2 * linux/net/sunrpc/gss_krb5_crypto.c
4 * Copyright (c) 2000-2008 The Regents of the University of Michigan.
7 * Andy Adamson <andros@umich.edu>
8 * Bruce Fields <bfields@umich.edu>
12 * Copyright (C) 1998 by the FundsXpress, INC.
14 * All rights reserved.
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.
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.
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.
37 #include <crypto/hash.h>
38 #include <crypto/skcipher.h>
39 #include <linux/err.h>
40 #include <linux/types.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>
49 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
50 # define RPCDBG_FACILITY RPCDBG_AUTH
55 struct crypto_skcipher *tfm,
62 struct scatterlist sg[1];
63 u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
64 SKCIPHER_REQUEST_ON_STACK(req, tfm);
66 if (length % crypto_skcipher_blocksize(tfm) != 0)
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));
76 memcpy(local_iv, iv, crypto_skcipher_ivsize(tfm));
78 memcpy(out, in, length);
79 sg_init_one(sg, out, length);
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);
85 ret = crypto_skcipher_encrypt(req);
86 skcipher_request_zero(req);
88 dprintk("RPC: krb5_encrypt returns %d\n", ret);
94 struct crypto_skcipher *tfm,
101 struct scatterlist sg[1];
102 u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
103 SKCIPHER_REQUEST_ON_STACK(req, tfm);
105 if (length % crypto_skcipher_blocksize(tfm) != 0)
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));
114 memcpy(local_iv,iv, crypto_skcipher_ivsize(tfm));
116 memcpy(out, in, length);
117 sg_init_one(sg, out, length);
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);
123 ret = crypto_skcipher_decrypt(req);
124 skcipher_request_zero(req);
126 dprintk("RPC: gss_k5decrypt returns %d\n",ret);
131 checksummer(struct scatterlist *sg, void *data)
133 struct ahash_request *req = data;
135 ahash_request_set_crypt(req, sg, NULL, sg->length);
137 return crypto_ahash_update(req);
141 arcfour_hmac_md5_usage_to_salt(unsigned int usage, u8 salt[4])
143 unsigned int ms_usage;
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;
164 make_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)
168 struct scatterlist sg[1];
172 struct crypto_ahash *md5;
173 struct crypto_ahash *hmac_md5;
174 struct ahash_request *req;
176 if (cksumkey == NULL)
177 return GSS_S_FAILURE;
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;
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;
190 checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS);
192 return GSS_S_FAILURE;
194 md5 = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
198 hmac_md5 = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0,
200 if (IS_ERR(hmac_md5))
203 req = ahash_request_alloc(md5, GFP_NOFS);
205 goto out_free_hmac_md5;
207 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
209 err = crypto_ahash_init(req);
212 sg_init_one(sg, rc4salt, 4);
213 ahash_request_set_crypt(req, sg, NULL, 4);
214 err = crypto_ahash_update(req);
218 sg_init_one(sg, header, hdrlen);
219 ahash_request_set_crypt(req, sg, NULL, hdrlen);
220 err = crypto_ahash_update(req);
223 err = xdr_process_buf(body, body_offset, body->len - body_offset,
227 ahash_request_set_crypt(req, NULL, checksumdata, 0);
228 err = crypto_ahash_final(req);
232 ahash_request_free(req);
233 req = ahash_request_alloc(hmac_md5, GFP_NOFS);
235 goto out_free_hmac_md5;
237 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
239 err = crypto_ahash_init(req);
242 err = crypto_ahash_setkey(hmac_md5, cksumkey, kctx->gk5e->keylength);
246 sg_init_one(sg, checksumdata, crypto_ahash_digestsize(md5));
247 ahash_request_set_crypt(req, sg, checksumdata,
248 crypto_ahash_digestsize(md5));
249 err = crypto_ahash_digest(req);
253 memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
