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_preparse(struct key_preparsed_payload *);
30 static int rxrpc_preparse_s(struct key_preparsed_payload *);
31 static void rxrpc_free_preparse(struct key_preparsed_payload *);
32 static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
33 static void rxrpc_destroy(struct key *);
34 static void rxrpc_destroy_s(struct key *);
35 static void rxrpc_describe(const struct key *, struct seq_file *);
36 static long rxrpc_read(const struct key *, char __user *, size_t);
37
38 /*
39 * rxrpc defined keys take an arbitrary string as the description and an
40 * arbitrary blob of data as the payload
41 */
42 struct key_type key_type_rxrpc = {
43 .name = "rxrpc",
44 .preparse = rxrpc_preparse,
45 .free_preparse = rxrpc_free_preparse,
46 .instantiate = generic_key_instantiate,
47 .destroy = rxrpc_destroy,
48 .describe = rxrpc_describe,
49 .read = rxrpc_read,
50 };
51 EXPORT_SYMBOL(key_type_rxrpc);
52
53 /*
54 * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
55 * description and an 8-byte decryption key as the payload
56 */
57 struct key_type key_type_rxrpc_s = {
58 .name = "rxrpc_s",
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 size_t plen;
94 u32 tktlen;
95
96 _enter(",{%x,%x,%x,%x},%u",
97 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
98 toklen);
99
100 if (toklen <= 8 * 4)
101 return -EKEYREJECTED;
102 tktlen = ntohl(xdr[7]);
103 _debug("tktlen: %x", tktlen);
104 if (tktlen > AFSTOKEN_RK_TIX_MAX)
105 return -EKEYREJECTED;
106 if (toklen < 8 * 4 + tktlen)
107 return -EKEYREJECTED;
108
109 plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
110 prep->quotalen = datalen + plen;
111
112 plen -= sizeof(*token);
113 token = kzalloc(sizeof(*token), GFP_KERNEL);
114 if (!token)
115 return -ENOMEM;
116
117 token->kad = kzalloc(plen, GFP_KERNEL);
118 if (!token->kad) {
119 kfree(token);
120 return -ENOMEM;
121 }
122
123 token->security_index = RXRPC_SECURITY_RXKAD;
124 token->kad->ticket_len = tktlen;
125 token->kad->vice_id = ntohl(xdr[0]);
126 token->kad->kvno = ntohl(xdr[1]);
127 token->kad->start = ntohl(xdr[4]);
128 token->kad->expiry = ntohl(xdr[5]);
129 token->kad->primary_flag = ntohl(xdr[6]);
130 memcpy(&token->kad->session_key, &xdr[2], 8);
131 memcpy(&token->kad->ticket, &xdr[8], tktlen);
132
133 _debug("SCIX: %u", token->security_index);
134 _debug("TLEN: %u", token->kad->ticket_len);
135 _debug("EXPY: %x", token->kad->expiry);
136 _debug("KVNO: %u", token->kad->kvno);
137 _debug("PRIM: %u", token->kad->primary_flag);
138 _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
139 token->kad->session_key[0], token->kad->session_key[1],
140 token->kad->session_key[2], token->kad->session_key[3],
141 token->kad->session_key[4], token->kad->session_key[5],
142 token->kad->session_key[6], token->kad->session_key[7]);
143 if (token->kad->ticket_len >= 8)
144 _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
145 token->kad->ticket[0], token->kad->ticket[1],
146 token->kad->ticket[2], token->kad->ticket[3],
147 token->kad->ticket[4], token->kad->ticket[5],
148 token->kad->ticket[6], token->kad->ticket[7]);
149
150 /* count the number of tokens attached */
151 prep->type_data[0] = (void *)((unsigned long)prep->type_data[0] + 1);
152
153 /* attach the data */
154 for (pptoken = (struct rxrpc_key_token **)&prep->payload[0];
155 *pptoken;
156 pptoken = &(*pptoken)->next)
157 continue;
158 *pptoken = token;
159 if (token->kad->expiry < prep->expiry)
160 prep->expiry = token->kad->expiry;
161
162 _leave(" = 0");
163 return 0;
164 }
165
rxrpc_free_krb5_principal(struct krb5_principal * princ)166 static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
167 {
168 int loop;
169
170 if (princ->name_parts) {
171 for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
