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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[mirror_ubuntu-jammy-kernel.git] / net / rxrpc / rxkad.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Kerberos-based RxRPC security
3 *
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10 #include <crypto/skcipher.h>
11 #include <linux/module.h>
12 #include <linux/net.h>
13 #include <linux/skbuff.h>
14 #include <linux/udp.h>
15 #include <linux/scatterlist.h>
16 #include <linux/ctype.h>
17 #include <linux/slab.h>
18 #include <linux/key-type.h>
19 #include <net/sock.h>
20 #include <net/af_rxrpc.h>
21 #include <keys/rxrpc-type.h>
22 #include "ar-internal.h"
23
24 #define RXKAD_VERSION 2
25 #define MAXKRB5TICKETLEN 1024
26 #define RXKAD_TKT_TYPE_KERBEROS_V5 256
27 #define ANAME_SZ 40 /* size of authentication name */
28 #define INST_SZ 40 /* size of principal's instance */
29 #define REALM_SZ 40 /* size of principal's auth domain */
30 #define SNAME_SZ 40 /* size of service name */
31 #define RXKAD_ALIGN 8
32
33 struct rxkad_level1_hdr {
34 __be32 data_size; /* true data size (excluding padding) */
35 };
36
37 struct rxkad_level2_hdr {
38 __be32 data_size; /* true data size (excluding padding) */
39 __be32 checksum; /* decrypted data checksum */
40 };
41
42 static int rxkad_prime_packet_security(struct rxrpc_connection *conn,
43 struct crypto_sync_skcipher *ci);
44
45 /*
46 * this holds a pinned cipher so that keventd doesn't get called by the cipher
47 * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
48 * packets
49 */
50 static struct crypto_sync_skcipher *rxkad_ci;
51 static struct skcipher_request *rxkad_ci_req;
52 static DEFINE_MUTEX(rxkad_ci_mutex);
53
54 /*
55 * Parse the information from a server key
56 *
57 * The data should be the 8-byte secret key.
58 */
59 static int rxkad_preparse_server_key(struct key_preparsed_payload *prep)
60 {
61 struct crypto_skcipher *ci;
62
63 if (prep->datalen != 8)
64 return -EINVAL;
65
66 memcpy(&prep->payload.data[2], prep->data, 8);
67
68 ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
69 if (IS_ERR(ci)) {
70 _leave(" = %ld", PTR_ERR(ci));
71 return PTR_ERR(ci);
72 }
73
74 if (crypto_skcipher_setkey(ci, prep->data, 8) < 0)
75 BUG();
76
77 prep->payload.data[0] = ci;
78 _leave(" = 0");
79 return 0;
80 }
81
82 static void rxkad_free_preparse_server_key(struct key_preparsed_payload *prep)
83 {
84
85 if (prep->payload.data[0])
86 crypto_free_skcipher(prep->payload.data[0]);
87 }
88
89 static void rxkad_destroy_server_key(struct key *key)
90 {
91 if (key->payload.data[0]) {
92 crypto_free_skcipher(key->payload.data[0]);
93 key->payload.data[0] = NULL;
94 }
95 }
96
97 /*
98 * initialise connection security
99 */
100 static int rxkad_init_connection_security(struct rxrpc_connection *conn,
101 struct rxrpc_key_token *token)
102 {
103 struct crypto_sync_skcipher *ci;
104 int ret;
105
106 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key));
107
108 conn->security_ix = token->security_index;
109
110 ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0);
111 if (IS_ERR(ci)) {
112 _debug("no cipher");
113 ret = PTR_ERR(ci);
114 goto error;
115 }
116
117 if (crypto_sync_skcipher_setkey(ci, token->kad->session_key,
118 sizeof(token->kad->session_key)) < 0)
119 BUG();
120
121 switch (conn->params.security_level) {
122 case RXRPC_SECURITY_PLAIN:
123 case RXRPC_SECURITY_AUTH:
124 case RXRPC_SECURITY_ENCRYPT:
125 break;
126 default:
127 ret = -EKEYREJECTED;
128 goto error;
129 }
130
131 ret = rxkad_prime_packet_security(conn, ci);
132 if (ret < 0)
133 goto error_ci;
134
135 conn->rxkad.cipher = ci;
136 return 0;
137
138 error_ci:
139 crypto_free_sync_skcipher(ci);
140 error:
141 _leave(" = %d", ret);
142 return ret;
143 }
144
145 /*
146 * Work out how much data we can put in a packet.