254 cksumout->len = kctx->gk5e->cksumlength;
256 ahash_request_free(req);
258 crypto_free_ahash(hmac_md5);
260 crypto_free_ahash(md5);
263 return err ? GSS_S_FAILURE : 0;
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
272 make_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)
276 struct crypto_ahash *tfm;
277 struct ahash_request *req;
278 struct scatterlist sg[1];
281 unsigned int checksumlen;
283 if (kctx->gk5e->ctype == CKSUMTYPE_HMAC_MD5_ARCFOUR)
284 return make_checksum_hmac_md5(kctx, header, hdrlen,
286 cksumkey, usage, cksumout);
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;
294 checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS);
295 if (checksumdata == NULL)
296 return GSS_S_FAILURE;
298 tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
302 req = ahash_request_alloc(tfm, GFP_NOFS);
306 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
308 checksumlen = crypto_ahash_digestsize(tfm);
310 if (cksumkey != NULL) {
311 err = crypto_ahash_setkey(tfm, cksumkey,
312 kctx->gk5e->keylength);
317 err = crypto_ahash_init(req);
320 sg_init_one(sg, header, hdrlen);
321 ahash_request_set_crypt(req, sg, NULL, hdrlen);
322 err = crypto_ahash_update(req);
325 err = xdr_process_buf(body, body_offset, body->len - body_offset,
329 ahash_request_set_crypt(req, NULL, checksumdata, 0);
330 err = crypto_ahash_final(req);
334 switch (kctx->gk5e->ctype) {
335 case CKSUMTYPE_RSA_MD5:
336 err = kctx->gk5e->encrypt(kctx->seq, NULL, checksumdata,
337 checksumdata, checksumlen);
340 memcpy(cksumout->data,
341 checksumdata + checksumlen - kctx->gk5e->cksumlength,
342 kctx->gk5e->cksumlength);
344 case CKSUMTYPE_HMAC_SHA1_DES3:
345 memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
351 cksumout->len = kctx->gk5e->cksumlength;
353 ahash_request_free(req);
355 crypto_free_ahash(tfm);
358 return err ? GSS_S_FAILURE : 0;
362 * checksum the plaintext data and hdrlen bytes of the token header
363 * Per rfc4121, sec. 4.2.4, the checksum is performed over the data
364 * body then over the first 16 octets of the MIC token
365 * Inclusion of the header data in the calculation of the
366 * checksum is optional.
369 make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen,
370 struct xdr_buf *body, int body_offset, u8 *cksumkey,
371 unsigned int usage, struct xdr_netobj *cksumout)
373 struct crypto_ahash *tfm;
374 struct ahash_request *req;
375 struct scatterlist sg[1];
378 unsigned int checksumlen;
380 if (kctx->gk5e->keyed_cksum == 0) {
381 dprintk("%s: expected keyed hash for %s\n",
382 __func__, kctx->gk5e->name);
383 return GSS_S_FAILURE;
385 if (cksumkey == NULL) {
386 dprintk("%s: no key supplied for %s\n",
387 __func__, kctx->gk5e->name);
388 return GSS_S_FAILURE;
391 checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS);
393 return GSS_S_FAILURE;
395 tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
398 checksumlen = crypto_ahash_digestsize(tfm);
400 req = ahash_request_alloc(tfm, GFP_NOFS);
404 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
406 err = crypto_ahash_setkey(tfm, cksumkey, kctx->gk5e->keylength);
410 err = crypto_ahash_init(req);
413 err = xdr_process_buf(body, body_offset, body->len - body_offset,
417 if (header != NULL) {
418 sg_init_one(sg, header, hdrlen);
419 ahash_request_set_crypt(req, sg, NULL, hdrlen);
420 err = crypto_ahash_update(req);
424 ahash_request_set_crypt(req, NULL, checksumdata, 0);
425 err = crypto_ahash_final(req);
429 cksumout->len = kctx->gk5e->cksumlength;
431 switch (kctx->gk5e->ctype) {
432 case CKSUMTYPE_HMAC_SHA1_96_AES128:
433 case CKSUMTYPE_HMAC_SHA1_96_AES256:
434 /* note that this truncates the hash */
435 memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
442 ahash_request_free(req);
444 crypto_free_ahash(tfm);
447 return err ? GSS_S_FAILURE : 0;
450 struct encryptor_desc {
451 u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
