Commit | Line | Data |
---|---|---|
81d4a433 KC |
1 | /* |
2 | * COPYRIGHT (c) 2008 | |
3 | * The Regents of the University of Michigan | |
4 | * ALL RIGHTS RESERVED | |
5 | * | |
6 | * Permission is granted to use, copy, create derivative works | |
7 | * and redistribute this software and such derivative works | |
8 | * for any purpose, so long as the name of The University of | |
9 | * Michigan is not used in any advertising or publicity | |
10 | * pertaining to the use of distribution of this software | |
11 | * without specific, written prior authorization. If the | |
12 | * above copyright notice or any other identification of the | |
13 | * University of Michigan is included in any copy of any | |
14 | * portion of this software, then the disclaimer below must | |
15 | * also be included. | |
16 | * | |
17 | * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION | |
18 | * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY | |
19 | * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF | |
20 | * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING | |
21 | * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF | |
22 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE | |
23 | * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE | |
24 | * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR | |
25 | * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING | |
26 | * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN | |
27 | * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF | |
28 | * SUCH DAMAGES. | |
29 | */ | |
30 | ||
3b5cf20c | 31 | #include <crypto/skcipher.h> |
14ae162c | 32 | #include <linux/types.h> |
14ae162c BF |
33 | #include <linux/jiffies.h> |
34 | #include <linux/sunrpc/gss_krb5.h> | |
35 | #include <linux/random.h> | |
36 | #include <linux/pagemap.h> | |
14ae162c | 37 | |
f895b252 | 38 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
14ae162c BF |
39 | # define RPCDBG_FACILITY RPCDBG_AUTH |
40 | #endif | |
41 | ||
42 | static inline int | |
43 | gss_krb5_padding(int blocksize, int length) | |
44 | { | |
54ec3d46 | 45 | return blocksize - (length % blocksize); |
14ae162c BF |
46 | } |
47 | ||
48 | static inline void | |
49 | gss_krb5_add_padding(struct xdr_buf *buf, int offset, int blocksize) | |
50 | { | |
51 | int padding = gss_krb5_padding(blocksize, buf->len - offset); | |
52 | char *p; | |
53 | struct kvec *iov; | |
54 | ||
55 | if (buf->page_len || buf->tail[0].iov_len) | |
56 | iov = &buf->tail[0]; | |
57 | else | |
58 | iov = &buf->head[0]; | |
59 | p = iov->iov_base + iov->iov_len; | |
60 | iov->iov_len += padding; | |
61 | buf->len += padding; | |
62 | memset(p, padding, padding); | |
63 | } | |
64 | ||
65 | static inline int | |
66 | gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize) | |
67 | { | |
68 | u8 *ptr; | |
69 | u8 pad; | |
67f97d83 | 70 | size_t len = buf->len; |
14ae162c BF |
71 | |
72 | if (len <= buf->head[0].iov_len) { | |
73 | pad = *(u8 *)(buf->head[0].iov_base + len - 1); | |
74 | if (pad > buf->head[0].iov_len) | |
75 | return -EINVAL; | |
76 | buf->head[0].iov_len -= pad; | |
77 | goto out; | |
78 | } else | |
79 | len -= buf->head[0].iov_len; | |
80 | if (len <= buf->page_len) { | |
67f97d83 | 81 | unsigned int last = (buf->page_base + len - 1) |
09cbfeaf | 82 | >>PAGE_SHIFT; |
67f97d83 | 83 | unsigned int offset = (buf->page_base + len - 1) |
09cbfeaf | 84 | & (PAGE_SIZE - 1); |
b8541786 | 85 | ptr = kmap_atomic(buf->pages[last]); |
14ae162c | 86 | pad = *(ptr + offset); |
b8541786 | 87 | kunmap_atomic(ptr); |
14ae162c BF |
88 | goto out; |
