Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
17926a79 DH |
2 | /* Kerberos-based RxRPC security |
3 | * | |
4 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
17926a79 DH |
6 | */ |
7 | ||
9b6d5398 JP |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
1afe593b | 10 | #include <crypto/skcipher.h> |
17926a79 DH |
11 | #include <linux/module.h> |
12 | #include <linux/net.h> | |
13 | #include <linux/skbuff.h> | |
14 | #include <linux/udp.h> | |
17926a79 DH |
15 | #include <linux/scatterlist.h> |
16 | #include <linux/ctype.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
17926a79 DH |
18 | #include <net/sock.h> |
19 | #include <net/af_rxrpc.h> | |
33941284 | 20 | #include <keys/rxrpc-type.h> |
17926a79 DH |
21 | #include "ar-internal.h" |
22 | ||
23 | #define RXKAD_VERSION 2 | |
24 | #define MAXKRB5TICKETLEN 1024 | |
25 | #define RXKAD_TKT_TYPE_KERBEROS_V5 256 | |
26 | #define ANAME_SZ 40 /* size of authentication name */ | |
27 | #define INST_SZ 40 /* size of principal's instance */ | |
28 | #define REALM_SZ 40 /* size of principal's auth domain */ | |
29 | #define SNAME_SZ 40 /* size of service name */ | |
30 | ||
17926a79 DH |
31 | struct rxkad_level1_hdr { |
32 | __be32 data_size; /* true data size (excluding padding) */ | |
33 | }; | |
34 | ||
35 | struct rxkad_level2_hdr { | |
36 | __be32 data_size; /* true data size (excluding padding) */ | |
37 | __be32 checksum; /* decrypted data checksum */ | |
38 | }; | |
39 | ||
17926a79 DH |
40 | /* |
41 | * this holds a pinned cipher so that keventd doesn't get called by the cipher | |
42 | * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE | |
43 | * packets | |
44 | */ | |
69d826fa | 45 | static struct crypto_sync_skcipher *rxkad_ci; |
1db88c53 | 46 | static struct skcipher_request *rxkad_ci_req; |
17926a79 DH |
47 | static DEFINE_MUTEX(rxkad_ci_mutex); |
48 | ||
49 | /* | |
50 | * initialise connection security | |
51 | */ | |
52 | static int rxkad_init_connection_security(struct rxrpc_connection *conn) | |
53 | { | |
69d826fa | 54 | struct crypto_sync_skcipher *ci; |
33941284 | 55 | struct rxrpc_key_token *token; |
17926a79 DH |
56 | int ret; |
57 | ||
19ffa01c | 58 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 59 | |
19ffa01c | 60 | token = conn->params.key->payload.data[0]; |
33941284 | 61 | conn->security_ix = token->security_index; |
17926a79 | 62 | |
69d826fa | 63 | ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0); |
17926a79 DH |
64 | if (IS_ERR(ci)) { |
65 | _debug("no cipher"); | |
66 | ret = PTR_ERR(ci); | |
67 | goto error; | |
68 | } | |
69 | ||
69d826fa | 70 | if (crypto_sync_skcipher_setkey(ci, token->kad->session_key, |
1afe593b | 71 | sizeof(token->kad->session_key)) < 0) |
17926a79 DH |
72 | BUG(); |
73 | ||
19ffa01c | 74 | switch (conn->params.security_level) { |
17926a79 DH |
75 | case RXRPC_SECURITY_PLAIN: |
76 | break; | |
77 | case RXRPC_SECURITY_AUTH: | |
78 | conn->size_align = 8; | |
79 | conn->security_size = sizeof(struct rxkad_level1_hdr); | |
17926a79 DH |
80 | break; |
81 | case RXRPC_SECURITY_ENCRYPT: | |
82 | conn->size_align = 8; | |
83 | conn->security_size = sizeof(struct rxkad_level2_hdr); | |
17926a79 DH |
84 | break; |
85 | default: | |
86 | ret = -EKEYREJECTED; | |
87 | goto error; | |
88 | } | |
89 | ||
90 | conn->cipher = ci; | |
91 | ret = 0; | |
92 | error: | |
93 | _leave(" = %d", ret); | |
94 | return ret; | |
95 | } | |
96 | ||
97 | /* | |
98 | * prime the encryption state with the invariant parts of a connection's | |
99 | * description | |
100 | */ | |
a263629d | 101 | static int rxkad_prime_packet_security(struct rxrpc_connection *conn) |
17926a79 | 102 | { |
1db88c53 | 103 | struct skcipher_request *req; |
33941284 | 104 | struct rxrpc_key_token *token; |
a263629d | 105 | struct scatterlist sg; |
17926a79 | 106 | struct rxrpc_crypt iv; |
a263629d HX |
107 | __be32 *tmpbuf; |
108 | size_t tmpsize = 4 * sizeof(__be32); | |
17926a79 DH |
109 | |
110 | _enter(""); | |
111 | ||
19ffa01c | 112 | if (!conn->params.key) |
a263629d HX |
113 | return 0; |
114 | ||
115 | tmpbuf = kmalloc(tmpsize, GFP_KERNEL); | |
116 | if (!tmpbuf) | |
117 | return -ENOMEM; | |
17926a79 | 118 | |
1db88c53 DH |
119 | req = skcipher_request_alloc(&conn->cipher->base, GFP_NOFS); |
120 | if (!req) { | |
121 | kfree(tmpbuf); | |
122 | return -ENOMEM; | |
123 | } | |
124 | ||
19ffa01c | 125 | token = conn->params.key->payload.data[0]; |
33941284 | 126 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 127 | |
a263629d HX |
128 | tmpbuf[0] = htonl(conn->proto.epoch); |
129 | tmpbuf[1] = htonl(conn->proto.cid); | |
130 | tmpbuf[2] = 0; | |
131 | tmpbuf[3] = htonl(conn->security_ix); | |
1afe593b | 132 | |
a263629d | 133 | sg_init_one(&sg, tmpbuf, tmpsize); |
69d826fa | 134 | skcipher_request_set_sync_tfm(req, conn->cipher); |
1afe593b | 135 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 136 | skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x); |
1afe593b | 137 | crypto_skcipher_encrypt(req); |
1db88c53 | 138 | skcipher_request_free(req); |
17926a79 | 139 | |
a263629d HX |
140 | memcpy(&conn->csum_iv, tmpbuf + 2, sizeof(conn->csum_iv)); |
141 | kfree(tmpbuf); | |
142 | _leave(" = 0"); | |
143 | return 0; | |
17926a79 DH |
144 | } |
145 | ||
1db88c53 DH |
146 | /* |
147 | * Allocate and prepare the crypto request on a call. For any particular call, | |
148 | * this is called serially for the packets, so no lock should be necessary. | |
149 | */ | |
150 | static struct skcipher_request *rxkad_get_call_crypto(struct rxrpc_call *call) | |
151 | { | |
152 | struct crypto_skcipher *tfm = &call->conn->cipher->base; | |
153 | struct skcipher_request *cipher_req = call->cipher_req; | |
154 | ||
155 | if (!cipher_req) { | |
156 | cipher_req = skcipher_request_alloc(tfm, GFP_NOFS); | |
157 | if (!cipher_req) | |
158 | return NULL; | |
159 | call->cipher_req = cipher_req; | |
160 | } | |
161 | ||
162 | return cipher_req; | |
163 | } | |
164 | ||
165 | /* | |
166 | * Clean up the crypto on a call. | |
167 | */ | |
168 | static void rxkad_free_call_crypto(struct rxrpc_call *call) | |
169 | { | |
170 | if (call->cipher_req) | |
171 | skcipher_request_free(call->cipher_req); | |
172 | call->cipher_req = NULL; | |
173 | } | |
174 | ||
