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
  20static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
  21
  22static 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
  36static 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
  47static int ceph_x_encrypt_offset(void)
  48{
  49	return sizeof(u32) + sizeof(struct ceph_x_encrypt_header);
  50}
  51
  52static int ceph_x_encrypt_buflen(int ilen)
  53{
  54	return ceph_x_encrypt_offset() + ilen + 16;
  55}
  56
  57static 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
  77static 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
  97static 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
 112e_inval:
 113	return -EINVAL;
 114}
 115
 116/*
 117 * get existing (or insert new) ticket handler
 118 */
 119static struct ceph_x_ticket_handler *
 120get_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
 147static 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
 160static 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
 263bad:
 264	ret = -EINVAL;
 265out:
 266	ceph_crypto_key_destroy(&new_session_key);
 267	return ret;
 268}
 269
 270static 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
 293bad:
 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 */
 302static 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
 342static 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
 351static 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
 413out_au:
 414	ceph_x_authorizer_cleanup(au);
 415	return ret;
 416}
 417
 418static 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;
 435bad:
 436	return -ERANGE;
 437}
 438
 439static 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
 447static 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
 458static 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
 488static 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 = 3;  /* 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
 568e_range:
 569	return -ERANGE;
 570}
 571
 572static 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
 593bad_memzero:
 594	memzero_explicit(*p, len);
 595bad:
 596	pr_err("failed to decode connection secret\n");
 597	return -EINVAL;
 598}
 599
 600static int handle_auth_session_key(struct ceph_auth_client *ac, u64 global_id,
 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	ceph_auth_set_global_id(ac, global_id);
 617	if (*p == end) {
 618		/* pre-nautilus (or didn't request service tickets!) */
 619		WARN_ON(session_key || con_secret);
 620		return 0;
 621	}
 622
 623	th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
 624	if (IS_ERR(th))
 625		return PTR_ERR(th);
 626
 627	if (session_key) {
 628		memcpy(session_key, th->session_key.key, th->session_key.len);
 629		*session_key_len = th->session_key.len;
 630	}
 631
 632	/* connection secret */
 633	ceph_decode_32_safe(p, end, len, e_inval);
 634	dout("%s connection secret blob len %d\n", __func__, len);
 635	if (len > 0) {
 636		dp = *p + ceph_x_encrypt_offset();
 637		ret = ceph_x_decrypt(&th->session_key, p, *p + len);
 638		if (ret < 0)
 639			return ret;
 640
 641		dout("%s decrypted %d bytes\n", __func__, ret);
 642		dend = dp + ret;
 643
 644		ret = decode_con_secret(&dp, dend, con_secret, con_secret_len);
 645		if (ret)
 646			return ret;
 647	}
 648
 649	/* service tickets */