172 kfree(princ->name_parts[loop]);
173 kfree(princ->name_parts);
174 }
175 kfree(princ->realm);
176 }
177
rxrpc_free_krb5_tagged(struct krb5_tagged_data * td)178 static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
179 {
180 kfree(td->data);
181 }
182
183 /*
184 * free up an RxK5 token
185 */
rxrpc_rxk5_free(struct rxk5_key * rxk5)186 static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
187 {
188 int loop;
189
190 rxrpc_free_krb5_principal(&rxk5->client);
191 rxrpc_free_krb5_principal(&rxk5->server);
192 rxrpc_free_krb5_tagged(&rxk5->session);
193
194 if (rxk5->addresses) {
195 for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
196 rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
197 kfree(rxk5->addresses);
198 }
199 if (rxk5->authdata) {
200 for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
201 rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
202 kfree(rxk5->authdata);
203 }
204
205 kfree(rxk5->ticket);
206 kfree(rxk5->ticket2);
207 kfree(rxk5);
208 }
209
210 /*
211 * extract a krb5 principal
212 */
rxrpc_krb5_decode_principal(struct krb5_principal * princ,const __be32 ** _xdr,unsigned int * _toklen)213 static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
214 const __be32 **_xdr,
215 unsigned int *_toklen)
216 {
217 const __be32 *xdr = *_xdr;
218 unsigned int toklen = *_toklen, n_parts, loop, tmp;
219
220 /* there must be at least one name, and at least #names+1 length
221 * words */
222 if (toklen <= 12)
223 return -EINVAL;
224
225 _enter(",{%x,%x,%x},%u",
226 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
227
228 n_parts = ntohl(*xdr++);
229 toklen -= 4;
230 if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
231 return -EINVAL;
232 princ->n_name_parts = n_parts;
233
234 if (toklen <= (n_parts + 1) * 4)
235 return -EINVAL;
236
237 princ->name_parts = kcalloc(n_parts, sizeof(char *), GFP_KERNEL);
238 if (!princ->name_parts)
239 return -ENOMEM;
240
241 for (loop = 0; loop < n_parts; loop++) {
242 if (toklen < 4)
243 return -EINVAL;
244 tmp = ntohl(*xdr++);
245 toklen -= 4;
246 if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
247 return -EINVAL;
248 if (tmp > toklen)
249 return -EINVAL;
250 princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
251 if (!princ->name_parts[loop])
252 return -ENOMEM;
253 memcpy(princ->name_parts[loop], xdr, tmp);
254 princ->name_parts[loop][tmp] = 0;
255 tmp = (tmp + 3) & ~3;
256 toklen -= tmp;
257 xdr += tmp >> 2;
258 }
259
260 if (toklen < 4)
261 return -EINVAL;
262 tmp = ntohl(*xdr++);
263 toklen -= 4;
264 if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
265 return -EINVAL;
266 if (tmp > toklen)
267 return -EINVAL;
268 princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
269 if (!princ->realm)
270 return -ENOMEM;
271 memcpy(princ->realm, xdr, tmp);
272 princ->realm[tmp] = 0;
273 tmp = (tmp + 3) & ~3;
274 toklen -= tmp;
275 xdr += tmp >> 2;
276
277 _debug("%s/...@%s", princ->name_parts[0], princ->realm);
278
279 *_xdr = xdr;
280 *_toklen = toklen;
281 _leave(" = 0 [toklen=%u]", toklen);
282 return 0;
283 }
284
285 /*
286 * extract a piece of krb5 tagged data
287 */
rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data * td,size_t max_data_size,const __be32 ** _xdr,unsigned int * _toklen)288 static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
289 size_t max_data_size,
290 const __be32 **_xdr,
291 unsigned int *_toklen)
292 {
293 const __be32 *xdr = *_xdr;
294 unsigned int toklen = *_toklen, len;
295
296 /* there must be at least one tag and one length word */
297 if (toklen <= 8)
298 return -EINVAL;
299
300 _enter(",%zu,{%x,%x},%u",
301 max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
302
303 td->tag = ntohl(*xdr++);
304 len = ntohl(*xdr++);
305 toklen -= 8;
