1/*
2 *  linux/net/sunrpc/gss_krb5_mech.c
3 *
4 *  Copyright (c) 2001-2008 The Regents of the University of Michigan.
5 *  All rights reserved.
6 *
7 *  Andy Adamson <andros@umich.edu>
8 *  J. Bruce Fields <bfields@umich.edu>
9 *
10 *  Redistribution and use in source and binary forms, with or without
11 *  modification, are permitted provided that the following conditions
12 *  are met:
13 *
14 *  1. Redistributions of source code must retain the above copyright
15 *     notice, this list of conditions and the following disclaimer.
16 *  2. Redistributions in binary form must reproduce the above copyright
17 *     notice, this list of conditions and the following disclaimer in the
18 *     documentation and/or other materials provided with the distribution.
19 *  3. Neither the name of the University nor the names of its
20 *     contributors may be used to endorse or promote products derived
21 *     from this software without specific prior written permission.
22 *
23 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
24 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 *
35 */
36
37#include <linux/err.h>
38#include <linux/module.h>
39#include <linux/init.h>
40#include <linux/types.h>
41#include <linux/slab.h>
42#include <linux/sunrpc/auth.h>
43#include <linux/sunrpc/gss_krb5.h>
44#include <linux/sunrpc/xdr.h>
45#include <linux/crypto.h>
46#include <linux/sunrpc/gss_krb5_enctypes.h>
47
48#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
49# define RPCDBG_FACILITY	RPCDBG_AUTH
50#endif
51
52static struct gss_api_mech gss_kerberos_mech;	/* forward declaration */
53
54static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
55	/*
56	 * DES (All DES enctypes are mapped to the same gss functionality)
57	 */
58	{
59	  .etype = ENCTYPE_DES_CBC_RAW,
60	  .ctype = CKSUMTYPE_RSA_MD5,
61	  .name = "des-cbc-crc",
62	  .encrypt_name = "cbc(des)",
63	  .cksum_name = "md5",
64	  .encrypt = krb5_encrypt,
65	  .decrypt = krb5_decrypt,
66	  .mk_key = NULL,
67	  .signalg = SGN_ALG_DES_MAC_MD5,
68	  .sealalg = SEAL_ALG_DES,
69	  .keybytes = 7,
70	  .keylength = 8,
71	  .blocksize = 8,
72	  .conflen = 8,
73	  .cksumlength = 8,
74	  .keyed_cksum = 0,
75	},
76	/*
77	 * RC4-HMAC
78	 */
79	{
80	  .etype = ENCTYPE_ARCFOUR_HMAC,
81	  .ctype = CKSUMTYPE_HMAC_MD5_ARCFOUR,
82	  .name = "rc4-hmac",
83	  .encrypt_name = "ecb(arc4)",
84	  .cksum_name = "hmac(md5)",
85	  .encrypt = krb5_encrypt,
86	  .decrypt = krb5_decrypt,
87	  .mk_key = NULL,
88	  .signalg = SGN_ALG_HMAC_MD5,
89	  .sealalg = SEAL_ALG_MICROSOFT_RC4,
90	  .keybytes = 16,
91	  .keylength = 16,
92	  .blocksize = 1,
93	  .conflen = 8,
94	  .cksumlength = 8,
95	  .keyed_cksum = 1,
96	},
97	/*
98	 * 3DES
99	 */
100	{
101	  .etype = ENCTYPE_DES3_CBC_RAW,
102	  .ctype = CKSUMTYPE_HMAC_SHA1_DES3,
103	  .name = "des3-hmac-sha1",
104	  .encrypt_name = "cbc(des3_ede)",
105	  .cksum_name = "hmac(sha1)",
106	  .encrypt = krb5_encrypt,
107	  .decrypt = krb5_decrypt,
108	  .mk_key = gss_krb5_des3_make_key,
109	  .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
110	  .sealalg = SEAL_ALG_DES3KD,
111	  .keybytes = 21,
112	  .keylength = 24,
113	  .blocksize = 8,
114	  .conflen = 8,
115	  .cksumlength = 20,
116	  .keyed_cksum = 1,
117	},
118	/*
119	 * AES128
120	 */
121	{
122	  .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
123	  .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
124	  .name = "aes128-cts",
125	  .encrypt_name = "cts(cbc(aes))",
126	  .cksum_name = "hmac(sha1)",
127	  .encrypt = krb5_encrypt,
128	  .decrypt = krb5_decrypt,
129	  .mk_key = gss_krb5_aes_make_key,
130	  .encrypt_v2 = gss_krb5_aes_encrypt,
131	  .decrypt_v2 = gss_krb5_aes_decrypt,
132	  .signalg = -1,
133	  .sealalg = -1,
134	  .keybytes = 16,
135	  .keylength = 16,
136	  .blocksize = 16,
137	  .conflen = 16,
