Commit | Line | Data |
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17926a79 DH |
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 | #include <linux/module.h> | |
13 | #include <linux/net.h> | |
14 | #include <linux/skbuff.h> | |
15 | #include <linux/udp.h> | |
16 | #include <linux/crypto.h> | |
17 | #include <linux/scatterlist.h> | |
18 | #include <linux/ctype.h> | |
5a0e3ad6 | 19 | #include <linux/slab.h> |
17926a79 DH |
20 | #include <net/sock.h> |
21 | #include <net/af_rxrpc.h> | |
33941284 | 22 | #include <keys/rxrpc-type.h> |
b1bdb691 | 23 | #define rxrpc_debug rxkad_debug |
17926a79 DH |
24 | #include "ar-internal.h" |
25 | ||
26 | #define RXKAD_VERSION 2 | |
27 | #define MAXKRB5TICKETLEN 1024 | |
28 | #define RXKAD_TKT_TYPE_KERBEROS_V5 256 | |
29 | #define ANAME_SZ 40 /* size of authentication name */ | |
30 | #define INST_SZ 40 /* size of principal's instance */ | |
31 | #define REALM_SZ 40 /* size of principal's auth domain */ | |
32 | #define SNAME_SZ 40 /* size of service name */ | |
33 | ||
95c96174 | 34 | unsigned int rxrpc_debug; |
17926a79 | 35 | module_param_named(debug, rxrpc_debug, uint, S_IWUSR | S_IRUGO); |
424b00e2 | 36 | MODULE_PARM_DESC(debug, "rxkad debugging mask"); |
17926a79 DH |
37 | |
38 | struct rxkad_level1_hdr { | |
39 | __be32 data_size; /* true data size (excluding padding) */ | |
40 | }; | |
41 | ||
42 | struct rxkad_level2_hdr { | |
43 | __be32 data_size; /* true data size (excluding padding) */ | |
44 | __be32 checksum; /* decrypted data checksum */ | |
45 | }; | |
46 | ||
8b815477 | 47 | MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos 4)"); |
17926a79 DH |
48 | MODULE_AUTHOR("Red Hat, Inc."); |
49 | MODULE_LICENSE("GPL"); | |
50 | ||
51 | /* | |
52 | * this holds a pinned cipher so that keventd doesn't get called by the cipher | |
53 | * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE | |
54 | * packets | |
55 | */ | |
56 | static struct crypto_blkcipher *rxkad_ci; | |
57 | static DEFINE_MUTEX(rxkad_ci_mutex); | |
58 | ||
59 | /* | |
60 | * initialise connection security | |
61 | */ | |
62 | static int rxkad_init_connection_security(struct rxrpc_connection *conn) | |
63 | { | |
17926a79 | 64 | struct crypto_blkcipher *ci; |
33941284 | 65 | struct rxrpc_key_token *token; |
17926a79 DH |
66 | int ret; |
67 | ||
68 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->key)); | |
69 | ||
146aa8b1 | 70 | token = conn->key->payload.data[0]; |
33941284 | 71 | conn->security_ix = token->security_index; |
17926a79 DH |
72 | |
73 | ci = crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC); | |
74 | if (IS_ERR(ci)) { | |
75 | _debug("no cipher"); | |
76 | ret = PTR_ERR(ci); | |
77 | goto error; | |
78 | } | |
79 | ||
33941284 DH |
80 | if (crypto_blkcipher_setkey(ci, token->kad->session_key, |
81 | sizeof(token->kad->session_key)) < 0) | |
17926a79 DH |
82 | BUG(); |
83 | ||
84 | switch (conn->security_level) { | |
85 | case RXRPC_SECURITY_PLAIN: | |
86 | break; | |
87 | case RXRPC_SECURITY_AUTH: | |
88 | conn->size_align = 8; | |
89 | conn->security_size = sizeof(struct rxkad_level1_hdr); | |
90 | conn->header_size += sizeof(struct rxkad_level1_hdr); | |
91 | break; | |
92 | case RXRPC_SECURITY_ENCRYPT: | |
93 | conn->size_align = 8; | |
94 | conn->security_size = sizeof(struct rxkad_level2_hdr); | |
95 | conn->header_size += sizeof(struct rxkad_level2_hdr); | |
96 | break; | |
97 | default: | |
98 | ret = -EKEYREJECTED; | |
99 | goto error; | |
100 | } | |
101 | ||
102 | conn->cipher = ci; | |
103 | ret = 0; | |
104 | error: | |
105 | _leave(" = %d", ret); | |
106 | return ret; | |
107 | } | |
108 | ||
109 | /* | |
110 | * prime the encryption state with the invariant parts of a connection's | |
111 | * description | |
112 | */ | |
113 | static void rxkad_prime_packet_security(struct rxrpc_connection *conn) | |
114 | { | |
33941284 | 115 | struct rxrpc_key_token *token; |
17926a79 DH |
116 | struct blkcipher_desc desc; |
117 | struct scatterlist sg[2]; | |
118 | struct rxrpc_crypt iv; | |
119 | struct { | |
120 | __be32 x[4]; | |
121 | } tmpbuf __attribute__((aligned(16))); /* must all be in same page */ | |
122 | ||
123 | _enter(""); | |
124 | ||
125 | if (!conn->key) | |
126 | return; | |
127 | ||
146aa8b1 | 128 | token = conn->key->payload.data[0]; |
33941284 | 129 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 DH |
130 | |
131 | desc.tfm = conn->cipher; | |
132 | desc.info = iv.x; | |
133 | desc.flags = 0; | |
134 | ||
0d12f8a4 DH |
135 | tmpbuf.x[0] = htonl(conn->epoch); |
136 | tmpbuf.x[1] = htonl(conn->cid); | |
17926a79 DH |
137 | tmpbuf.x[2] = 0; |
138 | tmpbuf.x[3] = htonl(conn->security_ix); | |
139 | ||
68e3f5dd HX |
140 | sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf)); |
141 | sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf)); | |
17926a79 DH |
142 | crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf)); |
143 | ||
144 | memcpy(&conn->csum_iv, &tmpbuf.x[2], sizeof(conn->csum_iv)); | |
