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   1/* RxRPC key management
   2 *
   3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 *
  11 * RxRPC keys should have a description of describing their purpose:
  12 *	"afs@CAMBRIDGE.REDHAT.COM>
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/net.h>
  17#include <linux/skbuff.h>
  18#include <linux/key-type.h>
  19#include <linux/crypto.h>
  20#include <linux/ctype.h>
  21#include <linux/slab.h>
  22#include <net/sock.h>
  23#include <net/af_rxrpc.h>
  24#include <keys/rxrpc-type.h>
  25#include <keys/user-type.h>
  26#include "ar-internal.h"
  27
  28static int rxrpc_vet_description_s(const char *);
  29static int rxrpc_instantiate(struct key *, const void *, size_t);
  30static int rxrpc_instantiate_s(struct key *, const void *, size_t);
  31static void rxrpc_destroy(struct key *);
  32static void rxrpc_destroy_s(struct key *);
  33static void rxrpc_describe(const struct key *, struct seq_file *);
  34static long rxrpc_read(const struct key *, char __user *, size_t);
  35
  36/*
  37 * rxrpc defined keys take an arbitrary string as the description and an
  38 * arbitrary blob of data as the payload
  39 */
  40struct key_type key_type_rxrpc = {
  41	.name		= "rxrpc",
  42	.instantiate	= rxrpc_instantiate,
  43	.match		= user_match,
  44	.destroy	= rxrpc_destroy,
  45	.describe	= rxrpc_describe,
  46	.read		= rxrpc_read,
  47};
  48EXPORT_SYMBOL(key_type_rxrpc);
  49
  50/*
  51 * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
  52 * description and an 8-byte decryption key as the payload
  53 */
  54struct key_type key_type_rxrpc_s = {
  55	.name		= "rxrpc_s",
  56	.vet_description = rxrpc_vet_description_s,
  57	.instantiate	= rxrpc_instantiate_s,
  58	.match		= user_match,
  59	.destroy	= rxrpc_destroy_s,
  60	.describe	= rxrpc_describe,
  61};
  62
  63/*
  64 * Vet the description for an RxRPC server key
  65 */
  66static int rxrpc_vet_description_s(const char *desc)
  67{
  68	unsigned long num;
  69	char *p;
  70
  71	num = simple_strtoul(desc, &p, 10);
  72	if (*p != ':' || num > 65535)
  73		return -EINVAL;
  74	num = simple_strtoul(p + 1, &p, 10);
  75	if (*p || num < 1 || num > 255)
  76		return -EINVAL;
  77	return 0;
  78}
  79
  80/*
  81 * parse an RxKAD type XDR format token
  82 * - the caller guarantees we have at least 4 words
  83 */
  84static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
  85				       unsigned toklen)
  86{
  87	struct rxrpc_key_token *token, **pptoken;
  88	size_t plen;
  89	u32 tktlen;
  90	int ret;
  91
  92	_enter(",{%x,%x,%x,%x},%u",
  93	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
  94	       toklen);
  95
  96	if (toklen <= 8 * 4)
  97		return -EKEYREJECTED;
  98	tktlen = ntohl(xdr[7]);
  99	_debug("tktlen: %x", tktlen);
 100	if (tktlen > AFSTOKEN_RK_TIX_MAX)
 101		return -EKEYREJECTED;
 102	if (8 * 4 + tktlen != toklen)
 103		return -EKEYREJECTED;
 104
 105	plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
 106	ret = key_payload_reserve(key, key->datalen + plen);
 107	if (ret < 0)
 108		return ret;
 109
 110	plen -= sizeof(*token);
 111	token = kzalloc(sizeof(*token), GFP_KERNEL);
 112	if (!token)
 113		return -ENOMEM;
 114
 115	token->kad = kzalloc(plen, GFP_KERNEL);
 116	if (!token->kad) {
 117		kfree(token);
 118		return -ENOMEM;
 119	}
 120
 121	token->security_index	= RXRPC_SECURITY_RXKAD;
 122	token->kad->ticket_len	= tktlen;
 123	token->kad->vice_id	= ntohl(xdr[0]);
 124	token->kad->kvno	= ntohl(xdr[1]);
 125	token->kad->start	= ntohl(xdr[4]);
 126	token->kad->expiry	= ntohl(xdr[5]);
 127	token->kad->primary_flag = ntohl(xdr[6]);
 128	memcpy(&token->kad->session_key, &xdr[2], 8);
 129	memcpy(&token->kad->ticket, &xdr[8], tktlen);
 130
 131	_debug("SCIX: %u", token->security_index);
 132	_debug("TLEN: %u", token->kad->ticket_len);
 133	_debug("EXPY: %x", token->kad->expiry);
 134	_debug("KVNO: %u", token->kad->kvno);
 135	_debug("PRIM: %u", token->kad->primary_flag);
 136	_debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
 137	       token->kad->session_key[0], token->kad->session_key[1],
 138	       token->kad->session_key[2], token->kad->session_key[3],
