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(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 */
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 = 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 */
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)329 static 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 */
rxrpc_krb5_decode_ticket(u8 ** _ticket,u16 * _tktlen,const __be32 ** _xdr,unsigned * _toklen)383 static 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 */
rxrpc_instantiate_xdr_rxk5(struct key * key,const __be32 * xdr,unsigned toklen)423 static 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
537 inval:
538 ret = -EINVAL;
539 error:
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 */
rxrpc_instantiate_xdr(struct key * key,const void * data,size_t datalen)550 static 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
661 not_xdr:
662 _leave(" = -EPROTO");
663 return -EPROTO;
664 error:
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 */
rxrpc_instantiate(struct key * key,const void * data,size_t datalen)683 static 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
779 error_free:
780 kfree(token);
781 error:
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 */
rxrpc_instantiate_s(struct key * key,const void * data,size_t datalen)789 static 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 */
rxrpc_destroy(struct key * key)818 static 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 */
rxrpc_destroy_s(struct key * key)845 static 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 */
rxrpc_describe(const struct key * key,struct seq_file * m)856 static 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 */
rxrpc_request_key(struct rxrpc_sock * rx,char __user * optval,int optlen)864 int 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 */
rxrpc_server_keyring(struct rxrpc_sock * rx,char __user * optval,int optlen)900 int 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 */
rxrpc_get_server_data_key(struct rxrpc_connection * conn,const void * session_key,time_t expiry,u32 kvno)937 int 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
978 error:
979 key_revoke(key);
980 key_put(key);
981 _leave(" = -ENOMEM [ins %d]", ret);
982 return -ENOMEM;
983 }
984 EXPORT_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 */
rxrpc_get_null_key(const char * keyname)993 struct 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 }
1013 EXPORT_SYMBOL(rxrpc_get_null_key);
1014
1015 /*
1016 * read the contents of an rxrpc key
1017 * - this returns the result in XDR form
1018 */
rxrpc_read(const struct key * key,char __user * buffer,size_t buflen)1019 static 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
1217 fault:
1218 _leave(" = -EFAULT");
1219 return -EFAULT;
1220 }
1221