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1/*
2 * linux/net/sunrpc/gss_krb5_crypto.c
3 *
4 * Copyright (c) 2000-2008 The Regents of the University of Michigan.
5 * All rights reserved.
6 *
7 * Andy Adamson <andros@umich.edu>
8 * Bruce Fields <bfields@umich.edu>
9 */
10
11/*
12 * Copyright (C) 1998 by the FundsXpress, INC.
13 *
14 * All rights reserved.
15 *
16 * Export of this software from the United States of America may require
17 * a specific license from the United States Government. It is the
18 * responsibility of any person or organization contemplating export to
19 * obtain such a license before exporting.
20 *
21 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
22 * distribute this software and its documentation for any purpose and
23 * without fee is hereby granted, provided that the above copyright
24 * notice appear in all copies and that both that copyright notice and
25 * this permission notice appear in supporting documentation, and that
26 * the name of FundsXpress. not be used in advertising or publicity pertaining
27 * to distribution of the software without specific, written prior
28 * permission. FundsXpress makes no representations about the suitability of
29 * this software for any purpose. It is provided "as is" without express
30 * or implied warranty.
31 *
32 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
33 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
34 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
35 */
36
37#include <crypto/hash.h>
38#include <crypto/skcipher.h>
39#include <linux/err.h>
40#include <linux/types.h>
41#include <linux/mm.h>
42#include <linux/scatterlist.h>
43#include <linux/highmem.h>
44#include <linux/pagemap.h>
45#include <linux/random.h>
46#include <linux/sunrpc/gss_krb5.h>
47#include <linux/sunrpc/xdr.h>
48
49#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
50# define RPCDBG_FACILITY RPCDBG_AUTH
51#endif
52
53u32
54krb5_encrypt(
55 struct crypto_skcipher *tfm,
56 void * iv,
57 void * in,
58 void * out,
59 int length)
60{
61 u32 ret = -EINVAL;
62 struct scatterlist sg[1];
63 u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
64 SKCIPHER_REQUEST_ON_STACK(req, tfm);
65
66 if (length % crypto_skcipher_blocksize(tfm) != 0)
67 goto out;
68
69 if (crypto_skcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
70 dprintk("RPC: gss_k5encrypt: tfm iv size too large %d\n",
71 crypto_skcipher_ivsize(tfm));
72 goto out;
73 }
74
75 if (iv)
76 memcpy(local_iv, iv, crypto_skcipher_ivsize(tfm));
77
78 memcpy(out, in, length);
79 sg_init_one(sg, out, length);
80
81 skcipher_request_set_tfm(req, tfm);
82 skcipher_request_set_callback(req, 0, NULL, NULL);
83 skcipher_request_set_crypt(req, sg, sg, length, local_iv);
84
85 ret = crypto_skcipher_encrypt(req);
86 skcipher_request_zero(req);
87out:
88 dprintk("RPC: krb5_encrypt returns %d\n", ret);
89 return ret;
90}
91
92u32
93krb5_decrypt(
94 struct crypto_skcipher *tfm,
95 void * iv,
96 void * in,
97 void * out,
98 int length)
99{
100 u32 ret = -EINVAL;
101 struct scatterlist sg[1];
102 u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
103 SKCIPHER_REQUEST_ON_STACK(req, tfm);
104
105 if (length % crypto_skcipher_blocksize(tfm) != 0)
106 goto out;
107
108 if (crypto_skcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
109 dprintk("RPC: gss_k5decrypt: tfm iv size too large %d\n",
110 crypto_skcipher_ivsize(tfm));
111 goto out;
112 }
113 if (iv)
114 memcpy(local_iv,iv, crypto_skcipher_ivsize(tfm));
115
116 memcpy(out, in, length);
117 sg_init_one(sg, out, length);
118
119 skcipher_request_set_tfm(req, tfm);
120 skcipher_request_set_callback(req, 0, NULL, NULL);
121 skcipher_request_set_crypt(req, sg, sg, length, local_iv);
122
123 ret = crypto_skcipher_decrypt(req);
124 skcipher_request_zero(req);
125out:
126 dprintk("RPC: gss_k5decrypt returns %d\n",ret);
127 return ret;
128}
129
130static int
131checksummer(struct scatterlist *sg, void *data)
132{
133 struct ahash_request *req = data;
134
135 ahash_request_set_crypt(req, sg, NULL, sg->length);
136
137 return crypto_ahash_update(req);
138}
139
140static int
141arcfour_hmac_md5_usage_to_salt(unsigned int usage, u8 salt[4])
142{
143 unsigned int ms_usage;
144
145 switch (usage) {
146 case KG_USAGE_SIGN:
147 ms_usage = 15;
148 break;
149 case KG_USAGE_SEAL:
150 ms_usage = 13;
151 break;
152 default:
153 return -EINVAL;
154 }
155 salt[0] = (ms_usage >> 0) & 0xff;
156 salt[1] = (ms_usage >> 8) & 0xff;
157 salt[2] = (ms_usage >> 16) & 0xff;
158 salt[3] = (ms_usage >> 24) & 0xff;
159
160 return 0;
161}
162
163static u32
164make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen,
165 struct xdr_buf *body, int body_offset, u8 *cksumkey,
166 unsigned int usage, struct xdr_netobj *cksumout)
167{
168 struct scatterlist sg[1];
169 int err;
170 u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
171 u8 rc4salt[4];
172 struct crypto_ahash *md5;
173 struct crypto_ahash *hmac_md5;
174 struct ahash_request *req;
175
176 if (cksumkey == NULL)
177 return GSS_S_FAILURE;
178
179 if (cksumout->len < kctx->gk5e->cksumlength) {
180 dprintk("%s: checksum buffer length, %u, too small for %s\n",
181 __func__, cksumout->len, kctx->gk5e->name);
182 return GSS_S_FAILURE;
183 }
184
185 if (arcfour_hmac_md5_usage_to_salt(usage, rc4salt)) {
186 dprintk("%s: invalid usage value %u\n", __func__, usage);
187 return GSS_S_FAILURE;
188 }
189
190 md5 = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
191 if (IS_ERR(md5))
192 return GSS_S_FAILURE;
193
194 hmac_md5 = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0,
195 CRYPTO_ALG_ASYNC);
196 if (IS_ERR(hmac_md5)) {
197 crypto_free_ahash(md5);
198 return GSS_S_FAILURE;
199 }
200
201 req = ahash_request_alloc(md5, GFP_KERNEL);
202 if (!req) {
203 crypto_free_ahash(hmac_md5);
204 crypto_free_ahash(md5);
205 return GSS_S_FAILURE;
206 }
207
208 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
209
210 err = crypto_ahash_init(req);
211 if (err)
212 goto out;
213 sg_init_one(sg, rc4salt, 4);
214 ahash_request_set_crypt(req, sg, NULL, 4);
215 err = crypto_ahash_update(req);
216 if (err)
217 goto out;
218
219 sg_init_one(sg, header, hdrlen);
220 ahash_request_set_crypt(req, sg, NULL, hdrlen);
221 err = crypto_ahash_update(req);
222 if (err)
223 goto out;
224 err = xdr_process_buf(body, body_offset, body->len - body_offset,