 650	ceph_decode_32_safe(p, end, len, e_inval);
 651	dout("%s service tickets blob len %d\n", __func__, len);
 652	if (len > 0) {
 653		ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
 654					       p, *p + len);
 655		if (ret)
 656			return ret;
 657	}
 658
 659	return 0;
 660
 661e_inval:
 662	return -EINVAL;
 663}
 664
 665static int ceph_x_handle_reply(struct ceph_auth_client *ac, u64 global_id,
 666			       void *buf, void *end,
 667			       u8 *session_key, int *session_key_len,
 668			       u8 *con_secret, int *con_secret_len)
 669{
 670	struct ceph_x_info *xi = ac->private;
 671	struct ceph_x_ticket_handler *th;
 672	int len = end - buf;
 673	int result;
 674	void *p;
 675	int op;
 676	int ret;
 677
 678	if (xi->starting) {
 679		/* it's a hello */
 680		struct ceph_x_server_challenge *sc = buf;
 681
 682		if (len != sizeof(*sc))
 683			return -EINVAL;
 684		xi->server_challenge = le64_to_cpu(sc->server_challenge);
 685		dout("handle_reply got server challenge %llx\n",
 686		     xi->server_challenge);
 687		xi->starting = false;
 688		xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
 689		return -EAGAIN;
 690	}
 691
 692	p = buf;
 693	ceph_decode_16_safe(&p, end, op, e_inval);
 694	ceph_decode_32_safe(&p, end, result, e_inval);
 695	dout("handle_reply op %d result %d\n", op, result);
 696	switch (op) {
 697	case CEPHX_GET_AUTH_SESSION_KEY:
 698		/* AUTH ticket + [connection secret] + service tickets */
 699		ret = handle_auth_session_key(ac, global_id, &p, end,
 700					      session_key, session_key_len,
 701					      con_secret, con_secret_len);
 702		break;
 703
 704	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
 705		th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
 706		if (IS_ERR(th))
 707			return PTR_ERR(th);
 708
 709		/* service tickets */
 710		ret = ceph_x_proc_ticket_reply(ac, &th->session_key, &p, end);
 711		break;
 712
 713	default:
 714		return -EINVAL;
 715	}
 716	if (ret)
 717		return ret;
 718	if (ac->want_keys == xi->have_keys)
 719		return 0;
 720	return -EAGAIN;
 721
 722e_inval:
 723	return -EINVAL;
 724}
 725
 726static void ceph_x_destroy_authorizer(struct ceph_authorizer *a)
 727{
 728	struct ceph_x_authorizer *au = (void *)a;
 729
 730	ceph_x_authorizer_cleanup(au);
 731	kfree(au);
 732}
 733
 734static int ceph_x_create_authorizer(
 735	struct ceph_auth_client *ac, int peer_type,
 736	struct ceph_auth_handshake *auth)
 737{
 738	struct ceph_x_authorizer *au;
 739	struct ceph_x_ticket_handler *th;
 740	int ret;
 741
 742	th = get_ticket_handler(ac, peer_type);
 743	if (IS_ERR(th))
 744		return PTR_ERR(th);
 745
 746	au = kzalloc(sizeof(*au), GFP_NOFS);
 747	if (!au)
 748		return -ENOMEM;
 749
 750	au->base.destroy = ceph_x_destroy_authorizer;
 751
 752	ret = ceph_x_build_authorizer(ac, th, au);
 753	if (ret) {
 754		kfree(au);
 755		return ret;
 756	}
 757
 758	auth->authorizer = (struct ceph_authorizer *) au;
 759	auth->authorizer_buf = au->buf->vec.iov_base;
 760	auth->authorizer_buf_len = au->buf->vec.iov_len;
 761	auth->authorizer_reply_buf = au->enc_buf;
 762	auth->authorizer_reply_buf_len = CEPHX_AU_ENC_BUF_LEN;
 763	auth->sign_message = ac->ops->sign_message;
 764	auth->check_message_signature = ac->ops->check_message_signature;
 765
 766	return 0;
 767}
 768
 769static int ceph_x_update_authorizer(
 770	struct ceph_auth_client *ac, int peer_type,