452 struct skcipher_request *req;
454 struct xdr_buf *outbuf;
456 struct scatterlist infrags[4];
457 struct scatterlist outfrags[4];
463 encryptor(struct scatterlist *sg, void *data)
465 struct encryptor_desc *desc = data;
466 struct xdr_buf *outbuf = desc->outbuf;
467 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(desc->req);
468 struct page *in_page;
469 int thislen = desc->fraglen + sg->length;
473 /* Worst case is 4 fragments: head, end of page 1, start
474 * of page 2, tail. Anything more is a bug. */
475 BUG_ON(desc->fragno > 3);
477 page_pos = desc->pos - outbuf->head[0].iov_len;
478 if (page_pos >= 0 && page_pos < outbuf->page_len) {
479 /* pages are not in place: */
480 int i = (page_pos + outbuf->page_base) >> PAGE_SHIFT;
481 in_page = desc->pages[i];
483 in_page = sg_page(sg);
485 sg_set_page(&desc->infrags[desc->fragno], in_page, sg->length,
487 sg_set_page(&desc->outfrags[desc->fragno], sg_page(sg), sg->length,
490 desc->fraglen += sg->length;
491 desc->pos += sg->length;
493 fraglen = thislen & (crypto_skcipher_blocksize(tfm) - 1);
499 sg_mark_end(&desc->infrags[desc->fragno - 1]);
500 sg_mark_end(&desc->outfrags[desc->fragno - 1]);
502 skcipher_request_set_crypt(desc->req, desc->infrags, desc->outfrags,
505 ret = crypto_skcipher_encrypt(desc->req);
509 sg_init_table(desc->infrags, 4);
510 sg_init_table(desc->outfrags, 4);
513 sg_set_page(&desc->outfrags[0], sg_page(sg), fraglen,
514 sg->offset + sg->length - fraglen);
515 desc->infrags[0] = desc->outfrags[0];
516 sg_assign_page(&desc->infrags[0], in_page);
518 desc->fraglen = fraglen;
527 gss_encrypt_xdr_buf(struct crypto_skcipher *tfm, struct xdr_buf *buf,
528 int offset, struct page **pages)
531 struct encryptor_desc desc;
532 SKCIPHER_REQUEST_ON_STACK(req, tfm);
534 BUG_ON((buf->len - offset) % crypto_skcipher_blocksize(tfm) != 0);
536 skcipher_request_set_tfm(req, tfm);
537 skcipher_request_set_callback(req, 0, NULL, NULL);
539 memset(desc.iv, 0, sizeof(desc.iv));
547 sg_init_table(desc.infrags, 4);
548 sg_init_table(desc.outfrags, 4);
550 ret = xdr_process_buf(buf, offset, buf->len - offset, encryptor, &desc);
551 skcipher_request_zero(req);
555 struct decryptor_desc {
556 u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
557 struct skcipher_request *req;
558 struct scatterlist frags[4];
564 decryptor(struct scatterlist *sg, void *data)
566 struct decryptor_desc *desc = data;
567 int thislen = desc->fraglen + sg->length;
568 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(desc->req);
571 /* Worst case is 4 fragments: head, end of page 1, start
572 * of page 2, tail. Anything more is a bug. */
573 BUG_ON(desc->fragno > 3);
574 sg_set_page(&desc->frags[desc->fragno], sg_page(sg), sg->length,
577 desc->fraglen += sg->length;
579 fraglen = thislen & (crypto_skcipher_blocksize(tfm) - 1);
585 sg_mark_end(&desc->frags[desc->fragno - 1]);
587 skcipher_request_set_crypt(desc->req, desc->frags, desc->frags,
590 ret = crypto_skcipher_decrypt(desc->req);
594 sg_init_table(desc->frags, 4);
597 sg_set_page(&desc->frags[0], sg_page(sg), fraglen,
598 sg->offset + sg->length - fraglen);
600 desc->fraglen = fraglen;
609 gss_decrypt_xdr_buf(struct crypto_skcipher *tfm, struct xdr_buf *buf,
613 struct decryptor_desc desc;
614 SKCIPHER_REQUEST_ON_STACK(req, tfm);
617 BUG_ON((buf->len - offset) % crypto_skcipher_blocksize(tfm) != 0);
619 skcipher_request_set_tfm(req, tfm);
620 skcipher_request_set_callback(req, 0, NULL, NULL);
622 memset(desc.iv, 0, sizeof(desc.iv));
627 sg_init_table(desc.frags, 4);
629 ret = xdr_process_buf(buf, offset, buf->len - offset, decryptor, &desc);
630 skcipher_request_zero(req);
635 * This function makes the assumption that it was ultimately called
638 * The client auth_gss code moves any existing tail data into a
639 * separate page before calling gss_wrap.