17926a79 DH |
175 | /* |
176 | * partially encrypt a packet (level 1 security) | |
177 | */ | |
178 | static int rxkad_secure_packet_auth(const struct rxrpc_call *call, | |
179 | struct sk_buff *skb, | |
180 | u32 data_size, | |
54424d38 KC |
181 | void *sechdr, |
182 | struct skcipher_request *req) | |
17926a79 | 183 | { |
fb46f6ee | 184 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
a263629d | 185 | struct rxkad_level1_hdr hdr; |
17926a79 | 186 | struct rxrpc_crypt iv; |
a263629d | 187 | struct scatterlist sg; |
17926a79 DH |
188 | u16 check; |
189 | ||
17926a79 DH |
190 | _enter(""); |
191 | ||
5a924b89 | 192 | check = sp->hdr.seq ^ call->call_id; |
0d12f8a4 | 193 | data_size |= (u32)check << 16; |
17926a79 | 194 | |
a263629d HX |
195 | hdr.data_size = htonl(data_size); |
196 | memcpy(sechdr, &hdr, sizeof(hdr)); | |
17926a79 DH |
197 | |
198 | /* start the encryption afresh */ | |
199 | memset(&iv, 0, sizeof(iv)); | |
17926a79 | 200 | |
a263629d | 201 | sg_init_one(&sg, sechdr, 8); |
69d826fa | 202 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 203 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 204 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
205 | crypto_skcipher_encrypt(req); |
206 | skcipher_request_zero(req); | |
17926a79 | 207 | |
17926a79 DH |
208 | _leave(" = 0"); |
209 | return 0; | |
210 | } | |
211 | ||
212 | /* | |
213 | * wholly encrypt a packet (level 2 security) | |
214 | */ | |
215 | static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call, | |
b4f1342f DH |
216 | struct sk_buff *skb, |
217 | u32 data_size, | |
54424d38 KC |
218 | void *sechdr, |
219 | struct skcipher_request *req) | |
17926a79 | 220 | { |
33941284 | 221 | const struct rxrpc_key_token *token; |
a263629d | 222 | struct rxkad_level2_hdr rxkhdr; |
17926a79 | 223 | struct rxrpc_skb_priv *sp; |
17926a79 DH |
224 | struct rxrpc_crypt iv; |
225 | struct scatterlist sg[16]; | |
95c96174 | 226 | unsigned int len; |
17926a79 | 227 | u16 check; |
1afe593b | 228 | int err; |
17926a79 DH |
229 | |
230 | sp = rxrpc_skb(skb); | |
231 | ||
232 | _enter(""); | |
233 | ||
5a924b89 | 234 | check = sp->hdr.seq ^ call->call_id; |
17926a79 | 235 | |
0d12f8a4 | 236 | rxkhdr.data_size = htonl(data_size | (u32)check << 16); |
17926a79 | 237 | rxkhdr.checksum = 0; |
a263629d | 238 | memcpy(sechdr, &rxkhdr, sizeof(rxkhdr)); |
17926a79 DH |
239 | |
240 | /* encrypt from the session key */ | |
19ffa01c | 241 | token = call->conn->params.key->payload.data[0]; |
33941284 | 242 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 243 | |
68e3f5dd | 244 | sg_init_one(&sg[0], sechdr, sizeof(rxkhdr)); |
69d826fa | 245 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 246 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 247 | skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x); |
1afe593b | 248 | crypto_skcipher_encrypt(req); |
17926a79 DH |
249 | |
250 | /* we want to encrypt the skbuff in-place */ | |
d0d5c0cd DH |
251 | err = -EMSGSIZE; |
252 | if (skb_shinfo(skb)->nr_frags > 16) | |
1afe593b | 253 | goto out; |
17926a79 DH |
254 | |
255 | len = data_size + call->conn->size_align - 1; | |
256 | len &= ~(call->conn->size_align - 1); | |
257 | ||
d0d5c0cd | 258 | sg_init_table(sg, ARRAY_SIZE(sg)); |
89a5ea99 JD |
259 | err = skb_to_sgvec(skb, sg, 0, len); |
260 | if (unlikely(err < 0)) | |
261 | goto out; | |
1afe593b | 262 | skcipher_request_set_crypt(req, sg, sg, len, iv.x); |
1afe593b | 263 | crypto_skcipher_encrypt(req); |
17926a79 DH |
264 | |
265 | _leave(" = 0"); | |
1afe593b HX |
266 | err = 0; |
267 | ||
268 | out: | |
269 | skcipher_request_zero(req); | |
270 | return err; | |
17926a79 DH |
271 | } |
272 | ||
273 | /* | |
274 | * checksum an RxRPC packet header | |
275 | */ | |
a263629d | 276 | static int rxkad_secure_packet(struct rxrpc_call *call, |
b4f1342f DH |
277 | struct sk_buff *skb, |
278 | size_t data_size, | |
279 | void *sechdr) | |
17926a79 DH |
280 | { |
281 | struct rxrpc_skb_priv *sp; | |
1db88c53 | 282 | struct skcipher_request *req; |
17926a79 | 283 | struct rxrpc_crypt iv; |
a263629d | 284 | struct scatterlist sg; |
0d12f8a4 | 285 | u32 x, y; |
17926a79 DH |
286 | int ret; |
287 | ||
288 | sp = rxrpc_skb(skb); | |
289 | ||
290 | _enter("{%d{%x}},{#%u},%zu,", | |
19ffa01c DH |
291 | call->debug_id, key_serial(call->conn->params.key), |
292 | sp->hdr.seq, data_size); | |
17926a79 DH |
293 | |
294 | if (!call->conn->cipher) | |
295 | return 0; | |
296 | ||
19ffa01c | 297 | ret = key_validate(call->conn->params.key); |
17926a79 DH |
298 | if (ret < 0) |
299 | return ret; | |
300 | ||
1db88c53 DH |
301 | req = rxkad_get_call_crypto(call); |
302 | if (!req) | |
303 | return -ENOMEM; | |
304 | ||
17926a79 DH |
305 | /* continue encrypting from where we left off */ |
306 | memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); | |
17926a79 DH |
307 | |
308 | /* calculate the security checksum */ | |
01a90a45 | 309 | x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT); |
0d12f8a4 | 310 | x |= sp->hdr.seq & 0x3fffffff; |
5a924b89 | 311 | call->crypto_buf[0] = htonl(call->call_id); |
a263629d | 312 | call->crypto_buf[1] = htonl(x); |
1afe593b | 313 | |
a263629d | 314 | sg_init_one(&sg, call->crypto_buf, 8); |
69d826fa | 315 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 316 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 317 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
318 | crypto_skcipher_encrypt(req); |
319 | skcipher_request_zero(req); | |
17926a79 | 320 | |
a263629d | 321 | y = ntohl(call->crypto_buf[1]); |
91e916cf AV |
322 | y = (y >> 16) & 0xffff; |
323 | if (y == 0) | |
324 | y = 1; /* zero checksums are not permitted */ | |
0d12f8a4 | 325 | sp->hdr.cksum = y; |
17926a79 | 326 | |
19ffa01c | 327 | switch (call->conn->params.security_level) { |
17926a79 DH |
328 | case RXRPC_SECURITY_PLAIN: |
329 | ret = 0; | |
330 | break; | |
331 | case RXRPC_SECURITY_AUTH: | |
54424d38 KC |
332 | ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr, |
333 | req); | |
17926a79 DH |
334 | break; |
335 | case RXRPC_SECURITY_ENCRYPT: | |
336 | ret = rxkad_secure_packet_encrypt(call, skb, data_size, | |
54424d38 | 337 | sechdr, req); |
17926a79 DH |
338 | break; |
339 | default: | |
