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; |
17926a79 DH |
46 | static DEFINE_MUTEX(rxkad_ci_mutex); |
47 | ||
48 | /* | |
49 | * initialise connection security | |
50 | */ | |
51 | static int rxkad_init_connection_security(struct rxrpc_connection *conn) | |
52 | { | |
69d826fa | 53 | struct crypto_sync_skcipher *ci; |
33941284 | 54 | struct rxrpc_key_token *token; |
17926a79 DH |
55 | int ret; |
56 | ||
19ffa01c | 57 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 58 | |
19ffa01c | 59 | token = conn->params.key->payload.data[0]; |
33941284 | 60 | conn->security_ix = token->security_index; |
17926a79 | 61 | |
69d826fa | 62 | ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0); |
17926a79 DH |
63 | if (IS_ERR(ci)) { |
64 | _debug("no cipher"); | |
65 | ret = PTR_ERR(ci); | |
66 | goto error; | |
67 | } | |
68 | ||
69d826fa | 69 | if (crypto_sync_skcipher_setkey(ci, token->kad->session_key, |
1afe593b | 70 | sizeof(token->kad->session_key)) < 0) |
17926a79 DH |
71 | BUG(); |
72 | ||
19ffa01c | 73 | switch (conn->params.security_level) { |
17926a79 DH |
74 | case RXRPC_SECURITY_PLAIN: |
75 | break; | |
76 | case RXRPC_SECURITY_AUTH: | |
77 | conn->size_align = 8; | |
78 | conn->security_size = sizeof(struct rxkad_level1_hdr); | |
17926a79 DH |
79 | break; |
80 | case RXRPC_SECURITY_ENCRYPT: | |
81 | conn->size_align = 8; | |
82 | conn->security_size = sizeof(struct rxkad_level2_hdr); | |
17926a79 DH |
83 | break; |
84 | default: | |
85 | ret = -EKEYREJECTED; | |
86 | goto error; | |
87 | } | |
88 | ||
89 | conn->cipher = ci; | |
90 | ret = 0; | |
91 | error: | |
92 | _leave(" = %d", ret); | |
93 | return ret; | |
94 | } | |
95 | ||
96 | /* | |
97 | * prime the encryption state with the invariant parts of a connection's | |
98 | * description | |
99 | */ | |
a263629d | 100 | static int rxkad_prime_packet_security(struct rxrpc_connection *conn) |
17926a79 | 101 | { |
33941284 | 102 | struct rxrpc_key_token *token; |
69d826fa | 103 | SYNC_SKCIPHER_REQUEST_ON_STACK(req, conn->cipher); |
a263629d | 104 | struct scatterlist sg; |
17926a79 | 105 | struct rxrpc_crypt iv; |
a263629d HX |
106 | __be32 *tmpbuf; |
107 | size_t tmpsize = 4 * sizeof(__be32); | |
17926a79 DH |
108 | |
109 | _enter(""); | |
110 | ||
19ffa01c | 111 | if (!conn->params.key) |
a263629d HX |
112 | return 0; |
113 | ||
114 | tmpbuf = kmalloc(tmpsize, GFP_KERNEL); | |
115 | if (!tmpbuf) | |
116 | return -ENOMEM; | |
17926a79 | 117 | |
19ffa01c | 118 | token = conn->params.key->payload.data[0]; |
33941284 | 119 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 120 | |
a263629d HX |
121 | tmpbuf[0] = htonl(conn->proto.epoch); |
122 | tmpbuf[1] = htonl(conn->proto.cid); | |
123 | tmpbuf[2] = 0; | |
124 | tmpbuf[3] = htonl(conn->security_ix); | |
1afe593b | 125 | |
a263629d | 126 | sg_init_one(&sg, tmpbuf, tmpsize); |
69d826fa | 127 | skcipher_request_set_sync_tfm(req, conn->cipher); |
1afe593b | 128 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 129 | skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x); |
1afe593b HX |
130 | crypto_skcipher_encrypt(req); |
131 | skcipher_request_zero(req); | |
17926a79 | 132 | |
a263629d HX |
133 | memcpy(&conn->csum_iv, tmpbuf + 2, sizeof(conn->csum_iv)); |
134 | kfree(tmpbuf); | |
135 | _leave(" = 0"); | |
136 | return 0; | |
17926a79 DH |
137 | } |
138 | ||
139 | /* | |
140 | * partially encrypt a packet (level 1 security) | |
141 | */ | |
142 | static int rxkad_secure_packet_auth(const struct rxrpc_call *call, | |
143 | struct sk_buff *skb, | |
144 | u32 data_size, | |
54424d38 KC |
145 | void *sechdr, |
146 | struct skcipher_request *req) | |
17926a79 | 147 | { |
fb46f6ee | 148 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
a263629d | 149 | struct rxkad_level1_hdr hdr; |
17926a79 | 150 | struct rxrpc_crypt iv; |
a263629d | 151 | struct scatterlist sg; |
17926a79 DH |
152 | u16 check; |
153 | ||
17926a79 DH |
154 | _enter(""); |
155 | ||
5a924b89 | 156 | check = sp->hdr.seq ^ call->call_id; |
0d12f8a4 | 157 | data_size |= (u32)check << 16; |
17926a79 | 158 | |
a263629d HX |
159 | hdr.data_size = htonl(data_size); |
160 | memcpy(sechdr, &hdr, sizeof(hdr)); | |
17926a79 DH |
161 | |
162 | /* start the encryption afresh */ | |
163 | memset(&iv, 0, sizeof(iv)); | |
17926a79 | 164 | |
a263629d | 165 | sg_init_one(&sg, sechdr, 8); |
69d826fa | 166 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 167 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 168 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
169 | crypto_skcipher_encrypt(req); |
170 | skcipher_request_zero(req); | |
17926a79 | 171 | |
17926a79 DH |
172 | _leave(" = 0"); |
173 | return 0; | |
174 | } | |
175 | ||
176 | /* | |
177 | * wholly encrypt a packet (level 2 security) | |
178 | */ | |
179 | static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call, | |
b4f1342f DH |
180 | struct sk_buff *skb, |
181 | u32 data_size, | |
54424d38 KC |
182 | void *sechdr, |
183 | struct skcipher_request *req) | |
17926a79 | 184 | { |
33941284 | 185 | const struct rxrpc_key_token *token; |
a263629d | 186 | struct rxkad_level2_hdr rxkhdr; |
17926a79 | 187 | struct rxrpc_skb_priv *sp; |
17926a79 DH |
188 | struct rxrpc_crypt iv; |
189 | struct scatterlist sg[16]; | |
95c96174 | 190 | unsigned int len; |
17926a79 | 191 | u16 check; |
1afe593b | 192 | int err; |
17926a79 DH |
193 | |
194 | sp = rxrpc_skb(skb); | |
195 | ||
196 | _enter(""); | |
197 | ||
5a924b89 | 198 | check = sp->hdr.seq ^ call->call_id; |
17926a79 | 199 | |
0d12f8a4 | 200 | rxkhdr.data_size = htonl(data_size | (u32)check << 16); |
17926a79 | 201 | rxkhdr.checksum = 0; |
a263629d | 202 | memcpy(sechdr, &rxkhdr, sizeof(rxkhdr)); |
17926a79 DH |
203 | |
204 | /* encrypt from the session key */ | |
