Commit | Line | Data |
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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 | ||
14ae162c | 31 | #include <linux/types.h> |
14ae162c BF |
32 | #include <linux/jiffies.h> |
33 | #include <linux/sunrpc/gss_krb5.h> | |
34 | #include <linux/random.h> | |
35 | #include <linux/pagemap.h> | |
14ae162c BF |
36 | #include <linux/crypto.h> |
37 | ||
38 | #ifdef RPC_DEBUG | |
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) |
14ae162c | 82 | >>PAGE_CACHE_SHIFT; |
67f97d83 | 83 | unsigned int offset = (buf->page_base + len - 1) |
14ae162c | 84 | & (PAGE_CACHE_SIZE - 1); |
87d918d6 | 85 | ptr = kmap_atomic(buf->pages[last], KM_USER0); |
14ae162c | 86 | pad = *(ptr + offset); |
87d918d6 | 87 | kunmap_atomic(ptr, KM_USER0); |
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) { | |
133 | i = random32(); | |
134 | i = (i << 32) | random32(); | |
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 | ||
378c6697 | 177 | blocksize = crypto_blkcipher_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 | |
81d4a433 | 204 | *(__be16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg); |
d00953a5 | 205 | memset(ptr + 4, 0xff, 4); |
81d4a433 | 206 | *(__be16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg); |
14ae162c | 207 | |
5af46547 | 208 | gss_krb5_make_confounder(msg_start, conflen); |
14ae162c | 209 | |
e1f6c07b KC |
210 | if (kctx->gk5e->keyed_cksum) |
211 | cksumkey = kctx->cksum; | |
212 | else | |
213 | cksumkey = NULL; | |
214 | ||
14ae162c BF |
215 | /* XXXJBF: UGH!: */ |
216 | tmp_pages = buf->pages; | |
217 | buf->pages = pages; | |
5af46547 | 218 | if (make_checksum(kctx, ptr, 8, buf, offset + headlen - conflen, |
8b237076 | 219 | cksumkey, KG_USAGE_SEAL, &md5cksum)) |
39a21dd1 | 220 | return GSS_S_FAILURE; |
14ae162c BF |
221 | buf->pages = tmp_pages; |
222 | ||
e1f6c07b | 223 | memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len); |
14ae162c | 224 | |
eaa82edf BF |
225 | spin_lock(&krb5_seq_lock); |
226 | seq_send = kctx->seq_send++; | |
227 | spin_unlock(&krb5_seq_lock); | |
228 | ||
14ae162c BF |
229 | /* XXX would probably be more efficient to compute checksum |
230 | * and encrypt at the same time: */ | |
1dbd9029 | 231 | if ((krb5_make_seq_num(kctx, kctx->seq, kctx->initiate ? 0 : 0xff, |
d00953a5 | 232 | seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8))) |
39a21dd1 | 233 | return GSS_S_FAILURE; |
14ae162c | 234 | |
fffdaef2 KC |
235 | if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) { |
236 | struct crypto_blkcipher *cipher; | |
237 | int err; | |
238 | cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0, | |
239 | CRYPTO_ALG_ASYNC); | |
240 | if (IS_ERR(cipher)) | |
241 | return GSS_S_FAILURE; | |
242 | ||
243 | krb5_rc4_setup_enc_key(kctx, cipher, seq_send); | |
244 | ||
245 | err = gss_encrypt_xdr_buf(cipher, buf, | |
246 | offset + headlen - conflen, pages); | |
247 | crypto_free_blkcipher(cipher); | |
248 | if (err) | |
249 | return GSS_S_FAILURE; | |
250 | } else { | |
251 | if (gss_encrypt_xdr_buf(kctx->enc, buf, | |
252 | offset + headlen - conflen, pages)) | |
253 | return GSS_S_FAILURE; | |
254 | } | |
14ae162c | 255 | |
94efa934 | 256 | return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; |
14ae162c BF |
257 | } |
258 | ||
1ac3719a KC |
259 | static u32 |
260 | gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) | |
14ae162c | 261 | { |
14ae162c BF |
262 | int signalg; |
263 | int sealalg; | |
81d4a433 KC |
264 | char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; |
265 | struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), | |
266 | .data = cksumdata}; | |
14ae162c BF |
267 | s32 now; |
268 | int direction; | |
269 | s32 seqnum; | |
270 | unsigned char *ptr; | |
271 | int bodysize; | |
14ae162c BF |
272 | void *data_start, *orig_start; |
273 | int data_len; | |
274 | int blocksize; | |
5af46547 | 275 | u32 conflen = kctx->gk5e->conflen; |