 771	struct ceph_auth_handshake *auth)
 772{
 773	struct ceph_x_authorizer *au;
 774	struct ceph_x_ticket_handler *th;
 775
 776	th = get_ticket_handler(ac, peer_type);
 777	if (IS_ERR(th))
 778		return PTR_ERR(th);
 779
 780	au = (struct ceph_x_authorizer *)auth->authorizer;
 781	if (au->secret_id < th->secret_id) {
 782		dout("ceph_x_update_authorizer service %u secret %llu < %llu\n",
 783		     au->service, au->secret_id, th->secret_id);
 784		return ceph_x_build_authorizer(ac, th, au);
 785	}
 786	return 0;
 787}
 788
 789/*
 790 * CephXAuthorizeChallenge
 791 */
 792static int decrypt_authorizer_challenge(struct ceph_crypto_key *secret,
 793					void *challenge, int challenge_len,
 794					u64 *server_challenge)
 795{
 796	void *dp, *dend;
 797	int ret;
 798
 799	/* no leading len */
 800	ret = __ceph_x_decrypt(secret, challenge, challenge_len);
 801	if (ret < 0)
 802		return ret;
 803
 804	dout("%s decrypted %d bytes\n", __func__, ret);
 805	dp = challenge + sizeof(struct ceph_x_encrypt_header);
 806	dend = dp + ret;
 807
 808	ceph_decode_skip_8(&dp, dend, e_inval);  /* struct_v */
 809	ceph_decode_64_safe(&dp, dend, *server_challenge, e_inval);
 810	dout("%s server_challenge %llu\n", __func__, *server_challenge);
 811	return 0;
 812
 813e_inval:
 814	return -EINVAL;
 815}
 816
 817static int ceph_x_add_authorizer_challenge(struct ceph_auth_client *ac,
 818					   struct ceph_authorizer *a,
 819					   void *challenge, int challenge_len)
 820{
 821	struct ceph_x_authorizer *au = (void *)a;
 822	u64 server_challenge;
 823	int ret;
 824
 825	ret = decrypt_authorizer_challenge(&au->session_key, challenge,
 826					   challenge_len, &server_challenge);
 827	if (ret) {
 828		pr_err("failed to decrypt authorize challenge: %d", ret);
 829		return ret;
 830	}
 831
 832	ret = encrypt_authorizer(au, &server_challenge);
 833	if (ret) {
 834		pr_err("failed to encrypt authorizer w/ challenge: %d", ret);
 835		return ret;
 836	}
 837
 838	return 0;
 839}
 840
 841/*
 842 * CephXAuthorizeReply
 843 */
 844static int decrypt_authorizer_reply(struct ceph_crypto_key *secret,
 845				    void **p, void *end, u64 *nonce_plus_one,
 846				    u8 *con_secret, int *con_secret_len)
 847{
 848	void *dp, *dend;
 849	u8 struct_v;
 850	int ret;
 851
 852	dp = *p + ceph_x_encrypt_offset();
 853	ret = ceph_x_decrypt(secret, p, end);
 854	if (ret < 0)
 855		return ret;
 856
 857	dout("%s decrypted %d bytes\n", __func__, ret);
 858	dend = dp + ret;
 859
 860	ceph_decode_8_safe(&dp, dend, struct_v, e_inval);
 861	ceph_decode_64_safe(&dp, dend, *nonce_plus_one, e_inval);
 862	dout("%s nonce_plus_one %llu\n", __func__, *nonce_plus_one);
 863	if (struct_v >= 2) {
 864		ret = decode_con_secret(&dp, dend, con_secret, con_secret_len);
 865		if (ret)
 866			return ret;
 867	}
 868
 869	return 0;
 870
 871e_inval:
 872	return -EINVAL;
 873}
 874
 875static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
 876					  struct ceph_authorizer *a,
 877					  void *reply, int reply_len,
 878					  u8 *session_key, int *session_key_len,
 879					  u8 *con_secret, int *con_secret_len)
 880{
 881	struct ceph_x_authorizer *au = (void *)a;
 882	u64 nonce_plus_one;
 883	int ret;
 884
 885	if (session_key) {
 886		memcpy(session_key, au->session_key.key, au->session_key.len);
 887		*session_key_len = au->session_key.len;
