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bnxt_en: Expand bnxt_check_rings() to check all resources.
[linux-2.6/btrfs-unstable.git] / net / rxrpc / rxkad.c
blobc38b3a1de56c136f3e99096151635c226c5e02df
1 /* Kerberos-based RxRPC security
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
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <crypto/skcipher.h>
15 #include <linux/module.h>
16 #include <linux/net.h>
17 #include <linux/skbuff.h>
18 #include <linux/udp.h>
19 #include <linux/scatterlist.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 "ar-internal.h"
26
27 #define RXKAD_VERSION 2
28 #define MAXKRB5TICKETLEN 1024
29 #define RXKAD_TKT_TYPE_KERBEROS_V5 256
30 #define ANAME_SZ 40 /* size of authentication name */
31 #define INST_SZ 40 /* size of principal's instance */
32 #define REALM_SZ 40 /* size of principal's auth domain */
33 #define SNAME_SZ 40 /* size of service name */
34
35 struct rxkad_level1_hdr {
36 __be32 data_size; /* true data size (excluding padding) */
37 };
38
39 struct rxkad_level2_hdr {
40 __be32 data_size; /* true data size (excluding padding) */
41 __be32 checksum; /* decrypted data checksum */
42 };
43
44 /*
45 * this holds a pinned cipher so that keventd doesn't get called by the cipher
46 * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
47 * packets
48 */
49 static struct crypto_skcipher *rxkad_ci;
50 static DEFINE_MUTEX(rxkad_ci_mutex);
51
52 /*
53 * initialise connection security
54 */
55 static int rxkad_init_connection_security(struct rxrpc_connection *conn)
56 {
57 struct crypto_skcipher *ci;
58 struct rxrpc_key_token *token;
59 int ret;
60
61 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key));
62
63 token = conn->params.key->payload.data[0];
64 conn->security_ix = token->security_index;
65
66 ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
67 if (IS_ERR(ci)) {
68 _debug("no cipher");
69 ret = PTR_ERR(ci);
70 goto error;
71 }
72
73 if (crypto_skcipher_setkey(ci, token->kad->session_key,
74 sizeof(token->kad->session_key)) < 0)
75 BUG();
76
77 switch (conn->params.security_level) {
78 case RXRPC_SECURITY_PLAIN:
79 break;
80 case RXRPC_SECURITY_AUTH:
81 conn->size_align = 8;
82 conn->security_size = sizeof(struct rxkad_level1_hdr);
83 break;
84 case RXRPC_SECURITY_ENCRYPT:
85 conn->size_align = 8;
86 conn->security_size = sizeof(struct rxkad_level2_hdr);
87 break;
88 default:
89 ret = -EKEYREJECTED;
90 goto error;
91 }
92
93 conn->cipher = ci;
94 ret = 0;
95 error:
96 _leave(" = %d", ret);
97 return ret;
98 }
99
100 /*
101 * prime the encryption state with the invariant parts of a connection's
102 * description
103 */
104 static int rxkad_prime_packet_security(struct rxrpc_connection *conn)
105 {
106 struct rxrpc_key_token *token;
107 SKCIPHER_REQUEST_ON_STACK(req, conn->cipher);
108 struct scatterlist sg;
109 struct rxrpc_crypt iv;
110 __be32 *tmpbuf;
111 size_t tmpsize = 4 * sizeof(__be32);
112
113 _enter("");
114
115 if (!conn->params.key)
116 return 0;
117
118 tmpbuf = kmalloc(tmpsize, GFP_KERNEL);
119 if (!tmpbuf)
120 return -ENOMEM;
121
122 token = conn->params.key->payload.data[0];
123 memcpy(&iv, token->kad->session_key, sizeof(iv));
124
125 tmpbuf[0] = htonl(conn->proto.epoch);
126 tmpbuf[1] = htonl(conn->proto.cid);
127 tmpbuf[2] = 0;
128 tmpbuf[3] = htonl(conn->security_ix);
129
130 sg_init_one(&sg, tmpbuf, tmpsize);
131 skcipher_request_set_tfm(req, conn->cipher);
132 skcipher_request_set_callback(req, 0, NULL, NULL);
133 skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x);
134 crypto_skcipher_encrypt(req);
135 skcipher_request_zero(req);
136
137 memcpy(&conn->csum_iv, tmpbuf + 2, sizeof(conn->csum_iv));
138 kfree(tmpbuf);
139 _leave(" = 0");
140 return 0;
141 }
142
143 /*
144 * partially encrypt a packet (level 1 security)
145 */
146 static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
147 struct sk_buff *skb,
148 u32 data_size,
149 void *sechdr)
150 {
151 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
152 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
153 struct rxkad_level1_hdr hdr;
154 struct rxrpc_crypt iv;
155 struct scatterlist sg;
156 u16 check;
157
158 _enter("");
159
160 check = sp->hdr.seq ^ call->call_id;
161 data_size |= (u32)check << 16;
162
163 hdr.data_size = htonl(data_size);
164 memcpy(sechdr, &hdr, sizeof(hdr));
165
166 /* start the encryption afresh */
167 memset(&iv, 0, sizeof(iv));
168
169 sg_init_one(&sg, sechdr, 8);
170 skcipher_request_set_tfm(req, call->conn->cipher);