81d4a433 | 276 | int crypt_offset; |
e1f6c07b | 277 | u8 *cksumkey; |
14ae162c | 278 | |
8885cb36 | 279 | dprintk("RPC: gss_unwrap_kerberos\n"); |
14ae162c BF |
280 | |
281 | ptr = (u8 *)buf->head[0].iov_base + offset; | |
282 | if (g_verify_token_header(&kctx->mech_used, &bodysize, &ptr, | |
283 | buf->len - offset)) | |
39a21dd1 | 284 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c | 285 | |
d00953a5 KC |
286 | if ((ptr[0] != ((KG_TOK_WRAP_MSG >> 8) & 0xff)) || |
287 | (ptr[1] != (KG_TOK_WRAP_MSG & 0xff))) | |
39a21dd1 | 288 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c BF |
289 | |
290 | /* XXX sanity-check bodysize?? */ | |
291 | ||
292 | /* get the sign and seal algorithms */ | |
293 | ||
d00953a5 | 294 | signalg = ptr[2] + (ptr[3] << 8); |
81d4a433 | 295 | if (signalg != kctx->gk5e->signalg) |
39a21dd1 | 296 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c | 297 | |
d00953a5 | 298 | sealalg = ptr[4] + (ptr[5] << 8); |
81d4a433 | 299 | if (sealalg != kctx->gk5e->sealalg) |
39a21dd1 | 300 | return GSS_S_DEFECTIVE_TOKEN; |
94efa934 | 301 | |
d00953a5 | 302 | if ((ptr[6] != 0xff) || (ptr[7] != 0xff)) |
39a21dd1 | 303 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c | 304 | |
81d4a433 KC |
305 | /* |
306 | * Data starts after token header and checksum. ptr points | |
307 | * to the beginning of the token header | |
308 | */ | |
309 | crypt_offset = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) - | |
310 | (unsigned char *)buf->head[0].iov_base; | |
fffdaef2 KC |
311 | |
312 | /* | |
313 | * Need plaintext seqnum to derive encryption key for arcfour-hmac | |
314 | */ | |
315 | if (krb5_get_seq_num(kctx, ptr + GSS_KRB5_TOK_HDR_LEN, | |
316 | ptr + 8, &direction, &seqnum)) | |
317 | return GSS_S_BAD_SIG; | |
318 | ||
319 | if ((kctx->initiate && direction != 0xff) || | |
320 | (!kctx->initiate && direction != 0)) | |
321 | return GSS_S_BAD_SIG; | |
322 | ||
323 | if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) { | |
324 | struct crypto_blkcipher *cipher; | |
325 | int err; | |
326 | ||
327 | cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0, | |
328 | CRYPTO_ALG_ASYNC); | |
329 | if (IS_ERR(cipher)) | |
330 | return GSS_S_FAILURE; | |
331 | ||
332 | krb5_rc4_setup_enc_key(kctx, cipher, seqnum); | |
333 | ||
334 | err = gss_decrypt_xdr_buf(cipher, buf, crypt_offset); | |
335 | crypto_free_blkcipher(cipher); | |
336 | if (err) | |
337 | return GSS_S_DEFECTIVE_TOKEN; | |
338 | } else { | |
339 | if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset)) | |
340 | return GSS_S_DEFECTIVE_TOKEN; | |
341 | } | |
14ae162c | 342 | |
e1f6c07b KC |
343 | if (kctx->gk5e->keyed_cksum) |
344 | cksumkey = kctx->cksum; | |
345 | else | |
346 | cksumkey = NULL; | |
5eb064f9 | 347 | |
e1f6c07b | 348 | if (make_checksum(kctx, ptr, 8, buf, crypt_offset, |
8b237076 | 349 | cksumkey, KG_USAGE_SEAL, &md5cksum)) |
39a21dd1 | 350 | return GSS_S_FAILURE; |
14ae162c | 351 | |
e1f6c07b KC |
352 | if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN, |
353 | kctx->gk5e->cksumlength)) | |
39a21dd1 | 354 | return GSS_S_BAD_SIG; |
14ae162c BF |
355 | |
356 | /* it got through unscathed. Make sure the context is unexpired */ | |
357 | ||
14ae162c BF |
358 | now = get_seconds(); |
359 | ||
14ae162c | 360 | if (now > kctx->endtime) |
39a21dd1 | 361 | return GSS_S_CONTEXT_EXPIRED; |
14ae162c BF |
362 | |
363 | /* do sequencing checks */ | |
364 | ||
14ae162c BF |
365 | /* Copy the data back to the right position. XXX: Would probably be |
366 | * better to copy and encrypt at the same time. */ | |
367 | ||
378c6697 | 368 | blocksize = crypto_blkcipher_blocksize(kctx->enc); |
81d4a433 | 369 | data_start = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) + |
5af46547 | 370 | conflen; |
14ae162c BF |
371 | orig_start = buf->head[0].iov_base + offset; |
372 | data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start; | |