340 | ret = -EPERM; | |
341 | break; | |
342 | } | |
343 | ||
91e916cf | 344 | _leave(" = %d [set %hx]", ret, y); |
17926a79 DH |
345 | return ret; |
346 | } | |
347 | ||
348 | /* | |
349 | * decrypt partial encryption on a packet (level 1 security) | |
350 | */ | |
5a42976d | 351 | static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 352 | unsigned int offset, unsigned int len, |
54424d38 KC |
353 | rxrpc_seq_t seq, |
354 | struct skcipher_request *req) | |
17926a79 DH |
355 | { |
356 | struct rxkad_level1_hdr sechdr; | |
17926a79 | 357 | struct rxrpc_crypt iv; |
68e3f5dd | 358 | struct scatterlist sg[16]; |
fb46f6ee | 359 | bool aborted; |
17926a79 DH |
360 | u32 data_size, buf; |
361 | u16 check; | |
d0d5c0cd | 362 | int ret; |
17926a79 DH |
363 | |
364 | _enter(""); | |
365 | ||
248f219c | 366 | if (len < 8) { |
fb46f6ee DH |
367 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H", |
368 | RXKADSEALEDINCON); | |
5a42976d DH |
369 | goto protocol_error; |
370 | } | |
17926a79 | 371 | |
248f219c DH |
372 | /* Decrypt the skbuff in-place. TODO: We really want to decrypt |
373 | * directly into the target buffer. | |
374 | */ | |
d0d5c0cd | 375 | sg_init_table(sg, ARRAY_SIZE(sg)); |
89a5ea99 JD |
376 | ret = skb_to_sgvec(skb, sg, offset, 8); |
377 | if (unlikely(ret < 0)) | |
378 | return ret; | |
17926a79 DH |
379 | |
380 | /* start the decryption afresh */ | |
381 | memset(&iv, 0, sizeof(iv)); | |
17926a79 | 382 | |
69d826fa | 383 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b HX |
384 | skcipher_request_set_callback(req, 0, NULL, NULL); |
385 | skcipher_request_set_crypt(req, sg, sg, 8, iv.x); | |
1afe593b HX |
386 | crypto_skcipher_decrypt(req); |
387 | skcipher_request_zero(req); | |
17926a79 | 388 | |
5a42976d | 389 | /* Extract the decrypted packet length */ |
248f219c | 390 | if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) { |
fb46f6ee DH |
391 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1", |
392 | RXKADDATALEN); | |
5a42976d DH |
393 | goto protocol_error; |
394 | } | |
248f219c DH |
395 | offset += sizeof(sechdr); |
396 | len -= sizeof(sechdr); | |
17926a79 DH |
397 | |
398 | buf = ntohl(sechdr.data_size); | |
399 | data_size = buf & 0xffff; | |
400 | ||
401 | check = buf >> 16; | |
5a42976d | 402 | check ^= seq ^ call->call_id; |
17926a79 DH |
403 | check &= 0xffff; |
404 | if (check != 0) { | |
fb46f6ee DH |
405 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C", |
406 | RXKADSEALEDINCON); | |
17926a79 DH |
407 | goto protocol_error; |
408 | } | |
409 | ||
248f219c | 410 | if (data_size > len) { |
fb46f6ee DH |
411 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L", |
412 | RXKADDATALEN); | |
5a42976d DH |
413 | goto protocol_error; |
414 | } | |
17926a79 DH |
415 | |
416 | _leave(" = 0 [dlen=%x]", data_size); | |
417 | return 0; | |
418 | ||
17926a79 | 419 | protocol_error: |
fb46f6ee DH |
420 | if (aborted) |
421 | rxrpc_send_abort_packet(call); | |
17926a79 | 422 | return -EPROTO; |
17926a79 DH |
423 | } |
424 | ||
425 | /* | |
426 | * wholly decrypt a packet (level 2 security) | |
427 | */ | |
5a42976d | 428 | static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 429 | unsigned int offset, unsigned int len, |
54424d38 KC |
430 | rxrpc_seq_t seq, |
431 | struct skcipher_request *req) | |
17926a79 | 432 | { |
33941284 | 433 | const struct rxrpc_key_token *token; |
17926a79 | 434 | struct rxkad_level2_hdr sechdr; |
17926a79 DH |
435 | struct rxrpc_crypt iv; |
436 | struct scatterlist _sg[4], *sg; | |
fb46f6ee | 437 | bool aborted; |
17926a79 DH |
438 | u32 data_size, buf; |
439 | u16 check; | |
89a5ea99 | 440 | int nsg, ret; |
17926a79 DH |
441 | |
442 | _enter(",{%d}", skb->len); | |
443 | ||
248f219c | 444 | if (len < 8) { |
fb46f6ee DH |
445 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H", |
446 | RXKADSEALEDINCON); | |
5a42976d DH |
447 | goto protocol_error; |
448 | } | |
17926a79 | 449 | |
248f219c DH |
450 | /* Decrypt the skbuff in-place. TODO: We really want to decrypt |
451 | * directly into the target buffer. | |
452 | */ | |
17926a79 | 453 | sg = _sg; |
d0d5c0cd DH |
454 | nsg = skb_shinfo(skb)->nr_frags; |
455 | if (nsg <= 4) { | |
456 | nsg = 4; | |
457 | } else { | |
6da2ec56 | 458 | sg = kmalloc_array(nsg, sizeof(*sg), GFP_NOIO); |
17926a79 DH |
459 | if (!sg) |
460 | goto nomem; | |
461 | } | |
462 | ||
68e3f5dd | 463 | sg_init_table(sg, nsg); |
89a5ea99 JD |
464 | ret = skb_to_sgvec(skb, sg, offset, len); |
465 | if (unlikely(ret < 0)) { | |
466 | if (sg != _sg) | |
467 | kfree(sg); | |
468 | return ret; | |
469 | } | |
17926a79 DH |
470 | |
471 | /* decrypt from the session key */ | |
19ffa01c | 472 | token = call->conn->params.key->payload.data[0]; |
33941284 | 473 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 474 | |
69d826fa | 475 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 476 | skcipher_request_set_callback(req, 0, NULL, NULL); |
248f219c | 477 | skcipher_request_set_crypt(req, sg, sg, len, iv.x); |
1afe593b HX |
478 | crypto_skcipher_decrypt(req); |
479 | skcipher_request_zero(req); | |
17926a79 DH |
480 | if (sg != _sg) |
481 | kfree(sg); | |
482 | ||
5a42976d | 483 | /* Extract the decrypted packet length */ |
248f219c | 484 | if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) { |
fb46f6ee DH |
485 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2", |
486 | RXKADDATALEN); | |
5a42976d DH |
487 | goto protocol_error; |
488 | } | |
248f219c DH |
489 | offset += sizeof(sechdr); |
490 | len -= sizeof(sechdr); | |
17926a79 DH |
491 | |
492 | buf = ntohl(sechdr.data_size); | |
493 | data_size = buf & 0xffff; | |
494 | ||
495 | check = buf >> 16; | |
5a42976d | 496 | check ^= seq ^ call->call_id; |
17926a79 DH |
497 | check &= 0xffff; |
498 | if (check != 0) { | |
fb46f6ee DH |
499 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C", |
500 | RXKADSEALEDINCON); | |
17926a79 DH |
501 | goto protocol_error; |
502 | } | |
503 | ||
248f219c | 504 | if (data_size > len) { |
fb46f6ee DH |
505 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L", |
506 | RXKADDATALEN); | |
5a42976d DH |
507 | goto protocol_error; |
508 | } | |
17926a79 DH |
509 | |
510 | _leave(" = 0 [dlen=%x]", data_size); | |
511 | return 0; | |
