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> |
12da59fc | 18 | #include <linux/key-type.h> |
17926a79 DH |
19 | #include <net/sock.h> |
20 | #include <net/af_rxrpc.h> | |
33941284 | 21 | #include <keys/rxrpc-type.h> |
17926a79 DH |
22 | #include "ar-internal.h" |
23 | ||
24 | #define RXKAD_VERSION 2 | |
25 | #define MAXKRB5TICKETLEN 1024 | |
26 | #define RXKAD_TKT_TYPE_KERBEROS_V5 256 | |
27 | #define ANAME_SZ 40 /* size of authentication name */ | |
28 | #define INST_SZ 40 /* size of principal's instance */ | |
29 | #define REALM_SZ 40 /* size of principal's auth domain */ | |
30 | #define SNAME_SZ 40 /* size of service name */ | |
d7d775b1 | 31 | #define RXKAD_ALIGN 8 |
17926a79 | 32 | |
17926a79 DH |
33 | struct rxkad_level1_hdr { |
34 | __be32 data_size; /* true data size (excluding padding) */ | |
35 | }; | |
36 | ||
37 | struct rxkad_level2_hdr { | |
38 | __be32 data_size; /* true data size (excluding padding) */ | |
39 | __be32 checksum; /* decrypted data checksum */ | |
40 | }; | |
41 | ||
8d47a43c DH |
42 | static int rxkad_prime_packet_security(struct rxrpc_connection *conn, |
43 | struct crypto_sync_skcipher *ci); | |
44 | ||
17926a79 DH |
45 | /* |
46 | * this holds a pinned cipher so that keventd doesn't get called by the cipher | |
47 | * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE | |
48 | * packets | |
49 | */ | |
69d826fa | 50 | static struct crypto_sync_skcipher *rxkad_ci; |
1db88c53 | 51 | static struct skcipher_request *rxkad_ci_req; |
17926a79 DH |
52 | static DEFINE_MUTEX(rxkad_ci_mutex); |
53 | ||
12da59fc DH |
54 | /* |
55 | * Parse the information from a server key | |
56 | * | |
57 | * The data should be the 8-byte secret key. | |
58 | */ | |
59 | static int rxkad_preparse_server_key(struct key_preparsed_payload *prep) | |
60 | { | |
61 | struct crypto_skcipher *ci; | |
62 | ||
63 | if (prep->datalen != 8) | |
64 | return -EINVAL; | |
65 | ||
66 | memcpy(&prep->payload.data[2], prep->data, 8); | |
67 | ||
68 | ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC); | |
69 | if (IS_ERR(ci)) { | |
70 | _leave(" = %ld", PTR_ERR(ci)); | |
71 | return PTR_ERR(ci); | |
72 | } | |
73 | ||
74 | if (crypto_skcipher_setkey(ci, prep->data, 8) < 0) | |
75 | BUG(); | |
76 | ||
77 | prep->payload.data[0] = ci; | |
78 | _leave(" = 0"); | |
79 | return 0; | |
80 | } | |
81 | ||
82 | static void rxkad_free_preparse_server_key(struct key_preparsed_payload *prep) | |
83 | { | |
d7d775b1 | 84 | |
12da59fc DH |
85 | if (prep->payload.data[0]) |
86 | crypto_free_skcipher(prep->payload.data[0]); | |
87 | } | |
88 | ||
89 | static void rxkad_destroy_server_key(struct key *key) | |
90 | { | |
91 | if (key->payload.data[0]) { | |
92 | crypto_free_skcipher(key->payload.data[0]); | |
93 | key->payload.data[0] = NULL; | |
94 | } | |
95 | } | |
96 | ||
17926a79 DH |
97 | /* |
98 | * initialise connection security | |
99 | */ | |
41057ebd DH |
100 | static int rxkad_init_connection_security(struct rxrpc_connection *conn, |
101 | struct rxrpc_key_token *token) | |
17926a79 | 102 | { |
69d826fa | 103 | struct crypto_sync_skcipher *ci; |
17926a79 DH |
104 | int ret; |
105 | ||
2cc80086 | 106 | _enter("{%d},{%x}", conn->debug_id, key_serial(conn->key)); |
17926a79 | 107 | |
33941284 | 108 | conn->security_ix = token->security_index; |
17926a79 | 109 | |
69d826fa | 110 | ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0); |
17926a79 DH |
111 | if (IS_ERR(ci)) { |
112 | _debug("no cipher"); | |
113 | ret = PTR_ERR(ci); | |
114 | goto error; | |
115 | } | |
116 | ||
69d826fa | 117 | if (crypto_sync_skcipher_setkey(ci, token->kad->session_key, |
1afe593b | 118 | sizeof(token->kad->session_key)) < 0) |
17926a79 DH |
119 | BUG(); |
120 | ||
2cc80086 | 121 | switch (conn->security_level) { |
17926a79 | 122 | case RXRPC_SECURITY_PLAIN: |
17926a79 | 123 | case RXRPC_SECURITY_AUTH: |
17926a79 | 124 | case RXRPC_SECURITY_ENCRYPT: |
17926a79 DH |
125 | break; |
126 | default: | |
127 | ret = -EKEYREJECTED; | |
128 | goto error; | |
129 | } | |
130 | ||
8d47a43c DH |
131 | ret = rxkad_prime_packet_security(conn, ci); |
132 | if (ret < 0) | |
133 | goto error_ci; | |
134 | ||
521bb304 | 135 | conn->rxkad.cipher = ci; |
8d47a43c DH |
136 | return 0; |
137 | ||
138 | error_ci: | |
139 | crypto_free_sync_skcipher(ci); | |
17926a79 DH |
140 | error: |
141 | _leave(" = %d", ret); | |
142 | return ret; | |
143 | } | |
144 | ||
d7d775b1 DH |
145 | /* |
146 | * Work out how much data we can put in a packet. | |
147 | */ | |
148 | static int rxkad_how_much_data(struct rxrpc_call *call, size_t remain, | |
149 | size_t *_buf_size, size_t *_data_size, size_t *_offset) | |
150 | { | |
151 | size_t shdr, buf_size, chunk; | |
152 | ||
2cc80086 | 153 | switch (call->conn->security_level) { |
d7d775b1 DH |
154 | default: |
155 | buf_size = chunk = min_t(size_t, remain, RXRPC_JUMBO_DATALEN); | |
156 | shdr = 0; | |
157 | goto out; | |
158 | case RXRPC_SECURITY_AUTH: | |
159 | shdr = sizeof(struct rxkad_level1_hdr); | |
160 | break; | |
161 | case RXRPC_SECURITY_ENCRYPT: | |
162 | shdr = sizeof(struct rxkad_level2_hdr); | |
163 | break; | |
164 | } | |
165 | ||
166 | buf_size = round_down(RXRPC_JUMBO_DATALEN, RXKAD_ALIGN); | |
167 | ||
168 | chunk = buf_size - shdr; | |
169 | if (remain < chunk) | |
170 | buf_size = round_up(shdr + remain, RXKAD_ALIGN); | |
171 | ||
172 | out: | |
173 | *_buf_size = buf_size; | |
174 | *_data_size = chunk; | |
175 | *_offset = shdr; | |
176 | return 0; | |
177 | } | |
178 | ||
17926a79 DH |
179 | /* |
180 | * prime the encryption state with the invariant parts of a connection's | |
181 | * description | |
182 | */ | |
8d47a43c DH |
183 | static int rxkad_prime_packet_security(struct rxrpc_connection *conn, |
184 | struct crypto_sync_skcipher *ci) | |
17926a79 | 185 | { |
1db88c53 | 186 | struct skcipher_request *req; |
33941284 | 187 | struct rxrpc_key_token *token; |
a263629d | 188 | struct scatterlist sg; |
17926a79 | 189 | struct rxrpc_crypt iv; |
a263629d HX |
190 | __be32 *tmpbuf; |
191 | size_t tmpsize = 4 * sizeof(__be32); | |
17926a79 DH |
192 | |