 139	       token->kad->session_key[4], token->kad->session_key[5],
 140	       token->kad->session_key[6], token->kad->session_key[7]);
 141	if (token->kad->ticket_len >= 8)
 142		_debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
 143		       token->kad->ticket[0], token->kad->ticket[1],
 144		       token->kad->ticket[2], token->kad->ticket[3],
 145		       token->kad->ticket[4], token->kad->ticket[5],
 146		       token->kad->ticket[6], token->kad->ticket[7]);
 147
 148	/* count the number of tokens attached */
 149	key->type_data.x[0]++;
 150
 151	/* attach the data */
 152	for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
 153	     *pptoken;
 154	     pptoken = &(*pptoken)->next)
 155		continue;
 156	*pptoken = token;
 157	if (token->kad->expiry < key->expiry)
 158		key->expiry = token->kad->expiry;
 159
 160	_leave(" = 0");
 161	return 0;
 162}
 163
 164static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
 165{
 166	int loop;
 167
 168	if (princ->name_parts) {
 169		for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
 170			kfree(princ->name_parts[loop]);
 171		kfree(princ->name_parts);
 172	}
 173	kfree(princ->realm);
 174}
 175
 176static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
 177{
 178	kfree(td->data);
 179}
 180
 181/*
 182 * free up an RxK5 token
 183 */
 184static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
 185{
 186	int loop;
 187
 188	rxrpc_free_krb5_principal(&rxk5->client);
 189	rxrpc_free_krb5_principal(&rxk5->server);
 190	rxrpc_free_krb5_tagged(&rxk5->session);
 191
 192	if (rxk5->addresses) {
 193		for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
 194			rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
 195		kfree(rxk5->addresses);
 196	}
 197	if (rxk5->authdata) {
 198		for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
 199			rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
 200		kfree(rxk5->authdata);
 201	}
 202
 203	kfree(rxk5->ticket);
 204	kfree(rxk5->ticket2);
 205	kfree(rxk5);
 206}
 207
 208/*
 209 * extract a krb5 principal
 210 */
 211static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
 212				       const __be32 **_xdr,
 213				       unsigned *_toklen)
 214{
 215	const __be32 *xdr = *_xdr;
 216	unsigned toklen = *_toklen, n_parts, loop, tmp;
 217
 218	/* there must be at least one name, and at least #names+1 length
 219	 * words */
 220	if (toklen <= 12)
 221		return -EINVAL;
 222
 223	_enter(",{%x,%x,%x},%u",
 224	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
 225
 226	n_parts = ntohl(*xdr++);
 227	toklen -= 4;
 228	if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
 229		return -EINVAL;
 230	princ->n_name_parts = n_parts;
 231
 232	if (toklen <= (n_parts + 1) * 4)
 233		return -EINVAL;
 234
 235	princ->name_parts = kcalloc(sizeof(char *), n_parts, GFP_KERNEL);
 236	if (!princ->name_parts)
 237		return -ENOMEM;
 238
 239	for (loop = 0; loop < n_parts; loop++) {
 240		if (toklen < 4)
 241			return -EINVAL;
 242		tmp = ntohl(*xdr++);
 243		toklen -= 4;
 244		if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
 245			return -EINVAL;
 246		if (tmp > toklen)
 247			return -EINVAL;
 248		princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
 249		if (!princ->name_parts[loop])
 250			return -ENOMEM;
 251		memcpy(princ->name_parts[loop], xdr, tmp);
 252		princ->name_parts[loop][tmp] = 0;
 253		tmp = (tmp + 3) & ~3;
 254		toklen -= tmp;
 255		xdr += tmp >> 2;
 256	}
 257
 258	if (toklen < 4)
 259		return -EINVAL;
 260	tmp = ntohl(*xdr++);
 261	toklen -= 4;
 262	if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
 263		return -EINVAL;
 264	if (tmp > toklen)
 265		return -EINVAL;
 266	princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
 267	if (!princ->realm)
 268		return -ENOMEM;
 269	memcpy(princ->realm, xdr, tmp);
 270	princ->realm[tmp] = 0;
 271	tmp = (tmp + 3) & ~3;
 272	toklen -= tmp;
 273	xdr += tmp >> 2;
 274
 275	_debug("%s/...@%s", princ->name_parts[0], princ->realm);
 276
 277	*_xdr = xdr;
 278	*_toklen = toklen;
 279	_leave(" = 0 [toklen=%u]", toklen);
 280	return 0;
 281}
 282
 283/*
 284 * extract a piece of krb5 tagged data
 285 */