512 | ||
17926a79 | 513 | protocol_error: |
fb46f6ee DH |
514 | if (aborted) |
515 | rxrpc_send_abort_packet(call); | |
17926a79 DH |
516 | return -EPROTO; |
517 | ||
518 | nomem: | |
519 | _leave(" = -ENOMEM"); | |
520 | return -ENOMEM; | |
521 | } | |
522 | ||
523 | /* | |
5a42976d DH |
524 | * Verify the security on a received packet or subpacket (if part of a |
525 | * jumbo packet). | |
17926a79 | 526 | */ |
5a42976d | 527 | static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 528 | unsigned int offset, unsigned int len, |
5a42976d | 529 | rxrpc_seq_t seq, u16 expected_cksum) |
17926a79 | 530 | { |
1db88c53 | 531 | struct skcipher_request *req; |
17926a79 | 532 | struct rxrpc_crypt iv; |
a263629d | 533 | struct scatterlist sg; |
fb46f6ee | 534 | bool aborted; |
0d12f8a4 DH |
535 | u16 cksum; |
536 | u32 x, y; | |
17926a79 DH |
537 | |
538 | _enter("{%d{%x}},{#%u}", | |
5a42976d | 539 | call->debug_id, key_serial(call->conn->params.key), seq); |
17926a79 DH |
540 | |
541 | if (!call->conn->cipher) | |
542 | return 0; | |
543 | ||
1db88c53 DH |
544 | req = rxkad_get_call_crypto(call); |
545 | if (!req) | |
546 | return -ENOMEM; | |
547 | ||
17926a79 DH |
548 | /* continue encrypting from where we left off */ |
549 | memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); | |
17926a79 DH |
550 | |
551 | /* validate the security checksum */ | |
01a90a45 | 552 | x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT); |
5a42976d | 553 | x |= seq & 0x3fffffff; |
a263629d HX |
554 | call->crypto_buf[0] = htonl(call->call_id); |
555 | call->crypto_buf[1] = htonl(x); | |
1afe593b | 556 | |
a263629d | 557 | sg_init_one(&sg, call->crypto_buf, 8); |
69d826fa | 558 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 559 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 560 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
561 | crypto_skcipher_encrypt(req); |
562 | skcipher_request_zero(req); | |
17926a79 | 563 | |
a263629d | 564 | y = ntohl(call->crypto_buf[1]); |
0d12f8a4 DH |
565 | cksum = (y >> 16) & 0xffff; |
566 | if (cksum == 0) | |
567 | cksum = 1; /* zero checksums are not permitted */ | |
17926a79 | 568 | |
5a42976d | 569 | if (cksum != expected_cksum) { |
fb46f6ee DH |
570 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK", |
571 | RXKADSEALEDINCON); | |
572 | goto protocol_error; | |
17926a79 DH |
573 | } |
574 | ||
19ffa01c | 575 | switch (call->conn->params.security_level) { |
17926a79 | 576 | case RXRPC_SECURITY_PLAIN: |
5a42976d | 577 | return 0; |
17926a79 | 578 | case RXRPC_SECURITY_AUTH: |
54424d38 | 579 | return rxkad_verify_packet_1(call, skb, offset, len, seq, req); |
17926a79 | 580 | case RXRPC_SECURITY_ENCRYPT: |
54424d38 | 581 | return rxkad_verify_packet_2(call, skb, offset, len, seq, req); |
17926a79 | 582 | default: |
5a42976d | 583 | return -ENOANO; |
17926a79 | 584 | } |
fb46f6ee DH |
585 | |
586 | protocol_error: | |
587 | if (aborted) | |
588 | rxrpc_send_abort_packet(call); | |
589 | return -EPROTO; | |
17926a79 DH |
590 | } |
591 | ||
248f219c DH |
592 | /* |
593 | * Locate the data contained in a packet that was partially encrypted. | |
594 | */ | |
595 | static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb, | |
596 | unsigned int *_offset, unsigned int *_len) | |
597 | { | |
598 | struct rxkad_level1_hdr sechdr; | |
599 | ||
600 | if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0) | |
601 | BUG(); | |
602 | *_offset += sizeof(sechdr); | |
603 | *_len = ntohl(sechdr.data_size) & 0xffff; | |
604 | } | |
605 | ||
606 | /* | |
607 | * Locate the data contained in a packet that was completely encrypted. | |
608 | */ | |
609 | static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb, | |
610 | unsigned int *_offset, unsigned int *_len) | |
611 | { | |
612 | struct rxkad_level2_hdr sechdr; | |
613 | ||
614 | if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0) | |
615 | BUG(); | |
616 | *_offset += sizeof(sechdr); | |
617 | *_len = ntohl(sechdr.data_size) & 0xffff; | |
618 | } | |
619 | ||
620 | /* | |
621 | * Locate the data contained in an already decrypted packet. | |
622 | */ | |
623 | static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb, | |
624 | unsigned int *_offset, unsigned int *_len) | |
625 | { | |
626 | switch (call->conn->params.security_level) { | |
627 | case RXRPC_SECURITY_AUTH: | |
628 | rxkad_locate_data_1(call, skb, _offset, _len); | |
629 | return; | |
630 | case RXRPC_SECURITY_ENCRYPT: | |
631 | rxkad_locate_data_2(call, skb, _offset, _len); | |
632 | return; | |
633 | default: | |
634 | return; | |
635 | } | |
636 | } | |
637 | ||
17926a79 DH |
638 | /* |
639 | * issue a challenge | |
640 | */ | |
641 | static int rxkad_issue_challenge(struct rxrpc_connection *conn) | |
642 | { | |
643 | struct rxkad_challenge challenge; | |
0d12f8a4 | 644 | struct rxrpc_wire_header whdr; |
17926a79 DH |
645 | struct msghdr msg; |
646 | struct kvec iov[2]; | |
647 | size_t len; | |
0d12f8a4 | 648 | u32 serial; |
17926a79 DH |
649 | int ret; |
650 | ||
19ffa01c | 651 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 652 | |
19ffa01c | 653 | ret = key_validate(conn->params.key); |
17926a79 DH |
654 | if (ret < 0) |
655 | return ret; | |
656 | ||
657 | get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce)); | |
658 | ||
659 | challenge.version = htonl(2); | |
660 | challenge.nonce = htonl(conn->security_nonce); | |
661 | challenge.min_level = htonl(0); | |
662 | challenge.__padding = 0; | |
663 | ||
7b674e39 DH |
664 | msg.msg_name = &conn->params.peer->srx.transport; |
665 | msg.msg_namelen = conn->params.peer->srx.transport_len; | |
17926a79 DH |
666 | msg.msg_control = NULL; |
667 | msg.msg_controllen = 0; | |
668 | msg.msg_flags = 0; | |
669 | ||
19ffa01c DH |
670 | whdr.epoch = htonl(conn->proto.epoch); |
671 | whdr.cid = htonl(conn->proto.cid); | |
0d12f8a4 DH |
672 | whdr.callNumber = 0; |
673 | whdr.seq = 0; | |
674 | whdr.type = RXRPC_PACKET_TYPE_CHALLENGE; | |
675 | whdr.flags = conn->out_clientflag; | |
676 | whdr.userStatus = 0; | |
677 | whdr.securityIndex = conn->security_ix; | |
678 | whdr._rsvd = 0; | |
68d6d1ae | 679 | whdr.serviceId = htons(conn->service_id); |
0d12f8a4 DH |
680 | |
681 | iov[0].iov_base = &whdr; | |
