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staging: ks7010: replace cast type in assignment in hostif_sme_set_pmksa
[linux/fpc-iii.git] / net / rxrpc / rxkad.c
blob588fea0dd3627e5ea6515963d9eabebca603831e
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 conn->params.peer->last_tx_at = ktime_get_real();
672 _leave(" = 0");
673 return 0;
674 }
675
676 /*
677 * send a Kerberos security response
678 */
679 static int rxkad_send_response(struct rxrpc_connection *conn,
680 struct rxrpc_host_header *hdr,
681 struct rxkad_response *resp,
682 const struct rxkad_key *s2)
683 {
684 struct rxrpc_wire_header whdr;
685 struct msghdr msg;
686 struct kvec iov[3];
687 size_t len;
688 u32 serial;
689 int ret;
690
691 _enter("");
692
693 msg.msg_name = &conn->params.peer->srx.transport;
694 msg.msg_namelen = conn->params.peer->srx.transport_len;
695 msg.msg_control = NULL;
696 msg.msg_controllen = 0;
697 msg.msg_flags = 0;
698
699 memset(&whdr, 0, sizeof(whdr));
700 whdr.epoch = htonl(hdr->epoch);
701 whdr.cid = htonl(hdr->cid);
702 whdr.type = RXRPC_PACKET_TYPE_RESPONSE;
703 whdr.flags = conn->out_clientflag;
704 whdr.securityIndex = hdr->securityIndex;
705 whdr.serviceId = htons(hdr->serviceId);
706
707 iov[0].iov_base = &whdr;
708 iov[0].iov_len = sizeof(whdr);
709 iov[1].iov_base = resp;
710 iov[1].iov_len = sizeof(*resp);
711 iov[2].iov_base = (void *)s2->ticket;
712 iov[2].iov_len = s2->ticket_len;
713
714 len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
715
716 serial = atomic_inc_return(&conn->serial);
717 whdr.serial = htonl(serial);
718 _proto("Tx RESPONSE %%%u", serial);
719
720 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len);
721 if (ret < 0) {
722 _debug("sendmsg failed: %d", ret);
723 return -EAGAIN;
724 }
725
726 conn->params.peer->last_tx_at = ktime_get_real();
727 _leave(" = 0");
728 return 0;
729 }
730
731 /*
732 * calculate the response checksum
733 */
734 static void rxkad_calc_response_checksum(struct rxkad_response *response)
735 {
736 u32 csum = 1000003;
737 int loop;
738 u8 *p = (u8 *) response;
739
740 for (loop = sizeof(*response); loop > 0; loop--)
741 csum = csum * 0x10204081 + *p++;
742
743 response->encrypted.checksum = htonl(csum);
744 }
745
746 /*
747 * encrypt the response packet
748 */
749 static void rxkad_encrypt_response(struct rxrpc_connection *conn,
750 struct rxkad_response *resp,
751 const struct rxkad_key *s2)
752 {
753 SKCIPHER_REQUEST_ON_STACK(req, conn->cipher);
754 struct rxrpc_crypt iv;
755 struct scatterlist sg[1];
756
757 /* continue encrypting from where we left off */
758 memcpy(&iv, s2->session_key, sizeof(iv));
759
760 sg_init_table(sg, 1);
761 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
762 skcipher_request_set_tfm(req, conn->cipher);
763 skcipher_request_set_callback(req, 0, NULL, NULL);
764 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
765 crypto_skcipher_encrypt(req);
766 skcipher_request_zero(req);
767 }
768
769 /*
770 * respond to a challenge packet
771 */
772 static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
773 struct sk_buff *skb,
774 u32 *_abort_code)
775 {
776 const struct rxrpc_key_token *token;
777 struct rxkad_challenge challenge;
778 struct rxkad_response *resp;
779 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
780 const char *eproto;
781 u32 version, nonce, min_level, abort_code;
782 int ret;
783
784 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
785
786 eproto = tracepoint_string("chall_no_key");