306 if (len > max_data_size)
307 return -EINVAL;
308 td->data_len = len;
309
310 if (len > 0) {
311 td->data = kmemdup(xdr, len, GFP_KERNEL);
312 if (!td->data)
313 return -ENOMEM;
314 len = (len + 3) & ~3;
315 toklen -= len;
316 xdr += len >> 2;
317 }
318
319 _debug("tag %x len %x", td->tag, td->data_len);
320
321 *_xdr = xdr;
322 *_toklen = toklen;
323 _leave(" = 0 [toklen=%u]", toklen);
324 return 0;
325 }
326
327 /*
328 * extract an array of tagged data
329 */
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)330 static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
331 u8 *_n_elem,
332 u8 max_n_elem,
333 size_t max_elem_size,
334 const __be32 **_xdr,
335 unsigned int *_toklen)
336 {
337 struct krb5_tagged_data *td;
338 const __be32 *xdr = *_xdr;
339 unsigned int toklen = *_toklen, n_elem, loop;
340 int ret;
341
342 /* there must be at least one count */
343 if (toklen < 4)
344 return -EINVAL;
345
346 _enter(",,%u,%zu,{%x},%u",
347 max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
348
349 n_elem = ntohl(*xdr++);
350 toklen -= 4;
351 if (n_elem > max_n_elem)
352 return -EINVAL;
353 *_n_elem = n_elem;
354 if (n_elem > 0) {
355 if (toklen <= (n_elem + 1) * 4)
356 return -EINVAL;
357
358 _debug("n_elem %d", n_elem);
359
360 td = kcalloc(n_elem, sizeof(struct krb5_tagged_data),
361 GFP_KERNEL);
362 if (!td)
363 return -ENOMEM;
364 *_td = td;
365
366 for (loop = 0; loop < n_elem; loop++) {
367 ret = rxrpc_krb5_decode_tagged_data(&td[loop],
368 max_elem_size,
369 &xdr, &toklen);
370 if (ret < 0)
371 return ret;
372 }
373 }
374
375 *_xdr = xdr;
376 *_toklen = toklen;
377 _leave(" = 0 [toklen=%u]", toklen);
378 return 0;
379 }
380
381 /*
382 * extract a krb5 ticket
383 */
rxrpc_krb5_decode_ticket(u8 ** _ticket,u16 * _tktlen,const __be32 ** _xdr,unsigned int * _toklen)384 static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
385 const __be32 **_xdr, unsigned int *_toklen)
386 {
387 const __be32 *xdr = *_xdr;
388 unsigned int toklen = *_toklen, len;
389
390 /* there must be at least one length word */
391 if (toklen <= 4)
392 return -EINVAL;
393
394 _enter(",{%x},%u", ntohl(xdr[0]), toklen);
395
396 len = ntohl(*xdr++);
397 toklen -= 4;
398 if (len > AFSTOKEN_K5_TIX_MAX)
399 return -EINVAL;
400 *_tktlen = len;
401
402 _debug("ticket len %u", len);
403
404 if (len > 0) {
405 *_ticket = kmemdup(xdr, len, GFP_KERNEL);
406 if (!*_ticket)
407 return -ENOMEM;
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_preparse_xdr_rxk5(struct key_preparsed_payload * prep,size_t datalen,const __be32 * xdr,unsigned int toklen)423 static int rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
424 size_t datalen,
425 const __be32 *xdr, unsigned int toklen)
426 {
427 struct rxrpc_key_token *token, **pptoken;
428 struct rxk5_key *rxk5;
429 const __be32 *end_xdr = xdr + (toklen >> 2);
430 int ret;
431
432 _enter(",{%x,%x,%x,%x},%u",
433 ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
434 toklen);
435
436 /* reserve some payload space for this subkey - the length of the token
437 * is a reasonable approximation */
438 prep->quotalen = datalen + toklen;
439
440 token = kzalloc(sizeof(*token), GFP_KERNEL);
441 if (!token)
442 return -ENOMEM;
443
444 rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
445 if (!rxk5) {
446 kfree(token);
447 return -ENOMEM;
448 }
449
450 token->security_index = RXRPC_SECURITY_RXK5;
451 token->k5 = rxk5;
452
453 /* extract the principals */
454 ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
455 if (ret < 0)
456 goto error;
457 ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
458 if (ret < 0)
459 goto error;
460
461 /* extract the session key and the encoding type (the tag field ->
462 * ENCTYPE_xxx) */
463 ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
