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Commit | Line | Data |
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17926a79 DH |
1 | /* Kerberos-based RxRPC security |
2 | * | |
3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
9b6d5398 JP |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
1afe593b | 14 | #include <crypto/skcipher.h> |
17926a79 DH |
15 | #include <linux/module.h> |
16 | #include <linux/net.h> | |
17 | #include <linux/skbuff.h> | |
18 | #include <linux/udp.h> | |
17926a79 DH |
19 | #include <linux/scatterlist.h> |
20 | #include <linux/ctype.h> | |
5a0e3ad6 | 21 | #include <linux/slab.h> |
17926a79 DH |
22 | #include <net/sock.h> |
23 | #include <net/af_rxrpc.h> | |
33941284 | 24 | #include <keys/rxrpc-type.h> |
17926a79 DH |
25 | #include "ar-internal.h" |
26 | ||
27 | #define RXKAD_VERSION 2 | |
28 | #define MAXKRB5TICKETLEN 1024 | |
29 | #define RXKAD_TKT_TYPE_KERBEROS_V5 256 | |
30 | #define ANAME_SZ 40 /* size of authentication name */ | |
31 | #define INST_SZ 40 /* size of principal's instance */ | |
32 | #define REALM_SZ 40 /* size of principal's auth domain */ | |
33 | #define SNAME_SZ 40 /* size of service name */ | |
34 | ||
17926a79 DH |
35 | struct rxkad_level1_hdr { |
36 | __be32 data_size; /* true data size (excluding padding) */ | |
37 | }; | |
38 | ||
39 | struct rxkad_level2_hdr { | |
40 | __be32 data_size; /* true data size (excluding padding) */ | |
41 | __be32 checksum; /* decrypted data checksum */ | |
42 | }; | |
43 | ||
17926a79 DH |
44 | /* |
45 | * this holds a pinned cipher so that keventd doesn't get called by the cipher | |
46 | * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE | |
47 | * packets | |
48 | */ | |
1afe593b | 49 | static struct crypto_skcipher *rxkad_ci; |
17926a79 DH |
50 | static DEFINE_MUTEX(rxkad_ci_mutex); |
51 | ||
52 | /* | |
53 | * initialise connection security | |
54 | */ | |
55 | static int rxkad_init_connection_security(struct rxrpc_connection *conn) | |
56 | { | |
1afe593b | 57 | struct crypto_skcipher *ci; |
33941284 | 58 | struct rxrpc_key_token *token; |
17926a79 DH |
59 | int ret; |
60 | ||
19ffa01c | 61 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 62 | |
19ffa01c | 63 | token = conn->params.key->payload.data[0]; |
33941284 | 64 | conn->security_ix = token->security_index; |
17926a79 | 65 | |
1afe593b | 66 | ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC); |
17926a79 DH |
67 | if (IS_ERR(ci)) { |
68 | _debug("no cipher"); | |
69 | ret = PTR_ERR(ci); | |
70 | goto error; | |
71 | } | |
72 | ||
1afe593b HX |
73 | if (crypto_skcipher_setkey(ci, token->kad->session_key, |
74 | sizeof(token->kad->session_key)) < 0) | |
17926a79 DH |
75 | BUG(); |
76 | ||
19ffa01c | 77 | switch (conn->params.security_level) { |
17926a79 DH |
78 | case RXRPC_SECURITY_PLAIN: |
79 | break; | |
80 | case RXRPC_SECURITY_AUTH: | |
81 | conn->size_align = 8; | |
82 | conn->security_size = sizeof(struct rxkad_level1_hdr); | |
17926a79 DH |
83 | break; |
84 | case RXRPC_SECURITY_ENCRYPT: | |
85 | conn->size_align = 8; | |
86 | conn->security_size = sizeof(struct rxkad_level2_hdr); | |
17926a79 DH |
87 | break; |
88 | default: | |
89 | ret = -EKEYREJECTED; | |
90 | goto error; | |
91 | } | |
92 | ||
93 | conn->cipher = ci; | |
94 | ret = 0; | |
95 | error: | |
96 | _leave(" = %d", ret); | |
97 | return ret; | |
98 | } | |
99 | ||
100 | /* | |
101 | * prime the encryption state with the invariant parts of a connection's | |
102 | * description | |
103 | */ | |
a263629d | 104 | static int rxkad_prime_packet_security(struct rxrpc_connection *conn) |
17926a79 | 105 | { |
33941284 | 106 | struct rxrpc_key_token *token; |
1afe593b | 107 | SKCIPHER_REQUEST_ON_STACK(req, conn->cipher); |
a263629d | 108 | struct scatterlist sg; |
17926a79 | 109 | struct rxrpc_crypt iv; |
a263629d HX |
110 | __be32 *tmpbuf; |
111 | size_t tmpsize = 4 * sizeof(__be32); | |
17926a79 DH |
112 | |
113 | _enter(""); | |
114 | ||
19ffa01c | 115 | if (!conn->params.key) |
a263629d HX |
116 | return 0; |
117 | ||
118 | tmpbuf = kmalloc(tmpsize, GFP_KERNEL); | |
119 | if (!tmpbuf) | |
120 | return -ENOMEM; | |
17926a79 | 121 | |
19ffa01c | 122 | token = conn->params.key->payload.data[0]; |
33941284 | 123 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 124 | |
a263629d HX |
125 | tmpbuf[0] = htonl(conn->proto.epoch); |
126 | tmpbuf[1] = htonl(conn->proto.cid); | |
127 | tmpbuf[2] = 0; | |
128 | tmpbuf[3] = htonl(conn->security_ix); | |
1afe593b | 129 | |
a263629d | 130 | sg_init_one(&sg, tmpbuf, tmpsize); |
1afe593b HX |
131 | skcipher_request_set_tfm(req, conn->cipher); |
132 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
a263629d | 133 | skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x); |
1afe593b HX |
134 | crypto_skcipher_encrypt(req); |
135 | skcipher_request_zero(req); | |
17926a79 | 136 | |
a263629d HX |
137 | memcpy(&conn->csum_iv, tmpbuf + 2, sizeof(conn->csum_iv)); |
138 | kfree(tmpbuf); | |
139 | _leave(" = 0"); | |
140 | return 0; | |
17926a79 DH |
141 | } |
142 | ||
143 | /* | |
144 | * partially encrypt a packet (level 1 security) | |
145 | */ | |
146 | static int rxkad_secure_packet_auth(const struct rxrpc_call *call, | |
147 | struct sk_buff *skb, | |
148 | u32 data_size, | |
149 | void *sechdr) | |
150 | { | |
fb46f6ee | 151 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
1afe593b | 152 | SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher); |
a263629d | 153 | struct rxkad_level1_hdr hdr; |
17926a79 | 154 | struct rxrpc_crypt iv; |
a263629d | 155 | struct scatterlist sg; |
17926a79 DH |
156 | u16 check; |
157 | ||
17926a79 DH |
158 | _enter(""); |
159 | ||
5a924b89 | 160 | check = sp->hdr.seq ^ call->call_id; |
0d12f8a4 | 161 | data_size |= (u32)check << 16; |
17926a79 | 162 | |
a263629d HX |
163 | hdr.data_size = htonl(data_size); |
164 | memcpy(sechdr, &hdr, sizeof(hdr)); | |
17926a79 DH |
165 | |