171 skcipher_request_set_callback(req, 0, NULL, NULL);
172 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
173 crypto_skcipher_encrypt(req);
174 skcipher_request_zero(req);
175
176 _leave(" = 0");
177 return 0;
178 }
179
180 /*
181 * wholly encrypt a packet (level 2 security)
182 */
183 static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
184 struct sk_buff *skb,
185 u32 data_size,
186 void *sechdr)
187 {
188 const struct rxrpc_key_token *token;
189 struct rxkad_level2_hdr rxkhdr;
190 struct rxrpc_skb_priv *sp;
191 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
192 struct rxrpc_crypt iv;
193 struct scatterlist sg[16];
194 struct sk_buff *trailer;
195 unsigned int len;
196 u16 check;
197 int nsg;
198 int err;
199
200 sp = rxrpc_skb(skb);
201
202 _enter("");
203
204 check = sp->hdr.seq ^ call->call_id;
205
206 rxkhdr.data_size = htonl(data_size | (u32)check << 16);
207 rxkhdr.checksum = 0;
208 memcpy(sechdr, &rxkhdr, sizeof(rxkhdr));
209
210 /* encrypt from the session key */
211 token = call->conn->params.key->payload.data[0];
212 memcpy(&iv, token->kad->session_key, sizeof(iv));
213
214 sg_init_one(&sg[0], sechdr, sizeof(rxkhdr));
215 skcipher_request_set_tfm(req, call->conn->cipher);
216 skcipher_request_set_callback(req, 0, NULL, NULL);
217 skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x);
218 crypto_skcipher_encrypt(req);
219
220 /* we want to encrypt the skbuff in-place */
221 nsg = skb_cow_data(skb, 0, &trailer);
222 err = -ENOMEM;
223 if (nsg < 0 || nsg > 16)
224 goto out;
225
226 len = data_size + call->conn->size_align - 1;
227 len &= ~(call->conn->size_align - 1);
228
229 sg_init_table(sg, nsg);
230 err = skb_to_sgvec(skb, sg, 0, len);
231 if (unlikely(err < 0))
232 goto out;
233 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
234 crypto_skcipher_encrypt(req);
235
236 _leave(" = 0");
237 err = 0;
238
239 out:
240 skcipher_request_zero(req);
241 return err;
242 }
243
244 /*
245 * checksum an RxRPC packet header
246 */
247 static int rxkad_secure_packet(struct rxrpc_call *call,
248 struct sk_buff *skb,
249 size_t data_size,
250 void *sechdr)
251 {
252 struct rxrpc_skb_priv *sp;
253 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
254 struct rxrpc_crypt iv;
255 struct scatterlist sg;
256 u32 x, y;
257 int ret;
258
259 sp = rxrpc_skb(skb);
260
261 _enter("{%d{%x}},{#%u},%zu,",
262 call->debug_id, key_serial(call->conn->params.key),
263 sp->hdr.seq, data_size);
264
265 if (!call->conn->cipher)
266 return 0;
267
268 ret = key_validate(call->conn->params.key);
269 if (ret < 0)
270 return ret;
271
272 /* continue encrypting from where we left off */
273 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
274
275 /* calculate the security checksum */
276 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
277 x |= sp->hdr.seq & 0x3fffffff;
278 call->crypto_buf[0] = htonl(call->call_id);
279 call->crypto_buf[1] = htonl(x);
280
281 sg_init_one(&sg, call->crypto_buf, 8);
282 skcipher_request_set_tfm(req, call->conn->cipher);
283 skcipher_request_set_callback(req, 0, NULL, NULL);
284 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
285 crypto_skcipher_encrypt(req);
286 skcipher_request_zero(req);
287
288 y = ntohl(call->crypto_buf[1]);
289 y = (y >> 16) & 0xffff;
290 if (y == 0)
291 y = 1; /* zero checksums are not permitted */
292 sp->hdr.cksum = y;
293
294 switch (call->conn->params.security_level) {
295 case RXRPC_SECURITY_PLAIN:
296 ret = 0;
297 break;
298 case RXRPC_SECURITY_AUTH:
299 ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr);
300 break;
301 case RXRPC_SECURITY_ENCRYPT:
302 ret = rxkad_secure_packet_encrypt(call, skb, data_size,
303 sechdr);
304 break;
305 default:
306 ret = -EPERM;
307 break;
308 }
309
310 _leave(" = %d [set %hx]", ret, y);
311 return ret;
312 }
313
314 /*
315 * decrypt partial encryption on a packet (level 1 security)
316 */
317 static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
318 unsigned int offset, unsigned int len,
319 rxrpc_seq_t seq)
320 {
321 struct rxkad_level1_hdr sechdr;
322 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
323 struct rxrpc_crypt iv;
324 struct scatterlist sg[16];
325 struct sk_buff *trailer;
326 bool aborted;
327 u32 data_size, buf;
328 u16 check;
329 int nsg, ret;
330
331 _enter("");
332
333 if (len < 8) {
334 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H",
335 RXKADSEALEDINCON);
336 goto protocol_error;
337 }
338
339 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
340 * directly into the target buffer.