145 | ASSERTCMP(conn->csum_iv.n[0], ==, tmpbuf.x[2]); | |
146 | ||
147 | _leave(""); | |
148 | } | |
149 | ||
150 | /* | |
151 | * partially encrypt a packet (level 1 security) | |
152 | */ | |
153 | static int rxkad_secure_packet_auth(const struct rxrpc_call *call, | |
154 | struct sk_buff *skb, | |
155 | u32 data_size, | |
156 | void *sechdr) | |
157 | { | |
158 | struct rxrpc_skb_priv *sp; | |
159 | struct blkcipher_desc desc; | |
160 | struct rxrpc_crypt iv; | |
161 | struct scatterlist sg[2]; | |
162 | struct { | |
163 | struct rxkad_level1_hdr hdr; | |
164 | __be32 first; /* first four bytes of data and padding */ | |
165 | } tmpbuf __attribute__((aligned(8))); /* must all be in same page */ | |
166 | u16 check; | |
167 | ||
168 | sp = rxrpc_skb(skb); | |
169 | ||
170 | _enter(""); | |
171 | ||
0d12f8a4 DH |
172 | check = sp->hdr.seq ^ sp->hdr.callNumber; |
173 | data_size |= (u32)check << 16; | |
17926a79 DH |
174 | |
175 | tmpbuf.hdr.data_size = htonl(data_size); | |
176 | memcpy(&tmpbuf.first, sechdr + 4, sizeof(tmpbuf.first)); | |
177 | ||
178 | /* start the encryption afresh */ | |
179 | memset(&iv, 0, sizeof(iv)); | |
180 | desc.tfm = call->conn->cipher; | |
181 | desc.info = iv.x; | |
182 | desc.flags = 0; | |
183 | ||
68e3f5dd HX |
184 | sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf)); |
185 | sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf)); | |
17926a79 DH |
186 | crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf)); |
187 | ||
188 | memcpy(sechdr, &tmpbuf, sizeof(tmpbuf)); | |
189 | ||
190 | _leave(" = 0"); | |
191 | return 0; | |
192 | } | |
193 | ||
194 | /* | |
195 | * wholly encrypt a packet (level 2 security) | |
196 | */ | |
197 | static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call, | |
b4f1342f DH |
198 | struct sk_buff *skb, |
199 | u32 data_size, | |
200 | void *sechdr) | |
17926a79 | 201 | { |
33941284 | 202 | const struct rxrpc_key_token *token; |
17926a79 DH |
203 | struct rxkad_level2_hdr rxkhdr |
204 | __attribute__((aligned(8))); /* must be all on one page */ | |
205 | struct rxrpc_skb_priv *sp; | |
206 | struct blkcipher_desc desc; | |
207 | struct rxrpc_crypt iv; | |
208 | struct scatterlist sg[16]; | |
209 | struct sk_buff *trailer; | |
95c96174 | 210 | unsigned int len; |
17926a79 DH |
211 | u16 check; |
212 | int nsg; | |
213 | ||
214 | sp = rxrpc_skb(skb); | |
215 | ||
216 | _enter(""); | |
217 | ||
0d12f8a4 | 218 | check = sp->hdr.seq ^ sp->hdr.callNumber; |
17926a79 | 219 | |
0d12f8a4 | 220 | rxkhdr.data_size = htonl(data_size | (u32)check << 16); |
17926a79 DH |
221 | rxkhdr.checksum = 0; |
222 | ||
223 | /* encrypt from the session key */ | |
146aa8b1 | 224 | token = call->conn->key->payload.data[0]; |
33941284 | 225 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 DH |
226 | desc.tfm = call->conn->cipher; |
227 | desc.info = iv.x; | |
228 | desc.flags = 0; | |
229 | ||
68e3f5dd HX |
230 | sg_init_one(&sg[0], sechdr, sizeof(rxkhdr)); |
231 | sg_init_one(&sg[1], &rxkhdr, sizeof(rxkhdr)); | |
17926a79 DH |
232 | crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(rxkhdr)); |
233 | ||
234 | /* we want to encrypt the skbuff in-place */ | |
235 | nsg = skb_cow_data(skb, 0, &trailer); | |
236 | if (nsg < 0 || nsg > 16) | |
237 | return -ENOMEM; | |
238 | ||
239 | len = data_size + call->conn->size_align - 1; | |
240 | len &= ~(call->conn->size_align - 1); | |
241 | ||
51c739d1 DM |
242 | sg_init_table(sg, nsg); |
243 | skb_to_sgvec(skb, sg, 0, len); | |
17926a79 DH |
244 | crypto_blkcipher_encrypt_iv(&desc, sg, sg, len); |
245 | ||
246 | _leave(" = 0"); | |
247 | return 0; | |
248 | } | |
249 | ||
250 | /* | |
251 | * checksum an RxRPC packet header | |
252 | */ | |
253 | static int rxkad_secure_packet(const struct rxrpc_call *call, | |
b4f1342f DH |
254 | struct sk_buff *skb, |
255 | size_t data_size, | |
256 | void *sechdr) | |
17926a79 DH |
257 | { |
258 | struct rxrpc_skb_priv *sp; | |
259 | struct blkcipher_desc desc; | |
260 | struct rxrpc_crypt iv; | |
261 | struct scatterlist sg[2]; | |
262 | struct { | |
263 | __be32 x[2]; | |
264 | } tmpbuf __attribute__((aligned(8))); /* must all be in same page */ | |
0d12f8a4 | 265 | u32 x, y; |
17926a79 DH |
266 | int ret; |
267 | ||
268 | sp = rxrpc_skb(skb); | |
269 | ||
270 | _enter("{%d{%x}},{#%u},%zu,", | |
0d12f8a4 | 271 | call->debug_id, key_serial(call->conn->key), sp->hdr.seq, |
17926a79 DH |
272 | data_size); |
273 | ||
274 | if (!call->conn->cipher) | |
275 | return 0; | |
276 | ||
277 | ret = key_validate(call->conn->key); | |
278 | if (ret < 0) | |
279 | return ret; | |
280 | ||
281 | /* continue encrypting from where we left off */ | |
282 | memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); | |
283 | desc.tfm = call->conn->cipher; | |
284 | desc.info = iv.x; | |
285 | desc.flags = 0; | |
286 | ||
287 | /* calculate the security checksum */ | |
0d12f8a4 DH |
288 | x = call->channel << (32 - RXRPC_CIDSHIFT); |