147 */
148 static int rxkad_how_much_data(struct rxrpc_call *call, size_t remain,
149 size_t *_buf_size, size_t *_data_size, size_t *_offset)
150 {
151 size_t shdr, buf_size, chunk;
152
153 switch (call->conn->params.security_level) {
154 default:
155 buf_size = chunk = min_t(size_t, remain, RXRPC_JUMBO_DATALEN);
156 shdr = 0;
157 goto out;
158 case RXRPC_SECURITY_AUTH:
159 shdr = sizeof(struct rxkad_level1_hdr);
160 break;
161 case RXRPC_SECURITY_ENCRYPT:
162 shdr = sizeof(struct rxkad_level2_hdr);
163 break;
164 }
165
166 buf_size = round_down(RXRPC_JUMBO_DATALEN, RXKAD_ALIGN);
167
168 chunk = buf_size - shdr;
169 if (remain < chunk)
170 buf_size = round_up(shdr + remain, RXKAD_ALIGN);
171
172 out:
173 *_buf_size = buf_size;
174 *_data_size = chunk;
175 *_offset = shdr;
176 return 0;
177 }
178
179 /*
180 * prime the encryption state with the invariant parts of a connection's
181 * description
182 */
183 static int rxkad_prime_packet_security(struct rxrpc_connection *conn,
184 struct crypto_sync_skcipher *ci)
185 {
186 struct skcipher_request *req;
187 struct rxrpc_key_token *token;
188 struct scatterlist sg;
189 struct rxrpc_crypt iv;
190 __be32 *tmpbuf;
191 size_t tmpsize = 4 * sizeof(__be32);
192
193 _enter("");
194
195 if (!conn->params.key)
196 return 0;
197
198 tmpbuf = kmalloc(tmpsize, GFP_KERNEL);
199 if (!tmpbuf)
200 return -ENOMEM;
201
202 req = skcipher_request_alloc(&ci->base, GFP_NOFS);
203 if (!req) {
204 kfree(tmpbuf);
205 return -ENOMEM;
206 }
207
208 token = conn->params.key->payload.data[0];
209 memcpy(&iv, token->kad->session_key, sizeof(iv));
210
211 tmpbuf[0] = htonl(conn->proto.epoch);
212 tmpbuf[1] = htonl(conn->proto.cid);
213 tmpbuf[2] = 0;
214 tmpbuf[3] = htonl(conn->security_ix);
215
216 sg_init_one(&sg, tmpbuf, tmpsize);
217 skcipher_request_set_sync_tfm(req, ci);
218 skcipher_request_set_callback(req, 0, NULL, NULL);
219 skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x);
220 crypto_skcipher_encrypt(req);
221 skcipher_request_free(req);
222
223 memcpy(&conn->rxkad.csum_iv, tmpbuf + 2, sizeof(conn->rxkad.csum_iv));
224 kfree(tmpbuf);
225 _leave(" = 0");
226 return 0;
227 }
228
229 /*
230 * Allocate and prepare the crypto request on a call. For any particular call,
231 * this is called serially for the packets, so no lock should be necessary.
232 */
233 static struct skcipher_request *rxkad_get_call_crypto(struct rxrpc_call *call)
234 {
235 struct crypto_skcipher *tfm = &call->conn->rxkad.cipher->base;
236 struct skcipher_request *cipher_req = call->cipher_req;
237
238 if (!cipher_req) {
239 cipher_req = skcipher_request_alloc(tfm, GFP_NOFS);
240 if (!cipher_req)
241 return NULL;
242 call->cipher_req = cipher_req;
243 }
244
245 return cipher_req;
246 }
247
248 /*
249 * Clean up the crypto on a call.
250 */
251 static void rxkad_free_call_crypto(struct rxrpc_call *call)
252 {
253 if (call->cipher_req)
254 skcipher_request_free(call->cipher_req);
255 call->cipher_req = NULL;
256 }
257
258 /*
259 * partially encrypt a packet (level 1 security)
260 */
261 static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
262 struct sk_buff *skb, u32 data_size,
263 struct skcipher_request *req)
264 {
265 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
266 struct rxkad_level1_hdr hdr;
267 struct rxrpc_crypt iv;
268 struct scatterlist sg;
269 size_t pad;
270 u16 check;
271
272 _enter("");
273
274 check = sp->hdr.seq ^ call->call_id;
275 data_size |= (u32)check << 16;
276
277 hdr.data_size = htonl(data_size);
278 memcpy(skb->head, &hdr, sizeof(hdr));
279
280 pad = sizeof(struct rxkad_level1_hdr) + data_size;
281 pad = RXKAD_ALIGN - pad;
282 pad &= RXKAD_ALIGN - 1;
283 if (pad)
284 skb_put_zero(skb, pad);
285
286 /* start the encryption afresh */
287 memset(&iv, 0, sizeof(iv));
288
289 sg_init_one(&sg, skb->head, 8);
290 skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
291 skcipher_request_set_callback(req, 0, NULL, NULL);
292 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
293 crypto_skcipher_encrypt(req);
294 skcipher_request_zero(req);
295
296 _leave(" = 0");
297 return 0;
298 }
299
300 /*
301 * wholly encrypt a packet (level 2 security)
302 */
303 static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
304 struct sk_buff *skb,
305 u32 data_size,
306 struct skcipher_request *req)
307 {
308 const struct rxrpc_key_token *token;
309 struct rxkad_level2_hdr rxkhdr;
310 struct rxrpc_skb_priv *sp;
311 struct rxrpc_crypt iv;
312 struct scatterlist sg[16];
313 unsigned int len;
314 size_t pad;
315 u16 check;
316 int err;
317
318 sp = rxrpc_skb(skb);
319
320 _enter("");
321
322 check = sp->hdr.seq ^ call->call_id;
323
324 rxkhdr.data_size = htonl(data_size | (u32)check << 16);
325 rxkhdr.checksum = 0;
326 memcpy(skb->head, &rxkhdr, sizeof(rxkhdr));
327
328 pad = sizeof(struct rxkad_level2_hdr) + data_size;
329 pad = RXKAD_ALIGN - pad;
330 pad &= RXKAD_ALIGN - 1;
331 if (pad)
332 skb_put_zero(skb, pad);
333
334 /* encrypt from the session key */
335 token = call->conn->params.key->payload.data[0];
336 memcpy(&iv, token->kad->session_key, sizeof(iv));
337
338 sg_init_one(&sg[0], skb->head, sizeof(rxkhdr));
339 skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
340 skcipher_request_set_callback(req, 0, NULL, NULL);