193 | _enter(""); | |
194 | ||
2cc80086 | 195 | if (!conn->key) |
a263629d HX |
196 | return 0; |
197 | ||
198 | tmpbuf = kmalloc(tmpsize, GFP_KERNEL); | |
199 | if (!tmpbuf) | |
200 | return -ENOMEM; | |
17926a79 | 201 | |
8d47a43c | 202 | req = skcipher_request_alloc(&ci->base, GFP_NOFS); |
1db88c53 DH |
203 | if (!req) { |
204 | kfree(tmpbuf); | |
205 | return -ENOMEM; | |
206 | } | |
207 | ||
2cc80086 | 208 | token = conn->key->payload.data[0]; |
33941284 | 209 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 210 | |
a263629d HX |
211 | tmpbuf[0] = htonl(conn->proto.epoch); |
212 | tmpbuf[1] = htonl(conn->proto.cid); | |
213 | tmpbuf[2] = 0; | |
214 | tmpbuf[3] = htonl(conn->security_ix); | |
1afe593b | 215 | |
a263629d | 216 | sg_init_one(&sg, tmpbuf, tmpsize); |
8d47a43c | 217 | skcipher_request_set_sync_tfm(req, ci); |
1afe593b | 218 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 219 | skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x); |
1afe593b | 220 | crypto_skcipher_encrypt(req); |
1db88c53 | 221 | skcipher_request_free(req); |
17926a79 | 222 | |
521bb304 | 223 | memcpy(&conn->rxkad.csum_iv, tmpbuf + 2, sizeof(conn->rxkad.csum_iv)); |
a263629d HX |
224 | kfree(tmpbuf); |
225 | _leave(" = 0"); | |
226 | return 0; | |
17926a79 DH |
227 | } |
228 | ||
1db88c53 DH |
229 | /* |
230 | * Allocate and prepare the crypto request on a call. For any particular call, | |
231 | * this is called serially for the packets, so no lock should be necessary. | |
232 | */ | |
233 | static struct skcipher_request *rxkad_get_call_crypto(struct rxrpc_call *call) | |
234 | { | |
521bb304 | 235 | struct crypto_skcipher *tfm = &call->conn->rxkad.cipher->base; |
1db88c53 | 236 | |
30d95efe | 237 | return skcipher_request_alloc(tfm, GFP_NOFS); |
1db88c53 DH |
238 | } |
239 | ||
240 | /* | |
241 | * Clean up the crypto on a call. | |
242 | */ | |
243 | static void rxkad_free_call_crypto(struct rxrpc_call *call) | |
244 | { | |
1db88c53 DH |
245 | } |
246 | ||
17926a79 DH |
247 | /* |
248 | * partially encrypt a packet (level 1 security) | |
249 | */ | |
250 | static int rxkad_secure_packet_auth(const struct rxrpc_call *call, | |
a4ea4c47 | 251 | struct rxrpc_txbuf *txb, |
54424d38 | 252 | struct skcipher_request *req) |
17926a79 | 253 | { |
a4ea4c47 | 254 | struct rxkad_level1_hdr *hdr = (void *)txb->data; |
17926a79 | 255 | struct rxrpc_crypt iv; |
a263629d | 256 | struct scatterlist sg; |
d7d775b1 | 257 | size_t pad; |
17926a79 DH |
258 | u16 check; |
259 | ||
17926a79 DH |
260 | _enter(""); |
261 | ||
a4ea4c47 DH |
262 | check = txb->seq ^ ntohl(txb->wire.callNumber); |
263 | hdr->data_size = htonl((u32)check << 16 | txb->len); | |
17926a79 | 264 | |
a4ea4c47 DH |
265 | txb->len += sizeof(struct rxkad_level1_hdr); |
266 | pad = txb->len; | |
d7d775b1 DH |
267 | pad = RXKAD_ALIGN - pad; |
268 | pad &= RXKAD_ALIGN - 1; | |
a4ea4c47 DH |
269 | if (pad) { |
270 | memset(txb->data + txb->offset, 0, pad); | |
271 | txb->len += pad; | |
272 | } | |
d7d775b1 | 273 | |
17926a79 DH |
274 | /* start the encryption afresh */ |
275 | memset(&iv, 0, sizeof(iv)); | |
17926a79 | 276 | |
a4ea4c47 | 277 | sg_init_one(&sg, txb->data, 8); |
521bb304 | 278 | skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher); |
1afe593b | 279 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 280 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
281 | crypto_skcipher_encrypt(req); |
282 | skcipher_request_zero(req); | |
17926a79 | 283 | |
17926a79 DH |
284 | _leave(" = 0"); |
285 | return 0; | |
286 | } | |
287 | ||
288 | /* | |
289 | * wholly encrypt a packet (level 2 security) | |
290 | */ | |
291 | static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call, | |
a4ea4c47 | 292 | struct rxrpc_txbuf *txb, |
54424d38 | 293 | struct skcipher_request *req) |
17926a79 | 294 | { |
33941284 | 295 | const struct rxrpc_key_token *token; |
a4ea4c47 | 296 | struct rxkad_level2_hdr *rxkhdr = (void *)txb->data; |
17926a79 | 297 | struct rxrpc_crypt iv; |
a4ea4c47 | 298 | struct scatterlist sg; |
d7d775b1 | 299 | size_t pad; |
17926a79 | 300 | u16 check; |
a4ea4c47 | 301 | int ret; |
17926a79 DH |
302 | |
303 | _enter(""); | |
304 | ||
a4ea4c47 | 305 | check = txb->seq ^ ntohl(txb->wire.callNumber); |
17926a79 | 306 | |
a4ea4c47 DH |
307 | rxkhdr->data_size = htonl(txb->len | (u32)check << 16); |
308 | rxkhdr->checksum = 0; | |
17926a79 | 309 | |
a4ea4c47 DH |
310 | txb->len += sizeof(struct rxkad_level2_hdr); |
311 | pad = txb->len; | |
d7d775b1 DH |
312 | pad = RXKAD_ALIGN - pad; |
313 | pad &= RXKAD_ALIGN - 1; | |
a4ea4c47 DH |
314 | if (pad) { |
315 | memset(txb->data + txb->offset, 0, pad); | |
316 | txb->len += pad; | |
317 | } | |
d7d775b1 | 318 | |
17926a79 | 319 | /* encrypt from the session key */ |
2cc80086 | 320 | token = call->conn->key->payload.data[0]; |
33941284 | 321 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 322 | |
a4ea4c47 | 323 | sg_init_one(&sg, txb->data, txb->len); |
521bb304 | 324 | skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher); |
1afe593b | 325 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a4ea4c47 DH |
326 | skcipher_request_set_crypt(req, &sg, &sg, txb->len, iv.x); |
327 | ret = crypto_skcipher_encrypt(req); | |
1afe593b | 328 | skcipher_request_zero(req); |
a4ea4c47 | 329 | return ret; |
17926a79 DH |
330 | } |
331 | ||
332 | /* | |
333 | * checksum an RxRPC packet header | |
334 | */ | |
a4ea4c47 | 335 | static int rxkad_secure_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb) |
17926a79 | 336 | { |
1db88c53 | 337 | struct skcipher_request *req; |
17926a79 | 338 | struct rxrpc_crypt iv; |
a263629d | 339 | struct scatterlist sg; |
30d95efe DH |
340 | union { |
341 | __be32 buf[2]; | |
342 | } crypto __aligned(8); | |
0d12f8a4 | 343 | u32 x, y; |
17926a79 DH |
344 | int ret; |
345 | ||
a4ea4c47 | 346 | _enter("{%d{%x}},{#%u},%u,", |
2cc80086 | 347 | call->debug_id, key_serial(call->conn->key), |
a4ea4c47 | 348 | txb->seq, txb->len); |
17926a79 | 349 | |
521bb304 | 350 | if (!call->conn->rxkad.cipher) |
17926a79 DH |
351 | return 0; |
352 | ||