19ffa01c | 205 | token = call->conn->params.key->payload.data[0]; |
33941284 | 206 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 207 | |
68e3f5dd | 208 | sg_init_one(&sg[0], sechdr, sizeof(rxkhdr)); |
69d826fa | 209 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 210 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 211 | skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x); |
1afe593b | 212 | crypto_skcipher_encrypt(req); |
17926a79 DH |
213 | |
214 | /* we want to encrypt the skbuff in-place */ | |
d0d5c0cd DH |
215 | err = -EMSGSIZE; |
216 | if (skb_shinfo(skb)->nr_frags > 16) | |
1afe593b | 217 | goto out; |
17926a79 DH |
218 | |
219 | len = data_size + call->conn->size_align - 1; | |
220 | len &= ~(call->conn->size_align - 1); | |
221 | ||
d0d5c0cd | 222 | sg_init_table(sg, ARRAY_SIZE(sg)); |
89a5ea99 JD |
223 | err = skb_to_sgvec(skb, sg, 0, len); |
224 | if (unlikely(err < 0)) | |
225 | goto out; | |
1afe593b | 226 | skcipher_request_set_crypt(req, sg, sg, len, iv.x); |
1afe593b | 227 | crypto_skcipher_encrypt(req); |
17926a79 DH |
228 | |
229 | _leave(" = 0"); | |
1afe593b HX |
230 | err = 0; |
231 | ||
232 | out: | |
233 | skcipher_request_zero(req); | |
234 | return err; | |
17926a79 DH |
235 | } |
236 | ||
237 | /* | |
238 | * checksum an RxRPC packet header | |
239 | */ | |
a263629d | 240 | static int rxkad_secure_packet(struct rxrpc_call *call, |
b4f1342f DH |
241 | struct sk_buff *skb, |
242 | size_t data_size, | |
243 | void *sechdr) | |
17926a79 DH |
244 | { |
245 | struct rxrpc_skb_priv *sp; | |
69d826fa | 246 | SYNC_SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher); |
17926a79 | 247 | struct rxrpc_crypt iv; |
a263629d | 248 | struct scatterlist sg; |
0d12f8a4 | 249 | u32 x, y; |
17926a79 DH |
250 | int ret; |
251 | ||
252 | sp = rxrpc_skb(skb); | |
253 | ||
254 | _enter("{%d{%x}},{#%u},%zu,", | |
19ffa01c DH |
255 | call->debug_id, key_serial(call->conn->params.key), |
256 | sp->hdr.seq, data_size); | |
17926a79 DH |
257 | |
258 | if (!call->conn->cipher) | |
259 | return 0; | |
260 | ||
19ffa01c | 261 | ret = key_validate(call->conn->params.key); |
17926a79 DH |
262 | if (ret < 0) |
263 | return ret; | |
264 | ||
265 | /* continue encrypting from where we left off */ | |
266 | memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); | |
17926a79 DH |
267 | |
268 | /* calculate the security checksum */ | |
01a90a45 | 269 | x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT); |
0d12f8a4 | 270 | x |= sp->hdr.seq & 0x3fffffff; |
5a924b89 | 271 | call->crypto_buf[0] = htonl(call->call_id); |
a263629d | 272 | call->crypto_buf[1] = htonl(x); |
1afe593b | 273 | |
a263629d | 274 | sg_init_one(&sg, call->crypto_buf, 8); |
69d826fa | 275 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 276 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 277 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
278 | crypto_skcipher_encrypt(req); |
279 | skcipher_request_zero(req); | |
17926a79 | 280 | |
a263629d | 281 | y = ntohl(call->crypto_buf[1]); |
91e916cf AV |
282 | y = (y >> 16) & 0xffff; |
283 | if (y == 0) | |
284 | y = 1; /* zero checksums are not permitted */ | |
0d12f8a4 | 285 | sp->hdr.cksum = y; |
17926a79 | 286 | |
19ffa01c | 287 | switch (call->conn->params.security_level) { |
17926a79 DH |
288 | case RXRPC_SECURITY_PLAIN: |
289 | ret = 0; | |
290 | break; | |
291 | case RXRPC_SECURITY_AUTH: | |
54424d38 KC |
292 | ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr, |
293 | req); | |
17926a79 DH |
294 | break; |
295 | case RXRPC_SECURITY_ENCRYPT: | |
296 | ret = rxkad_secure_packet_encrypt(call, skb, data_size, | |
54424d38 | 297 | sechdr, req); |
17926a79 DH |
298 | break; |
299 | default: | |
300 | ret = -EPERM; | |
301 | break; | |
302 | } | |
303 | ||
91e916cf | 304 | _leave(" = %d [set %hx]", ret, y); |
17926a79 DH |
305 | return ret; |
306 | } | |
307 | ||
308 | /* | |
309 | * decrypt partial encryption on a packet (level 1 security) | |
310 | */ | |
5a42976d | 311 | static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 312 | unsigned int offset, unsigned int len, |
54424d38 KC |
313 | rxrpc_seq_t seq, |
314 | struct skcipher_request *req) | |
17926a79 DH |
315 | { |
316 | struct rxkad_level1_hdr sechdr; | |
17926a79 | 317 | struct rxrpc_crypt iv; |
68e3f5dd | 318 | struct scatterlist sg[16]; |
fb46f6ee | 319 | bool aborted; |
17926a79 DH |
320 | u32 data_size, buf; |
321 | u16 check; | |
d0d5c0cd | 322 | int ret; |
17926a79 DH |
323 | |
324 | _enter(""); | |
325 | ||
248f219c | 326 | if (len < 8) { |
fb46f6ee DH |
327 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H", |
328 | RXKADSEALEDINCON); | |
5a42976d DH |
329 | goto protocol_error; |
330 | } | |
17926a79 | 331 | |
248f219c DH |
332 | /* Decrypt the skbuff in-place. TODO: We really want to decrypt |
333 | * directly into the target buffer. | |
334 | */ | |
d0d5c0cd | 335 | sg_init_table(sg, ARRAY_SIZE(sg)); |
89a5ea99 JD |
336 | ret = skb_to_sgvec(skb, sg, offset, 8); |
337 | if (unlikely(ret < 0)) | |
338 | return ret; | |
17926a79 DH |
339 | |
340 | /* start the decryption afresh */ | |
341 | memset(&iv, 0, sizeof(iv)); | |
17926a79 | 342 | |
69d826fa | 343 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b HX |
344 | skcipher_request_set_callback(req, 0, NULL, NULL); |
345 | skcipher_request_set_crypt(req, sg, sg, 8, iv.x); | |
1afe593b HX |
346 | crypto_skcipher_decrypt(req); |
347 | skcipher_request_zero(req); | |
17926a79 | 348 | |
5a42976d | 349 | /* Extract the decrypted packet length */ |
248f219c | 350 | if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) { |
fb46f6ee DH |
351 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1", |
352 | RXKADDATALEN); | |
5a42976d DH |
353 | goto protocol_error; |
354 | } | |