225 checksummer, req);
226 if (err)
227 goto out;
228 ahash_request_set_crypt(req, NULL, checksumdata, 0);
229 err = crypto_ahash_final(req);
230 if (err)
231 goto out;
232
233 ahash_request_free(req);
234 req = ahash_request_alloc(hmac_md5, GFP_KERNEL);
235 if (!req) {
236 crypto_free_ahash(hmac_md5);
237 crypto_free_ahash(md5);
238 return GSS_S_FAILURE;
239 }
240
241 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
242
243 err = crypto_ahash_init(req);
244 if (err)
245 goto out;
246 err = crypto_ahash_setkey(hmac_md5, cksumkey, kctx->gk5e->keylength);
247 if (err)
248 goto out;
249
250 sg_init_one(sg, checksumdata, crypto_ahash_digestsize(md5));
251 ahash_request_set_crypt(req, sg, checksumdata,
252 crypto_ahash_digestsize(md5));
253 err = crypto_ahash_digest(req);
254 if (err)
255 goto out;
256
257 memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
258 cksumout->len = kctx->gk5e->cksumlength;
259out:
260 ahash_request_free(req);
261 crypto_free_ahash(md5);
262 crypto_free_ahash(hmac_md5);
263 return err ? GSS_S_FAILURE : 0;
264}
265
266/*
267 * checksum the plaintext data and hdrlen bytes of the token header
268 * The checksum is performed over the first 8 bytes of the
269 * gss token header and then over the data body
270 */
271u32
272make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
273 struct xdr_buf *body, int body_offset, u8 *cksumkey,
274 unsigned int usage, struct xdr_netobj *cksumout)
275{
276 struct crypto_ahash *tfm;
277 struct ahash_request *req;
278 struct scatterlist sg[1];
279 int err;
280 u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
281 unsigned int checksumlen;
282
283 if (kctx->gk5e->ctype == CKSUMTYPE_HMAC_MD5_ARCFOUR)
284 return make_checksum_hmac_md5(kctx, header, hdrlen,
285 body, body_offset,
286 cksumkey, usage, cksumout);
287
288 if (cksumout->len < kctx->gk5e->cksumlength) {
289 dprintk("%s: checksum buffer length, %u, too small for %s\n",
290 __func__, cksumout->len, kctx->gk5e->name);
291 return GSS_S_FAILURE;
292 }
293
294 tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
295 if (IS_ERR(tfm))
296 return GSS_S_FAILURE;
297
298 req = ahash_request_alloc(tfm, GFP_KERNEL);
299 if (!req) {
300 crypto_free_ahash(tfm);
301 return GSS_S_FAILURE;
302 }
303
304 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
305
306 checksumlen = crypto_ahash_digestsize(tfm);
307
308 if (cksumkey != NULL) {
309 err = crypto_ahash_setkey(tfm, cksumkey,
310 kctx->gk5e->keylength);
311 if (err)
312 goto out;
313 }
314
315 err = crypto_ahash_init(req);
316 if (err)
317 goto out;
318 sg_init_one(sg, header, hdrlen);
319 ahash_request_set_crypt(req, sg, NULL, hdrlen);
320 err = crypto_ahash_update(req);
321 if (err)
322 goto out;
323 err = xdr_process_buf(body, body_offset, body->len - body_offset,
324 checksummer, req);
325 if (err)
326 goto out;
327 ahash_request_set_crypt(req, NULL, checksumdata, 0);
328 err = crypto_ahash_final(req);
329 if (err)
330 goto out;
331
332 switch (kctx->gk5e->ctype) {
333 case CKSUMTYPE_RSA_MD5:
334 err = kctx->gk5e->encrypt(kctx->seq, NULL, checksumdata,
335 checksumdata, checksumlen);
336 if (err)
337 goto out;
338 memcpy(cksumout->data,
339 checksumdata + checksumlen - kctx->gk5e->cksumlength,
340 kctx->gk5e->cksumlength);
341 break;
342 case CKSUMTYPE_HMAC_SHA1_DES3:
343 memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
344 break;
345 default:
346 BUG();
347 break;
348 }
349 cksumout->len = kctx->gk5e->cksumlength;
350out:
351 ahash_request_free(req);
352 crypto_free_ahash(tfm);
353 return err ? GSS_S_FAILURE : 0;
354}
355
356/*
357 * checksum the plaintext data and hdrlen bytes of the token header
358 * Per rfc4121, sec. 4.2.4, the checksum is performed over the data
359 * body then over the first 16 octets of the MIC token
360 * Inclusion of the header data in the calculation of the
361 * checksum is optional.
362 */
363u32
364make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen,
365 struct xdr_buf *body, int body_offset, u8 *cksumkey,
366 unsigned int usage, struct xdr_netobj *cksumout)
367{
368 struct crypto_ahash *tfm;
369 struct ahash_request *req;
370 struct scatterlist sg[1];
371 int err;
372 u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
373 unsigned int checksumlen;
374
375 if (kctx->gk5e->keyed_cksum == 0) {
376 dprintk("%s: expected keyed hash for %s\n",
377 __func__, kctx->gk5e->name);
378 return GSS_S_FAILURE;
379 }
380 if (cksumkey == NULL) {
381 dprintk("%s: no key supplied for %s\n",
382 __func__, kctx->gk5e->name);
383 return GSS_S_FAILURE;
384 }
385
386 tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
387 if (IS_ERR(tfm))
388 return GSS_S_FAILURE;
389 checksumlen = crypto_ahash_digestsize(tfm);
390
391 req = ahash_request_alloc(tfm, GFP_KERNEL);
392 if (!req) {
393 crypto_free_ahash(tfm);
394 return GSS_S_FAILURE;
395 }
396
397 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
398
399 err = crypto_ahash_setkey(tfm, cksumkey, kctx->gk5e->keylength);
400 if (err)
401 goto out;
402
403 err = crypto_ahash_init(req);
404 if (err)
405 goto out;
406 err = xdr_process_buf(body, body_offset, body->len - body_offset,
407 checksummer, req);
408 if (err)
409 goto out;
410 if (header != NULL) {
411 sg_init_one(sg, header, hdrlen);
412 ahash_request_set_crypt(req, sg, NULL, hdrlen);
413 err = crypto_ahash_update(req);
414 if (err)
415 goto out;
416 }
417 ahash_request_set_crypt(req, NULL, checksumdata, 0);
418 err = crypto_ahash_final(req);
419 if (err)
420 goto out;
421
422 cksumout->len = kctx->gk5e->cksumlength;
423
424 switch (kctx->gk5e->ctype) {
425 case CKSUMTYPE_HMAC_SHA1_96_AES128:
426 case CKSUMTYPE_HMAC_SHA1_96_AES256:
427 /* note that this truncates the hash */
428 memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
429 break;
430 default:
431 BUG();
432 break;
433 }
434out:
435 ahash_request_free(req);
436 crypto_free_ahash(tfm);
437 return err ? GSS_S_FAILURE : 0;
438}
439
440struct encryptor_desc {
441 u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
442 struct skcipher_request *req;
443 int pos;
444 struct xdr_buf *outbuf;
445 struct page **pages;
446 struct scatterlist infrags[4];
447 struct scatterlist outfrags[4];
448 int fragno;
449 int fraglen;
450};
451
452static int
453encryptor(struct scatterlist *sg, void *data)
454{
455 struct encryptor_desc *desc = data;