341 skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x);
342 crypto_skcipher_encrypt(req);
343
344 /* we want to encrypt the skbuff in-place */
345 err = -EMSGSIZE;
346 if (skb_shinfo(skb)->nr_frags > 16)
347 goto out;
348
349 len = round_up(data_size, RXKAD_ALIGN);
350
351 sg_init_table(sg, ARRAY_SIZE(sg));
352 err = skb_to_sgvec(skb, sg, 8, len);
353 if (unlikely(err < 0))
354 goto out;
355 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
356 crypto_skcipher_encrypt(req);
357
358 _leave(" = 0");
359 err = 0;
360
361 out:
362 skcipher_request_zero(req);
363 return err;
364 }
365
366 /*
367 * checksum an RxRPC packet header
368 */
369 static int rxkad_secure_packet(struct rxrpc_call *call,
370 struct sk_buff *skb,
371 size_t data_size)
372 {
373 struct rxrpc_skb_priv *sp;
374 struct skcipher_request *req;
375 struct rxrpc_crypt iv;
376 struct scatterlist sg;
377 u32 x, y;
378 int ret;
379
380 sp = rxrpc_skb(skb);
381
382 _enter("{%d{%x}},{#%u},%zu,",
383 call->debug_id, key_serial(call->conn->params.key),
384 sp->hdr.seq, data_size);
385
386 if (!call->conn->rxkad.cipher)
387 return 0;
388
389 ret = key_validate(call->conn->params.key);
390 if (ret < 0)
391 return ret;
392
393 req = rxkad_get_call_crypto(call);
394 if (!req)
395 return -ENOMEM;
396
397 /* continue encrypting from where we left off */
398 memcpy(&iv, call->conn->rxkad.csum_iv.x, sizeof(iv));
399
400 /* calculate the security checksum */
401 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
402 x |= sp->hdr.seq & 0x3fffffff;
403 call->crypto_buf[0] = htonl(call->call_id);
404 call->crypto_buf[1] = htonl(x);
405
406 sg_init_one(&sg, call->crypto_buf, 8);
407 skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
408 skcipher_request_set_callback(req, 0, NULL, NULL);
409 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
410 crypto_skcipher_encrypt(req);
411 skcipher_request_zero(req);
412
413 y = ntohl(call->crypto_buf[1]);
414 y = (y >> 16) & 0xffff;
415 if (y == 0)
416 y = 1; /* zero checksums are not permitted */
417 sp->hdr.cksum = y;
418
419 switch (call->conn->params.security_level) {
420 case RXRPC_SECURITY_PLAIN:
421 ret = 0;
422 break;
423 case RXRPC_SECURITY_AUTH:
424 ret = rxkad_secure_packet_auth(call, skb, data_size, req);
425 break;
426 case RXRPC_SECURITY_ENCRYPT:
427 ret = rxkad_secure_packet_encrypt(call, skb, data_size, req);
428 break;
429 default:
430 ret = -EPERM;
431 break;
432 }
433
434 _leave(" = %d [set %hx]", ret, y);
435 return ret;
436 }
437
438 /*
439 * decrypt partial encryption on a packet (level 1 security)
440 */
441 static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
442 unsigned int offset, unsigned int len,
443 rxrpc_seq_t seq,
444 struct skcipher_request *req)
445 {
446 struct rxkad_level1_hdr sechdr;
447 struct rxrpc_crypt iv;
448 struct scatterlist sg[16];
449 bool aborted;
450 u32 data_size, buf;
451 u16 check;
452 int ret;
453
454 _enter("");
455
456 if (len < 8) {
457 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H",
458 RXKADSEALEDINCON);
459 goto protocol_error;
460 }
461
462 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
463 * directly into the target buffer.
464 */
465 sg_init_table(sg, ARRAY_SIZE(sg));
466 ret = skb_to_sgvec(skb, sg, offset, 8);
467 if (unlikely(ret < 0))
468 return ret;
469
470 /* start the decryption afresh */
471 memset(&iv, 0, sizeof(iv));
472
473 skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
474 skcipher_request_set_callback(req, 0, NULL, NULL);
475 skcipher_request_set_crypt(req, sg, sg, 8, iv.x);
476 crypto_skcipher_decrypt(req);
477 skcipher_request_zero(req);
478
479 /* Extract the decrypted packet length */
480 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
481 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1",
482 RXKADDATALEN);
483 goto protocol_error;
484 }
485 offset += sizeof(sechdr);
486 len -= sizeof(sechdr);
487
488 buf = ntohl(sechdr.data_size);
489 data_size = buf & 0xffff;
490
491 check = buf >> 16;
492 check ^= seq ^ call->call_id;
493 check &= 0xffff;
494 if (check != 0) {
495 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C",
496 RXKADSEALEDINCON);
497 goto protocol_error;
498 }
499
500 if (data_size > len) {
501 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L",
502 RXKADDATALEN);
503 goto protocol_error;
504 }
505
506 _leave(" = 0 [dlen=%x]", data_size);
507 return 0;
508
509 protocol_error:
510 if (aborted)
511 rxrpc_send_abort_packet(call);
512 return -EPROTO;
513 }
514
515 /*
516 * wholly decrypt a packet (level 2 security)
517 */
518 static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
519 unsigned int offset, unsigned int len,
520 rxrpc_seq_t seq,
521 struct skcipher_request *req)
522 {
523 const struct rxrpc_key_token *token;
524 struct rxkad_level2_hdr sechdr;
525 struct rxrpc_crypt iv;
526 struct scatterlist _sg[4], *sg;
527 bool aborted;
528 u32 data_size, buf;
529 u16 check;
530 int nsg, ret;
531
532 _enter(",{%d}", skb->len);
533
534 if (len < 8) {
535 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H",
536 RXKADSEALEDINCON);
537 goto protocol_error;
538 }
539
540 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
541 * directly into the target buffer.