248f219c DH |
355 | offset += sizeof(sechdr); |
356 | len -= sizeof(sechdr); | |
17926a79 DH |
357 | |
358 | buf = ntohl(sechdr.data_size); | |
359 | data_size = buf & 0xffff; | |
360 | ||
361 | check = buf >> 16; | |
5a42976d | 362 | check ^= seq ^ call->call_id; |
17926a79 DH |
363 | check &= 0xffff; |
364 | if (check != 0) { | |
fb46f6ee DH |
365 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C", |
366 | RXKADSEALEDINCON); | |
17926a79 DH |
367 | goto protocol_error; |
368 | } | |
369 | ||
248f219c | 370 | if (data_size > len) { |
fb46f6ee DH |
371 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L", |
372 | RXKADDATALEN); | |
5a42976d DH |
373 | goto protocol_error; |
374 | } | |
17926a79 DH |
375 | |
376 | _leave(" = 0 [dlen=%x]", data_size); | |
377 | return 0; | |
378 | ||
17926a79 | 379 | protocol_error: |
fb46f6ee DH |
380 | if (aborted) |
381 | rxrpc_send_abort_packet(call); | |
17926a79 | 382 | return -EPROTO; |
17926a79 DH |
383 | } |
384 | ||
385 | /* | |
386 | * wholly decrypt a packet (level 2 security) | |
387 | */ | |
5a42976d | 388 | static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 389 | unsigned int offset, unsigned int len, |
54424d38 KC |
390 | rxrpc_seq_t seq, |
391 | struct skcipher_request *req) | |
17926a79 | 392 | { |
33941284 | 393 | const struct rxrpc_key_token *token; |
17926a79 | 394 | struct rxkad_level2_hdr sechdr; |
17926a79 DH |
395 | struct rxrpc_crypt iv; |
396 | struct scatterlist _sg[4], *sg; | |
fb46f6ee | 397 | bool aborted; |
17926a79 DH |
398 | u32 data_size, buf; |
399 | u16 check; | |
89a5ea99 | 400 | int nsg, ret; |
17926a79 DH |
401 | |
402 | _enter(",{%d}", skb->len); | |
403 | ||
248f219c | 404 | if (len < 8) { |
fb46f6ee DH |
405 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H", |
406 | RXKADSEALEDINCON); | |
5a42976d DH |
407 | goto protocol_error; |
408 | } | |
17926a79 | 409 | |
248f219c DH |
410 | /* Decrypt the skbuff in-place. TODO: We really want to decrypt |
411 | * directly into the target buffer. | |
412 | */ | |
17926a79 | 413 | sg = _sg; |
d0d5c0cd DH |
414 | nsg = skb_shinfo(skb)->nr_frags; |
415 | if (nsg <= 4) { | |
416 | nsg = 4; | |
417 | } else { | |
6da2ec56 | 418 | sg = kmalloc_array(nsg, sizeof(*sg), GFP_NOIO); |
17926a79 DH |
419 | if (!sg) |
420 | goto nomem; | |
421 | } | |
422 | ||
68e3f5dd | 423 | sg_init_table(sg, nsg); |
89a5ea99 JD |
424 | ret = skb_to_sgvec(skb, sg, offset, len); |
425 | if (unlikely(ret < 0)) { | |
426 | if (sg != _sg) | |
427 | kfree(sg); | |
428 | return ret; | |
429 | } | |
17926a79 DH |
430 | |
431 | /* decrypt from the session key */ | |
19ffa01c | 432 | token = call->conn->params.key->payload.data[0]; |
33941284 | 433 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 434 | |
69d826fa | 435 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 436 | skcipher_request_set_callback(req, 0, NULL, NULL); |
248f219c | 437 | skcipher_request_set_crypt(req, sg, sg, len, iv.x); |
1afe593b HX |
438 | crypto_skcipher_decrypt(req); |
439 | skcipher_request_zero(req); | |
17926a79 DH |
440 | if (sg != _sg) |
441 | kfree(sg); | |
442 | ||
5a42976d | 443 | /* Extract the decrypted packet length */ |
248f219c | 444 | if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) { |
fb46f6ee DH |
445 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2", |
446 | RXKADDATALEN); | |
5a42976d DH |
447 | goto protocol_error; |
448 | } | |
248f219c DH |
449 | offset += sizeof(sechdr); |
450 | len -= sizeof(sechdr); | |
17926a79 DH |
451 | |
452 | buf = ntohl(sechdr.data_size); | |
453 | data_size = buf & 0xffff; | |
454 | ||
455 | check = buf >> 16; | |
5a42976d | 456 | check ^= seq ^ call->call_id; |
17926a79 DH |
457 | check &= 0xffff; |
458 | if (check != 0) { | |
fb46f6ee DH |
459 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C", |
460 | RXKADSEALEDINCON); | |
17926a79 DH |
461 | goto protocol_error; |
462 | } | |
463 | ||
248f219c | 464 | if (data_size > len) { |
fb46f6ee DH |
465 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L", |
466 | RXKADDATALEN); | |
5a42976d DH |
467 | goto protocol_error; |
468 | } | |
17926a79 DH |
469 | |
470 | _leave(" = 0 [dlen=%x]", data_size); | |
471 | return 0; | |
472 | ||
17926a79 | 473 | protocol_error: |
fb46f6ee DH |
474 | if (aborted) |
475 | rxrpc_send_abort_packet(call); | |
17926a79 DH |
476 | return -EPROTO; |
477 | ||
478 | nomem: | |
479 | _leave(" = -ENOMEM"); | |
480 | return -ENOMEM; | |
481 | } | |
482 | ||
483 | /* | |
5a42976d DH |
484 | * Verify the security on a received packet or subpacket (if part of a |
485 | * jumbo packet). | |
17926a79 | 486 | */ |
5a42976d | 487 | static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 488 | unsigned int offset, unsigned int len, |
5a42976d | 489 | rxrpc_seq_t seq, u16 expected_cksum) |
17926a79 | 490 | { |
69d826fa | 491 | SYNC_SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher); |
17926a79 | 492 | struct rxrpc_crypt iv; |
a263629d | 493 | struct scatterlist sg; |
fb46f6ee | 494 | bool aborted; |
0d12f8a4 DH |
495 | u16 cksum; |
496 | u32 x, y; | |
17926a79 DH |
497 | |
498 | _enter("{%d{%x}},{#%u}", | |
5a42976d | 499 | call->debug_id, key_serial(call->conn->params.key), seq); |
17926a79 DH |
500 | |
501 | if (!call->conn->cipher) | |
502 | return 0; | |
503 | ||
17926a79 DH |
504 | /* continue encrypting from where we left off */ |
505 | memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); | |
17926a79 DH |
506 | |
507 | /* validate the security checksum */ | |
01a90a45 | 508 | x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT); |
5a42976d | 509 | x |= seq & 0x3fffffff; |
a263629d HX |
510 | call->crypto_buf[0] = htonl(call->call_id); |
511 | call->crypto_buf[1] = htonl(x); | |
1afe593b | 512 | |