289 | x |= sp->hdr.seq & 0x3fffffff; | |
290 | tmpbuf.x[0] = htonl(sp->hdr.callNumber); | |
291 | tmpbuf.x[1] = htonl(x); | |
17926a79 | 292 | |
68e3f5dd HX |
293 | sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf)); |
294 | sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf)); | |
17926a79 DH |
295 | crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf)); |
296 | ||
91e916cf AV |
297 | y = ntohl(tmpbuf.x[1]); |
298 | y = (y >> 16) & 0xffff; | |
299 | if (y == 0) | |
300 | y = 1; /* zero checksums are not permitted */ | |
0d12f8a4 | 301 | sp->hdr.cksum = y; |
17926a79 DH |
302 | |
303 | switch (call->conn->security_level) { | |
304 | case RXRPC_SECURITY_PLAIN: | |
305 | ret = 0; | |
306 | break; | |
307 | case RXRPC_SECURITY_AUTH: | |
308 | ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr); | |
309 | break; | |
310 | case RXRPC_SECURITY_ENCRYPT: | |
311 | ret = rxkad_secure_packet_encrypt(call, skb, data_size, | |
312 | sechdr); | |
313 | break; | |
314 | default: | |
315 | ret = -EPERM; | |
316 | break; | |
317 | } | |
318 | ||
91e916cf | 319 | _leave(" = %d [set %hx]", ret, y); |
17926a79 DH |
320 | return ret; |
321 | } | |
322 | ||
323 | /* | |
324 | * decrypt partial encryption on a packet (level 1 security) | |
325 | */ | |
326 | static int rxkad_verify_packet_auth(const struct rxrpc_call *call, | |
327 | struct sk_buff *skb, | |
328 | u32 *_abort_code) | |
329 | { | |
330 | struct rxkad_level1_hdr sechdr; | |
331 | struct rxrpc_skb_priv *sp; | |
332 | struct blkcipher_desc desc; | |
333 | struct rxrpc_crypt iv; | |
68e3f5dd | 334 | struct scatterlist sg[16]; |
17926a79 DH |
335 | struct sk_buff *trailer; |
336 | u32 data_size, buf; | |
337 | u16 check; | |
68e3f5dd | 338 | int nsg; |
17926a79 DH |
339 | |
340 | _enter(""); | |
341 | ||
342 | sp = rxrpc_skb(skb); | |
343 | ||
344 | /* we want to decrypt the skbuff in-place */ | |
68e3f5dd HX |
345 | nsg = skb_cow_data(skb, 0, &trailer); |
346 | if (nsg < 0 || nsg > 16) | |
17926a79 DH |
347 | goto nomem; |
348 | ||
68e3f5dd | 349 | sg_init_table(sg, nsg); |
51c739d1 | 350 | skb_to_sgvec(skb, sg, 0, 8); |
17926a79 DH |
351 | |
352 | /* start the decryption afresh */ | |
353 | memset(&iv, 0, sizeof(iv)); | |
354 | desc.tfm = call->conn->cipher; | |
355 | desc.info = iv.x; | |
356 | desc.flags = 0; | |
357 | ||
358 | crypto_blkcipher_decrypt_iv(&desc, sg, sg, 8); | |
359 | ||
360 | /* remove the decrypted packet length */ | |
361 | if (skb_copy_bits(skb, 0, &sechdr, sizeof(sechdr)) < 0) | |
362 | goto datalen_error; | |
363 | if (!skb_pull(skb, sizeof(sechdr))) | |
364 | BUG(); | |
365 | ||
366 | buf = ntohl(sechdr.data_size); | |
367 | data_size = buf & 0xffff; | |
368 | ||
369 | check = buf >> 16; | |
0d12f8a4 | 370 | check ^= sp->hdr.seq ^ sp->hdr.callNumber; |
17926a79 DH |
371 | check &= 0xffff; |
372 | if (check != 0) { | |
373 | *_abort_code = RXKADSEALEDINCON; | |
374 | goto protocol_error; | |
375 | } | |
376 | ||
377 | /* shorten the packet to remove the padding */ | |
378 | if (data_size > skb->len) | |
379 | goto datalen_error; | |
380 | else if (data_size < skb->len) | |
381 | skb->len = data_size; | |
382 | ||
383 | _leave(" = 0 [dlen=%x]", data_size); | |
384 | return 0; | |
385 | ||
386 | datalen_error: | |
387 | *_abort_code = RXKADDATALEN; | |
388 | protocol_error: | |
389 | _leave(" = -EPROTO"); | |
390 | return -EPROTO; | |
391 | ||
392 | nomem: | |
393 | _leave(" = -ENOMEM"); | |
394 | return -ENOMEM; | |
395 | } | |
396 | ||
397 | /* | |
398 | * wholly decrypt a packet (level 2 security) | |
399 | */ | |
400 | static int rxkad_verify_packet_encrypt(const struct rxrpc_call *call, | |
401 | struct sk_buff *skb, | |
402 | u32 *_abort_code) | |
403 | { | |
33941284 | 404 | const struct rxrpc_key_token *token; |
17926a79 DH |
405 | struct rxkad_level2_hdr sechdr; |
406 | struct rxrpc_skb_priv *sp; | |
407 | struct blkcipher_desc desc; | |
408 | struct rxrpc_crypt iv; | |
409 | struct scatterlist _sg[4], *sg; | |
410 | struct sk_buff *trailer; | |
411 | u32 data_size, buf; | |
412 | u16 check; | |
413 | int nsg; | |
414 | ||
415 | _enter(",{%d}", skb->len); | |
416 | ||
417 | sp = rxrpc_skb(skb); | |
418 | ||
419 | /* we want to decrypt the skbuff in-place */ | |
420 | nsg = skb_cow_data(skb, 0, &trailer); | |
421 | if (nsg < 0) | |
422 | goto nomem; | |
423 | ||
424 | sg = _sg; | |
425 | if (unlikely(nsg > 4)) { | |
426 | sg = kmalloc(sizeof(*sg) * nsg, GFP_NOIO); | |
427 | if (!sg) | |
428 | goto nomem; | |
429 | } | |
430 | ||
68e3f5dd | 431 | sg_init_table(sg, nsg); |
51c739d1 | 432 | skb_to_sgvec(skb, sg, 0, skb->len); |
17926a79 DH |
433 | |
434 | /* decrypt from the session key */ | |
146aa8b1 | 435 | token = call->conn->key->payload.data[0]; |
33941284 | 436 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 DH |
437 | desc.tfm = call->conn->cipher; |
438 | desc.info = iv.x; | |
439 | desc.flags = 0; | |
440 | ||
441 | crypto_blkcipher_decrypt_iv(&desc, sg, sg, skb->len); | |
442 | if (sg != _sg) | |
