1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC key management
3 *
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 *
7 * RxRPC keys should have a description of describing their purpose:
8 * "afs@CAMBRIDGE.REDHAT.COM>
9 */
10
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13 #include <crypto/skcipher.h>
14 #include <linux/module.h>
15 #include <linux/net.h>
16 #include <linux/skbuff.h>
17 #include <linux/key-type.h>
18 #include <linux/ctype.h>
19 #include <linux/slab.h>
20 #include <net/sock.h>
21 #include <net/af_rxrpc.h>
22 #include <keys/rxrpc-type.h>
23 #include <keys/user-type.h>
24 #include "ar-internal.h"
25
26 static int rxrpc_vet_description_s(const char *);
27 static int rxrpc_preparse(struct key_preparsed_payload *);
28 static int rxrpc_preparse_s(struct key_preparsed_payload *);
29 static void rxrpc_free_preparse(struct key_preparsed_payload *);
30 static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
31 static void rxrpc_destroy(struct key *);
32 static void rxrpc_destroy_s(struct key *);
33 static void rxrpc_describe(const struct key *, struct seq_file *);
34 static long rxrpc_read(const struct key *, char *, 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 */
40 struct key_type key_type_rxrpc = {
41 .name = "rxrpc",
42 .flags = KEY_TYPE_NET_DOMAIN,
43 .preparse = rxrpc_preparse,
44 .free_preparse = rxrpc_free_preparse,
45 .instantiate = generic_key_instantiate,
46 .destroy = rxrpc_destroy,
47 .describe = rxrpc_describe,
48 .read = rxrpc_read,
49 };
50 EXPORT_SYMBOL(key_type_rxrpc);
51
52 /*
53 * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
54 * description and an 8-byte decryption key as the payload
55 */
56 struct key_type key_type_rxrpc_s = {
57 .name = "rxrpc_s",
58 .flags = KEY_TYPE_NET_DOMAIN,
59 .vet_description = rxrpc_vet_description_s,
60 .preparse = rxrpc_preparse_s,
61 .free_preparse = rxrpc_free_preparse_s,
62 .instantiate = generic_key_instantiate,
63 .destroy = rxrpc_destroy_s,
64 .describe = rxrpc_describe,
65 };
66
67 /*
68 * Vet the description for an RxRPC server key
69 */
rxrpc_vet_description_s(const char * desc)70 static int rxrpc_vet_description_s(const char *desc)
71 {
72 unsigned long num;
73 char *p;
74
75 num = simple_strtoul(desc, &p, 10);
76 if (*p != ':' || num > 65535)
77 return -EINVAL;
78 num = simple_strtoul(p + 1, &p, 10);
79 if (*p || num < 1 || num > 255)
80 return -EINVAL;
81 return 0;
82 }
83
84 /*
85 * parse an RxKAD type XDR format token
86 * - the caller guarantees we have at least 4 words
87 */
rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload * prep,size_t datalen,const __be32 * xdr,unsigned int toklen)88 static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
89 size_t datalen,
90 const __be32 *xdr, unsigned int toklen)
91 {
92 struct rxrpc_key_token *token, **pptoken;
93 time64_t expiry;
94 size_t plen;
95 u32 tktlen;
96
97 _enter(",{%x,%x,%x,%x},%u",
98 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
99 toklen);
100
101 if (toklen <= 8 * 4)
102 return -EKEYREJECTED;
103 tktlen = ntohl(xdr[7]);
104 _debug("tktlen: %x", tktlen);
105 if (tktlen > AFSTOKEN_RK_TIX_MAX)
106 return -EKEYREJECTED;
107 if (toklen < 8 * 4 + tktlen)
108 return -EKEYREJECTED;
109
110 plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
111 prep->quotalen = datalen + plen;
112
113 plen -= sizeof(*token);
114 token = kzalloc(sizeof(*token), GFP_KERNEL);
115 if (!token)
116 return -ENOMEM;
117
118 token->kad = kzalloc(plen, GFP_KERNEL);
119 if (!token->kad) {
120 kfree(token);
121 return -ENOMEM;
122 }
123
124 token->security_index = RXRPC_SECURITY_RXKAD;
125 token->kad->ticket_len = tktlen;
126 token->kad->vice_id = ntohl(xdr[0]);
127 token->kad->kvno = ntohl(xdr[1]);
128 token->kad->start = ntohl(xdr[4]);
129 token->kad->expiry = ntohl(xdr[5]);
130 token->kad->primary_flag = ntohl(xdr[6]);
131 memcpy(&token->kad->session_key, &xdr[2], 8);
132 memcpy(&token->kad->ticket, &xdr[8], tktlen);
133
134 _debug("SCIX: %u", token->security_index);
135 _debug("TLEN: %u", token->kad->ticket_len);
136 _debug("EXPY: %x", token->kad->expiry);
137 _debug("KVNO: %u", token->kad->kvno);
138 _debug("PRIM: %u", token->kad->primary_flag);
139 _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
140 token->kad->session_key[0], token->kad->session_key[1],
141 token->kad->session_key[2], token->kad->session_key[3],
142 token->kad->session_key[4], token->kad->session_key[5],
143 token->kad->session_key[6], token->kad->session_key[7]);
144 if (token->kad->ticket_len >= 8)
145 _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
146 token->kad->ticket[0], token->kad->ticket[1],
147 token->kad->ticket[2], token->kad->ticket[3],