a263629d | 513 | sg_init_one(&sg, call->crypto_buf, 8); |
69d826fa | 514 | skcipher_request_set_sync_tfm(req, call->conn->cipher); |
1afe593b | 515 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 516 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
517 | crypto_skcipher_encrypt(req); |
518 | skcipher_request_zero(req); | |
17926a79 | 519 | |
a263629d | 520 | y = ntohl(call->crypto_buf[1]); |
0d12f8a4 DH |
521 | cksum = (y >> 16) & 0xffff; |
522 | if (cksum == 0) | |
523 | cksum = 1; /* zero checksums are not permitted */ | |
17926a79 | 524 | |
5a42976d | 525 | if (cksum != expected_cksum) { |
fb46f6ee DH |
526 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK", |
527 | RXKADSEALEDINCON); | |
528 | goto protocol_error; | |
17926a79 DH |
529 | } |
530 | ||
19ffa01c | 531 | switch (call->conn->params.security_level) { |
17926a79 | 532 | case RXRPC_SECURITY_PLAIN: |
5a42976d | 533 | return 0; |
17926a79 | 534 | case RXRPC_SECURITY_AUTH: |
54424d38 | 535 | return rxkad_verify_packet_1(call, skb, offset, len, seq, req); |
17926a79 | 536 | case RXRPC_SECURITY_ENCRYPT: |
54424d38 | 537 | return rxkad_verify_packet_2(call, skb, offset, len, seq, req); |
17926a79 | 538 | default: |
5a42976d | 539 | return -ENOANO; |
17926a79 | 540 | } |
fb46f6ee DH |
541 | |
542 | protocol_error: | |
543 | if (aborted) | |
544 | rxrpc_send_abort_packet(call); | |
545 | return -EPROTO; | |
17926a79 DH |
546 | } |
547 | ||
248f219c DH |
548 | /* |
549 | * Locate the data contained in a packet that was partially encrypted. | |
550 | */ | |
551 | static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb, | |
552 | unsigned int *_offset, unsigned int *_len) | |
553 | { | |
554 | struct rxkad_level1_hdr sechdr; | |
555 | ||
556 | if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0) | |
557 | BUG(); | |
558 | *_offset += sizeof(sechdr); | |
559 | *_len = ntohl(sechdr.data_size) & 0xffff; | |
560 | } | |
561 | ||
562 | /* | |
563 | * Locate the data contained in a packet that was completely encrypted. | |
564 | */ | |
565 | static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb, | |
566 | unsigned int *_offset, unsigned int *_len) | |
567 | { | |
568 | struct rxkad_level2_hdr sechdr; | |
569 | ||
570 | if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0) | |
571 | BUG(); | |
572 | *_offset += sizeof(sechdr); | |
573 | *_len = ntohl(sechdr.data_size) & 0xffff; | |
574 | } | |
575 | ||
576 | /* | |
577 | * Locate the data contained in an already decrypted packet. | |
578 | */ | |
579 | static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb, | |
580 | unsigned int *_offset, unsigned int *_len) | |
581 | { | |
582 | switch (call->conn->params.security_level) { | |
583 | case RXRPC_SECURITY_AUTH: | |
584 | rxkad_locate_data_1(call, skb, _offset, _len); | |
585 | return; | |
586 | case RXRPC_SECURITY_ENCRYPT: | |
587 | rxkad_locate_data_2(call, skb, _offset, _len); | |
588 | return; | |
589 | default: | |
590 | return; | |
591 | } | |
592 | } | |
593 | ||
17926a79 DH |
594 | /* |
595 | * issue a challenge | |
596 | */ | |
597 | static int rxkad_issue_challenge(struct rxrpc_connection *conn) | |
598 | { | |
599 | struct rxkad_challenge challenge; | |
0d12f8a4 | 600 | struct rxrpc_wire_header whdr; |
17926a79 DH |
601 | struct msghdr msg; |
602 | struct kvec iov[2]; | |
603 | size_t len; | |
0d12f8a4 | 604 | u32 serial; |
17926a79 DH |
605 | int ret; |
606 | ||
19ffa01c | 607 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 608 | |
19ffa01c | 609 | ret = key_validate(conn->params.key); |
17926a79 DH |
610 | if (ret < 0) |
611 | return ret; | |
612 | ||
613 | get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce)); | |
614 | ||
615 | challenge.version = htonl(2); | |
616 | challenge.nonce = htonl(conn->security_nonce); | |
617 | challenge.min_level = htonl(0); | |
618 | challenge.__padding = 0; | |
619 | ||
7b674e39 DH |
620 | msg.msg_name = &conn->params.peer->srx.transport; |
621 | msg.msg_namelen = conn->params.peer->srx.transport_len; | |
17926a79 DH |
622 | msg.msg_control = NULL; |
623 | msg.msg_controllen = 0; | |
624 | msg.msg_flags = 0; | |
625 | ||
19ffa01c DH |
626 | whdr.epoch = htonl(conn->proto.epoch); |
627 | whdr.cid = htonl(conn->proto.cid); | |
0d12f8a4 DH |
628 | whdr.callNumber = 0; |
629 | whdr.seq = 0; | |
630 | whdr.type = RXRPC_PACKET_TYPE_CHALLENGE; | |
631 | whdr.flags = conn->out_clientflag; | |
632 | whdr.userStatus = 0; | |
633 | whdr.securityIndex = conn->security_ix; | |
634 | whdr._rsvd = 0; | |
68d6d1ae | 635 | whdr.serviceId = htons(conn->service_id); |
0d12f8a4 DH |
636 | |
637 | iov[0].iov_base = &whdr; | |
638 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
639 | iov[1].iov_base = &challenge; |
640 | iov[1].iov_len = sizeof(challenge); | |
641 | ||
642 | len = iov[0].iov_len + iov[1].iov_len; | |
643 | ||
0d12f8a4 DH |
644 | serial = atomic_inc_return(&conn->serial); |
645 | whdr.serial = htonl(serial); | |
646 | _proto("Tx CHALLENGE %%%u", serial); | |
17926a79 | 647 | |
85f32278 | 648 | ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len); |
17926a79 | 649 | if (ret < 0) { |
6b47fe1d | 650 | trace_rxrpc_tx_fail(conn->debug_id, serial, ret, |
4764c0da | 651 | rxrpc_tx_point_rxkad_challenge); |
17926a79 DH |
652 | return -EAGAIN; |
653 | } | |
654 | ||
330bdcfa | 655 | conn->params.peer->last_tx_at = ktime_get_seconds(); |
4764c0da DH |
656 | trace_rxrpc_tx_packet(conn->debug_id, &whdr, |
657 | rxrpc_tx_point_rxkad_challenge); | |
17926a79 DH |
658 | _leave(" = 0"); |
659 | return 0; | |
660 | } | |
661 | ||
662 | /* | |
663 | * send a Kerberos security response | |
664 | */ | |
665 | static int rxkad_send_response(struct rxrpc_connection *conn, | |
0d12f8a4 | 666 | struct rxrpc_host_header *hdr, |
17926a79 DH |
667 | struct rxkad_response *resp, |