89 | } else | |
90 | len -= buf->page_len; | |
91 | BUG_ON(len > buf->tail[0].iov_len); | |
92 | pad = *(u8 *)(buf->tail[0].iov_base + len - 1); | |
93 | out: | |
94 | /* XXX: NOTE: we do not adjust the page lengths--they represent | |
95 | * a range of data in the real filesystem page cache, and we need | |
96 | * to know that range so the xdr code can properly place read data. | |
97 | * However adjusting the head length, as we do above, is harmless. | |
98 | * In the case of a request that fits into a single page, the server | |
99 | * also uses length and head length together to determine the original | |
100 | * start of the request to copy the request for deferal; so it's | |
101 | * easier on the server if we adjust head and tail length in tandem. | |
102 | * It's not really a problem that we don't fool with the page and | |
103 | * tail lengths, though--at worst badly formed xdr might lead the | |
104 | * server to attempt to parse the padding. | |
105 | * XXX: Document all these weird requirements for gss mechanism | |
106 | * wrap/unwrap functions. */ | |
107 | if (pad > blocksize) | |
108 | return -EINVAL; | |
109 | if (buf->len > pad) | |
110 | buf->len -= pad; | |
111 | else | |
112 | return -EINVAL; | |
113 | return 0; | |
114 | } | |
115 | ||
934a95aa KC |
116 | void |
117 | gss_krb5_make_confounder(char *p, u32 conflen) | |
14ae162c BF |
118 | { |
119 | static u64 i = 0; | |
120 | u64 *q = (u64 *)p; | |
121 | ||
122 | /* rfc1964 claims this should be "random". But all that's really | |
123 | * necessary is that it be unique. And not even that is necessary in | |
124 | * our case since our "gssapi" implementation exists only to support | |
125 | * rpcsec_gss, so we know that the only buffers we will ever encrypt | |
126 | * already begin with a unique sequence number. Just to hedge my bets | |
127 | * I'll make a half-hearted attempt at something unique, but ensuring | |
128 | * uniqueness would mean worrying about atomicity and rollover, and I | |
129 | * don't care enough. */ | |
130 | ||
863a2488 KC |
131 | /* initialize to random value */ |
132 | if (i == 0) { | |
c86d2dde AM |
133 | i = prandom_u32(); |
134 | i = (i << 32) | prandom_u32(); | |
863a2488 KC |
135 | } |
136 | ||
137 | switch (conflen) { | |
138 | case 16: | |
139 | *q++ = i++; | |
140 | /* fall through */ | |
141 | case 8: | |
142 | *q++ = i++; | |
143 | break; | |
144 | default: | |
145 | BUG(); | |
146 | } | |
14ae162c BF |
147 | } |
148 | ||
149 | /* Assumptions: the head and tail of inbuf are ours to play with. | |
150 | * The pages, however, may be real pages in the page cache and we replace | |
151 | * them with scratch pages from **pages before writing to them. */ | |
152 | /* XXX: obviously the above should be documentation of wrap interface, | |
153 | * and shouldn't be in this kerberos-specific file. */ | |
154 | ||
155 | /* XXX factor out common code with seal/unseal. */ | |
156 | ||
1ac3719a KC |
157 | static u32 |
158 | gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset, | |
14ae162c BF |
159 | struct xdr_buf *buf, struct page **pages) |
160 | { | |
81d4a433 KC |
161 | char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; |
162 | struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), | |
163 | .data = cksumdata}; | |
14ae162c | 164 | int blocksize = 0, plainlen; |
d00953a5 | 165 | unsigned char *ptr, *msg_start; |
14ae162c BF |
166 | s32 now; |
167 | int headlen; | |
168 | struct page **tmp_pages; | |
eaa82edf | 169 | u32 seq_send; |
e1f6c07b | 170 | u8 *cksumkey; |
5af46547 | 171 | u32 conflen = kctx->gk5e->conflen; |