138	  .cksumlength = 12,
139	  .keyed_cksum = 1,
140	},
141	/*
142	 * AES256
143	 */
144	{
145	  .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
146	  .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
147	  .name = "aes256-cts",
148	  .encrypt_name = "cts(cbc(aes))",
149	  .cksum_name = "hmac(sha1)",
150	  .encrypt = krb5_encrypt,
151	  .decrypt = krb5_decrypt,
152	  .mk_key = gss_krb5_aes_make_key,
153	  .encrypt_v2 = gss_krb5_aes_encrypt,
154	  .decrypt_v2 = gss_krb5_aes_decrypt,
155	  .signalg = -1,
156	  .sealalg = -1,
157	  .keybytes = 32,
158	  .keylength = 32,
159	  .blocksize = 16,
160	  .conflen = 16,
161	  .cksumlength = 12,
162	  .keyed_cksum = 1,
163	},
164};
165
166static const int num_supported_enctypes =
167	ARRAY_SIZE(supported_gss_krb5_enctypes);
168
169static int
170supported_gss_krb5_enctype(int etype)
171{
172	int i;
173	for (i = 0; i < num_supported_enctypes; i++)
174		if (supported_gss_krb5_enctypes[i].etype == etype)
175			return 1;
176	return 0;
177}
178
179static const struct gss_krb5_enctype *
180get_gss_krb5_enctype(int etype)
181{
182	int i;
183	for (i = 0; i < num_supported_enctypes; i++)
184		if (supported_gss_krb5_enctypes[i].etype == etype)
185			return &supported_gss_krb5_enctypes[i];
186	return NULL;
187}
188
189static const void *
190simple_get_bytes(const void *p, const void *end, void *res, int len)
191{
192	const void *q = (const void *)((const char *)p + len);
193	if (unlikely(q > end || q < p))
194		return ERR_PTR(-EFAULT);
195	memcpy(res, p, len);
196	return q;
197}
198
199static const void *
200simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
201{
202	const void *q;
203	unsigned int len;
204
205	p = simple_get_bytes(p, end, &len, sizeof(len));
206	if (IS_ERR(p))
207		return p;
208	q = (const void *)((const char *)p + len);
209	if (unlikely(q > end || q < p))
210		return ERR_PTR(-EFAULT);
211	res->data = kmemdup(p, len, GFP_NOFS);
212	if (unlikely(res->data == NULL))
213		return ERR_PTR(-ENOMEM);
214	res->len = len;
215	return q;
216}
217
218static inline const void *
219get_key(const void *p, const void *end,
220	struct krb5_ctx *ctx, struct crypto_blkcipher **res)
221{
222	struct xdr_netobj	key;
223	int			alg;
224
225	p = simple_get_bytes(p, end, &alg, sizeof(alg));
226	if (IS_ERR(p))
227		goto out_err;
228
229	switch (alg) {
230	case ENCTYPE_DES_CBC_CRC:
231	case ENCTYPE_DES_CBC_MD4:
232	case ENCTYPE_DES_CBC_MD5:
233		/* Map all these key types to ENCTYPE_DES_CBC_RAW */
234		alg = ENCTYPE_DES_CBC_RAW;
235		break;
236	}
237
238	if (!supported_gss_krb5_enctype(alg)) {
239		printk(KERN_WARNING "gss_kerberos_mech: unsupported "
240			"encryption key algorithm %d\n", alg);
241		p = ERR_PTR(-EINVAL);
242		goto out_err;
243	}
244	p = simple_get_netobj(p, end, &key);
245	if (IS_ERR(p))
246		goto out_err;
247
248	*res = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
249							CRYPTO_ALG_ASYNC);
250	if (IS_ERR(*res)) {
251		printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
252			"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
253		*res = NULL;
254		goto out_err_free_key;
255	}
256	if (crypto_blkcipher_setkey(*res, key.data, key.len)) {
257		printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
258			"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
259		goto out_err_free_tfm;
260	}
261
262	kfree(key.data);
263	return p;
264
265out_err_free_tfm:
266	crypto_free_blkcipher(*res);
267out_err_free_key:
268	kfree(key.data);
269	p = ERR_PTR(-EINVAL);
270out_err:
271	return p;
272}
273
274static int
275gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
276{
277	int tmp;
278
279	p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
280	if (IS_ERR(p))
281		goto out_err;
282
283	/* Old format supports only DES!  Any other enctype uses new format */
284	ctx->enctype = ENCTYPE_DES_CBC_RAW;