456 struct xdr_buf *outbuf = desc->outbuf;
457 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(desc->req);
458 struct page *in_page;
459 int thislen = desc->fraglen + sg->length;
460 int fraglen, ret;
461 int page_pos;
462
463 /* Worst case is 4 fragments: head, end of page 1, start
464 * of page 2, tail. Anything more is a bug. */
465 BUG_ON(desc->fragno > 3);
466
467 page_pos = desc->pos - outbuf->head[0].iov_len;
468 if (page_pos >= 0 && page_pos < outbuf->page_len) {
469 /* pages are not in place: */
470 int i = (page_pos + outbuf->page_base) >> PAGE_SHIFT;
471 in_page = desc->pages[i];
472 } else {
473 in_page = sg_page(sg);
474 }
475 sg_set_page(&desc->infrags[desc->fragno], in_page, sg->length,
476 sg->offset);
477 sg_set_page(&desc->outfrags[desc->fragno], sg_page(sg), sg->length,
478 sg->offset);
479 desc->fragno++;
480 desc->fraglen += sg->length;
481 desc->pos += sg->length;
482
483 fraglen = thislen & (crypto_skcipher_blocksize(tfm) - 1);
484 thislen -= fraglen;
485
486 if (thislen == 0)
487 return 0;
488
489 sg_mark_end(&desc->infrags[desc->fragno - 1]);
490 sg_mark_end(&desc->outfrags[desc->fragno - 1]);
491
492 skcipher_request_set_crypt(desc->req, desc->infrags, desc->outfrags,
493 thislen, desc->iv);
494
495 ret = crypto_skcipher_encrypt(desc->req);
496 if (ret)
497 return ret;
498
499 sg_init_table(desc->infrags, 4);
500 sg_init_table(desc->outfrags, 4);
501
502 if (fraglen) {
503 sg_set_page(&desc->outfrags[0], sg_page(sg), fraglen,
504 sg->offset + sg->length - fraglen);
505 desc->infrags[0] = desc->outfrags[0];
506 sg_assign_page(&desc->infrags[0], in_page);
507 desc->fragno = 1;
508 desc->fraglen = fraglen;
509 } else {
510 desc->fragno = 0;
511 desc->fraglen = 0;
512 }
513 return 0;
514}
515
516int
517gss_encrypt_xdr_buf(struct crypto_skcipher *tfm, struct xdr_buf *buf,
518 int offset, struct page **pages)
519{
520 int ret;
521 struct encryptor_desc desc;
522 SKCIPHER_REQUEST_ON_STACK(req, tfm);
523
524 BUG_ON((buf->len - offset) % crypto_skcipher_blocksize(tfm) != 0);
525
526 skcipher_request_set_tfm(req, tfm);
527 skcipher_request_set_callback(req, 0, NULL, NULL);
528
529 memset(desc.iv, 0, sizeof(desc.iv));
530 desc.req = req;
531 desc.pos = offset;
532 desc.outbuf = buf;
533 desc.pages = pages;
534 desc.fragno = 0;
535 desc.fraglen = 0;
536
537 sg_init_table(desc.infrags, 4);
538 sg_init_table(desc.outfrags, 4);
539
540 ret = xdr_process_buf(buf, offset, buf->len - offset, encryptor, &desc);
541 skcipher_request_zero(req);
542 return ret;
543}
544
545struct decryptor_desc {
546 u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
547 struct skcipher_request *req;
548 struct scatterlist frags[4];
549 int fragno;
550 int fraglen;
551};
552
553static int
554decryptor(struct scatterlist *sg, void *data)
555{
556 struct decryptor_desc *desc = data;
557 int thislen = desc->fraglen + sg->length;
558 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(desc->req);
559 int fraglen, ret;
560
561 /* Worst case is 4 fragments: head, end of page 1, start
562 * of page 2, tail. Anything more is a bug. */
563 BUG_ON(desc->fragno > 3);
564 sg_set_page(&desc->frags[desc->fragno], sg_page(sg), sg->length,
565 sg->offset);
566 desc->fragno++;
567 desc->fraglen += sg->length;
568
569 fraglen = thislen & (crypto_skcipher_blocksize(tfm) - 1);
570 thislen -= fraglen;
571
572 if (thislen == 0)
573 return 0;
574
575 sg_mark_end(&desc->frags[desc->fragno - 1]);
576
577 skcipher_request_set_crypt(desc->req, desc->frags, desc->frags,
578 thislen, desc->iv);
579
580 ret = crypto_skcipher_decrypt(desc->req);
581 if (ret)
582 return ret;
583
584 sg_init_table(desc->frags, 4);
585
586 if (fraglen) {
587 sg_set_page(&desc->frags[0], sg_page(sg), fraglen,
588 sg->offset + sg->length - fraglen);
589 desc->fragno = 1;
590 desc->fraglen = fraglen;
591 } else {
592 desc->fragno = 0;
593 desc->fraglen = 0;
594 }
595 return 0;
596}
597
598int
599gss_decrypt_xdr_buf(struct crypto_skcipher *tfm, struct xdr_buf *buf,
600 int offset)
601{
602 int ret;
603 struct decryptor_desc desc;
604 SKCIPHER_REQUEST_ON_STACK(req, tfm);
605
606 /* XXXJBF: */
607 BUG_ON((buf->len - offset) % crypto_skcipher_blocksize(tfm) != 0);
608
609 skcipher_request_set_tfm(req, tfm);
610 skcipher_request_set_callback(req, 0, NULL, NULL);
611
612 memset(desc.iv, 0, sizeof(desc.iv));
613 desc.req = req;
614 desc.fragno = 0;
615 desc.fraglen = 0;
616
617 sg_init_table(desc.frags, 4);
618
619 ret = xdr_process_buf(buf, offset, buf->len - offset, decryptor, &desc);
620 skcipher_request_zero(req);
621 return ret;
622}
623
624/*
625 * This function makes the assumption that it was ultimately called
626 * from gss_wrap().
627 *
628 * The client auth_gss code moves any existing tail data into a
629 * separate page before calling gss_wrap.
630 * The server svcauth_gss code ensures that both the head and the
631 * tail have slack space of RPC_MAX_AUTH_SIZE before calling gss_wrap.
632 *
633 * Even with that guarantee, this function may be called more than
634 * once in the processing of gss_wrap(). The best we can do is
635 * verify at compile-time (see GSS_KRB5_SLACK_CHECK) that the
636 * largest expected shift will fit within RPC_MAX_AUTH_SIZE.
637 * At run-time we can verify that a single invocation of this
638 * function doesn't attempt to use more the RPC_MAX_AUTH_SIZE.
639 */
640
641int
642xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen)
643{
644 u8 *p;
645
646 if (shiftlen == 0)
647 return 0;
648
649 BUILD_BUG_ON(GSS_KRB5_MAX_SLACK_NEEDED > RPC_MAX_AUTH_SIZE);
650 BUG_ON(shiftlen > RPC_MAX_AUTH_SIZE);
651
652 p = buf->head[0].iov_base + base;
653
654 memmove(p + shiftlen, p, buf->head[0].iov_len - base);
655
656 buf->head[0].iov_len += shiftlen;
657 buf->len += shiftlen;
658
659 return 0;
660}
661
662static u32
663gss_krb5_cts_crypt(struct crypto_skcipher *cipher, struct xdr_buf *buf,
664 u32 offset, u8 *iv, struct page **pages, int encrypt)
665{
666 u32 ret;
667 struct scatterlist sg[1];
668 SKCIPHER_REQUEST_ON_STACK(req, cipher);
669 u8 data[GSS_KRB5_MAX_BLOCKSIZE * 2];
670 struct page **save_pages;
671 u32 len = buf->len - offset;
672
673 if (len > ARRAY_SIZE(data)) {
674 WARN_ON(0);
675 return -ENOMEM;
676 }
677
678 /*
679 * For encryption, we want to read from the cleartext
680 * page cache pages, and write the encrypted data to
681 * the supplied xdr_buf pages.