14ae162c | 172 | |
81d4a433 | 173 | dprintk("RPC: %s\n", __func__); |
14ae162c BF |
174 | |
175 | now = get_seconds(); | |
176 | ||
3b5cf20c | 177 | blocksize = crypto_skcipher_blocksize(kctx->enc); |
14ae162c BF |
178 | gss_krb5_add_padding(buf, offset, blocksize); |
179 | BUG_ON((buf->len - offset) % blocksize); | |
5af46547 | 180 | plainlen = conflen + buf->len - offset; |
14ae162c | 181 | |
81d4a433 KC |
182 | headlen = g_token_size(&kctx->mech_used, |
183 | GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength + plainlen) - | |
184 | (buf->len - offset); | |
14ae162c BF |
185 | |
186 | ptr = buf->head[0].iov_base + offset; | |
187 | /* shift data to make room for header. */ | |
725f2865 KC |
188 | xdr_extend_head(buf, offset, headlen); |
189 | ||
14ae162c | 190 | /* XXX Would be cleverer to encrypt while copying. */ |
14ae162c BF |
191 | BUG_ON((buf->len - offset - headlen) % blocksize); |
192 | ||
d00953a5 | 193 | g_make_token_header(&kctx->mech_used, |
81d4a433 KC |
194 | GSS_KRB5_TOK_HDR_LEN + |
195 | kctx->gk5e->cksumlength + plainlen, &ptr); | |
14ae162c BF |
196 | |
197 | ||
d00953a5 KC |
198 | /* ptr now at header described in rfc 1964, section 1.2.1: */ |
199 | ptr[0] = (unsigned char) ((KG_TOK_WRAP_MSG >> 8) & 0xff); | |
200 | ptr[1] = (unsigned char) (KG_TOK_WRAP_MSG & 0xff); | |
14ae162c | 201 | |
81d4a433 | 202 | msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength; |
14ae162c | 203 | |
b36e9c44 JL |
204 | /* |
205 | * signalg and sealalg are stored as if they were converted from LE | |
206 | * to host endian, even though they're opaque pairs of bytes according | |
207 | * to the RFC. | |
208 | */ | |
209 | *(__le16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg); | |
210 | *(__le16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg); | |
211 | ptr[6] = 0xff; | |
212 | ptr[7] = 0xff; | |
14ae162c | 213 | |
5af46547 | 214 | gss_krb5_make_confounder(msg_start, conflen); |
14ae162c | 215 | |
e1f6c07b KC |
216 | if (kctx->gk5e->keyed_cksum) |
217 | cksumkey = kctx->cksum; | |
218 | else | |
219 | cksumkey = NULL; | |
220 | ||
14ae162c BF |
221 | /* XXXJBF: UGH!: */ |
222 | tmp_pages = buf->pages; | |
223 | buf->pages = pages; | |
5af46547 | 224 | if (make_checksum(kctx, ptr, 8, buf, offset + headlen - conflen, |
8b237076 | 225 | cksumkey, KG_USAGE_SEAL, &md5cksum)) |
39a21dd1 | 226 | return GSS_S_FAILURE; |
14ae162c BF |
227 | buf->pages = tmp_pages; |
228 | ||
e1f6c07b | 229 | memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len); |
14ae162c | 230 | |
eaa82edf BF |
231 | spin_lock(&krb5_seq_lock); |
232 | seq_send = kctx->seq_send++; | |
233 | spin_unlock(&krb5_seq_lock); | |
234 | ||
14ae162c BF |
235 | /* XXX would probably be more efficient to compute checksum |
236 | * and encrypt at the same time: */ | |
1dbd9029 | 237 | if ((krb5_make_seq_num(kctx, kctx->seq, kctx->initiate ? 0 : 0xff, |
d00953a5 | 238 | seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8))) |
39a21dd1 | 239 | return GSS_S_FAILURE; |
14ae162c | 240 | |
fffdaef2 | 241 | if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) { |
3b5cf20c | 242 | struct crypto_skcipher *cipher; |
fffdaef2 | 243 | int err; |
3b5cf20c HX |
244 | cipher = crypto_alloc_skcipher(kctx->gk5e->encrypt_name, 0, |
245 | CRYPTO_ALG_ASYNC); | |
fffdaef2 KC |
246 | if (IS_ERR(cipher)) |
247 | return GSS_S_FAILURE; | |
248 | ||
249 | krb5_rc4_setup_enc_key(kctx, cipher, seq_send); | |
250 | ||
251 | err = gss_encrypt_xdr_buf(cipher, buf, | |
252 | offset + headlen - conflen, pages); | |
3b5cf20c | 253 | crypto_free_skcipher(cipher); |
fffdaef2 KC |