640 * The server svcauth_gss code ensures that both the head and the
641 * tail have slack space of RPC_MAX_AUTH_SIZE before calling gss_wrap.
643 * Even with that guarantee, this function may be called more than
644 * once in the processing of gss_wrap(). The best we can do is
645 * verify at compile-time (see GSS_KRB5_SLACK_CHECK) that the
646 * largest expected shift will fit within RPC_MAX_AUTH_SIZE.
647 * At run-time we can verify that a single invocation of this
648 * function doesn't attempt to use more the RPC_MAX_AUTH_SIZE.
652 xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen)
659 BUILD_BUG_ON(GSS_KRB5_MAX_SLACK_NEEDED > RPC_MAX_AUTH_SIZE);
660 BUG_ON(shiftlen > RPC_MAX_AUTH_SIZE);
662 p = buf->head[0].iov_base + base;
664 memmove(p + shiftlen, p, buf->head[0].iov_len - base);
666 buf->head[0].iov_len += shiftlen;
667 buf->len += shiftlen;
673 gss_krb5_cts_crypt(struct crypto_skcipher *cipher, struct xdr_buf *buf,
674 u32 offset, u8 *iv, struct page **pages, int encrypt)
677 struct scatterlist sg[1];
678 SKCIPHER_REQUEST_ON_STACK(req, cipher);
680 struct page **save_pages;
681 u32 len = buf->len - offset;
683 if (len > GSS_KRB5_MAX_BLOCKSIZE * 2) {
687 data = kmalloc(GSS_KRB5_MAX_BLOCKSIZE * 2, GFP_NOFS);
692 * For encryption, we want to read from the cleartext
693 * page cache pages, and write the encrypted data to
694 * the supplied xdr_buf pages.
696 save_pages = buf->pages;
700 ret = read_bytes_from_xdr_buf(buf, offset, data, len);
701 buf->pages = save_pages;
705 sg_init_one(sg, data, len);
707 skcipher_request_set_tfm(req, cipher);
708 skcipher_request_set_callback(req, 0, NULL, NULL);
709 skcipher_request_set_crypt(req, sg, sg, len, iv);
712 ret = crypto_skcipher_encrypt(req);
714 ret = crypto_skcipher_decrypt(req);
716 skcipher_request_zero(req);
721 ret = write_bytes_to_xdr_buf(buf, offset, data, len);
729 gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
730 struct xdr_buf *buf, struct page **pages)
733 struct xdr_netobj hmac;
736 struct crypto_skcipher *cipher, *aux_cipher;
738 struct page **save_pages;
740 struct encryptor_desc desc;
744 if (kctx->initiate) {
745 cipher = kctx->initiator_enc;
746 aux_cipher = kctx->initiator_enc_aux;
747 cksumkey = kctx->initiator_integ;
748 usage = KG_USAGE_INITIATOR_SEAL;
750 cipher = kctx->acceptor_enc;
751 aux_cipher = kctx->acceptor_enc_aux;
752 cksumkey = kctx->acceptor_integ;
753 usage = KG_USAGE_ACCEPTOR_SEAL;
755 blocksize = crypto_skcipher_blocksize(cipher);
757 /* hide the gss token header and insert the confounder */
758 offset += GSS_KRB5_TOK_HDR_LEN;
759 if (xdr_extend_head(buf, offset, kctx->gk5e->conflen))
760 return GSS_S_FAILURE;
761 gss_krb5_make_confounder(buf->head[0].iov_base + offset, kctx->gk5e->conflen);
762 offset -= GSS_KRB5_TOK_HDR_LEN;
764 if (buf->tail[0].iov_base != NULL) {
765 ecptr = buf->tail[0].iov_base + buf->tail[0].iov_len;
767 buf->tail[0].iov_base = buf->head[0].iov_base
768 + buf->head[0].iov_len;
769 buf->tail[0].iov_len = 0;
770 ecptr = buf->tail[0].iov_base;
773 /* copy plaintext gss token header after filler (if any) */
774 memcpy(ecptr, buf->head[0].iov_base + offset, GSS_KRB5_TOK_HDR_LEN);
775 buf->tail[0].iov_len += GSS_KRB5_TOK_HDR_LEN;
776 buf->len += GSS_KRB5_TOK_HDR_LEN;
779 hmac.len = GSS_KRB5_MAX_CKSUM_LEN;
780 hmac.data = buf->tail[0].iov_base + buf->tail[0].iov_len;
783 * When we are called, pages points to the real page cache