148 token->kad->ticket[4], token->kad->ticket[5],
149 token->kad->ticket[6], token->kad->ticket[7]);
150
151 /* count the number of tokens attached */
152 prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
153
154 /* attach the data */
155 for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
156 *pptoken;
157 pptoken = &(*pptoken)->next)
158 continue;
159 *pptoken = token;
160 expiry = rxrpc_u32_to_time64(token->kad->expiry);
161 if (expiry < prep->expiry)
162 prep->expiry = expiry;
163
164 _leave(" = 0");
165 return 0;
166 }
167
rxrpc_free_krb5_principal(struct krb5_principal * princ)168 static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
169 {
170 int loop;
171
172 if (princ->name_parts) {
173 for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
174 kfree(princ->name_parts[loop]);
175 kfree(princ->name_parts);
176 }
177 kfree(princ->realm);
178 }
179
rxrpc_free_krb5_tagged(struct krb5_tagged_data * td)180 static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
181 {
182 kfree(td->data);
183 }
184
185 /*
186 * free up an RxK5 token
187 */
rxrpc_rxk5_free(struct rxk5_key * rxk5)188 static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
189 {
190 int loop;
191
192 rxrpc_free_krb5_principal(&rxk5->client);
193 rxrpc_free_krb5_principal(&rxk5->server);
194 rxrpc_free_krb5_tagged(&rxk5->session);
195
196 if (rxk5->addresses) {
197 for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
198 rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
199 kfree(rxk5->addresses);
200 }
201 if (rxk5->authdata) {
202 for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
203 rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
204 kfree(rxk5->authdata);
205 }
206
207 kfree(rxk5->ticket);
208 kfree(rxk5->ticket2);
209 kfree(rxk5);
210 }
211
212 /*
213 * extract a krb5 principal
214 */
rxrpc_krb5_decode_principal(struct krb5_principal * princ,const __be32 ** _xdr,unsigned int * _toklen)215 static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
216 const __be32 **_xdr,
217 unsigned int *_toklen)
218 {
219 const __be32 *xdr = *_xdr;
220 unsigned int toklen = *_toklen, n_parts, loop, tmp, paddedlen;
221
222 /* there must be at least one name, and at least #names+1 length
223 * words */
224 if (toklen <= 12)
225 return -EINVAL;
226
227 _enter(",{%x,%x,%x},%u",
228 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
229
230 n_parts = ntohl(*xdr++);
231 toklen -= 4;
232 if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
233 return -EINVAL;
234 princ->n_name_parts = n_parts;
235
236 if (toklen <= (n_parts + 1) * 4)
237 return -EINVAL;
238
239 princ->name_parts = kcalloc(n_parts, sizeof(char *), GFP_KERNEL);
240 if (!princ->name_parts)
241 return -ENOMEM;
242
243 for (loop = 0; loop < n_parts; loop++) {
244 if (toklen < 4)
245 return -EINVAL;
246 tmp = ntohl(*xdr++);
247 toklen -= 4;
248 if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
249 return -EINVAL;
250 paddedlen = (tmp + 3) & ~3;
251 if (paddedlen > toklen)
252 return -EINVAL;
253 princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
254 if (!princ->name_parts[loop])
255 return -ENOMEM;
256 memcpy(princ->name_parts[loop], xdr, tmp);
257 princ->name_parts[loop][tmp] = 0;
258 toklen -= paddedlen;
259 xdr += paddedlen >> 2;
260 }
261
262 if (toklen < 4)
263 return -EINVAL;
264 tmp = ntohl(*xdr++);
265 toklen -= 4;
266 if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
267 return -EINVAL;
268 paddedlen = (tmp + 3) & ~3;
269 if (paddedlen > toklen)
270 return -EINVAL;
271 princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
272 if (!princ->realm)
273 return -ENOMEM;
274 memcpy(princ->realm, xdr, tmp);
275 princ->realm[tmp] = 0;
276 toklen -= paddedlen;
277 xdr += paddedlen >> 2;
278
279 _debug("%s/...@%s", princ->name_parts[0], princ->realm);
280
281 *_xdr = xdr;
282 *_toklen = toklen;
283 _leave(" = 0 [toklen=%u]", toklen);
284 return 0;
285 }
286
287 /*
288 * extract a piece of krb5 tagged data
289 */
rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data * td,size_t max_data_size,const __be32 ** _xdr,unsigned int * _toklen)290 static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
291 size_t max_data_size,
292 const __be32 **_xdr,
293 unsigned int *_toklen)
294 {
295 const __be32 *xdr = *_xdr;
296 unsigned int toklen = *_toklen, len, paddedlen;
297
298 /* there must be at least one tag and one length word */
299 if (toklen <= 8)
300 return -EINVAL;
301
302 _enter(",%zu,{%x,%x},%u",
303 max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
304
305 td->tag = ntohl(*xdr++);
306 len = ntohl(*xdr++);
307 toklen -= 8;
308 if (len > max_data_size)
309 return -EINVAL;
310 paddedlen = (len + 3) & ~3;
311 if (paddedlen > toklen)