464 &xdr, &toklen);
465 if (ret < 0)
466 goto error;
467
468 if (toklen < 4 * 8 + 2 * 4)
469 goto inval;
470 rxk5->authtime = be64_to_cpup((const __be64 *) xdr);
471 xdr += 2;
472 rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
473 xdr += 2;
474 rxk5->endtime = be64_to_cpup((const __be64 *) xdr);
475 xdr += 2;
476 rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
477 xdr += 2;
478 rxk5->is_skey = ntohl(*xdr++);
479 rxk5->flags = ntohl(*xdr++);
480 toklen -= 4 * 8 + 2 * 4;
481
482 _debug("times: a=%llx s=%llx e=%llx rt=%llx",
483 rxk5->authtime, rxk5->starttime, rxk5->endtime,
484 rxk5->renew_till);
485 _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
486
487 /* extract the permitted client addresses */
488 ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
489 &rxk5->n_addresses,
490 AFSTOKEN_K5_ADDRESSES_MAX,
491 AFSTOKEN_DATA_MAX,
492 &xdr, &toklen);
493 if (ret < 0)
494 goto error;
495
496 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
497
498 /* extract the tickets */
499 ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
500 &xdr, &toklen);
501 if (ret < 0)
502 goto error;
503 ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
504 &xdr, &toklen);
505 if (ret < 0)
506 goto error;
507
508 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
509
510 /* extract the typed auth data */
511 ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
512 &rxk5->n_authdata,
513 AFSTOKEN_K5_AUTHDATA_MAX,
514 AFSTOKEN_BDATALN_MAX,
515 &xdr, &toklen);
516 if (ret < 0)
517 goto error;
518
519 ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
520
521 if (toklen != 0)
522 goto inval;
523
524 /* attach the payload */
525 for (pptoken = (struct rxrpc_key_token **)&prep->payload[0];
526 *pptoken;
527 pptoken = &(*pptoken)->next)
528 continue;
529 *pptoken = token;
530 if (token->kad->expiry < prep->expiry)
531 prep->expiry = token->kad->expiry;
532
533 _leave(" = 0");
534 return 0;
535
536 inval:
537 ret = -EINVAL;
538 error:
539 rxrpc_rxk5_free(rxk5);
540 kfree(token);
541 _leave(" = %d", ret);
542 return ret;
543 }
544
545 /*
546 * attempt to parse the data as the XDR format
547 * - the caller guarantees we have more than 7 words
548 */
rxrpc_preparse_xdr(struct key_preparsed_payload * prep)549 static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
550 {
551 const __be32 *xdr = prep->data, *token;
552 const char *cp;
553 unsigned int len, tmp, loop, ntoken, toklen, sec_ix;
554 size_t datalen = prep->datalen;
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 prep->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_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
641 if (ret != 0)
642 goto error;
643 break;
644
645 case RXRPC_SECURITY_RXK5:
646 ret = rxrpc_preparse_xdr_rxk5(prep, datalen, 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 * Preparse an rxrpc defined key.
671 *
672 * Data should be of the form:
673 * OFFSET LEN CONTENT
674 * 0 4 key interface version number
675 * 4 2 security index (type)
676 * 6 2 ticket length
677 * 8 4 key expiry time (time_t)
678 * 12 4 kvno
679 * 16 8 session key
680 * 24 [len] ticket
681 *
682 * if no data is provided, then a no-security key is made
683 */
rxrpc_preparse(struct key_preparsed_payload * prep)684 static int rxrpc_preparse(struct key_preparsed_payload *prep)
685 {
686 const struct rxrpc_key_data_v1 *v1;
687 struct rxrpc_key_token *token, **pp;
688 size_t plen;
689 u32 kver;
690 int ret;
691
692 _enter("%zu", prep->datalen);
693
694 /* handle a no-security key */
695 if (!prep->data && prep->datalen == 0)
696 return 0;
697
698 /* determine if the XDR payload format is being used */
699 if (prep->datalen > 7 * 4) {
700 ret = rxrpc_preparse_xdr(prep);
701 if (ret != -EPROTO)
702 return ret;
703 }
704