542 */
543 sg = _sg;
544 nsg = skb_shinfo(skb)->nr_frags;
545 if (nsg <= 4) {
546 nsg = 4;
547 } else {
548 sg = kmalloc_array(nsg, sizeof(*sg), GFP_NOIO);
549 if (!sg)
550 goto nomem;
551 }
552
553 sg_init_table(sg, nsg);
554 ret = skb_to_sgvec(skb, sg, offset, len);
555 if (unlikely(ret < 0)) {
556 if (sg != _sg)
557 kfree(sg);
558 return ret;
559 }
560
561 /* decrypt from the session key */
562 token = call->conn->params.key->payload.data[0];
563 memcpy(&iv, token->kad->session_key, sizeof(iv));
564
565 skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
566 skcipher_request_set_callback(req, 0, NULL, NULL);
567 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
568 crypto_skcipher_decrypt(req);
569 skcipher_request_zero(req);
570 if (sg != _sg)
571 kfree(sg);
572
573 /* Extract the decrypted packet length */
574 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
575 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2",
576 RXKADDATALEN);
577 goto protocol_error;
578 }
579 offset += sizeof(sechdr);
580 len -= sizeof(sechdr);
581
582 buf = ntohl(sechdr.data_size);
583 data_size = buf & 0xffff;
584
585 check = buf >> 16;
586 check ^= seq ^ call->call_id;
587 check &= 0xffff;
588 if (check != 0) {
589 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C",
590 RXKADSEALEDINCON);
591 goto protocol_error;
592 }
593
594 if (data_size > len) {
595 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L",
596 RXKADDATALEN);
597 goto protocol_error;
598 }
599
600 _leave(" = 0 [dlen=%x]", data_size);
601 return 0;
602
603 protocol_error:
604 if (aborted)
605 rxrpc_send_abort_packet(call);
606 return -EPROTO;
607
608 nomem:
609 _leave(" = -ENOMEM");
610 return -ENOMEM;
611 }
612
613 /*
614 * Verify the security on a received packet or subpacket (if part of a
615 * jumbo packet).
616 */
617 static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
618 unsigned int offset, unsigned int len,
619 rxrpc_seq_t seq, u16 expected_cksum)
620 {
621 struct skcipher_request *req;
622 struct rxrpc_crypt iv;
623 struct scatterlist sg;
624 bool aborted;
625 u16 cksum;
626 u32 x, y;
627
628 _enter("{%d{%x}},{#%u}",
629 call->debug_id, key_serial(call->conn->params.key), seq);
630
631 if (!call->conn->rxkad.cipher)
632 return 0;
633
634 req = rxkad_get_call_crypto(call);
635 if (!req)
636 return -ENOMEM;
637
638 /* continue encrypting from where we left off */
639 memcpy(&iv, call->conn->rxkad.csum_iv.x, sizeof(iv));
640
641 /* validate the security checksum */
642 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
643 x |= seq & 0x3fffffff;
644 call->crypto_buf[0] = htonl(call->call_id);
645 call->crypto_buf[1] = htonl(x);
646
647 sg_init_one(&sg, call->crypto_buf, 8);
648 skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
649 skcipher_request_set_callback(req, 0, NULL, NULL);
650 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
651 crypto_skcipher_encrypt(req);
652 skcipher_request_zero(req);
653
654 y = ntohl(call->crypto_buf[1]);
655 cksum = (y >> 16) & 0xffff;
656 if (cksum == 0)
657 cksum = 1; /* zero checksums are not permitted */
658
659 if (cksum != expected_cksum) {
660 aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK",
661 RXKADSEALEDINCON);
662 goto protocol_error;
663 }
664
665 switch (call->conn->params.security_level) {
666 case RXRPC_SECURITY_PLAIN:
667 return 0;
668 case RXRPC_SECURITY_AUTH:
669 return rxkad_verify_packet_1(call, skb, offset, len, seq, req);
670 case RXRPC_SECURITY_ENCRYPT:
671 return rxkad_verify_packet_2(call, skb, offset, len, seq, req);
672 default:
673 return -ENOANO;
674 }
675
676 protocol_error:
677 if (aborted)
678 rxrpc_send_abort_packet(call);
679 return -EPROTO;
680 }
681
682 /*
683 * Locate the data contained in a packet that was partially encrypted.
684 */
685 static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
686 unsigned int *_offset, unsigned int *_len)
687 {
688 struct rxkad_level1_hdr sechdr;
689
690 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
691 BUG();
692 *_offset += sizeof(sechdr);
693 *_len = ntohl(sechdr.data_size) & 0xffff;
694 }
695
696 /*
697 * Locate the data contained in a packet that was completely encrypted.
698 */
699 static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
700 unsigned int *_offset, unsigned int *_len)
701 {
702 struct rxkad_level2_hdr sechdr;
703
704 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
705 BUG();
706 *_offset += sizeof(sechdr);
707 *_len = ntohl(sechdr.data_size) & 0xffff;
708 }
709
710 /*
711 * Locate the data contained in an already decrypted packet.