285
286	ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
287	if (ctx->gk5e == NULL) {
288		p = ERR_PTR(-EINVAL);
289		goto out_err;
290	}
291
292	/* The downcall format was designed before we completely understood
293	 * the uses of the context fields; so it includes some stuff we
294	 * just give some minimal sanity-checking, and some we ignore
295	 * completely (like the next twenty bytes): */
296	if (unlikely(p + 20 > end || p + 20 < p)) {
297		p = ERR_PTR(-EFAULT);
298		goto out_err;
299	}
300	p += 20;
301	p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
302	if (IS_ERR(p))
303		goto out_err;
304	if (tmp != SGN_ALG_DES_MAC_MD5) {
305		p = ERR_PTR(-ENOSYS);
306		goto out_err;
307	}
308	p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
309	if (IS_ERR(p))
310		goto out_err;
311	if (tmp != SEAL_ALG_DES) {
312		p = ERR_PTR(-ENOSYS);
313		goto out_err;
314	}
315	p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
316	if (IS_ERR(p))
317		goto out_err;
318	p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
319	if (IS_ERR(p))
320		goto out_err;
321	p = simple_get_netobj(p, end, &ctx->mech_used);
322	if (IS_ERR(p))
323		goto out_err;
324	p = get_key(p, end, ctx, &ctx->enc);
325	if (IS_ERR(p))
326		goto out_err_free_mech;
327	p = get_key(p, end, ctx, &ctx->seq);
328	if (IS_ERR(p))
329		goto out_err_free_key1;
330	if (p != end) {
331		p = ERR_PTR(-EFAULT);
332		goto out_err_free_key2;
333	}
334
335	return 0;
336
337out_err_free_key2:
338	crypto_free_blkcipher(ctx->seq);
339out_err_free_key1:
340	crypto_free_blkcipher(ctx->enc);
341out_err_free_mech:
342	kfree(ctx->mech_used.data);
343out_err:
344	return PTR_ERR(p);
345}
346
347static struct crypto_blkcipher *
348context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
349{
350	struct crypto_blkcipher *cp;
351
352	cp = crypto_alloc_blkcipher(cname, 0, CRYPTO_ALG_ASYNC);
353	if (IS_ERR(cp)) {
354		dprintk("gss_kerberos_mech: unable to initialize "
355			"crypto algorithm %s\n", cname);
356		return NULL;
357	}
358	if (crypto_blkcipher_setkey(cp, key, ctx->gk5e->keylength)) {
359		dprintk("gss_kerberos_mech: error setting key for "
360			"crypto algorithm %s\n", cname);
361		crypto_free_blkcipher(cp);
362		return NULL;
363	}
364	return cp;
365}
366
367static inline void
368set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
369{
370	cdata[0] = (usage>>24)&0xff;
371	cdata[1] = (usage>>16)&0xff;
372	cdata[2] = (usage>>8)&0xff;
373	cdata[3] = usage&0xff;
374	cdata[4] = seed;
375}
376
377static int
378context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask)
379{
380	struct xdr_netobj c, keyin, keyout;
381	u8 cdata[GSS_KRB5_K5CLENGTH];
382	u32 err;
383
384	c.len = GSS_KRB5_K5CLENGTH;
385	c.data = cdata;
386
387	keyin.data = ctx->Ksess;
388	keyin.len = ctx->gk5e->keylength;
389	keyout.len = ctx->gk5e->keylength;
390
391	/* seq uses the raw key */
392	ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
393					   ctx->Ksess);
394	if (ctx->seq == NULL)
395		goto out_err;
396
397	ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
398					   ctx->Ksess);
399	if (ctx->enc == NULL)
400		goto out_free_seq;
401
402	/* derive cksum */
403	set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
404	keyout.data = ctx->cksum;
405	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
406	if (err) {
407		dprintk("%s: Error %d deriving cksum key\n",
408			__func__, err);
409		goto out_free_enc;
410	}
411
412	return 0;
413
414out_free_enc:
415	crypto_free_blkcipher(ctx->enc);
416out_free_seq:
417	crypto_free_blkcipher(ctx->seq);
418out_err:
419	return -EINVAL;
420}
421
422/*
423 * Note that RC4 depends on deriving keys using the sequence
424 * number or the checksum of a token.  Therefore, the final keys
425 * cannot be calculated until the token is being constructed!
