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
28 static int rxrpc_vet_description_s(const char *);
29 static int rxrpc_instantiate(struct key *, const void *, size_t);
30 static int rxrpc_instantiate_s(struct key *, const void *, size_t);
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 __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 */
40 struct 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 };
48 EXPORT_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 */
54 struct 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 */
rxrpc_vet_description_s(const char * desc)66 static 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 */
rxrpc_instantiate_xdr_rxkad(struct key * key,const __be32 * xdr,unsigned toklen)84 static 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
rxrpc_free_krb5_principal(struct krb5_principal * princ)164 static 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
rxrpc_free_krb5_tagged(struct krb5_tagged_data * td)176 static 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 */
rxrpc_rxk5_free(struct rxk5_key * rxk5)184 static 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 */
rxrpc_krb5_decode_principal(struct krb5_principal * princ,const __be32 ** _xdr,unsigned * _toklen)211 static 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(n_parts, sizeof(char *), 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 */
rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data * td,size_t max_data_size,const __be32 ** _xdr,unsigned * _toklen)286 static 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 = kmemdup(xdr, len, GFP_KERNEL);
310 if (!td->data)
311 return -ENOMEM;
312 len = (len + 3) & ~3;
313 toklen -= len;
314 xdr += len >> 2;
315 }
316
317 _debug("tag %x len %x", td->tag, td->data_len);
318
319 *_xdr = xdr;
320 *_toklen = toklen;
321 _leave(" = 0 [toklen=%u]", toklen);
322 return 0;
323 }
324
325 /*
326 * extract an array of tagged data
327 */
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 * _toklen)328 static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
329 u8 *_n_elem,
330 u8 max_n_elem,
331 size_t max_elem_size,
332 const __be32 **_xdr,
333 unsigned *_toklen)
334 {
335 struct krb5_tagged_data *td;
336 const __be32 *xdr = *_xdr;
337 unsigned toklen = *_toklen, n_elem, loop;
338 int ret;
339
340 /* there must be at least one count */
341 if (toklen < 4)
342 return -EINVAL;
343
344 _enter(",,%u,%zu,{%x},%u",
345 max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
346
347 n_elem = ntohl(*xdr++);
348 toklen -= 4;
349 if (n_elem < 0 || n_elem > max_n_elem)
350 return -EINVAL;
351 *_n_elem = n_elem;
352 if (n_elem > 0) {
353 if (toklen <= (n_elem + 1) * 4)
354 return -EINVAL;
355
356 _debug("n_elem %d", n_elem);
357
358 td = kcalloc(n_elem, sizeof(struct krb5_tagged_data),
359 GFP_KERNEL);
360 if (!td)
361 return -ENOMEM;
362 *_td = td;
363
364 for (loop = 0; loop < n_elem; loop++) {
365 ret = rxrpc_krb5_decode_tagged_data(&td[loop],
366 max_elem_size,
367 &xdr, &toklen);
368 if (ret < 0)
369 return ret;
370 }
371 }
372
373 *_xdr = xdr;
374 *_toklen = toklen;
375 _leave(" = 0 [toklen=%u]", toklen);
376 return 0;
377 }
378
379 /*
380 * extract a krb5 ticket
381 */
rxrpc_krb5_decode_ticket(u8 ** _ticket,u16 * _tktlen,const __be32 ** _xdr,unsigned * _toklen)382 static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
383 const __be32 **_xdr, unsigned *_toklen)
384 {
385 const __be32 *xdr = *_xdr;
386 unsigned toklen = *_toklen, len;
387
388 /* there must be at least one length word */
389 if (toklen <= 4)
390 return -EINVAL;
391
392 _enter(",{%x},%u", ntohl(xdr[0]), toklen);
393
394 len = ntohl(*xdr++);
395 toklen -= 4;
396 if (len > AFSTOKEN_K5_TIX_MAX)
397 return -EINVAL;
398 *_tktlen = len;