373 | memmove(orig_start, data_start, data_len); | |
374 | buf->head[0].iov_len -= (data_start - orig_start); | |
375 | buf->len -= (data_start - orig_start); | |
376 | ||
14ae162c | 377 | if (gss_krb5_remove_padding(buf, blocksize)) |
39a21dd1 | 378 | return GSS_S_DEFECTIVE_TOKEN; |
14ae162c | 379 | |
39a21dd1 | 380 | return GSS_S_COMPLETE; |
14ae162c | 381 | } |
1ac3719a | 382 | |
de9c17eb KC |
383 | /* |
384 | * We cannot currently handle tokens with rotated data. We need a | |
385 | * generalized routine to rotate the data in place. It is anticipated | |
386 | * that we won't encounter rotated data in the general case. | |
387 | */ | |
388 | static u32 | |
389 | rotate_left(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf, u16 rrc) | |
390 | { | |
391 | unsigned int realrrc = rrc % (buf->len - offset - GSS_KRB5_TOK_HDR_LEN); | |
392 | ||
393 | if (realrrc == 0) | |
394 | return 0; | |
395 | ||
396 | dprintk("%s: cannot process token with rotated data: " | |
397 | "rrc %u, realrrc %u\n", __func__, rrc, realrrc); | |
398 | return 1; | |
399 | } | |
400 | ||
401 | static u32 | |
402 | gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset, | |
403 | struct xdr_buf *buf, struct page **pages) | |
404 | { | |
405 | int blocksize; | |
406 | u8 *ptr, *plainhdr; | |
407 | s32 now; | |
408 | u8 flags = 0x00; | |
409 | __be16 *be16ptr, ec = 0; | |
410 | __be64 *be64ptr; | |
411 | u32 err; | |
412 | ||
413 | dprintk("RPC: %s\n", __func__); | |
414 | ||
415 | if (kctx->gk5e->encrypt_v2 == NULL) | |
416 | return GSS_S_FAILURE; | |
417 | ||
418 | /* make room for gss token header */ | |
419 | if (xdr_extend_head(buf, offset, GSS_KRB5_TOK_HDR_LEN)) | |
420 | return GSS_S_FAILURE; | |
421 | ||
422 | /* construct gss token header */ | |
423 | ptr = plainhdr = buf->head[0].iov_base + offset; | |
424 | *ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff); | |
425 | *ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff); | |
426 | ||
427 | if ((kctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0) | |
428 | flags |= KG2_TOKEN_FLAG_SENTBYACCEPTOR; | |
429 | if ((kctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) != 0) | |
430 | flags |= KG2_TOKEN_FLAG_ACCEPTORSUBKEY; | |
431 | /* We always do confidentiality in wrap tokens */ | |
432 | flags |= KG2_TOKEN_FLAG_SEALED; | |
433 | ||
434 | *ptr++ = flags; | |
435 | *ptr++ = 0xff; | |
436 | be16ptr = (__be16 *)ptr; | |
437 | ||
438 | blocksize = crypto_blkcipher_blocksize(kctx->acceptor_enc); | |
439 | *be16ptr++ = cpu_to_be16(ec); | |
440 | /* "inner" token header always uses 0 for RRC */ | |
441 | *be16ptr++ = cpu_to_be16(0); | |
442 | ||
443 | be64ptr = (__be64 *)be16ptr; | |
444 | spin_lock(&krb5_seq_lock); | |
445 | *be64ptr = cpu_to_be64(kctx->seq_send64++); | |
446 | spin_unlock(&krb5_seq_lock); | |
447 | ||
448 | err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, ec, pages); | |
449 | if (err) | |
450 | return err; | |
451 | ||
452 | now = get_seconds(); | |
453 | return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; | |
454 | } | |
455 | ||
456 | static u32 | |
457 | gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) | |
458 | { | |
459 | s32 now; | |
460 | u64 seqnum; | |
461 | u8 *ptr; | |
462 | u8 flags = 0x00; | |
463 | u16 ec, rrc; | |
464 | int err; | |
465 | u32 headskip, tailskip; | |
466 | u8 decrypted_hdr[GSS_KRB5_TOK_HDR_LEN]; | |
467 | unsigned int movelen; | |
468 | ||
469 | ||
470 | dprintk("RPC: %s\n", __func__); | |
471 | ||
472 | if (kctx->gk5e->decrypt_v2 == NULL) | |
473 | return GSS_S_FAILURE; | |
474 | ||
475 | ptr = buf->head[0].iov_base + offset; | |
476 | ||
477 | if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_WRAP) | |
478 | return GSS_S_DEFECTIVE_TOKEN; | |
479 | ||
480 | flags = ptr[2]; | |
481 | if ((!kctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) || | |
482 | (kctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR))) | |