166 | /* start the encryption afresh */ | |
167 | memset(&iv, 0, sizeof(iv)); | |
17926a79 | 168 | |
a263629d | 169 | sg_init_one(&sg, sechdr, 8); |
1afe593b HX |
170 | skcipher_request_set_tfm(req, call->conn->cipher); |
171 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
a263629d | 172 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
173 | crypto_skcipher_encrypt(req); |
174 | skcipher_request_zero(req); | |
17926a79 | 175 | |
17926a79 DH |
176 | _leave(" = 0"); |
177 | return 0; | |
178 | } | |
179 | ||
180 | /* | |
181 | * wholly encrypt a packet (level 2 security) | |
182 | */ | |
183 | static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call, | |
b4f1342f DH |
184 | struct sk_buff *skb, |
185 | u32 data_size, | |
186 | void *sechdr) | |
17926a79 | 187 | { |
33941284 | 188 | const struct rxrpc_key_token *token; |
a263629d | 189 | struct rxkad_level2_hdr rxkhdr; |
17926a79 | 190 | struct rxrpc_skb_priv *sp; |
1afe593b | 191 | SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher); |
17926a79 DH |
192 | struct rxrpc_crypt iv; |
193 | struct scatterlist sg[16]; | |
194 | struct sk_buff *trailer; | |
95c96174 | 195 | unsigned int len; |
17926a79 DH |
196 | u16 check; |
197 | int nsg; | |
1afe593b | 198 | int err; |
17926a79 DH |
199 | |
200 | sp = rxrpc_skb(skb); | |
201 | ||
202 | _enter(""); | |
203 | ||
5a924b89 | 204 | check = sp->hdr.seq ^ call->call_id; |
17926a79 | 205 | |
0d12f8a4 | 206 | rxkhdr.data_size = htonl(data_size | (u32)check << 16); |
17926a79 | 207 | rxkhdr.checksum = 0; |
a263629d | 208 | memcpy(sechdr, &rxkhdr, sizeof(rxkhdr)); |
17926a79 DH |
209 | |
210 | /* encrypt from the session key */ | |
19ffa01c | 211 | token = call->conn->params.key->payload.data[0]; |
33941284 | 212 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 213 | |
68e3f5dd | 214 | sg_init_one(&sg[0], sechdr, sizeof(rxkhdr)); |
1afe593b HX |
215 | skcipher_request_set_tfm(req, call->conn->cipher); |
216 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
a263629d | 217 | skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x); |
1afe593b | 218 | crypto_skcipher_encrypt(req); |
17926a79 DH |
219 | |
220 | /* we want to encrypt the skbuff in-place */ | |
221 | nsg = skb_cow_data(skb, 0, &trailer); | |
1afe593b | 222 | err = -ENOMEM; |
17926a79 | 223 | if (nsg < 0 || nsg > 16) |
1afe593b | 224 | goto out; |
17926a79 DH |
225 | |
226 | len = data_size + call->conn->size_align - 1; | |
227 | len &= ~(call->conn->size_align - 1); | |
228 | ||
51c739d1 | 229 | sg_init_table(sg, nsg); |
89a5ea99 JD |
230 | err = skb_to_sgvec(skb, sg, 0, len); |
231 | if (unlikely(err < 0)) | |
232 | goto out; | |
1afe593b | 233 | skcipher_request_set_crypt(req, sg, sg, len, iv.x); |
1afe593b | 234 | crypto_skcipher_encrypt(req); |
17926a79 DH |
235 | |
236 | _leave(" = 0"); | |
1afe593b HX |
237 | err = 0; |
238 | ||
239 | out: | |
240 | skcipher_request_zero(req); | |
241 | return err; | |
17926a79 DH |
242 | } |
243 | ||
244 | /* | |
245 | * checksum an RxRPC packet header | |
246 | */ | |
a263629d | 247 | static int rxkad_secure_packet(struct rxrpc_call *call, |
b4f1342f DH |
248 | struct sk_buff *skb, |
249 | size_t data_size, | |
250 | void *sechdr) | |
17926a79 DH |
251 | { |
252 | struct rxrpc_skb_priv *sp; | |
1afe593b | 253 | SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher); |
17926a79 | 254 | struct rxrpc_crypt iv; |
a263629d | 255 | struct scatterlist sg; |
0d12f8a4 | 256 | u32 x, y; |
17926a79 DH |
257 | int ret; |
258 | ||
259 | sp = rxrpc_skb(skb); | |
260 | ||
261 | _enter("{%d{%x}},{#%u},%zu,", | |
19ffa01c DH |
262 | call->debug_id, key_serial(call->conn->params.key), |
263 | sp->hdr.seq, data_size); | |
17926a79 DH |
264 | |
265 | if (!call->conn->cipher) | |
266 | return 0; | |
267 | ||
19ffa01c | 268 | ret = key_validate(call->conn->params.key); |
17926a79 DH |
269 | if (ret < 0) |
270 | return ret; | |
271 | ||
272 | /* continue encrypting from where we left off */ | |
273 | memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); | |
17926a79 DH |
274 | |
275 | /* calculate the security checksum */ | |
01a90a45 | 276 | x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT); |
0d12f8a4 | 277 | x |= sp->hdr.seq & 0x3fffffff; |
5a924b89 | 278 | call->crypto_buf[0] = htonl(call->call_id); |
a263629d | 279 | call->crypto_buf[1] = htonl(x); |
1afe593b | 280 | |
a263629d | 281 | sg_init_one(&sg, call->crypto_buf, 8); |
1afe593b HX |
282 | skcipher_request_set_tfm(req, call->conn->cipher); |
283 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
a263629d | 284 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
285 | crypto_skcipher_encrypt(req); |
286 | skcipher_request_zero(req); | |
17926a79 | 287 | |
a263629d | 288 | y = ntohl(call->crypto_buf[1]); |
91e916cf AV |
289 | y = (y >> 16) & 0xffff; |
290 | if (y == 0) | |
291 | y = 1; /* zero checksums are not permitted */ | |
0d12f8a4 | 292 | sp->hdr.cksum = y; |
17926a79 | 293 | |
19ffa01c | 294 | switch (call->conn->params.security_level) { |
17926a79 DH |
295 | case RXRPC_SECURITY_PLAIN: |
296 | ret = 0; | |
297 | break; | |
298 | case RXRPC_SECURITY_AUTH: | |
299 | ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr); | |
300 | break; | |
301 | case RXRPC_SECURITY_ENCRYPT: | |
302 | ret = rxkad_secure_packet_encrypt(call, skb, data_size, | |
303 | sechdr); | |
304 | break; | |
305 | default: | |
306 | ret = -EPERM; | |
307 | break; | |
308 | } | |
309 | ||
91e916cf | 310 | _leave(" = %d [set %hx]", ret, y); |
17926a79 DH |
311 | return ret; |
312 | } | |
313 | ||
314 | /* | |
315 | * decrypt partial encryption on a packet (level 1 security) | |
316 | */ | |
5a42976d | 317 | static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 318 | unsigned int offset, unsigned int len, |
5a42976d | 319 | rxrpc_seq_t seq) |
17926a79 DH |
320 | { |
321 | struct rxkad_level1_hdr sechdr; | |
1afe593b | 322 | SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher); |