712 */
713 static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
714 unsigned int *_offset, unsigned int *_len)
715 {
716 switch (call->conn->params.security_level) {
717 case RXRPC_SECURITY_AUTH:
718 rxkad_locate_data_1(call, skb, _offset, _len);
719 return;
720 case RXRPC_SECURITY_ENCRYPT:
721 rxkad_locate_data_2(call, skb, _offset, _len);
722 return;
723 default:
724 return;
725 }
726 }
727
728 /*
729 * issue a challenge
730 */
731 static int rxkad_issue_challenge(struct rxrpc_connection *conn)
732 {
733 struct rxkad_challenge challenge;
734 struct rxrpc_wire_header whdr;
735 struct msghdr msg;
736 struct kvec iov[2];
737 size_t len;
738 u32 serial;
739 int ret;
740
741 _enter("{%d}", conn->debug_id);
742
743 get_random_bytes(&conn->rxkad.nonce, sizeof(conn->rxkad.nonce));
744
745 challenge.version = htonl(2);
746 challenge.nonce = htonl(conn->rxkad.nonce);
747 challenge.min_level = htonl(0);
748 challenge.__padding = 0;
749
750 msg.msg_name = &conn->params.peer->srx.transport;
751 msg.msg_namelen = conn->params.peer->srx.transport_len;
752 msg.msg_control = NULL;
753 msg.msg_controllen = 0;
754 msg.msg_flags = 0;
755
756 whdr.epoch = htonl(conn->proto.epoch);
757 whdr.cid = htonl(conn->proto.cid);
758 whdr.callNumber = 0;
759 whdr.seq = 0;
760 whdr.type = RXRPC_PACKET_TYPE_CHALLENGE;
761 whdr.flags = conn->out_clientflag;
762 whdr.userStatus = 0;
763 whdr.securityIndex = conn->security_ix;
764 whdr._rsvd = 0;
765 whdr.serviceId = htons(conn->service_id);
766
767 iov[0].iov_base = &whdr;
768 iov[0].iov_len = sizeof(whdr);
769 iov[1].iov_base = &challenge;
770 iov[1].iov_len = sizeof(challenge);
771
772 len = iov[0].iov_len + iov[1].iov_len;
773
774 serial = atomic_inc_return(&conn->serial);
775 whdr.serial = htonl(serial);
776 _proto("Tx CHALLENGE %%%u", serial);
777
778 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
779 if (ret < 0) {
780 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
781 rxrpc_tx_point_rxkad_challenge);
782 return -EAGAIN;
783 }
784
785 conn->params.peer->last_tx_at = ktime_get_seconds();
786 trace_rxrpc_tx_packet(conn->debug_id, &whdr,
787 rxrpc_tx_point_rxkad_challenge);
788 _leave(" = 0");
789 return 0;
790 }
791
792 /*
793 * send a Kerberos security response
794 */
795 static int rxkad_send_response(struct rxrpc_connection *conn,
796 struct rxrpc_host_header *hdr,
797 struct rxkad_response *resp,
798 const struct rxkad_key *s2)
799 {
800 struct rxrpc_wire_header whdr;
801 struct msghdr msg;
802 struct kvec iov[3];
803 size_t len;
804 u32 serial;
805 int ret;
806
807 _enter("");
808
809 msg.msg_name = &conn->params.peer->srx.transport;
810 msg.msg_namelen = conn->params.peer->srx.transport_len;
811 msg.msg_control = NULL;
812 msg.msg_controllen = 0;
813 msg.msg_flags = 0;
814
815 memset(&whdr, 0, sizeof(whdr));
816 whdr.epoch = htonl(hdr->epoch);
817 whdr.cid = htonl(hdr->cid);
818 whdr.type = RXRPC_PACKET_TYPE_RESPONSE;
819 whdr.flags = conn->out_clientflag;
820 whdr.securityIndex = hdr->securityIndex;
821 whdr.serviceId = htons(hdr->serviceId);
822
823 iov[0].iov_base = &whdr;
824 iov[0].iov_len = sizeof(whdr);
825 iov[1].iov_base = resp;
826 iov[1].iov_len = sizeof(*resp);
827 iov[2].iov_base = (void *)s2->ticket;
828 iov[2].iov_len = s2->ticket_len;
829
830 len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
831
832 serial = atomic_inc_return(&conn->serial);
833 whdr.serial = htonl(serial);
834 _proto("Tx RESPONSE %%%u", serial);
835
836 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len);
837 if (ret < 0) {
838 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
839 rxrpc_tx_point_rxkad_response);
840 return -EAGAIN;
841 }
842
843 conn->params.peer->last_tx_at = ktime_get_seconds();
844 _leave(" = 0");
845 return 0;
846 }
847
848 /*
849 * calculate the response checksum
850 */
851 static void rxkad_calc_response_checksum(struct rxkad_response *response)
852 {
853 u32 csum = 1000003;
854 int loop;
855 u8 *p = (u8 *) response;
856
857 for (loop = sizeof(*response); loop > 0; loop--)
858 csum = csum * 0x10204081 + *p++;
859
860 response->encrypted.checksum = htonl(csum);
861 }
862
863 /*
864 * encrypt the response packet
865 */
866 static int rxkad_encrypt_response(struct rxrpc_connection *conn,
867 struct rxkad_response *resp,
868 const struct rxkad_key *s2)
869 {
870 struct skcipher_request *req;
871 struct rxrpc_crypt iv;
872 struct scatterlist sg[1];
873
874 req = skcipher_request_alloc(&conn->rxkad.cipher->base, GFP_NOFS);
875 if (!req)
876 return -ENOMEM;
877
878 /* continue encrypting from where we left off */
879 memcpy(&iv, s2->session_key, sizeof(iv));
880
881 sg_init_table(sg, 1);
882 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
883 skcipher_request_set_sync_tfm(req, conn->rxkad.cipher);
884 skcipher_request_set_callback(req, 0, NULL, NULL);
885 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
886 crypto_skcipher_encrypt(req);
887 skcipher_request_free(req);
888 return 0;
889 }
890
891 /*
892 * respond to a challenge packet
893 */
894 static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
895 struct sk_buff *skb,
896 u32 *_abort_code)
897 {
898 const struct rxrpc_key_token *token;