399
400 _debug("ticket len %u", len);
401
402 if (len > 0) {
403 *_ticket = kmemdup(xdr, len, GFP_KERNEL);
404 if (!*_ticket)
405 return -ENOMEM;
406 len = (len + 3) & ~3;
407 toklen -= len;
408 xdr += len >> 2;
409 }
410
411 *_xdr = xdr;
412 *_toklen = toklen;
413 _leave(" = 0 [toklen=%u]", toklen);
414 return 0;
415 }
416
417 /*
418 * parse an RxK5 type XDR format token
419 * - the caller guarantees we have at least 4 words
420 */
rxrpc_instantiate_xdr_rxk5(struct key * key,const __be32 * xdr,unsigned toklen)421 static int rxrpc_instantiate_xdr_rxk5(struct key *key, const __be32 *xdr,
422 unsigned toklen)
423 {
424 struct rxrpc_key_token *token, **pptoken;
425 struct rxk5_key *rxk5;
426 const __be32 *end_xdr = xdr + (toklen >> 2);
427 int ret;
428
429 _enter(",{%x,%x,%x,%x},%u",
430 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
431 toklen);
432
433 /* reserve some payload space for this subkey - the length of the token
434 * is a reasonable approximation */
435 ret = key_payload_reserve(key, key->datalen + toklen);
436 if (ret < 0)
437 return ret;
438
439 token = kzalloc(sizeof(*token), GFP_KERNEL);
440 if (!token)
441 return -ENOMEM;
442
443 rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
444 if (!rxk5) {
445 kfree(token);
446 return -ENOMEM;
447 }
448
449 token->security_index = RXRPC_SECURITY_RXK5;
450 token->k5 = rxk5;
451
452 /* extract the principals */
453 ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
454 if (ret < 0)
455 goto error;
456 ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
457 if (ret < 0)
458 goto error;
459
460 /* extract the session key and the encoding type (the tag field ->
461 * ENCTYPE_xxx) */
462 ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
463 &xdr, &toklen);
464 if (ret < 0)
465 goto error;
466
467 if (toklen < 4 * 8 + 2 * 4)
468 goto inval;
469 rxk5->authtime = be64_to_cpup((const __be64 *) xdr);
470 xdr += 2;
471 rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
472 xdr += 2;
473 rxk5->endtime = be64_to_cpup((const __be64 *) xdr);
474 xdr += 2;
475 rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
476 xdr += 2;
477 rxk5->is_skey = ntohl(*xdr++);
478 rxk5->flags = ntohl(*xdr++);
479 toklen -= 4 * 8 + 2 * 4;
480
481 _debug("times: a=%llx s=%llx e=%llx rt=%llx",
482 rxk5->authtime, rxk5->starttime, rxk5->endtime,
483 rxk5->renew_till);
484 _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
485
486 /* extract the permitted client addresses */
487 ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
488 &rxk5->n_addresses,
489 AFSTOKEN_K5_ADDRESSES_MAX,
490 AFSTOKEN_DATA_MAX,
491 &xdr, &toklen);
492 if (ret < 0)
493 goto error;
494
495 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
496
497 /* extract the tickets */
498 ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
499 &xdr, &toklen);
500 if (ret < 0)
501 goto error;
502 ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
503 &xdr, &toklen);
504 if (ret < 0)
505 goto error;
506
507 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
508
509 /* extract the typed auth data */
510 ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
511 &rxk5->n_authdata,
512 AFSTOKEN_K5_AUTHDATA_MAX,
513 AFSTOKEN_BDATALN_MAX,
514 &xdr, &toklen);
515 if (ret < 0)
516 goto error;
517
518 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
519
520 if (toklen != 0)
521 goto inval;
522
523 /* attach the payload to the key */
524 for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
525 *pptoken;
526 pptoken = &(*pptoken)->next)
527 continue;
528 *pptoken = token;
529 if (token->kad->expiry < key->expiry)
530 key->expiry = token->kad->expiry;
531
532 _leave(" = 0");
533 return 0;
534
535 inval:
536 ret = -EINVAL;
537 error:
538 rxrpc_rxk5_free(rxk5);