341 */
342 nsg = skb_cow_data(skb, 0, &trailer);
343 if (nsg < 0 || nsg > 16)
344 goto nomem;
345
346 sg_init_table(sg, nsg);
347 ret = skb_to_sgvec(skb, sg, offset, 8);
348 if (unlikely(ret < 0))
349 return ret;
350
351 /* start the decryption afresh */
352 memset(&iv, 0, sizeof(iv));
353
354 skcipher_request_set_tfm(req, call->conn->cipher);
355 skcipher_request_set_callback(req, 0, NULL, NULL);
356 skcipher_request_set_crypt(req, sg, sg, 8, iv.x);
357 crypto_skcipher_decrypt(req);
358 skcipher_request_zero(req);
359
360 /* Extract the decrypted packet length */
361 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
362 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1",
363 RXKADDATALEN);
364 goto protocol_error;
365 }
366 offset += sizeof(sechdr);
367 len -= sizeof(sechdr);
368
369 buf = ntohl(sechdr.data_size);
370 data_size = buf & 0xffff;
371
372 check = buf >> 16;
373 check ^= seq ^ call->call_id;
374 check &= 0xffff;
375 if (check != 0) {
376 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C",
377 RXKADSEALEDINCON);
378 goto protocol_error;
379 }
380
381 if (data_size > len) {
382 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L",
383 RXKADDATALEN);
384 goto protocol_error;
385 }
386
387 _leave(" = 0 [dlen=%x]", data_size);
388 return 0;
389
390 protocol_error:
391 if (aborted)
392 rxrpc_send_abort_packet(call);
393 return -EPROTO;
394
395 nomem:
396 _leave(" = -ENOMEM");
397 return -ENOMEM;
398 }
399
400 /*
401 * wholly decrypt a packet (level 2 security)
402 */
403 static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
404 unsigned int offset, unsigned int len,
405 rxrpc_seq_t seq)
406 {
407 const struct rxrpc_key_token *token;
408 struct rxkad_level2_hdr sechdr;
409 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
410 struct rxrpc_crypt iv;
411 struct scatterlist _sg[4], *sg;
412 struct sk_buff *trailer;
413 bool aborted;
414 u32 data_size, buf;
415 u16 check;
416 int nsg, ret;
417
418 _enter(",{%d}", skb->len);
419
420 if (len < 8) {
421 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H",
422 RXKADSEALEDINCON);
423 goto protocol_error;
424 }
425
426 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
427 * directly into the target buffer.
428 */
429 nsg = skb_cow_data(skb, 0, &trailer);
430 if (nsg < 0)
431 goto nomem;
432
433 sg = _sg;
434 if (unlikely(nsg > 4)) {
435 sg = kmalloc(sizeof(*sg) * nsg, GFP_NOIO);
436 if (!sg)
437 goto nomem;
438 }
439
440 sg_init_table(sg, nsg);
441 ret = skb_to_sgvec(skb, sg, offset, len);
442 if (unlikely(ret < 0)) {
443 if (sg != _sg)
444 kfree(sg);
445 return ret;
446 }
447
448 /* decrypt from the session key */
449 token = call->conn->params.key->payload.data[0];
450 memcpy(&iv, token->kad->session_key, sizeof(iv));
451
452 skcipher_request_set_tfm(req, call->conn->cipher);
453 skcipher_request_set_callback(req, 0, NULL, NULL);
454 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
455 crypto_skcipher_decrypt(req);
456 skcipher_request_zero(req);
457 if (sg != _sg)
458 kfree(sg);
459
460 /* Extract the decrypted packet length */
461 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
462 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2",
463 RXKADDATALEN);
464 goto protocol_error;
465 }
466 offset += sizeof(sechdr);
467 len -= sizeof(sechdr);
468
469 buf = ntohl(sechdr.data_size);
470 data_size = buf & 0xffff;
471
472 check = buf >> 16;
473 check ^= seq ^ call->call_id;
474 check &= 0xffff;
475 if (check != 0) {
476 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C",
477 RXKADSEALEDINCON);
478 goto protocol_error;
479 }
480
481 if (data_size > len) {
482 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L",
483 RXKADDATALEN);
484 goto protocol_error;
485 }
486
487 _leave(" = 0 [dlen=%x]", data_size);
488 return 0;
489
490 protocol_error:
491 if (aborted)
492 rxrpc_send_abort_packet(call);
493 return -EPROTO;
494
495 nomem:
496 _leave(" = -ENOMEM");
497 return -ENOMEM;
498 }
499
500 /*
501 * Verify the security on a received packet or subpacket (if part of a
502 * jumbo packet).