2cc80086 | 353 | ret = key_validate(call->conn->key); |
17926a79 DH |
354 | if (ret < 0) |
355 | return ret; | |
356 | ||
1db88c53 DH |
357 | req = rxkad_get_call_crypto(call); |
358 | if (!req) | |
359 | return -ENOMEM; | |
360 | ||
17926a79 | 361 | /* continue encrypting from where we left off */ |
521bb304 | 362 | memcpy(&iv, call->conn->rxkad.csum_iv.x, sizeof(iv)); |
17926a79 DH |
363 | |
364 | /* calculate the security checksum */ | |
a4ea4c47 DH |
365 | x = (ntohl(txb->wire.cid) & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT); |
366 | x |= txb->seq & 0x3fffffff; | |
30d95efe DH |
367 | crypto.buf[0] = txb->wire.callNumber; |
368 | crypto.buf[1] = htonl(x); | |
1afe593b | 369 | |
30d95efe | 370 | sg_init_one(&sg, crypto.buf, 8); |
521bb304 | 371 | skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher); |
1afe593b | 372 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 373 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
374 | crypto_skcipher_encrypt(req); |
375 | skcipher_request_zero(req); | |
17926a79 | 376 | |
30d95efe | 377 | y = ntohl(crypto.buf[1]); |
91e916cf AV |
378 | y = (y >> 16) & 0xffff; |
379 | if (y == 0) | |
380 | y = 1; /* zero checksums are not permitted */ | |
a4ea4c47 | 381 | txb->wire.cksum = htons(y); |
17926a79 | 382 | |
2cc80086 | 383 | switch (call->conn->security_level) { |
17926a79 DH |
384 | case RXRPC_SECURITY_PLAIN: |
385 | ret = 0; | |
386 | break; | |
387 | case RXRPC_SECURITY_AUTH: | |
a4ea4c47 | 388 | ret = rxkad_secure_packet_auth(call, txb, req); |
17926a79 DH |
389 | break; |
390 | case RXRPC_SECURITY_ENCRYPT: | |
a4ea4c47 | 391 | ret = rxkad_secure_packet_encrypt(call, txb, req); |
17926a79 DH |
392 | break; |
393 | default: | |
394 | ret = -EPERM; | |
395 | break; | |
396 | } | |
397 | ||
30d95efe | 398 | skcipher_request_free(req); |
5b47d236 | 399 | _leave(" = %d [set %x]", ret, y); |
17926a79 DH |
400 | return ret; |
401 | } | |
402 | ||
403 | /* | |
404 | * decrypt partial encryption on a packet (level 1 security) | |
405 | */ | |
5a42976d | 406 | static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb, |
54424d38 KC |
407 | rxrpc_seq_t seq, |
408 | struct skcipher_request *req) | |
17926a79 DH |
409 | { |
410 | struct rxkad_level1_hdr sechdr; | |
d4d02d8b | 411 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 | 412 | struct rxrpc_crypt iv; |
68e3f5dd | 413 | struct scatterlist sg[16]; |
17926a79 DH |
414 | u32 data_size, buf; |
415 | u16 check; | |
d0d5c0cd | 416 | int ret; |
17926a79 DH |
417 | |
418 | _enter(""); | |
419 | ||
57af281e DH |
420 | if (sp->len < 8) |
421 | return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, | |
422 | rxkad_abort_1_short_header); | |
17926a79 | 423 | |
248f219c DH |
424 | /* Decrypt the skbuff in-place. TODO: We really want to decrypt |
425 | * directly into the target buffer. | |
426 | */ | |
d0d5c0cd | 427 | sg_init_table(sg, ARRAY_SIZE(sg)); |
d4d02d8b | 428 | ret = skb_to_sgvec(skb, sg, sp->offset, 8); |
89a5ea99 JD |
429 | if (unlikely(ret < 0)) |
430 | return ret; | |
17926a79 DH |
431 | |
432 | /* start the decryption afresh */ | |
433 | memset(&iv, 0, sizeof(iv)); | |
17926a79 | 434 | |
521bb304 | 435 | skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher); |
1afe593b HX |
436 | skcipher_request_set_callback(req, 0, NULL, NULL); |
437 | skcipher_request_set_crypt(req, sg, sg, 8, iv.x); | |
1afe593b HX |
438 | crypto_skcipher_decrypt(req); |
439 | skcipher_request_zero(req); | |
17926a79 | 440 | |
5a42976d | 441 | /* Extract the decrypted packet length */ |
57af281e DH |
442 | if (skb_copy_bits(skb, sp->offset, &sechdr, sizeof(sechdr)) < 0) |
443 | return rxrpc_abort_eproto(call, skb, RXKADDATALEN, | |
444 | rxkad_abort_1_short_encdata); | |
d4d02d8b DH |
445 | sp->offset += sizeof(sechdr); |
446 | sp->len -= sizeof(sechdr); | |
17926a79 DH |
447 | |
448 | buf = ntohl(sechdr.data_size); | |
449 | data_size = buf & 0xffff; | |
450 | ||
451 | check = buf >> 16; | |
5a42976d | 452 | check ^= seq ^ call->call_id; |
17926a79 | 453 | check &= 0xffff; |
57af281e DH |
454 | if (check != 0) |
455 | return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, | |
456 | rxkad_abort_1_short_check); | |
457 | if (data_size > sp->len) | |
458 | return rxrpc_abort_eproto(call, skb, RXKADDATALEN, | |
459 | rxkad_abort_1_short_data); | |
d4d02d8b | 460 | sp->len = data_size; |
17926a79 DH |
461 | |
462 | _leave(" = 0 [dlen=%x]", data_size); | |
463 | return 0; | |
17926a79 DH |
464 | } |
465 | ||
466 | /* | |
467 | * wholly decrypt a packet (level 2 security) | |
468 | */ | |
5a42976d | 469 | static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb, |
54424d38 KC |
470 | rxrpc_seq_t seq, |
471 | struct skcipher_request *req) | |
17926a79 | 472 | { |
33941284 | 473 | const struct rxrpc_key_token *token; |
17926a79 | 474 | struct rxkad_level2_hdr sechdr; |
d4d02d8b | 475 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 DH |
476 | struct rxrpc_crypt iv; |
477 | struct scatterlist _sg[4], *sg; | |
17926a79 DH |
478 | u32 data_size, buf; |
479 | u16 check; | |
89a5ea99 | 480 | int nsg, ret; |
17926a79 | 481 | |
d4d02d8b | 482 | _enter(",{%d}", sp->len); |
17926a79 | 483 | |
57af281e DH |
484 | if (sp->len < 8) |
485 | return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, | |
486 | rxkad_abort_2_short_header); | |
17926a79 | 487 | |
248f219c DH |
488 | /* Decrypt the skbuff in-place. TODO: We really want to decrypt |
489 | * directly into the target buffer. | |
490 | */ | |
17926a79 | 491 | sg = _sg; |
0d40f728 | 492 | nsg = skb_shinfo(skb)->nr_frags + 1; |
d0d5c0cd DH |
493 | if (nsg <= 4) { |
494 | nsg = 4; | |
495 | } else { | |
6da2ec56 | 496 | sg = kmalloc_array(nsg, sizeof(*sg), GFP_NOIO); |
17926a79 | 497 | if (!sg) |
57af281e | 498 | return -ENOMEM; |
17926a79 DH |
499 | } |
500 | ||
68e3f5dd | 501 | sg_init_table(sg, nsg); |
d4d02d8b | 502 | ret = skb_to_sgvec(skb, sg, sp->offset, sp->len); |
89a5ea99 JD |
503 | if (unlikely(ret < 0)) { |
504 | if (sg != _sg) | |
505 | kfree(sg); | |
506 | return ret; | |
507 | } | |
17926a79 DH |
508 | |