539 kfree(token);
540 _leave(" = %d", ret);
541 return ret;
542 }
543
544 /*
545 * attempt to parse the data as the XDR format
546 * - the caller guarantees we have more than 7 words
547 */
rxrpc_instantiate_xdr(struct key * key,const void * data,size_t datalen)548 static int rxrpc_instantiate_xdr(struct key *key, const void *data, size_t datalen)
549 {
550 const __be32 *xdr = data, *token;
551 const char *cp;
552 unsigned len, tmp, loop, ntoken, toklen, sec_ix;
553 int ret;
554
555 _enter(",{%x,%x,%x,%x},%zu",
556 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
557 datalen);
558
559 if (datalen > AFSTOKEN_LENGTH_MAX)
560 goto not_xdr;
561
562 /* XDR is an array of __be32's */
563 if (datalen & 3)
564 goto not_xdr;
565
566 /* the flags should be 0 (the setpag bit must be handled by
567 * userspace) */
568 if (ntohl(*xdr++) != 0)
569 goto not_xdr;
570 datalen -= 4;
571
572 /* check the cell name */
573 len = ntohl(*xdr++);
574 if (len < 1 || len > AFSTOKEN_CELL_MAX)
575 goto not_xdr;
576 datalen -= 4;
577 tmp = (len + 3) & ~3;
578 if (tmp > datalen)
579 goto not_xdr;
580
581 cp = (const char *) xdr;
582 for (loop = 0; loop < len; loop++)
583 if (!isprint(cp[loop]))
584 goto not_xdr;
585 if (len < tmp)
586 for (; loop < tmp; loop++)
587 if (cp[loop])
588 goto not_xdr;
589 _debug("cellname: [%u/%u] '%*.*s'",
590 len, tmp, len, len, (const char *) xdr);
591 datalen -= tmp;
592 xdr += tmp >> 2;
593
594 /* get the token count */
595 if (datalen < 12)
596 goto not_xdr;
597 ntoken = ntohl(*xdr++);
598 datalen -= 4;
599 _debug("ntoken: %x", ntoken);
600 if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
601 goto not_xdr;
602
603 /* check each token wrapper */
604 token = xdr;
605 loop = ntoken;
606 do {
607 if (datalen < 8)
608 goto not_xdr;
609 toklen = ntohl(*xdr++);
610 sec_ix = ntohl(*xdr);
611 datalen -= 4;
612 _debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
613 if (toklen < 20 || toklen > datalen)
614 goto not_xdr;
615 datalen -= (toklen + 3) & ~3;
616 xdr += (toklen + 3) >> 2;
617
618 } while (--loop > 0);
619
620 _debug("remainder: %zu", datalen);
621 if (datalen != 0)
622 goto not_xdr;
623
624 /* okay: we're going to assume it's valid XDR format
625 * - we ignore the cellname, relying on the key to be correctly named
626 */
627 do {
628 xdr = token;
629 toklen = ntohl(*xdr++);
630 token = xdr + ((toklen + 3) >> 2);
631 sec_ix = ntohl(*xdr++);
632 toklen -= 4;
633
634 _debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
635
636 switch (sec_ix) {
637 case RXRPC_SECURITY_RXKAD:
638 ret = rxrpc_instantiate_xdr_rxkad(key, xdr, toklen);
639 if (ret != 0)
640 goto error;
641 break;
642
643 case RXRPC_SECURITY_RXK5:
644 ret = rxrpc_instantiate_xdr_rxk5(key, xdr, toklen);
645 if (ret != 0)
646 goto error;
647 break;
648
649 default:
650 ret = -EPROTONOSUPPORT;
651 goto error;
652 }
653
654 } while (--ntoken > 0);
655
656 _leave(" = 0");
657 return 0;
658
659 not_xdr:
660 _leave(" = -EPROTO");
661 return -EPROTO;
662 error:
663 _leave(" = %d", ret);
664 return ret;
665 }
666
667 /*
668 * instantiate an rxrpc defined key
669 * data should be of the form:
670 * OFFSET LEN CONTENT
671 * 0 4 key interface version number
672 * 4 2 security index (type)
673 * 6 2 ticket length
674 * 8 4 key expiry time (time_t)
675 * 12 4 kvno
676 * 16 8 session key
677 * 24 [len] ticket
678 *
679 * if no data is provided, then a no-security key is made
680 */
rxrpc_instantiate(struct key * key,const void * data,size_t datalen)681 static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen)
682 {
683 const struct rxrpc_key_data_v1 *v1;
684 struct rxrpc_key_token *token, **pp;
685 size_t plen;
686 u32 kver;
687 int ret;
688
689 _enter("{%x},,%zu", key_serial(key), datalen);
690