443 | kfree(sg); | |
444 | ||
445 | /* remove the decrypted packet length */ | |
446 | if (skb_copy_bits(skb, 0, &sechdr, sizeof(sechdr)) < 0) | |
447 | goto datalen_error; | |
448 | if (!skb_pull(skb, sizeof(sechdr))) | |
449 | BUG(); | |
450 | ||
451 | buf = ntohl(sechdr.data_size); | |
452 | data_size = buf & 0xffff; | |
453 | ||
454 | check = buf >> 16; | |
0d12f8a4 | 455 | check ^= sp->hdr.seq ^ sp->hdr.callNumber; |
17926a79 DH |
456 | check &= 0xffff; |
457 | if (check != 0) { | |
458 | *_abort_code = RXKADSEALEDINCON; | |
459 | goto protocol_error; | |
460 | } | |
461 | ||
462 | /* shorten the packet to remove the padding */ | |
463 | if (data_size > skb->len) | |
464 | goto datalen_error; | |
465 | else if (data_size < skb->len) | |
466 | skb->len = data_size; | |
467 | ||
468 | _leave(" = 0 [dlen=%x]", data_size); | |
469 | return 0; | |
470 | ||
471 | datalen_error: | |
472 | *_abort_code = RXKADDATALEN; | |
473 | protocol_error: | |
474 | _leave(" = -EPROTO"); | |
475 | return -EPROTO; | |
476 | ||
477 | nomem: | |
478 | _leave(" = -ENOMEM"); | |
479 | return -ENOMEM; | |
480 | } | |
481 | ||
482 | /* | |
483 | * verify the security on a received packet | |
484 | */ | |
485 | static int rxkad_verify_packet(const struct rxrpc_call *call, | |
486 | struct sk_buff *skb, | |
487 | u32 *_abort_code) | |
488 | { | |
489 | struct blkcipher_desc desc; | |
490 | struct rxrpc_skb_priv *sp; | |
491 | struct rxrpc_crypt iv; | |
492 | struct scatterlist sg[2]; | |
493 | struct { | |
494 | __be32 x[2]; | |
495 | } tmpbuf __attribute__((aligned(8))); /* must all be in same page */ | |
0d12f8a4 DH |
496 | u16 cksum; |
497 | u32 x, y; | |
17926a79 DH |
498 | int ret; |
499 | ||
500 | sp = rxrpc_skb(skb); | |
501 | ||
502 | _enter("{%d{%x}},{#%u}", | |
0d12f8a4 | 503 | call->debug_id, key_serial(call->conn->key), sp->hdr.seq); |
17926a79 DH |
504 | |
505 | if (!call->conn->cipher) | |
506 | return 0; | |
507 | ||
8b815477 | 508 | if (sp->hdr.securityIndex != RXRPC_SECURITY_RXKAD) { |
17926a79 DH |
509 | *_abort_code = RXKADINCONSISTENCY; |
510 | _leave(" = -EPROTO [not rxkad]"); | |
511 | return -EPROTO; | |
512 | } | |
513 | ||
514 | /* continue encrypting from where we left off */ | |
515 | memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); | |
516 | desc.tfm = call->conn->cipher; | |
517 | desc.info = iv.x; | |
518 | desc.flags = 0; | |
519 | ||
520 | /* validate the security checksum */ | |
0d12f8a4 DH |
521 | x = call->channel << (32 - RXRPC_CIDSHIFT); |
522 | x |= sp->hdr.seq & 0x3fffffff; | |
523 | tmpbuf.x[0] = htonl(call->call_id); | |
524 | tmpbuf.x[1] = htonl(x); | |
17926a79 | 525 | |
68e3f5dd HX |
526 | sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf)); |
527 | sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf)); | |
17926a79 DH |
528 | crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf)); |
529 | ||
91e916cf | 530 | y = ntohl(tmpbuf.x[1]); |
0d12f8a4 DH |
531 | cksum = (y >> 16) & 0xffff; |
532 | if (cksum == 0) | |
533 | cksum = 1; /* zero checksums are not permitted */ | |
17926a79 | 534 | |
17926a79 DH |
535 | if (sp->hdr.cksum != cksum) { |
536 | *_abort_code = RXKADSEALEDINCON; | |
537 | _leave(" = -EPROTO [csum failed]"); | |
538 | return -EPROTO; | |
539 | } | |
540 | ||
541 | switch (call->conn->security_level) { | |
542 | case RXRPC_SECURITY_PLAIN: | |
543 | ret = 0; | |
544 | break; | |
545 | case RXRPC_SECURITY_AUTH: | |
546 | ret = rxkad_verify_packet_auth(call, skb, _abort_code); | |
547 | break; | |
548 | case RXRPC_SECURITY_ENCRYPT: | |
549 | ret = rxkad_verify_packet_encrypt(call, skb, _abort_code); | |
550 | break; | |
551 | default: | |
552 | ret = -ENOANO; | |
553 | break; | |
554 | } | |
555 | ||
556 | _leave(" = %d", ret); | |
557 | return ret; | |
558 | } | |
559 | ||
560 | /* | |
561 | * issue a challenge | |
562 | */ | |
563 | static int rxkad_issue_challenge(struct rxrpc_connection *conn) | |
564 | { | |
565 | struct rxkad_challenge challenge; | |
0d12f8a4 | 566 | struct rxrpc_wire_header whdr; |
17926a79 DH |
567 | struct msghdr msg; |
568 | struct kvec iov[2]; | |
569 | size_t len; | |
0d12f8a4 | 570 | u32 serial; |
17926a79 DH |
571 | int ret; |
572 | ||
573 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->key)); | |
574 | ||
575 | ret = key_validate(conn->key); | |
576 | if (ret < 0) | |
577 | return ret; | |
578 | ||
579 | get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce)); | |
580 | ||
581 | challenge.version = htonl(2); | |
582 | challenge.nonce = htonl(conn->security_nonce); | |
583 | challenge.min_level = htonl(0); | |
584 | challenge.__padding = 0; | |
585 | ||
586 | msg.msg_name = &conn->trans->peer->srx.transport.sin; | |
587 | msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin); | |
588 | msg.msg_control = NULL; | |
589 | msg.msg_controllen = 0; | |
590 | msg.msg_flags = 0; | |
591 | ||
0d12f8a4 DH |
592 | whdr.epoch = htonl(conn->epoch); |
593 | whdr.cid = htonl(conn->cid); | |