17926a79 | 323 | struct rxrpc_crypt iv; |
68e3f5dd | 324 | struct scatterlist sg[16]; |
17926a79 | 325 | struct sk_buff *trailer; |
fb46f6ee | 326 | bool aborted; |
17926a79 DH |
327 | u32 data_size, buf; |
328 | u16 check; | |
89a5ea99 | 329 | int nsg, ret; |
17926a79 DH |
330 | |
331 | _enter(""); | |
332 | ||
248f219c | 333 | if (len < 8) { |
fb46f6ee DH |
334 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H", |
335 | RXKADSEALEDINCON); | |
5a42976d DH |
336 | goto protocol_error; |
337 | } | |
17926a79 | 338 | |
248f219c DH |
339 | /* Decrypt the skbuff in-place. TODO: We really want to decrypt |
340 | * directly into the target buffer. | |
341 | */ | |
68e3f5dd HX |
342 | nsg = skb_cow_data(skb, 0, &trailer); |
343 | if (nsg < 0 || nsg > 16) | |
17926a79 DH |
344 | goto nomem; |
345 | ||
68e3f5dd | 346 | sg_init_table(sg, nsg); |
89a5ea99 JD |
347 | ret = skb_to_sgvec(skb, sg, offset, 8); |
348 | if (unlikely(ret < 0)) | |
349 | return ret; | |
17926a79 DH |
350 | |
351 | /* start the decryption afresh */ | |
352 | memset(&iv, 0, sizeof(iv)); | |
17926a79 | 353 | |
1afe593b HX |
354 | skcipher_request_set_tfm(req, call->conn->cipher); |
355 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
356 | skcipher_request_set_crypt(req, sg, sg, 8, iv.x); | |
1afe593b HX |
357 | crypto_skcipher_decrypt(req); |
358 | skcipher_request_zero(req); | |
17926a79 | 359 | |
5a42976d | 360 | /* Extract the decrypted packet length */ |
248f219c | 361 | if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) { |
fb46f6ee DH |
362 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1", |
363 | RXKADDATALEN); | |
5a42976d DH |
364 | goto protocol_error; |
365 | } | |
248f219c DH |
366 | offset += sizeof(sechdr); |
367 | len -= sizeof(sechdr); | |
17926a79 DH |
368 | |
369 | buf = ntohl(sechdr.data_size); | |
370 | data_size = buf & 0xffff; | |
371 | ||
372 | check = buf >> 16; | |
5a42976d | 373 | check ^= seq ^ call->call_id; |
17926a79 DH |
374 | check &= 0xffff; |
375 | if (check != 0) { | |
fb46f6ee DH |
376 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C", |
377 | RXKADSEALEDINCON); | |
17926a79 DH |
378 | goto protocol_error; |
379 | } | |
380 | ||
248f219c | 381 | if (data_size > len) { |
fb46f6ee DH |
382 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L", |
383 | RXKADDATALEN); | |
5a42976d DH |
384 | goto protocol_error; |
385 | } | |
17926a79 DH |
386 | |
387 | _leave(" = 0 [dlen=%x]", data_size); | |
388 | return 0; | |
389 | ||
17926a79 | 390 | protocol_error: |
fb46f6ee DH |
391 | if (aborted) |
392 | rxrpc_send_abort_packet(call); | |
17926a79 DH |
393 | return -EPROTO; |
394 | ||
395 | nomem: | |
396 | _leave(" = -ENOMEM"); | |
397 | return -ENOMEM; | |
398 | } | |
399 | ||
400 | /* | |
401 | * wholly decrypt a packet (level 2 security) | |
402 | */ | |
5a42976d | 403 | static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 404 | unsigned int offset, unsigned int len, |
5a42976d | 405 | rxrpc_seq_t seq) |
17926a79 | 406 | { |
33941284 | 407 | const struct rxrpc_key_token *token; |
17926a79 | 408 | struct rxkad_level2_hdr sechdr; |
1afe593b | 409 | SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher); |
17926a79 DH |
410 | struct rxrpc_crypt iv; |
411 | struct scatterlist _sg[4], *sg; | |
412 | struct sk_buff *trailer; | |
fb46f6ee | 413 | bool aborted; |
17926a79 DH |
414 | u32 data_size, buf; |
415 | u16 check; | |
89a5ea99 | 416 | int nsg, ret; |
17926a79 DH |
417 | |
418 | _enter(",{%d}", skb->len); | |
419 | ||
248f219c | 420 | if (len < 8) { |
fb46f6ee DH |
421 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H", |
422 | RXKADSEALEDINCON); | |
5a42976d DH |
423 | goto protocol_error; |
424 | } | |
17926a79 | 425 | |
248f219c DH |
426 | /* Decrypt the skbuff in-place. TODO: We really want to decrypt |
427 | * directly into the target buffer. | |
428 | */ | |
17926a79 DH |
429 | nsg = skb_cow_data(skb, 0, &trailer); |
430 | if (nsg < 0) | |
431 | goto nomem; | |
432 | ||
433 | sg = _sg; | |
434 | if (unlikely(nsg > 4)) { | |
435 | sg = kmalloc(sizeof(*sg) * nsg, GFP_NOIO); | |
436 | if (!sg) | |
437 | goto nomem; | |
438 | } | |
439 | ||
68e3f5dd | 440 | sg_init_table(sg, nsg); |
89a5ea99 JD |
441 | ret = skb_to_sgvec(skb, sg, offset, len); |
442 | if (unlikely(ret < 0)) { | |
443 | if (sg != _sg) | |
444 | kfree(sg); | |
445 | return ret; | |
446 | } | |
17926a79 DH |
447 | |
448 | /* decrypt from the session key */ | |
19ffa01c | 449 | token = call->conn->params.key->payload.data[0]; |
33941284 | 450 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 451 | |
1afe593b HX |
452 | skcipher_request_set_tfm(req, call->conn->cipher); |
453 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
248f219c | 454 | skcipher_request_set_crypt(req, sg, sg, len, iv.x); |
1afe593b HX |
455 | crypto_skcipher_decrypt(req); |
456 | skcipher_request_zero(req); | |
17926a79 DH |
457 | if (sg != _sg) |
458 | kfree(sg); | |
459 | ||
5a42976d | 460 | /* Extract the decrypted packet length */ |
248f219c | 461 | if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) { |
fb46f6ee DH |
462 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2", |
463 | RXKADDATALEN); | |
5a42976d DH |
464 | goto protocol_error; |
465 | } | |
248f219c DH |
466 | offset += sizeof(sechdr); |
467 | len -= sizeof(sechdr); | |
17926a79 DH |
468 | |
469 | buf = ntohl(sechdr.data_size); | |
470 | data_size = buf & 0xffff; | |
471 | ||
472 | check = buf >> 16; | |
5a42976d | 473 | check ^= seq ^ call->call_id; |
17926a79 DH |
474 | check &= 0xffff; |
475 | if (check != 0) { | |
fb46f6ee DH |
476 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C", |
477 | RXKADSEALEDINCON); | |
17926a79 DH |
478 | goto protocol_error; |
479 | } | |
480 | ||
248f219c | 481 | if (data_size > len) { |
fb46f6ee DH |
482 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L", |
483 | RXKADDATALEN); | |