691 /* handle a no-security key */
692 if (!data && datalen == 0)
693 return 0;
694
695 /* determine if the XDR payload format is being used */
696 if (datalen > 7 * 4) {
697 ret = rxrpc_instantiate_xdr(key, data, datalen);
698 if (ret != -EPROTO)
699 return ret;
700 }
701
702 /* get the key interface version number */
703 ret = -EINVAL;
704 if (datalen <= 4 || !data)
705 goto error;
706 memcpy(&kver, data, sizeof(kver));
707 data += sizeof(kver);
708 datalen -= sizeof(kver);
709
710 _debug("KEY I/F VERSION: %u", kver);
711
712 ret = -EKEYREJECTED;
713 if (kver != 1)
714 goto error;
715
716 /* deal with a version 1 key */
717 ret = -EINVAL;
718 if (datalen < sizeof(*v1))
719 goto error;
720
721 v1 = data;
722 if (datalen != sizeof(*v1) + v1->ticket_length)
723 goto error;
724
725 _debug("SCIX: %u", v1->security_index);
726 _debug("TLEN: %u", v1->ticket_length);
727 _debug("EXPY: %x", v1->expiry);
728 _debug("KVNO: %u", v1->kvno);
729 _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
730 v1->session_key[0], v1->session_key[1],
731 v1->session_key[2], v1->session_key[3],
732 v1->session_key[4], v1->session_key[5],
733 v1->session_key[6], v1->session_key[7]);
734 if (v1->ticket_length >= 8)
735 _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
736 v1->ticket[0], v1->ticket[1],
737 v1->ticket[2], v1->ticket[3],
738 v1->ticket[4], v1->ticket[5],
739 v1->ticket[6], v1->ticket[7]);
740
741 ret = -EPROTONOSUPPORT;
742 if (v1->security_index != RXRPC_SECURITY_RXKAD)
743 goto error;
744
745 plen = sizeof(*token->kad) + v1->ticket_length;
746 ret = key_payload_reserve(key, plen + sizeof(*token));
747 if (ret < 0)
748 goto error;
749
750 ret = -ENOMEM;
751 token = kzalloc(sizeof(*token), GFP_KERNEL);
752 if (!token)
753 goto error;
754 token->kad = kzalloc(plen, GFP_KERNEL);
755 if (!token->kad)
756 goto error_free;
757
758 token->security_index = RXRPC_SECURITY_RXKAD;
759 token->kad->ticket_len = v1->ticket_length;
760 token->kad->expiry = v1->expiry;
761 token->kad->kvno = v1->kvno;
762 memcpy(&token->kad->session_key, &v1->session_key, 8);
763 memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
764
765 /* attach the data */
766 key->type_data.x[0]++;
767
768 pp = (struct rxrpc_key_token **)&key->payload.data;
769 while (*pp)
770 pp = &(*pp)->next;
771 *pp = token;
772 if (token->kad->expiry < key->expiry)
773 key->expiry = token->kad->expiry;
774 token = NULL;
775 ret = 0;
776
777 error_free:
778 kfree(token);
779 error:
780 return ret;
781 }
782
783 /*
784 * instantiate a server secret key
785 * data should be a pointer to the 8-byte secret key
786 */
rxrpc_instantiate_s(struct key * key,const void * data,size_t datalen)787 static int rxrpc_instantiate_s(struct key *key, const void *data,
788 size_t datalen)
789 {
790 struct crypto_blkcipher *ci;
791
792 _enter("{%x},,%zu", key_serial(key), datalen);
793
794 if (datalen != 8)
795 return -EINVAL;
796
797 memcpy(&key->type_data, data, 8);
798
799 ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
800 if (IS_ERR(ci)) {
801 _leave(" = %ld", PTR_ERR(ci));
802 return PTR_ERR(ci);
803 }
804
805 if (crypto_blkcipher_setkey(ci, data, 8) < 0)
806 BUG();
807
808 key->payload.data = ci;
809 _leave(" = 0");
810 return 0;
811 }
812
813 /*
814 * dispose of the data dangling from the corpse of a rxrpc key
815 */
rxrpc_destroy(struct key * key)816 static void rxrpc_destroy(struct key *key)
817 {
818 struct rxrpc_key_token *token;
819
820 while ((token = key->payload.data)) {
821 key->payload.data = token->next;
822 switch (token->security_index) {
823 case RXRPC_SECURITY_RXKAD:
824 kfree(token->kad);
825 break;
826 case RXRPC_SECURITY_RXK5:
827 if (token->k5)
828 rxrpc_rxk5_free(token->k5);
829 break;
830 default:
831 printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
832 token->security_index);
833 BUG();
834 }
835
836 kfree(token);
837 }
838 }
839
840 /*
841 * dispose of the data dangling from the corpse of a rxrpc key
842 */
rxrpc_destroy_s(struct key * key)843 static void rxrpc_destroy_s(struct key *key)
844 {
845 if (key->payload.data) {
846 crypto_free_blkcipher(key->payload.data);
847 key->payload.data = NULL;
848 }
849 }
850
851 /*
852 * describe the rxrpc key
853 */
rxrpc_describe(const struct key * key,struct seq_file * m)854 static void rxrpc_describe(const struct key *key, struct seq_file *m)
855 {
856 seq_puts(m, key->description);
857 }
858
859 /*
860 * grab the security key for a socket
861 */
rxrpc_request_key(struct rxrpc_sock * rx,char __user * optval,int optlen)862 int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
863 {
864 struct key *key;
865 char *description;
866
867 _enter("");
868
869 if (optlen <= 0 || optlen > PAGE_SIZE - 1)
870 return -EINVAL;
871
872 description = kmalloc(optlen + 1, GFP_KERNEL);
873 if (!description)
874 return -ENOMEM;
875
876 if (copy_from_user(description, optval, optlen)) {
877 kfree(description);
878 return -EFAULT;
879 }
880 description[optlen] = 0;
881
882 key = request_key(&key_type_rxrpc, description, NULL);
883 if (IS_ERR(key)) {
884 kfree(description);
885 _leave(" = %ld", PTR_ERR(key));
886 return PTR_ERR(key);
887 }
888
889 rx->key = key;
890 kfree(description);
891 _leave(" = 0 [key %x]", key->serial);
892 return 0;
893 }
894
895 /*
896 * grab the security keyring for a server socket
897 */
rxrpc_server_keyring(struct rxrpc_sock * rx,char __user * optval,int optlen)898 int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
899 int optlen)
900 {
901 struct key *key;
902 char *description;
903
904 _enter("");
905
906 if (optlen <= 0 || optlen > PAGE_SIZE - 1)
907 return -EINVAL;
908
909 description = kmalloc(optlen + 1, GFP_KERNEL);
910 if (!description)
911 return -ENOMEM;
912
913 if (copy_from_user(description, optval, optlen)) {
914 kfree(description);
915 return -EFAULT;
916 }
917 description[optlen] = 0;
918
919 key = request_key(&key_type_keyring, description, NULL);
920 if (IS_ERR(key)) {
921 kfree(description);
922 _leave(" = %ld", PTR_ERR(key));
923 return PTR_ERR(key);
924 }
925
926 rx->securities = key;
927 kfree(description);
928 _leave(" = 0 [key %x]", key->serial);
929 return 0;
930 }
931
932 /*
933 * generate a server data key
934 */
rxrpc_get_server_data_key(struct rxrpc_connection * conn,const void * session_key,time_t expiry,u32 kvno)935 int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
936 const void *session_key,
937 time_t expiry,
938 u32 kvno)
939 {
940 const struct cred *cred = current_cred();
941 struct key *key;
942 int ret;
943
944 struct {
945 u32 kver;
946 struct rxrpc_key_data_v1 v1;
947 } data;
948
949 _enter("");
950
951 key = key_alloc(&key_type_rxrpc, "x", 0, 0, cred, 0,
952 KEY_ALLOC_NOT_IN_QUOTA);
953 if (IS_ERR(key)) {
954 _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
955 return -ENOMEM;
956 }
957
958 _debug("key %d", key_serial(key));
959
960 data.kver = 1;
961 data.v1.security_index = RXRPC_SECURITY_RXKAD;
962 data.v1.ticket_length = 0;
963 data.v1.expiry = expiry;
964 data.v1.kvno = 0;
965
966 memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
967
968 ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
969 if (ret < 0)
970 goto error;
971
972 conn->key = key;
973 _leave(" = 0 [%d]", key_serial(key));
974 return 0;
975
976 error:
977 key_revoke(key);
978 key_put(key);
979 _leave(" = -ENOMEM [ins %d]", ret);
980 return -ENOMEM;
981 }
982 EXPORT_SYMBOL(rxrpc_get_server_data_key);
983
984 /**
985 * rxrpc_get_null_key - Generate a null RxRPC key
986 * @keyname: The name to give the key.