509 | /* decrypt from the session key */ | |
2cc80086 | 510 | token = call->conn->key->payload.data[0]; |
33941284 | 511 | memcpy(&iv, token->kad->session_key, sizeof(iv)); |
17926a79 | 512 | |
521bb304 | 513 | skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher); |
1afe593b | 514 | skcipher_request_set_callback(req, 0, NULL, NULL); |
d4d02d8b | 515 | skcipher_request_set_crypt(req, sg, sg, sp->len, iv.x); |
1afe593b HX |
516 | crypto_skcipher_decrypt(req); |
517 | skcipher_request_zero(req); | |
17926a79 DH |
518 | if (sg != _sg) |
519 | kfree(sg); | |
520 | ||
5a42976d | 521 | /* Extract the decrypted packet length */ |
57af281e DH |
522 | if (skb_copy_bits(skb, sp->offset, &sechdr, sizeof(sechdr)) < 0) |
523 | return rxrpc_abort_eproto(call, skb, RXKADDATALEN, | |
524 | rxkad_abort_2_short_len); | |
d4d02d8b DH |
525 | sp->offset += sizeof(sechdr); |
526 | sp->len -= sizeof(sechdr); | |
17926a79 DH |
527 | |
528 | buf = ntohl(sechdr.data_size); | |
529 | data_size = buf & 0xffff; | |
530 | ||
531 | check = buf >> 16; | |
5a42976d | 532 | check ^= seq ^ call->call_id; |
17926a79 | 533 | check &= 0xffff; |
57af281e DH |
534 | if (check != 0) |
535 | return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, | |
536 | rxkad_abort_2_short_check); | |
17926a79 | 537 | |
57af281e DH |
538 | if (data_size > sp->len) |
539 | return rxrpc_abort_eproto(call, skb, RXKADDATALEN, | |
540 | rxkad_abort_2_short_data); | |
17926a79 | 541 | |
d4d02d8b | 542 | sp->len = data_size; |
17926a79 DH |
543 | _leave(" = 0 [dlen=%x]", data_size); |
544 | return 0; | |
17926a79 DH |
545 | } |
546 | ||
547 | /* | |
d4d02d8b | 548 | * Verify the security on a received packet and the subpackets therein. |
17926a79 | 549 | */ |
d4d02d8b | 550 | static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb) |
17926a79 | 551 | { |
d4d02d8b | 552 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
1db88c53 | 553 | struct skcipher_request *req; |
17926a79 | 554 | struct rxrpc_crypt iv; |
a263629d | 555 | struct scatterlist sg; |
30d95efe DH |
556 | union { |
557 | __be32 buf[2]; | |
558 | } crypto __aligned(8); | |
d4d02d8b | 559 | rxrpc_seq_t seq = sp->hdr.seq; |
30d95efe | 560 | int ret; |
0d12f8a4 DH |
561 | u16 cksum; |
562 | u32 x, y; | |
17926a79 DH |
563 | |
564 | _enter("{%d{%x}},{#%u}", | |
2cc80086 | 565 | call->debug_id, key_serial(call->conn->key), seq); |
17926a79 | 566 | |
521bb304 | 567 | if (!call->conn->rxkad.cipher) |
17926a79 DH |
568 | return 0; |
569 | ||
1db88c53 DH |
570 | req = rxkad_get_call_crypto(call); |
571 | if (!req) | |
572 | return -ENOMEM; | |
573 | ||
17926a79 | 574 | /* continue encrypting from where we left off */ |
521bb304 | 575 | memcpy(&iv, call->conn->rxkad.csum_iv.x, sizeof(iv)); |
17926a79 DH |
576 | |
577 | /* validate the security checksum */ | |
01a90a45 | 578 | x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT); |
5a42976d | 579 | x |= seq & 0x3fffffff; |
30d95efe DH |
580 | crypto.buf[0] = htonl(call->call_id); |
581 | crypto.buf[1] = htonl(x); | |
1afe593b | 582 | |
30d95efe | 583 | sg_init_one(&sg, crypto.buf, 8); |
521bb304 | 584 | skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher); |
1afe593b | 585 | skcipher_request_set_callback(req, 0, NULL, NULL); |
a263629d | 586 | skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x); |
1afe593b HX |
587 | crypto_skcipher_encrypt(req); |
588 | skcipher_request_zero(req); | |
17926a79 | 589 | |
30d95efe | 590 | y = ntohl(crypto.buf[1]); |
0d12f8a4 DH |
591 | cksum = (y >> 16) & 0xffff; |
592 | if (cksum == 0) | |
593 | cksum = 1; /* zero checksums are not permitted */ | |
17926a79 | 594 | |
d4d02d8b | 595 | if (cksum != sp->hdr.cksum) { |
57af281e DH |
596 | ret = rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON, |
597 | rxkad_abort_bad_checksum); | |
598 | goto out; | |
17926a79 DH |
599 | } |
600 | ||
2cc80086 | 601 | switch (call->conn->security_level) { |
17926a79 | 602 | case RXRPC_SECURITY_PLAIN: |
30d95efe DH |
603 | ret = 0; |
604 | break; | |
17926a79 | 605 | case RXRPC_SECURITY_AUTH: |
30d95efe DH |
606 | ret = rxkad_verify_packet_1(call, skb, seq, req); |
607 | break; | |
17926a79 | 608 | case RXRPC_SECURITY_ENCRYPT: |
30d95efe DH |
609 | ret = rxkad_verify_packet_2(call, skb, seq, req); |
610 | break; | |
17926a79 | 611 | default: |
30d95efe DH |
612 | ret = -ENOANO; |
613 | break; | |
17926a79 | 614 | } |
fb46f6ee | 615 | |
57af281e | 616 | out: |
30d95efe DH |
617 | skcipher_request_free(req); |
618 | return ret; | |
17926a79 DH |
619 | } |
620 | ||
621 | /* | |
622 | * issue a challenge | |
623 | */ | |
624 | static int rxkad_issue_challenge(struct rxrpc_connection *conn) | |
625 | { | |
626 | struct rxkad_challenge challenge; | |
0d12f8a4 | 627 | struct rxrpc_wire_header whdr; |
17926a79 DH |
628 | struct msghdr msg; |
629 | struct kvec iov[2]; | |
630 | size_t len; | |
0d12f8a4 | 631 | u32 serial; |
17926a79 DH |
632 | int ret; |
633 | ||
ec832bd0 | 634 | _enter("{%d}", conn->debug_id); |
17926a79 | 635 | |
521bb304 | 636 | get_random_bytes(&conn->rxkad.nonce, sizeof(conn->rxkad.nonce)); |
17926a79 DH |
637 | |
638 | challenge.version = htonl(2); | |
521bb304 | 639 | challenge.nonce = htonl(conn->rxkad.nonce); |
17926a79 DH |
640 | challenge.min_level = htonl(0); |
641 | challenge.__padding = 0; | |
642 | ||
2cc80086 DH |
643 | msg.msg_name = &conn->peer->srx.transport; |
644 | msg.msg_namelen = conn->peer->srx.transport_len; | |
17926a79 DH |
645 | msg.msg_control = NULL; |
646 | msg.msg_controllen = 0; | |
647 | msg.msg_flags = 0; | |
648 | ||
19ffa01c DH |
649 | whdr.epoch = htonl(conn->proto.epoch); |
650 | whdr.cid = htonl(conn->proto.cid); | |
0d12f8a4 DH |
651 | whdr.callNumber = 0; |
652 | whdr.seq = 0; | |
653 | whdr.type = RXRPC_PACKET_TYPE_CHALLENGE; | |
654 | whdr.flags = conn->out_clientflag; | |
655 | whdr.userStatus = 0; | |
656 | whdr.securityIndex = conn->security_ix; | |
657 | whdr._rsvd = 0; | |
68d6d1ae | 658 | whdr.serviceId = htons(conn->service_id); |
0d12f8a4 DH |
659 | |
660 | iov[0].iov_base = &whdr; | |
661 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