 286static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
 287					 size_t max_data_size,
 288					 const __be32 **_xdr,
 289					 unsigned *_toklen)
 290{
 291	const __be32 *xdr = *_xdr;
 292	unsigned toklen = *_toklen, len;
 293
 294	/* there must be at least one tag and one length word */
 295	if (toklen <= 8)
 296		return -EINVAL;
 297
 298	_enter(",%zu,{%x,%x},%u",
 299	       max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
 300
 301	td->tag = ntohl(*xdr++);
 302	len = ntohl(*xdr++);
 303	toklen -= 8;
 304	if (len > max_data_size)
 305		return -EINVAL;
 306	td->data_len = len;
 307
 308	if (len > 0) {
 309		td->data = kmalloc(len, GFP_KERNEL);
 310		if (!td->data)
 311			return -ENOMEM;
 312		memcpy(td->data, xdr, len);
 313		len = (len + 3) & ~3;
 314		toklen -= len;
 315		xdr += len >> 2;
 316	}
 317
 318	_debug("tag %x len %x", td->tag, td->data_len);
 319
 320	*_xdr = xdr;
 321	*_toklen = toklen;
 322	_leave(" = 0 [toklen=%u]", toklen);
 323	return 0;
 324}
 325
 326/*
 327 * extract an array of tagged data
 328 */
 329static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
 330					  u8 *_n_elem,
 331					  u8 max_n_elem,
 332					  size_t max_elem_size,
 333					  const __be32 **_xdr,
 334					  unsigned *_toklen)
 335{
 336	struct krb5_tagged_data *td;
 337	const __be32 *xdr = *_xdr;
 338	unsigned toklen = *_toklen, n_elem, loop;
 339	int ret;
 340
 341	/* there must be at least one count */
 342	if (toklen < 4)
 343		return -EINVAL;
 344
 345	_enter(",,%u,%zu,{%x},%u",
 346	       max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
 347
 348	n_elem = ntohl(*xdr++);
 349	toklen -= 4;
 350	if (n_elem < 0 || n_elem > max_n_elem)
 351		return -EINVAL;
 352	*_n_elem = n_elem;
 353	if (n_elem > 0) {
 354		if (toklen <= (n_elem + 1) * 4)
 355			return -EINVAL;
 356
 357		_debug("n_elem %d", n_elem);
 358
 359		td = kcalloc(sizeof(struct krb5_tagged_data), n_elem,
 360			     GFP_KERNEL);
 361		if (!td)
 362			return -ENOMEM;
 363		*_td = td;
 364
 365		for (loop = 0; loop < n_elem; loop++) {
 366			ret = rxrpc_krb5_decode_tagged_data(&td[loop],
 367							    max_elem_size,
 368							    &xdr, &toklen);
 369			if (ret < 0)
 370				return ret;
 371		}
 372	}
 373
 374	*_xdr = xdr;
 375	*_toklen = toklen;
 376	_leave(" = 0 [toklen=%u]", toklen);
 377	return 0;
 378}
 379
 380/*
 381 * extract a krb5 ticket
 382 */
 383static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
 384				    const __be32 **_xdr, unsigned *_toklen)
 385{
 386	const __be32 *xdr = *_xdr;
 387	unsigned toklen = *_toklen, len;
 388
 389	/* there must be at least one length word */
 390	if (toklen <= 4)
 391		return -EINVAL;
 392
 393	_enter(",{%x},%u", ntohl(xdr[0]), toklen);
 394
 395	len = ntohl(*xdr++);
 396	toklen -= 4;
 397	if (len > AFSTOKEN_K5_TIX_MAX)
 398		return -EINVAL;
 399	*_tktlen = len;
 400
 401	_debug("ticket len %u", len);
 402
 403	if (len > 0) {
 404		*_ticket = kmalloc(len, GFP_KERNEL);
 405		if (!*_ticket)
 406			return -ENOMEM;
 407		memcpy(*_ticket, xdr, len);
 408		len = (len + 3) & ~3;
 409		toklen -= len;
 410		xdr += len >> 2;
 411	}
 412
 413	*_xdr = xdr;
 414	*_toklen = toklen;
 415	_leave(" = 0 [toklen=%u]", toklen);
 416	return 0;
 417}
 418
 419/*
 420 * parse an RxK5 type XDR format token
 421 * - the caller guarantees we have at least 4 words
 422 */
 423static int rxrpc_instantiate_xdr_rxk5(struct key *key, const __be32 *xdr,
 424				      unsigned toklen)
 425{
 426	struct rxrpc_key_token *token, **pptoken;
 427	struct rxk5_key *rxk5;
 428	const __be32 *end_xdr = xdr + (toklen >> 2);
 429	int ret;
 430
 431	_enter(",{%x,%x,%x,%x},%u",
 432	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
 433	       toklen);
 434
 435	/* reserve some payload space for this subkey - the length of the token
 436	 * is a reasonable approximation */
 437	ret = key_payload_reserve(key, key->datalen + toklen);
 438	if (ret < 0)
 439		return ret;
 440
 441	token = kzalloc(sizeof(*token), GFP_KERNEL);
 442	if (!token)
 443		return -ENOMEM;
 444
 445	rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
 446	if (!rxk5) {
 447		kfree(token);
 448		return -ENOMEM;
 449	}
 450
 451	token->security_index = RXRPC_SECURITY_RXK5;