899 struct rxkad_challenge challenge;
900 struct rxkad_response *resp;
901 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
902 const char *eproto;
903 u32 version, nonce, min_level, abort_code;
904 int ret;
905
906 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
907
908 eproto = tracepoint_string("chall_no_key");
909 abort_code = RX_PROTOCOL_ERROR;
910 if (!conn->params.key)
911 goto protocol_error;
912
913 abort_code = RXKADEXPIRED;
914 ret = key_validate(conn->params.key);
915 if (ret < 0)
916 goto other_error;
917
918 eproto = tracepoint_string("chall_short");
919 abort_code = RXKADPACKETSHORT;
920 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
921 &challenge, sizeof(challenge)) < 0)
922 goto protocol_error;
923
924 version = ntohl(challenge.version);
925 nonce = ntohl(challenge.nonce);
926 min_level = ntohl(challenge.min_level);
927
928 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
929 sp->hdr.serial, version, nonce, min_level);
930
931 eproto = tracepoint_string("chall_ver");
932 abort_code = RXKADINCONSISTENCY;
933 if (version != RXKAD_VERSION)
934 goto protocol_error;
935
936 abort_code = RXKADLEVELFAIL;
937 ret = -EACCES;
938 if (conn->params.security_level < min_level)
939 goto other_error;
940
941 token = conn->params.key->payload.data[0];
942
943 /* build the response packet */
944 resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
945 if (!resp)
946 return -ENOMEM;
947
948 resp->version = htonl(RXKAD_VERSION);
949 resp->encrypted.epoch = htonl(conn->proto.epoch);
950 resp->encrypted.cid = htonl(conn->proto.cid);
951 resp->encrypted.securityIndex = htonl(conn->security_ix);
952 resp->encrypted.inc_nonce = htonl(nonce + 1);
953 resp->encrypted.level = htonl(conn->params.security_level);
954 resp->kvno = htonl(token->kad->kvno);
955 resp->ticket_len = htonl(token->kad->ticket_len);
956 resp->encrypted.call_id[0] = htonl(conn->channels[0].call_counter);
957 resp->encrypted.call_id[1] = htonl(conn->channels[1].call_counter);
958 resp->encrypted.call_id[2] = htonl(conn->channels[2].call_counter);
959 resp->encrypted.call_id[3] = htonl(conn->channels[3].call_counter);
960
961 /* calculate the response checksum and then do the encryption */
962 rxkad_calc_response_checksum(resp);
963 ret = rxkad_encrypt_response(conn, resp, token->kad);
964 if (ret == 0)
965 ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad);
966 kfree(resp);
967 return ret;
968
969 protocol_error:
970 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
971 ret = -EPROTO;
972 other_error:
973 *_abort_code = abort_code;
974 return ret;
975 }
976
977 /*
978 * decrypt the kerberos IV ticket in the response
979 */
980 static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
981 struct key *server_key,
982 struct sk_buff *skb,
983 void *ticket, size_t ticket_len,
984 struct rxrpc_crypt *_session_key,
985 time64_t *_expiry,
986 u32 *_abort_code)
987 {
988 struct skcipher_request *req;
989 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
990 struct rxrpc_crypt iv, key;
991 struct scatterlist sg[1];
992 struct in_addr addr;
993 unsigned int life;
994 const char *eproto;
995 time64_t issue, now;
996 bool little_endian;
997 int ret;
998 u32 abort_code;
999 u8 *p, *q, *name, *end;
1000
1001 _enter("{%d},{%x}", conn->debug_id, key_serial(server_key));
1002
1003 *_expiry = 0;
1004
1005 ASSERT(server_key->payload.data[0] != NULL);
1006 ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
1007
1008 memcpy(&iv, &server_key->payload.data[2], sizeof(iv));
1009
1010 ret = -ENOMEM;
1011 req = skcipher_request_alloc(server_key->payload.data[0], GFP_NOFS);
1012 if (!req)
1013 goto temporary_error;
1014
1015 sg_init_one(&sg[0], ticket, ticket_len);
1016 skcipher_request_set_callback(req, 0, NULL, NULL);
1017 skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x);
1018 crypto_skcipher_decrypt(req);
1019 skcipher_request_free(req);
1020
1021 p = ticket;
1022 end = p + ticket_len;
1023
1024 #define Z(field) \
1025 ({ \
1026 u8 *__str = p; \
1027 eproto = tracepoint_string("rxkad_bad_"#field); \
1028 q = memchr(p, 0, end - p); \
1029 if (!q || q - p > (field##_SZ)) \
1030 goto bad_ticket; \
1031 for (; p < q; p++) \
1032 if (!isprint(*p)) \
1033 goto bad_ticket; \
1034 p++; \
1035 __str; \
1036 })
1037
1038 /* extract the ticket flags */
1039 _debug("KIV FLAGS: %x", *p);
1040 little_endian = *p & 1;
1041 p++;
1042
1043 /* extract the authentication name */
1044 name = Z(ANAME);
1045 _debug("KIV ANAME: %s", name);
1046
1047 /* extract the principal's instance */
1048 name = Z(INST);
1049 _debug("KIV INST : %s", name);
1050
1051 /* extract the principal's authentication domain */
1052 name = Z(REALM);
1053 _debug("KIV REALM: %s", name);
1054
1055 eproto = tracepoint_string("rxkad_bad_len");
1056 if (end - p < 4 + 8 + 4 + 2)
1057 goto bad_ticket;
1058
1059 /* get the IPv4 address of the entity that requested the ticket */
1060 memcpy(&addr, p, sizeof(addr));
1061 p += 4;
1062 _debug("KIV ADDR : %pI4", &addr);
1063
1064 /* get the session key from the ticket */
1065 memcpy(&key, p, sizeof(key));
1066 p += 8;
1067 _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