787 abort_code = RX_PROTOCOL_ERROR;
788 if (!conn->params.key)
789 goto protocol_error;
790
791 abort_code = RXKADEXPIRED;
792 ret = key_validate(conn->params.key);
793 if (ret < 0)
794 goto other_error;
795
796 eproto = tracepoint_string("chall_short");
797 abort_code = RXKADPACKETSHORT;
798 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
799 &challenge, sizeof(challenge)) < 0)
800 goto protocol_error;
801
802 version = ntohl(challenge.version);
803 nonce = ntohl(challenge.nonce);
804 min_level = ntohl(challenge.min_level);
805
806 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
807 sp->hdr.serial, version, nonce, min_level);
808
809 eproto = tracepoint_string("chall_ver");
810 abort_code = RXKADINCONSISTENCY;
811 if (version != RXKAD_VERSION)
812 goto protocol_error;
813
814 abort_code = RXKADLEVELFAIL;
815 ret = -EACCES;
816 if (conn->params.security_level < min_level)
817 goto other_error;
818
819 token = conn->params.key->payload.data[0];
820
821 /* build the response packet */
822 resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
823 if (!resp)
824 return -ENOMEM;
825
826 resp->version = htonl(RXKAD_VERSION);
827 resp->encrypted.epoch = htonl(conn->proto.epoch);
828 resp->encrypted.cid = htonl(conn->proto.cid);
829 resp->encrypted.securityIndex = htonl(conn->security_ix);
830 resp->encrypted.inc_nonce = htonl(nonce + 1);
831 resp->encrypted.level = htonl(conn->params.security_level);
832 resp->kvno = htonl(token->kad->kvno);
833 resp->ticket_len = htonl(token->kad->ticket_len);
834 resp->encrypted.call_id[0] = htonl(conn->channels[0].call_counter);
835 resp->encrypted.call_id[1] = htonl(conn->channels[1].call_counter);
836 resp->encrypted.call_id[2] = htonl(conn->channels[2].call_counter);
837 resp->encrypted.call_id[3] = htonl(conn->channels[3].call_counter);
838
839 /* calculate the response checksum and then do the encryption */
840 rxkad_calc_response_checksum(resp);
841 rxkad_encrypt_response(conn, resp, token->kad);
842 ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad);
843 kfree(resp);
844 return ret;
845
846 protocol_error:
847 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
848 ret = -EPROTO;
849 other_error:
850 *_abort_code = abort_code;
851 return ret;
852 }
853
854 /*
855 * decrypt the kerberos IV ticket in the response
856 */
857 static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
858 struct sk_buff *skb,
859 void *ticket, size_t ticket_len,
860 struct rxrpc_crypt *_session_key,
861 time64_t *_expiry,
862 u32 *_abort_code)
863 {
864 struct skcipher_request *req;
865 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
866 struct rxrpc_crypt iv, key;
867 struct scatterlist sg[1];
868 struct in_addr addr;
869 unsigned int life;
870 const char *eproto;
871 time64_t issue, now;
872 bool little_endian;
873 int ret;
874 u32 abort_code;
875 u8 *p, *q, *name, *end;
876
877 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
878
879 *_expiry = 0;
880
881 ret = key_validate(conn->server_key);
882 if (ret < 0) {
883 switch (ret) {
884 case -EKEYEXPIRED:
885 abort_code = RXKADEXPIRED;
886 goto other_error;
887 default:
888 abort_code = RXKADNOAUTH;
889 goto other_error;
890 }
891 }
892
893 ASSERT(conn->server_key->payload.data[0] != NULL);
894 ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
895
896 memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
897
898 ret = -ENOMEM;
899 req = skcipher_request_alloc(conn->server_key->payload.data[0],
900 GFP_NOFS);
901 if (!req)
902 goto temporary_error;