662 | iov[1].iov_base = &challenge; |
663 | iov[1].iov_len = sizeof(challenge); | |
664 | ||
665 | len = iov[0].iov_len + iov[1].iov_len; | |
666 | ||
0d12f8a4 DH |
667 | serial = atomic_inc_return(&conn->serial); |
668 | whdr.serial = htonl(serial); | |
17926a79 | 669 | |
2cc80086 | 670 | ret = kernel_sendmsg(conn->local->socket, &msg, iov, 2, len); |
17926a79 | 671 | if (ret < 0) { |
6b47fe1d | 672 | trace_rxrpc_tx_fail(conn->debug_id, serial, ret, |
4764c0da | 673 | rxrpc_tx_point_rxkad_challenge); |
17926a79 DH |
674 | return -EAGAIN; |
675 | } | |
676 | ||
2cc80086 | 677 | conn->peer->last_tx_at = ktime_get_seconds(); |
4764c0da DH |
678 | trace_rxrpc_tx_packet(conn->debug_id, &whdr, |
679 | rxrpc_tx_point_rxkad_challenge); | |
17926a79 DH |
680 | _leave(" = 0"); |
681 | return 0; | |
682 | } | |
683 | ||
684 | /* | |
685 | * send a Kerberos security response | |
686 | */ | |
687 | static int rxkad_send_response(struct rxrpc_connection *conn, | |
0d12f8a4 | 688 | struct rxrpc_host_header *hdr, |
17926a79 DH |
689 | struct rxkad_response *resp, |
690 | const struct rxkad_key *s2) | |
691 | { | |
0d12f8a4 | 692 | struct rxrpc_wire_header whdr; |
17926a79 DH |
693 | struct msghdr msg; |
694 | struct kvec iov[3]; | |
695 | size_t len; | |
0d12f8a4 | 696 | u32 serial; |
17926a79 DH |
697 | int ret; |
698 | ||
699 | _enter(""); | |
700 | ||
2cc80086 DH |
701 | msg.msg_name = &conn->peer->srx.transport; |
702 | msg.msg_namelen = conn->peer->srx.transport_len; | |
17926a79 DH |
703 | msg.msg_control = NULL; |
704 | msg.msg_controllen = 0; | |
705 | msg.msg_flags = 0; | |
706 | ||
0d12f8a4 DH |
707 | memset(&whdr, 0, sizeof(whdr)); |
708 | whdr.epoch = htonl(hdr->epoch); | |
709 | whdr.cid = htonl(hdr->cid); | |
710 | whdr.type = RXRPC_PACKET_TYPE_RESPONSE; | |
711 | whdr.flags = conn->out_clientflag; | |
712 | whdr.securityIndex = hdr->securityIndex; | |
713 | whdr.serviceId = htons(hdr->serviceId); | |
17926a79 | 714 | |
0d12f8a4 DH |
715 | iov[0].iov_base = &whdr; |
716 | iov[0].iov_len = sizeof(whdr); | |
17926a79 DH |
717 | iov[1].iov_base = resp; |
718 | iov[1].iov_len = sizeof(*resp); | |
0d12f8a4 | 719 | iov[2].iov_base = (void *)s2->ticket; |
17926a79 DH |
720 | iov[2].iov_len = s2->ticket_len; |
721 | ||
722 | len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len; | |
723 | ||
0d12f8a4 DH |
724 | serial = atomic_inc_return(&conn->serial); |
725 | whdr.serial = htonl(serial); | |
17926a79 | 726 | |
2cc80086 | 727 | ret = kernel_sendmsg(conn->local->socket, &msg, iov, 3, len); |
17926a79 | 728 | if (ret < 0) { |
6b47fe1d | 729 | trace_rxrpc_tx_fail(conn->debug_id, serial, ret, |
4764c0da | 730 | rxrpc_tx_point_rxkad_response); |
17926a79 DH |
731 | return -EAGAIN; |
732 | } | |
733 | ||
2cc80086 | 734 | conn->peer->last_tx_at = ktime_get_seconds(); |
17926a79 DH |
735 | _leave(" = 0"); |
736 | return 0; | |
737 | } | |
738 | ||
739 | /* | |
740 | * calculate the response checksum | |
741 | */ | |
742 | static void rxkad_calc_response_checksum(struct rxkad_response *response) | |
743 | { | |
744 | u32 csum = 1000003; | |
745 | int loop; | |
746 | u8 *p = (u8 *) response; | |
747 | ||
748 | for (loop = sizeof(*response); loop > 0; loop--) | |
749 | csum = csum * 0x10204081 + *p++; | |
750 | ||
751 | response->encrypted.checksum = htonl(csum); | |
752 | } | |
753 | ||
17926a79 DH |
754 | /* |
755 | * encrypt the response packet | |
756 | */ | |
1db88c53 DH |
757 | static int rxkad_encrypt_response(struct rxrpc_connection *conn, |
758 | struct rxkad_response *resp, | |
759 | const struct rxkad_key *s2) | |
17926a79 | 760 | { |
1db88c53 | 761 | struct skcipher_request *req; |
17926a79 | 762 | struct rxrpc_crypt iv; |
a263629d | 763 | struct scatterlist sg[1]; |
17926a79 | 764 | |
521bb304 | 765 | req = skcipher_request_alloc(&conn->rxkad.cipher->base, GFP_NOFS); |
1db88c53 DH |
766 | if (!req) |
767 | return -ENOMEM; | |
768 | ||
17926a79 DH |
769 | /* continue encrypting from where we left off */ |
770 | memcpy(&iv, s2->session_key, sizeof(iv)); | |
17926a79 | 771 | |
a263629d HX |
772 | sg_init_table(sg, 1); |
773 | sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted)); | |
521bb304 | 774 | skcipher_request_set_sync_tfm(req, conn->rxkad.cipher); |
1afe593b HX |
775 | skcipher_request_set_callback(req, 0, NULL, NULL); |
776 | skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x); | |
1afe593b | 777 | crypto_skcipher_encrypt(req); |
1db88c53 DH |
778 | skcipher_request_free(req); |
779 | return 0; | |
17926a79 DH |
780 | } |
781 | ||
782 | /* | |
783 | * respond to a challenge packet | |
784 | */ | |
785 | static int rxkad_respond_to_challenge(struct rxrpc_connection *conn, | |
a00ce28b | 786 | struct sk_buff *skb) |
17926a79 | 787 | { |
33941284 | 788 | const struct rxrpc_key_token *token; |
17926a79 | 789 | struct rxkad_challenge challenge; |
8c2f826d | 790 | struct rxkad_response *resp; |
248f219c | 791 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
57af281e DH |
792 | u32 version, nonce, min_level; |
793 | int ret = -EPROTO; | |
17926a79 | 794 | |
2cc80086 | 795 | _enter("{%d,%x}", conn->debug_id, key_serial(conn->key)); |
17926a79 | 796 | |
2cc80086 | 797 | if (!conn->key) |
57af281e DH |
798 | return rxrpc_abort_conn(conn, skb, RX_PROTOCOL_ERROR, -EPROTO, |
799 | rxkad_abort_chall_no_key); | |
17926a79 | 800 | |
2cc80086 | 801 | ret = key_validate(conn->key); |
ef68622d | 802 | if (ret < 0) |
57af281e DH |
803 | return rxrpc_abort_conn(conn, skb, RXKADEXPIRED, ret, |
804 | rxkad_abort_chall_key_expired); | |
17926a79 | 805 | |
775e5b71 DH |
806 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
807 | &challenge, sizeof(challenge)) < 0) | |
57af281e DH |
808 | return rxrpc_abort_conn(conn, skb, RXKADPACKETSHORT, -EPROTO, |
809 | rxkad_abort_chall_short); | |
17926a79 DH |
810 | |
811 | version = ntohl(challenge.version); | |
812 | nonce = ntohl(challenge.nonce); | |
813 | min_level = ntohl(challenge.min_level); | |
814 | ||
2ebdb26e | 815 | trace_rxrpc_rx_challenge(conn, sp->hdr.serial, version, nonce, min_level); |
17926a79 | 816 | |