1068 memcpy(_session_key, &key, sizeof(key));
1069
1070 /* get the ticket's lifetime */
1071 life = *p++ * 5 * 60;
1072 _debug("KIV LIFE : %u", life);
1073
1074 /* get the issue time of the ticket */
1075 if (little_endian) {
1076 __le32 stamp;
1077 memcpy(&stamp, p, 4);
1078 issue = rxrpc_u32_to_time64(le32_to_cpu(stamp));
1079 } else {
1080 __be32 stamp;
1081 memcpy(&stamp, p, 4);
1082 issue = rxrpc_u32_to_time64(be32_to_cpu(stamp));
1083 }
1084 p += 4;
1085 now = ktime_get_real_seconds();
1086 _debug("KIV ISSUE: %llx [%llx]", issue, now);
1087
1088 /* check the ticket is in date */
1089 if (issue > now) {
1090 abort_code = RXKADNOAUTH;
1091 ret = -EKEYREJECTED;
1092 goto other_error;
1093 }
1094
1095 if (issue < now - life) {
1096 abort_code = RXKADEXPIRED;
1097 ret = -EKEYEXPIRED;
1098 goto other_error;
1099 }
1100
1101 *_expiry = issue + life;
1102
1103 /* get the service name */
1104 name = Z(SNAME);
1105 _debug("KIV SNAME: %s", name);
1106
1107 /* get the service instance name */
1108 name = Z(INST);
1109 _debug("KIV SINST: %s", name);
1110 return 0;
1111
1112 bad_ticket:
1113 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1114 abort_code = RXKADBADTICKET;
1115 ret = -EPROTO;
1116 other_error:
1117 *_abort_code = abort_code;
1118 return ret;
1119 temporary_error:
1120 return ret;
1121 }
1122
1123 /*
1124 * decrypt the response packet
1125 */
1126 static void rxkad_decrypt_response(struct rxrpc_connection *conn,
1127 struct rxkad_response *resp,
1128 const struct rxrpc_crypt *session_key)
1129 {
1130 struct skcipher_request *req = rxkad_ci_req;
1131 struct scatterlist sg[1];
1132 struct rxrpc_crypt iv;
1133
1134 _enter(",,%08x%08x",
1135 ntohl(session_key->n[0]), ntohl(session_key->n[1]));
1136
1137 mutex_lock(&rxkad_ci_mutex);
1138 if (crypto_sync_skcipher_setkey(rxkad_ci, session_key->x,
1139 sizeof(*session_key)) < 0)
1140 BUG();
1141
1142 memcpy(&iv, session_key, sizeof(iv));
1143
1144 sg_init_table(sg, 1);
1145 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
1146 skcipher_request_set_sync_tfm(req, rxkad_ci);
1147 skcipher_request_set_callback(req, 0, NULL, NULL);
1148 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
1149 crypto_skcipher_decrypt(req);
1150 skcipher_request_zero(req);
1151
1152 mutex_unlock(&rxkad_ci_mutex);
1153
1154 _leave("");
1155 }
1156
1157 /*
1158 * verify a response
1159 */
1160 static int rxkad_verify_response(struct rxrpc_connection *conn,
1161 struct sk_buff *skb,
1162 u32 *_abort_code)
1163 {
1164 struct rxkad_response *response;
1165 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1166 struct rxrpc_crypt session_key;
1167 struct key *server_key;
1168 const char *eproto;
1169 time64_t expiry;
1170 void *ticket;
1171 u32 abort_code, version, kvno, ticket_len, level;
1172 __be32 csum;
1173 int ret, i;
1174
1175 _enter("{%d}", conn->debug_id);
1176
1177 server_key = rxrpc_look_up_server_security(conn, skb, 0, 0);
1178 if (IS_ERR(server_key)) {
1179 switch (PTR_ERR(server_key)) {
1180 case -ENOKEY:
1181 abort_code = RXKADUNKNOWNKEY;
1182 break;
1183 case -EKEYEXPIRED:
1184 abort_code = RXKADEXPIRED;
1185 break;
1186 default:
1187 abort_code = RXKADNOAUTH;
1188 break;
1189 }
1190 trace_rxrpc_abort(0, "SVK",
1191 sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1192 abort_code, PTR_ERR(server_key));
1193 *_abort_code = abort_code;
1194 return -EPROTO;
1195 }
1196
1197 ret = -ENOMEM;
1198 response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
1199 if (!response)
1200 goto temporary_error;
1201
1202 eproto = tracepoint_string("rxkad_rsp_short");
1203 abort_code = RXKADPACKETSHORT;
1204 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1205 response, sizeof(*response)) < 0)
1206 goto protocol_error;
1207
1208 version = ntohl(response->version);
1209 ticket_len = ntohl(response->ticket_len);
1210 kvno = ntohl(response->kvno);
1211 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1212 sp->hdr.serial, version, kvno, ticket_len);
1213
1214 eproto = tracepoint_string("rxkad_rsp_ver");
1215 abort_code = RXKADINCONSISTENCY;
1216 if (version != RXKAD_VERSION)
1217 goto protocol_error;
1218
1219 eproto = tracepoint_string("rxkad_rsp_tktlen");
1220 abort_code = RXKADTICKETLEN;
1221 if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
1222 goto protocol_error;
1223
1224 eproto = tracepoint_string("rxkad_rsp_unkkey");
1225 abort_code = RXKADUNKNOWNKEY;
1226 if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
1227 goto protocol_error;
1228
1229 /* extract the kerberos ticket and decrypt and decode it */
1230 ret = -ENOMEM;
1231 ticket = kmalloc(ticket_len, GFP_NOFS);
1232 if (!ticket)
1233 goto temporary_error_free_resp;
1234
1235 eproto = tracepoint_string("rxkad_tkt_short");
1236 abort_code = RXKADPACKETSHORT;
1237 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header) + sizeof(*response),
1238 ticket, ticket_len) < 0)
1239 goto protocol_error_free;
1240
1241 ret = rxkad_decrypt_ticket(conn, server_key, skb, ticket, ticket_len,
1242 &session_key, &expiry, _abort_code);
1243 if (ret < 0)
1244 goto temporary_error_free_ticket;
1245
1246 /* use the session key from inside the ticket to decrypt the