668 | const struct rxkad_key *s2) | |
669 | { | |
0d12f8a4 | 670 | struct rxrpc_wire_header whdr; |
17926a79 DH |
671 | struct msghdr msg; |
672 | struct kvec iov[3]; | |
673 | size_t len; | |
0d12f8a4 | 674 | u32 serial; |
17926a79 DH |
675 | int ret; |
676 | ||
677 | _enter(""); | |
678 | ||
7b674e39 DH |
679 | msg.msg_name = &conn->params.peer->srx.transport; |
680 | msg.msg_namelen = conn->params.peer->srx.transport_len; | |
17926a79 DH |
681 | msg.msg_control = NULL; |
682 | msg.msg_controllen = 0; | |
683 | msg.msg_flags = 0; | |
684 | ||
0d12f8a4 DH |
685 | memset(&whdr, 0, sizeof(whdr)); |
686 | whdr.epoch = htonl(hdr->epoch); | |
687 | whdr.cid = htonl(hdr->cid); | |
688 | whdr.type = RXRPC_PACKET_TYPE_RESPONSE; | |
689 | whdr.flags = conn->out_clientflag; | |
690 | whdr.securityIndex = hdr->securityIndex; | |
691 | whdr.serviceId = htons(hdr->serviceId); | |
17926a79 | 692 | |
0d12f8a4 DH |
693 | iov[0].iov_base = &whdr; |
694 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
695 | iov[1].iov_base = resp; |
696 | iov[1].iov_len = sizeof(*resp); | |
0d12f8a4 | 697 | iov[2].iov_base = (void *)s2->ticket; |
17926a79 DH |
698 | iov[2].iov_len = s2->ticket_len; |
699 | ||
700 | len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len; | |
701 | ||
0d12f8a4 DH |
702 | serial = atomic_inc_return(&conn->serial); |
703 | whdr.serial = htonl(serial); | |
704 | _proto("Tx RESPONSE %%%u", serial); | |
17926a79 | 705 | |
85f32278 | 706 | ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len); |
17926a79 | 707 | if (ret < 0) { |
6b47fe1d | 708 | trace_rxrpc_tx_fail(conn->debug_id, serial, ret, |
4764c0da | 709 | rxrpc_tx_point_rxkad_response); |
17926a79 DH |
710 | return -EAGAIN; |
711 | } | |
712 | ||
330bdcfa | 713 | conn->params.peer->last_tx_at = ktime_get_seconds(); |
17926a79 DH |
714 | _leave(" = 0"); |
715 | return 0; | |
716 | } | |
717 | ||
718 | /* | |
719 | * calculate the response checksum | |
720 | */ | |
721 | static void rxkad_calc_response_checksum(struct rxkad_response *response) | |
722 | { | |
723 | u32 csum = 1000003; | |
724 | int loop; | |
725 | u8 *p = (u8 *) response; | |
726 | ||
727 | for (loop = sizeof(*response); loop > 0; loop--) | |
728 | csum = csum * 0x10204081 + *p++; | |
729 | ||
730 | response->encrypted.checksum = htonl(csum); | |
731 | } | |
732 | ||
17926a79 DH |
733 | /* |
734 | * encrypt the response packet | |
735 | */ | |
736 | static void rxkad_encrypt_response(struct rxrpc_connection *conn, | |
737 | struct rxkad_response *resp, | |
738 | const struct rxkad_key *s2) | |
739 | { | |
69d826fa | 740 | SYNC_SKCIPHER_REQUEST_ON_STACK(req, conn->cipher); |
17926a79 | 741 | struct rxrpc_crypt iv; |
a263629d | 742 | struct scatterlist sg[1]; |
17926a79 DH |
743 | |
744 | /* continue encrypting from where we left off */ | |
745 | memcpy(&iv, s2->session_key, sizeof(iv)); | |
17926a79 | 746 | |
a263629d HX |
747 | sg_init_table(sg, 1); |
748 | sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted)); | |
69d826fa | 749 | skcipher_request_set_sync_tfm(req, conn->cipher); |
1afe593b HX |
750 | skcipher_request_set_callback(req, 0, NULL, NULL); |
751 | skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x); | |
1afe593b HX |
752 | crypto_skcipher_encrypt(req); |
753 | skcipher_request_zero(req); | |
17926a79 DH |
754 | } |
755 | ||
756 | /* | |
757 | * respond to a challenge packet | |
758 | */ | |
759 | static int rxkad_respond_to_challenge(struct rxrpc_connection *conn, | |
760 | struct sk_buff *skb, | |
761 | u32 *_abort_code) | |
762 | { | |
33941284 | 763 | const struct rxrpc_key_token *token; |
17926a79 | 764 | struct rxkad_challenge challenge; |
8c2f826d | 765 | struct rxkad_response *resp; |
248f219c | 766 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
fb46f6ee | 767 | const char *eproto; |
17926a79 DH |
768 | u32 version, nonce, min_level, abort_code; |
769 | int ret; | |
770 | ||
19ffa01c | 771 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 772 | |
fb46f6ee | 773 | eproto = tracepoint_string("chall_no_key"); |
ef68622d DH |
774 | abort_code = RX_PROTOCOL_ERROR; |
775 | if (!conn->params.key) | |
776 | goto protocol_error; | |
17926a79 | 777 | |
ef68622d | 778 | abort_code = RXKADEXPIRED; |
19ffa01c | 779 | ret = key_validate(conn->params.key); |
ef68622d DH |
780 | if (ret < 0) |
781 | goto other_error; | |
17926a79 | 782 | |
fb46f6ee | 783 | eproto = tracepoint_string("chall_short"); |
17926a79 | 784 | abort_code = RXKADPACKETSHORT; |
775e5b71 DH |
785 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
786 | &challenge, sizeof(challenge)) < 0) | |
17926a79 DH |
787 | goto protocol_error; |
788 | ||
789 | version = ntohl(challenge.version); | |
790 | nonce = ntohl(challenge.nonce); | |
791 | min_level = ntohl(challenge.min_level); | |
792 | ||
793 | _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }", | |
0d12f8a4 | 794 | sp->hdr.serial, version, nonce, min_level); |
17926a79 | 795 | |
fb46f6ee | 796 | eproto = tracepoint_string("chall_ver"); |
17926a79 DH |
797 | abort_code = RXKADINCONSISTENCY; |
798 | if (version != RXKAD_VERSION) | |
799 | goto protocol_error; | |
800 | ||
801 | abort_code = RXKADLEVELFAIL; | |
ef68622d | 802 | ret = -EACCES; |
19ffa01c | 803 | if (conn->params.security_level < min_level) |
ef68622d | 804 | goto other_error; |
17926a79 | 805 | |
19ffa01c | 806 | token = conn->params.key->payload.data[0]; |
17926a79 DH |
807 | |
808 | /* build the response packet */ | |
8c2f826d DH |
809 | resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS); |
810 | if (!resp) | |
811 | return -ENOMEM; | |
812 | ||
813 | resp->version = htonl(RXKAD_VERSION); | |
814 | resp->encrypted.epoch = htonl(conn->proto.epoch); | |
815 | resp->encrypted.cid = htonl(conn->proto.cid); | |