5a42976d DH |
484 | goto protocol_error; |
485 | } | |
17926a79 DH |
486 | |
487 | _leave(" = 0 [dlen=%x]", data_size); | |
488 | return 0; | |
489 | ||
17926a79 | 490 | protocol_error: |
fb46f6ee DH |
491 | if (aborted) |
492 | rxrpc_send_abort_packet(call); | |
17926a79 DH |
493 | return -EPROTO; |
494 | ||
495 | nomem: | |
496 | _leave(" = -ENOMEM"); | |
497 | return -ENOMEM; | |
498 | } | |
499 | ||
500 | /* | |
5a42976d DH |
501 | * Verify the security on a received packet or subpacket (if part of a |
502 | * jumbo packet). | |
17926a79 | 503 | */ |
5a42976d | 504 | static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb, |
248f219c | 505 | unsigned int offset, unsigned int len, |
5a42976d | 506 | rxrpc_seq_t seq, u16 expected_cksum) |
17926a79 | 507 | { |
1afe593b | 508 | SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher); |
17926a79 | 509 | struct rxrpc_crypt iv; |
a263629d | 510 | struct scatterlist sg; |
fb46f6ee | 511 | bool aborted; |
0d12f8a4 DH |
512 | u16 cksum; |
513 | u32 x, y; | |
17926a79 DH |
514 | |
515 | _enter("{%d{%x}},{#%u}", | |
5a42976d | 516 | call->debug_id, key_serial(call->conn->params.key), seq); |
17926a79 DH |
517 | |
518 | if (!call->conn->cipher) | |
519 | return 0; | |
520 | ||
17926a79 DH |
521 | /* continue encrypting from where we left off */ |
522 | memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); | |
17926a79 DH |
523 | |
524 | /* validate the security checksum */ | |
01a90a45 | 525 | x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT); |
5a42976d | 526 | x |= seq & 0x3fffffff; |
a263629d HX |
527 | call->crypto_buf[0] = htonl(call->call_id); |
528 | call->crypto_buf[1] = htonl(x); | |
1afe593b | 529 | |
a263629d | 530 | sg_init_one(&sg, call->crypto_buf, 8); |
1afe593b HX |
531 | skcipher_request_set_tfm(req, call->conn->cipher); |
532 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
a263629d | 533 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
534 | crypto_skcipher_encrypt(req); |
535 | skcipher_request_zero(req); | |
17926a79 | 536 | |
a263629d | 537 | y = ntohl(call->crypto_buf[1]); |
0d12f8a4 DH |
538 | cksum = (y >> 16) & 0xffff; |
539 | if (cksum == 0) | |
540 | cksum = 1; /* zero checksums are not permitted */ | |
17926a79 | 541 | |
5a42976d | 542 | if (cksum != expected_cksum) { |
fb46f6ee DH |
543 | aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK", |
544 | RXKADSEALEDINCON); | |
545 | goto protocol_error; | |
17926a79 DH |
546 | } |
547 | ||
19ffa01c | 548 | switch (call->conn->params.security_level) { |
17926a79 | 549 | case RXRPC_SECURITY_PLAIN: |
5a42976d | 550 | return 0; |
17926a79 | 551 | case RXRPC_SECURITY_AUTH: |
248f219c | 552 | return rxkad_verify_packet_1(call, skb, offset, len, seq); |
17926a79 | 553 | case RXRPC_SECURITY_ENCRYPT: |
248f219c | 554 | return rxkad_verify_packet_2(call, skb, offset, len, seq); |
17926a79 | 555 | default: |
5a42976d | 556 | return -ENOANO; |
17926a79 | 557 | } |
fb46f6ee DH |
558 | |
559 | protocol_error: | |
560 | if (aborted) | |
561 | rxrpc_send_abort_packet(call); | |
562 | return -EPROTO; | |
17926a79 DH |
563 | } |
564 | ||
248f219c DH |
565 | /* |
566 | * Locate the data contained in a packet that was partially encrypted. | |
567 | */ | |
568 | static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb, | |
569 | unsigned int *_offset, unsigned int *_len) | |
570 | { | |
571 | struct rxkad_level1_hdr sechdr; | |
572 | ||
573 | if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0) | |
574 | BUG(); | |
575 | *_offset += sizeof(sechdr); | |
576 | *_len = ntohl(sechdr.data_size) & 0xffff; | |
577 | } | |
578 | ||
579 | /* | |
580 | * Locate the data contained in a packet that was completely encrypted. | |
581 | */ | |
582 | static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb, | |
583 | unsigned int *_offset, unsigned int *_len) | |
584 | { | |
585 | struct rxkad_level2_hdr sechdr; | |
586 | ||
587 | if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0) | |
588 | BUG(); | |
589 | *_offset += sizeof(sechdr); | |
590 | *_len = ntohl(sechdr.data_size) & 0xffff; | |
591 | } | |
592 | ||
593 | /* | |
594 | * Locate the data contained in an already decrypted packet. | |
595 | */ | |
596 | static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb, | |
597 | unsigned int *_offset, unsigned int *_len) | |
598 | { | |
599 | switch (call->conn->params.security_level) { | |
600 | case RXRPC_SECURITY_AUTH: | |
601 | rxkad_locate_data_1(call, skb, _offset, _len); | |
602 | return; | |
603 | case RXRPC_SECURITY_ENCRYPT: | |
604 | rxkad_locate_data_2(call, skb, _offset, _len); | |
605 | return; | |
606 | default: | |
607 | return; | |
608 | } | |
609 | } | |
610 | ||
17926a79 DH |
611 | /* |
612 | * issue a challenge | |
613 | */ | |
614 | static int rxkad_issue_challenge(struct rxrpc_connection *conn) | |
615 | { | |
616 | struct rxkad_challenge challenge; | |
0d12f8a4 | 617 | struct rxrpc_wire_header whdr; |
17926a79 DH |
618 | struct msghdr msg; |
619 | struct kvec iov[2]; | |
620 | size_t len; | |
0d12f8a4 | 621 | u32 serial; |
17926a79 DH |
622 | int ret; |
623 | ||
19ffa01c | 624 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 625 | |
19ffa01c | 626 | ret = key_validate(conn->params.key); |
17926a79 DH |
627 | if (ret < 0) |
628 | return ret; | |
629 | ||
630 | get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce)); | |
631 | ||
632 | challenge.version = htonl(2); | |
633 | challenge.nonce = htonl(conn->security_nonce); | |
634 | challenge.min_level = htonl(0); | |
635 | challenge.__padding = 0; | |
636 | ||
7b674e39 DH |
637 | msg.msg_name = &conn->params.peer->srx.transport; |
638 | msg.msg_namelen = conn->params.peer->srx.transport_len; | |
17926a79 DH |
639 | msg.msg_control = NULL; |
640 | msg.msg_controllen = 0; | |
641 | msg.msg_flags = 0; | |
642 | ||
19ffa01c DH |
643 | whdr.epoch = htonl(conn->proto.epoch); |