1247 * response */
1248 rxkad_decrypt_response(conn, response, &session_key);
1249
1250 eproto = tracepoint_string("rxkad_rsp_param");
1251 abort_code = RXKADSEALEDINCON;
1252 if (ntohl(response->encrypted.epoch) != conn->proto.epoch)
1253 goto protocol_error_free;
1254 if (ntohl(response->encrypted.cid) != conn->proto.cid)
1255 goto protocol_error_free;
1256 if (ntohl(response->encrypted.securityIndex) != conn->security_ix)
1257 goto protocol_error_free;
1258 csum = response->encrypted.checksum;
1259 response->encrypted.checksum = 0;
1260 rxkad_calc_response_checksum(response);
1261 eproto = tracepoint_string("rxkad_rsp_csum");
1262 if (response->encrypted.checksum != csum)
1263 goto protocol_error_free;
1264
1265 spin_lock(&conn->bundle->channel_lock);
1266 for (i = 0; i < RXRPC_MAXCALLS; i++) {
1267 struct rxrpc_call *call;
1268 u32 call_id = ntohl(response->encrypted.call_id[i]);
1269
1270 eproto = tracepoint_string("rxkad_rsp_callid");
1271 if (call_id > INT_MAX)
1272 goto protocol_error_unlock;
1273
1274 eproto = tracepoint_string("rxkad_rsp_callctr");
1275 if (call_id < conn->channels[i].call_counter)
1276 goto protocol_error_unlock;
1277
1278 eproto = tracepoint_string("rxkad_rsp_callst");
1279 if (call_id > conn->channels[i].call_counter) {
1280 call = rcu_dereference_protected(
1281 conn->channels[i].call,
1282 lockdep_is_held(&conn->bundle->channel_lock));
1283 if (call && call->state < RXRPC_CALL_COMPLETE)
1284 goto protocol_error_unlock;
1285 conn->channels[i].call_counter = call_id;
1286 }
1287 }
1288 spin_unlock(&conn->bundle->channel_lock);
1289
1290 eproto = tracepoint_string("rxkad_rsp_seq");
1291 abort_code = RXKADOUTOFSEQUENCE;
1292 if (ntohl(response->encrypted.inc_nonce) != conn->rxkad.nonce + 1)
1293 goto protocol_error_free;
1294
1295 eproto = tracepoint_string("rxkad_rsp_level");
1296 abort_code = RXKADLEVELFAIL;
1297 level = ntohl(response->encrypted.level);
1298 if (level > RXRPC_SECURITY_ENCRYPT)
1299 goto protocol_error_free;
1300 conn->params.security_level = level;
1301
1302 /* create a key to hold the security data and expiration time - after
1303 * this the connection security can be handled in exactly the same way
1304 * as for a client connection */
1305 ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
1306 if (ret < 0)
1307 goto temporary_error_free_ticket;
1308
1309 kfree(ticket);
1310 kfree(response);
1311 _leave(" = 0");
1312 return 0;
1313
1314 protocol_error_unlock:
1315 spin_unlock(&conn->bundle->channel_lock);
1316 protocol_error_free:
1317 kfree(ticket);
1318 protocol_error:
1319 kfree(response);
1320 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1321 key_put(server_key);
1322 *_abort_code = abort_code;
1323 return -EPROTO;
1324
1325 temporary_error_free_ticket:
1326 kfree(ticket);
1327 temporary_error_free_resp:
1328 kfree(response);
1329 temporary_error:
1330 /* Ignore the response packet if we got a temporary error such as
1331 * ENOMEM. We just want to send the challenge again. Note that we
1332 * also come out this way if the ticket decryption fails.
1333 */
1334 key_put(server_key);
1335 return ret;
1336 }
1337
1338 /*
1339 * clear the connection security
1340 */
1341 static void rxkad_clear(struct rxrpc_connection *conn)
1342 {
1343 _enter("");
1344
1345 if (conn->rxkad.cipher)
1346 crypto_free_sync_skcipher(conn->rxkad.cipher);
1347 }
1348
1349 /*
1350 * Initialise the rxkad security service.
1351 */
1352 static int rxkad_init(void)
1353 {
1354 struct crypto_sync_skcipher *tfm;
1355 struct skcipher_request *req;
1356
1357 /* pin the cipher we need so that the crypto layer doesn't invoke
1358 * keventd to go get it */
1359 tfm = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0);
1360 if (IS_ERR(tfm))
1361 return PTR_ERR(tfm);
1362
1363 req = skcipher_request_alloc(&tfm->base, GFP_KERNEL);
1364 if (!req)
1365 goto nomem_tfm;
1366
1367 rxkad_ci_req = req;
1368 rxkad_ci = tfm;
1369 return 0;
1370
1371 nomem_tfm:
1372 crypto_free_sync_skcipher(tfm);
1373 return -ENOMEM;
1374 }
1375
1376 /*
1377 * Clean up the rxkad security service.
1378 */
1379 static void rxkad_exit(void)
1380 {
1381 crypto_free_sync_skcipher(rxkad_ci);
1382 skcipher_request_free(rxkad_ci_req);
1383 }
1384
1385 /*
1386 * RxRPC Kerberos-based security
1387 */
1388 const struct rxrpc_security rxkad = {
1389 .name = "rxkad",
1390 .security_index = RXRPC_SECURITY_RXKAD,
1391 .no_key_abort = RXKADUNKNOWNKEY,
1392 .init = rxkad_init,
1393 .exit = rxkad_exit,
1394 .preparse_server_key = rxkad_preparse_server_key,
1395 .free_preparse_server_key = rxkad_free_preparse_server_key,
1396 .destroy_server_key = rxkad_destroy_server_key,
1397 .init_connection_security = rxkad_init_connection_security,
1398 .how_much_data = rxkad_how_much_data,
1399 .secure_packet = rxkad_secure_packet,
1400 .verify_packet = rxkad_verify_packet,
1401 .free_call_crypto = rxkad_free_call_crypto,
1402 .locate_data = rxkad_locate_data,
1403 .issue_challenge = rxkad_issue_challenge,
1404 .respond_to_challenge = rxkad_respond_to_challenge,
1405 .verify_response = rxkad_verify_response,
1406 .clear = rxkad_clear,
1407 };
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