784 * data -- which we can't go and encrypt! buf->pages points
785 * to scratch pages which we are going to send off to the
786 * client/server. Swap in the plaintext pages to calculate
789 save_pages = buf->pages;
792 err = make_checksum_v2(kctx, NULL, 0, buf,
793 offset + GSS_KRB5_TOK_HDR_LEN,
794 cksumkey, usage, &hmac);
795 buf->pages = save_pages;
797 return GSS_S_FAILURE;
799 nbytes = buf->len - offset - GSS_KRB5_TOK_HDR_LEN;
800 nblocks = (nbytes + blocksize - 1) / blocksize;
803 cbcbytes = (nblocks - 2) * blocksize;
805 memset(desc.iv, 0, sizeof(desc.iv));
808 SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
810 desc.pos = offset + GSS_KRB5_TOK_HDR_LEN;
817 skcipher_request_set_tfm(req, aux_cipher);
818 skcipher_request_set_callback(req, 0, NULL, NULL);
820 sg_init_table(desc.infrags, 4);
821 sg_init_table(desc.outfrags, 4);
823 err = xdr_process_buf(buf, offset + GSS_KRB5_TOK_HDR_LEN,
824 cbcbytes, encryptor, &desc);
825 skcipher_request_zero(req);
830 /* Make sure IV carries forward from any CBC results. */
831 err = gss_krb5_cts_crypt(cipher, buf,
832 offset + GSS_KRB5_TOK_HDR_LEN + cbcbytes,
839 /* Now update buf to account for HMAC */
840 buf->tail[0].iov_len += kctx->gk5e->cksumlength;
841 buf->len += kctx->gk5e->cksumlength;
850 gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
851 u32 *headskip, u32 *tailskip)
853 struct xdr_buf subbuf;
856 struct crypto_skcipher *cipher, *aux_cipher;
857 struct xdr_netobj our_hmac_obj;
858 u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
859 u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
860 int nblocks, blocksize, cbcbytes;
861 struct decryptor_desc desc;
864 if (kctx->initiate) {
865 cipher = kctx->acceptor_enc;
866 aux_cipher = kctx->acceptor_enc_aux;
867 cksum_key = kctx->acceptor_integ;
868 usage = KG_USAGE_ACCEPTOR_SEAL;
870 cipher = kctx->initiator_enc;
871 aux_cipher = kctx->initiator_enc_aux;
872 cksum_key = kctx->initiator_integ;
873 usage = KG_USAGE_INITIATOR_SEAL;
875 blocksize = crypto_skcipher_blocksize(cipher);
878 /* create a segment skipping the header and leaving out the checksum */
879 xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
880 (buf->len - offset - GSS_KRB5_TOK_HDR_LEN -
881 kctx->gk5e->cksumlength));
883 nblocks = (subbuf.len + blocksize - 1) / blocksize;
887 cbcbytes = (nblocks - 2) * blocksize;
889 memset(desc.iv, 0, sizeof(desc.iv));
892 SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
898 skcipher_request_set_tfm(req, aux_cipher);
899 skcipher_request_set_callback(req, 0, NULL, NULL);
901 sg_init_table(desc.frags, 4);
903 ret = xdr_process_buf(&subbuf, 0, cbcbytes, decryptor, &desc);
904 skcipher_request_zero(req);
909 /* Make sure IV carries forward from any CBC results. */
910 ret = gss_krb5_cts_crypt(cipher, &subbuf, cbcbytes, desc.iv, NULL, 0);
915 /* Calculate our hmac over the plaintext data */
916 our_hmac_obj.len = sizeof(our_hmac);
917 our_hmac_obj.data = our_hmac;
919 ret = make_checksum_v2(kctx, NULL, 0, &subbuf, 0,
920 cksum_key, usage, &our_hmac_obj);
924 /* Get the packet's hmac value */
925 ret = read_bytes_from_xdr_buf(buf, buf->len - kctx->gk5e->cksumlength,
926 pkt_hmac, kctx->gk5e->cksumlength);
930 if (memcmp(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
934 *headskip = kctx->gk5e->conflen;
935 *tailskip = kctx->gk5e->cksumlength;
937 if (ret && ret != GSS_S_BAD_SIG)
943 * Compute Kseq given the initial session key and the checksum.