903
904 sg_init_one(&sg[0], ticket, ticket_len);
905 skcipher_request_set_callback(req, 0, NULL, NULL);
906 skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x);
907 crypto_skcipher_decrypt(req);
908 skcipher_request_free(req);
909
910 p = ticket;
911 end = p + ticket_len;
912
913 #define Z(field) \
914 ({ \
915 u8 *__str = p; \
916 eproto = tracepoint_string("rxkad_bad_"#field); \
917 q = memchr(p, 0, end - p); \
918 if (!q || q - p > (field##_SZ)) \
919 goto bad_ticket; \
920 for (; p < q; p++) \
921 if (!isprint(*p)) \
922 goto bad_ticket; \
923 p++; \
924 __str; \
925 })
926
927 /* extract the ticket flags */
928 _debug("KIV FLAGS: %x", *p);
929 little_endian = *p & 1;
930 p++;
931
932 /* extract the authentication name */
933 name = Z(ANAME);
934 _debug("KIV ANAME: %s", name);
935
936 /* extract the principal's instance */
937 name = Z(INST);
938 _debug("KIV INST : %s", name);
939
940 /* extract the principal's authentication domain */
941 name = Z(REALM);
942 _debug("KIV REALM: %s", name);
943
944 eproto = tracepoint_string("rxkad_bad_len");
945 if (end - p < 4 + 8 + 4 + 2)
946 goto bad_ticket;
947
948 /* get the IPv4 address of the entity that requested the ticket */
949 memcpy(&addr, p, sizeof(addr));
950 p += 4;
951 _debug("KIV ADDR : %pI4", &addr);
952
953 /* get the session key from the ticket */
954 memcpy(&key, p, sizeof(key));
955 p += 8;
956 _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
957 memcpy(_session_key, &key, sizeof(key));
958
959 /* get the ticket's lifetime */
960 life = *p++ * 5 * 60;
961 _debug("KIV LIFE : %u", life);
962
963 /* get the issue time of the ticket */
964 if (little_endian) {
965 __le32 stamp;
966 memcpy(&stamp, p, 4);
967 issue = rxrpc_u32_to_time64(le32_to_cpu(stamp));
968 } else {
969 __be32 stamp;
970 memcpy(&stamp, p, 4);
971 issue = rxrpc_u32_to_time64(be32_to_cpu(stamp));
972 }
973 p += 4;
974 now = ktime_get_real_seconds();
975 _debug("KIV ISSUE: %llx [%llx]", issue, now);
976
977 /* check the ticket is in date */
978 if (issue > now) {
979 abort_code = RXKADNOAUTH;
980 ret = -EKEYREJECTED;
981 goto other_error;
982 }
983
984 if (issue < now - life) {
985 abort_code = RXKADEXPIRED;
986 ret = -EKEYEXPIRED;
987 goto other_error;
988 }
989
990 *_expiry = issue + life;
991
992 /* get the service name */
993 name = Z(SNAME);
994 _debug("KIV SNAME: %s", name);
995
996 /* get the service instance name */
997 name = Z(INST);
998 _debug("KIV SINST: %s", name);
999 return 0;
1000
1001 bad_ticket:
1002 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1003 abort_code = RXKADBADTICKET;
1004 ret = -EPROTO;
1005 other_error:
1006 *_abort_code = abort_code;
1007 return ret;
1008 temporary_error:
1009 return ret;
1010 }
1011
1012 /*
1013 * decrypt the response packet
1014 */
1015 static void rxkad_decrypt_response(struct rxrpc_connection *conn,
1016 struct rxkad_response *resp,
1017 const struct rxrpc_crypt *session_key)
1018 {
1019 SKCIPHER_REQUEST_ON_STACK(req, rxkad_ci);
1020 struct scatterlist sg[1];
1021 struct rxrpc_crypt iv;
1022
1023 _enter(",,%08x%08x",
1024 ntohl(session_key->n[0]), ntohl(session_key->n[1]));
1025
1026 ASSERT(rxkad_ci != NULL);
1027
1028 mutex_lock(&rxkad_ci_mutex);
1029 if (crypto_skcipher_setkey(rxkad_ci, session_key->x,
1030 sizeof(*session_key)) < 0)
1031 BUG();
1032
1033 memcpy(&iv, session_key, sizeof(iv));
1034
1035 sg_init_table(sg, 1);
1036 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
1037 skcipher_request_set_tfm(req, rxkad_ci);