594 | whdr.callNumber = 0; | |
595 | whdr.seq = 0; | |
596 | whdr.type = RXRPC_PACKET_TYPE_CHALLENGE; | |
597 | whdr.flags = conn->out_clientflag; | |
598 | whdr.userStatus = 0; | |
599 | whdr.securityIndex = conn->security_ix; | |
600 | whdr._rsvd = 0; | |
601 | whdr.serviceId = htons(conn->service_id); | |
602 | ||
603 | iov[0].iov_base = &whdr; | |
604 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
605 | iov[1].iov_base = &challenge; |
606 | iov[1].iov_len = sizeof(challenge); | |
607 | ||
608 | len = iov[0].iov_len + iov[1].iov_len; | |
609 | ||
0d12f8a4 DH |
610 | serial = atomic_inc_return(&conn->serial); |
611 | whdr.serial = htonl(serial); | |
612 | _proto("Tx CHALLENGE %%%u", serial); | |
17926a79 DH |
613 | |
614 | ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len); | |
615 | if (ret < 0) { | |
616 | _debug("sendmsg failed: %d", ret); | |
617 | return -EAGAIN; | |
618 | } | |
619 | ||
620 | _leave(" = 0"); | |
621 | return 0; | |
622 | } | |
623 | ||
624 | /* | |
625 | * send a Kerberos security response | |
626 | */ | |
627 | static int rxkad_send_response(struct rxrpc_connection *conn, | |
0d12f8a4 | 628 | struct rxrpc_host_header *hdr, |
17926a79 DH |
629 | struct rxkad_response *resp, |
630 | const struct rxkad_key *s2) | |
631 | { | |
0d12f8a4 | 632 | struct rxrpc_wire_header whdr; |
17926a79 DH |
633 | struct msghdr msg; |
634 | struct kvec iov[3]; | |
635 | size_t len; | |
0d12f8a4 | 636 | u32 serial; |
17926a79 DH |
637 | int ret; |
638 | ||
639 | _enter(""); | |
640 | ||
641 | msg.msg_name = &conn->trans->peer->srx.transport.sin; | |
642 | msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin); | |
643 | msg.msg_control = NULL; | |
644 | msg.msg_controllen = 0; | |
645 | msg.msg_flags = 0; | |
646 | ||
0d12f8a4 DH |
647 | memset(&whdr, 0, sizeof(whdr)); |
648 | whdr.epoch = htonl(hdr->epoch); | |
649 | whdr.cid = htonl(hdr->cid); | |
650 | whdr.type = RXRPC_PACKET_TYPE_RESPONSE; | |
651 | whdr.flags = conn->out_clientflag; | |
652 | whdr.securityIndex = hdr->securityIndex; | |
653 | whdr.serviceId = htons(hdr->serviceId); | |
17926a79 | 654 | |
0d12f8a4 DH |
655 | iov[0].iov_base = &whdr; |
656 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
657 | iov[1].iov_base = resp; |
658 | iov[1].iov_len = sizeof(*resp); | |
0d12f8a4 | 659 | iov[2].iov_base = (void *)s2->ticket; |
17926a79 DH |
660 | iov[2].iov_len = s2->ticket_len; |
661 | ||
662 | len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len; | |
663 | ||
0d12f8a4 DH |
664 | serial = atomic_inc_return(&conn->serial); |
665 | whdr.serial = htonl(serial); | |
666 | _proto("Tx RESPONSE %%%u", serial); | |
17926a79 DH |
667 | |
668 | ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 3, len); | |
669 | if (ret < 0) { | |
670 | _debug("sendmsg failed: %d", ret); | |
671 | return -EAGAIN; | |
672 | } | |
673 | ||
674 | _leave(" = 0"); | |
675 | return 0; | |
676 | } | |
677 | ||
678 | /* | |
679 | * calculate the response checksum | |
680 | */ | |
681 | static void rxkad_calc_response_checksum(struct rxkad_response *response) | |
682 | { | |
683 | u32 csum = 1000003; | |
684 | int loop; | |
685 | u8 *p = (u8 *) response; | |
686 | ||
687 | for (loop = sizeof(*response); loop > 0; loop--) | |
688 | csum = csum * 0x10204081 + *p++; | |
689 | ||
690 | response->encrypted.checksum = htonl(csum); | |
691 | } | |
692 | ||
693 | /* | |
694 | * load a scatterlist with a potentially split-page buffer | |
695 | */ | |
696 | static void rxkad_sg_set_buf2(struct scatterlist sg[2], | |
697 | void *buf, size_t buflen) | |
698 | { | |
68e3f5dd | 699 | int nsg = 1; |
17926a79 | 700 | |
68e3f5dd | 701 | sg_init_table(sg, 2); |
17926a79 DH |
702 | |
703 | sg_set_buf(&sg[0], buf, buflen); | |
704 | if (sg[0].offset + buflen > PAGE_SIZE) { | |
705 | /* the buffer was split over two pages */ | |
706 | sg[0].length = PAGE_SIZE - sg[0].offset; | |
707 | sg_set_buf(&sg[1], buf + sg[0].length, buflen - sg[0].length); | |
68e3f5dd | 708 | nsg++; |
17926a79 DH |
709 | } |
710 | ||
c46f2334 | 711 | sg_mark_end(&sg[nsg - 1]); |
68e3f5dd | 712 | |
17926a79 DH |
713 | ASSERTCMP(sg[0].length + sg[1].length, ==, buflen); |
714 | } | |
715 | ||
716 | /* | |
717 | * encrypt the response packet | |
718 | */ | |
719 | static void rxkad_encrypt_response(struct rxrpc_connection *conn, | |
720 | struct rxkad_response *resp, | |
721 | const struct rxkad_key *s2) | |
722 | { | |
723 | struct blkcipher_desc desc; | |
724 | struct rxrpc_crypt iv; | |
68e3f5dd | 725 | struct scatterlist sg[2]; |
17926a79 DH |
726 | |
727 | /* continue encrypting from where we left off */ | |
728 | memcpy(&iv, s2->session_key, sizeof(iv)); | |
729 | desc.tfm = conn->cipher; | |
730 | desc.info = iv.x; | |
731 | desc.flags = 0; | |
732 | ||
68e3f5dd HX |
733 | rxkad_sg_set_buf2(sg, &resp->encrypted, sizeof(resp->encrypted)); |
734 | crypto_blkcipher_encrypt_iv(&desc, sg, sg, sizeof(resp->encrypted)); | |
17926a79 DH |
735 | } |
736 | ||
737 | /* | |