944 * Set the key of the given cipher.
947 krb5_rc4_setup_seq_key(struct krb5_ctx *kctx, struct crypto_skcipher *cipher,
948 unsigned char *cksum)
950 struct crypto_shash *hmac;
951 struct shash_desc *desc;
952 u8 Kseq[GSS_KRB5_MAX_KEYLEN];
953 u32 zeroconstant = 0;
956 dprintk("%s: entered\n", __func__);
958 hmac = crypto_alloc_shash(kctx->gk5e->cksum_name, 0, 0);
960 dprintk("%s: error %ld, allocating hash '%s'\n",
961 __func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
962 return PTR_ERR(hmac);
965 desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac),
968 dprintk("%s: failed to allocate shash descriptor for '%s'\n",
969 __func__, kctx->gk5e->cksum_name);
970 crypto_free_shash(hmac);
977 /* Compute intermediate Kseq from session key */
978 err = crypto_shash_setkey(hmac, kctx->Ksess, kctx->gk5e->keylength);
982 err = crypto_shash_digest(desc, (u8 *)&zeroconstant, 4, Kseq);
986 /* Compute final Kseq from the checksum and intermediate Kseq */
987 err = crypto_shash_setkey(hmac, Kseq, kctx->gk5e->keylength);
991 err = crypto_shash_digest(desc, cksum, 8, Kseq);
995 err = crypto_skcipher_setkey(cipher, Kseq, kctx->gk5e->keylength);
1003 crypto_free_shash(hmac);
1004 dprintk("%s: returning %d\n", __func__, err);
1009 * Compute Kcrypt given the initial session key and the plaintext seqnum.
1010 * Set the key of cipher kctx->enc.
1013 krb5_rc4_setup_enc_key(struct krb5_ctx *kctx, struct crypto_skcipher *cipher,
1016 struct crypto_shash *hmac;
1017 struct shash_desc *desc;
1018 u8 Kcrypt[GSS_KRB5_MAX_KEYLEN];
1019 u8 zeroconstant[4] = {0};
1023 dprintk("%s: entered, seqnum %u\n", __func__, seqnum);
1025 hmac = crypto_alloc_shash(kctx->gk5e->cksum_name, 0, 0);
1027 dprintk("%s: error %ld, allocating hash '%s'\n",
1028 __func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
1029 return PTR_ERR(hmac);
1032 desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac),
1035 dprintk("%s: failed to allocate shash descriptor for '%s'\n",
1036 __func__, kctx->gk5e->cksum_name);
1037 crypto_free_shash(hmac);
1044 /* Compute intermediate Kcrypt from session key */
1045 for (i = 0; i < kctx->gk5e->keylength; i++)
1046 Kcrypt[i] = kctx->Ksess[i] ^ 0xf0;
1048 err = crypto_shash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
1052 err = crypto_shash_digest(desc, zeroconstant, 4, Kcrypt);
1056 /* Compute final Kcrypt from the seqnum and intermediate Kcrypt */
1057 err = crypto_shash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
1061 seqnumarray[0] = (unsigned char) ((seqnum >> 24) & 0xff);
1062 seqnumarray[1] = (unsigned char) ((seqnum >> 16) & 0xff);
1063 seqnumarray[2] = (unsigned char) ((seqnum >> 8) & 0xff);
1064 seqnumarray[3] = (unsigned char) ((seqnum >> 0) & 0xff);
1066 err = crypto_shash_digest(desc, seqnumarray, 4, Kcrypt);
1070 err = crypto_skcipher_setkey(cipher, Kcrypt, kctx->gk5e->keylength);
1078 crypto_free_shash(hmac);
1079 dprintk("%s: returning %d\n", __func__, err);