312 return -EINVAL;
313 td->data_len = len;
314
315 if (len > 0) {
316 td->data = kmemdup(xdr, len, GFP_KERNEL);
317 if (!td->data)
318 return -ENOMEM;
319 toklen -= paddedlen;
320 xdr += paddedlen >> 2;
321 }
322
323 _debug("tag %x len %x", td->tag, td->data_len);
324
325 *_xdr = xdr;
326 *_toklen = toklen;
327 _leave(" = 0 [toklen=%u]", toklen);
328 return 0;
329 }
330
331 /*
332 * extract an array of tagged data
333 */
rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data ** _td,u8 * _n_elem,u8 max_n_elem,size_t max_elem_size,const __be32 ** _xdr,unsigned int * _toklen)334 static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
335 u8 *_n_elem,
336 u8 max_n_elem,
337 size_t max_elem_size,
338 const __be32 **_xdr,
339 unsigned int *_toklen)
340 {
341 struct krb5_tagged_data *td;
342 const __be32 *xdr = *_xdr;
343 unsigned int toklen = *_toklen, n_elem, loop;
344 int ret;
345
346 /* there must be at least one count */
347 if (toklen < 4)
348 return -EINVAL;
349
350 _enter(",,%u,%zu,{%x},%u",
351 max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
352
353 n_elem = ntohl(*xdr++);
354 toklen -= 4;
355 if (n_elem > max_n_elem)
356 return -EINVAL;
357 *_n_elem = n_elem;
358 if (n_elem > 0) {
359 if (toklen <= (n_elem + 1) * 4)
360 return -EINVAL;
361
362 _debug("n_elem %d", n_elem);
363
364 td = kcalloc(n_elem, sizeof(struct krb5_tagged_data),
365 GFP_KERNEL);
366 if (!td)
367 return -ENOMEM;
368 *_td = td;
369
370 for (loop = 0; loop < n_elem; loop++) {
371 ret = rxrpc_krb5_decode_tagged_data(&td[loop],
372 max_elem_size,
373 &xdr, &toklen);
374 if (ret < 0)
375 return ret;
376 }
377 }
378
379 *_xdr = xdr;
380 *_toklen = toklen;
381 _leave(" = 0 [toklen=%u]", toklen);
382 return 0;
383 }
384
385 /*
386 * extract a krb5 ticket
387 */
rxrpc_krb5_decode_ticket(u8 ** _ticket,u16 * _tktlen,const __be32 ** _xdr,unsigned int * _toklen)388 static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
389 const __be32 **_xdr, unsigned int *_toklen)
390 {
391 const __be32 *xdr = *_xdr;
392 unsigned int toklen = *_toklen, len, paddedlen;
393
394 /* there must be at least one length word */
395 if (toklen <= 4)
396 return -EINVAL;
397
398 _enter(",{%x},%u", ntohl(xdr[0]), toklen);
399
400 len = ntohl(*xdr++);
401 toklen -= 4;
402 if (len > AFSTOKEN_K5_TIX_MAX)
403 return -EINVAL;
404 paddedlen = (len + 3) & ~3;
405 if (paddedlen > toklen)
406 return -EINVAL;
407 *_tktlen = len;
408
409 _debug("ticket len %u", len);
410
411 if (len > 0) {
412 *_ticket = kmemdup(xdr, len, GFP_KERNEL);
413 if (!*_ticket)
414 return -ENOMEM;
415 toklen -= paddedlen;
416 xdr += paddedlen >> 2;
417 }
418
419 *_xdr = xdr;
420 *_toklen = toklen;
421 _leave(" = 0 [toklen=%u]", toklen);
422 return 0;
423 }
424
425 /*
426 * parse an RxK5 type XDR format token
427 * - the caller guarantees we have at least 4 words
428 */
rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload * prep,size_t datalen,const __be32 * xdr,unsigned int toklen)429 static int rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
430 size_t datalen,
431 const __be32 *xdr, unsigned int toklen)
432 {
433 struct rxrpc_key_token *token, **pptoken;
434 struct rxk5_key *rxk5;
435 const __be32 *end_xdr = xdr + (toklen >> 2);
436 time64_t expiry;
437 int ret;
438
439 _enter(",{%x,%x,%x,%x},%u",
440 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
441 toklen);
442
443 /* reserve some payload space for this subkey - the length of the token
444 * is a reasonable approximation */
445 prep->quotalen = datalen + toklen;
446
447 token = kzalloc(sizeof(*token), GFP_KERNEL);
448 if (!token)
449 return -ENOMEM;
450
451 rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
452 if (!rxk5) {
453 kfree(token);
454 return -ENOMEM;
455 }
456
457 token->security_index = RXRPC_SECURITY_RXK5;
458 token->k5 = rxk5;
459
460 /* extract the principals */
461 ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
462 if (ret < 0)
463 goto error;
464 ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
465 if (ret < 0)
466 goto error;
467
468 /* extract the session key and the encoding type (the tag field ->
469 * ENCTYPE_xxx) */
470 ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
471 &xdr, &toklen);
472 if (ret < 0)
473 goto error;
474
475 if (toklen < 4 * 8 + 2 * 4)
476 goto inval;
477 rxk5->authtime = be64_to_cpup((const __be64 *) xdr);
478 xdr += 2;
479 rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
480 xdr += 2;
481 rxk5->endtime = be64_to_cpup((const __be64 *) xdr);
482 xdr += 2;
483 rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
484 xdr += 2;
485 rxk5->is_skey = ntohl(*xdr++);
486 rxk5->flags = ntohl(*xdr++);
487 toklen -= 4 * 8 + 2 * 4;
488