503 */
504 static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
505 unsigned int offset, unsigned int len,
506 rxrpc_seq_t seq, u16 expected_cksum)
507 {
508 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
509 struct rxrpc_crypt iv;
510 struct scatterlist sg;
511 bool aborted;
512 u16 cksum;
513 u32 x, y;
514
515 _enter("{%d{%x}},{#%u}",
516 call->debug_id, key_serial(call->conn->params.key), seq);
517
518 if (!call->conn->cipher)
519 return 0;
520
521 /* continue encrypting from where we left off */
522 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
523
524 /* validate the security checksum */
525 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
526 x |= seq & 0x3fffffff;
527 call->crypto_buf[0] = htonl(call->call_id);
528 call->crypto_buf[1] = htonl(x);
529
530 sg_init_one(&sg, call->crypto_buf, 8);
531 skcipher_request_set_tfm(req, call->conn->cipher);
532 skcipher_request_set_callback(req, 0, NULL, NULL);
533 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
534 crypto_skcipher_encrypt(req);
535 skcipher_request_zero(req);
536
537 y = ntohl(call->crypto_buf[1]);
538 cksum = (y >> 16) & 0xffff;
539 if (cksum == 0)
540 cksum = 1; /* zero checksums are not permitted */
541
542 if (cksum != expected_cksum) {
543 aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK",
544 RXKADSEALEDINCON);
545 goto protocol_error;
546 }
547
548 switch (call->conn->params.security_level) {
549 case RXRPC_SECURITY_PLAIN:
550 return 0;
551 case RXRPC_SECURITY_AUTH:
552 return rxkad_verify_packet_1(call, skb, offset, len, seq);
553 case RXRPC_SECURITY_ENCRYPT:
554 return rxkad_verify_packet_2(call, skb, offset, len, seq);
555 default:
556 return -ENOANO;
557 }
558
559 protocol_error:
560 if (aborted)
561 rxrpc_send_abort_packet(call);
562 return -EPROTO;
563 }
564
565 /*
566 * Locate the data contained in a packet that was partially encrypted.
567 */
568 static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
569 unsigned int *_offset, unsigned int *_len)
570 {
571 struct rxkad_level1_hdr sechdr;
572
573 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
574 BUG();
575 *_offset += sizeof(sechdr);
576 *_len = ntohl(sechdr.data_size) & 0xffff;
577 }
578
579 /*
580 * Locate the data contained in a packet that was completely encrypted.
581 */
582 static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
583 unsigned int *_offset, unsigned int *_len)
584 {
585 struct rxkad_level2_hdr sechdr;
586
587 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
588 BUG();
589 *_offset += sizeof(sechdr);
590 *_len = ntohl(sechdr.data_size) & 0xffff;
591 }
592
593 /*
594 * Locate the data contained in an already decrypted packet.
595 */
596 static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
597 unsigned int *_offset, unsigned int *_len)
598 {
599 switch (call->conn->params.security_level) {
600 case RXRPC_SECURITY_AUTH:
601 rxkad_locate_data_1(call, skb, _offset, _len);
602 return;
603 case RXRPC_SECURITY_ENCRYPT:
604 rxkad_locate_data_2(call, skb, _offset, _len);
605 return;
606 default:
607 return;
608 }
609 }
610
611 /*
612 * issue a challenge
613 */
614 static int rxkad_issue_challenge(struct rxrpc_connection *conn)
615 {
616 struct rxkad_challenge challenge;
617 struct rxrpc_wire_header whdr;
618 struct msghdr msg;
619 struct kvec iov[2];
620 size_t len;
621 u32 serial;
622 int ret;
623
624 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
625
626 ret = key_validate(conn->params.key);
627 if (ret < 0)
628 return ret;
629
630 get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce));
631
632 challenge.version = htonl(2);
633 challenge.nonce = htonl(conn->security_nonce);
634 challenge.min_level = htonl(0);
635 challenge.__padding = 0;
636
637 msg.msg_name = &conn->params.peer->srx.transport;
638 msg.msg_namelen = conn->params.peer->srx.transport_len;
639 msg.msg_control = NULL;
640 msg.msg_controllen = 0;
641 msg.msg_flags = 0;
642
643 whdr.epoch = htonl(conn->proto.epoch);
644 whdr.cid = htonl(conn->proto.cid);
645 whdr.callNumber = 0;
646 whdr.seq = 0;
647 whdr.type = RXRPC_PACKET_TYPE_CHALLENGE;
648 whdr.flags = conn->out_clientflag;
649 whdr.userStatus = 0;
650 whdr.securityIndex = conn->security_ix;
651 whdr._rsvd = 0;
652 whdr.serviceId = htons(conn->service_id);
653
654 iov[0].iov_base = &whdr;