738 | * respond to a challenge packet | |
739 | */ | |
740 | static int rxkad_respond_to_challenge(struct rxrpc_connection *conn, | |
741 | struct sk_buff *skb, | |
742 | u32 *_abort_code) | |
743 | { | |
33941284 | 744 | const struct rxrpc_key_token *token; |
17926a79 DH |
745 | struct rxkad_challenge challenge; |
746 | struct rxkad_response resp | |
747 | __attribute__((aligned(8))); /* must be aligned for crypto */ | |
748 | struct rxrpc_skb_priv *sp; | |
749 | u32 version, nonce, min_level, abort_code; | |
750 | int ret; | |
751 | ||
752 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->key)); | |
753 | ||
754 | if (!conn->key) { | |
755 | _leave(" = -EPROTO [no key]"); | |
756 | return -EPROTO; | |
757 | } | |
758 | ||
759 | ret = key_validate(conn->key); | |
760 | if (ret < 0) { | |
761 | *_abort_code = RXKADEXPIRED; | |
762 | return ret; | |
763 | } | |
764 | ||
765 | abort_code = RXKADPACKETSHORT; | |
766 | sp = rxrpc_skb(skb); | |
767 | if (skb_copy_bits(skb, 0, &challenge, sizeof(challenge)) < 0) | |
768 | goto protocol_error; | |
769 | ||
770 | version = ntohl(challenge.version); | |
771 | nonce = ntohl(challenge.nonce); | |
772 | min_level = ntohl(challenge.min_level); | |
773 | ||
774 | _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }", | |
0d12f8a4 | 775 | sp->hdr.serial, version, nonce, min_level); |
17926a79 DH |
776 | |
777 | abort_code = RXKADINCONSISTENCY; | |
778 | if (version != RXKAD_VERSION) | |
779 | goto protocol_error; | |
780 | ||
781 | abort_code = RXKADLEVELFAIL; | |
782 | if (conn->security_level < min_level) | |
783 | goto protocol_error; | |
784 | ||
146aa8b1 | 785 | token = conn->key->payload.data[0]; |
17926a79 DH |
786 | |
787 | /* build the response packet */ | |
788 | memset(&resp, 0, sizeof(resp)); | |
789 | ||
098a2099 DH |
790 | resp.version = htonl(RXKAD_VERSION); |
791 | resp.encrypted.epoch = htonl(conn->epoch); | |
792 | resp.encrypted.cid = htonl(conn->cid); | |
793 | resp.encrypted.securityIndex = htonl(conn->security_ix); | |
794 | resp.encrypted.inc_nonce = htonl(nonce + 1); | |
795 | resp.encrypted.level = htonl(conn->security_level); | |
796 | resp.kvno = htonl(token->kad->kvno); | |
797 | resp.ticket_len = htonl(token->kad->ticket_len); | |
798 | ||
17926a79 | 799 | resp.encrypted.call_id[0] = |
0d12f8a4 | 800 | htonl(conn->channels[0] ? conn->channels[0]->call_id : 0); |
17926a79 | 801 | resp.encrypted.call_id[1] = |
0d12f8a4 | 802 | htonl(conn->channels[1] ? conn->channels[1]->call_id : 0); |
17926a79 | 803 | resp.encrypted.call_id[2] = |
0d12f8a4 | 804 | htonl(conn->channels[2] ? conn->channels[2]->call_id : 0); |
17926a79 | 805 | resp.encrypted.call_id[3] = |
0d12f8a4 | 806 | htonl(conn->channels[3] ? conn->channels[3]->call_id : 0); |
17926a79 DH |
807 | |
808 | /* calculate the response checksum and then do the encryption */ | |
809 | rxkad_calc_response_checksum(&resp); | |
33941284 DH |
810 | rxkad_encrypt_response(conn, &resp, token->kad); |
811 | return rxkad_send_response(conn, &sp->hdr, &resp, token->kad); | |
17926a79 DH |
812 | |
813 | protocol_error: | |
814 | *_abort_code = abort_code; | |
815 | _leave(" = -EPROTO [%d]", abort_code); | |
816 | return -EPROTO; | |
817 | } | |
818 | ||
819 | /* | |
820 | * decrypt the kerberos IV ticket in the response | |
821 | */ | |
822 | static int rxkad_decrypt_ticket(struct rxrpc_connection *conn, | |
823 | void *ticket, size_t ticket_len, | |
824 | struct rxrpc_crypt *_session_key, | |
825 | time_t *_expiry, | |
826 | u32 *_abort_code) | |
827 | { | |
828 | struct blkcipher_desc desc; | |
829 | struct rxrpc_crypt iv, key; | |
68e3f5dd | 830 | struct scatterlist sg[1]; |
17926a79 | 831 | struct in_addr addr; |
95c96174 | 832 | unsigned int life; |
17926a79 DH |
833 | time_t issue, now; |
834 | bool little_endian; | |
835 | int ret; | |
836 | u8 *p, *q, *name, *end; | |
837 | ||
838 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key)); | |
839 | ||
840 | *_expiry = 0; | |
841 | ||
842 | ret = key_validate(conn->server_key); | |
843 | if (ret < 0) { | |
844 | switch (ret) { | |
845 | case -EKEYEXPIRED: | |
846 | *_abort_code = RXKADEXPIRED; | |
847 | goto error; | |
848 | default: | |
849 | *_abort_code = RXKADNOAUTH; | |
850 | goto error; | |
851 | } | |
852 | } | |
853 | ||
146aa8b1 | 854 | ASSERT(conn->server_key->payload.data[0] != NULL); |
17926a79 DH |
855 | ASSERTCMP((unsigned long) ticket & 7UL, ==, 0); |
856 | ||
146aa8b1 | 857 | memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv)); |
17926a79 | 858 | |
146aa8b1 | 859 | desc.tfm = conn->server_key->payload.data[0]; |
17926a79 DH |
860 | desc.info = iv.x; |
861 | desc.flags = 0; | |
862 | ||
68e3f5dd HX |
863 | sg_init_one(&sg[0], ticket, ticket_len); |
864 | crypto_blkcipher_decrypt_iv(&desc, sg, sg, ticket_len); | |
17926a79 DH |
865 | |
866 | p = ticket; | |
867 | end = p + ticket_len; | |
868 | ||
869 | #define Z(size) \ | |
870 | ({ \ | |
871 | u8 *__str = p; \ | |
872 | q = memchr(p, 0, end - p); \ | |