987 *
988 * Generate a null RxRPC key that can be used to indicate anonymous security is
989 * required for a particular domain.
990 */
rxrpc_get_null_key(const char * keyname)991 struct key *rxrpc_get_null_key(const char *keyname)
992 {
993 const struct cred *cred = current_cred();
994 struct key *key;
995 int ret;
996
997 key = key_alloc(&key_type_rxrpc, keyname, 0, 0, cred,
998 KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
999 if (IS_ERR(key))
1000 return key;
1001
1002 ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
1003 if (ret < 0) {
1004 key_revoke(key);
1005 key_put(key);
1006 return ERR_PTR(ret);
1007 }
1008
1009 return key;
1010 }
1011 EXPORT_SYMBOL(rxrpc_get_null_key);
1012
1013 /*
1014 * read the contents of an rxrpc key
1015 * - this returns the result in XDR form
1016 */
rxrpc_read(const struct key * key,char __user * buffer,size_t buflen)1017 static long rxrpc_read(const struct key *key,
1018 char __user *buffer, size_t buflen)
1019 {
1020 const struct rxrpc_key_token *token;
1021 const struct krb5_principal *princ;
1022 size_t size;
1023 __be32 __user *xdr, *oldxdr;
1024 u32 cnlen, toksize, ntoks, tok, zero;
1025 u16 toksizes[AFSTOKEN_MAX];
1026 int loop;
1027
1028 _enter("");
1029
1030 /* we don't know what form we should return non-AFS keys in */
1031 if (memcmp(key->description, "afs@", 4) != 0)
1032 return -EOPNOTSUPP;
1033 cnlen = strlen(key->description + 4);
1034
1035 #define RND(X) (((X) + 3) & ~3)
1036
1037 /* AFS keys we return in XDR form, so we need to work out the size of
1038 * the XDR */
1039 size = 2 * 4; /* flags, cellname len */
1040 size += RND(cnlen); /* cellname */
1041 size += 1 * 4; /* token count */
1042
1043 ntoks = 0;
1044 for (token = key->payload.data; token; token = token->next) {
1045 toksize = 4; /* sec index */
1046
1047 switch (token->security_index) {
1048 case RXRPC_SECURITY_RXKAD:
1049 toksize += 8 * 4; /* viceid, kvno, key*2, begin,
1050 * end, primary, tktlen */
1051 toksize += RND(token->kad->ticket_len);
1052 break;
1053
1054 case RXRPC_SECURITY_RXK5:
1055 princ = &token->k5->client;
1056 toksize += 4 + princ->n_name_parts * 4;
1057 for (loop = 0; loop < princ->n_name_parts; loop++)
1058 toksize += RND(strlen(princ->name_parts[loop]));
1059 toksize += 4 + RND(strlen(princ->realm));
1060
1061 princ = &token->k5->server;
1062 toksize += 4 + princ->n_name_parts * 4;
1063 for (loop = 0; loop < princ->n_name_parts; loop++)
1064 toksize += RND(strlen(princ->name_parts[loop]));
1065 toksize += 4 + RND(strlen(princ->realm));
1066
1067 toksize += 8 + RND(token->k5->session.data_len);
1068
1069 toksize += 4 * 8 + 2 * 4;
1070
1071 toksize += 4 + token->k5->n_addresses * 8;
1072 for (loop = 0; loop < token->k5->n_addresses; loop++)
1073 toksize += RND(token->k5->addresses[loop].data_len);
1074
1075 toksize += 4 + RND(token->k5->ticket_len);
1076 toksize += 4 + RND(token->k5->ticket2_len);
1077
1078 toksize += 4 + token->k5->n_authdata * 8;
1079 for (loop = 0; loop < token->k5->n_authdata; loop++)
1080 toksize += RND(token->k5->authdata[loop].data_len);
1081 break;
1082
1083 default: /* we have a ticket we can't encode */
1084 BUG();
1085 continue;
1086 }
1087
1088 _debug("token[%u]: toksize=%u", ntoks, toksize);
1089 ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
1090
1091 toksizes[ntoks++] = toksize;
1092 size += toksize + 4; /* each token has a length word */