655 iov[0].iov_len = sizeof(whdr);
656 iov[1].iov_base = &challenge;
657 iov[1].iov_len = sizeof(challenge);
658
659 len = iov[0].iov_len + iov[1].iov_len;
660
661 serial = atomic_inc_return(&conn->serial);
662 whdr.serial = htonl(serial);
663 _proto("Tx CHALLENGE %%%u", serial);
664
665 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
666 if (ret < 0) {
667 _debug("sendmsg failed: %d", ret);
668 return -EAGAIN;
669 }
670
671 _leave(" = 0");
672 return 0;
673 }
674
675 /*
676 * send a Kerberos security response
677 */
678 static int rxkad_send_response(struct rxrpc_connection *conn,
679 struct rxrpc_host_header *hdr,
680 struct rxkad_response *resp,
681 const struct rxkad_key *s2)
682 {
683 struct rxrpc_wire_header whdr;
684 struct msghdr msg;
685 struct kvec iov[3];
686 size_t len;
687 u32 serial;
688 int ret;
689
690 _enter("");
691
692 msg.msg_name = &conn->params.peer->srx.transport;
693 msg.msg_namelen = conn->params.peer->srx.transport_len;
694 msg.msg_control = NULL;
695 msg.msg_controllen = 0;
696 msg.msg_flags = 0;
697
698 memset(&whdr, 0, sizeof(whdr));
699 whdr.epoch = htonl(hdr->epoch);
700 whdr.cid = htonl(hdr->cid);
701 whdr.type = RXRPC_PACKET_TYPE_RESPONSE;
702 whdr.flags = conn->out_clientflag;
703 whdr.securityIndex = hdr->securityIndex;
704 whdr.serviceId = htons(hdr->serviceId);
705
706 iov[0].iov_base = &whdr;
707 iov[0].iov_len = sizeof(whdr);
708 iov[1].iov_base = resp;
709 iov[1].iov_len = sizeof(*resp);
710 iov[2].iov_base = (void *)s2->ticket;
711 iov[2].iov_len = s2->ticket_len;
712
713 len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
714
715 serial = atomic_inc_return(&conn->serial);
716 whdr.serial = htonl(serial);
717 _proto("Tx RESPONSE %%%u", serial);
718
719 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len);
720 if (ret < 0) {
721 _debug("sendmsg failed: %d", ret);
722 return -EAGAIN;
723 }
724
725 _leave(" = 0");
726 return 0;
727 }
728
729 /*
730 * calculate the response checksum
731 */
732 static void rxkad_calc_response_checksum(struct rxkad_response *response)
733 {
734 u32 csum = 1000003;
735 int loop;
736 u8 *p = (u8 *) response;
737
738 for (loop = sizeof(*response); loop > 0; loop--)
739 csum = csum * 0x10204081 + *p++;
740
741 response->encrypted.checksum = htonl(csum);
742 }
743
744 /*
745 * encrypt the response packet
746 */
747 static void rxkad_encrypt_response(struct rxrpc_connection *conn,
748 struct rxkad_response *resp,
749 const struct rxkad_key *s2)
750 {
751 SKCIPHER_REQUEST_ON_STACK(req, conn->cipher);
752 struct rxrpc_crypt iv;
753 struct scatterlist sg[1];
754
755 /* continue encrypting from where we left off */
756 memcpy(&iv, s2->session_key, sizeof(iv));
757
758 sg_init_table(sg, 1);
759 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
760 skcipher_request_set_tfm(req, conn->cipher);
761 skcipher_request_set_callback(req, 0, NULL, NULL);
762 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
763 crypto_skcipher_encrypt(req);
764 skcipher_request_zero(req);
765 }
766
767 /*
768 * respond to a challenge packet
769 */
770 static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
771 struct sk_buff *skb,
772 u32 *_abort_code)
773 {
774 const struct rxrpc_key_token *token;
775 struct rxkad_challenge challenge;
776 struct rxkad_response resp
777 __attribute__((aligned(8))); /* must be aligned for crypto */
778 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
779 const char *eproto;
780 u32 version, nonce, min_level, abort_code;
781 int ret;
782
783 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
784
785 eproto = tracepoint_string("chall_no_key");
786 abort_code = RX_PROTOCOL_ERROR;
787 if (!conn->params.key)
788 goto protocol_error;
789
790 abort_code = RXKADEXPIRED;
791 ret = key_validate(conn->params.key);
792 if (ret < 0)
793 goto other_error;
794
795 eproto = tracepoint_string("chall_short");
796 abort_code = RXKADPACKETSHORT;
797 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
798 &challenge, sizeof(challenge)) < 0)
799 goto protocol_error;
800
801 version = ntohl(challenge.version);
802 nonce = ntohl(challenge.nonce);
803 min_level = ntohl(challenge.min_level);
804
805 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
806 sp->hdr.serial, version, nonce, min_level);
807
808 eproto = tracepoint_string("chall_ver");
809 abort_code = RXKADINCONSISTENCY;