426 */
427static int
428context_derive_keys_rc4(struct krb5_ctx *ctx)
429{
430	struct crypto_hash *hmac;
431	char sigkeyconstant[] = "signaturekey";
432	int slen = strlen(sigkeyconstant) + 1;	/* include null terminator */
433	struct hash_desc desc;
434	struct scatterlist sg[1];
435	int err;
436
437	dprintk("RPC:       %s: entered\n", __func__);
438	/*
439	 * derive cksum (aka Ksign) key
440	 */
441	hmac = crypto_alloc_hash(ctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
442	if (IS_ERR(hmac)) {
443		dprintk("%s: error %ld allocating hash '%s'\n",
444			__func__, PTR_ERR(hmac), ctx->gk5e->cksum_name);
445		err = PTR_ERR(hmac);
446		goto out_err;
447	}
448
449	err = crypto_hash_setkey(hmac, ctx->Ksess, ctx->gk5e->keylength);
450	if (err)
451		goto out_err_free_hmac;
452
453	sg_init_table(sg, 1);
454	sg_set_buf(sg, sigkeyconstant, slen);
455
456	desc.tfm = hmac;
457	desc.flags = 0;
458
459	err = crypto_hash_init(&desc);
460	if (err)
461		goto out_err_free_hmac;
462
463	err = crypto_hash_digest(&desc, sg, slen, ctx->cksum);
464	if (err)
465		goto out_err_free_hmac;
466	/*
467	 * allocate hash, and blkciphers for data and seqnum encryption
468	 */
469	ctx->enc = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
470					  CRYPTO_ALG_ASYNC);
471	if (IS_ERR(ctx->enc)) {
472		err = PTR_ERR(ctx->enc);
473		goto out_err_free_hmac;
474	}
475
476	ctx->seq = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
477					  CRYPTO_ALG_ASYNC);
478	if (IS_ERR(ctx->seq)) {
479		crypto_free_blkcipher(ctx->enc);
480		err = PTR_ERR(ctx->seq);
481		goto out_err_free_hmac;
482	}
483
484	dprintk("RPC:       %s: returning success\n", __func__);
485
486	err = 0;
487
488out_err_free_hmac:
489	crypto_free_hash(hmac);
490out_err:
491	dprintk("RPC:       %s: returning %d\n", __func__, err);
492	return err;
493}
494
495static int
496context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
497{
498	struct xdr_netobj c, keyin, keyout;
499	u8 cdata[GSS_KRB5_K5CLENGTH];
500	u32 err;
501
502	c.len = GSS_KRB5_K5CLENGTH;
503	c.data = cdata;
504
505	keyin.data = ctx->Ksess;
506	keyin.len = ctx->gk5e->keylength;
507	keyout.len = ctx->gk5e->keylength;
508
509	/* initiator seal encryption */
510	set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
511	keyout.data = ctx->initiator_seal;
512	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
513	if (err) {
514		dprintk("%s: Error %d deriving initiator_seal key\n",
515			__func__, err);
516		goto out_err;
517	}
518	ctx->initiator_enc = context_v2_alloc_cipher(ctx,
519						     ctx->gk5e->encrypt_name,
520						     ctx->initiator_seal);
521	if (ctx->initiator_enc == NULL)
522		goto out_err;
523
524	/* acceptor seal encryption */
525	set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
526	keyout.data = ctx->acceptor_seal;
527	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
528	if (err) {
529		dprintk("%s: Error %d deriving acceptor_seal key\n",
530			__func__, err);
531		goto out_free_initiator_enc;
532	}
533	ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
534						    ctx->gk5e->encrypt_name,
535						    ctx->acceptor_seal);
536	if (ctx->acceptor_enc == NULL)
537		goto out_free_initiator_enc;
538
539	/* initiator sign checksum */
540	set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
541	keyout.data = ctx->initiator_sign;
542	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
543	if (err) {
544		dprintk("%s: Error %d deriving initiator_sign key\n",
545			__func__, err);
546		goto out_free_acceptor_enc;
547	}
548
549	/* acceptor sign checksum */