254 | if (err) |
255 | return GSS_S_FAILURE; | |
256 | } else { | |
257 | if (gss_encrypt_xdr_buf(kctx->enc, buf, | |
258 | offset + headlen - conflen, pages)) | |
259 | return GSS_S_FAILURE; | |
260 | } | |
14ae162c | 261 | |
94efa934 | 262 | return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; |
14ae162c BF |
263 | } |
264 | ||
1ac3719a KC |
265 | static u32 |
266 | gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) | |
14ae162c | 267 | { |
14ae162c BF |
268 | int signalg; |
269 | int sealalg; | |
81d4a433 KC |
270 | char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; |
271 | struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), | |
272 | .data = cksumdata}; | |
14ae162c BF |
273 | s32 now; |
274 | int direction; | |
275 | s32 seqnum; | |
276 | unsigned char *ptr; | |
277 | int bodysize; | |
14ae162c BF |
278 | void *data_start, *orig_start; |
279 | int data_len; | |
280 | int blocksize; | |
5af46547 | 281 | u32 conflen = kctx->gk5e->conflen; |
81d4a433 | 282 | int crypt_offset; |
e1f6c07b | 283 | u8 *cksumkey; |
14ae162c | 284 | |
8885cb36 | 285 | dprintk("RPC: gss_unwrap_kerberos\n"); |
14ae162c BF |
286 | |
287 | ptr = (u8 *)buf->head[0].iov_base + offset; | |
288 | if (g_verify_token_header(&kctx->mech_used, &bodysize, &ptr, | |
289 | buf->len - offset)) | |
39a21dd1 | 290 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c | 291 | |
d00953a5 KC |
292 | if ((ptr[0] != ((KG_TOK_WRAP_MSG >> 8) & 0xff)) || |
293 | (ptr[1] != (KG_TOK_WRAP_MSG & 0xff))) | |
39a21dd1 | 294 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c BF |
295 | |
296 | /* XXX sanity-check bodysize?? */ | |
297 | ||
298 | /* get the sign and seal algorithms */ | |
299 | ||
d00953a5 | 300 | signalg = ptr[2] + (ptr[3] << 8); |
81d4a433 | 301 | if (signalg != kctx->gk5e->signalg) |
39a21dd1 | 302 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c | 303 | |
d00953a5 | 304 | sealalg = ptr[4] + (ptr[5] << 8); |
81d4a433 | 305 | if (sealalg != kctx->gk5e->sealalg) |
39a21dd1 | 306 | return GSS_S_DEFECTIVE_TOKEN; |
94efa934 | 307 | |
d00953a5 | 308 | if ((ptr[6] != 0xff) || (ptr[7] != 0xff)) |
39a21dd1 | 309 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c | 310 | |
81d4a433 KC |
311 | /* |
312 | * Data starts after token header and checksum. ptr points | |
313 | * to the beginning of the token header | |
314 | */ | |
315 | crypt_offset = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) - | |
316 | (unsigned char *)buf->head[0].iov_base; | |
fffdaef2 KC |
317 | |
318 | /* | |
319 | * Need plaintext seqnum to derive encryption key for arcfour-hmac | |
320 | */ | |
321 | if (krb5_get_seq_num(kctx, ptr + GSS_KRB5_TOK_HDR_LEN, | |
322 | ptr + 8, &direction, &seqnum)) | |
323 | return GSS_S_BAD_SIG; | |
324 | ||
325 | if ((kctx->initiate && direction != 0xff) || | |
326 | (!kctx->initiate && direction != 0)) | |
327 | return GSS_S_BAD_SIG; | |
328 | ||
329 | if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) { | |
3b5cf20c | 330 | struct crypto_skcipher *cipher; |
fffdaef2 KC |
331 | int err; |
332 | ||
3b5cf20c HX |
333 | cipher = crypto_alloc_skcipher(kctx->gk5e->encrypt_name, 0, |
334 | CRYPTO_ALG_ASYNC); | |
fffdaef2 KC |
335 | if (IS_ERR(cipher)) |
336 | return GSS_S_FAILURE; | |
337 | ||
338 | krb5_rc4_setup_enc_key(kctx, cipher, seqnum); | |
339 | ||
340 | err = gss_decrypt_xdr_buf(cipher, buf, crypt_offset); | |
3b5cf20c | 341 | crypto_free_skcipher(cipher); |
fffdaef2 KC |
342 | if (err) |
343 | return GSS_S_DEFECTIVE_TOKEN; | |
344 | } else { | |
345 | if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset)) | |