682 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
683 | iov[1].iov_base = &challenge; |
684 | iov[1].iov_len = sizeof(challenge); | |
685 | ||
686 | len = iov[0].iov_len + iov[1].iov_len; | |
687 | ||
0d12f8a4 DH |
688 | serial = atomic_inc_return(&conn->serial); |
689 | whdr.serial = htonl(serial); | |
690 | _proto("Tx CHALLENGE %%%u", serial); | |
17926a79 | 691 | |
85f32278 | 692 | ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len); |
17926a79 | 693 | if (ret < 0) { |
6b47fe1d | 694 | trace_rxrpc_tx_fail(conn->debug_id, serial, ret, |
4764c0da | 695 | rxrpc_tx_point_rxkad_challenge); |
17926a79 DH |
696 | return -EAGAIN; |
697 | } | |
698 | ||
330bdcfa | 699 | conn->params.peer->last_tx_at = ktime_get_seconds(); |
4764c0da DH |
700 | trace_rxrpc_tx_packet(conn->debug_id, &whdr, |
701 | rxrpc_tx_point_rxkad_challenge); | |
17926a79 DH |
702 | _leave(" = 0"); |
703 | return 0; | |
704 | } | |
705 | ||
706 | /* | |
707 | * send a Kerberos security response | |
708 | */ | |
709 | static int rxkad_send_response(struct rxrpc_connection *conn, | |
0d12f8a4 | 710 | struct rxrpc_host_header *hdr, |
17926a79 DH |
711 | struct rxkad_response *resp, |
712 | const struct rxkad_key *s2) | |
713 | { | |
0d12f8a4 | 714 | struct rxrpc_wire_header whdr; |
17926a79 DH |
715 | struct msghdr msg; |
716 | struct kvec iov[3]; | |
717 | size_t len; | |
0d12f8a4 | 718 | u32 serial; |
17926a79 DH |
719 | int ret; |
720 | ||
721 | _enter(""); | |
722 | ||
7b674e39 DH |
723 | msg.msg_name = &conn->params.peer->srx.transport; |
724 | msg.msg_namelen = conn->params.peer->srx.transport_len; | |
17926a79 DH |
725 | msg.msg_control = NULL; |
726 | msg.msg_controllen = 0; | |
727 | msg.msg_flags = 0; | |
728 | ||
0d12f8a4 DH |
729 | memset(&whdr, 0, sizeof(whdr)); |
730 | whdr.epoch = htonl(hdr->epoch); | |
731 | whdr.cid = htonl(hdr->cid); | |
732 | whdr.type = RXRPC_PACKET_TYPE_RESPONSE; | |
733 | whdr.flags = conn->out_clientflag; | |
734 | whdr.securityIndex = hdr->securityIndex; | |
735 | whdr.serviceId = htons(hdr->serviceId); | |
17926a79 | 736 | |
0d12f8a4 DH |
737 | iov[0].iov_base = &whdr; |
738 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
739 | iov[1].iov_base = resp; |
740 | iov[1].iov_len = sizeof(*resp); | |
0d12f8a4 | 741 | iov[2].iov_base = (void *)s2->ticket; |
17926a79 DH |
742 | iov[2].iov_len = s2->ticket_len; |
743 | ||
744 | len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len; | |
745 | ||
0d12f8a4 DH |
746 | serial = atomic_inc_return(&conn->serial); |
747 | whdr.serial = htonl(serial); | |
748 | _proto("Tx RESPONSE %%%u", serial); | |
17926a79 | 749 | |
85f32278 | 750 | ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len); |
17926a79 | 751 | if (ret < 0) { |
6b47fe1d | 752 | trace_rxrpc_tx_fail(conn->debug_id, serial, ret, |
4764c0da | 753 | rxrpc_tx_point_rxkad_response); |
17926a79 DH |
754 | return -EAGAIN; |
755 | } | |
756 | ||
330bdcfa | 757 | conn->params.peer->last_tx_at = ktime_get_seconds(); |
17926a79 DH |
758 | _leave(" = 0"); |
759 | return 0; | |
760 | } | |
761 | ||
762 | /* | |
763 | * calculate the response checksum | |
764 | */ | |
765 | static void rxkad_calc_response_checksum(struct rxkad_response *response) | |
766 | { | |
767 | u32 csum = 1000003; | |
768 | int loop; | |
769 | u8 *p = (u8 *) response; | |
770 | ||
771 | for (loop = sizeof(*response); loop > 0; loop--) | |
772 | csum = csum * 0x10204081 + *p++; | |
773 | ||
774 | response->encrypted.checksum = htonl(csum); | |
775 | } | |
776 | ||
17926a79 DH |
777 | /* |
778 | * encrypt the response packet | |
779 | */ | |
1db88c53 DH |
780 | static int rxkad_encrypt_response(struct rxrpc_connection *conn, |
781 | struct rxkad_response *resp, | |
782 | const struct rxkad_key *s2) | |
17926a79 | 783 | { |
1db88c53 | 784 | struct skcipher_request *req; |
17926a79 | 785 | struct rxrpc_crypt iv; |
a263629d | 786 | struct scatterlist sg[1]; |
17926a79 | 787 | |
1db88c53 DH |
788 | req = skcipher_request_alloc(&conn->cipher->base, GFP_NOFS); |
789 | if (!req) | |
790 | return -ENOMEM; | |
791 | ||
17926a79 DH |
792 | /* continue encrypting from where we left off */ |
793 | memcpy(&iv, s2->session_key, sizeof(iv)); | |
17926a79 | 794 | |
a263629d HX |
795 | sg_init_table(sg, 1); |
796 | sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted)); | |
69d826fa | 797 | skcipher_request_set_sync_tfm(req, conn->cipher); |
1afe593b HX |
798 | skcipher_request_set_callback(req, 0, NULL, NULL); |
799 | skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x); | |
1afe593b | 800 | crypto_skcipher_encrypt(req); |
1db88c53 DH |
801 | skcipher_request_free(req); |
802 | return 0; | |
17926a79 DH |
803 | } |
804 | ||
805 | /* | |
806 | * respond to a challenge packet | |
807 | */ | |
808 | static int rxkad_respond_to_challenge(struct rxrpc_connection *conn, | |
809 | struct sk_buff *skb, | |
810 | u32 *_abort_code) | |
811 | { | |
33941284 | 812 | const struct rxrpc_key_token *token; |
17926a79 | 813 | struct rxkad_challenge challenge; |
8c2f826d | 814 | struct rxkad_response *resp; |
248f219c | 815 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
fb46f6ee | 816 | const char *eproto; |
17926a79 DH |
817 | u32 version, nonce, min_level, abort_code; |
818 | int ret; | |
819 | ||
19ffa01c | 820 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 821 | |
fb46f6ee | 822 | eproto = tracepoint_string("chall_no_key"); |
ef68622d DH |
823 | abort_code = RX_PROTOCOL_ERROR; |
824 | if (!conn->params.key) | |
825 | goto protocol_error; | |
17926a79 | 826 | |
ef68622d | 827 | abort_code = RXKADEXPIRED; |
19ffa01c | 828 | ret = key_validate(conn->params.key); |
ef68622d DH |
829 | if (ret < 0) |
830 | goto other_error; | |
17926a79 | 831 | |
fb46f6ee | 832 | eproto = tracepoint_string("chall_short"); |
17926a79 | 833 | abort_code = RXKADPACKETSHORT; |
775e5b71 DH |
834 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
835 | &challenge, sizeof(challenge)) < 0) | |
17926a79 DH |
836 | goto protocol_error; |
837 | ||
838 | version = ntohl(challenge.version); | |
839 | nonce = ntohl(challenge.nonce); | |
840 | min_level = ntohl(challenge.min_level); | |
841 | ||
842 | _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }", | |
0d12f8a4 | 843 | sp->hdr.serial, version, nonce, min_level); |