705 /* get the key interface version number */
706 ret = -EINVAL;
707 if (prep->datalen <= 4 || !prep->data)
708 goto error;
709 memcpy(&kver, prep->data, sizeof(kver));
710 prep->data += sizeof(kver);
711 prep->datalen -= sizeof(kver);
712
713 _debug("KEY I/F VERSION: %u", kver);
714
715 ret = -EKEYREJECTED;
716 if (kver != 1)
717 goto error;
718
719 /* deal with a version 1 key */
720 ret = -EINVAL;
721 if (prep->datalen < sizeof(*v1))
722 goto error;
723
724 v1 = prep->data;
725 if (prep->datalen != sizeof(*v1) + v1->ticket_length)
726 goto error;
727
728 _debug("SCIX: %u", v1->security_index);
729 _debug("TLEN: %u", v1->ticket_length);
730 _debug("EXPY: %x", v1->expiry);
731 _debug("KVNO: %u", v1->kvno);
732 _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
733 v1->session_key[0], v1->session_key[1],
734 v1->session_key[2], v1->session_key[3],
735 v1->session_key[4], v1->session_key[5],
736 v1->session_key[6], v1->session_key[7]);
737 if (v1->ticket_length >= 8)
738 _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
739 v1->ticket[0], v1->ticket[1],
740 v1->ticket[2], v1->ticket[3],
741 v1->ticket[4], v1->ticket[5],
742 v1->ticket[6], v1->ticket[7]);
743
744 ret = -EPROTONOSUPPORT;
745 if (v1->security_index != RXRPC_SECURITY_RXKAD)
746 goto error;
747
748 plen = sizeof(*token->kad) + v1->ticket_length;
749 prep->quotalen = plen + sizeof(*token);
750
751 ret = -ENOMEM;
752 token = kzalloc(sizeof(*token), GFP_KERNEL);
753 if (!token)
754 goto error;
755 token->kad = kzalloc(plen, GFP_KERNEL);
756 if (!token->kad)
757 goto error_free;
758
759 token->security_index = RXRPC_SECURITY_RXKAD;
760 token->kad->ticket_len = v1->ticket_length;
761 token->kad->expiry = v1->expiry;
762 token->kad->kvno = v1->kvno;
763 memcpy(&token->kad->session_key, &v1->session_key, 8);
764 memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
765
766 /* count the number of tokens attached */
767 prep->type_data[0] = (void *)((unsigned long)prep->type_data[0] + 1);
768
769 /* attach the data */
770 pp = (struct rxrpc_key_token **)&prep->payload[0];
771 while (*pp)
772 pp = &(*pp)->next;
773 *pp = token;
774 if (token->kad->expiry < prep->expiry)
775 prep->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 * Free token list.
787 */
rxrpc_free_token_list(struct rxrpc_key_token * token)788 static void rxrpc_free_token_list(struct rxrpc_key_token *token)
789 {
790 struct rxrpc_key_token *next;
791
792 for (; token; token = next) {
793 next = token->next;
794 switch (token->security_index) {
795 case RXRPC_SECURITY_RXKAD:
796 kfree(token->kad);
797 break;
798 case RXRPC_SECURITY_RXK5:
799 if (token->k5)
800 rxrpc_rxk5_free(token->k5);
801 break;
802 default:
803 printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
804 token->security_index);
805 BUG();
806 }
807
808 kfree(token);
809 }
810 }
811
812 /*
813 * Clean up preparse data.
814 */
rxrpc_free_preparse(struct key_preparsed_payload * prep)815 static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
816 {
817 rxrpc_free_token_list(prep->payload[0]);
818 }
819
820 /*
821 * Preparse a server secret key.
822 *
823 * The data should be the 8-byte secret key.
824 */
rxrpc_preparse_s(struct key_preparsed_payload * prep)825 static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
826 {
827 struct crypto_blkcipher *ci;
828
829 _enter("%zu", prep->datalen);
830
831 if (prep->datalen != 8)
832 return -EINVAL;
833
834 memcpy(&prep->type_data, prep->data, 8);
835
836 ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
837 if (IS_ERR(ci)) {
838 _leave(" = %ld", PTR_ERR(ci));
839 return PTR_ERR(ci);
840 }
841
842 if (crypto_blkcipher_setkey(ci, prep->data, 8) < 0)
843 BUG();
844
845 prep->payload[0] = ci;
846 _leave(" = 0");
847 return 0;
848 }
849
850 /*
851 * Clean up preparse data.