346 | return GSS_S_DEFECTIVE_TOKEN; | |
347 | } | |
14ae162c | 348 | |
e1f6c07b KC |
349 | if (kctx->gk5e->keyed_cksum) |
350 | cksumkey = kctx->cksum; | |
351 | else | |
352 | cksumkey = NULL; | |
5eb064f9 | 353 | |
e1f6c07b | 354 | if (make_checksum(kctx, ptr, 8, buf, crypt_offset, |
8b237076 | 355 | cksumkey, KG_USAGE_SEAL, &md5cksum)) |
39a21dd1 | 356 | return GSS_S_FAILURE; |
14ae162c | 357 | |
e1f6c07b KC |
358 | if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN, |
359 | kctx->gk5e->cksumlength)) | |
39a21dd1 | 360 | return GSS_S_BAD_SIG; |
14ae162c BF |
361 | |
362 | /* it got through unscathed. Make sure the context is unexpired */ | |
363 | ||
14ae162c BF |
364 | now = get_seconds(); |
365 | ||
14ae162c | 366 | if (now > kctx->endtime) |
39a21dd1 | 367 | return GSS_S_CONTEXT_EXPIRED; |
14ae162c BF |
368 | |
369 | /* do sequencing checks */ | |
370 | ||
14ae162c BF |
371 | /* Copy the data back to the right position. XXX: Would probably be |
372 | * better to copy and encrypt at the same time. */ | |
373 | ||
3b5cf20c | 374 | blocksize = crypto_skcipher_blocksize(kctx->enc); |
81d4a433 | 375 | data_start = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) + |
5af46547 | 376 | conflen; |
14ae162c BF |
377 | orig_start = buf->head[0].iov_base + offset; |
378 | data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start; | |
379 | memmove(orig_start, data_start, data_len); | |
380 | buf->head[0].iov_len -= (data_start - orig_start); | |
381 | buf->len -= (data_start - orig_start); | |
382 | ||
14ae162c | 383 | if (gss_krb5_remove_padding(buf, blocksize)) |
39a21dd1 | 384 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c | 385 | |
39a21dd1 | 386 | return GSS_S_COMPLETE; |
14ae162c | 387 | } |
1ac3719a | 388 | |
de9c17eb | 389 | /* |
c52226da BF |
390 | * We can shift data by up to LOCAL_BUF_LEN bytes in a pass. If we need |
391 | * to do more than that, we shift repeatedly. Kevin Coffman reports | |
392 | * seeing 28 bytes as the value used by Microsoft clients and servers | |
393 | * with AES, so this constant is chosen to allow handling 28 in one pass | |
394 | * without using too much stack space. | |
395 | * | |
396 | * If that proves to a problem perhaps we could use a more clever | |
397 | * algorithm. | |
de9c17eb | 398 | */ |
c52226da BF |
399 | #define LOCAL_BUF_LEN 32u |
400 | ||
401 | static void rotate_buf_a_little(struct xdr_buf *buf, unsigned int shift) | |
de9c17eb | 402 | { |
c52226da BF |
403 | char head[LOCAL_BUF_LEN]; |
404 | char tmp[LOCAL_BUF_LEN]; | |
405 | unsigned int this_len, i; | |
406 | ||
407 | BUG_ON(shift > LOCAL_BUF_LEN); | |
de9c17eb | 408 | |
c52226da BF |
409 | read_bytes_from_xdr_buf(buf, 0, head, shift); |
410 | for (i = 0; i + shift < buf->len; i += LOCAL_BUF_LEN) { | |
411 | this_len = min(LOCAL_BUF_LEN, buf->len - (i + shift)); | |
412 | read_bytes_from_xdr_buf(buf, i+shift, tmp, this_len); | |
413 | write_bytes_to_xdr_buf(buf, i, tmp, this_len); | |
414 | } | |
415 | write_bytes_to_xdr_buf(buf, buf->len - shift, head, shift); | |
416 | } | |
de9c17eb | 417 | |
c52226da BF |
418 | static void _rotate_left(struct xdr_buf *buf, unsigned int shift) |
419 | { | |
420 | int shifted = 0; | |
421 | int this_shift; | |
422 | ||
423 | shift %= buf->len; | |
424 | while (shifted < shift) { | |
425 | this_shift = min(shift - shifted, LOCAL_BUF_LEN); | |
426 | rotate_buf_a_little(buf, this_shift); | |
427 | shifted += this_shift; | |
428 | } | |
429 | } | |
430 | ||
431 | static void rotate_left(u32 base, struct xdr_buf *buf, unsigned int shift) | |
432 | { | |
433 | struct xdr_buf subbuf; | |
