1 /* SCTP kernel implementation
2  * (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
3  *
4  * This file is part of the SCTP kernel implementation
5  *
6  * This SCTP implementation is free software;
7  * you can redistribute it and/or modify it under the terms of
8  * the GNU General Public License as published by
9  * the Free Software Foundation; either version 2, or (at your option)
10  * any later version.
11  *
12  * This SCTP implementation is distributed in the hope that it
13  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
14  *                 ************************
15  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16  * See the GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with GNU CC; see the file COPYING.  If not, see
20  * <http://www.gnu.org/licenses/>.
21  *
22  * Please send any bug reports or fixes you make to the
23  * email address(es):
24  *    lksctp developers <linux-sctp@vger.kernel.org>
25  *
26  * Written or modified by:
27  *   Vlad Yasevich     <vladislav.yasevich@hp.com>
28  */
29 
30 #ifndef __sctp_auth_h__
31 #define __sctp_auth_h__
32 
33 #include <linux/list.h>
34 #include <linux/refcount.h>
35 
36 struct sctp_endpoint;
37 struct sctp_association;
38 struct sctp_authkey;
39 struct sctp_hmacalgo;
40 struct crypto_shash;
41 
42 /*
43  * Define a generic struct that will hold all the info
44  * necessary for an HMAC transform
45  */
46 struct sctp_hmac {
47 	__u16 hmac_id;		/* one of the above ids */
48 	char *hmac_name;	/* name for loading */
49 	__u16 hmac_len;		/* length of the signature */
50 };
51 
52 /* This is generic structure that containst authentication bytes used
53  * as keying material.  It's a what is referred to as byte-vector all
54  * over SCTP-AUTH
55  */
56 struct sctp_auth_bytes {
57 	refcount_t refcnt;
58 	__u32 len;
59 	__u8  data[];
60 };
61 
62 /* Definition for a shared key, weather endpoint or association */
63 struct sctp_shared_key {
64 	struct list_head key_list;
65 	struct sctp_auth_bytes *key;
66 	refcount_t refcnt;
67 	__u16 key_id;
68 	__u8 deactivated;
69 };
70 
71 #define key_for_each(__key, __list_head) \
72 	list_for_each_entry(__key, __list_head, key_list)
73 
74 #define key_for_each_safe(__key, __tmp, __list_head) \
75 	list_for_each_entry_safe(__key, __tmp, __list_head, key_list)
76 
sctp_auth_key_hold(struct sctp_auth_bytes * key)77 static inline void sctp_auth_key_hold(struct sctp_auth_bytes *key)
78 {
79 	if (!key)
80 		return;
81 
82 	refcount_inc(&key->refcnt);
83 }
84 
85 void sctp_auth_key_put(struct sctp_auth_bytes *key);
86 struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp);
87 void sctp_auth_destroy_keys(struct list_head *keys);
88 int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp);
89 struct sctp_shared_key *sctp_auth_get_shkey(
90 				const struct sctp_association *asoc,
91 				__u16 key_id);
92 int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
93 				struct sctp_association *asoc,
94 				gfp_t gfp);
95 int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp);
96 void sctp_auth_destroy_hmacs(struct crypto_shash *auth_hmacs[]);
97 struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id);
98 struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc);
99 void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
100 				     struct sctp_hmac_algo_param *hmacs);
101 int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
102 				    __be16 hmac_id);
103 int sctp_auth_send_cid(enum sctp_cid chunk,
104 		       const struct sctp_association *asoc);
105 int sctp_auth_recv_cid(enum sctp_cid chunk,
106 		       const struct sctp_association *asoc);
107 void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
108 			      struct sk_buff *skb, struct sctp_auth_chunk *auth,
109 			      struct sctp_shared_key *ep_key, gfp_t gfp);
110 void sctp_auth_shkey_release(struct sctp_shared_key *sh_key);
111 void sctp_auth_shkey_hold(struct sctp_shared_key *sh_key);
112 
113 /* API Helpers */
114 int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id);
115 int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
116 			    struct sctp_hmacalgo *hmacs);
117 int sctp_auth_set_key(struct sctp_endpoint *ep, struct sctp_association *asoc,
118 		      struct sctp_authkey *auth_key);
119 int sctp_auth_set_active_key(struct sctp_endpoint *ep,
120 			     struct sctp_association *asoc, __u16 key_id);
121 int sctp_auth_del_key_id(struct sctp_endpoint *ep,
122 			 struct sctp_association *asoc, __u16 key_id);
123 int sctp_auth_deact_key_id(struct sctp_endpoint *ep,
124 			   struct sctp_association *asoc, __u16 key_id);
125 
126 #endif
127