682 */
683 save_pages = buf->pages;
684 if (encrypt)
685 buf->pages = pages;
686
687 ret = read_bytes_from_xdr_buf(buf, offset, data, len);
688 buf->pages = save_pages;
689 if (ret)
690 goto out;
691
692 sg_init_one(sg, data, len);
693
694 skcipher_request_set_tfm(req, cipher);
695 skcipher_request_set_callback(req, 0, NULL, NULL);
696 skcipher_request_set_crypt(req, sg, sg, len, iv);
697
698 if (encrypt)
699 ret = crypto_skcipher_encrypt(req);
700 else
701 ret = crypto_skcipher_decrypt(req);
702
703 skcipher_request_zero(req);
704
705 if (ret)
706 goto out;
707
708 ret = write_bytes_to_xdr_buf(buf, offset, data, len);
709
710out:
711 return ret;
712}
713
714u32
715gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
716 struct xdr_buf *buf, struct page **pages)
717{
718 u32 err;
719 struct xdr_netobj hmac;
720 u8 *cksumkey;
721 u8 *ecptr;
722 struct crypto_skcipher *cipher, *aux_cipher;
723 int blocksize;
724 struct page **save_pages;
725 int nblocks, nbytes;
726 struct encryptor_desc desc;
727 u32 cbcbytes;
728 unsigned int usage;
729
730 if (kctx->initiate) {
731 cipher = kctx->initiator_enc;
732 aux_cipher = kctx->initiator_enc_aux;
733 cksumkey = kctx->initiator_integ;
734 usage = KG_USAGE_INITIATOR_SEAL;
735 } else {
736 cipher = kctx->acceptor_enc;
737 aux_cipher = kctx->acceptor_enc_aux;
738 cksumkey = kctx->acceptor_integ;
739 usage = KG_USAGE_ACCEPTOR_SEAL;
740 }
741 blocksize = crypto_skcipher_blocksize(cipher);
742
743 /* hide the gss token header and insert the confounder */
744 offset += GSS_KRB5_TOK_HDR_LEN;
745 if (xdr_extend_head(buf, offset, kctx->gk5e->conflen))
746 return GSS_S_FAILURE;
747 gss_krb5_make_confounder(buf->head[0].iov_base + offset, kctx->gk5e->conflen);
748 offset -= GSS_KRB5_TOK_HDR_LEN;
749
750 if (buf->tail[0].iov_base != NULL) {
751 ecptr = buf->tail[0].iov_base + buf->tail[0].iov_len;
752 } else {
753 buf->tail[0].iov_base = buf->head[0].iov_base
754 + buf->head[0].iov_len;
755 buf->tail[0].iov_len = 0;
756 ecptr = buf->tail[0].iov_base;
757 }
758
759 /* copy plaintext gss token header after filler (if any) */
760 memcpy(ecptr, buf->head[0].iov_base + offset, GSS_KRB5_TOK_HDR_LEN);
761 buf->tail[0].iov_len += GSS_KRB5_TOK_HDR_LEN;
762 buf->len += GSS_KRB5_TOK_HDR_LEN;
763
764 /* Do the HMAC */
765 hmac.len = GSS_KRB5_MAX_CKSUM_LEN;
766 hmac.data = buf->tail[0].iov_base + buf->tail[0].iov_len;
767
768 /*
769 * When we are called, pages points to the real page cache
770 * data -- which we can't go and encrypt! buf->pages points
771 * to scratch pages which we are going to send off to the
772 * client/server. Swap in the plaintext pages to calculate
773 * the hmac.
774 */
775 save_pages = buf->pages;
776 buf->pages = pages;
777
778 err = make_checksum_v2(kctx, NULL, 0, buf,
779 offset + GSS_KRB5_TOK_HDR_LEN,
780 cksumkey, usage, &hmac);
781 buf->pages = save_pages;
782 if (err)
783 return GSS_S_FAILURE;
784
785 nbytes = buf->len - offset - GSS_KRB5_TOK_HDR_LEN;
786 nblocks = (nbytes + blocksize - 1) / blocksize;
787 cbcbytes = 0;
788 if (nblocks > 2)
789 cbcbytes = (nblocks - 2) * blocksize;
790
791 memset(desc.iv, 0, sizeof(desc.iv));
792
793 if (cbcbytes) {
794 SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
795
796 desc.pos = offset + GSS_KRB5_TOK_HDR_LEN;
797 desc.fragno = 0;
798 desc.fraglen = 0;
799 desc.pages = pages;
800 desc.outbuf = buf;
801 desc.req = req;
802
803 skcipher_request_set_tfm(req, aux_cipher);
804 skcipher_request_set_callback(req, 0, NULL, NULL);
805
806 sg_init_table(desc.infrags, 4);
807 sg_init_table(desc.outfrags, 4);
808
809 err = xdr_process_buf(buf, offset + GSS_KRB5_TOK_HDR_LEN,
810 cbcbytes, encryptor, &desc);
811 skcipher_request_zero(req);
812 if (err)
813 goto out_err;
814 }
815
816 /* Make sure IV carries forward from any CBC results. */
817 err = gss_krb5_cts_crypt(cipher, buf,
818 offset + GSS_KRB5_TOK_HDR_LEN + cbcbytes,
819 desc.iv, pages, 1);
820 if (err) {
821 err = GSS_S_FAILURE;
822 goto out_err;
823 }
824
825 /* Now update buf to account for HMAC */
826 buf->tail[0].iov_len += kctx->gk5e->cksumlength;
827 buf->len += kctx->gk5e->cksumlength;
828
829out_err:
830 if (err)
831 err = GSS_S_FAILURE;
832 return err;
833}
834
835u32
836gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
837 u32 *headskip, u32 *tailskip)
838{
839 struct xdr_buf subbuf;
840 u32 ret = 0;
841 u8 *cksum_key;
842 struct crypto_skcipher *cipher, *aux_cipher;
843 struct xdr_netobj our_hmac_obj;
844 u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
845 u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
846 int nblocks, blocksize, cbcbytes;
847 struct decryptor_desc desc;
848 unsigned int usage;
849
850 if (kctx->initiate) {
851 cipher = kctx->acceptor_enc;
852 aux_cipher = kctx->acceptor_enc_aux;
853 cksum_key = kctx->acceptor_integ;
854 usage = KG_USAGE_ACCEPTOR_SEAL;
855 } else {
856 cipher = kctx->initiator_enc;
857 aux_cipher = kctx->initiator_enc_aux;
858 cksum_key = kctx->initiator_integ;
859 usage = KG_USAGE_INITIATOR_SEAL;
860 }
861 blocksize = crypto_skcipher_blocksize(cipher);
862
863
864 /* create a segment skipping the header and leaving out the checksum */
865 xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
866 (buf->len - offset - GSS_KRB5_TOK_HDR_LEN -
867 kctx->gk5e->cksumlength));
868
869 nblocks = (subbuf.len + blocksize - 1) / blocksize;
870
871 cbcbytes = 0;
872 if (nblocks > 2)
873 cbcbytes = (nblocks - 2) * blocksize;
874
875 memset(desc.iv, 0, sizeof(desc.iv));
876
877 if (cbcbytes) {
878 SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
879
880 desc.fragno = 0;
881 desc.fraglen = 0;
882 desc.req = req;
883
884 skcipher_request_set_tfm(req, aux_cipher);
885 skcipher_request_set_callback(req, 0, NULL, NULL);
886
887 sg_init_table(desc.frags, 4);
888
889 ret = xdr_process_buf(&subbuf, 0, cbcbytes, decryptor, &desc);
890 skcipher_request_zero(req);
891 if (ret)
892 goto out_err;
893 }
894
895 /* Make sure IV carries forward from any CBC results. */
896 ret = gss_krb5_cts_crypt(cipher, &subbuf, cbcbytes, desc.iv, NULL, 0);
897 if (ret)
898 goto out_err;
899
900
901 /* Calculate our hmac over the plaintext data */
902 our_hmac_obj.len = sizeof(our_hmac);
903 our_hmac_obj.data = our_hmac;
904
905 ret = make_checksum_v2(kctx, NULL, 0, &subbuf, 0,
906 cksum_key, usage, &our_hmac_obj);
907 if (ret)
908 goto out_err;
909
910 /* Get the packet's hmac value */
911 ret = read_bytes_from_xdr_buf(buf, buf->len - kctx->gk5e->cksumlength,
912 pkt_hmac, kctx->gk5e->cksumlength);
913 if (ret)
914 goto out_err;
915
916 if (memcmp(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
917 ret = GSS_S_BAD_SIG;
918 goto out_err;
919 }
920 *headskip = kctx->gk5e->conflen;
921 *tailskip = kctx->gk5e->cksumlength;
922out_err:
923 if (ret && ret != GSS_S_BAD_SIG)
924 ret = GSS_S_FAILURE;
925 return ret;
926}
927
928/*
929 * Compute Kseq given the initial session key and the checksum.
930 * Set the key of the given cipher.