17926a79 | 817 | if (version != RXKAD_VERSION) |
57af281e DH |
818 | return rxrpc_abort_conn(conn, skb, RXKADINCONSISTENCY, -EPROTO, |
819 | rxkad_abort_chall_version); | |
17926a79 | 820 | |
2cc80086 | 821 | if (conn->security_level < min_level) |
57af281e DH |
822 | return rxrpc_abort_conn(conn, skb, RXKADLEVELFAIL, -EACCES, |
823 | rxkad_abort_chall_level); | |
17926a79 | 824 | |
2cc80086 | 825 | token = conn->key->payload.data[0]; |
17926a79 DH |
826 | |
827 | /* build the response packet */ | |
8c2f826d DH |
828 | resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS); |
829 | if (!resp) | |
830 | return -ENOMEM; | |
831 | ||
832 | resp->version = htonl(RXKAD_VERSION); | |
833 | resp->encrypted.epoch = htonl(conn->proto.epoch); | |
834 | resp->encrypted.cid = htonl(conn->proto.cid); | |
835 | resp->encrypted.securityIndex = htonl(conn->security_ix); | |
836 | resp->encrypted.inc_nonce = htonl(nonce + 1); | |
2cc80086 | 837 | resp->encrypted.level = htonl(conn->security_level); |
8c2f826d DH |
838 | resp->kvno = htonl(token->kad->kvno); |
839 | resp->ticket_len = htonl(token->kad->ticket_len); | |
840 | resp->encrypted.call_id[0] = htonl(conn->channels[0].call_counter); | |
841 | resp->encrypted.call_id[1] = htonl(conn->channels[1].call_counter); | |
842 | resp->encrypted.call_id[2] = htonl(conn->channels[2].call_counter); | |
843 | resp->encrypted.call_id[3] = htonl(conn->channels[3].call_counter); | |
17926a79 DH |
844 | |
845 | /* calculate the response checksum and then do the encryption */ | |
8c2f826d | 846 | rxkad_calc_response_checksum(resp); |
1db88c53 DH |
847 | ret = rxkad_encrypt_response(conn, resp, token->kad); |
848 | if (ret == 0) | |
849 | ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad); | |
8c2f826d DH |
850 | kfree(resp); |
851 | return ret; | |
17926a79 DH |
852 | } |
853 | ||
854 | /* | |
855 | * decrypt the kerberos IV ticket in the response | |
856 | */ | |
857 | static int rxkad_decrypt_ticket(struct rxrpc_connection *conn, | |
ec832bd0 | 858 | struct key *server_key, |
fb46f6ee | 859 | struct sk_buff *skb, |
17926a79 DH |
860 | void *ticket, size_t ticket_len, |
861 | struct rxrpc_crypt *_session_key, | |
a00ce28b | 862 | time64_t *_expiry) |
17926a79 | 863 | { |
1afe593b | 864 | struct skcipher_request *req; |
17926a79 | 865 | struct rxrpc_crypt iv, key; |
68e3f5dd | 866 | struct scatterlist sg[1]; |
17926a79 | 867 | struct in_addr addr; |
95c96174 | 868 | unsigned int life; |
10674a03 | 869 | time64_t issue, now; |
17926a79 | 870 | bool little_endian; |
17926a79 DH |
871 | u8 *p, *q, *name, *end; |
872 | ||
ec832bd0 | 873 | _enter("{%d},{%x}", conn->debug_id, key_serial(server_key)); |
17926a79 DH |
874 | |
875 | *_expiry = 0; | |
876 | ||
ec832bd0 | 877 | ASSERT(server_key->payload.data[0] != NULL); |
17926a79 DH |
878 | ASSERTCMP((unsigned long) ticket & 7UL, ==, 0); |
879 | ||
ec832bd0 | 880 | memcpy(&iv, &server_key->payload.data[2], sizeof(iv)); |
17926a79 | 881 | |
ec832bd0 | 882 | req = skcipher_request_alloc(server_key->payload.data[0], GFP_NOFS); |
ef68622d | 883 | if (!req) |
57af281e | 884 | return -ENOMEM; |
17926a79 | 885 | |
68e3f5dd | 886 | sg_init_one(&sg[0], ticket, ticket_len); |
1afe593b HX |
887 | skcipher_request_set_callback(req, 0, NULL, NULL); |
888 | skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x); | |
1afe593b HX |
889 | crypto_skcipher_decrypt(req); |
890 | skcipher_request_free(req); | |
17926a79 DH |
891 | |
892 | p = ticket; | |
893 | end = p + ticket_len; | |
894 | ||
57af281e DH |
895 | #define Z(field, fieldl) \ |
896 | ({ \ | |
897 | u8 *__str = p; \ | |
898 | q = memchr(p, 0, end - p); \ | |
899 | if (!q || q - p > field##_SZ) \ | |
900 | return rxrpc_abort_conn( \ | |
901 | conn, skb, RXKADBADTICKET, -EPROTO, \ | |
902 | rxkad_abort_resp_tkt_##fieldl); \ | |
903 | for (; p < q; p++) \ | |
904 | if (!isprint(*p)) \ | |
905 | return rxrpc_abort_conn( \ | |
906 | conn, skb, RXKADBADTICKET, -EPROTO, \ | |
907 | rxkad_abort_resp_tkt_##fieldl); \ | |
908 | p++; \ | |
909 | __str; \ | |
17926a79 DH |
910 | }) |
911 | ||
912 | /* extract the ticket flags */ | |
913 | _debug("KIV FLAGS: %x", *p); | |
914 | little_endian = *p & 1; | |
915 | p++; | |
916 | ||
917 | /* extract the authentication name */ | |
57af281e | 918 | name = Z(ANAME, aname); |
17926a79 DH |
919 | _debug("KIV ANAME: %s", name); |
920 | ||
921 | /* extract the principal's instance */ | |
57af281e | 922 | name = Z(INST, inst); |
17926a79 DH |
923 | _debug("KIV INST : %s", name); |
924 | ||
925 | /* extract the principal's authentication domain */ | |
57af281e | 926 | name = Z(REALM, realm); |
17926a79 DH |
927 | _debug("KIV REALM: %s", name); |
928 | ||
929 | if (end - p < 4 + 8 + 4 + 2) | |
57af281e DH |
930 | return rxrpc_abort_conn(conn, skb, RXKADBADTICKET, -EPROTO, |
931 | rxkad_abort_resp_tkt_short); | |
17926a79 DH |
932 | |
933 | /* get the IPv4 address of the entity that requested the ticket */ | |
934 | memcpy(&addr, p, sizeof(addr)); | |
935 | p += 4; | |
21454aaa | 936 | _debug("KIV ADDR : %pI4", &addr); |
17926a79 DH |
937 | |
938 | /* get the session key from the ticket */ | |
939 | memcpy(&key, p, sizeof(key)); | |
940 | p += 8; | |
941 | _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1])); | |
942 | memcpy(_session_key, &key, sizeof(key)); | |
943 | ||
944 | /* get the ticket's lifetime */ | |
945 | life = *p++ * 5 * 60; | |
946 | _debug("KIV LIFE : %u", life); | |
947 | ||
948 | /* get the issue time of the ticket */ | |
949 | if (little_endian) { | |
950 | __le32 stamp; | |
951 | memcpy(&stamp, p, 4); | |
10674a03 | 952 | issue = rxrpc_u32_to_time64(le32_to_cpu(stamp)); |
17926a79 DH |
953 | } else { |
954 | __be32 stamp; | |
955 | memcpy(&stamp, p, 4); | |
10674a03 | 956 | issue = rxrpc_u32_to_time64(be32_to_cpu(stamp)); |
17926a79 DH |
957 | } |
958 | p += 4; | |
10674a03 BW |
959 | now = ktime_get_real_seconds(); |
960 | _debug("KIV ISSUE: %llx [%llx]", issue, now); | |
17926a79 DH |
961 | |
962 | /* check the ticket is in date */ | |
57af281e DH |
963 | if (issue > now) |
964 | return rxrpc_abort_conn(conn, skb, RXKADNOAUTH, -EKEYREJECTED, | |