17926a79 | 844 | |
fb46f6ee | 845 | eproto = tracepoint_string("chall_ver"); |
17926a79 DH |
846 | abort_code = RXKADINCONSISTENCY; |
847 | if (version != RXKAD_VERSION) | |
848 | goto protocol_error; | |
849 | ||
850 | abort_code = RXKADLEVELFAIL; | |
ef68622d | 851 | ret = -EACCES; |
19ffa01c | 852 | if (conn->params.security_level < min_level) |
ef68622d | 853 | goto other_error; |
17926a79 | 854 | |
19ffa01c | 855 | token = conn->params.key->payload.data[0]; |
17926a79 DH |
856 | |
857 | /* build the response packet */ | |
8c2f826d DH |
858 | resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS); |
859 | if (!resp) | |
860 | return -ENOMEM; | |
861 | ||
862 | resp->version = htonl(RXKAD_VERSION); | |
863 | resp->encrypted.epoch = htonl(conn->proto.epoch); | |
864 | resp->encrypted.cid = htonl(conn->proto.cid); | |
865 | resp->encrypted.securityIndex = htonl(conn->security_ix); | |
866 | resp->encrypted.inc_nonce = htonl(nonce + 1); | |
867 | resp->encrypted.level = htonl(conn->params.security_level); | |
868 | resp->kvno = htonl(token->kad->kvno); | |
869 | resp->ticket_len = htonl(token->kad->ticket_len); | |
870 | resp->encrypted.call_id[0] = htonl(conn->channels[0].call_counter); | |
871 | resp->encrypted.call_id[1] = htonl(conn->channels[1].call_counter); | |
872 | resp->encrypted.call_id[2] = htonl(conn->channels[2].call_counter); | |
873 | resp->encrypted.call_id[3] = htonl(conn->channels[3].call_counter); | |
17926a79 DH |
874 | |
875 | /* calculate the response checksum and then do the encryption */ | |
8c2f826d | 876 | rxkad_calc_response_checksum(resp); |
1db88c53 DH |
877 | ret = rxkad_encrypt_response(conn, resp, token->kad); |
878 | if (ret == 0) | |
879 | ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad); | |
8c2f826d DH |
880 | kfree(resp); |
881 | return ret; | |
17926a79 DH |
882 | |
883 | protocol_error: | |
fb46f6ee | 884 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
ef68622d DH |
885 | ret = -EPROTO; |
886 | other_error: | |
17926a79 | 887 | *_abort_code = abort_code; |
ef68622d | 888 | return ret; |
17926a79 DH |
889 | } |
890 | ||
891 | /* | |
892 | * decrypt the kerberos IV ticket in the response | |
893 | */ | |
894 | static int rxkad_decrypt_ticket(struct rxrpc_connection *conn, | |
fb46f6ee | 895 | struct sk_buff *skb, |
17926a79 DH |
896 | void *ticket, size_t ticket_len, |
897 | struct rxrpc_crypt *_session_key, | |
10674a03 | 898 | time64_t *_expiry, |
17926a79 DH |
899 | u32 *_abort_code) |
900 | { | |
1afe593b | 901 | struct skcipher_request *req; |
fb46f6ee | 902 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 | 903 | struct rxrpc_crypt iv, key; |
68e3f5dd | 904 | struct scatterlist sg[1]; |
17926a79 | 905 | struct in_addr addr; |
95c96174 | 906 | unsigned int life; |
fb46f6ee | 907 | const char *eproto; |
10674a03 | 908 | time64_t issue, now; |
17926a79 DH |
909 | bool little_endian; |
910 | int ret; | |
fb46f6ee | 911 | u32 abort_code; |
17926a79 DH |
912 | u8 *p, *q, *name, *end; |
913 | ||
914 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key)); | |
915 | ||
916 | *_expiry = 0; | |
917 | ||
918 | ret = key_validate(conn->server_key); | |
919 | if (ret < 0) { | |
920 | switch (ret) { | |
921 | case -EKEYEXPIRED: | |
fb46f6ee | 922 | abort_code = RXKADEXPIRED; |
ef68622d | 923 | goto other_error; |
17926a79 | 924 | default: |
fb46f6ee | 925 | abort_code = RXKADNOAUTH; |
ef68622d | 926 | goto other_error; |
17926a79 DH |
927 | } |
928 | } | |
929 | ||
146aa8b1 | 930 | ASSERT(conn->server_key->payload.data[0] != NULL); |
17926a79 DH |
931 | ASSERTCMP((unsigned long) ticket & 7UL, ==, 0); |
932 | ||
146aa8b1 | 933 | memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv)); |
17926a79 | 934 | |
ef68622d | 935 | ret = -ENOMEM; |
1afe593b HX |
936 | req = skcipher_request_alloc(conn->server_key->payload.data[0], |
937 | GFP_NOFS); | |
ef68622d DH |
938 | if (!req) |
939 | goto temporary_error; | |
17926a79 | 940 | |
68e3f5dd | 941 | sg_init_one(&sg[0], ticket, ticket_len); |
1afe593b HX |
942 | skcipher_request_set_callback(req, 0, NULL, NULL); |
943 | skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x); | |
1afe593b HX |
944 | crypto_skcipher_decrypt(req); |
945 | skcipher_request_free(req); | |
17926a79 DH |
946 | |
947 | p = ticket; | |
948 | end = p + ticket_len; | |
949 | ||
fb46f6ee | 950 | #define Z(field) \ |
17926a79 DH |
951 | ({ \ |
952 | u8 *__str = p; \ | |
fb46f6ee | 953 | eproto = tracepoint_string("rxkad_bad_"#field); \ |
17926a79 | 954 | q = memchr(p, 0, end - p); \ |
fb46f6ee | 955 | if (!q || q - p > (field##_SZ)) \ |
17926a79 DH |
956 | goto bad_ticket; \ |
957 | for (; p < q; p++) \ | |
958 | if (!isprint(*p)) \ | |
959 | goto bad_ticket; \ | |
960 | p++; \ | |
961 | __str; \ | |
962 | }) | |
963 | ||
964 | /* extract the ticket flags */ | |
965 | _debug("KIV FLAGS: %x", *p); | |
966 | little_endian = *p & 1; | |
967 | p++; | |
968 | ||
969 | /* extract the authentication name */ | |
fb46f6ee | 970 | name = Z(ANAME); |
17926a79 DH |
971 | _debug("KIV ANAME: %s", name); |
972 | ||
973 | /* extract the principal's instance */ | |
fb46f6ee | 974 | name = Z(INST); |
17926a79 DH |
975 | _debug("KIV INST : %s", name); |
976 | ||
977 | /* extract the principal's authentication domain */ | |
fb46f6ee | 978 | name = Z(REALM); |
17926a79 DH |
979 | _debug("KIV REALM: %s", name); |
980 | ||
fb46f6ee | 981 | eproto = tracepoint_string("rxkad_bad_len"); |
17926a79 DH |
982 | if (end - p < 4 + 8 + 4 + 2) |
983 | goto bad_ticket; | |
984 | ||
985 | /* get the IPv4 address of the entity that requested the ticket */ | |
986 | memcpy(&addr, p, sizeof(addr)); | |
987 | p += 4; | |
21454aaa | 988 | _debug("KIV ADDR : %pI4", &addr); |
17926a79 DH |
989 | |
990 | /* get the session key from the ticket */ | |
991 | memcpy(&key, p, sizeof(key)); | |
992 | p += 8; | |
993 | _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1])); | |
994 | memcpy(_session_key, &key, sizeof(key)); | |
995 | ||
996 | /* get the ticket's lifetime */ | |
997 | life = *p++ * 5 * 60; | |
998 | _debug("KIV LIFE : %u", life); | |
999 | ||
1000 | /* get the issue time of the ticket */ | |
1001 | if (little_endian) { | |
1002 | __le32 stamp; | |