489 _debug("times: a=%llx s=%llx e=%llx rt=%llx",
490 rxk5->authtime, rxk5->starttime, rxk5->endtime,
491 rxk5->renew_till);
492 _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
493
494 /* extract the permitted client addresses */
495 ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
496 &rxk5->n_addresses,
497 AFSTOKEN_K5_ADDRESSES_MAX,
498 AFSTOKEN_DATA_MAX,
499 &xdr, &toklen);
500 if (ret < 0)
501 goto error;
502
503 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
504
505 /* extract the tickets */
506 ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
507 &xdr, &toklen);
508 if (ret < 0)
509 goto error;
510 ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
511 &xdr, &toklen);
512 if (ret < 0)
513 goto error;
514
515 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
516
517 /* extract the typed auth data */
518 ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
519 &rxk5->n_authdata,
520 AFSTOKEN_K5_AUTHDATA_MAX,
521 AFSTOKEN_BDATALN_MAX,
522 &xdr, &toklen);
523 if (ret < 0)
524 goto error;
525
526 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
527
528 if (toklen != 0)
529 goto inval;
530
531 /* attach the payload */
532 for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
533 *pptoken;
534 pptoken = &(*pptoken)->next)
535 continue;
536 *pptoken = token;
537 expiry = rxrpc_u32_to_time64(token->k5->endtime);
538 if (expiry < prep->expiry)
539 prep->expiry = expiry;
540
541 _leave(" = 0");
542 return 0;
543
544 inval:
545 ret = -EINVAL;
546 error:
547 rxrpc_rxk5_free(rxk5);
548 kfree(token);
549 _leave(" = %d", ret);
550 return ret;
551 }
552
553 /*
554 * attempt to parse the data as the XDR format
555 * - the caller guarantees we have more than 7 words
556 */
rxrpc_preparse_xdr(struct key_preparsed_payload * prep)557 static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
558 {
559 const __be32 *xdr = prep->data, *token;
560 const char *cp;
561 unsigned int len, paddedlen, loop, ntoken, toklen, sec_ix;
562 size_t datalen = prep->datalen;
563 int ret;
564
565 _enter(",{%x,%x,%x,%x},%zu",
566 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
567 prep->datalen);
568
569 if (datalen > AFSTOKEN_LENGTH_MAX)
570 goto not_xdr;
571
572 /* XDR is an array of __be32's */
573 if (datalen & 3)
574 goto not_xdr;
575
576 /* the flags should be 0 (the setpag bit must be handled by
577 * userspace) */
578 if (ntohl(*xdr++) != 0)
579 goto not_xdr;
580 datalen -= 4;
581
582 /* check the cell name */
583 len = ntohl(*xdr++);
584 if (len < 1 || len > AFSTOKEN_CELL_MAX)
585 goto not_xdr;
586 datalen -= 4;
587 paddedlen = (len + 3) & ~3;
588 if (paddedlen > datalen)
589 goto not_xdr;
590
591 cp = (const char *) xdr;
592 for (loop = 0; loop < len; loop++)
593 if (!isprint(cp[loop]))
594 goto not_xdr;
595 for (; loop < paddedlen; loop++)
596 if (cp[loop])
597 goto not_xdr;
598 _debug("cellname: [%u/%u] '%*.*s'",
599 len, paddedlen, len, len, (const char *) xdr);
600 datalen -= paddedlen;
601 xdr += paddedlen >> 2;
602
603 /* get the token count */
604 if (datalen < 12)
605 goto not_xdr;
606 ntoken = ntohl(*xdr++);
607 datalen -= 4;
608 _debug("ntoken: %x", ntoken);
609 if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
610 goto not_xdr;
611
612 /* check each token wrapper */
613 token = xdr;
614 loop = ntoken;
615 do {
616 if (datalen < 8)
617 goto not_xdr;
618 toklen = ntohl(*xdr++);
619 sec_ix = ntohl(*xdr);
620 datalen -= 4;
621 _debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
622 paddedlen = (toklen + 3) & ~3;
623 if (toklen < 20 || toklen > datalen || paddedlen > datalen)
624 goto not_xdr;
625 datalen -= paddedlen;
626 xdr += paddedlen >> 2;
627
628 } while (--loop > 0);
629
630 _debug("remainder: %zu", datalen);
631 if (datalen != 0)
632 goto not_xdr;
633
634 /* okay: we're going to assume it's valid XDR format
635 * - we ignore the cellname, relying on the key to be correctly named
636 */
637 do {
638 xdr = token;
639 toklen = ntohl(*xdr++);
640 token = xdr + ((toklen + 3) >> 2);
641 sec_ix = ntohl(*xdr++);
642 toklen -= 4;
643
644 _debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
645
646 switch (sec_ix) {
647 case RXRPC_SECURITY_RXKAD:
648 ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
649 if (ret != 0)
650 goto error;
651 break;
652
653 case RXRPC_SECURITY_RXK5:
654 ret = rxrpc_preparse_xdr_rxk5(prep, datalen, xdr, toklen);
655 if (ret != 0)
656 goto error;
657 break;
658
659 default:
660 ret = -EPROTONOSUPPORT;
661 goto error;
662 }
663
664 } while (--ntoken > 0);
665
666 _leave(" = 0");
667 return 0;
668
669 not_xdr:
670 _leave(" = -EPROTO");
671 return -EPROTO;
672 error:
673 _leave(" = %d", ret);
674 return ret;
675 }
676
677 /*
678 * Preparse an rxrpc defined key.