965 | rxkad_abort_resp_tkt_future); | |
966 | if (issue < now - life) | |
967 | return rxrpc_abort_conn(conn, skb, RXKADEXPIRED, -EKEYEXPIRED, | |
968 | rxkad_abort_resp_tkt_expired); | |
17926a79 DH |
969 | |
970 | *_expiry = issue + life; | |
971 | ||
972 | /* get the service name */ | |
57af281e | 973 | name = Z(SNAME, sname); |
17926a79 DH |
974 | _debug("KIV SNAME: %s", name); |
975 | ||
976 | /* get the service instance name */ | |
57af281e | 977 | name = Z(INST, sinst); |
17926a79 | 978 | _debug("KIV SINST: %s", name); |
ef68622d | 979 | return 0; |
17926a79 DH |
980 | } |
981 | ||
982 | /* | |
983 | * decrypt the response packet | |
984 | */ | |
985 | static void rxkad_decrypt_response(struct rxrpc_connection *conn, | |
986 | struct rxkad_response *resp, | |
987 | const struct rxrpc_crypt *session_key) | |
988 | { | |
1db88c53 | 989 | struct skcipher_request *req = rxkad_ci_req; |
a263629d | 990 | struct scatterlist sg[1]; |
17926a79 DH |
991 | struct rxrpc_crypt iv; |
992 | ||
993 | _enter(",,%08x%08x", | |
994 | ntohl(session_key->n[0]), ntohl(session_key->n[1])); | |
995 | ||
17926a79 | 996 | mutex_lock(&rxkad_ci_mutex); |
69d826fa | 997 | if (crypto_sync_skcipher_setkey(rxkad_ci, session_key->x, |
1db88c53 | 998 | sizeof(*session_key)) < 0) |
17926a79 DH |
999 | BUG(); |
1000 | ||
1001 | memcpy(&iv, session_key, sizeof(iv)); | |
17926a79 | 1002 | |
a263629d HX |
1003 | sg_init_table(sg, 1); |
1004 | sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted)); | |
69d826fa | 1005 | skcipher_request_set_sync_tfm(req, rxkad_ci); |
1afe593b HX |
1006 | skcipher_request_set_callback(req, 0, NULL, NULL); |
1007 | skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x); | |
1afe593b HX |
1008 | crypto_skcipher_decrypt(req); |
1009 | skcipher_request_zero(req); | |
1010 | ||
17926a79 DH |
1011 | mutex_unlock(&rxkad_ci_mutex); |
1012 | ||
1013 | _leave(""); | |
1014 | } | |
1015 | ||
1016 | /* | |
1017 | * verify a response | |
1018 | */ | |
1019 | static int rxkad_verify_response(struct rxrpc_connection *conn, | |
a00ce28b | 1020 | struct sk_buff *skb) |
17926a79 | 1021 | { |
8c2f826d | 1022 | struct rxkad_response *response; |
248f219c | 1023 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
17926a79 | 1024 | struct rxrpc_crypt session_key; |
ec832bd0 | 1025 | struct key *server_key; |
10674a03 | 1026 | time64_t expiry; |
17926a79 | 1027 | void *ticket; |
57af281e | 1028 | u32 version, kvno, ticket_len, level; |
91e916cf | 1029 | __be32 csum; |
a1399f8b | 1030 | int ret, i; |
17926a79 | 1031 | |
ec832bd0 DH |
1032 | _enter("{%d}", conn->debug_id); |
1033 | ||
1034 | server_key = rxrpc_look_up_server_security(conn, skb, 0, 0); | |
1035 | if (IS_ERR(server_key)) { | |
57af281e DH |
1036 | ret = PTR_ERR(server_key); |
1037 | switch (ret) { | |
ec832bd0 | 1038 | case -ENOKEY: |
57af281e DH |
1039 | return rxrpc_abort_conn(conn, skb, RXKADUNKNOWNKEY, ret, |
1040 | rxkad_abort_resp_nokey); | |
ec832bd0 | 1041 | case -EKEYEXPIRED: |
57af281e DH |
1042 | return rxrpc_abort_conn(conn, skb, RXKADEXPIRED, ret, |
1043 | rxkad_abort_resp_key_expired); | |
ec832bd0 | 1044 | default: |
57af281e DH |
1045 | return rxrpc_abort_conn(conn, skb, RXKADNOAUTH, ret, |
1046 | rxkad_abort_resp_key_rejected); | |
ec832bd0 | 1047 | } |
ec832bd0 | 1048 | } |
17926a79 | 1049 | |
8c2f826d DH |
1050 | ret = -ENOMEM; |
1051 | response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS); | |
1052 | if (!response) | |
1053 | goto temporary_error; | |
1054 | ||
775e5b71 | 1055 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
57af281e DH |
1056 | response, sizeof(*response)) < 0) { |
1057 | rxrpc_abort_conn(conn, skb, RXKADPACKETSHORT, -EPROTO, | |
1058 | rxkad_abort_resp_short); | |
17926a79 | 1059 | goto protocol_error; |
57af281e | 1060 | } |
17926a79 | 1061 | |
8c2f826d DH |
1062 | version = ntohl(response->version); |
1063 | ticket_len = ntohl(response->ticket_len); | |
1064 | kvno = ntohl(response->kvno); | |
2ebdb26e DH |
1065 | |
1066 | trace_rxrpc_rx_response(conn, sp->hdr.serial, version, kvno, ticket_len); | |
17926a79 | 1067 | |
57af281e DH |
1068 | if (version != RXKAD_VERSION) { |
1069 | rxrpc_abort_conn(conn, skb, RXKADINCONSISTENCY, -EPROTO, | |
1070 | rxkad_abort_resp_version); | |
4aa9cb32 | 1071 | goto protocol_error; |
57af281e | 1072 | } |
17926a79 | 1073 | |
57af281e DH |
1074 | if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN) { |
1075 | rxrpc_abort_conn(conn, skb, RXKADTICKETLEN, -EPROTO, | |
1076 | rxkad_abort_resp_tkt_len); | |
17926a79 | 1077 | goto protocol_error; |
57af281e | 1078 | } |
17926a79 | 1079 | |
57af281e DH |
1080 | if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5) { |
1081 | rxrpc_abort_conn(conn, skb, RXKADUNKNOWNKEY, -EPROTO, | |
1082 | rxkad_abort_resp_unknown_tkt); | |
17926a79 | 1083 | goto protocol_error; |
57af281e | 1084 | } |
17926a79 DH |
1085 | |
1086 | /* extract the kerberos ticket and decrypt and decode it */ | |
ef68622d | 1087 | ret = -ENOMEM; |
17926a79 DH |
1088 | ticket = kmalloc(ticket_len, GFP_NOFS); |
1089 | if (!ticket) | |
b43c75ab | 1090 | goto temporary_error_free_resp; |
17926a79 | 1091 | |
57af281e DH |
1092 | if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header) + sizeof(*response), |
1093 | ticket, ticket_len) < 0) { | |
1094 | rxrpc_abort_conn(conn, skb, RXKADPACKETSHORT, -EPROTO, | |
1095 | rxkad_abort_resp_short_tkt); | |
1096 | goto protocol_error; | |
1097 | } | |
17926a79 | 1098 | |
ec832bd0 | 1099 | ret = rxkad_decrypt_ticket(conn, server_key, skb, ticket, ticket_len, |
a00ce28b | 1100 | &session_key, &expiry); |
ef68622d | 1101 | if (ret < 0) |
f45d01f4 | 1102 | goto temporary_error_free_ticket; |
17926a79 DH |
1103 | |
1104 | /* use the session key from inside the ticket to decrypt the | |
1105 | * response */ | |
8c2f826d | 1106 | rxkad_decrypt_response(conn, response, &session_key); |
17926a79 | 1107 | |
57af281e DH |
1108 | if (ntohl(response->encrypted.epoch) != conn->proto.epoch || |
1109 | ntohl(response->encrypted.cid) != conn->proto.cid || | |