483 | return GSS_S_BAD_SIG; | |
484 | ||
485 | if ((flags & KG2_TOKEN_FLAG_SEALED) == 0) { | |
486 | dprintk("%s: token missing expected sealed flag\n", __func__); | |
487 | return GSS_S_DEFECTIVE_TOKEN; | |
488 | } | |
489 | ||
490 | if (ptr[3] != 0xff) | |
491 | return GSS_S_DEFECTIVE_TOKEN; | |
492 | ||
493 | ec = be16_to_cpup((__be16 *)(ptr + 4)); | |
494 | rrc = be16_to_cpup((__be16 *)(ptr + 6)); | |
495 | ||
496 | seqnum = be64_to_cpup((__be64 *)(ptr + 8)); | |
497 | ||
498 | if (rrc != 0) { | |
499 | err = rotate_left(kctx, offset, buf, rrc); | |
500 | if (err) | |
501 | return GSS_S_FAILURE; | |
502 | } | |
503 | ||
504 | err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf, | |
505 | &headskip, &tailskip); | |
506 | if (err) | |
507 | return GSS_S_FAILURE; | |
508 | ||
509 | /* | |
510 | * Retrieve the decrypted gss token header and verify | |
511 | * it against the original | |
512 | */ | |
513 | err = read_bytes_from_xdr_buf(buf, | |
514 | buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip, | |
515 | decrypted_hdr, GSS_KRB5_TOK_HDR_LEN); | |
516 | if (err) { | |
517 | dprintk("%s: error %u getting decrypted_hdr\n", __func__, err); | |
518 | return GSS_S_FAILURE; | |
519 | } | |
520 | if (memcmp(ptr, decrypted_hdr, 6) | |
521 | || memcmp(ptr + 8, decrypted_hdr + 8, 8)) { | |
522 | dprintk("%s: token hdr, plaintext hdr mismatch!\n", __func__); | |
523 | return GSS_S_FAILURE; | |
524 | } | |
525 | ||
526 | /* do sequencing checks */ | |
527 | ||
528 | /* it got through unscathed. Make sure the context is unexpired */ | |
529 | now = get_seconds(); | |
530 | if (now > kctx->endtime) | |
531 | return GSS_S_CONTEXT_EXPIRED; | |
532 | ||
533 | /* | |
534 | * Move the head data back to the right position in xdr_buf. | |
535 | * We ignore any "ec" data since it might be in the head or | |
536 | * the tail, and we really don't need to deal with it. | |
537 | * Note that buf->head[0].iov_len may indicate the available | |
538 | * head buffer space rather than that actually occupied. | |
539 | */ | |
540 | movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len); | |
541 | movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip; | |
542 | BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen > | |
543 | buf->head[0].iov_len); | |
544 | memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen); | |
545 | buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip; | |
546 | buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip; | |
547 | ||
548 | return GSS_S_COMPLETE; | |
549 | } | |
550 | ||
1ac3719a KC |
551 | u32 |
552 | gss_wrap_kerberos(struct gss_ctx *gctx, int offset, | |
553 | struct xdr_buf *buf, struct page **pages) | |
554 | { | |
555 | struct krb5_ctx *kctx = gctx->internal_ctx_id; | |
556 | ||
557 | switch (kctx->enctype) { | |
558 | default: | |
559 | BUG(); | |
560 | case ENCTYPE_DES_CBC_RAW: | |
958142e9 | 561 | case ENCTYPE_DES3_CBC_RAW: |
fffdaef2 | 562 | case ENCTYPE_ARCFOUR_HMAC: |
1ac3719a | 563 | return gss_wrap_kerberos_v1(kctx, offset, buf, pages); |
de9c17eb KC |
564 | case ENCTYPE_AES128_CTS_HMAC_SHA1_96: |
565 | case ENCTYPE_AES256_CTS_HMAC_SHA1_96: | |
566 | return gss_wrap_kerberos_v2(kctx, offset, buf, pages); | |
1ac3719a KC |
567 | } |
568 | } | |
569 | ||
570 | u32 | |
571 | gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf) | |
572 | { | |
573 | struct krb5_ctx *kctx = gctx->internal_ctx_id; | |
574 | ||
575 | switch (kctx->enctype) { | |
576 | default: | |
577 | BUG(); | |
578 | case ENCTYPE_DES_CBC_RAW: | |
958142e9 | 579 | case ENCTYPE_DES3_CBC_RAW: |
fffdaef2 | 580 | case ENCTYPE_ARCFOUR_HMAC: |
1ac3719a | 581 | return gss_unwrap_kerberos_v1(kctx, offset, buf); |
de9c17eb KC |
582 | case ENCTYPE_AES128_CTS_HMAC_SHA1_96: |
583 | case ENCTYPE_AES256_CTS_HMAC_SHA1_96: | |
584 | return gss_unwrap_kerberos_v2(kctx, offset, buf); | |
1ac3719a KC |
585 | } |
586 | } | |
587 |