679 *
680 * Data should be of the form:
681 * OFFSET LEN CONTENT
682 * 0 4 key interface version number
683 * 4 2 security index (type)
684 * 6 2 ticket length
685 * 8 4 key expiry time (time_t)
686 * 12 4 kvno
687 * 16 8 session key
688 * 24 [len] ticket
689 *
690 * if no data is provided, then a no-security key is made
691 */
rxrpc_preparse(struct key_preparsed_payload * prep)692 static int rxrpc_preparse(struct key_preparsed_payload *prep)
693 {
694 const struct rxrpc_key_data_v1 *v1;
695 struct rxrpc_key_token *token, **pp;
696 time64_t expiry;
697 size_t plen;
698 u32 kver;
699 int ret;
700
701 _enter("%zu", prep->datalen);
702
703 /* handle a no-security key */
704 if (!prep->data && prep->datalen == 0)
705 return 0;
706
707 /* determine if the XDR payload format is being used */
708 if (prep->datalen > 7 * 4) {
709 ret = rxrpc_preparse_xdr(prep);
710 if (ret != -EPROTO)
711 return ret;
712 }
713
714 /* get the key interface version number */
715 ret = -EINVAL;
716 if (prep->datalen <= 4 || !prep->data)
717 goto error;
718 memcpy(&kver, prep->data, sizeof(kver));
719 prep->data += sizeof(kver);
720 prep->datalen -= sizeof(kver);
721
722 _debug("KEY I/F VERSION: %u", kver);
723
724 ret = -EKEYREJECTED;
725 if (kver != 1)
726 goto error;
727
728 /* deal with a version 1 key */
729 ret = -EINVAL;
730 if (prep->datalen < sizeof(*v1))
731 goto error;
732
733 v1 = prep->data;
734 if (prep->datalen != sizeof(*v1) + v1->ticket_length)
735 goto error;
736
737 _debug("SCIX: %u", v1->security_index);
738 _debug("TLEN: %u", v1->ticket_length);
739 _debug("EXPY: %x", v1->expiry);
740 _debug("KVNO: %u", v1->kvno);
741 _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
742 v1->session_key[0], v1->session_key[1],
743 v1->session_key[2], v1->session_key[3],
744 v1->session_key[4], v1->session_key[5],
745 v1->session_key[6], v1->session_key[7]);
746 if (v1->ticket_length >= 8)
747 _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
748 v1->ticket[0], v1->ticket[1],
749 v1->ticket[2], v1->ticket[3],
750 v1->ticket[4], v1->ticket[5],
751 v1->ticket[6], v1->ticket[7]);
752
753 ret = -EPROTONOSUPPORT;
754 if (v1->security_index != RXRPC_SECURITY_RXKAD)
755 goto error;
756
757 plen = sizeof(*token->kad) + v1->ticket_length;
758 prep->quotalen = plen + sizeof(*token);
759
760 ret = -ENOMEM;
761 token = kzalloc(sizeof(*token), GFP_KERNEL);
762 if (!token)
763 goto error;
764 token->kad = kzalloc(plen, GFP_KERNEL);
765 if (!token->kad)
766 goto error_free;
767
768 token->security_index = RXRPC_SECURITY_RXKAD;
769 token->kad->ticket_len = v1->ticket_length;
770 token->kad->expiry = v1->expiry;
771 token->kad->kvno = v1->kvno;
772 memcpy(&token->kad->session_key, &v1->session_key, 8);
773 memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
774
775 /* count the number of tokens attached */
776 prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
777
778 /* attach the data */
779 pp = (struct rxrpc_key_token **)&prep->payload.data[0];
780 while (*pp)
781 pp = &(*pp)->next;
782 *pp = token;
783 expiry = rxrpc_u32_to_time64(token->kad->expiry);
784 if (expiry < prep->expiry)
785 prep->expiry = expiry;
786 token = NULL;
787 ret = 0;
788
789 error_free:
790 kfree(token);
791 error:
792 return ret;
793 }
794
795 /*
796 * Free token list.