873 | if (!q || q - p > (size)) \ | |
874 | goto bad_ticket; \ | |
875 | for (; p < q; p++) \ | |
876 | if (!isprint(*p)) \ | |
877 | goto bad_ticket; \ | |
878 | p++; \ | |
879 | __str; \ | |
880 | }) | |
881 | ||
882 | /* extract the ticket flags */ | |
883 | _debug("KIV FLAGS: %x", *p); | |
884 | little_endian = *p & 1; | |
885 | p++; | |
886 | ||
887 | /* extract the authentication name */ | |
888 | name = Z(ANAME_SZ); | |
889 | _debug("KIV ANAME: %s", name); | |
890 | ||
891 | /* extract the principal's instance */ | |
892 | name = Z(INST_SZ); | |
893 | _debug("KIV INST : %s", name); | |
894 | ||
895 | /* extract the principal's authentication domain */ | |
896 | name = Z(REALM_SZ); | |
897 | _debug("KIV REALM: %s", name); | |
898 | ||
899 | if (end - p < 4 + 8 + 4 + 2) | |
900 | goto bad_ticket; | |
901 | ||
902 | /* get the IPv4 address of the entity that requested the ticket */ | |
903 | memcpy(&addr, p, sizeof(addr)); | |
904 | p += 4; | |
21454aaa | 905 | _debug("KIV ADDR : %pI4", &addr); |
17926a79 DH |
906 | |
907 | /* get the session key from the ticket */ | |
908 | memcpy(&key, p, sizeof(key)); | |
909 | p += 8; | |
910 | _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1])); | |
911 | memcpy(_session_key, &key, sizeof(key)); | |
912 | ||
913 | /* get the ticket's lifetime */ | |
914 | life = *p++ * 5 * 60; | |
915 | _debug("KIV LIFE : %u", life); | |
916 | ||
917 | /* get the issue time of the ticket */ | |
918 | if (little_endian) { | |
919 | __le32 stamp; | |
920 | memcpy(&stamp, p, 4); | |
921 | issue = le32_to_cpu(stamp); | |
922 | } else { | |
923 | __be32 stamp; | |
924 | memcpy(&stamp, p, 4); | |
925 | issue = be32_to_cpu(stamp); | |
926 | } | |
927 | p += 4; | |
2c6b47de | 928 | now = get_seconds(); |
17926a79 DH |
929 | _debug("KIV ISSUE: %lx [%lx]", issue, now); |
930 | ||
931 | /* check the ticket is in date */ | |
932 | if (issue > now) { | |
933 | *_abort_code = RXKADNOAUTH; | |
934 | ret = -EKEYREJECTED; | |
935 | goto error; | |
936 | } | |
937 | ||
938 | if (issue < now - life) { | |
939 | *_abort_code = RXKADEXPIRED; | |
940 | ret = -EKEYEXPIRED; | |
941 | goto error; | |
942 | } | |
943 | ||
944 | *_expiry = issue + life; | |
945 | ||
946 | /* get the service name */ | |
947 | name = Z(SNAME_SZ); | |
948 | _debug("KIV SNAME: %s", name); | |
949 | ||
950 | /* get the service instance name */ | |
951 | name = Z(INST_SZ); | |
952 | _debug("KIV SINST: %s", name); | |
953 | ||
954 | ret = 0; | |
955 | error: | |
956 | _leave(" = %d", ret); | |
957 | return ret; | |
958 | ||
959 | bad_ticket: | |
960 | *_abort_code = RXKADBADTICKET; | |
961 | ret = -EBADMSG; | |
962 | goto error; | |
963 | } | |
964 | ||
965 | /* | |
966 | * decrypt the response packet | |
967 | */ | |
968 | static void rxkad_decrypt_response(struct rxrpc_connection *conn, | |
969 | struct rxkad_response *resp, | |
970 | const struct rxrpc_crypt *session_key) | |
971 | { | |
972 | struct blkcipher_desc desc; | |
68e3f5dd | 973 | struct scatterlist sg[2]; |
17926a79 DH |
974 | struct rxrpc_crypt iv; |
975 | ||
976 | _enter(",,%08x%08x", | |
977 | ntohl(session_key->n[0]), ntohl(session_key->n[1])); | |
978 | ||
979 | ASSERT(rxkad_ci != NULL); | |
980 | ||
981 | mutex_lock(&rxkad_ci_mutex); | |
982 | if (crypto_blkcipher_setkey(rxkad_ci, session_key->x, | |
983 | sizeof(*session_key)) < 0) | |
984 | BUG(); | |
985 | ||
986 | memcpy(&iv, session_key, sizeof(iv)); | |
987 | desc.tfm = rxkad_ci; | |
988 | desc.info = iv.x; | |
989 | desc.flags = 0; | |
990 | ||
68e3f5dd HX |
991 | rxkad_sg_set_buf2(sg, &resp->encrypted, sizeof(resp->encrypted)); |
992 | crypto_blkcipher_decrypt_iv(&desc, sg, sg, sizeof(resp->encrypted)); | |
17926a79 DH |
993 | mutex_unlock(&rxkad_ci_mutex); |
994 | ||
995 | _leave(""); | |
996 | } | |
997 | ||
998 | /* | |
999 | * verify a response | |
1000 | */ | |
1001 | static int rxkad_verify_response(struct rxrpc_connection *conn, | |
1002 | struct sk_buff *skb, | |
1003 | u32 *_abort_code) | |
1004 | { | |
1005 | struct rxkad_response response | |
1006 | __attribute__((aligned(8))); /* must be aligned for crypto */ | |
1007 | struct rxrpc_skb_priv *sp; | |
1008 | struct rxrpc_crypt session_key; | |
1009 | time_t expiry; | |
1010 | void *ticket; | |
91e916cf AV |
1011 | u32 abort_code, version, kvno, ticket_len, level; |
1012 | __be32 csum; | |
17926a79 DH |
1013 | int ret; |
1014 | ||
1015 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key)); | |
1016 | ||
1017 | abort_code = RXKADPACKETSHORT; | |
1018 | if (skb_copy_bits(skb, 0, &response, sizeof(response)) < 0) | |
1019 | goto protocol_error; | |
1020 | if (!pskb_pull(skb, sizeof(response))) | |
1021 | BUG(); | |
1022 | ||
1023 | version = ntohl(response.version); | |
1024 | ticket_len = ntohl(response.ticket_len); | |
1025 | kvno = ntohl(response.kvno); | |
1026 | sp = rxrpc_skb(skb); | |
1027 | _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }", | |
0d12f8a4 | 1028 | sp->hdr.serial, version, kvno, ticket_len); |