810 if (version != RXKAD_VERSION)
811 goto protocol_error;
812
813 abort_code = RXKADLEVELFAIL;
814 ret = -EACCES;
815 if (conn->params.security_level < min_level)
816 goto other_error;
817
818 token = conn->params.key->payload.data[0];
819
820 /* build the response packet */
821 memset(&resp, 0, sizeof(resp));
822
823 resp.version = htonl(RXKAD_VERSION);
824 resp.encrypted.epoch = htonl(conn->proto.epoch);
825 resp.encrypted.cid = htonl(conn->proto.cid);
826 resp.encrypted.securityIndex = htonl(conn->security_ix);
827 resp.encrypted.inc_nonce = htonl(nonce + 1);
828 resp.encrypted.level = htonl(conn->params.security_level);
829 resp.kvno = htonl(token->kad->kvno);
830 resp.ticket_len = htonl(token->kad->ticket_len);
831
832 resp.encrypted.call_id[0] = htonl(conn->channels[0].call_counter);
833 resp.encrypted.call_id[1] = htonl(conn->channels[1].call_counter);
834 resp.encrypted.call_id[2] = htonl(conn->channels[2].call_counter);
835 resp.encrypted.call_id[3] = htonl(conn->channels[3].call_counter);
836
837 /* calculate the response checksum and then do the encryption */
838 rxkad_calc_response_checksum(&resp);
839 rxkad_encrypt_response(conn, &resp, token->kad);
840 return rxkad_send_response(conn, &sp->hdr, &resp, token->kad);
841
842 protocol_error:
843 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
844 ret = -EPROTO;
845 other_error:
846 *_abort_code = abort_code;
847 return ret;
848 }
849
850 /*
851 * decrypt the kerberos IV ticket in the response
852 */
853 static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
854 struct sk_buff *skb,
855 void *ticket, size_t ticket_len,
856 struct rxrpc_crypt *_session_key,
857 time64_t *_expiry,
858 u32 *_abort_code)
859 {
860 struct skcipher_request *req;
861 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
862 struct rxrpc_crypt iv, key;
863 struct scatterlist sg[1];
864 struct in_addr addr;
865 unsigned int life;
866 const char *eproto;
867 time64_t issue, now;
868 bool little_endian;
869 int ret;
870 u32 abort_code;
871 u8 *p, *q, *name, *end;
872
873 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
874
875 *_expiry = 0;
876
877 ret = key_validate(conn->server_key);
878 if (ret < 0) {
879 switch (ret) {
880 case -EKEYEXPIRED:
881 abort_code = RXKADEXPIRED;
882 goto other_error;
883 default:
884 abort_code = RXKADNOAUTH;
885 goto other_error;
886 }
887 }
888
889 ASSERT(conn->server_key->payload.data[0] != NULL);
890 ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
891
892 memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
893
894 ret = -ENOMEM;
895 req = skcipher_request_alloc(conn->server_key->payload.data[0],
896 GFP_NOFS);
897 if (!req)
898 goto temporary_error;
899
900 sg_init_one(&sg[0], ticket, ticket_len);
901 skcipher_request_set_callback(req, 0, NULL, NULL);
902 skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x);
903 crypto_skcipher_decrypt(req);
904 skcipher_request_free(req);
905
906 p = ticket;
907 end = p + ticket_len;
908
909 #define Z(field) \
910 ({ \
911 u8 *__str = p; \
912 eproto = tracepoint_string("rxkad_bad_"#field); \
913 q = memchr(p, 0, end - p); \
914 if (!q || q - p > (field##_SZ)) \
915 goto bad_ticket; \
916 for (; p < q; p++) \
917 if (!isprint(*p)) \
918 goto bad_ticket; \
919 p++; \
920 __str; \
921 })
922
923 /* extract the ticket flags */
924 _debug("KIV FLAGS: %x", *p);
925 little_endian = *p & 1;
926 p++;
927
928 /* extract the authentication name */
929 name = Z(ANAME);
930 _debug("KIV ANAME: %s", name);
931
932 /* extract the principal's instance */
933 name = Z(INST);
934 _debug("KIV INST : %s", name);
935
936 /* extract the principal's authentication domain */
937 name = Z(REALM);
938 _debug("KIV REALM: %s", name);
939
940 eproto = tracepoint_string("rxkad_bad_len");
941 if (end - p < 4 + 8 + 4 + 2)
942 goto bad_ticket;
943
944 /* get the IPv4 address of the entity that requested the ticket */
945 memcpy(&addr, p, sizeof(addr));
946 p += 4;
947 _debug("KIV ADDR : %pI4", &addr);
948
949 /* get the session key from the ticket */
950 memcpy(&key, p, sizeof(key));
951 p += 8;
952 _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
953 memcpy(_session_key, &key, sizeof(key));
954
955 /* get the ticket's lifetime */
956 life = *p++ * 5 * 60;
957 _debug("KIV LIFE : %u", life);
958
959 /* get the issue time of the ticket */