1038 skcipher_request_set_callback(req, 0, NULL, NULL);
1039 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
1040 crypto_skcipher_decrypt(req);
1041 skcipher_request_zero(req);
1042
1043 mutex_unlock(&rxkad_ci_mutex);
1044
1045 _leave("");
1046 }
1047
1048 /*
1049 * verify a response
1050 */
1051 static int rxkad_verify_response(struct rxrpc_connection *conn,
1052 struct sk_buff *skb,
1053 u32 *_abort_code)
1054 {
1055 struct rxkad_response *response;
1056 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1057 struct rxrpc_crypt session_key;
1058 const char *eproto;
1059 time64_t expiry;
1060 void *ticket;
1061 u32 abort_code, version, kvno, ticket_len, level;
1062 __be32 csum;
1063 int ret, i;
1064
1065 _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
1066
1067 ret = -ENOMEM;
1068 response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
1069 if (!response)
1070 goto temporary_error;
1071
1072 eproto = tracepoint_string("rxkad_rsp_short");
1073 abort_code = RXKADPACKETSHORT;
1074 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1075 response, sizeof(*response)) < 0)
1076 goto protocol_error;
1077 if (!pskb_pull(skb, sizeof(*response)))
1078 BUG();
1079
1080 version = ntohl(response->version);
1081 ticket_len = ntohl(response->ticket_len);
1082 kvno = ntohl(response->kvno);
1083 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1084 sp->hdr.serial, version, kvno, ticket_len);
1085
1086 eproto = tracepoint_string("rxkad_rsp_ver");
1087 abort_code = RXKADINCONSISTENCY;
1088 if (version != RXKAD_VERSION)
1089 goto protocol_error;
1090
1091 eproto = tracepoint_string("rxkad_rsp_tktlen");
1092 abort_code = RXKADTICKETLEN;
1093 if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
1094 goto protocol_error;
1095
1096 eproto = tracepoint_string("rxkad_rsp_unkkey");
1097 abort_code = RXKADUNKNOWNKEY;
1098 if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
1099 goto protocol_error;
1100
1101 /* extract the kerberos ticket and decrypt and decode it */
1102 ret = -ENOMEM;
1103 ticket = kmalloc(ticket_len, GFP_NOFS);
1104 if (!ticket)
1105 goto temporary_error;
1106
1107 eproto = tracepoint_string("rxkad_tkt_short");
1108 abort_code = RXKADPACKETSHORT;
1109 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1110 ticket, ticket_len) < 0)
1111 goto protocol_error_free;
1112
1113 ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key,
1114 &expiry, _abort_code);
1115 if (ret < 0)
1116 goto temporary_error_free_resp;
1117
1118 /* use the session key from inside the ticket to decrypt the
1119 * response */
1120 rxkad_decrypt_response(conn, response, &session_key);
1121
1122 eproto = tracepoint_string("rxkad_rsp_param");
1123 abort_code = RXKADSEALEDINCON;
1124 if (ntohl(response->encrypted.epoch) != conn->proto.epoch)
1125 goto protocol_error_free;
1126 if (ntohl(response->encrypted.cid) != conn->proto.cid)
1127 goto protocol_error_free;
1128 if (ntohl(response->encrypted.securityIndex) != conn->security_ix)
1129 goto protocol_error_free;
1130 csum = response->encrypted.checksum;
1131 response->encrypted.checksum = 0;
1132 rxkad_calc_response_checksum(response);
1133 eproto = tracepoint_string("rxkad_rsp_csum");
1134 if (response->encrypted.checksum != csum)
1135 goto protocol_error_free;
1136
1137 spin_lock(&conn->channel_lock);
1138 for (i = 0; i < RXRPC_MAXCALLS; i++) {
1139 struct rxrpc_call *call;
1140 u32 call_id = ntohl(response->encrypted.call_id[i]);
1141
1142 eproto = tracepoint_string("rxkad_rsp_callid");