1003 | memcpy(&stamp, p, 4); | |
10674a03 | 1004 | issue = rxrpc_u32_to_time64(le32_to_cpu(stamp)); |
17926a79 DH |
1005 | } else { |
1006 | __be32 stamp; | |
1007 | memcpy(&stamp, p, 4); | |
10674a03 | 1008 | issue = rxrpc_u32_to_time64(be32_to_cpu(stamp)); |
17926a79 DH |
1009 | } |
1010 | p += 4; | |
10674a03 BW |
1011 | now = ktime_get_real_seconds(); |
1012 | _debug("KIV ISSUE: %llx [%llx]", issue, now); | |
17926a79 DH |
1013 | |
1014 | /* check the ticket is in date */ | |
1015 | if (issue > now) { | |
fb46f6ee | 1016 | abort_code = RXKADNOAUTH; |
17926a79 | 1017 | ret = -EKEYREJECTED; |
ef68622d | 1018 | goto other_error; |
17926a79 DH |
1019 | } |
1020 | ||
1021 | if (issue < now - life) { | |
fb46f6ee | 1022 | abort_code = RXKADEXPIRED; |
17926a79 | 1023 | ret = -EKEYEXPIRED; |
ef68622d | 1024 | goto other_error; |
17926a79 DH |
1025 | } |
1026 | ||
1027 | *_expiry = issue + life; | |
1028 | ||
1029 | /* get the service name */ | |
fb46f6ee | 1030 | name = Z(SNAME); |
17926a79 DH |
1031 | _debug("KIV SNAME: %s", name); |
1032 | ||
1033 | /* get the service instance name */ | |
fb46f6ee | 1034 | name = Z(INST); |
17926a79 | 1035 | _debug("KIV SINST: %s", name); |
ef68622d | 1036 | return 0; |
17926a79 DH |
1037 | |
1038 | bad_ticket: | |
fb46f6ee DH |
1039 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
1040 | abort_code = RXKADBADTICKET; | |
ef68622d DH |
1041 | ret = -EPROTO; |
1042 | other_error: | |
fb46f6ee | 1043 | *_abort_code = abort_code; |
ef68622d DH |
1044 | return ret; |
1045 | temporary_error: | |
1046 | return ret; | |
17926a79 DH |
1047 | } |
1048 | ||
1049 | /* | |
1050 | * decrypt the response packet | |
1051 | */ | |
1052 | static void rxkad_decrypt_response(struct rxrpc_connection *conn, | |
1053 | struct rxkad_response *resp, | |
1054 | const struct rxrpc_crypt *session_key) | |
1055 | { | |
1db88c53 | 1056 | struct skcipher_request *req = rxkad_ci_req; |
a263629d | 1057 | struct scatterlist sg[1]; |
17926a79 DH |
1058 | struct rxrpc_crypt iv; |
1059 | ||
1060 | _enter(",,%08x%08x", | |
1061 | ntohl(session_key->n[0]), ntohl(session_key->n[1])); | |
1062 | ||
17926a79 | 1063 | mutex_lock(&rxkad_ci_mutex); |
69d826fa | 1064 | if (crypto_sync_skcipher_setkey(rxkad_ci, session_key->x, |
1db88c53 | 1065 | sizeof(*session_key)) < 0) |
17926a79 DH |
1066 | BUG(); |
1067 | ||
1068 | memcpy(&iv, session_key, sizeof(iv)); | |
17926a79 | 1069 | |
a263629d HX |
1070 | sg_init_table(sg, 1); |
1071 | sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted)); | |
69d826fa | 1072 | skcipher_request_set_sync_tfm(req, rxkad_ci); |
1afe593b HX |
1073 | skcipher_request_set_callback(req, 0, NULL, NULL); |
1074 | skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x); | |
1afe593b HX |
1075 | crypto_skcipher_decrypt(req); |
1076 | skcipher_request_zero(req); | |
1077 | ||
17926a79 DH |
1078 | mutex_unlock(&rxkad_ci_mutex); |
1079 | ||
1080 | _leave(""); | |
1081 | } | |
1082 | ||
1083 | /* | |
1084 | * verify a response | |
1085 | */ | |
1086 | static int rxkad_verify_response(struct rxrpc_connection *conn, | |
1087 | struct sk_buff *skb, | |
1088 | u32 *_abort_code) | |
1089 | { | |
8c2f826d | 1090 | struct rxkad_response *response; |
248f219c | 1091 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 | 1092 | struct rxrpc_crypt session_key; |
fb46f6ee | 1093 | const char *eproto; |
10674a03 | 1094 | time64_t expiry; |
17926a79 | 1095 | void *ticket; |
91e916cf AV |
1096 | u32 abort_code, version, kvno, ticket_len, level; |
1097 | __be32 csum; | |
a1399f8b | 1098 | int ret, i; |
17926a79 DH |
1099 | |
1100 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key)); | |
1101 | ||
8c2f826d DH |
1102 | ret = -ENOMEM; |
1103 | response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS); | |
1104 | if (!response) | |
1105 | goto temporary_error; | |
1106 | ||
fb46f6ee | 1107 | eproto = tracepoint_string("rxkad_rsp_short"); |
17926a79 | 1108 | abort_code = RXKADPACKETSHORT; |
775e5b71 | 1109 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
8c2f826d | 1110 | response, sizeof(*response)) < 0) |
17926a79 | 1111 | goto protocol_error; |
8c2f826d | 1112 | if (!pskb_pull(skb, sizeof(*response))) |
17926a79 DH |
1113 | BUG(); |
1114 | ||
8c2f826d DH |
1115 | version = ntohl(response->version); |
1116 | ticket_len = ntohl(response->ticket_len); | |
1117 | kvno = ntohl(response->kvno); | |
17926a79 | 1118 | _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }", |
0d12f8a4 | 1119 | sp->hdr.serial, version, kvno, ticket_len); |
17926a79 | 1120 | |
fb46f6ee | 1121 | eproto = tracepoint_string("rxkad_rsp_ver"); |
17926a79 DH |
1122 | abort_code = RXKADINCONSISTENCY; |
1123 | if (version != RXKAD_VERSION) | |
4aa9cb32 | 1124 | goto protocol_error; |
17926a79 | 1125 | |
fb46f6ee | 1126 | eproto = tracepoint_string("rxkad_rsp_tktlen"); |
17926a79 DH |
1127 | abort_code = RXKADTICKETLEN; |
1128 | if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN) | |
1129 | goto protocol_error; | |
1130 | ||
fb46f6ee | 1131 | eproto = tracepoint_string("rxkad_rsp_unkkey"); |
17926a79 DH |
1132 | abort_code = RXKADUNKNOWNKEY; |
1133 | if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5) | |
1134 | goto protocol_error; | |
1135 | ||
1136 | /* extract the kerberos ticket and decrypt and decode it */ | |
ef68622d | 1137 | ret = -ENOMEM; |
17926a79 DH |
1138 | ticket = kmalloc(ticket_len, GFP_NOFS); |
1139 | if (!ticket) | |
ef68622d | 1140 | goto temporary_error; |
17926a79 | 1141 | |
fb46f6ee | 1142 | eproto = tracepoint_string("rxkad_tkt_short"); |
17926a79 | 1143 | abort_code = RXKADPACKETSHORT; |
775e5b71 DH |
1144 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
1145 | ticket, ticket_len) < 0) | |
17926a79 DH |
1146 | goto protocol_error_free; |
1147 | ||
fb46f6ee | 1148 | ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key, |
ef68622d DH |
1149 | &expiry, _abort_code); |
1150 | if (ret < 0) | |
8c2f826d | 1151 | goto temporary_error_free_resp; |
17926a79 DH |
1152 | |
1153 | /* use the session key from inside the ticket to decrypt the | |
1154 | * response */ | |
8c2f826d | 1155 | rxkad_decrypt_response(conn, response, &session_key); |
17926a79 | 1156 | |
fb46f6ee | 1157 | eproto = tracepoint_string("rxkad_rsp_param"); |