816 | resp->encrypted.securityIndex = htonl(conn->security_ix); | |
817 | resp->encrypted.inc_nonce = htonl(nonce + 1); | |
818 | resp->encrypted.level = htonl(conn->params.security_level); | |
819 | resp->kvno = htonl(token->kad->kvno); | |
820 | resp->ticket_len = htonl(token->kad->ticket_len); | |
821 | resp->encrypted.call_id[0] = htonl(conn->channels[0].call_counter); | |
822 | resp->encrypted.call_id[1] = htonl(conn->channels[1].call_counter); | |
823 | resp->encrypted.call_id[2] = htonl(conn->channels[2].call_counter); | |
824 | resp->encrypted.call_id[3] = htonl(conn->channels[3].call_counter); | |
17926a79 DH |
825 | |
826 | /* calculate the response checksum and then do the encryption */ | |
8c2f826d DH |
827 | rxkad_calc_response_checksum(resp); |
828 | rxkad_encrypt_response(conn, resp, token->kad); | |
829 | ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad); | |
830 | kfree(resp); | |
831 | return ret; | |
17926a79 DH |
832 | |
833 | protocol_error: | |
fb46f6ee | 834 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
ef68622d DH |
835 | ret = -EPROTO; |
836 | other_error: | |
17926a79 | 837 | *_abort_code = abort_code; |
ef68622d | 838 | return ret; |
17926a79 DH |
839 | } |
840 | ||
841 | /* | |
842 | * decrypt the kerberos IV ticket in the response | |
843 | */ | |
844 | static int rxkad_decrypt_ticket(struct rxrpc_connection *conn, | |
fb46f6ee | 845 | struct sk_buff *skb, |
17926a79 DH |
846 | void *ticket, size_t ticket_len, |
847 | struct rxrpc_crypt *_session_key, | |
10674a03 | 848 | time64_t *_expiry, |
17926a79 DH |
849 | u32 *_abort_code) |
850 | { | |
1afe593b | 851 | struct skcipher_request *req; |
fb46f6ee | 852 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 | 853 | struct rxrpc_crypt iv, key; |
68e3f5dd | 854 | struct scatterlist sg[1]; |
17926a79 | 855 | struct in_addr addr; |
95c96174 | 856 | unsigned int life; |
fb46f6ee | 857 | const char *eproto; |
10674a03 | 858 | time64_t issue, now; |
17926a79 DH |
859 | bool little_endian; |
860 | int ret; | |
fb46f6ee | 861 | u32 abort_code; |
17926a79 DH |
862 | u8 *p, *q, *name, *end; |
863 | ||
864 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key)); | |
865 | ||
866 | *_expiry = 0; | |
867 | ||
868 | ret = key_validate(conn->server_key); | |
869 | if (ret < 0) { | |
870 | switch (ret) { | |
871 | case -EKEYEXPIRED: | |
fb46f6ee | 872 | abort_code = RXKADEXPIRED; |
ef68622d | 873 | goto other_error; |
17926a79 | 874 | default: |
fb46f6ee | 875 | abort_code = RXKADNOAUTH; |
ef68622d | 876 | goto other_error; |
17926a79 DH |
877 | } |
878 | } | |
879 | ||
146aa8b1 | 880 | ASSERT(conn->server_key->payload.data[0] != NULL); |
17926a79 DH |
881 | ASSERTCMP((unsigned long) ticket & 7UL, ==, 0); |
882 | ||
146aa8b1 | 883 | memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv)); |
17926a79 | 884 | |
ef68622d | 885 | ret = -ENOMEM; |
1afe593b HX |
886 | req = skcipher_request_alloc(conn->server_key->payload.data[0], |
887 | GFP_NOFS); | |
ef68622d DH |
888 | if (!req) |
889 | goto temporary_error; | |
17926a79 | 890 | |
68e3f5dd | 891 | sg_init_one(&sg[0], ticket, ticket_len); |
1afe593b HX |
892 | skcipher_request_set_callback(req, 0, NULL, NULL); |
893 | skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x); | |
1afe593b HX |
894 | crypto_skcipher_decrypt(req); |
895 | skcipher_request_free(req); | |
17926a79 DH |
896 | |
897 | p = ticket; | |
898 | end = p + ticket_len; | |
899 | ||
fb46f6ee | 900 | #define Z(field) \ |
17926a79 DH |
901 | ({ \ |
902 | u8 *__str = p; \ | |
fb46f6ee | 903 | eproto = tracepoint_string("rxkad_bad_"#field); \ |
17926a79 | 904 | q = memchr(p, 0, end - p); \ |
fb46f6ee | 905 | if (!q || q - p > (field##_SZ)) \ |
17926a79 DH |
906 | goto bad_ticket; \ |
907 | for (; p < q; p++) \ | |
908 | if (!isprint(*p)) \ | |
909 | goto bad_ticket; \ | |
910 | p++; \ | |
911 | __str; \ | |
912 | }) | |
913 | ||
914 | /* extract the ticket flags */ | |
915 | _debug("KIV FLAGS: %x", *p); | |
916 | little_endian = *p & 1; | |
917 | p++; | |
918 | ||
919 | /* extract the authentication name */ | |
fb46f6ee | 920 | name = Z(ANAME); |
17926a79 DH |
921 | _debug("KIV ANAME: %s", name); |
922 | ||
923 | /* extract the principal's instance */ | |
fb46f6ee | 924 | name = Z(INST); |
17926a79 DH |
925 | _debug("KIV INST : %s", name); |
926 | ||
927 | /* extract the principal's authentication domain */ | |
fb46f6ee | 928 | name = Z(REALM); |
17926a79 DH |
929 | _debug("KIV REALM: %s", name); |
930 | ||
fb46f6ee | 931 | eproto = tracepoint_string("rxkad_bad_len"); |
17926a79 DH |
932 | if (end - p < 4 + 8 + 4 + 2) |
933 | goto bad_ticket; | |
934 | ||
935 | /* get the IPv4 address of the entity that requested the ticket */ | |
936 | memcpy(&addr, p, sizeof(addr)); | |
937 | p += 4; | |
21454aaa | 938 | _debug("KIV ADDR : %pI4", &addr); |
17926a79 DH |
939 | |
940 | /* get the session key from the ticket */ | |
941 | memcpy(&key, p, sizeof(key)); | |
942 | p += 8; | |
943 | _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1])); | |
944 | memcpy(_session_key, &key, sizeof(key)); | |
945 | ||
946 | /* get the ticket's lifetime */ | |
947 | life = *p++ * 5 * 60; | |
948 | _debug("KIV LIFE : %u", life); | |
949 | ||
950 | /* get the issue time of the ticket */ | |
951 | if (little_endian) { | |
952 | __le32 stamp; | |
953 | memcpy(&stamp, p, 4); | |
10674a03 | 954 | issue = rxrpc_u32_to_time64(le32_to_cpu(stamp)); |
17926a79 DH |
955 | } else { |
956 | __be32 stamp; | |
957 | memcpy(&stamp, p, 4); | |
10674a03 | 958 | issue = rxrpc_u32_to_time64(be32_to_cpu(stamp)); |
17926a79 DH |
959 | } |
960 | p += 4; | |
10674a03 BW |
961 | now = ktime_get_real_seconds(); |
962 | _debug("KIV ISSUE: %llx [%llx]", issue, now); | |
17926a79 DH |
963 | |