434 | ||
435 | xdr_buf_subsegment(buf, &subbuf, base, buf->len - base); | |
436 | _rotate_left(&subbuf, shift); | |
de9c17eb KC |
437 | } |
438 | ||
439 | static u32 | |
440 | gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset, | |
441 | struct xdr_buf *buf, struct page **pages) | |
442 | { | |
443 | int blocksize; | |
444 | u8 *ptr, *plainhdr; | |
445 | s32 now; | |
446 | u8 flags = 0x00; | |
b36e9c44 | 447 | __be16 *be16ptr; |
de9c17eb KC |
448 | __be64 *be64ptr; |
449 | u32 err; | |
450 | ||
451 | dprintk("RPC: %s\n", __func__); | |
452 | ||
453 | if (kctx->gk5e->encrypt_v2 == NULL) | |
454 | return GSS_S_FAILURE; | |
455 | ||
456 | /* make room for gss token header */ | |
457 | if (xdr_extend_head(buf, offset, GSS_KRB5_TOK_HDR_LEN)) | |
458 | return GSS_S_FAILURE; | |
459 | ||
460 | /* construct gss token header */ | |
461 | ptr = plainhdr = buf->head[0].iov_base + offset; | |
462 | *ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff); | |
463 | *ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff); | |
464 | ||
465 | if ((kctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0) | |
466 | flags |= KG2_TOKEN_FLAG_SENTBYACCEPTOR; | |
467 | if ((kctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) != 0) | |
468 | flags |= KG2_TOKEN_FLAG_ACCEPTORSUBKEY; | |
469 | /* We always do confidentiality in wrap tokens */ | |
470 | flags |= KG2_TOKEN_FLAG_SEALED; | |
471 | ||
472 | *ptr++ = flags; | |
473 | *ptr++ = 0xff; | |
474 | be16ptr = (__be16 *)ptr; | |
475 | ||
3b5cf20c | 476 | blocksize = crypto_skcipher_blocksize(kctx->acceptor_enc); |
b36e9c44 | 477 | *be16ptr++ = 0; |
de9c17eb | 478 | /* "inner" token header always uses 0 for RRC */ |
b36e9c44 | 479 | *be16ptr++ = 0; |
de9c17eb KC |
480 | |
481 | be64ptr = (__be64 *)be16ptr; | |
482 | spin_lock(&krb5_seq_lock); | |
483 | *be64ptr = cpu_to_be64(kctx->seq_send64++); | |
484 | spin_unlock(&krb5_seq_lock); | |
485 | ||
ec25422c | 486 | err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, pages); |
de9c17eb KC |
487 | if (err) |
488 | return err; | |
489 | ||
490 | now = get_seconds(); | |
491 | return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; | |
492 | } | |
493 | ||
494 | static u32 | |
495 | gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) | |
496 | { | |
497 | s32 now; | |
de9c17eb KC |
498 | u8 *ptr; |
499 | u8 flags = 0x00; | |
500 | u16 ec, rrc; | |
501 | int err; | |
502 | u32 headskip, tailskip; | |
503 | u8 decrypted_hdr[GSS_KRB5_TOK_HDR_LEN]; | |
504 | unsigned int movelen; | |
505 | ||
506 | ||
507 | dprintk("RPC: %s\n", __func__); | |
508 | ||
509 | if (kctx->gk5e->decrypt_v2 == NULL) | |
510 | return GSS_S_FAILURE; | |
511 | ||
512 | ptr = buf->head[0].iov_base + offset; | |
513 | ||
514 | if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_WRAP) | |
515 | return GSS_S_DEFECTIVE_TOKEN; | |
516 | ||
517 | flags = ptr[2]; | |
518 | if ((!kctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) || | |
519 | (kctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR))) | |
520 | return GSS_S_BAD_SIG; | |
521 | ||
522 | if ((flags & KG2_TOKEN_FLAG_SEALED) == 0) { | |
523 | dprintk("%s: token missing expected sealed flag\n", __func__); | |
524 | return GSS_S_DEFECTIVE_TOKEN; | |
525 | } | |
526 | ||
527 | if (ptr[3] != 0xff) | |
528 | return GSS_S_DEFECTIVE_TOKEN; | |
529 | ||
530 | ec = be16_to_cpup((__be16 *)(ptr + 4)); | |
531 | rrc = be16_to_cpup((__be16 *)(ptr + 6)); | |
532 | ||
5d6baef9 BF |
533 | /* |
534 | * NOTE: the sequence number at ptr + 8 is skipped, rpcsec_gss | |
535 | * doesn't want it checked; see page 6 of rfc 2203. | |