931 */
932int
933krb5_rc4_setup_seq_key(struct krb5_ctx *kctx, struct crypto_skcipher *cipher,
934 unsigned char *cksum)
935{
936 struct crypto_shash *hmac;
937 struct shash_desc *desc;
938 u8 Kseq[GSS_KRB5_MAX_KEYLEN];
939 u32 zeroconstant = 0;
940 int err;
941
942 dprintk("%s: entered\n", __func__);
943
944 hmac = crypto_alloc_shash(kctx->gk5e->cksum_name, 0, 0);
945 if (IS_ERR(hmac)) {
946 dprintk("%s: error %ld, allocating hash '%s'\n",
947 __func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
948 return PTR_ERR(hmac);
949 }
950
951 desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac),
952 GFP_KERNEL);
953 if (!desc) {
954 dprintk("%s: failed to allocate shash descriptor for '%s'\n",
955 __func__, kctx->gk5e->cksum_name);
956 crypto_free_shash(hmac);
957 return -ENOMEM;
958 }
959
960 desc->tfm = hmac;
961 desc->flags = 0;
962
963 /* Compute intermediate Kseq from session key */
964 err = crypto_shash_setkey(hmac, kctx->Ksess, kctx->gk5e->keylength);
965 if (err)
966 goto out_err;
967
968 err = crypto_shash_digest(desc, (u8 *)&zeroconstant, 4, Kseq);
969 if (err)
970 goto out_err;
971
972 /* Compute final Kseq from the checksum and intermediate Kseq */
973 err = crypto_shash_setkey(hmac, Kseq, kctx->gk5e->keylength);
974 if (err)
975 goto out_err;
976
977 err = crypto_shash_digest(desc, cksum, 8, Kseq);
978 if (err)
979 goto out_err;
980
981 err = crypto_skcipher_setkey(cipher, Kseq, kctx->gk5e->keylength);
982 if (err)
983 goto out_err;
984
985 err = 0;
986
987out_err:
988 kzfree(desc);
989 crypto_free_shash(hmac);
990 dprintk("%s: returning %d\n", __func__, err);
991 return err;
992}
993
994/*
995 * Compute Kcrypt given the initial session key and the plaintext seqnum.
996 * Set the key of cipher kctx->enc.
997 */
998int
999krb5_rc4_setup_enc_key(struct krb5_ctx *kctx, struct crypto_skcipher *cipher,
1000 s32 seqnum)
1001{
1002 struct crypto_shash *hmac;
1003 struct shash_desc *desc;
1004 u8 Kcrypt[GSS_KRB5_MAX_KEYLEN];
1005 u8 zeroconstant[4] = {0};
1006 u8 seqnumarray[4];
1007 int err, i;
1008
1009 dprintk("%s: entered, seqnum %u\n", __func__, seqnum);
1010
1011 hmac = crypto_alloc_shash(kctx->gk5e->cksum_name, 0, 0);
1012 if (IS_ERR(hmac)) {
1013 dprintk("%s: error %ld, allocating hash '%s'\n",
1014 __func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
1015 return PTR_ERR(hmac);
1016 }
1017
1018 desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac),
1019 GFP_KERNEL);
1020 if (!desc) {
1021 dprintk("%s: failed to allocate shash descriptor for '%s'\n",
1022 __func__, kctx->gk5e->cksum_name);
1023 crypto_free_shash(hmac);
1024 return -ENOMEM;
1025 }
1026
1027 desc->tfm = hmac;
1028 desc->flags = 0;
1029
1030 /* Compute intermediate Kcrypt from session key */
1031 for (i = 0; i < kctx->gk5e->keylength; i++)
1032 Kcrypt[i] = kctx->Ksess[i] ^ 0xf0;
1033
1034 err = crypto_shash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
1035 if (err)
1036 goto out_err;
1037
1038 err = crypto_shash_digest(desc, zeroconstant, 4, Kcrypt);
1039 if (err)
1040 goto out_err;
1041
1042 /* Compute final Kcrypt from the seqnum and intermediate Kcrypt */
1043 err = crypto_shash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
1044 if (err)
1045 goto out_err;
1046
1047 seqnumarray[0] = (unsigned char) ((seqnum >> 24) & 0xff);
1048 seqnumarray[1] = (unsigned char) ((seqnum >> 16) & 0xff);
1049 seqnumarray[2] = (unsigned char) ((seqnum >> 8) & 0xff);
1050 seqnumarray[3] = (unsigned char) ((seqnum >> 0) & 0xff);
1051
1052 err = crypto_shash_digest(desc, seqnumarray, 4, Kcrypt);
1053 if (err)
1054 goto out_err;
1055
1056 err = crypto_skcipher_setkey(cipher, Kcrypt, kctx->gk5e->keylength);
1057 if (err)
1058 goto out_err;
1059
1060 err = 0;
1061
1062out_err:
1063 kzfree(desc);
1064 crypto_free_shash(hmac);
1065 dprintk("%s: returning %d\n", __func__, err);
1066 return err;
1067}
1068
1/*
2 * linux/net/sunrpc/gss_krb5_crypto.c
3 *
4 * Copyright (c) 2000-2008 The Regents of the University of Michigan.
5 * All rights reserved.
6 *
7 * Andy Adamson <andros@umich.edu>
8 * Bruce Fields <bfields@umich.edu>
9 */
10
11/*
12 * Copyright (C) 1998 by the FundsXpress, INC.
13 *
14 * All rights reserved.
15 *
16 * Export of this software from the United States of America may require
17 * a specific license from the United States Government. It is the
18 * responsibility of any person or organization contemplating export to
19 * obtain such a license before exporting.
20 *
21 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
22 * distribute this software and its documentation for any purpose and
23 * without fee is hereby granted, provided that the above copyright
24 * notice appear in all copies and that both that copyright notice and
25 * this permission notice appear in supporting documentation, and that
26 * the name of FundsXpress. not be used in advertising or publicity pertaining
27 * to distribution of the software without specific, written prior
28 * permission. FundsXpress makes no representations about the suitability of
29 * this software for any purpose. It is provided "as is" without express
30 * or implied warranty.
31 *
32 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
33 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
34 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
35 */
36
37#include <crypto/algapi.h>
38#include <crypto/hash.h>
39#include <crypto/skcipher.h>
40#include <linux/err.h>
41#include <linux/types.h>
42#include <linux/mm.h>
43#include <linux/scatterlist.h>
44#include <linux/highmem.h>
45#include <linux/pagemap.h>
46#include <linux/random.h>
47#include <linux/sunrpc/gss_krb5.h>
48#include <linux/sunrpc/xdr.h>
49
50#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
51# define RPCDBG_FACILITY RPCDBG_AUTH
52#endif
53
54u32
55krb5_encrypt(
56 struct crypto_sync_skcipher *tfm,
57 void * iv,
58 void * in,
59 void * out,
60 int length)
61{
62 u32 ret = -EINVAL;
63 struct scatterlist sg[1];
64 u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
65 SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
66
67 if (length % crypto_sync_skcipher_blocksize(tfm) != 0)
68 goto out;
69
70 if (crypto_sync_skcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
71 dprintk("RPC: gss_k5encrypt: tfm iv size too large %d\n",
72 crypto_sync_skcipher_ivsize(tfm));
73 goto out;
74 }
75
76 if (iv)
77 memcpy(local_iv, iv, crypto_sync_skcipher_ivsize(tfm));
78
79 memcpy(out, in, length);
80 sg_init_one(sg, out, length);
81
82 skcipher_request_set_sync_tfm(req, tfm);
83 skcipher_request_set_callback(req, 0, NULL, NULL);
84 skcipher_request_set_crypt(req, sg, sg, length, local_iv);