797 */
rxrpc_free_token_list(struct rxrpc_key_token * token)798 static void rxrpc_free_token_list(struct rxrpc_key_token *token)
799 {
800 struct rxrpc_key_token *next;
801
802 for (; token; token = next) {
803 next = token->next;
804 switch (token->security_index) {
805 case RXRPC_SECURITY_RXKAD:
806 kfree(token->kad);
807 break;
808 case RXRPC_SECURITY_RXK5:
809 if (token->k5)
810 rxrpc_rxk5_free(token->k5);
811 break;
812 default:
813 pr_err("Unknown token type %x on rxrpc key\n",
814 token->security_index);
815 BUG();
816 }
817
818 kfree(token);
819 }
820 }
821
822 /*
823 * Clean up preparse data.
824 */
rxrpc_free_preparse(struct key_preparsed_payload * prep)825 static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
826 {
827 rxrpc_free_token_list(prep->payload.data[0]);
828 }
829
830 /*
831 * Preparse a server secret key.
832 *
833 * The data should be the 8-byte secret key.
834 */
rxrpc_preparse_s(struct key_preparsed_payload * prep)835 static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
836 {
837 struct crypto_skcipher *ci;
838
839 _enter("%zu", prep->datalen);
840
841 if (prep->datalen != 8)
842 return -EINVAL;
843
844 memcpy(&prep->payload.data[2], prep->data, 8);
845
846 ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
847 if (IS_ERR(ci)) {
848 _leave(" = %ld", PTR_ERR(ci));
849 return PTR_ERR(ci);
850 }
851
852 if (crypto_skcipher_setkey(ci, prep->data, 8) < 0)
853 BUG();
854
855 prep->payload.data[0] = ci;
856 _leave(" = 0");
857 return 0;
858 }
859
860 /*
861 * Clean up preparse data.
862 */
rxrpc_free_preparse_s(struct key_preparsed_payload * prep)863 static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
864 {
865 if (prep->payload.data[0])
866 crypto_free_skcipher(prep->payload.data[0]);
867 }
868
869 /*
870 * dispose of the data dangling from the corpse of a rxrpc key
871 */
rxrpc_destroy(struct key * key)872 static void rxrpc_destroy(struct key *key)
873 {
874 rxrpc_free_token_list(key->payload.data[0]);
875 }
876
877 /*
878 * dispose of the data dangling from the corpse of a rxrpc key
879 */
rxrpc_destroy_s(struct key * key)880 static void rxrpc_destroy_s(struct key *key)
881 {
882 if (key->payload.data[0]) {
883 crypto_free_skcipher(key->payload.data[0]);
884 key->payload.data[0] = NULL;
885 }
886 }
887
888 /*
889 * describe the rxrpc key
890 */
rxrpc_describe(const struct key * key,struct seq_file * m)891 static void rxrpc_describe(const struct key *key, struct seq_file *m)
892 {
893 seq_puts(m, key->description);
894 }
895
896 /*
897 * grab the security key for a socket
898 */
rxrpc_request_key(struct rxrpc_sock * rx,sockptr_t optval,int optlen)899 int rxrpc_request_key(struct rxrpc_sock *rx, sockptr_t optval, int optlen)
900 {
901 struct key *key;
902 char *description;
903
904 _enter("");
905
906 if (optlen <= 0 || optlen > PAGE_SIZE - 1 || rx->securities)
907 return -EINVAL;
908
909 description = memdup_sockptr_nul(optval, optlen);
910 if (IS_ERR(description))
911 return PTR_ERR(description);
912
913 key = request_key_net(&key_type_rxrpc, description, sock_net(&rx->sk), NULL);
914 if (IS_ERR(key)) {
915 kfree(description);
916 _leave(" = %ld", PTR_ERR(key));
917 return PTR_ERR(key);
918 }
919
920 rx->key = key;
921 kfree(description);
922 _leave(" = 0 [key %x]", key->serial);
923 return 0;
924 }
925
926 /*
927 * grab the security keyring for a server socket
928 */
rxrpc_server_keyring(struct rxrpc_sock * rx,sockptr_t optval,int optlen)929 int rxrpc_server_keyring(struct rxrpc_sock *rx, sockptr_t optval, int optlen)
930 {
931 struct key *key;
932 char *description;
933
934 _enter("");
935
936 if (optlen <= 0 || optlen > PAGE_SIZE - 1)
937 return -EINVAL;
938
939 description = memdup_sockptr_nul(optval, optlen);
940 if (IS_ERR(description))
941 return PTR_ERR(description);
942
943 key = request_key(&key_type_keyring, description, NULL);
944 if (IS_ERR(key)) {
945 kfree(description);
946 _leave(" = %ld", PTR_ERR(key));
947 return PTR_ERR(key);
948 }
949
950 rx->securities = key;
951 kfree(description);
952 _leave(" = 0 [key %x]", key->serial);
953 return 0;
954 }
955
956 /*
957 * generate a server data key
958 */
