_authorizer *)auth->authorizer;
571	if (au->secret_id < th->secret_id) {
572		dout("ceph_x_update_authorizer service %u secret %llu < %llu\n",
573		     au->service, au->secret_id, th->secret_id);
574		return ceph_x_build_authorizer(ac, th, au);
575	}
576	return 0;
577}
578
579static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
580					  struct ceph_authorizer *a, size_t len)
581{
582	struct ceph_x_authorizer *au = (void *)a;
583	struct ceph_x_ticket_handler *th;
584	int ret = 0;
585	struct ceph_x_authorize_reply reply;
586	void *p = au->reply_buf;
587	void *end = p + sizeof(au->reply_buf);
588
589	th = get_ticket_handler(ac, au->service);
590	if (IS_ERR(th))
591		return PTR_ERR(th);
592	ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
593	if (ret < 0)
594		return ret;
595	if (ret != sizeof(reply))
596		return -EPERM;
597
598	if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one))
599		ret = -EPERM;
600	else
601		ret = 0;
602	dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
603	     au->nonce, le64_to_cpu(reply.nonce_plus_one), ret);
604	return ret;
605}
606
607static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
608				      struct ceph_authorizer *a)
609{
610	struct ceph_x_authorizer *au = (void *)a;
611
612	ceph_buffer_put(au->buf);
613	kfree(au);
614}
615
616
617static void ceph_x_reset(struct ceph_auth_client *ac)
618{
619	struct ceph_x_info *xi = ac->private;
620
621	dout("reset\n");
622	xi->starting = true;
623	xi->server_challenge = 0;
624}
625
626static void ceph_x_destroy(struct ceph_auth_client *ac)
627{
628	struct ceph_x_info *xi = ac->private;
629	struct rb_node *p;
630
631	dout("ceph_x_destroy %p\n", ac);
632	ceph_crypto_key_destroy(&xi->secret);
633
634	while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
635		struct ceph_x_ticket_handler *th =
636			rb_entry(p, struct ceph_x_ticket_handler, node);
637		remove_ticket_handler(ac, th);
638	}
639
640	if (xi->auth_authorizer.buf)
641		ceph_buffer_put(xi->auth_authorizer.buf);
642
643	kfree(ac->private);
644	ac->private = NULL;
645}
646
647static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
648				   int peer_type)
649{
650	struct ceph_x_ticket_handler *th;
651
652	th = get_ticket_handler(ac, peer_type);
653	if (!IS_ERR(th))
654		memset(&th->validity, 0, sizeof(th->validity));
655}
656
657
658static const struct ceph_auth_client_ops ceph_x_ops = {
659	.name = "x",
660	.is_authenticated = ceph_x_is_authenticated,
661	.should_authenticate = ceph_x_should_authenticate,
662	.build_request = ceph_x_build_request,
663	.handle_reply = ceph_x_handle_reply,
664	.create_authorizer = ceph_x_create_authorizer,
665	.update_authorizer = ceph_x_update_authorizer,
666	.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
667	.destroy_authorizer = ceph_x_destroy_authorizer,
668	.invalidate_authorizer = ceph_x_invalidate_authorizer,
669	.reset =  ceph_x_reset,
670	.destroy = ceph_x_destroy,
671};
672
673
674int ceph_x_init(struct ceph_auth_client *ac)
675{
676	struct ceph_x_info *xi;
677	int ret;
678
679	dout("ceph_x_init %p\n", ac);
680	ret = -ENOMEM;
681	xi = kzalloc(sizeof(*xi), GFP_NOFS);
682	if (!xi)
683		goto out;
684
685	ret = -EINVAL;
686	if (!ac->key) {
687		pr_err("no secret set (for auth_x protocol)\n");
688		goto out_nomem;
689	}
690
691	ret = ceph_crypto_key_clone(&xi->secret, ac->key);
692	if (ret < 0) {
693		pr_err("cannot clone key: %d\n", ret);
694		goto out_nomem;
695	}
696
697	xi->starting = true;
698	xi->ticket_handlers = RB_ROOT;
699
700	ac->protocol = CEPH_AUTH_CEPHX;
701	ac->private = xi;
702	ac->ops = &ceph_x_ops;
703	return 0;
704
705out_nomem:
706	kfree(xi);
707out:
708	return ret;
709}
710
711
712