17926a79 DH |
1029 | |
1030 | abort_code = RXKADINCONSISTENCY; | |
1031 | if (version != RXKAD_VERSION) | |
4aa9cb32 | 1032 | goto protocol_error; |
17926a79 DH |
1033 | |
1034 | abort_code = RXKADTICKETLEN; | |
1035 | if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN) | |
1036 | goto protocol_error; | |
1037 | ||
1038 | abort_code = RXKADUNKNOWNKEY; | |
1039 | if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5) | |
1040 | goto protocol_error; | |
1041 | ||
1042 | /* extract the kerberos ticket and decrypt and decode it */ | |
1043 | ticket = kmalloc(ticket_len, GFP_NOFS); | |
1044 | if (!ticket) | |
1045 | return -ENOMEM; | |
1046 | ||
1047 | abort_code = RXKADPACKETSHORT; | |
1048 | if (skb_copy_bits(skb, 0, ticket, ticket_len) < 0) | |
1049 | goto protocol_error_free; | |
1050 | ||
1051 | ret = rxkad_decrypt_ticket(conn, ticket, ticket_len, &session_key, | |
1052 | &expiry, &abort_code); | |
1053 | if (ret < 0) { | |
1054 | *_abort_code = abort_code; | |
1055 | kfree(ticket); | |
1056 | return ret; | |
1057 | } | |
1058 | ||
1059 | /* use the session key from inside the ticket to decrypt the | |
1060 | * response */ | |
1061 | rxkad_decrypt_response(conn, &response, &session_key); | |
1062 | ||
1063 | abort_code = RXKADSEALEDINCON; | |
0d12f8a4 | 1064 | if (ntohl(response.encrypted.epoch) != conn->epoch) |
17926a79 | 1065 | goto protocol_error_free; |
0d12f8a4 | 1066 | if (ntohl(response.encrypted.cid) != conn->cid) |
17926a79 DH |
1067 | goto protocol_error_free; |
1068 | if (ntohl(response.encrypted.securityIndex) != conn->security_ix) | |
1069 | goto protocol_error_free; | |
1070 | csum = response.encrypted.checksum; | |
1071 | response.encrypted.checksum = 0; | |
1072 | rxkad_calc_response_checksum(&response); | |
1073 | if (response.encrypted.checksum != csum) | |
1074 | goto protocol_error_free; | |
1075 | ||
1076 | if (ntohl(response.encrypted.call_id[0]) > INT_MAX || | |
1077 | ntohl(response.encrypted.call_id[1]) > INT_MAX || | |
1078 | ntohl(response.encrypted.call_id[2]) > INT_MAX || | |
1079 | ntohl(response.encrypted.call_id[3]) > INT_MAX) | |
1080 | goto protocol_error_free; | |
1081 | ||
1082 | abort_code = RXKADOUTOFSEQUENCE; | |
0d12f8a4 | 1083 | if (ntohl(response.encrypted.inc_nonce) != conn->security_nonce + 1) |
17926a79 DH |
1084 | goto protocol_error_free; |
1085 | ||
1086 | abort_code = RXKADLEVELFAIL; | |
1087 | level = ntohl(response.encrypted.level); | |
1088 | if (level > RXRPC_SECURITY_ENCRYPT) | |
1089 | goto protocol_error_free; | |
1090 | conn->security_level = level; | |
1091 | ||
1092 | /* create a key to hold the security data and expiration time - after | |
1093 | * this the connection security can be handled in exactly the same way | |
1094 | * as for a client connection */ | |
1095 | ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno); | |
1096 | if (ret < 0) { | |
1097 | kfree(ticket); | |
1098 | return ret; | |
1099 | } | |
1100 | ||
1101 | kfree(ticket); | |
1102 | _leave(" = 0"); | |
1103 | return 0; | |
1104 | ||
1105 | protocol_error_free: | |
1106 | kfree(ticket); | |
1107 | protocol_error: | |
1108 | *_abort_code = abort_code; | |
1109 | _leave(" = -EPROTO [%d]", abort_code); | |
1110 | return -EPROTO; | |
1111 | } | |
1112 | ||
1113 | /* | |
1114 | * clear the connection security | |
1115 | */ | |
1116 | static void rxkad_clear(struct rxrpc_connection *conn) | |
1117 | { | |
1118 | _enter(""); | |
1119 | ||
1120 | if (conn->cipher) | |
1121 | crypto_free_blkcipher(conn->cipher); | |
1122 | } | |
1123 | ||
1124 | /* | |
1125 | * RxRPC Kerberos-based security | |
1126 | */ | |
1127 | static struct rxrpc_security rxkad = { | |
1128 | .owner = THIS_MODULE, | |
1129 | .name = "rxkad", | |
8b815477 | 1130 | .security_index = RXRPC_SECURITY_RXKAD, |
17926a79 DH |
1131 | .init_connection_security = rxkad_init_connection_security, |
1132 | .prime_packet_security = rxkad_prime_packet_security, | |
1133 | .secure_packet = rxkad_secure_packet, | |
1134 | .verify_packet = rxkad_verify_packet, | |
1135 | .issue_challenge = rxkad_issue_challenge, | |
1136 | .respond_to_challenge = rxkad_respond_to_challenge, | |
1137 | .verify_response = rxkad_verify_response, | |
1138 | .clear = rxkad_clear, | |
1139 | }; | |
1140 | ||
1141 | static __init int rxkad_init(void) | |
1142 | { | |
1143 | _enter(""); | |
1144 | ||
1145 | /* pin the cipher we need so that the crypto layer doesn't invoke | |
1146 | * keventd to go get it */ | |
1147 | rxkad_ci = crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC); | |
1148 | if (IS_ERR(rxkad_ci)) | |
1149 | return PTR_ERR(rxkad_ci); | |
1150 | ||
1151 | return rxrpc_register_security(&rxkad); | |
1152 | } | |
1153 | ||
1154 | module_init(rxkad_init); | |
1155 | ||
1156 | static __exit void rxkad_exit(void) | |
1157 | { | |
1158 | _enter(""); | |
1159 | ||
1160 | rxrpc_unregister_security(&rxkad); | |
1161 | crypto_free_blkcipher(rxkad_ci); | |
1162 | } | |
1163 | ||
1164 | module_exit(rxkad_exit); |