 452	token->k5 = rxk5;
 453
 454	/* extract the principals */
 455	ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
 456	if (ret < 0)
 457		goto error;
 458	ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
 459	if (ret < 0)
 460		goto error;
 461
 462	/* extract the session key and the encoding type (the tag field ->
 463	 * ENCTYPE_xxx) */
 464	ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
 465					    &xdr, &toklen);
 466	if (ret < 0)
 467		goto error;
 468
 469	if (toklen < 4 * 8 + 2 * 4)
 470		goto inval;
 471	rxk5->authtime	= be64_to_cpup((const __be64 *) xdr);
 472	xdr += 2;
 473	rxk5->starttime	= be64_to_cpup((const __be64 *) xdr);
 474	xdr += 2;
 475	rxk5->endtime	= be64_to_cpup((const __be64 *) xdr);
 476	xdr += 2;
 477	rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
 478	xdr += 2;
 479	rxk5->is_skey = ntohl(*xdr++);
 480	rxk5->flags = ntohl(*xdr++);
 481	toklen -= 4 * 8 + 2 * 4;
 482
 483	_debug("times: a=%llx s=%llx e=%llx rt=%llx",
 484	       rxk5->authtime, rxk5->starttime, rxk5->endtime,
 485	       rxk5->renew_till);
 486	_debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
 487
 488	/* extract the permitted client addresses */
 489	ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
 490					     &rxk5->n_addresses,
 491					     AFSTOKEN_K5_ADDRESSES_MAX,
 492					     AFSTOKEN_DATA_MAX,
 493					     &xdr, &toklen);
 494	if (ret < 0)
 495		goto error;
 496
 497	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 498
 499	/* extract the tickets */
 500	ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
 501				       &xdr, &toklen);
 502	if (ret < 0)
 503		goto error;
 504	ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
 505				       &xdr, &toklen);
 506	if (ret < 0)
 507		goto error;
 508
 509	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 510
 511	/* extract the typed auth data */
 512	ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
 513					     &rxk5->n_authdata,
 514					     AFSTOKEN_K5_AUTHDATA_MAX,
 515					     AFSTOKEN_BDATALN_MAX,
 516					     &xdr, &toklen);
 517	if (ret < 0)
 518		goto error;
 519
 520	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 521
 522	if (toklen != 0)
 523		goto inval;
 524
 525	/* attach the payload to the key */
 526	for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
 527	     *pptoken;
 528	     pptoken = &(*pptoken)->next)
 529		continue;
 530	*pptoken = token;
 531	if (token->kad->expiry < key->expiry)
 532		key->expiry = token->kad->expiry;
 533
 534	_leave(" = 0");
 535	return 0;
 536
 537inval:
 538	ret = -EINVAL;
 539error:
 540	rxrpc_rxk5_free(rxk5);
 541	kfree(token);
 542	_leave(" = %d", ret);
 543	return ret;
 544}
 545
 546/*
 547 * attempt to parse the data as the XDR format
 548 * - the caller guarantees we have more than 7 words
 549 */
 550static int rxrpc_instantiate_xdr(struct key *key, const void *data, size_t datalen)
 551{
 552	const __be32 *xdr = data, *token;
 553	const char *cp;
 554	unsigned len, tmp, loop, ntoken, toklen, sec_ix;
 555	int ret;
 556
 557	_enter(",{%x,%x,%x,%x},%zu",
 558	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
 559	       datalen);
 560
 561	if (datalen > AFSTOKEN_LENGTH_MAX)
 562		goto not_xdr;
 563
 564	/* XDR is an array of __be32's */
 565	if (datalen & 3)
 566		goto not_xdr;
 567
 568	/* the flags should be 0 (the setpag bit must be handled by
 569	 * userspace) */
 570	if (ntohl(*xdr++) != 0)
 571		goto not_xdr;
 572	datalen -= 4;
 573
 574	/* check the cell name */
 575	len = ntohl(*xdr++);
 576	if (len < 1 || len > AFSTOKEN_CELL_MAX)
 577		goto not_xdr;
 578	datalen -= 4;
 579	tmp = (len + 3) & ~3;
 580	if (tmp > datalen)
 581		goto not_xdr;
 582
 583	cp = (const char *) xdr;
 584	for (loop = 0; loop < len; loop++)
 585		if (!isprint(cp[loop]))
 586			goto not_xdr;
 587	if (len < tmp)
 588		for (; loop < tmp; loop++)
 589			if (cp[loop])
 590				goto not_xdr;
 591	_debug("cellname: [%u/%u] '%*.*s'",
 592	       len, tmp, len, len, (const char *) xdr);
 593	datalen -= tmp;
 594	xdr += tmp >> 2;
 595
 596	/* get the token count */
 597	if (datalen < 12)
 598		goto not_xdr;
 599	ntoken = ntohl(*xdr++);
 600	datalen -= 4;