964 | /* check the ticket is in date */ | |
965 | if (issue > now) { | |
fb46f6ee | 966 | abort_code = RXKADNOAUTH; |
17926a79 | 967 | ret = -EKEYREJECTED; |
ef68622d | 968 | goto other_error; |
17926a79 DH |
969 | } |
970 | ||
971 | if (issue < now - life) { | |
fb46f6ee | 972 | abort_code = RXKADEXPIRED; |
17926a79 | 973 | ret = -EKEYEXPIRED; |
ef68622d | 974 | goto other_error; |
17926a79 DH |
975 | } |
976 | ||
977 | *_expiry = issue + life; | |
978 | ||
979 | /* get the service name */ | |
fb46f6ee | 980 | name = Z(SNAME); |
17926a79 DH |
981 | _debug("KIV SNAME: %s", name); |
982 | ||
983 | /* get the service instance name */ | |
fb46f6ee | 984 | name = Z(INST); |
17926a79 | 985 | _debug("KIV SINST: %s", name); |
ef68622d | 986 | return 0; |
17926a79 DH |
987 | |
988 | bad_ticket: | |
fb46f6ee DH |
989 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
990 | abort_code = RXKADBADTICKET; | |
ef68622d DH |
991 | ret = -EPROTO; |
992 | other_error: | |
fb46f6ee | 993 | *_abort_code = abort_code; |
ef68622d DH |
994 | return ret; |
995 | temporary_error: | |
996 | return ret; | |
17926a79 DH |
997 | } |
998 | ||
999 | /* | |
1000 | * decrypt the response packet | |
1001 | */ | |
1002 | static void rxkad_decrypt_response(struct rxrpc_connection *conn, | |
1003 | struct rxkad_response *resp, | |
1004 | const struct rxrpc_crypt *session_key) | |
1005 | { | |
69d826fa | 1006 | SYNC_SKCIPHER_REQUEST_ON_STACK(req, rxkad_ci); |
a263629d | 1007 | struct scatterlist sg[1]; |
17926a79 DH |
1008 | struct rxrpc_crypt iv; |
1009 | ||
1010 | _enter(",,%08x%08x", | |
1011 | ntohl(session_key->n[0]), ntohl(session_key->n[1])); | |
1012 | ||
1013 | ASSERT(rxkad_ci != NULL); | |
1014 | ||
1015 | mutex_lock(&rxkad_ci_mutex); | |
69d826fa | 1016 | if (crypto_sync_skcipher_setkey(rxkad_ci, session_key->x, |
1afe593b | 1017 | sizeof(*session_key)) < 0) |
17926a79 DH |
1018 | BUG(); |
1019 | ||
1020 | memcpy(&iv, session_key, sizeof(iv)); | |
17926a79 | 1021 | |
a263629d HX |
1022 | sg_init_table(sg, 1); |
1023 | sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted)); | |
69d826fa | 1024 | skcipher_request_set_sync_tfm(req, rxkad_ci); |
1afe593b HX |
1025 | skcipher_request_set_callback(req, 0, NULL, NULL); |
1026 | skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x); | |
1afe593b HX |
1027 | crypto_skcipher_decrypt(req); |
1028 | skcipher_request_zero(req); | |
1029 | ||
17926a79 DH |
1030 | mutex_unlock(&rxkad_ci_mutex); |
1031 | ||
1032 | _leave(""); | |
1033 | } | |
1034 | ||
1035 | /* | |
1036 | * verify a response | |
1037 | */ | |
1038 | static int rxkad_verify_response(struct rxrpc_connection *conn, | |
1039 | struct sk_buff *skb, | |
1040 | u32 *_abort_code) | |
1041 | { | |
8c2f826d | 1042 | struct rxkad_response *response; |
248f219c | 1043 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 | 1044 | struct rxrpc_crypt session_key; |
fb46f6ee | 1045 | const char *eproto; |
10674a03 | 1046 | time64_t expiry; |
17926a79 | 1047 | void *ticket; |
91e916cf AV |
1048 | u32 abort_code, version, kvno, ticket_len, level; |
1049 | __be32 csum; | |
a1399f8b | 1050 | int ret, i; |
17926a79 DH |
1051 | |
1052 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key)); | |
1053 | ||
8c2f826d DH |
1054 | ret = -ENOMEM; |
1055 | response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS); | |
1056 | if (!response) | |
1057 | goto temporary_error; | |
1058 | ||
fb46f6ee | 1059 | eproto = tracepoint_string("rxkad_rsp_short"); |
17926a79 | 1060 | abort_code = RXKADPACKETSHORT; |
775e5b71 | 1061 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
8c2f826d | 1062 | response, sizeof(*response)) < 0) |
17926a79 | 1063 | goto protocol_error; |
8c2f826d | 1064 | if (!pskb_pull(skb, sizeof(*response))) |
17926a79 DH |
1065 | BUG(); |
1066 | ||
8c2f826d DH |
1067 | version = ntohl(response->version); |
1068 | ticket_len = ntohl(response->ticket_len); | |
1069 | kvno = ntohl(response->kvno); | |
17926a79 | 1070 | _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }", |
0d12f8a4 | 1071 | sp->hdr.serial, version, kvno, ticket_len); |
17926a79 | 1072 | |
fb46f6ee | 1073 | eproto = tracepoint_string("rxkad_rsp_ver"); |
17926a79 DH |
1074 | abort_code = RXKADINCONSISTENCY; |
1075 | if (version != RXKAD_VERSION) | |
4aa9cb32 | 1076 | goto protocol_error; |
17926a79 | 1077 | |
fb46f6ee | 1078 | eproto = tracepoint_string("rxkad_rsp_tktlen"); |
17926a79 DH |
1079 | abort_code = RXKADTICKETLEN; |
1080 | if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN) | |
1081 | goto protocol_error; | |
1082 | ||
fb46f6ee | 1083 | eproto = tracepoint_string("rxkad_rsp_unkkey"); |
17926a79 DH |
1084 | abort_code = RXKADUNKNOWNKEY; |
1085 | if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5) | |
1086 | goto protocol_error; | |
1087 | ||
1088 | /* extract the kerberos ticket and decrypt and decode it */ | |
ef68622d | 1089 | ret = -ENOMEM; |
17926a79 DH |
1090 | ticket = kmalloc(ticket_len, GFP_NOFS); |
1091 | if (!ticket) | |
ef68622d | 1092 | goto temporary_error; |
17926a79 | 1093 | |
fb46f6ee | 1094 | eproto = tracepoint_string("rxkad_tkt_short"); |
17926a79 | 1095 | abort_code = RXKADPACKETSHORT; |
775e5b71 DH |
1096 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
1097 | ticket, ticket_len) < 0) | |
17926a79 DH |
1098 | goto protocol_error_free; |
1099 | ||
fb46f6ee | 1100 | ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key, |
ef68622d DH |
1101 | &expiry, _abort_code); |
1102 | if (ret < 0) | |
8c2f826d | 1103 | goto temporary_error_free_resp; |
17926a79 DH |
1104 | |
1105 | /* use the session key from inside the ticket to decrypt the | |
1106 | * response */ | |
8c2f826d | 1107 | rxkad_decrypt_response(conn, response, &session_key); |
17926a79 | 1108 | |