960 if (little_endian) {
961 __le32 stamp;
962 memcpy(&stamp, p, 4);
963 issue = rxrpc_u32_to_time64(le32_to_cpu(stamp));
964 } else {
965 __be32 stamp;
966 memcpy(&stamp, p, 4);
967 issue = rxrpc_u32_to_time64(be32_to_cpu(stamp));
968 }
969 p += 4;
970 now = ktime_get_real_seconds();
971 _debug("KIV ISSUE: %llx [%llx]", issue, now);
972
973 /* check the ticket is in date */
974 if (issue > now) {
975 abort_code = RXKADNOAUTH;
976 ret = -EKEYREJECTED;
977 goto other_error;
978 }
979
980 if (issue < now - life) {
981 abort_code = RXKADEXPIRED;
982 ret = -EKEYEXPIRED;
983 goto other_error;
984 }
985
986 *_expiry = issue + life;
987
988 /* get the service name */
989 name = Z(SNAME);
990 _debug("KIV SNAME: %s", name);
991
992 /* get the service instance name */
993 name = Z(INST);
994 _debug("KIV SINST: %s", name);
995 return 0;
996
997 bad_ticket:
998 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
999 abort_code = RXKADBADTICKET;
1000 ret = -EPROTO;
1001 other_error:
1002 *_abort_code = abort_code;
1003 return ret;
1004 temporary_error:
1005 return ret;
1006 }
1007
1008 /*
1009 * decrypt the response packet
1010 */
1011 static void rxkad_decrypt_response(struct rxrpc_connection *conn,
1012 struct rxkad_response *resp,
1013 const struct rxrpc_crypt *session_key)
1014 {
1015 SKCIPHER_REQUEST_ON_STACK(req, rxkad_ci);
1016 struct scatterlist sg[1];
1017 struct rxrpc_crypt iv;
1018
1019 _enter(",,%08x%08x",
1020 ntohl(session_key->n[0]), ntohl(session_key->n[1]));
1021
1022 ASSERT(rxkad_ci != NULL);
1023
1024 mutex_lock(&rxkad_ci_mutex);
1025 if (crypto_skcipher_setkey(rxkad_ci, session_key->x,
1026 sizeof(*session_key)) < 0)
1027 BUG();
1028
1029 memcpy(&iv, session_key, sizeof(iv));
1030
1031 sg_init_table(sg, 1);
1032 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
1033 skcipher_request_set_tfm(req, rxkad_ci);
1034 skcipher_request_set_callback(req, 0, NULL, NULL);
1035 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
1036 crypto_skcipher_decrypt(req);
1037 skcipher_request_zero(req);
1038
1039 mutex_unlock(&rxkad_ci_mutex);
1040
1041 _leave("");
1042 }
1043
1044 /*
1045 * verify a response
1046 */
1047 static int rxkad_verify_response(struct rxrpc_connection *conn,
1048 struct sk_buff *skb,
1049 u32 *_abort_code)
1050 {
1051 struct rxkad_response response
1052 __attribute__((aligned(8))); /* must be aligned for crypto */
1053 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1054 struct rxrpc_crypt session_key;
1055 const char *eproto;
1056 time64_t expiry;
1057 void *ticket;
1058 u32 abort_code, version, kvno, ticket_len, level;
1059 __be32 csum;
1060 int ret, i;
1061
1062 _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
1063
1064 eproto = tracepoint_string("rxkad_rsp_short");
1065 abort_code = RXKADPACKETSHORT;
1066 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1067 &response, sizeof(response)) < 0)
1068 goto protocol_error;
1069 if (!pskb_pull(skb, sizeof(response)))
1070 BUG();
1071
1072 version = ntohl(response.version);
1073 ticket_len = ntohl(response.ticket_len);
1074 kvno = ntohl(response.kvno);
1075 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1076 sp->hdr.serial, version, kvno, ticket_len);
1077
1078 eproto = tracepoint_string("rxkad_rsp_ver");
1079 abort_code = RXKADINCONSISTENCY;
1080 if (version != RXKAD_VERSION)
1081 goto protocol_error;
1082
1083 eproto = tracepoint_string("rxkad_rsp_tktlen");
1084 abort_code = RXKADTICKETLEN;
1085 if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
1086 goto protocol_error;
1087
1088 eproto = tracepoint_string("rxkad_rsp_unkkey");
1089 abort_code = RXKADUNKNOWNKEY;
1090 if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
1091 goto protocol_error;
1092
1093 /* extract the kerberos ticket and decrypt and decode it */
1094 ret = -ENOMEM;
1095 ticket = kmalloc(ticket_len, GFP_NOFS);
1096 if (!ticket)
1097 goto temporary_error;
1098
1099 eproto = tracepoint_string("rxkad_tkt_short");
1100 abort_code = RXKADPACKETSHORT;
1101 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1102 ticket, ticket_len) < 0)
1103 goto protocol_error_free;
1104
1105 ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key,
1106 &expiry, _abort_code);
1107 if (ret < 0)
1108 goto temporary_error_free;
1109
1110 /* use the session key from inside the ticket to decrypt the