 601	_debug("ntoken: %x", ntoken);
 602	if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
 603		goto not_xdr;
 604
 605	/* check each token wrapper */
 606	token = xdr;
 607	loop = ntoken;
 608	do {
 609		if (datalen < 8)
 610			goto not_xdr;
 611		toklen = ntohl(*xdr++);
 612		sec_ix = ntohl(*xdr);
 613		datalen -= 4;
 614		_debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
 615		if (toklen < 20 || toklen > datalen)
 616			goto not_xdr;
 617		datalen -= (toklen + 3) & ~3;
 618		xdr += (toklen + 3) >> 2;
 619
 620	} while (--loop > 0);
 621
 622	_debug("remainder: %zu", datalen);
 623	if (datalen != 0)
 624		goto not_xdr;
 625
 626	/* okay: we're going to assume it's valid XDR format
 627	 * - we ignore the cellname, relying on the key to be correctly named
 628	 */
 629	do {
 630		xdr = token;
 631		toklen = ntohl(*xdr++);
 632		token = xdr + ((toklen + 3) >> 2);
 633		sec_ix = ntohl(*xdr++);
 634		toklen -= 4;
 635
 636		_debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
 637
 638		switch (sec_ix) {
 639		case RXRPC_SECURITY_RXKAD:
 640			ret = rxrpc_instantiate_xdr_rxkad(key, xdr, toklen);
 641			if (ret != 0)
 642				goto error;
 643			break;
 644
 645		case RXRPC_SECURITY_RXK5:
 646			ret = rxrpc_instantiate_xdr_rxk5(key, xdr, toklen);
 647			if (ret != 0)
 648				goto error;
 649			break;
 650
 651		default:
 652			ret = -EPROTONOSUPPORT;
 653			goto error;
 654		}
 655
 656	} while (--ntoken > 0);
 657
 658	_leave(" = 0");
 659	return 0;
 660
 661not_xdr:
 662	_leave(" = -EPROTO");
 663	return -EPROTO;
 664error:
 665	_leave(" = %d", ret);
 666	return ret;
 667}
 668
 669/*
 670 * instantiate an rxrpc defined key
 671 * data should be of the form:
 672 *	OFFSET	LEN	CONTENT
 673 *	0	4	key interface version number
 674 *	4	2	security index (type)
 675 *	6	2	ticket length
 676 *	8	4	key expiry time (time_t)
 677 *	12	4	kvno
 678 *	16	8	session key
 679 *	24	[len]	ticket
 680 *
 681 * if no data is provided, then a no-security key is made
 682 */
 683static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen)
 684{
 685	const struct rxrpc_key_data_v1 *v1;
 686	struct rxrpc_key_token *token, **pp;
 687	size_t plen;
 688	u32 kver;
 689	int ret;
 690
 691	_enter("{%x},,%zu", key_serial(key), datalen);
 692
 693	/* handle a no-security key */
 694	if (!data && datalen == 0)
 695		return 0;
 696
 697	/* determine if the XDR payload format is being used */
 698	if (datalen > 7 * 4) {
 699		ret = rxrpc_instantiate_xdr(key, data, datalen);
 700		if (ret != -EPROTO)
 701			return ret;
 702	}
 703
 704	/* get the key interface version number */
 705	ret = -EINVAL;
 706	if (datalen <= 4 || !data)
 707		goto error;
 708	memcpy(&kver, data, sizeof(kver));
 709	data += sizeof(kver);
 710	datalen -= sizeof(kver);
 711
 712	_debug("KEY I/F VERSION: %u", kver);
 713
 714	ret = -EKEYREJECTED;
 715	if (kver != 1)
 716		goto error;
 717
 718	/* deal with a version 1 key */
 719	ret = -EINVAL;
 720	if (datalen < sizeof(*v1))
 721		goto error;
 722
 723	v1 = data;
 724	if (datalen != sizeof(*v1) + v1->ticket_length)
 725		goto error;
 726
 727	_debug("SCIX: %u", v1->security_index);
 728	_debug("TLEN: %u", v1->ticket_length);
 729	_debug("EXPY: %x", v1->expiry);
 730	_debug("KVNO: %u", v1->kvno);
 731	_debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
 732	       v1->session_key[0], v1->session_key[1],
 733	       v1->session_key[2], v1->session_key[3],
 734	       v1->session_key[4], v1->session_key[5],
 735	       v1->session_key[6], v1->session_key[7]);
 736	if (v1->ticket_length >= 8)
 737		_debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
 738		       v1->ticket[0], v1->ticket[1],
 739		       v1->ticket[2], v1->ticket[3],
 740		       v1->ticket[4], v1->ticket[5],
 741		       v1->ticket[6], v1->ticket[7]);
 742
 743	ret = -EPROTONOSUPPORT;
 744	if (v1->security_index != RXRPC_SECURITY_RXKAD)
 745		goto error;
 746
 747	plen = sizeof(*token->kad) + v1->ticket_length;
 748	ret = key_payload_reserve(key, plen + sizeof(*token));
 749	if (ret < 0)
 750		goto error;
 751
 752	ret = -ENOMEM;
 753	token = kzalloc(sizeof(*token), GFP_KERNEL);
 754	if (!token)
 755		goto error;