852 */
rxrpc_free_preparse_s(struct key_preparsed_payload * prep)853 static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
854 {
855 if (prep->payload[0])
856 crypto_free_blkcipher(prep->payload[0]);
857 }
858
859 /*
860 * dispose of the data dangling from the corpse of a rxrpc key
861 */
rxrpc_destroy(struct key * key)862 static void rxrpc_destroy(struct key *key)
863 {
864 rxrpc_free_token_list(key->payload.data);
865 }
866
867 /*
868 * dispose of the data dangling from the corpse of a rxrpc key
869 */
rxrpc_destroy_s(struct key * key)870 static void rxrpc_destroy_s(struct key *key)
871 {
872 if (key->payload.data) {
873 crypto_free_blkcipher(key->payload.data);
874 key->payload.data = NULL;
875 }
876 }
877
878 /*
879 * describe the rxrpc key
880 */
rxrpc_describe(const struct key * key,struct seq_file * m)881 static void rxrpc_describe(const struct key *key, struct seq_file *m)
882 {
883 seq_puts(m, key->description);
884 }
885
886 /*
887 * grab the security key for a socket
888 */
rxrpc_request_key(struct rxrpc_sock * rx,char __user * optval,int optlen)889 int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
890 {
891 struct key *key;
892 char *description;
893
894 _enter("");
895
896 if (optlen <= 0 || optlen > PAGE_SIZE - 1)
897 return -EINVAL;
898
899 description = kmalloc(optlen + 1, GFP_KERNEL);
900 if (!description)
901 return -ENOMEM;
902
903 if (copy_from_user(description, optval, optlen)) {
904 kfree(description);
905 return -EFAULT;
906 }
907 description[optlen] = 0;
908
909 key = request_key(&key_type_rxrpc, description, NULL);
910 if (IS_ERR(key)) {
911 kfree(description);
912 _leave(" = %ld", PTR_ERR(key));
913 return PTR_ERR(key);
914 }
915
916 rx->key = key;
917 kfree(description);
918 _leave(" = 0 [key %x]", key->serial);
919 return 0;
920 }
921
922 /*
923 * grab the security keyring for a server socket
924 */
rxrpc_server_keyring(struct rxrpc_sock * rx,char __user * optval,int optlen)925 int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
926 int optlen)
927 {
928 struct key *key;
929 char *description;
930
931 _enter("");
932
933 if (optlen <= 0 || optlen > PAGE_SIZE - 1)
934 return -EINVAL;
935
936 description = kmalloc(optlen + 1, GFP_KERNEL);
937 if (!description)
938 return -ENOMEM;
939
940 if (copy_from_user(description, optval, optlen)) {
941 kfree(description);
942 return -EFAULT;
943 }
944 description[optlen] = 0;
945
946 key = request_key(&key_type_keyring, description, NULL);
947 if (IS_ERR(key)) {
948 kfree(description);
949 _leave(" = %ld", PTR_ERR(key));
950 return PTR_ERR(key);
951 }
952
953 rx->securities = key;
954 kfree(description);
955 _leave(" = 0 [key %x]", key->serial);
956 return 0;
957 }
958
959 /*
960 * generate a server data key
961 */
rxrpc_get_server_data_key(struct rxrpc_connection * conn,const void * session_key,time_t expiry,u32 kvno)962 int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
963 const void *session_key,
964 time_t expiry,
965 u32 kvno)
966 {
967 const struct cred *cred = current_cred();
968 struct key *key;
969 int ret;
970
971 struct {
972 u32 kver;
973 struct rxrpc_key_data_v1 v1;
974 } data;
975
976 _enter("");
977
978 key = key_alloc(&key_type_rxrpc, "x",
979 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
980 KEY_ALLOC_NOT_IN_QUOTA);
981 if (IS_ERR(key)) {
982 _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
983 return -ENOMEM;
984 }
985
986 _debug("key %d", key_serial(key));
987
988 data.kver = 1;
989 data.v1.security_index = RXRPC_SECURITY_RXKAD;
990 data.v1.ticket_length = 0;
991 data.v1.expiry = expiry;
992 data.v1.kvno = 0;
993
994 memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
995
996 ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
997 if (ret < 0)
998 goto error;
999
1000 conn->key = key;
1001 _leave(" = 0 [%d]", key_serial(key));
1002 return 0;
1003
1004 error:
1005 key_revoke(key);
1006 key_put(key);
1007 _leave(" = -ENOMEM [ins %d]", ret);
1008 return -ENOMEM;
1009 }
1010 EXPORT_SYMBOL(rxrpc_get_server_data_key);
1011
1012 /**
1013 * rxrpc_get_null_key - Generate a null RxRPC key
1014 * @keyname: The name to give the key.