fb46f6ee | 1109 | eproto = tracepoint_string("rxkad_rsp_param"); |
17926a79 | 1110 | abort_code = RXKADSEALEDINCON; |
8c2f826d | 1111 | if (ntohl(response->encrypted.epoch) != conn->proto.epoch) |
17926a79 | 1112 | goto protocol_error_free; |
8c2f826d | 1113 | if (ntohl(response->encrypted.cid) != conn->proto.cid) |
17926a79 | 1114 | goto protocol_error_free; |
8c2f826d | 1115 | if (ntohl(response->encrypted.securityIndex) != conn->security_ix) |
17926a79 | 1116 | goto protocol_error_free; |
8c2f826d DH |
1117 | csum = response->encrypted.checksum; |
1118 | response->encrypted.checksum = 0; | |
1119 | rxkad_calc_response_checksum(response); | |
fb46f6ee | 1120 | eproto = tracepoint_string("rxkad_rsp_csum"); |
8c2f826d | 1121 | if (response->encrypted.checksum != csum) |
17926a79 DH |
1122 | goto protocol_error_free; |
1123 | ||
a1399f8b DH |
1124 | spin_lock(&conn->channel_lock); |
1125 | for (i = 0; i < RXRPC_MAXCALLS; i++) { | |
1126 | struct rxrpc_call *call; | |
8c2f826d | 1127 | u32 call_id = ntohl(response->encrypted.call_id[i]); |
a1399f8b | 1128 | |
fb46f6ee | 1129 | eproto = tracepoint_string("rxkad_rsp_callid"); |
a1399f8b DH |
1130 | if (call_id > INT_MAX) |
1131 | goto protocol_error_unlock; | |
1132 | ||
fb46f6ee | 1133 | eproto = tracepoint_string("rxkad_rsp_callctr"); |
a1399f8b DH |
1134 | if (call_id < conn->channels[i].call_counter) |
1135 | goto protocol_error_unlock; | |
fb46f6ee DH |
1136 | |
1137 | eproto = tracepoint_string("rxkad_rsp_callst"); | |
a1399f8b DH |
1138 | if (call_id > conn->channels[i].call_counter) { |
1139 | call = rcu_dereference_protected( | |
1140 | conn->channels[i].call, | |
1141 | lockdep_is_held(&conn->channel_lock)); | |
1142 | if (call && call->state < RXRPC_CALL_COMPLETE) | |
1143 | goto protocol_error_unlock; | |
1144 | conn->channels[i].call_counter = call_id; | |
1145 | } | |
1146 | } | |
1147 | spin_unlock(&conn->channel_lock); | |
17926a79 | 1148 | |
fb46f6ee | 1149 | eproto = tracepoint_string("rxkad_rsp_seq"); |
17926a79 | 1150 | abort_code = RXKADOUTOFSEQUENCE; |
8c2f826d | 1151 | if (ntohl(response->encrypted.inc_nonce) != conn->security_nonce + 1) |
17926a79 DH |
1152 | goto protocol_error_free; |
1153 | ||
fb46f6ee | 1154 | eproto = tracepoint_string("rxkad_rsp_level"); |
17926a79 | 1155 | abort_code = RXKADLEVELFAIL; |
8c2f826d | 1156 | level = ntohl(response->encrypted.level); |
17926a79 DH |
1157 | if (level > RXRPC_SECURITY_ENCRYPT) |
1158 | goto protocol_error_free; | |
19ffa01c | 1159 | conn->params.security_level = level; |
17926a79 DH |
1160 | |
1161 | /* create a key to hold the security data and expiration time - after | |
1162 | * this the connection security can be handled in exactly the same way | |
1163 | * as for a client connection */ | |
1164 | ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno); | |
ef68622d | 1165 | if (ret < 0) |
8c2f826d | 1166 | goto temporary_error_free_ticket; |
17926a79 DH |
1167 | |
1168 | kfree(ticket); | |
8c2f826d | 1169 | kfree(response); |
17926a79 DH |
1170 | _leave(" = 0"); |
1171 | return 0; | |
1172 | ||
a1399f8b DH |
1173 | protocol_error_unlock: |
1174 | spin_unlock(&conn->channel_lock); | |
17926a79 DH |
1175 | protocol_error_free: |
1176 | kfree(ticket); | |
1177 | protocol_error: | |
8c2f826d | 1178 | kfree(response); |
fb46f6ee | 1179 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
17926a79 | 1180 | *_abort_code = abort_code; |
17926a79 | 1181 | return -EPROTO; |
ef68622d | 1182 | |
8c2f826d | 1183 | temporary_error_free_ticket: |
ef68622d | 1184 | kfree(ticket); |
8c2f826d DH |
1185 | temporary_error_free_resp: |
1186 | kfree(response); | |
ef68622d DH |
1187 | temporary_error: |
1188 | /* Ignore the response packet if we got a temporary error such as | |
1189 | * ENOMEM. We just want to send the challenge again. Note that we | |
1190 | * also come out this way if the ticket decryption fails. | |
1191 | */ | |
1192 | return ret; | |
17926a79 DH |
1193 | } |
1194 | ||
1195 | /* | |
1196 | * clear the connection security | |
1197 | */ | |
1198 | static void rxkad_clear(struct rxrpc_connection *conn) | |
1199 | { | |
1200 | _enter(""); | |
1201 | ||
1202 | if (conn->cipher) | |
69d826fa | 1203 | crypto_free_sync_skcipher(conn->cipher); |
17926a79 DH |
1204 | } |
1205 | ||
648af7fc DH |
1206 | /* |
1207 | * Initialise the rxkad security service. | |
1208 | */ | |
1209 | static int rxkad_init(void) | |
1210 | { | |
1211 | /* pin the cipher we need so that the crypto layer doesn't invoke | |
1212 | * keventd to go get it */ | |
69d826fa | 1213 | rxkad_ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0); |
fa54cc70 | 1214 | return PTR_ERR_OR_ZERO(rxkad_ci); |
648af7fc DH |
1215 | } |
1216 | ||
1217 | /* | |
1218 | * Clean up the rxkad security service. | |
1219 | */ | |
1220 | static void rxkad_exit(void) | |
1221 | { | |
1222 | if (rxkad_ci) | |
69d826fa | 1223 | crypto_free_sync_skcipher(rxkad_ci); |
648af7fc DH |
1224 | } |
1225 | ||
17926a79 DH |
1226 | /* |
1227 | * RxRPC Kerberos-based security | |
1228 | */ | |
648af7fc | 1229 | const struct rxrpc_security rxkad = { |
17926a79 | 1230 | .name = "rxkad", |
8b815477 | 1231 | .security_index = RXRPC_SECURITY_RXKAD, |
648af7fc DH |
1232 | .init = rxkad_init, |
1233 | .exit = rxkad_exit, | |
17926a79 DH |
1234 | .init_connection_security = rxkad_init_connection_security, |
1235 | .prime_packet_security = rxkad_prime_packet_security, | |
1236 | .secure_packet = rxkad_secure_packet, | |
1237 | .verify_packet = rxkad_verify_packet, | |
248f219c | 1238 | .locate_data = rxkad_locate_data, |
17926a79 DH |
1239 | .issue_challenge = rxkad_issue_challenge, |
1240 | .respond_to_challenge = rxkad_respond_to_challenge, | |
1241 | .verify_response = rxkad_verify_response, | |
1242 | .clear = rxkad_clear, | |
1243 | }; |