536 | */ | |
de9c17eb | 537 | |
c52226da BF |
538 | if (rrc != 0) |
539 | rotate_left(offset + 16, buf, rrc); | |
de9c17eb KC |
540 | |
541 | err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf, | |
542 | &headskip, &tailskip); | |
543 | if (err) | |
544 | return GSS_S_FAILURE; | |
545 | ||
546 | /* | |
547 | * Retrieve the decrypted gss token header and verify | |
548 | * it against the original | |
549 | */ | |
550 | err = read_bytes_from_xdr_buf(buf, | |
551 | buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip, | |
552 | decrypted_hdr, GSS_KRB5_TOK_HDR_LEN); | |
553 | if (err) { | |
554 | dprintk("%s: error %u getting decrypted_hdr\n", __func__, err); | |
555 | return GSS_S_FAILURE; | |
556 | } | |
557 | if (memcmp(ptr, decrypted_hdr, 6) | |
558 | || memcmp(ptr + 8, decrypted_hdr + 8, 8)) { | |
559 | dprintk("%s: token hdr, plaintext hdr mismatch!\n", __func__); | |
560 | return GSS_S_FAILURE; | |
561 | } | |
562 | ||
563 | /* do sequencing checks */ | |
564 | ||
565 | /* it got through unscathed. Make sure the context is unexpired */ | |
566 | now = get_seconds(); | |
567 | if (now > kctx->endtime) | |
568 | return GSS_S_CONTEXT_EXPIRED; | |
569 | ||
570 | /* | |
571 | * Move the head data back to the right position in xdr_buf. | |
572 | * We ignore any "ec" data since it might be in the head or | |
573 | * the tail, and we really don't need to deal with it. | |
574 | * Note that buf->head[0].iov_len may indicate the available | |
575 | * head buffer space rather than that actually occupied. | |
576 | */ | |
577 | movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len); | |
578 | movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip; | |
579 | BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen > | |
580 | buf->head[0].iov_len); | |
581 | memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen); | |
582 | buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip; | |
583 | buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip; | |
584 | ||
cf4c024b JL |
585 | /* Trim off the trailing "extra count" and checksum blob */ |
586 | xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip); | |
de9c17eb KC |
587 | return GSS_S_COMPLETE; |
588 | } | |
589 | ||
1ac3719a KC |
590 | u32 |
591 | gss_wrap_kerberos(struct gss_ctx *gctx, int offset, | |
592 | struct xdr_buf *buf, struct page **pages) | |
593 | { | |
594 | struct krb5_ctx *kctx = gctx->internal_ctx_id; | |
595 | ||
596 | switch (kctx->enctype) { | |
597 | default: | |
598 | BUG(); | |
599 | case ENCTYPE_DES_CBC_RAW: | |
958142e9 | 600 | case ENCTYPE_DES3_CBC_RAW: |
fffdaef2 | 601 | case ENCTYPE_ARCFOUR_HMAC: |
1ac3719a | 602 | return gss_wrap_kerberos_v1(kctx, offset, buf, pages); |
de9c17eb KC |
603 | case ENCTYPE_AES128_CTS_HMAC_SHA1_96: |
604 | case ENCTYPE_AES256_CTS_HMAC_SHA1_96: | |
605 | return gss_wrap_kerberos_v2(kctx, offset, buf, pages); | |
1ac3719a KC |
606 | } |
607 | } | |
608 | ||
609 | u32 | |
610 | gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf) | |
611 | { | |
612 | struct krb5_ctx *kctx = gctx->internal_ctx_id; | |
613 | ||
614 | switch (kctx->enctype) { | |
615 | default: | |
616 | BUG(); | |
617 | case ENCTYPE_DES_CBC_RAW: | |
958142e9 | 618 | case ENCTYPE_DES3_CBC_RAW: |
fffdaef2 | 619 | case ENCTYPE_ARCFOUR_HMAC: |
1ac3719a | 620 | return gss_unwrap_kerberos_v1(kctx, offset, buf); |
de9c17eb KC |
621 | case ENCTYPE_AES128_CTS_HMAC_SHA1_96: |
622 | case ENCTYPE_AES256_CTS_HMAC_SHA1_96: | |
623 | return gss_unwrap_kerberos_v2(kctx, offset, buf); | |
1ac3719a KC |
624 | } |
625 | } | |
626 |