644 | whdr.cid = htonl(conn->proto.cid); | |
0d12f8a4 DH |
645 | whdr.callNumber = 0; |
646 | whdr.seq = 0; | |
647 | whdr.type = RXRPC_PACKET_TYPE_CHALLENGE; | |
648 | whdr.flags = conn->out_clientflag; | |
649 | whdr.userStatus = 0; | |
650 | whdr.securityIndex = conn->security_ix; | |
651 | whdr._rsvd = 0; | |
68d6d1ae | 652 | whdr.serviceId = htons(conn->service_id); |
0d12f8a4 DH |
653 | |
654 | iov[0].iov_base = &whdr; | |
655 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
656 | iov[1].iov_base = &challenge; |
657 | iov[1].iov_len = sizeof(challenge); | |
658 | ||
659 | len = iov[0].iov_len + iov[1].iov_len; | |
660 | ||
0d12f8a4 DH |
661 | serial = atomic_inc_return(&conn->serial); |
662 | whdr.serial = htonl(serial); | |
663 | _proto("Tx CHALLENGE %%%u", serial); | |
17926a79 | 664 | |
85f32278 | 665 | ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len); |
17926a79 DH |
666 | if (ret < 0) { |
667 | _debug("sendmsg failed: %d", ret); | |
668 | return -EAGAIN; | |
669 | } | |
670 | ||
671 | _leave(" = 0"); | |
672 | return 0; | |
673 | } | |
674 | ||
675 | /* | |
676 | * send a Kerberos security response | |
677 | */ | |
678 | static int rxkad_send_response(struct rxrpc_connection *conn, | |
0d12f8a4 | 679 | struct rxrpc_host_header *hdr, |
17926a79 DH |
680 | struct rxkad_response *resp, |
681 | const struct rxkad_key *s2) | |
682 | { | |
0d12f8a4 | 683 | struct rxrpc_wire_header whdr; |
17926a79 DH |
684 | struct msghdr msg; |
685 | struct kvec iov[3]; | |
686 | size_t len; | |
0d12f8a4 | 687 | u32 serial; |
17926a79 DH |
688 | int ret; |
689 | ||
690 | _enter(""); | |
691 | ||
7b674e39 DH |
692 | msg.msg_name = &conn->params.peer->srx.transport; |
693 | msg.msg_namelen = conn->params.peer->srx.transport_len; | |
17926a79 DH |
694 | msg.msg_control = NULL; |
695 | msg.msg_controllen = 0; | |
696 | msg.msg_flags = 0; | |
697 | ||
0d12f8a4 DH |
698 | memset(&whdr, 0, sizeof(whdr)); |
699 | whdr.epoch = htonl(hdr->epoch); | |
700 | whdr.cid = htonl(hdr->cid); | |
701 | whdr.type = RXRPC_PACKET_TYPE_RESPONSE; | |
702 | whdr.flags = conn->out_clientflag; | |
703 | whdr.securityIndex = hdr->securityIndex; | |
704 | whdr.serviceId = htons(hdr->serviceId); | |
17926a79 | 705 | |
0d12f8a4 DH |
706 | iov[0].iov_base = &whdr; |
707 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
708 | iov[1].iov_base = resp; |
709 | iov[1].iov_len = sizeof(*resp); | |
0d12f8a4 | 710 | iov[2].iov_base = (void *)s2->ticket; |
17926a79 DH |
711 | iov[2].iov_len = s2->ticket_len; |
712 | ||
713 | len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len; | |
714 | ||
0d12f8a4 DH |
715 | serial = atomic_inc_return(&conn->serial); |
716 | whdr.serial = htonl(serial); | |
717 | _proto("Tx RESPONSE %%%u", serial); | |
17926a79 | 718 | |
85f32278 | 719 | ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len); |
17926a79 DH |
720 | if (ret < 0) { |
721 | _debug("sendmsg failed: %d", ret); | |
722 | return -EAGAIN; | |
723 | } | |
724 | ||
725 | _leave(" = 0"); | |
726 | return 0; | |
727 | } | |
728 | ||
729 | /* | |
730 | * calculate the response checksum | |
731 | */ | |
732 | static void rxkad_calc_response_checksum(struct rxkad_response *response) | |
733 | { | |
734 | u32 csum = 1000003; | |
735 | int loop; | |
736 | u8 *p = (u8 *) response; | |
737 | ||
738 | for (loop = sizeof(*response); loop > 0; loop--) | |
739 | csum = csum * 0x10204081 + *p++; | |
740 | ||
741 | response->encrypted.checksum = htonl(csum); | |
742 | } | |
743 | ||
17926a79 DH |
744 | /* |
745 | * encrypt the response packet | |
746 | */ | |
747 | static void rxkad_encrypt_response(struct rxrpc_connection *conn, | |
748 | struct rxkad_response *resp, | |
749 | const struct rxkad_key *s2) | |
750 | { | |
1afe593b | 751 | SKCIPHER_REQUEST_ON_STACK(req, conn->cipher); |
17926a79 | 752 | struct rxrpc_crypt iv; |
a263629d | 753 | struct scatterlist sg[1]; |
17926a79 DH |
754 | |
755 | /* continue encrypting from where we left off */ | |
756 | memcpy(&iv, s2->session_key, sizeof(iv)); | |
17926a79 | 757 | |
a263629d HX |
758 | sg_init_table(sg, 1); |
759 | sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted)); | |
1afe593b HX |
760 | skcipher_request_set_tfm(req, conn->cipher); |
761 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
762 | skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x); | |
1afe593b HX |
763 | crypto_skcipher_encrypt(req); |
764 | skcipher_request_zero(req); | |
17926a79 DH |
765 | } |
766 | ||
767 | /* | |
768 | * respond to a challenge packet | |
769 | */ | |
770 | static int rxkad_respond_to_challenge(struct rxrpc_connection *conn, | |
771 | struct sk_buff *skb, | |
772 | u32 *_abort_code) | |
773 | { | |
33941284 | 774 | const struct rxrpc_key_token *token; |
17926a79 DH |
775 | struct rxkad_challenge challenge; |
776 | struct rxkad_response resp | |
777 | __attribute__((aligned(8))); /* must be aligned for crypto */ | |
248f219c | 778 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
fb46f6ee | 779 | const char *eproto; |
17926a79 DH |
780 | u32 version, nonce, min_level, abort_code; |
781 | int ret; | |
782 | ||
19ffa01c | 783 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key)); |
17926a79 | 784 | |
fb46f6ee | 785 | eproto = tracepoint_string("chall_no_key"); |
ef68622d DH |
786 | abort_code = RX_PROTOCOL_ERROR; |
787 | if (!conn->params.key) | |
788 | goto protocol_error; | |
17926a79 | 789 | |
ef68622d | 790 | abort_code = RXKADEXPIRED; |
19ffa01c | 791 | ret = key_validate(conn->params.key); |
ef68622d DH |
792 | if (ret < 0) |
793 | goto other_error; | |
17926a79 | 794 | |
fb46f6ee | 795 | eproto = tracepoint_string("chall_short"); |
17926a79 | 796 | abort_code = RXKADPACKETSHORT; |
775e5b71 DH |
797 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
798 | &challenge, sizeof(challenge)) < 0) | |
17926a79 DH |
799 | goto protocol_error; |
800 | ||
801 | version = ntohl(challenge.version); | |