550	set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
551	keyout.data = ctx->acceptor_sign;
552	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
553	if (err) {
554		dprintk("%s: Error %d deriving acceptor_sign key\n",
555			__func__, err);
556		goto out_free_acceptor_enc;
557	}
558
559	/* initiator seal integrity */
560	set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
561	keyout.data = ctx->initiator_integ;
562	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
563	if (err) {
564		dprintk("%s: Error %d deriving initiator_integ key\n",
565			__func__, err);
566		goto out_free_acceptor_enc;
567	}
568
569	/* acceptor seal integrity */
570	set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
571	keyout.data = ctx->acceptor_integ;
572	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
573	if (err) {
574		dprintk("%s: Error %d deriving acceptor_integ key\n",
575			__func__, err);
576		goto out_free_acceptor_enc;
577	}
578
579	switch (ctx->enctype) {
580	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
581	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
582		ctx->initiator_enc_aux =
583			context_v2_alloc_cipher(ctx, "cbc(aes)",
584						ctx->initiator_seal);
585		if (ctx->initiator_enc_aux == NULL)
586			goto out_free_acceptor_enc;
587		ctx->acceptor_enc_aux =
588			context_v2_alloc_cipher(ctx, "cbc(aes)",
589						ctx->acceptor_seal);
590		if (ctx->acceptor_enc_aux == NULL) {
591			crypto_free_blkcipher(ctx->initiator_enc_aux);
592			goto out_free_acceptor_enc;
593		}
594	}
595
596	return 0;
597
598out_free_acceptor_enc:
599	crypto_free_blkcipher(ctx->acceptor_enc);
600out_free_initiator_enc:
601	crypto_free_blkcipher(ctx->initiator_enc);
602out_err:
603	return -EINVAL;
604}
605
606static int
607gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
608		gfp_t gfp_mask)
609{
610	int keylen;
611
612	p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
613	if (IS_ERR(p))
614		goto out_err;
615	ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
616
617	p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
618	if (IS_ERR(p))
619		goto out_err;
620	p = simple_get_bytes(p, end, &ctx->seq_send64, sizeof(ctx->seq_send64));
621	if (IS_ERR(p))
622		goto out_err;
623	/* set seq_send for use by "older" enctypes */
624	ctx->seq_send = ctx->seq_send64;
625	if (ctx->seq_send64 != ctx->seq_send) {
626		dprintk("%s: seq_send64 %lx, seq_send %x overflow?\n", __func__,
627			(unsigned long)ctx->seq_send64, ctx->seq_send);
628		p = ERR_PTR(-EINVAL);
629		goto out_err;
630	}
631	p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
632	if (IS_ERR(p))
633		goto out_err;
634	/* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
635	if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
636		ctx->enctype = ENCTYPE_DES3_CBC_RAW;
637	ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
638	if (ctx->gk5e == NULL) {
639		dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
640			ctx->enctype);
641		p = ERR_PTR(-EINVAL);
642		goto out_err;
643	}
644	keylen = ctx->gk5e->keylength;
645
646	p = simple_get_bytes(p, end, ctx->Ksess, keylen);
647	if (IS_ERR(p))
648		goto out_err;
649
650	if (p != end) {
651		p = ERR_PTR(-EINVAL);
652		goto out_err;
653	}
654
655	ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
656				      gss_kerberos_mech.gm_oid.len, gfp_mask);
657	if (unlikely(ctx->mech_used.data == NULL)) {
658		p = ERR_PTR(-ENOMEM);
659		goto out_err;
660	}
661	ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
662
663	switch (ctx->enctype) {