 888	}
 889
 890	ret = decrypt_authorizer_reply(&au->session_key, &reply,
 891				       reply + reply_len, &nonce_plus_one,
 892				       con_secret, con_secret_len);
 893	if (ret)
 894		return ret;
 895
 896	if (nonce_plus_one != au->nonce + 1) {
 897		pr_err("failed to authenticate server\n");
 898		return -EPERM;
 899	}
 900
 901	return 0;
 902}
 903
 904static void ceph_x_reset(struct ceph_auth_client *ac)
 905{
 906	struct ceph_x_info *xi = ac->private;
 907
 908	dout("reset\n");
 909	xi->starting = true;
 910	xi->server_challenge = 0;
 911}
 912
 913static void ceph_x_destroy(struct ceph_auth_client *ac)
 914{
 915	struct ceph_x_info *xi = ac->private;
 916	struct rb_node *p;
 917
 918	dout("ceph_x_destroy %p\n", ac);
 919	ceph_crypto_key_destroy(&xi->secret);
 920
 921	while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
 922		struct ceph_x_ticket_handler *th =
 923			rb_entry(p, struct ceph_x_ticket_handler, node);
 924		remove_ticket_handler(ac, th);
 925	}
 926
 927	ceph_x_authorizer_cleanup(&xi->auth_authorizer);
 928
 929	kfree(ac->private);
 930	ac->private = NULL;
 931}
 932
 933static void invalidate_ticket(struct ceph_auth_client *ac, int peer_type)
 934{
 935	struct ceph_x_ticket_handler *th;
 936
 937	th = get_ticket_handler(ac, peer_type);
 938	if (IS_ERR(th))
 939		return;
 940
 941	if (th->have_key) {
 942		dout("ticket %d (%s) secret_id %llu invalidated\n",
 943		     th->service, ceph_entity_type_name(th->service),
 944		     th->secret_id);
 945		th->have_key = false;
 946	}
 947}
 948
 949static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
 950					 int peer_type)
 951{
 952	/*
 953	 * We are to invalidate a service ticket in the hopes of
 954	 * getting a new, hopefully more valid, one.  But, we won't get
 955	 * it unless our AUTH ticket is good, so invalidate AUTH ticket
 956	 * as well, just in case.
 957	 */
 958	invalidate_ticket(ac, peer_type);
 959	invalidate_ticket(ac, CEPH_ENTITY_TYPE_AUTH);
 960}
 961
 962static int calc_signature(struct ceph_x_authorizer *au, struct ceph_msg *msg,
 963			  __le64 *psig)
 964{
 965	void *enc_buf = au->enc_buf;
 966	int ret;
 967
 968	if (!CEPH_HAVE_FEATURE(msg->con->peer_features, CEPHX_V2)) {
 969		struct {
 970			__le32 len;
 971			__le32 header_crc;
 972			__le32 front_crc;
 973			__le32 middle_crc;
 974			__le32 data_crc;
 975		} __packed *sigblock = enc_buf + ceph_x_encrypt_offset();
 976
 977		sigblock->len = cpu_to_le32(4*sizeof(u32));
 978		sigblock->header_crc = msg->hdr.crc;
 979		sigblock->front_crc = msg->footer.front_crc;
 980		sigblock->middle_crc = msg->footer.middle_crc;
 981		sigblock->data_crc =  msg->footer.data_crc;
 982
 983		ret = ceph_x_encrypt(&au->session_key, enc_buf,
 984				     CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock));
 985		if (ret < 0)
 986			return ret;
 987
 988		*psig = *(__le64 *)(enc_buf + sizeof(u32));
 989	} else {
 990		struct {
 991			__le32 header_crc;
 992			__le32 front_crc;
 993			__le32 front_len;
 994			__le32 middle_crc;
 995			__le32 middle_len;
 996			__le32 data_crc;
 997			__le32 data_len;
 998			__le32 seq_lower_word;
 999		} __packed *sigblock = enc_buf;
1000		struct {
1001			__le64 a, b, c, d;
1002		} __packed *penc = enc_buf;
1003		int ciphertext_len;
1004
1005		sigblock->header_crc = msg->hdr.crc;
1006		sigblock->front_crc = msg->footer.front_crc;