802 | nonce = ntohl(challenge.nonce); | |
803 | min_level = ntohl(challenge.min_level); | |
804 | ||
805 | _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }", | |
0d12f8a4 | 806 | sp->hdr.serial, version, nonce, min_level); |
17926a79 | 807 | |
fb46f6ee | 808 | eproto = tracepoint_string("chall_ver"); |
17926a79 DH |
809 | abort_code = RXKADINCONSISTENCY; |
810 | if (version != RXKAD_VERSION) | |
811 | goto protocol_error; | |
812 | ||
813 | abort_code = RXKADLEVELFAIL; | |
ef68622d | 814 | ret = -EACCES; |
19ffa01c | 815 | if (conn->params.security_level < min_level) |
ef68622d | 816 | goto other_error; |
17926a79 | 817 | |
19ffa01c | 818 | token = conn->params.key->payload.data[0]; |
17926a79 DH |
819 | |
820 | /* build the response packet */ | |
821 | memset(&resp, 0, sizeof(resp)); | |
822 | ||
098a2099 | 823 | resp.version = htonl(RXKAD_VERSION); |
19ffa01c DH |
824 | resp.encrypted.epoch = htonl(conn->proto.epoch); |
825 | resp.encrypted.cid = htonl(conn->proto.cid); | |
098a2099 DH |
826 | resp.encrypted.securityIndex = htonl(conn->security_ix); |
827 | resp.encrypted.inc_nonce = htonl(nonce + 1); | |
19ffa01c | 828 | resp.encrypted.level = htonl(conn->params.security_level); |
098a2099 DH |
829 | resp.kvno = htonl(token->kad->kvno); |
830 | resp.ticket_len = htonl(token->kad->ticket_len); | |
831 | ||
a1399f8b DH |
832 | resp.encrypted.call_id[0] = htonl(conn->channels[0].call_counter); |
833 | resp.encrypted.call_id[1] = htonl(conn->channels[1].call_counter); | |
834 | resp.encrypted.call_id[2] = htonl(conn->channels[2].call_counter); | |
835 | resp.encrypted.call_id[3] = htonl(conn->channels[3].call_counter); | |
17926a79 DH |
836 | |
837 | /* calculate the response checksum and then do the encryption */ | |
838 | rxkad_calc_response_checksum(&resp); | |
33941284 DH |
839 | rxkad_encrypt_response(conn, &resp, token->kad); |
840 | return rxkad_send_response(conn, &sp->hdr, &resp, token->kad); | |
17926a79 DH |
841 | |
842 | protocol_error: | |
fb46f6ee | 843 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
ef68622d DH |
844 | ret = -EPROTO; |
845 | other_error: | |
17926a79 | 846 | *_abort_code = abort_code; |
ef68622d | 847 | return ret; |
17926a79 DH |
848 | } |
849 | ||
850 | /* | |
851 | * decrypt the kerberos IV ticket in the response | |
852 | */ | |
853 | static int rxkad_decrypt_ticket(struct rxrpc_connection *conn, | |
fb46f6ee | 854 | struct sk_buff *skb, |
17926a79 DH |
855 | void *ticket, size_t ticket_len, |
856 | struct rxrpc_crypt *_session_key, | |
10674a03 | 857 | time64_t *_expiry, |
17926a79 DH |
858 | u32 *_abort_code) |
859 | { | |
1afe593b | 860 | struct skcipher_request *req; |
fb46f6ee | 861 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 | 862 | struct rxrpc_crypt iv, key; |
68e3f5dd | 863 | struct scatterlist sg[1]; |
17926a79 | 864 | struct in_addr addr; |
95c96174 | 865 | unsigned int life; |
fb46f6ee | 866 | const char *eproto; |
10674a03 | 867 | time64_t issue, now; |
17926a79 DH |
868 | bool little_endian; |
869 | int ret; | |
fb46f6ee | 870 | u32 abort_code; |
17926a79 DH |
871 | u8 *p, *q, *name, *end; |
872 | ||
873 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key)); | |
874 | ||
875 | *_expiry = 0; | |
876 | ||
877 | ret = key_validate(conn->server_key); | |
878 | if (ret < 0) { | |
879 | switch (ret) { | |
880 | case -EKEYEXPIRED: | |
fb46f6ee | 881 | abort_code = RXKADEXPIRED; |
ef68622d | 882 | goto other_error; |
17926a79 | 883 | default: |
fb46f6ee | 884 | abort_code = RXKADNOAUTH; |
ef68622d | 885 | goto other_error; |
17926a79 DH |
886 | } |
887 | } | |
888 | ||
146aa8b1 | 889 | ASSERT(conn->server_key->payload.data[0] != NULL); |
17926a79 DH |
890 | ASSERTCMP((unsigned long) ticket & 7UL, ==, 0); |
891 | ||
146aa8b1 | 892 | memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv)); |
17926a79 | 893 | |
ef68622d | 894 | ret = -ENOMEM; |
1afe593b HX |
895 | req = skcipher_request_alloc(conn->server_key->payload.data[0], |
896 | GFP_NOFS); | |
ef68622d DH |
897 | if (!req) |
898 | goto temporary_error; | |
17926a79 | 899 | |
68e3f5dd | 900 | sg_init_one(&sg[0], ticket, ticket_len); |
1afe593b HX |
901 | skcipher_request_set_callback(req, 0, NULL, NULL); |
902 | skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x); | |
1afe593b HX |
903 | crypto_skcipher_decrypt(req); |
904 | skcipher_request_free(req); | |
17926a79 DH |
905 | |
906 | p = ticket; | |
907 | end = p + ticket_len; | |
908 | ||
fb46f6ee | 909 | #define Z(field) \ |
17926a79 DH |
910 | ({ \ |
911 | u8 *__str = p; \ | |
fb46f6ee | 912 | eproto = tracepoint_string("rxkad_bad_"#field); \ |
17926a79 | 913 | q = memchr(p, 0, end - p); \ |
fb46f6ee | 914 | if (!q || q - p > (field##_SZ)) \ |
17926a79 DH |
915 | goto bad_ticket; \ |
916 | for (; p < q; p++) \ | |
917 | if (!isprint(*p)) \ | |
918 | goto bad_ticket; \ | |
919 | p++; \ | |
920 | __str; \ | |
921 | }) | |
922 | ||
923 | /* extract the ticket flags */ | |
924 | _debug("KIV FLAGS: %x", *p); | |
925 | little_endian = *p & 1; | |
926 | p++; | |
927 | ||
928 | /* extract the authentication name */ | |
fb46f6ee | 929 | name = Z(ANAME); |
17926a79 DH |
930 | _debug("KIV ANAME: %s", name); |
931 | ||
932 | /* extract the principal's instance */ | |
fb46f6ee | 933 | name = Z(INST); |
17926a79 DH |
934 | _debug("KIV INST : %s", name); |
935 | ||
936 | /* extract the principal's authentication domain */ | |
fb46f6ee | 937 | name = Z(REALM); |
17926a79 DH |
938 | _debug("KIV REALM: %s", name); |
939 | ||
fb46f6ee | 940 | eproto = tracepoint_string("rxkad_bad_len"); |
17926a79 DH |
941 | if (end - p < 4 + 8 + 4 + 2) |
942 | goto bad_ticket; | |
943 | ||
944 | /* get the IPv4 address of the entity that requested the ticket */ | |
945 | memcpy(&addr, p, sizeof(addr)); | |
946 | p += 4; | |
21454aaa | 947 | _debug("KIV ADDR : %pI4", &addr); |
17926a79 DH |
948 | |
949 | /* get the session key from the ticket */ | |