rxrpc_get_server_data_key(struct rxrpc_connection * conn,const void * session_key,time64_t expiry,u32 kvno)959 int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
960 const void *session_key,
961 time64_t expiry,
962 u32 kvno)
963 {
964 const struct cred *cred = current_cred();
965 struct key *key;
966 int ret;
967
968 struct {
969 u32 kver;
970 struct rxrpc_key_data_v1 v1;
971 } data;
972
973 _enter("");
974
975 key = key_alloc(&key_type_rxrpc, "x",
976 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
977 KEY_ALLOC_NOT_IN_QUOTA, NULL);
978 if (IS_ERR(key)) {
979 _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
980 return -ENOMEM;
981 }
982
983 _debug("key %d", key_serial(key));
984
985 data.kver = 1;
986 data.v1.security_index = RXRPC_SECURITY_RXKAD;
987 data.v1.ticket_length = 0;
988 data.v1.expiry = rxrpc_time64_to_u32(expiry);
989 data.v1.kvno = 0;
990
991 memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
992
993 ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
994 if (ret < 0)
995 goto error;
996
997 conn->params.key = key;
998 _leave(" = 0 [%d]", key_serial(key));
999 return 0;
1000
1001 error:
1002 key_revoke(key);
1003 key_put(key);
1004 _leave(" = -ENOMEM [ins %d]", ret);
1005 return -ENOMEM;
1006 }
1007 EXPORT_SYMBOL(rxrpc_get_server_data_key);
1008
1009 /**
1010 * rxrpc_get_null_key - Generate a null RxRPC key
1011 * @keyname: The name to give the key.
1012 *
1013 * Generate a null RxRPC key that can be used to indicate anonymous security is
1014 * required for a particular domain.
1015 */
rxrpc_get_null_key(const char * keyname)1016 struct key *rxrpc_get_null_key(const char *keyname)
1017 {
1018 const struct cred *cred = current_cred();
1019 struct key *key;
1020 int ret;
1021
1022 key = key_alloc(&key_type_rxrpc, keyname,
1023 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
1024 KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL);
1025 if (IS_ERR(key))
1026 return key;
1027
1028 ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
1029 if (ret < 0) {
1030 key_revoke(key);
1031 key_put(key);
1032 return ERR_PTR(ret);
1033 }
1034
1035 return key;
1036 }
1037 EXPORT_SYMBOL(rxrpc_get_null_key);
1038
1039 /*
1040 * read the contents of an rxrpc key
1041 * - this returns the result in XDR form
1042 */
rxrpc_read(const struct key * key,char * buffer,size_t buflen)1043 static long rxrpc_read(const struct key *key,
1044 char *buffer, size_t buflen)
1045 {
1046 const struct rxrpc_key_token *token;
1047 const struct krb5_principal *princ;
1048 size_t size;
1049 __be32 *xdr, *oldxdr;
1050 u32 cnlen, toksize, ntoks, tok, zero;
1051 u16 toksizes[AFSTOKEN_MAX];
1052 int loop;
1053
1054 _enter("");
1055
1056 /* we don't know what form we should return non-AFS keys in */
1057 if (memcmp(key->description, "afs@", 4) != 0)
1058 return -EOPNOTSUPP;
1059 cnlen = strlen(key->description + 4);
1060
1061 #define RND(X) (((X) + 3) & ~3)
1062
1063 /* AFS keys we return in XDR form, so we need to work out the size of
1064 * the XDR */
1065 size = 2 * 4; /* flags, cellname len */
1066 size += RND(cnlen); /* cellname */
1067 size += 1 * 4; /* token count */
1068
1069 ntoks = 0;
1070 for (token = key->payload.data[0]; token; token = token->next) {
1071 toksize = 4; /* sec index */
1072
1073 switch (token->security_index) {
1074 case RXRPC_SECURITY_RXKAD:
1075 toksize += 8 * 4; /* viceid, kvno, key*2, begin,
1076 * end, primary, tktlen */
1077 toksize += RND(token->kad->ticket_len);
1078 break;
1079
1080 case RXRPC_SECURITY_RXK5:
1081 princ = &token->k5->client;
1082 toksize += 4 + princ->n_name_parts * 4;
1083 for (loop = 0; loop < princ->n_name_parts; loop++)
1084 toksize += RND(strlen(princ->name_parts[loop]));
1085 toksize += 4 + RND(strlen(princ->realm));
1086
1087 princ = &token->k5->server;
1088 toksize += 4 + princ->n_name_parts * 4;
1089 for (loop = 0; loop < princ->n_name_parts; loop++)
1090 toksize += RND(strlen(princ->name_parts[loop]));
1091 toksize += 4 + RND(strlen(princ->realm));
1092
1093 toksize += 8 + RND(token->k5->session.data_len);
1094
1095 toksize += 4 * 8 + 2 * 4;
1096
1097 toksize += 4 + token->k5->n_addresses * 8;