1111 * response */
1112 rxkad_decrypt_response(conn, &response, &session_key);
1113
1114 eproto = tracepoint_string("rxkad_rsp_param");
1115 abort_code = RXKADSEALEDINCON;
1116 if (ntohl(response.encrypted.epoch) != conn->proto.epoch)
1117 goto protocol_error_free;
1118 if (ntohl(response.encrypted.cid) != conn->proto.cid)
1119 goto protocol_error_free;
1120 if (ntohl(response.encrypted.securityIndex) != conn->security_ix)
1121 goto protocol_error_free;
1122 csum = response.encrypted.checksum;
1123 response.encrypted.checksum = 0;
1124 rxkad_calc_response_checksum(&response);
1125 eproto = tracepoint_string("rxkad_rsp_csum");
1126 if (response.encrypted.checksum != csum)
1127 goto protocol_error_free;
1128
1129 spin_lock(&conn->channel_lock);
1130 for (i = 0; i < RXRPC_MAXCALLS; i++) {
1131 struct rxrpc_call *call;
1132 u32 call_id = ntohl(response.encrypted.call_id[i]);
1133
1134 eproto = tracepoint_string("rxkad_rsp_callid");
1135 if (call_id > INT_MAX)
1136 goto protocol_error_unlock;
1137
1138 eproto = tracepoint_string("rxkad_rsp_callctr");
1139 if (call_id < conn->channels[i].call_counter)
1140 goto protocol_error_unlock;
1141
1142 eproto = tracepoint_string("rxkad_rsp_callst");
1143 if (call_id > conn->channels[i].call_counter) {
1144 call = rcu_dereference_protected(
1145 conn->channels[i].call,
1146 lockdep_is_held(&conn->channel_lock));
1147 if (call && call->state < RXRPC_CALL_COMPLETE)
1148 goto protocol_error_unlock;
1149 conn->channels[i].call_counter = call_id;
1150 }
1151 }
1152 spin_unlock(&conn->channel_lock);
1153
1154 eproto = tracepoint_string("rxkad_rsp_seq");
1155 abort_code = RXKADOUTOFSEQUENCE;
1156 if (ntohl(response.encrypted.inc_nonce) != conn->security_nonce + 1)
1157 goto protocol_error_free;
1158
1159 eproto = tracepoint_string("rxkad_rsp_level");
1160 abort_code = RXKADLEVELFAIL;
1161 level = ntohl(response.encrypted.level);
1162 if (level > RXRPC_SECURITY_ENCRYPT)
1163 goto protocol_error_free;
1164 conn->params.security_level = level;
1165
1166 /* create a key to hold the security data and expiration time - after
1167 * this the connection security can be handled in exactly the same way
1168 * as for a client connection */
1169 ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
1170 if (ret < 0)
1171 goto temporary_error_free;
1172
1173 kfree(ticket);
1174 _leave(" = 0");
1175 return 0;
1176
1177 protocol_error_unlock:
1178 spin_unlock(&conn->channel_lock);
1179 protocol_error_free:
1180 kfree(ticket);
1181 protocol_error:
1182 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1183 *_abort_code = abort_code;
1184 return -EPROTO;
1185
1186 temporary_error_free:
1187 kfree(ticket);
1188 temporary_error:
1189 /* Ignore the response packet if we got a temporary error such as
1190 * ENOMEM. We just want to send the challenge again. Note that we
1191 * also come out this way if the ticket decryption fails.
1192 */
1193 return ret;
1194 }
1195
1196 /*
1197 * clear the connection security
1198 */
1199 static void rxkad_clear(struct rxrpc_connection *conn)
1200 {
1201 _enter("");
1202
1203 if (conn->cipher)
1204 crypto_free_skcipher(conn->cipher);
1205 }
1206
1207 /*
1208 * Initialise the rxkad security service.
1209 */
1210 static int rxkad_init(void)
1211 {
1212 /* pin the cipher we need so that the crypto layer doesn't invoke
1213 * keventd to go get it */
1214 rxkad_ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
1215 return PTR_ERR_OR_ZERO(rxkad_ci);
1216 }
1217
1218 /*
1219 * Clean up the rxkad security service.
1220 */
1221 static void rxkad_exit(void)
1222 {
1223 if (rxkad_ci)
1224 crypto_free_skcipher(rxkad_ci);
1225 }
1226
1227 /*
1228 * RxRPC Kerberos-based security
1229 */
1230 const struct rxrpc_security rxkad = {
1231 .name = "rxkad",
1232 .security_index = RXRPC_SECURITY_RXKAD,
1233 .init = rxkad_init,
1234 .exit = rxkad_exit,
1235 .init_connection_security = rxkad_init_connection_security,
1236 .prime_packet_security = rxkad_prime_packet_security,
1237 .secure_packet = rxkad_secure_packet,
1238 .verify_packet = rxkad_verify_packet,
1239 .locate_data = rxkad_locate_data,
1240 .issue_challenge = rxkad_issue_challenge,
1241 .respond_to_challenge = rxkad_respond_to_challenge,
1242 .verify_response = rxkad_verify_response,
1243 .clear = rxkad_clear,
1244 };
(deprecated) Btrfs devel tree