950 | memcpy(&key, p, sizeof(key)); | |
951 | p += 8; | |
952 | _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1])); | |
953 | memcpy(_session_key, &key, sizeof(key)); | |
954 | ||
955 | /* get the ticket's lifetime */ | |
956 | life = *p++ * 5 * 60; | |
957 | _debug("KIV LIFE : %u", life); | |
958 | ||
959 | /* get the issue time of the ticket */ | |
960 | if (little_endian) { | |
961 | __le32 stamp; | |
962 | memcpy(&stamp, p, 4); | |
10674a03 | 963 | issue = rxrpc_u32_to_time64(le32_to_cpu(stamp)); |
17926a79 DH |
964 | } else { |
965 | __be32 stamp; | |
966 | memcpy(&stamp, p, 4); | |
10674a03 | 967 | issue = rxrpc_u32_to_time64(be32_to_cpu(stamp)); |
17926a79 DH |
968 | } |
969 | p += 4; | |
10674a03 BW |
970 | now = ktime_get_real_seconds(); |
971 | _debug("KIV ISSUE: %llx [%llx]", issue, now); | |
17926a79 DH |
972 | |
973 | /* check the ticket is in date */ | |
974 | if (issue > now) { | |
fb46f6ee | 975 | abort_code = RXKADNOAUTH; |
17926a79 | 976 | ret = -EKEYREJECTED; |
ef68622d | 977 | goto other_error; |
17926a79 DH |
978 | } |
979 | ||
980 | if (issue < now - life) { | |
fb46f6ee | 981 | abort_code = RXKADEXPIRED; |
17926a79 | 982 | ret = -EKEYEXPIRED; |
ef68622d | 983 | goto other_error; |
17926a79 DH |
984 | } |
985 | ||
986 | *_expiry = issue + life; | |
987 | ||
988 | /* get the service name */ | |
fb46f6ee | 989 | name = Z(SNAME); |
17926a79 DH |
990 | _debug("KIV SNAME: %s", name); |
991 | ||
992 | /* get the service instance name */ | |
fb46f6ee | 993 | name = Z(INST); |
17926a79 | 994 | _debug("KIV SINST: %s", name); |
ef68622d | 995 | return 0; |
17926a79 DH |
996 | |
997 | bad_ticket: | |
fb46f6ee DH |
998 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
999 | abort_code = RXKADBADTICKET; | |
ef68622d DH |
1000 | ret = -EPROTO; |
1001 | other_error: | |
fb46f6ee | 1002 | *_abort_code = abort_code; |
ef68622d DH |
1003 | return ret; |
1004 | temporary_error: | |
1005 | return ret; | |
17926a79 DH |
1006 | } |
1007 | ||
1008 | /* | |
1009 | * decrypt the response packet | |
1010 | */ | |
1011 | static void rxkad_decrypt_response(struct rxrpc_connection *conn, | |
1012 | struct rxkad_response *resp, | |
1013 | const struct rxrpc_crypt *session_key) | |
1014 | { | |
1afe593b | 1015 | SKCIPHER_REQUEST_ON_STACK(req, rxkad_ci); |
a263629d | 1016 | struct scatterlist sg[1]; |
17926a79 DH |
1017 | struct rxrpc_crypt iv; |
1018 | ||
1019 | _enter(",,%08x%08x", | |
1020 | ntohl(session_key->n[0]), ntohl(session_key->n[1])); | |
1021 | ||
1022 | ASSERT(rxkad_ci != NULL); | |
1023 | ||
1024 | mutex_lock(&rxkad_ci_mutex); | |
1afe593b HX |
1025 | if (crypto_skcipher_setkey(rxkad_ci, session_key->x, |
1026 | sizeof(*session_key)) < 0) | |
17926a79 DH |
1027 | BUG(); |
1028 | ||
1029 | memcpy(&iv, session_key, sizeof(iv)); | |
17926a79 | 1030 | |
a263629d HX |
1031 | sg_init_table(sg, 1); |
1032 | sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted)); | |
1afe593b HX |
1033 | skcipher_request_set_tfm(req, rxkad_ci); |
1034 | skcipher_request_set_callback(req, 0, NULL, NULL); | |
1035 | skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x); | |
1afe593b HX |
1036 | crypto_skcipher_decrypt(req); |
1037 | skcipher_request_zero(req); | |
1038 | ||
17926a79 DH |
1039 | mutex_unlock(&rxkad_ci_mutex); |
1040 | ||
1041 | _leave(""); | |
1042 | } | |
1043 | ||
1044 | /* | |
1045 | * verify a response | |
1046 | */ | |
1047 | static int rxkad_verify_response(struct rxrpc_connection *conn, | |
1048 | struct sk_buff *skb, | |
1049 | u32 *_abort_code) | |
1050 | { | |
1051 | struct rxkad_response response | |
1052 | __attribute__((aligned(8))); /* must be aligned for crypto */ | |
248f219c | 1053 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 | 1054 | struct rxrpc_crypt session_key; |
fb46f6ee | 1055 | const char *eproto; |
10674a03 | 1056 | time64_t expiry; |
17926a79 | 1057 | void *ticket; |
91e916cf AV |
1058 | u32 abort_code, version, kvno, ticket_len, level; |
1059 | __be32 csum; | |
a1399f8b | 1060 | int ret, i; |
17926a79 DH |
1061 | |
1062 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key)); | |
1063 | ||
fb46f6ee | 1064 | eproto = tracepoint_string("rxkad_rsp_short"); |
17926a79 | 1065 | abort_code = RXKADPACKETSHORT; |
775e5b71 DH |
1066 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
1067 | &response, sizeof(response)) < 0) | |
17926a79 DH |
1068 | goto protocol_error; |
1069 | if (!pskb_pull(skb, sizeof(response))) | |
1070 | BUG(); | |
1071 | ||
1072 | version = ntohl(response.version); | |
1073 | ticket_len = ntohl(response.ticket_len); | |
1074 | kvno = ntohl(response.kvno); | |
17926a79 | 1075 | _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }", |
0d12f8a4 | 1076 | sp->hdr.serial, version, kvno, ticket_len); |
17926a79 | 1077 | |
fb46f6ee | 1078 | eproto = tracepoint_string("rxkad_rsp_ver"); |
17926a79 DH |
1079 | abort_code = RXKADINCONSISTENCY; |
1080 | if (version != RXKAD_VERSION) | |
4aa9cb32 | 1081 | goto protocol_error; |
17926a79 | 1082 | |
fb46f6ee | 1083 | eproto = tracepoint_string("rxkad_rsp_tktlen"); |
17926a79 DH |
1084 | abort_code = RXKADTICKETLEN; |
1085 | if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN) | |
1086 | goto protocol_error; | |
1087 | ||
fb46f6ee | 1088 | eproto = tracepoint_string("rxkad_rsp_unkkey"); |
17926a79 DH |
1089 | abort_code = RXKADUNKNOWNKEY; |
1090 | if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5) | |
1091 | goto protocol_error; | |
1092 | ||
1093 | /* extract the kerberos ticket and decrypt and decode it */ | |
ef68622d | 1094 | ret = -ENOMEM; |
17926a79 DH |
1095 | ticket = kmalloc(ticket_len, GFP_NOFS); |
1096 | if (!ticket) | |
ef68622d | 1097 | goto temporary_error; |
17926a79 | 1098 | |
fb46f6ee | 1099 | eproto = tracepoint_string("rxkad_tkt_short"); |
17926a79 | 1100 | abort_code = RXKADPACKETSHORT; |
775e5b71 DH |
1101 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
1102 | ticket, ticket_len) < 0) | |