85
86 ret = crypto_skcipher_encrypt(req);
87 skcipher_request_zero(req);
88out:
89 dprintk("RPC: krb5_encrypt returns %d\n", ret);
90 return ret;
91}
92
93u32
94krb5_decrypt(
95 struct crypto_sync_skcipher *tfm,
96 void * iv,
97 void * in,
98 void * out,
99 int length)
100{
101 u32 ret = -EINVAL;
102 struct scatterlist sg[1];
103 u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
104 SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
105
106 if (length % crypto_sync_skcipher_blocksize(tfm) != 0)
107 goto out;
108
109 if (crypto_sync_skcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
110 dprintk("RPC: gss_k5decrypt: tfm iv size too large %d\n",
111 crypto_sync_skcipher_ivsize(tfm));
112 goto out;
113 }
114 if (iv)
115 memcpy(local_iv, iv, crypto_sync_skcipher_ivsize(tfm));
116
117 memcpy(out, in, length);
118 sg_init_one(sg, out, length);
119
120 skcipher_request_set_sync_tfm(req, tfm);
121 skcipher_request_set_callback(req, 0, NULL, NULL);
122 skcipher_request_set_crypt(req, sg, sg, length, local_iv);
123
124 ret = crypto_skcipher_decrypt(req);
125 skcipher_request_zero(req);
126out:
127 dprintk("RPC: gss_k5decrypt returns %d\n",ret);
128 return ret;
129}
130
131static int
132checksummer(struct scatterlist *sg, void *data)
133{
134 struct ahash_request *req = data;
135
136 ahash_request_set_crypt(req, sg, NULL, sg->length);
137
138 return crypto_ahash_update(req);
139}
140
141/*
142 * checksum the plaintext data and hdrlen bytes of the token header
143 * The checksum is performed over the first 8 bytes of the
144 * gss token header and then over the data body
145 */
146u32
147make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
148 struct xdr_buf *body, int body_offset, u8 *cksumkey,
149 unsigned int usage, struct xdr_netobj *cksumout)
150{
151 struct crypto_ahash *tfm;
152 struct ahash_request *req;
153 struct scatterlist sg[1];
154 int err = -1;
155 u8 *checksumdata;
156 unsigned int checksumlen;
157
158 if (cksumout->len < kctx->gk5e->cksumlength) {
159 dprintk("%s: checksum buffer length, %u, too small for %s\n",
160 __func__, cksumout->len, kctx->gk5e->name);
161 return GSS_S_FAILURE;
162 }
163
164 checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_KERNEL);
165 if (checksumdata == NULL)
166 return GSS_S_FAILURE;
167
168 tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
169 if (IS_ERR(tfm))
170 goto out_free_cksum;
171
172 req = ahash_request_alloc(tfm, GFP_KERNEL);
173 if (!req)
174 goto out_free_ahash;
175
176 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
177
178 checksumlen = crypto_ahash_digestsize(tfm);
179
180 if (cksumkey != NULL) {
181 err = crypto_ahash_setkey(tfm, cksumkey,
182 kctx->gk5e->keylength);
183 if (err)
184 goto out;
185 }
186
187 err = crypto_ahash_init(req);
188 if (err)
189 goto out;
190 sg_init_one(sg, header, hdrlen);
191 ahash_request_set_crypt(req, sg, NULL, hdrlen);
192 err = crypto_ahash_update(req);
193 if (err)
194 goto out;
195 err = xdr_process_buf(body, body_offset, body->len - body_offset,
196 checksummer, req);
197 if (err)
198 goto out;
199 ahash_request_set_crypt(req, NULL, checksumdata, 0);
200 err = crypto_ahash_final(req);
201 if (err)
202 goto out;
203
204 switch (kctx->gk5e->ctype) {
205 case CKSUMTYPE_RSA_MD5:
206 err = kctx->gk5e->encrypt(kctx->seq, NULL, checksumdata,
207 checksumdata, checksumlen);
208 if (err)
209 goto out;
210 memcpy(cksumout->data,
211 checksumdata + checksumlen - kctx->gk5e->cksumlength,
212 kctx->gk5e->cksumlength);
213 break;
214 case CKSUMTYPE_HMAC_SHA1_DES3:
215 memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
216 break;
217 default:
218 BUG();
219 break;
220 }
221 cksumout->len = kctx->gk5e->cksumlength;
222out:
223 ahash_request_free(req);
224out_free_ahash:
225 crypto_free_ahash(tfm);
226out_free_cksum:
227 kfree(checksumdata);
228 return err ? GSS_S_FAILURE : 0;
229}
230
231/*
232 * checksum the plaintext data and hdrlen bytes of the token header
233 * Per rfc4121, sec. 4.2.4, the checksum is performed over the data
234 * body then over the first 16 octets of the MIC token
235 * Inclusion of the header data in the calculation of the
236 * checksum is optional.
237 */
238u32
239make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen,
240 struct xdr_buf *body, int body_offset, u8 *cksumkey,
241 unsigned int usage, struct xdr_netobj *cksumout)
242{
243 struct crypto_ahash *tfm;
244 struct ahash_request *req;
245 struct scatterlist sg[1];
246 int err = -1;
247 u8 *checksumdata;
248
249 if (kctx->gk5e->keyed_cksum == 0) {
250 dprintk("%s: expected keyed hash for %s\n",
251 __func__, kctx->gk5e->name);
252 return GSS_S_FAILURE;
253 }
254 if (cksumkey == NULL) {
255 dprintk("%s: no key supplied for %s\n",
256 __func__, kctx->gk5e->name);
257 return GSS_S_FAILURE;
258 }
259
260 checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_KERNEL);
261 if (!checksumdata)
262 return GSS_S_FAILURE;
263
264 tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
265 if (IS_ERR(tfm))
266 goto out_free_cksum;
267
268 req = ahash_request_alloc(tfm, GFP_KERNEL);
269 if (!req)
270 goto out_free_ahash;
271
272 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
273
274 err = crypto_ahash_setkey(tfm, cksumkey, kctx->gk5e->keylength);
275 if (err)
276 goto out;
277
278 err = crypto_ahash_init(req);
279 if (err)
280 goto out;
281 err = xdr_process_buf(body, body_offset, body->len - body_offset,
282 checksummer, req);
283 if (err)
284 goto out;
285 if (header != NULL) {
286 sg_init_one(sg, header, hdrlen);
287 ahash_request_set_crypt(req, sg, NULL, hdrlen);
288 err = crypto_ahash_update(req);
289 if (err)
290 goto out;
291 }
292 ahash_request_set_crypt(req, NULL, checksumdata, 0);
293 err = crypto_ahash_final(req);
294 if (err)
295 goto out;
296
297 cksumout->len = kctx->gk5e->cksumlength;
298
299 switch (kctx->gk5e->ctype) {
300 case CKSUMTYPE_HMAC_SHA1_96_AES128:
301 case CKSUMTYPE_HMAC_SHA1_96_AES256:
302 /* note that this truncates the hash */
303 memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
304 break;
305 default:
306 BUG();
307 break;
308 }
309out:
310 ahash_request_free(req);
311out_free_ahash:
312 crypto_free_ahash(tfm);
313out_free_cksum:
314 kfree(checksumdata);
315 return err ? GSS_S_FAILURE : 0;
316}
317
318struct encryptor_desc {
319 u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
320 struct skcipher_request *req;
321 int pos;
322 struct xdr_buf *outbuf;
323 struct page **pages;
324 struct scatterlist infrags[4];
325 struct scatterlist outfrags[4];
326 int fragno;
327 int fraglen;
328};
329
330static int
331encryptor(struct scatterlist *sg, void *data)