1015 *
1016 * Generate a null RxRPC key that can be used to indicate anonymous security is
1017 * required for a particular domain.
1018 */
rxrpc_get_null_key(const char * keyname)1019 struct key *rxrpc_get_null_key(const char *keyname)
1020 {
1021 const struct cred *cred = current_cred();
1022 struct key *key;
1023 int ret;
1024
1025 key = key_alloc(&key_type_rxrpc, keyname,
1026 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
1027 KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
1028 if (IS_ERR(key))
1029 return key;
1030
1031 ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
1032 if (ret < 0) {
1033 key_revoke(key);
1034 key_put(key);
1035 return ERR_PTR(ret);
1036 }
1037
1038 return key;
1039 }
1040 EXPORT_SYMBOL(rxrpc_get_null_key);
1041
1042 /*
1043 * read the contents of an rxrpc key
1044 * - this returns the result in XDR form
1045 */
rxrpc_read(const struct key * key,char __user * buffer,size_t buflen)1046 static long rxrpc_read(const struct key *key,
1047 char __user *buffer, size_t buflen)
1048 {
1049 const struct rxrpc_key_token *token;
1050 const struct krb5_principal *princ;
1051 size_t size;
1052 __be32 __user *xdr, *oldxdr;
1053 u32 cnlen, toksize, ntoks, tok, zero;
1054 u16 toksizes[AFSTOKEN_MAX];
1055 int loop;
1056
1057 _enter("");
1058
1059 /* we don't know what form we should return non-AFS keys in */
1060 if (memcmp(key->description, "afs@", 4) != 0)
1061 return -EOPNOTSUPP;
1062 cnlen = strlen(key->description + 4);
1063
1064 #define RND(X) (((X) + 3) & ~3)
1065
1066 /* AFS keys we return in XDR form, so we need to work out the size of
1067 * the XDR */
1068 size = 2 * 4; /* flags, cellname len */
1069 size += RND(cnlen); /* cellname */
1070 size += 1 * 4; /* token count */
1071
1072 ntoks = 0;
1073 for (token = key->payload.data; token; token = token->next) {
1074 toksize = 4; /* sec index */
1075
1076 switch (token->security_index) {
1077 case RXRPC_SECURITY_RXKAD:
1078 toksize += 8 * 4; /* viceid, kvno, key*2, begin,
1079 * end, primary, tktlen */
1080 toksize += RND(token->kad->ticket_len);
1081 break;
1082
1083 case RXRPC_SECURITY_RXK5:
1084 princ = &token->k5->client;
1085 toksize += 4 + princ->n_name_parts * 4;
1086 for (loop = 0; loop < princ->n_name_parts; loop++)
1087 toksize += RND(strlen(princ->name_parts[loop]));
1088 toksize += 4 + RND(strlen(princ->realm));
1089
1090 princ = &token->k5->server;
1091 toksize += 4 + princ->n_name_parts * 4;
1092 for (loop = 0; loop < princ->n_name_parts; loop++)
1093 toksize += RND(strlen(princ->name_parts[loop]));
1094 toksize += 4 + RND(strlen(princ->realm));
1095
1096 toksize += 8 + RND(token->k5->session.data_len);
1097
1098 toksize += 4 * 8 + 2 * 4;
1099
1100 toksize += 4 + token->k5->n_addresses * 8;
1101 for (loop = 0; loop < token->k5->n_addresses; loop++)
1102 toksize += RND(token->k5->addresses[loop].data_len);
1103
1104 toksize += 4 + RND(token->k5->ticket_len);
1105 toksize += 4 + RND(token->k5->ticket2_len);
1106
1107 toksize += 4 + token->k5->n_authdata * 8;
1108 for (loop = 0; loop < token->k5->n_authdata; loop++)
1109 toksize += RND(token->k5->authdata[loop].data_len);
1110 break;
1111
1112 default: /* we have a ticket we can't encode */
1113 BUG();
1114 continue;
1115 }
1116
1117 _debug("token[%u]: toksize=%u", ntoks, toksize);