1093 }
1094
1095 #undef RND
1096
1097 if (!buffer || buflen < size)
1098 return size;
1099
1100 xdr = (__be32 __user *) buffer;
1101 zero = 0;
1102 #define ENCODE(x) \
1103 do { \
1104 __be32 y = htonl(x); \
1105 if (put_user(y, xdr++) < 0) \
1106 goto fault; \
1107 } while(0)
1108 #define ENCODE_DATA(l, s) \
1109 do { \
1110 u32 _l = (l); \
1111 ENCODE(l); \
1112 if (copy_to_user(xdr, (s), _l) != 0) \
1113 goto fault; \
1114 if (_l & 3 && \
1115 copy_to_user((u8 *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
1116 goto fault; \
1117 xdr += (_l + 3) >> 2; \
1118 } while(0)
1119 #define ENCODE64(x) \
1120 do { \
1121 __be64 y = cpu_to_be64(x); \
1122 if (copy_to_user(xdr, &y, 8) != 0) \
1123 goto fault; \
1124 xdr += 8 >> 2; \
1125 } while(0)
1126 #define ENCODE_STR(s) \
1127 do { \
1128 const char *_s = (s); \
1129 ENCODE_DATA(strlen(_s), _s); \
1130 } while(0)
1131
1132 ENCODE(0); /* flags */
1133 ENCODE_DATA(cnlen, key->description + 4); /* cellname */
1134 ENCODE(ntoks);
1135
1136 tok = 0;
1137 for (token = key->payload.data; token; token = token->next) {
1138 toksize = toksizes[tok++];
1139 ENCODE(toksize);
1140 oldxdr = xdr;
1141 ENCODE(token->security_index);
1142
1143 switch (token->security_index) {
1144 case RXRPC_SECURITY_RXKAD:
1145 ENCODE(token->kad->vice_id);
1146 ENCODE(token->kad->kvno);
1147 ENCODE_DATA(8, token->kad->session_key);
1148 ENCODE(token->kad->start);
1149 ENCODE(token->kad->expiry);
1150 ENCODE(token->kad->primary_flag);
1151 ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
1152 break;
1153
1154 case RXRPC_SECURITY_RXK5:
1155 princ = &token->k5->client;
1156 ENCODE(princ->n_name_parts);
1157 for (loop = 0; loop < princ->n_name_parts; loop++)
1158 ENCODE_STR(princ->name_parts[loop]);
1159 ENCODE_STR(princ->realm);
1160
1161 princ = &token->k5->server;
1162 ENCODE(princ->n_name_parts);
1163 for (loop = 0; loop < princ->n_name_parts; loop++)
1164 ENCODE_STR(princ->name_parts[loop]);
1165 ENCODE_STR(princ->realm);
1166
1167 ENCODE(token->k5->session.tag);
1168 ENCODE_DATA(token->k5->session.data_len,
1169 token->k5->session.data);
1170
1171 ENCODE64(token->k5->authtime);
1172 ENCODE64(token->k5->starttime);
1173 ENCODE64(token->k5->endtime);
1174 ENCODE64(token->k5->renew_till);
1175 ENCODE(token->k5->is_skey);
1176 ENCODE(token->k5->flags);
1177
1178 ENCODE(token->k5->n_addresses);
1179 for (loop = 0; loop < token->k5->n_addresses; loop++) {
1180 ENCODE(token->k5->addresses[loop].tag);
1181 ENCODE_DATA(token->k5->addresses[loop].data_len,
1182 token->k5->addresses[loop].data);
1183 }
1184
1185 ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
1186 ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
1187
1188 ENCODE(token->k5->n_authdata);
1189 for (loop = 0; loop < token->k5->n_authdata; loop++) {
1190 ENCODE(token->k5->authdata[loop].tag);
1191 ENCODE_DATA(token->k5->authdata[loop].data_len,
1192 token->k5->authdata[loop].data);
1193 }
1194 break;
1195
1196 default:
1197 BUG();
1198 break;
1199 }
1200
1201 ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
1202 toksize);
1203 }
1204
1205 #undef ENCODE_STR
1206 #undef ENCODE_DATA
1207 #undef ENCODE64
1208 #undef ENCODE
1209
1210 ASSERTCMP(tok, ==, ntoks);
1211 ASSERTCMP((char __user *) xdr - buffer, ==, size);
1212 _leave(" = %zu", size);
1213 return size;
1214
1215 fault:
1216 _leave(" = -EFAULT");
1217 return -EFAULT;
1218 }
1219