 756	token->kad = kzalloc(plen, GFP_KERNEL);
 757	if (!token->kad)
 758		goto error_free;
 759
 760	token->security_index		= RXRPC_SECURITY_RXKAD;
 761	token->kad->ticket_len		= v1->ticket_length;
 762	token->kad->expiry		= v1->expiry;
 763	token->kad->kvno		= v1->kvno;
 764	memcpy(&token->kad->session_key, &v1->session_key, 8);
 765	memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
 766
 767	/* attach the data */
 768	key->type_data.x[0]++;
 769
 770	pp = (struct rxrpc_key_token **)&key->payload.data;
 771	while (*pp)
 772		pp = &(*pp)->next;
 773	*pp = token;
 774	if (token->kad->expiry < key->expiry)
 775		key->expiry = token->kad->expiry;
 776	token = NULL;
 777	ret = 0;
 778
 779error_free:
 780	kfree(token);
 781error:
 782	return ret;
 783}
 784
 785/*
 786 * instantiate a server secret key
 787 * data should be a pointer to the 8-byte secret key
 788 */
 789static int rxrpc_instantiate_s(struct key *key, const void *data,
 790			       size_t datalen)
 791{
 792	struct crypto_blkcipher *ci;
 793
 794	_enter("{%x},,%zu", key_serial(key), datalen);
 795
 796	if (datalen != 8)
 797		return -EINVAL;
 798
 799	memcpy(&key->type_data, data, 8);
 800
 801	ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
 802	if (IS_ERR(ci)) {
 803		_leave(" = %ld", PTR_ERR(ci));
 804		return PTR_ERR(ci);
 805	}
 806
 807	if (crypto_blkcipher_setkey(ci, data, 8) < 0)
 808		BUG();
 809
 810	key->payload.data = ci;
 811	_leave(" = 0");
 812	return 0;
 813}
 814
 815/*
 816 * dispose of the data dangling from the corpse of a rxrpc key
 817 */
 818static void rxrpc_destroy(struct key *key)
 819{
 820	struct rxrpc_key_token *token;
 821
 822	while ((token = key->payload.data)) {
 823		key->payload.data = token->next;
 824		switch (token->security_index) {
 825		case RXRPC_SECURITY_RXKAD:
 826			kfree(token->kad);
 827			break;
 828		case RXRPC_SECURITY_RXK5:
 829			if (token->k5)
 830				rxrpc_rxk5_free(token->k5);
 831			break;
 832		default:
 833			printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
 834			       token->security_index);
 835			BUG();
 836		}
 837
 838		kfree(token);
 839	}
 840}
 841
 842/*
 843 * dispose of the data dangling from the corpse of a rxrpc key
 844 */
 845static void rxrpc_destroy_s(struct key *key)
 846{
 847	if (key->payload.data) {
 848		crypto_free_blkcipher(key->payload.data);
 849		key->payload.data = NULL;
 850	}
 851}
 852
 853/*
 854 * describe the rxrpc key
 855 */
 856static void rxrpc_describe(const struct key *key, struct seq_file *m)
 857{
 858	seq_puts(m, key->description);
 859}
 860
 861/*
 862 * grab the security key for a socket
 863 */
 864int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
 865{
 866	struct key *key;
 867	char *description;
 868
 869	_enter("");
 870
 871	if (optlen <= 0 || optlen > PAGE_SIZE - 1)
 872		return -EINVAL;
 873
 874	description = kmalloc(optlen + 1, GFP_KERNEL);
 875	if (!description)
 876		return -ENOMEM;
 877
 878	if (copy_from_user(description, optval, optlen)) {
 879		kfree(description);
 880		return -EFAULT;
 881	}
 882	description[optlen] = 0;
 883
 884	key = request_key(&key_type_rxrpc, description, NULL);
 885	if (IS_ERR(key)) {
 886		kfree(description);
 887		_leave(" = %ld", PTR_ERR(key));
 888		return PTR_ERR(key);
 889	}
 890
 891	rx->key = key;
 892	kfree(description);
 893	_leave(" = 0 [key %x]", key->serial);
 894	return 0;
 895}
 896
 897/*
 898 * grab the security keyring for a server socket
 899 */
 900int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
 901			 int optlen)
 902{
 903	struct key *key;
 904	char *description;
 905
 906	_enter("");
 907
 908	if (optlen <= 0 || optlen > PAGE_SIZE - 1)
 909		return -EINVAL;
 910
 911	description = kmalloc(optlen + 1, GFP_KERNEL);
 912	if (!description)
 913		return -ENOMEM;
 914
 915	if (copy_from_user(description, optval, optlen)) {
 916		kfree(description);
 917		return -EFAULT;
 918	}
 919	description[optlen] = 0;
 920
 921	key = request_key(&key_type_keyring, description, NULL);
 922	if (IS_ERR(key)) {
 923		kfree(description);
 924		_leave(" = %ld", PTR_ERR(key));
 925		return PTR_ERR(key);
 926	}
 927
 928	rx->securities = key;
 929	kfree(description);