1143 if (call_id > INT_MAX)
1144 goto protocol_error_unlock;
1145
1146 eproto = tracepoint_string("rxkad_rsp_callctr");
1147 if (call_id < conn->channels[i].call_counter)
1148 goto protocol_error_unlock;
1149
1150 eproto = tracepoint_string("rxkad_rsp_callst");
1151 if (call_id > conn->channels[i].call_counter) {
1152 call = rcu_dereference_protected(
1153 conn->channels[i].call,
1154 lockdep_is_held(&conn->channel_lock));
1155 if (call && call->state < RXRPC_CALL_COMPLETE)
1156 goto protocol_error_unlock;
1157 conn->channels[i].call_counter = call_id;
1158 }
1159 }
1160 spin_unlock(&conn->channel_lock);
1161
1162 eproto = tracepoint_string("rxkad_rsp_seq");
1163 abort_code = RXKADOUTOFSEQUENCE;
1164 if (ntohl(response->encrypted.inc_nonce) != conn->security_nonce + 1)
1165 goto protocol_error_free;
1166
1167 eproto = tracepoint_string("rxkad_rsp_level");
1168 abort_code = RXKADLEVELFAIL;
1169 level = ntohl(response->encrypted.level);
1170 if (level > RXRPC_SECURITY_ENCRYPT)
1171 goto protocol_error_free;
1172 conn->params.security_level = level;
1173
1174 /* create a key to hold the security data and expiration time - after
1175 * this the connection security can be handled in exactly the same way
1176 * as for a client connection */
1177 ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
1178 if (ret < 0)
1179 goto temporary_error_free_ticket;
1180
1181 kfree(ticket);
1182 kfree(response);
1183 _leave(" = 0");
1184 return 0;
1185
1186 protocol_error_unlock:
1187 spin_unlock(&conn->channel_lock);
1188 protocol_error_free:
1189 kfree(ticket);
1190 protocol_error:
1191 kfree(response);
1192 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1193 *_abort_code = abort_code;
1194 return -EPROTO;
1195
1196 temporary_error_free_ticket:
1197 kfree(ticket);
1198 temporary_error_free_resp:
1199 kfree(response);
1200 temporary_error:
1201 /* Ignore the response packet if we got a temporary error such as
1202 * ENOMEM. We just want to send the challenge again. Note that we
1203 * also come out this way if the ticket decryption fails.
1204 */
1205 return ret;
1206 }
1207
1208 /*
1209 * clear the connection security
1210 */
1211 static void rxkad_clear(struct rxrpc_connection *conn)
1212 {
1213 _enter("");
1214
1215 if (conn->cipher)
1216 crypto_free_skcipher(conn->cipher);
1217 }
1218
1219 /*
1220 * Initialise the rxkad security service.
1221 */
1222 static int rxkad_init(void)
1223 {
1224 /* pin the cipher we need so that the crypto layer doesn't invoke
1225 * keventd to go get it */
1226 rxkad_ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
1227 return PTR_ERR_OR_ZERO(rxkad_ci);
1228 }
1229
1230 /*
1231 * Clean up the rxkad security service.
1232 */
1233 static void rxkad_exit(void)
1234 {
1235 if (rxkad_ci)
1236 crypto_free_skcipher(rxkad_ci);
1237 }
1238
1239 /*
1240 * RxRPC Kerberos-based security
1241 */
1242 const struct rxrpc_security rxkad = {
1243 .name = "rxkad",
1244 .security_index = RXRPC_SECURITY_RXKAD,
1245 .init = rxkad_init,
1246 .exit = rxkad_exit,
1247 .init_connection_security = rxkad_init_connection_security,
1248 .prime_packet_security = rxkad_prime_packet_security,
1249 .secure_packet = rxkad_secure_packet,
1250 .verify_packet = rxkad_verify_packet,
1251 .locate_data = rxkad_locate_data,
1252 .issue_challenge = rxkad_issue_challenge,
1253 .respond_to_challenge = rxkad_respond_to_challenge,
1254 .verify_response = rxkad_verify_response,
1255 .clear = rxkad_clear,
1256 };
Linux with added FPC-III support