332{
333 struct encryptor_desc *desc = data;
334 struct xdr_buf *outbuf = desc->outbuf;
335 struct crypto_sync_skcipher *tfm =
336 crypto_sync_skcipher_reqtfm(desc->req);
337 struct page *in_page;
338 int thislen = desc->fraglen + sg->length;
339 int fraglen, ret;
340 int page_pos;
341
342 /* Worst case is 4 fragments: head, end of page 1, start
343 * of page 2, tail. Anything more is a bug. */
344 BUG_ON(desc->fragno > 3);
345
346 page_pos = desc->pos - outbuf->head[0].iov_len;
347 if (page_pos >= 0 && page_pos < outbuf->page_len) {
348 /* pages are not in place: */
349 int i = (page_pos + outbuf->page_base) >> PAGE_SHIFT;
350 in_page = desc->pages[i];
351 } else {
352 in_page = sg_page(sg);
353 }
354 sg_set_page(&desc->infrags[desc->fragno], in_page, sg->length,
355 sg->offset);
356 sg_set_page(&desc->outfrags[desc->fragno], sg_page(sg), sg->length,
357 sg->offset);
358 desc->fragno++;
359 desc->fraglen += sg->length;
360 desc->pos += sg->length;
361
362 fraglen = thislen & (crypto_sync_skcipher_blocksize(tfm) - 1);
363 thislen -= fraglen;
364
365 if (thislen == 0)
366 return 0;
367
368 sg_mark_end(&desc->infrags[desc->fragno - 1]);
369 sg_mark_end(&desc->outfrags[desc->fragno - 1]);
370
371 skcipher_request_set_crypt(desc->req, desc->infrags, desc->outfrags,
372 thislen, desc->iv);
373
374 ret = crypto_skcipher_encrypt(desc->req);
375 if (ret)
376 return ret;
377
378 sg_init_table(desc->infrags, 4);
379 sg_init_table(desc->outfrags, 4);
380
381 if (fraglen) {
382 sg_set_page(&desc->outfrags[0], sg_page(sg), fraglen,
383 sg->offset + sg->length - fraglen);
384 desc->infrags[0] = desc->outfrags[0];
385 sg_assign_page(&desc->infrags[0], in_page);
386 desc->fragno = 1;
387 desc->fraglen = fraglen;
388 } else {
389 desc->fragno = 0;
390 desc->fraglen = 0;
391 }
392 return 0;
393}
394
395int
396gss_encrypt_xdr_buf(struct crypto_sync_skcipher *tfm, struct xdr_buf *buf,
397 int offset, struct page **pages)
398{
399 int ret;
400 struct encryptor_desc desc;
401 SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
402
403 BUG_ON((buf->len - offset) % crypto_sync_skcipher_blocksize(tfm) != 0);
404
405 skcipher_request_set_sync_tfm(req, tfm);
406 skcipher_request_set_callback(req, 0, NULL, NULL);
407
408 memset(desc.iv, 0, sizeof(desc.iv));
409 desc.req = req;
410 desc.pos = offset;
411 desc.outbuf = buf;
412 desc.pages = pages;
413 desc.fragno = 0;
414 desc.fraglen = 0;
415
416 sg_init_table(desc.infrags, 4);
417 sg_init_table(desc.outfrags, 4);
418
419 ret = xdr_process_buf(buf, offset, buf->len - offset, encryptor, &desc);
420 skcipher_request_zero(req);
421 return ret;
422}
423
424struct decryptor_desc {
425 u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
426 struct skcipher_request *req;
427 struct scatterlist frags[4];
428 int fragno;
429 int fraglen;
430};
431
432static int
433decryptor(struct scatterlist *sg, void *data)
434{
435 struct decryptor_desc *desc = data;
436 int thislen = desc->fraglen + sg->length;
437 struct crypto_sync_skcipher *tfm =
438 crypto_sync_skcipher_reqtfm(desc->req);
439 int fraglen, ret;
440
441 /* Worst case is 4 fragments: head, end of page 1, start
442 * of page 2, tail. Anything more is a bug. */
443 BUG_ON(desc->fragno > 3);
444 sg_set_page(&desc->frags[desc->fragno], sg_page(sg), sg->length,
445 sg->offset);
446 desc->fragno++;
447 desc->fraglen += sg->length;
448
449 fraglen = thislen & (crypto_sync_skcipher_blocksize(tfm) - 1);
450 thislen -= fraglen;
451
452 if (thislen == 0)
453 return 0;
454
455 sg_mark_end(&desc->frags[desc->fragno - 1]);
456
457 skcipher_request_set_crypt(desc->req, desc->frags, desc->frags,
458 thislen, desc->iv);
459
460 ret = crypto_skcipher_decrypt(desc->req);
461 if (ret)
462 return ret;
463
464 sg_init_table(desc->frags, 4);
465
466 if (fraglen) {
467 sg_set_page(&desc->frags[0], sg_page(sg), fraglen,
468 sg->offset + sg->length - fraglen);
469 desc->fragno = 1;
470 desc->fraglen = fraglen;
471 } else {
472 desc->fragno = 0;
473 desc->fraglen = 0;
474 }
475 return 0;
476}
477
478int
479gss_decrypt_xdr_buf(struct crypto_sync_skcipher *tfm, struct xdr_buf *buf,
480 int offset)
481{
482 int ret;
483 struct decryptor_desc desc;
484 SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
485
486 /* XXXJBF: */
487 BUG_ON((buf->len - offset) % crypto_sync_skcipher_blocksize(tfm) != 0);
488
489 skcipher_request_set_sync_tfm(req, tfm);
490 skcipher_request_set_callback(req, 0, NULL, NULL);
491
492 memset(desc.iv, 0, sizeof(desc.iv));
493 desc.req = req;
494 desc.fragno = 0;
495 desc.fraglen = 0;
496
497 sg_init_table(desc.frags, 4);
498
499 ret = xdr_process_buf(buf, offset, buf->len - offset, decryptor, &desc);
500 skcipher_request_zero(req);
501 return ret;
502}
503
504/*
505 * This function makes the assumption that it was ultimately called
506 * from gss_wrap().
507 *
508 * The client auth_gss code moves any existing tail data into a
509 * separate page before calling gss_wrap.
510 * The server svcauth_gss code ensures that both the head and the
511 * tail have slack space of RPC_MAX_AUTH_SIZE before calling gss_wrap.
512 *
513 * Even with that guarantee, this function may be called more than
514 * once in the processing of gss_wrap(). The best we can do is
515 * verify at compile-time (see GSS_KRB5_SLACK_CHECK) that the
516 * largest expected shift will fit within RPC_MAX_AUTH_SIZE.
517 * At run-time we can verify that a single invocation of this
518 * function doesn't attempt to use more the RPC_MAX_AUTH_SIZE.
519 */
520
521int
522xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen)
523{
524 u8 *p;
525
526 if (shiftlen == 0)
527 return 0;
528
529 BUILD_BUG_ON(GSS_KRB5_MAX_SLACK_NEEDED > RPC_MAX_AUTH_SIZE);
530 BUG_ON(shiftlen > RPC_MAX_AUTH_SIZE);
531
532 p = buf->head[0].iov_base + base;
533
534 memmove(p + shiftlen, p, buf->head[0].iov_len - base);
535
536 buf->head[0].iov_len += shiftlen;
537 buf->len += shiftlen;
538
539 return 0;
540}
541
542static u32
543gss_krb5_cts_crypt(struct crypto_sync_skcipher *cipher, struct xdr_buf *buf,
544 u32 offset, u8 *iv, struct page **pages, int encrypt)
545{
546 u32 ret;
547 struct scatterlist sg[1];
548 SYNC_SKCIPHER_REQUEST_ON_STACK(req, cipher);
549 u8 *data;
550 struct page **save_pages;
551 u32 len = buf->len - offset;
552
553 if (len > GSS_KRB5_MAX_BLOCKSIZE * 2) {
554 WARN_ON(0);
555 return -ENOMEM;
556 }
557 data = kmalloc(GSS_KRB5_MAX_BLOCKSIZE * 2, GFP_KERNEL);
558 if (!data)
559 return -ENOMEM;
560
561 /*
562 * For encryption, we want to read from the cleartext
563 * page cache pages, and write the encrypted data to
564 * the supplied xdr_buf pages.