 930	_leave(" = 0 [key %x]", key->serial);
 931	return 0;
 932}
 933
 934/*
 935 * generate a server data key
 936 */
 937int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
 938			      const void *session_key,
 939			      time_t expiry,
 940			      u32 kvno)
 941{
 942	const struct cred *cred = current_cred();
 943	struct key *key;
 944	int ret;
 945
 946	struct {
 947		u32 kver;
 948		struct rxrpc_key_data_v1 v1;
 949	} data;
 950
 951	_enter("");
 952
 953	key = key_alloc(&key_type_rxrpc, "x", 0, 0, cred, 0,
 954			KEY_ALLOC_NOT_IN_QUOTA);
 955	if (IS_ERR(key)) {
 956		_leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
 957		return -ENOMEM;
 958	}
 959
 960	_debug("key %d", key_serial(key));
 961
 962	data.kver = 1;
 963	data.v1.security_index = RXRPC_SECURITY_RXKAD;
 964	data.v1.ticket_length = 0;
 965	data.v1.expiry = expiry;
 966	data.v1.kvno = 0;
 967
 968	memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
 969
 970	ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
 971	if (ret < 0)
 972		goto error;
 973
 974	conn->key = key;
 975	_leave(" = 0 [%d]", key_serial(key));
 976	return 0;
 977
 978error:
 979	key_revoke(key);
 980	key_put(key);
 981	_leave(" = -ENOMEM [ins %d]", ret);
 982	return -ENOMEM;
 983}
 984EXPORT_SYMBOL(rxrpc_get_server_data_key);
 985
 986/**
 987 * rxrpc_get_null_key - Generate a null RxRPC key
 988 * @keyname: The name to give the key.
 989 *
 990 * Generate a null RxRPC key that can be used to indicate anonymous security is
 991 * required for a particular domain.
 992 */
 993struct key *rxrpc_get_null_key(const char *keyname)
 994{
 995	const struct cred *cred = current_cred();
 996	struct key *key;
 997	int ret;
 998
 999	key = key_alloc(&key_type_rxrpc, keyname, 0, 0, cred,
1000			KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
1001	if (IS_ERR(key))
1002		return key;
1003
1004	ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
1005	if (ret < 0) {
1006		key_revoke(key);
1007		key_put(key);
1008		return ERR_PTR(ret);
1009	}
1010
1011	return key;
1012}
1013EXPORT_SYMBOL(rxrpc_get_null_key);
1014
1015/*
1016 * read the contents of an rxrpc key
1017 * - this returns the result in XDR form
1018 */
1019static long rxrpc_read(const struct key *key,
1020		       char __user *buffer, size_t buflen)
1021{
1022	const struct rxrpc_key_token *token;
1023	const struct krb5_principal *princ;
1024	size_t size;
1025	__be32 __user *xdr, *oldxdr;
1026	u32 cnlen, toksize, ntoks, tok, zero;
1027	u16 toksizes[AFSTOKEN_MAX];
1028	int loop;
1029
1030	_enter("");
1031
1032	/* we don't know what form we should return non-AFS keys in */
1033	if (memcmp(key->description, "afs@", 4) != 0)
1034		return -EOPNOTSUPP;
1035	cnlen = strlen(key->description + 4);
1036
1037#define RND(X) (((X) + 3) & ~3)
1038
1039	/* AFS keys we return in XDR form, so we need to work out the size of
1040	 * the XDR */
1041	size = 2 * 4;	/* flags, cellname len */
1042	size += RND(cnlen);	/* cellname */
1043	size += 1 * 4;	/* token count */
1044
1045	ntoks = 0;
1046	for (token = key->payload.data; token; token = token->next) {
1047		toksize = 4;	/* sec index */
1048
1049		switch (token->security_index) {
1050		case RXRPC_SECURITY_RXKAD:
1051			toksize += 8 * 4;	/* viceid, kvno, key*2, begin,
1052						 * end, primary, tktlen */
1053			toksize += RND(token->kad->ticket_len);
1054			break;
1055
1056		case RXRPC_SECURITY_RXK5:
1057			princ = &token->k5->client;
1058			toksize += 4 + princ->n_name_parts * 4;
1059			for (loop = 0; loop < princ->n_name_parts; loop++)
1060				toksize += RND(strlen(princ->name_parts[loop]));
1061			toksize += 4 + RND(strlen(princ->realm));
1062
1063			princ = &token->k5->server;
1064			toksize += 4 + princ->n_name_parts * 4;
1065			for (loop = 0; loop < princ->n_name_parts; loop++)
1066				toksize += RND(strlen(princ->name_parts[loop]));
1067			toksize += 4 + RND(strlen(princ->realm));
1068
1069			toksize += 8 + RND(token->k5->session.data_len);
1070
1071			toksize += 4 * 8 + 2 * 4;
1072
1073			toksize += 4 + token->k5->n_addresses * 8;
1074			for (loop = 0; loop < token->k5->n_addresses; loop++)
1075				toksize += RND(token->k5->addresses[loop].data_len);
1076