1110 | ntohl(response->encrypted.securityIndex) != conn->security_ix) { | |
1111 | rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO, | |
1112 | rxkad_abort_resp_bad_param); | |
17926a79 | 1113 | goto protocol_error_free; |
57af281e DH |
1114 | } |
1115 | ||
8c2f826d DH |
1116 | csum = response->encrypted.checksum; |
1117 | response->encrypted.checksum = 0; | |
1118 | rxkad_calc_response_checksum(response); | |
57af281e DH |
1119 | if (response->encrypted.checksum != csum) { |
1120 | rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO, | |
1121 | rxkad_abort_resp_bad_checksum); | |
17926a79 | 1122 | goto protocol_error_free; |
57af281e | 1123 | } |
17926a79 | 1124 | |
a1399f8b | 1125 | for (i = 0; i < RXRPC_MAXCALLS; i++) { |
8c2f826d | 1126 | u32 call_id = ntohl(response->encrypted.call_id[i]); |
9d35d880 | 1127 | u32 counter = READ_ONCE(conn->channels[i].call_counter); |
a1399f8b | 1128 | |
57af281e DH |
1129 | if (call_id > INT_MAX) { |
1130 | rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO, | |
1131 | rxkad_abort_resp_bad_callid); | |
9d35d880 | 1132 | goto protocol_error_free; |
57af281e | 1133 | } |
a1399f8b | 1134 | |
9d35d880 | 1135 | if (call_id < counter) { |
57af281e DH |
1136 | rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO, |
1137 | rxkad_abort_resp_call_ctr); | |
9d35d880 | 1138 | goto protocol_error_free; |
57af281e | 1139 | } |
fb46f6ee | 1140 | |
9d35d880 DH |
1141 | if (call_id > counter) { |
1142 | if (conn->channels[i].call) { | |
57af281e DH |
1143 | rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO, |
1144 | rxkad_abort_resp_call_state); | |
9d35d880 | 1145 | goto protocol_error_free; |
57af281e | 1146 | } |
a1399f8b DH |
1147 | conn->channels[i].call_counter = call_id; |
1148 | } | |
1149 | } | |
17926a79 | 1150 | |
57af281e DH |
1151 | if (ntohl(response->encrypted.inc_nonce) != conn->rxkad.nonce + 1) { |
1152 | rxrpc_abort_conn(conn, skb, RXKADOUTOFSEQUENCE, -EPROTO, | |
1153 | rxkad_abort_resp_ooseq); | |
17926a79 | 1154 | goto protocol_error_free; |
57af281e | 1155 | } |
17926a79 | 1156 | |
8c2f826d | 1157 | level = ntohl(response->encrypted.level); |
57af281e DH |
1158 | if (level > RXRPC_SECURITY_ENCRYPT) { |
1159 | rxrpc_abort_conn(conn, skb, RXKADLEVELFAIL, -EPROTO, | |
1160 | rxkad_abort_resp_level); | |
17926a79 | 1161 | goto protocol_error_free; |
57af281e | 1162 | } |
2cc80086 | 1163 | conn->security_level = level; |
17926a79 DH |
1164 | |
1165 | /* create a key to hold the security data and expiration time - after | |
1166 | * this the connection security can be handled in exactly the same way | |
1167 | * as for a client connection */ | |
1168 | ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno); | |
ef68622d | 1169 | if (ret < 0) |
8c2f826d | 1170 | goto temporary_error_free_ticket; |
17926a79 DH |
1171 | |
1172 | kfree(ticket); | |
8c2f826d | 1173 | kfree(response); |
17926a79 DH |
1174 | _leave(" = 0"); |
1175 | return 0; | |
1176 | ||
1177 | protocol_error_free: | |
1178 | kfree(ticket); | |
1179 | protocol_error: | |
8c2f826d | 1180 | kfree(response); |
ec832bd0 | 1181 | key_put(server_key); |
57af281e | 1182 | return -EPROTO; |
ef68622d | 1183 | |
8c2f826d | 1184 | temporary_error_free_ticket: |
ef68622d | 1185 | kfree(ticket); |
b43c75ab | 1186 | temporary_error_free_resp: |
8c2f826d | 1187 | kfree(response); |
ef68622d DH |
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 | */ | |
ec832bd0 | 1193 | key_put(server_key); |
ef68622d | 1194 | return ret; |
17926a79 DH |
1195 | } |
1196 | ||
1197 | /* | |
1198 | * clear the connection security | |
1199 | */ | |
1200 | static void rxkad_clear(struct rxrpc_connection *conn) | |
1201 | { | |
1202 | _enter(""); | |
1203 | ||
521bb304 DH |
1204 | if (conn->rxkad.cipher) |
1205 | crypto_free_sync_skcipher(conn->rxkad.cipher); | |
17926a79 DH |
1206 | } |
1207 | ||
648af7fc DH |
1208 | /* |
1209 | * Initialise the rxkad security service. | |
1210 | */ | |
1211 | static int rxkad_init(void) | |
1212 | { | |
1db88c53 DH |
1213 | struct crypto_sync_skcipher *tfm; |
1214 | struct skcipher_request *req; | |
1215 | ||
648af7fc DH |
1216 | /* pin the cipher we need so that the crypto layer doesn't invoke |
1217 | * keventd to go get it */ | |
1db88c53 DH |
1218 | tfm = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0); |
1219 | if (IS_ERR(tfm)) | |
1220 | return PTR_ERR(tfm); | |
1221 | ||
1222 | req = skcipher_request_alloc(&tfm->base, GFP_KERNEL); | |
1223 | if (!req) | |
1224 | goto nomem_tfm; | |
1225 | ||
1226 | rxkad_ci_req = req; | |
1227 | rxkad_ci = tfm; | |
1228 | return 0; | |
1229 | ||
1230 | nomem_tfm: | |
1231 | crypto_free_sync_skcipher(tfm); | |
1232 | return -ENOMEM; | |
648af7fc DH |
1233 | } |
1234 | ||
1235 | /* | |
1236 | * Clean up the rxkad security service. | |
1237 | */ | |
1238 | static void rxkad_exit(void) | |
1239 | { | |
1db88c53 DH |
1240 | crypto_free_sync_skcipher(rxkad_ci); |
1241 | skcipher_request_free(rxkad_ci_req); | |
648af7fc DH |
1242 | } |
1243 | ||
17926a79 DH |
1244 | /* |
1245 | * RxRPC Kerberos-based security | |
1246 | */ | |
648af7fc | 1247 | const struct rxrpc_security rxkad = { |
17926a79 | 1248 | .name = "rxkad", |
8b815477 | 1249 | .security_index = RXRPC_SECURITY_RXKAD, |
063c60d3 | 1250 | .no_key_abort = RXKADUNKNOWNKEY, |
648af7fc DH |
1251 | .init = rxkad_init, |
1252 | .exit = rxkad_exit, | |
12da59fc DH |
1253 | .preparse_server_key = rxkad_preparse_server_key, |
1254 | .free_preparse_server_key = rxkad_free_preparse_server_key, | |
1255 | .destroy_server_key = rxkad_destroy_server_key, | |
17926a79 | 1256 | .init_connection_security = rxkad_init_connection_security, |
d7d775b1 | 1257 | .how_much_data = rxkad_how_much_data, |
17926a79 DH |
1258 | .secure_packet = rxkad_secure_packet, |
1259 | .verify_packet = rxkad_verify_packet, | |
1db88c53 | 1260 | .free_call_crypto = rxkad_free_call_crypto, |
17926a79 DH |
1261 | .issue_challenge = rxkad_issue_challenge, |
1262 | .respond_to_challenge = rxkad_respond_to_challenge, | |
1263 | .verify_response = rxkad_verify_response, | |
1264 | .clear = rxkad_clear, | |
1265 | }; |