1007		sigblock->front_len = msg->hdr.front_len;
1008		sigblock->middle_crc = msg->footer.middle_crc;
1009		sigblock->middle_len = msg->hdr.middle_len;
1010		sigblock->data_crc =  msg->footer.data_crc;
1011		sigblock->data_len = msg->hdr.data_len;
1012		sigblock->seq_lower_word = *(__le32 *)&msg->hdr.seq;
1013
1014		/* no leading len, no ceph_x_encrypt_header */
1015		ret = ceph_crypt(&au->session_key, true, enc_buf,
1016				 CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock),
1017				 &ciphertext_len);
1018		if (ret)
1019			return ret;
1020
1021		*psig = penc->a ^ penc->b ^ penc->c ^ penc->d;
1022	}
1023
1024	return 0;
1025}
1026
1027static int ceph_x_sign_message(struct ceph_auth_handshake *auth,
1028			       struct ceph_msg *msg)
1029{
1030	__le64 sig;
1031	int ret;
1032
1033	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
1034		return 0;
1035
1036	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
1037			     msg, &sig);
1038	if (ret)
1039		return ret;
1040
1041	msg->footer.sig = sig;
1042	msg->footer.flags |= CEPH_MSG_FOOTER_SIGNED;
1043	return 0;
1044}
1045
1046static int ceph_x_check_message_signature(struct ceph_auth_handshake *auth,
1047					  struct ceph_msg *msg)
1048{
1049	__le64 sig_check;
1050	int ret;
1051
1052	if (ceph_test_opt(from_msgr(msg->con->msgr), NOMSGSIGN))
1053		return 0;
1054
1055	ret = calc_signature((struct ceph_x_authorizer *)auth->authorizer,
1056			     msg, &sig_check);
1057	if (ret)
1058		return ret;
1059	if (sig_check == msg->footer.sig)
1060		return 0;
1061	if (msg->footer.flags & CEPH_MSG_FOOTER_SIGNED)
1062		dout("ceph_x_check_message_signature %p has signature %llx "
1063		     "expect %llx\n", msg, msg->footer.sig, sig_check);
1064	else
1065		dout("ceph_x_check_message_signature %p sender did not set "
1066		     "CEPH_MSG_FOOTER_SIGNED\n", msg);
1067	return -EBADMSG;
1068}
1069
1070static const struct ceph_auth_client_ops ceph_x_ops = {
1071	.is_authenticated = ceph_x_is_authenticated,
1072	.should_authenticate = ceph_x_should_authenticate,
1073	.build_request = ceph_x_build_request,
1074	.handle_reply = ceph_x_handle_reply,
1075	.create_authorizer = ceph_x_create_authorizer,
1076	.update_authorizer = ceph_x_update_authorizer,
1077	.add_authorizer_challenge = ceph_x_add_authorizer_challenge,
1078	.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
1079	.invalidate_authorizer = ceph_x_invalidate_authorizer,
1080	.reset =  ceph_x_reset,
1081	.destroy = ceph_x_destroy,
1082	.sign_message = ceph_x_sign_message,
1083	.check_message_signature = ceph_x_check_message_signature,
1084};
1085
1086
1087int ceph_x_init(struct ceph_auth_client *ac)
1088{
1089	struct ceph_x_info *xi;
1090	int ret;
1091
1092	dout("ceph_x_init %p\n", ac);
1093	ret = -ENOMEM;
1094	xi = kzalloc(sizeof(*xi), GFP_NOFS);
1095	if (!xi)
1096		goto out;
1097
1098	ret = -EINVAL;
1099	if (!ac->key) {
1100		pr_err("no secret set (for auth_x protocol)\n");
1101		goto out_nomem;
1102	}
1103
1104	ret = ceph_crypto_key_clone(&xi->secret, ac->key);
1105	if (ret < 0) {
1106		pr_err("cannot clone key: %d\n", ret);
1107		goto out_nomem;
1108	}
1109
1110	xi->starting = true;
1111	xi->ticket_handlers = RB_ROOT;
1112
1113	ac->protocol = CEPH_AUTH_CEPHX;
1114	ac->private = xi;
1115	ac->ops = &ceph_x_ops;
1116	return 0;
1117
1118out_nomem:
1119	kfree(xi);
1120out:
1121	return ret;
1122}