17926a79 DH |
1103 | goto protocol_error_free; |
1104 | ||
fb46f6ee | 1105 | ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key, |
ef68622d DH |
1106 | &expiry, _abort_code); |
1107 | if (ret < 0) | |
1108 | goto temporary_error_free; | |
17926a79 DH |
1109 | |
1110 | /* use the session key from inside the ticket to decrypt the | |
1111 | * response */ | |
1112 | rxkad_decrypt_response(conn, &response, &session_key); | |
1113 | ||
fb46f6ee | 1114 | eproto = tracepoint_string("rxkad_rsp_param"); |
17926a79 | 1115 | abort_code = RXKADSEALEDINCON; |
19ffa01c | 1116 | if (ntohl(response.encrypted.epoch) != conn->proto.epoch) |
17926a79 | 1117 | goto protocol_error_free; |
19ffa01c | 1118 | if (ntohl(response.encrypted.cid) != conn->proto.cid) |
17926a79 DH |
1119 | goto protocol_error_free; |
1120 | if (ntohl(response.encrypted.securityIndex) != conn->security_ix) | |
1121 | goto protocol_error_free; | |
1122 | csum = response.encrypted.checksum; | |
1123 | response.encrypted.checksum = 0; | |
1124 | rxkad_calc_response_checksum(&response); | |
fb46f6ee | 1125 | eproto = tracepoint_string("rxkad_rsp_csum"); |
17926a79 DH |
1126 | if (response.encrypted.checksum != csum) |
1127 | goto protocol_error_free; | |
1128 | ||
a1399f8b DH |
1129 | spin_lock(&conn->channel_lock); |
1130 | for (i = 0; i < RXRPC_MAXCALLS; i++) { | |
1131 | struct rxrpc_call *call; | |
1132 | u32 call_id = ntohl(response.encrypted.call_id[i]); | |
1133 | ||
fb46f6ee | 1134 | eproto = tracepoint_string("rxkad_rsp_callid"); |
a1399f8b DH |
1135 | if (call_id > INT_MAX) |
1136 | goto protocol_error_unlock; | |
1137 | ||
fb46f6ee | 1138 | eproto = tracepoint_string("rxkad_rsp_callctr"); |
a1399f8b DH |
1139 | if (call_id < conn->channels[i].call_counter) |
1140 | goto protocol_error_unlock; | |
fb46f6ee DH |
1141 | |
1142 | eproto = tracepoint_string("rxkad_rsp_callst"); | |
a1399f8b DH |
1143 | if (call_id > conn->channels[i].call_counter) { |
1144 | call = rcu_dereference_protected( | |
1145 | conn->channels[i].call, | |
1146 | lockdep_is_held(&conn->channel_lock)); | |
1147 | if (call && call->state < RXRPC_CALL_COMPLETE) | |
1148 | goto protocol_error_unlock; | |
1149 | conn->channels[i].call_counter = call_id; | |
1150 | } | |
1151 | } | |
1152 | spin_unlock(&conn->channel_lock); | |
17926a79 | 1153 | |
fb46f6ee | 1154 | eproto = tracepoint_string("rxkad_rsp_seq"); |
17926a79 | 1155 | abort_code = RXKADOUTOFSEQUENCE; |
0d12f8a4 | 1156 | if (ntohl(response.encrypted.inc_nonce) != conn->security_nonce + 1) |
17926a79 DH |
1157 | goto protocol_error_free; |
1158 | ||
fb46f6ee | 1159 | eproto = tracepoint_string("rxkad_rsp_level"); |
17926a79 DH |
1160 | abort_code = RXKADLEVELFAIL; |
1161 | level = ntohl(response.encrypted.level); | |
1162 | if (level > RXRPC_SECURITY_ENCRYPT) | |
1163 | goto protocol_error_free; | |
19ffa01c | 1164 | conn->params.security_level = level; |
17926a79 DH |
1165 | |
1166 | /* create a key to hold the security data and expiration time - after | |
1167 | * this the connection security can be handled in exactly the same way | |
1168 | * as for a client connection */ | |
1169 | ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno); | |
ef68622d DH |
1170 | if (ret < 0) |
1171 | goto temporary_error_free; | |
17926a79 DH |
1172 | |
1173 | kfree(ticket); | |
1174 | _leave(" = 0"); | |
1175 | return 0; | |
1176 | ||
a1399f8b DH |
1177 | protocol_error_unlock: |
1178 | spin_unlock(&conn->channel_lock); | |
17926a79 DH |
1179 | protocol_error_free: |
1180 | kfree(ticket); | |
1181 | protocol_error: | |
fb46f6ee | 1182 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto); |
17926a79 | 1183 | *_abort_code = abort_code; |
17926a79 | 1184 | return -EPROTO; |
ef68622d DH |
1185 | |
1186 | temporary_error_free: | |
1187 | kfree(ticket); | |
1188 | temporary_error: | |
1189 | /* Ignore the response packet if we got a temporary error such as | |
1190 | * ENOMEM. We just want to send the challenge again. Note that we | |
1191 | * also come out this way if the ticket decryption fails. | |
1192 | */ | |
1193 | return ret; | |
17926a79 DH |
1194 | } |
1195 | ||
1196 | /* | |
1197 | * clear the connection security | |
1198 | */ | |
1199 | static void rxkad_clear(struct rxrpc_connection *conn) | |
1200 | { | |
1201 | _enter(""); | |
1202 | ||
1203 | if (conn->cipher) | |
1afe593b | 1204 | crypto_free_skcipher(conn->cipher); |
17926a79 DH |
1205 | } |
1206 | ||
648af7fc DH |
1207 | /* |
1208 | * Initialise the rxkad security service. | |
1209 | */ | |
1210 | static int rxkad_init(void) | |
1211 | { | |
1212 | /* pin the cipher we need so that the crypto layer doesn't invoke | |
1213 | * keventd to go get it */ | |
1214 | rxkad_ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC); | |
fa54cc70 | 1215 | return PTR_ERR_OR_ZERO(rxkad_ci); |
648af7fc DH |
1216 | } |
1217 | ||
1218 | /* | |
1219 | * Clean up the rxkad security service. | |
1220 | */ | |
1221 | static void rxkad_exit(void) | |
1222 | { | |
1223 | if (rxkad_ci) | |
1224 | crypto_free_skcipher(rxkad_ci); | |
1225 | } | |
1226 | ||
17926a79 DH |
1227 | /* |
1228 | * RxRPC Kerberos-based security | |
1229 | */ | |
648af7fc | 1230 | const struct rxrpc_security rxkad = { |
17926a79 | 1231 | .name = "rxkad", |
8b815477 | 1232 | .security_index = RXRPC_SECURITY_RXKAD, |
648af7fc DH |
1233 | .init = rxkad_init, |
1234 | .exit = rxkad_exit, | |
17926a79 DH |
1235 | .init_connection_security = rxkad_init_connection_security, |
1236 | .prime_packet_security = rxkad_prime_packet_security, | |
1237 | .secure_packet = rxkad_secure_packet, | |
1238 | .verify_packet = rxkad_verify_packet, | |
248f219c | 1239 | .locate_data = rxkad_locate_data, |
17926a79 DH |
1240 | .issue_challenge = rxkad_issue_challenge, |
1241 | .respond_to_challenge = rxkad_respond_to_challenge, | |
1242 | .verify_response = rxkad_verify_response, | |
1243 | .clear = rxkad_clear, | |
1244 | }; |