664	case ENCTYPE_DES3_CBC_RAW:
665		return context_derive_keys_des3(ctx, gfp_mask);
666	case ENCTYPE_ARCFOUR_HMAC:
667		return context_derive_keys_rc4(ctx);
668	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
669	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
670		return context_derive_keys_new(ctx, gfp_mask);
671	default:
672		return -EINVAL;
673	}
674
675out_err:
676	return PTR_ERR(p);
677}
678
679static int
680gss_import_sec_context_kerberos(const void *p, size_t len,
681				struct gss_ctx *ctx_id,
682				time_t *endtime,
683				gfp_t gfp_mask)
684{
685	const void *end = (const void *)((const char *)p + len);
686	struct  krb5_ctx *ctx;
687	int ret;
688
689	ctx = kzalloc(sizeof(*ctx), gfp_mask);
690	if (ctx == NULL)
691		return -ENOMEM;
692
693	if (len == 85)
694		ret = gss_import_v1_context(p, end, ctx);
695	else
696		ret = gss_import_v2_context(p, end, ctx, gfp_mask);
697
698	if (ret == 0) {
699		ctx_id->internal_ctx_id = ctx;
700		if (endtime)
701			*endtime = ctx->endtime;
702	} else
703		kfree(ctx);
704
705	dprintk("RPC:       %s: returning %d\n", __func__, ret);
706	return ret;
707}
708
709static void
710gss_delete_sec_context_kerberos(void *internal_ctx) {
711	struct krb5_ctx *kctx = internal_ctx;
712
713	crypto_free_blkcipher(kctx->seq);
714	crypto_free_blkcipher(kctx->enc);
715	crypto_free_blkcipher(kctx->acceptor_enc);
716	crypto_free_blkcipher(kctx->initiator_enc);
717	crypto_free_blkcipher(kctx->acceptor_enc_aux);
718	crypto_free_blkcipher(kctx->initiator_enc_aux);
719	kfree(kctx->mech_used.data);
720	kfree(kctx);
721}
722
723static const struct gss_api_ops gss_kerberos_ops = {
724	.gss_import_sec_context	= gss_import_sec_context_kerberos,
725	.gss_get_mic		= gss_get_mic_kerberos,
726	.gss_verify_mic		= gss_verify_mic_kerberos,
727	.gss_wrap		= gss_wrap_kerberos,
728	.gss_unwrap		= gss_unwrap_kerberos,
729	.gss_delete_sec_context	= gss_delete_sec_context_kerberos,
730};
731
732static struct pf_desc gss_kerberos_pfs[] = {
733	[0] = {
734		.pseudoflavor = RPC_AUTH_GSS_KRB5,
735		.qop = GSS_C_QOP_DEFAULT,
736		.service = RPC_GSS_SVC_NONE,
737		.name = "krb5",
738	},
739	[1] = {
740		.pseudoflavor = RPC_AUTH_GSS_KRB5I,
741		.qop = GSS_C_QOP_DEFAULT,
742		.service = RPC_GSS_SVC_INTEGRITY,
743		.name = "krb5i",
744	},
745	[2] = {
746		.pseudoflavor = RPC_AUTH_GSS_KRB5P,
747		.qop = GSS_C_QOP_DEFAULT,
748		.service = RPC_GSS_SVC_PRIVACY,
749		.name = "krb5p",
750	},
751};
752
753MODULE_ALIAS("rpc-auth-gss-krb5");
754MODULE_ALIAS("rpc-auth-gss-krb5i");
755MODULE_ALIAS("rpc-auth-gss-krb5p");
756MODULE_ALIAS("rpc-auth-gss-390003");
757MODULE_ALIAS("rpc-auth-gss-390004");
758MODULE_ALIAS("rpc-auth-gss-390005");
759MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
760
761static struct gss_api_mech gss_kerberos_mech = {
762	.gm_name	= "krb5",
763	.gm_owner	= THIS_MODULE,
764	.gm_oid		= { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
765	.gm_ops		= &gss_kerberos_ops,
766	.gm_pf_num	= ARRAY_SIZE(gss_kerberos_pfs),
767	.gm_pfs		= gss_kerberos_pfs,
768	.gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
769};
770
771static int __init init_kerberos_module(void)
772{
773	int status;
774
775	status = gss_mech_register(&gss_kerberos_mech);
776	if (status)
777		printk("Failed to register kerberos gss mechanism!\n");
778	return status;
779}
780
781static void __exit cleanup_kerberos_module(void)
782{
783	gss_mech_unregister(&gss_kerberos_mech);
784}
785
786MODULE_LICENSE("GPL");
787module_init(init_kerberos_module);
788module_exit(cleanup_kerberos_module);
789