1077			toksize += 4 + RND(token->k5->ticket_len);
1078			toksize += 4 + RND(token->k5->ticket2_len);
1079
1080			toksize += 4 + token->k5->n_authdata * 8;
1081			for (loop = 0; loop < token->k5->n_authdata; loop++)
1082				toksize += RND(token->k5->authdata[loop].data_len);
1083			break;
1084
1085		default: /* we have a ticket we can't encode */
1086			BUG();
1087			continue;
1088		}
1089
1090		_debug("token[%u]: toksize=%u", ntoks, toksize);
1091		ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
1092
1093		toksizes[ntoks++] = toksize;
1094		size += toksize + 4; /* each token has a length word */
1095	}
1096
1097#undef RND
1098
1099	if (!buffer || buflen < size)
1100		return size;
1101
1102	xdr = (__be32 __user *) buffer;
1103	zero = 0;
1104#define ENCODE(x)				\
1105	do {					\
1106		__be32 y = htonl(x);		\
1107		if (put_user(y, xdr++) < 0)	\
1108			goto fault;		\
1109	} while(0)
1110#define ENCODE_DATA(l, s)						\
1111	do {								\
1112		u32 _l = (l);						\
1113		ENCODE(l);						\
1114		if (copy_to_user(xdr, (s), _l) != 0)			\
1115			goto fault;					\
1116		if (_l & 3 &&						\
1117		    copy_to_user((u8 *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
1118			goto fault;					\
1119		xdr += (_l + 3) >> 2;					\
1120	} while(0)
1121#define ENCODE64(x)					\
1122	do {						\
1123		__be64 y = cpu_to_be64(x);		\
1124		if (copy_to_user(xdr, &y, 8) != 0)	\
1125			goto fault;			\
1126		xdr += 8 >> 2;				\
1127	} while(0)
1128#define ENCODE_STR(s)				\
1129	do {					\
1130		const char *_s = (s);		\
1131		ENCODE_DATA(strlen(_s), _s);	\
1132	} while(0)
1133
1134	ENCODE(0);					/* flags */
1135	ENCODE_DATA(cnlen, key->description + 4);	/* cellname */
1136	ENCODE(ntoks);
1137
1138	tok = 0;
1139	for (token = key->payload.data; token; token = token->next) {
1140		toksize = toksizes[tok++];
1141		ENCODE(toksize);
1142		oldxdr = xdr;
1143		ENCODE(token->security_index);
1144
1145		switch (token->security_index) {
1146		case RXRPC_SECURITY_RXKAD:
1147			ENCODE(token->kad->vice_id);
1148			ENCODE(token->kad->kvno);
1149			ENCODE_DATA(8, token->kad->session_key);
1150			ENCODE(token->kad->start);
1151			ENCODE(token->kad->expiry);
1152			ENCODE(token->kad->primary_flag);
1153			ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
1154			break;
1155
1156		case RXRPC_SECURITY_RXK5:
1157			princ = &token->k5->client;
1158			ENCODE(princ->n_name_parts);
1159			for (loop = 0; loop < princ->n_name_parts; loop++)
1160				ENCODE_STR(princ->name_parts[loop]);
1161			ENCODE_STR(princ->realm);
1162
1163			princ = &token->k5->server;
1164			ENCODE(princ->n_name_parts);
1165			for (loop = 0; loop < princ->n_name_parts; loop++)
1166				ENCODE_STR(princ->name_parts[loop]);
1167			ENCODE_STR(princ->realm);
1168
1169			ENCODE(token->k5->session.tag);
1170			ENCODE_DATA(token->k5->session.data_len,
1171				    token->k5->session.data);
1172
1173			ENCODE64(token->k5->authtime);
1174			ENCODE64(token->k5->starttime);
1175			ENCODE64(token->k5->endtime);
1176			ENCODE64(token->k5->renew_till);
1177			ENCODE(token->k5->is_skey);
1178			ENCODE(token->k5->flags);
1179
1180			ENCODE(token->k5->n_addresses);
1181			for (loop = 0; loop < token->k5->n_addresses; loop++) {
1182				ENCODE(token->k5->addresses[loop].tag);
1183				ENCODE_DATA(token->k5->addresses[loop].data_len,
1184					    token->k5->addresses[loop].data);
1185			}
1186
1187			ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
1188			ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
1189
1190			ENCODE(token->k5->n_authdata);
1191			for (loop = 0; loop < token->k5->n_authdata; loop++) {
1192				ENCODE(token->k5->authdata[loop].tag);
1193				ENCODE_DATA(token->k5->authdata[loop].data_len,
1194					    token->k5->authdata[loop].data);
1195			}
1196			break;
1197
1198		default:
1199			BUG();
1200			break;
1201		}
1202
1203		ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
1204			  toksize);
1205	}
1206
1207#undef ENCODE_STR
1208#undef ENCODE_DATA
1209#undef ENCODE64
1210#undef ENCODE
1211
1212	ASSERTCMP(tok, ==, ntoks);
1213	ASSERTCMP((char __user *) xdr - buffer, ==, size);
1214	_leave(" = %zu", size);
1215	return size;
1216
1217fault:
1218	_leave(" = -EFAULT");
1219	return -EFAULT;
1220}