565 */
566 save_pages = buf->pages;
567 if (encrypt)
568 buf->pages = pages;
569
570 ret = read_bytes_from_xdr_buf(buf, offset, data, len);
571 buf->pages = save_pages;
572 if (ret)
573 goto out;
574
575 sg_init_one(sg, data, len);
576
577 skcipher_request_set_sync_tfm(req, cipher);
578 skcipher_request_set_callback(req, 0, NULL, NULL);
579 skcipher_request_set_crypt(req, sg, sg, len, iv);
580
581 if (encrypt)
582 ret = crypto_skcipher_encrypt(req);
583 else
584 ret = crypto_skcipher_decrypt(req);
585
586 skcipher_request_zero(req);
587
588 if (ret)
589 goto out;
590
591 ret = write_bytes_to_xdr_buf(buf, offset, data, len);
592
593out:
594 kfree(data);
595 return ret;
596}
597
598u32
599gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
600 struct xdr_buf *buf, struct page **pages)
601{
602 u32 err;
603 struct xdr_netobj hmac;
604 u8 *cksumkey;
605 u8 *ecptr;
606 struct crypto_sync_skcipher *cipher, *aux_cipher;
607 int blocksize;
608 struct page **save_pages;
609 int nblocks, nbytes;
610 struct encryptor_desc desc;
611 u32 cbcbytes;
612 unsigned int usage;
613
614 if (kctx->initiate) {
615 cipher = kctx->initiator_enc;
616 aux_cipher = kctx->initiator_enc_aux;
617 cksumkey = kctx->initiator_integ;
618 usage = KG_USAGE_INITIATOR_SEAL;
619 } else {
620 cipher = kctx->acceptor_enc;
621 aux_cipher = kctx->acceptor_enc_aux;
622 cksumkey = kctx->acceptor_integ;
623 usage = KG_USAGE_ACCEPTOR_SEAL;
624 }
625 blocksize = crypto_sync_skcipher_blocksize(cipher);
626
627 /* hide the gss token header and insert the confounder */
628 offset += GSS_KRB5_TOK_HDR_LEN;
629 if (xdr_extend_head(buf, offset, kctx->gk5e->conflen))
630 return GSS_S_FAILURE;
631 gss_krb5_make_confounder(buf->head[0].iov_base + offset, kctx->gk5e->conflen);
632 offset -= GSS_KRB5_TOK_HDR_LEN;
633
634 if (buf->tail[0].iov_base != NULL) {
635 ecptr = buf->tail[0].iov_base + buf->tail[0].iov_len;
636 } else {
637 buf->tail[0].iov_base = buf->head[0].iov_base
638 + buf->head[0].iov_len;
639 buf->tail[0].iov_len = 0;
640 ecptr = buf->tail[0].iov_base;
641 }
642
643 /* copy plaintext gss token header after filler (if any) */
644 memcpy(ecptr, buf->head[0].iov_base + offset, GSS_KRB5_TOK_HDR_LEN);
645 buf->tail[0].iov_len += GSS_KRB5_TOK_HDR_LEN;
646 buf->len += GSS_KRB5_TOK_HDR_LEN;
647
648 /* Do the HMAC */
649 hmac.len = GSS_KRB5_MAX_CKSUM_LEN;
650 hmac.data = buf->tail[0].iov_base + buf->tail[0].iov_len;
651
652 /*
653 * When we are called, pages points to the real page cache
654 * data -- which we can't go and encrypt! buf->pages points
655 * to scratch pages which we are going to send off to the
656 * client/server. Swap in the plaintext pages to calculate
657 * the hmac.
658 */
659 save_pages = buf->pages;
660 buf->pages = pages;
661
662 err = make_checksum_v2(kctx, NULL, 0, buf,
663 offset + GSS_KRB5_TOK_HDR_LEN,
664 cksumkey, usage, &hmac);
665 buf->pages = save_pages;
666 if (err)
667 return GSS_S_FAILURE;
668
669 nbytes = buf->len - offset - GSS_KRB5_TOK_HDR_LEN;
670 nblocks = (nbytes + blocksize - 1) / blocksize;
671 cbcbytes = 0;
672 if (nblocks > 2)
673 cbcbytes = (nblocks - 2) * blocksize;
674
675 memset(desc.iv, 0, sizeof(desc.iv));
676
677 if (cbcbytes) {
678 SYNC_SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
679
680 desc.pos = offset + GSS_KRB5_TOK_HDR_LEN;
681 desc.fragno = 0;
682 desc.fraglen = 0;
683 desc.pages = pages;
684 desc.outbuf = buf;
685 desc.req = req;
686
687 skcipher_request_set_sync_tfm(req, aux_cipher);
688 skcipher_request_set_callback(req, 0, NULL, NULL);
689
690 sg_init_table(desc.infrags, 4);
691 sg_init_table(desc.outfrags, 4);
692
693 err = xdr_process_buf(buf, offset + GSS_KRB5_TOK_HDR_LEN,
694 cbcbytes, encryptor, &desc);
695 skcipher_request_zero(req);
696 if (err)
697 goto out_err;
698 }
699
700 /* Make sure IV carries forward from any CBC results. */
701 err = gss_krb5_cts_crypt(cipher, buf,
702 offset + GSS_KRB5_TOK_HDR_LEN + cbcbytes,
703 desc.iv, pages, 1);
704 if (err) {
705 err = GSS_S_FAILURE;
706 goto out_err;
707 }
708
709 /* Now update buf to account for HMAC */
710 buf->tail[0].iov_len += kctx->gk5e->cksumlength;
711 buf->len += kctx->gk5e->cksumlength;
712
713out_err:
714 if (err)
715 err = GSS_S_FAILURE;
716 return err;
717}
718
719u32
720gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
721 struct xdr_buf *buf, u32 *headskip, u32 *tailskip)
722{
723 struct xdr_buf subbuf;
724 u32 ret = 0;
725 u8 *cksum_key;
726 struct crypto_sync_skcipher *cipher, *aux_cipher;
727 struct xdr_netobj our_hmac_obj;
728 u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
729 u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
730 int nblocks, blocksize, cbcbytes;
731 struct decryptor_desc desc;
732 unsigned int usage;
733
734 if (kctx->initiate) {
735 cipher = kctx->acceptor_enc;
736 aux_cipher = kctx->acceptor_enc_aux;
737 cksum_key = kctx->acceptor_integ;
738 usage = KG_USAGE_ACCEPTOR_SEAL;
739 } else {
740 cipher = kctx->initiator_enc;
741 aux_cipher = kctx->initiator_enc_aux;
742 cksum_key = kctx->initiator_integ;
743 usage = KG_USAGE_INITIATOR_SEAL;
744 }
745 blocksize = crypto_sync_skcipher_blocksize(cipher);
746
747
748 /* create a segment skipping the header and leaving out the checksum */
749 xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
750 (len - offset - GSS_KRB5_TOK_HDR_LEN -
751 kctx->gk5e->cksumlength));
752
753 nblocks = (subbuf.len + blocksize - 1) / blocksize;
754
755 cbcbytes = 0;
756 if (nblocks > 2)
757 cbcbytes = (nblocks - 2) * blocksize;
758
759 memset(desc.iv, 0, sizeof(desc.iv));
760
761 if (cbcbytes) {
762 SYNC_SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
763
764 desc.fragno = 0;
765 desc.fraglen = 0;
766 desc.req = req;
767
768 skcipher_request_set_sync_tfm(req, aux_cipher);
769 skcipher_request_set_callback(req, 0, NULL, NULL);
770
771 sg_init_table(desc.frags, 4);
772
773 ret = xdr_process_buf(&subbuf, 0, cbcbytes, decryptor, &desc);
774 skcipher_request_zero(req);
775 if (ret)
776 goto out_err;
777 }
778
779 /* Make sure IV carries forward from any CBC results. */
780 ret = gss_krb5_cts_crypt(cipher, &subbuf, cbcbytes, desc.iv, NULL, 0);
781 if (ret)
782 goto out_err;
783
784
785 /* Calculate our hmac over the plaintext data */
786 our_hmac_obj.len = sizeof(our_hmac);
787 our_hmac_obj.data = our_hmac;
788
789 ret = make_checksum_v2(kctx, NULL, 0, &subbuf, 0,
790 cksum_key, usage, &our_hmac_obj);
791 if (ret)
792 goto out_err;
793
794 /* Get the packet's hmac value */
795 ret = read_bytes_from_xdr_buf(buf, len - kctx->gk5e->cksumlength,
796 pkt_hmac, kctx->gk5e->cksumlength);
797 if (ret)
798 goto out_err;
799
800 if (crypto_memneq(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
801 ret = GSS_S_BAD_SIG;
802 goto out_err;
803 }
804 *headskip = kctx->gk5e->conflen;
805 *tailskip = kctx->gk5e->cksumlength;
806out_err:
807 if (ret && ret != GSS_S_BAD_SIG)
808 ret = GSS_S_FAILURE;
809 return ret;
810}