1098 for (loop = 0; loop < token->k5->n_addresses; loop++)
1099 toksize += RND(token->k5->addresses[loop].data_len);
1100
1101 toksize += 4 + RND(token->k5->ticket_len);
1102 toksize += 4 + RND(token->k5->ticket2_len);
1103
1104 toksize += 4 + token->k5->n_authdata * 8;
1105 for (loop = 0; loop < token->k5->n_authdata; loop++)
1106 toksize += RND(token->k5->authdata[loop].data_len);
1107 break;
1108
1109 default: /* we have a ticket we can't encode */
1110 pr_err("Unsupported key token type (%u)\n",
1111 token->security_index);
1112 continue;
1113 }
1114
1115 _debug("token[%u]: toksize=%u", ntoks, toksize);
1116 ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
1117
1118 toksizes[ntoks++] = toksize;
1119 size += toksize + 4; /* each token has a length word */
1120 }
1121
1122 #undef RND
1123
1124 if (!buffer || buflen < size)
1125 return size;
1126
1127 xdr = (__be32 *)buffer;
1128 zero = 0;
1129 #define ENCODE(x) \
1130 do { \
1131 *xdr++ = htonl(x); \
1132 } while(0)
1133 #define ENCODE_DATA(l, s) \
1134 do { \
1135 u32 _l = (l); \
1136 ENCODE(l); \
1137 memcpy(xdr, (s), _l); \
1138 if (_l & 3) \
1139 memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3)); \
1140 xdr += (_l + 3) >> 2; \
1141 } while(0)
1142 #define ENCODE_BYTES(l, s) \
1143 do { \
1144 u32 _l = (l); \
1145 memcpy(xdr, (s), _l); \
1146 if (_l & 3) \
1147 memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3)); \
1148 xdr += (_l + 3) >> 2; \
1149 } while(0)
1150 #define ENCODE64(x) \
1151 do { \
1152 __be64 y = cpu_to_be64(x); \
1153 memcpy(xdr, &y, 8); \
1154 xdr += 8 >> 2; \
1155 } while(0)
1156 #define ENCODE_STR(s) \
1157 do { \
1158 const char *_s = (s); \
1159 ENCODE_DATA(strlen(_s), _s); \
1160 } while(0)
1161
1162 ENCODE(0); /* flags */
1163 ENCODE_DATA(cnlen, key->description + 4); /* cellname */
1164 ENCODE(ntoks);
1165
1166 tok = 0;
1167 for (token = key->payload.data[0]; token; token = token->next) {
1168 toksize = toksizes[tok++];
1169 ENCODE(toksize);
1170 oldxdr = xdr;
1171 ENCODE(token->security_index);
1172
1173 switch (token->security_index) {
1174 case RXRPC_SECURITY_RXKAD:
1175 ENCODE(token->kad->vice_id);
1176 ENCODE(token->kad->kvno);
1177 ENCODE_BYTES(8, token->kad->session_key);
1178 ENCODE(token->kad->start);
1179 ENCODE(token->kad->expiry);
1180 ENCODE(token->kad->primary_flag);
1181 ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
1182 break;
1183
1184 case RXRPC_SECURITY_RXK5:
1185 princ = &token->k5->client;
1186 ENCODE(princ->n_name_parts);
1187 for (loop = 0; loop < princ->n_name_parts; loop++)
1188 ENCODE_STR(princ->name_parts[loop]);
1189 ENCODE_STR(princ->realm);
1190
1191 princ = &token->k5->server;
1192 ENCODE(princ->n_name_parts);
1193 for (loop = 0; loop < princ->n_name_parts; loop++)
1194 ENCODE_STR(princ->name_parts[loop]);
1195 ENCODE_STR(princ->realm);
1196
1197 ENCODE(token->k5->session.tag);
1198 ENCODE_DATA(token->k5->session.data_len,
1199 token->k5->session.data);
1200
1201 ENCODE64(token->k5->authtime);
1202 ENCODE64(token->k5->starttime);
1203 ENCODE64(token->k5->endtime);
1204 ENCODE64(token->k5->renew_till);
1205 ENCODE(token->k5->is_skey);
1206 ENCODE(token->k5->flags);
1207
1208 ENCODE(token->k5->n_addresses);
1209 for (loop = 0; loop < token->k5->n_addresses; loop++) {
1210 ENCODE(token->k5->addresses[loop].tag);
1211 ENCODE_DATA(token->k5->addresses[loop].data_len,
1212 token->k5->addresses[loop].data);
1213 }
1214
1215 ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
1216 ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
1217
1218 ENCODE(token->k5->n_authdata);
1219 for (loop = 0; loop < token->k5->n_authdata; loop++) {
1220 ENCODE(token->k5->authdata[loop].tag);
1221 ENCODE_DATA(token->k5->authdata[loop].data_len,
1222 token->k5->authdata[loop].data);
1223 }
1224 break;
1225
1226 default:
1227 break;
1228 }
1229
1230 ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
1231 toksize);
1232 }
1233
1234 #undef ENCODE_STR
1235 #undef ENCODE_DATA
1236 #undef ENCODE64
1237 #undef ENCODE
1238
1239 ASSERTCMP(tok, ==, ntoks);
1240 ASSERTCMP((char __user *) xdr - buffer, ==, size);
1241 _leave(" = %zu", size);
1242 return size;
1243 }
1244