1118 ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
1119
1120 toksizes[ntoks++] = toksize;
1121 size += toksize + 4; /* each token has a length word */
1122 }
1123
1124 #undef RND
1125
1126 if (!buffer || buflen < size)
1127 return size;
1128
1129 xdr = (__be32 __user *) buffer;
1130 zero = 0;
1131 #define ENCODE(x) \
1132 do { \
1133 __be32 y = htonl(x); \
1134 if (put_user(y, xdr++) < 0) \
1135 goto fault; \
1136 } while(0)
1137 #define ENCODE_DATA(l, s) \
1138 do { \
1139 u32 _l = (l); \
1140 ENCODE(l); \
1141 if (copy_to_user(xdr, (s), _l) != 0) \
1142 goto fault; \
1143 if (_l & 3 && \
1144 copy_to_user((u8 __user *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
1145 goto fault; \
1146 xdr += (_l + 3) >> 2; \
1147 } while(0)
1148 #define ENCODE64(x) \
1149 do { \
1150 __be64 y = cpu_to_be64(x); \
1151 if (copy_to_user(xdr, &y, 8) != 0) \
1152 goto fault; \
1153 xdr += 8 >> 2; \
1154 } while(0)
1155 #define ENCODE_STR(s) \
1156 do { \
1157 const char *_s = (s); \
1158 ENCODE_DATA(strlen(_s), _s); \
1159 } while(0)
1160
1161 ENCODE(0); /* flags */
1162 ENCODE_DATA(cnlen, key->description + 4); /* cellname */
1163 ENCODE(ntoks);
1164
1165 tok = 0;
1166 for (token = key->payload.data; token; token = token->next) {
1167 toksize = toksizes[tok++];
1168 ENCODE(toksize);
1169 oldxdr = xdr;
1170 ENCODE(token->security_index);
1171
1172 switch (token->security_index) {
1173 case RXRPC_SECURITY_RXKAD:
1174 ENCODE(token->kad->vice_id);
1175 ENCODE(token->kad->kvno);
1176 ENCODE_DATA(8, token->kad->session_key);
1177 ENCODE(token->kad->start);
1178 ENCODE(token->kad->expiry);
1179 ENCODE(token->kad->primary_flag);
1180 ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
1181 break;
1182
1183 case RXRPC_SECURITY_RXK5:
1184 princ = &token->k5->client;
1185 ENCODE(princ->n_name_parts);
1186 for (loop = 0; loop < princ->n_name_parts; loop++)
1187 ENCODE_STR(princ->name_parts[loop]);
1188 ENCODE_STR(princ->realm);
1189
1190 princ = &token->k5->server;
1191 ENCODE(princ->n_name_parts);
1192 for (loop = 0; loop < princ->n_name_parts; loop++)
1193 ENCODE_STR(princ->name_parts[loop]);
1194 ENCODE_STR(princ->realm);
1195
1196 ENCODE(token->k5->session.tag);
1197 ENCODE_DATA(token->k5->session.data_len,
1198 token->k5->session.data);
1199
1200 ENCODE64(token->k5->authtime);
1201 ENCODE64(token->k5->starttime);
1202 ENCODE64(token->k5->endtime);
1203 ENCODE64(token->k5->renew_till);
1204 ENCODE(token->k5->is_skey);
1205 ENCODE(token->k5->flags);
1206
1207 ENCODE(token->k5->n_addresses);
1208 for (loop = 0; loop < token->k5->n_addresses; loop++) {
1209 ENCODE(token->k5->addresses[loop].tag);
1210 ENCODE_DATA(token->k5->addresses[loop].data_len,
1211 token->k5->addresses[loop].data);
1212 }
1213
1214 ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
1215 ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
1216
1217 ENCODE(token->k5->n_authdata);
1218 for (loop = 0; loop < token->k5->n_authdata; loop++) {
1219 ENCODE(token->k5->authdata[loop].tag);
1220 ENCODE_DATA(token->k5->authdata[loop].data_len,
1221 token->k5->authdata[loop].data);
1222 }
1223 break;
1224
1225 default:
1226 BUG();
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 fault:
1245 _leave(" = -EFAULT");
1246 return -EFAULT;
1247 }
1248