17926a79 | 1158 | abort_code = RXKADSEALEDINCON; |
8c2f826d | 1159 | if (ntohl(response->encrypted.epoch) != conn->proto.epoch) |
17926a79 | 1160 | goto protocol_error_free; |
8c2f826d | 1161 | if (ntohl(response->encrypted.cid) != conn->proto.cid) |
17926a79 | 1162 | goto protocol_error_free; |
8c2f826d | 1163 | if (ntohl(response->encrypted.securityIndex) != conn->security_ix) |
17926a79 | 1164 | goto protocol_error_free; |
8c2f826d DH |
1165 | csum = response->encrypted.checksum; |
1166 | response->encrypted.checksum = 0; | |
1167 | rxkad_calc_response_checksum(response); | |
fb46f6ee | 1168 | eproto = tracepoint_string("rxkad_rsp_csum"); |
8c2f826d | 1169 | if (response->encrypted.checksum != csum) |
17926a79 DH |
1170 | goto protocol_error_free; |
1171 | ||
a1399f8b DH |
1172 | spin_lock(&conn->channel_lock); |
1173 | for (i = 0; i < RXRPC_MAXCALLS; i++) { | |
1174 | struct rxrpc_call *call; | |
8c2f826d | 1175 | u32 call_id = ntohl(response->encrypted.call_id[i]); |
a1399f8b | 1176 | |
fb46f6ee | 1177 | eproto = tracepoint_string("rxkad_rsp_callid"); |
a1399f8b DH |
1178 | if (call_id > INT_MAX) |
1179 | goto protocol_error_unlock; | |
1180 | ||
fb46f6ee | 1181 | eproto = tracepoint_string("rxkad_rsp_callctr"); |
a1399f8b DH |
1182 | if (call_id < conn->channels[i].call_counter) |
1183 | goto protocol_error_unlock; | |
fb46f6ee DH |
1184 | |
1185 | eproto = tracepoint_string("rxkad_rsp_callst"); | |
a1399f8b DH |
1186 | if (call_id > conn->channels[i].call_counter) { |
1187 | call = rcu_dereference_protected( | |
1188 | conn->channels[i].call, | |
1189 | lockdep_is_held(&conn->channel_lock)); | |
1190 | if (call && call->state < RXRPC_CALL_COMPLETE) | |
1191 | goto protocol_error_unlock; | |
1192 | conn->channels[i].call_counter = call_id; | |
1193 | } | |
1194 | } | |
1195 | spin_unlock(&conn->channel_lock); | |
17926a79 | 1196 | |
fb46f6ee | 1197 | eproto = tracepoint_string("rxkad_rsp_seq"); |
17926a79 | 1198 | abort_code = RXKADOUTOFSEQUENCE; |
8c2f826d | 1199 | if (ntohl(response->encrypted.inc_nonce) != conn->security_nonce + 1) |
17926a79 DH |
1200 | goto protocol_error_free; |
1201 | ||
fb46f6ee | 1202 | eproto = tracepoint_string("rxkad_rsp_level"); |
17926a79 | 1203 | abort_code = RXKADLEVELFAIL; |
8c2f826d | 1204 | level = ntohl(response->encrypted.level); |
17926a79 DH |
1205 | if (level > RXRPC_SECURITY_ENCRYPT) |
1206 | goto protocol_error_free; | |
19ffa01c | 1207 | conn->params.security_level = level; |
17926a79 DH |
1208 | |
1209 | /* create a key to hold the security data and expiration time - after | |
1210 | * this the connection security can be handled in exactly the same way | |
1211 | * as for a client connection */ | |
1212 | ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno); | |
ef68622d | 1213 | if (ret < 0) |
8c2f826d | 1214 | goto temporary_error_free_ticket; |
17926a79 DH |
1215 | |
1216 | kfree(ticket); | |
8c2f826d | 1217 | kfree(response); |
17926a79 DH |
1218 | _leave(" = 0"); |
1219 | return 0; | |
1220 | ||
a1399f8b DH |
1221 | protocol_error_unlock: |
1222 | spin_unlock(&conn->channel_lock); | |
17926a79 DH |
1223 | protocol_error_free: |
1224 | kfree(ticket); | |
1225 | protocol_error: | |
8c2f826d | 1226 | kfree(response); |
fb46f6ee | 1227 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
17926a79 | 1228 | *_abort_code = abort_code; |
17926a79 | 1229 | return -EPROTO; |
ef68622d | 1230 | |
8c2f826d | 1231 | temporary_error_free_ticket: |
ef68622d | 1232 | kfree(ticket); |
8c2f826d DH |
1233 | temporary_error_free_resp: |
1234 | kfree(response); | |
ef68622d DH |
1235 | temporary_error: |
1236 | /* Ignore the response packet if we got a temporary error such as | |
1237 | * ENOMEM. We just want to send the challenge again. Note that we | |
1238 | * also come out this way if the ticket decryption fails. | |
1239 | */ | |
1240 | return ret; | |
17926a79 DH |
1241 | } |
1242 | ||
1243 | /* | |
1244 | * clear the connection security | |
1245 | */ | |
1246 | static void rxkad_clear(struct rxrpc_connection *conn) | |
1247 | { | |
1248 | _enter(""); | |
1249 | ||
1250 | if (conn->cipher) | |
69d826fa | 1251 | crypto_free_sync_skcipher(conn->cipher); |
17926a79 DH |
1252 | } |
1253 | ||
648af7fc DH |
1254 | /* |
1255 | * Initialise the rxkad security service. | |
1256 | */ | |
1257 | static int rxkad_init(void) | |
1258 | { | |
1db88c53 DH |
1259 | struct crypto_sync_skcipher *tfm; |
1260 | struct skcipher_request *req; | |
1261 | ||
648af7fc DH |
1262 | /* pin the cipher we need so that the crypto layer doesn't invoke |
1263 | * keventd to go get it */ | |
1db88c53 DH |
1264 | tfm = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0); |
1265 | if (IS_ERR(tfm)) | |
1266 | return PTR_ERR(tfm); | |
1267 | ||
1268 | req = skcipher_request_alloc(&tfm->base, GFP_KERNEL); | |
1269 | if (!req) | |
1270 | goto nomem_tfm; | |
1271 | ||
1272 | rxkad_ci_req = req; | |
1273 | rxkad_ci = tfm; | |
1274 | return 0; | |
1275 | ||
1276 | nomem_tfm: | |
1277 | crypto_free_sync_skcipher(tfm); | |
1278 | return -ENOMEM; | |
648af7fc DH |
1279 | } |
1280 | ||
1281 | /* | |
1282 | * Clean up the rxkad security service. | |
1283 | */ | |
1284 | static void rxkad_exit(void) | |
1285 | { | |
1db88c53 DH |
1286 | crypto_free_sync_skcipher(rxkad_ci); |
1287 | skcipher_request_free(rxkad_ci_req); | |
648af7fc DH |
1288 | } |
1289 | ||
17926a79 DH |
1290 | /* |
1291 | * RxRPC Kerberos-based security | |
1292 | */ | |
648af7fc | 1293 | const struct rxrpc_security rxkad = { |
17926a79 | 1294 | .name = "rxkad", |
8b815477 | 1295 | .security_index = RXRPC_SECURITY_RXKAD, |
648af7fc DH |
1296 | .init = rxkad_init, |
1297 | .exit = rxkad_exit, | |
17926a79 DH |
1298 | .init_connection_security = rxkad_init_connection_security, |
1299 | .prime_packet_security = rxkad_prime_packet_security, | |
1300 | .secure_packet = rxkad_secure_packet, | |
1301 | .verify_packet = rxkad_verify_packet, | |
1db88c53 | 1302 | .free_call_crypto = rxkad_free_call_crypto, |
248f219c | 1303 | .locate_data = rxkad_locate_data, |
17926a79 DH |
1304 | .issue_challenge = rxkad_issue_challenge, |
1305 | .respond_to_challenge = rxkad_respond_to_challenge, | |
1306 | .verify_response = rxkad_verify_response, | |
1307 | .clear = rxkad_clear, | |
1308 | }; |