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	[SCTP]: Implement SCTP-AUTH internals
This patch implements the internals operations of the AUTH, such as key computation and storage. It also adds necessary variables to the SCTP data structures. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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								include/net/sctp/auth.h
									
									
									
									
									
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								include/net/sctp/auth.h
									
									
									
									
									
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			@ -0,0 +1,112 @@
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/* SCTP kernel reference Implementation
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 * (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
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 *
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 * This file is part of the SCTP kernel reference Implementation
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 *
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 * The SCTP reference implementation is free software;
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 * you can redistribute it and/or modify it under the terms of
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 * the GNU General Public License as published by
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 * the Free Software Foundation; either version 2, or (at your option)
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 * any later version.
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 *
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 * The SCTP reference implementation is distributed in the hope that it
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 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
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 *                 ************************
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 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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 * See the GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with GNU CC; see the file COPYING.  If not, write to
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 * the Free Software Foundation, 59 Temple Place - Suite 330,
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 * Boston, MA 02111-1307, USA.
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 *
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 * Please send any bug reports or fixes you make to the
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 * email address(es):
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 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
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 *
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 * Or submit a bug report through the following website:
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 *    http://www.sf.net/projects/lksctp
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 *
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 * Written or modified by:
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 *   Vlad Yasevich     <vladislav.yasevich@hp.com>
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 *
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 * Any bugs reported given to us we will try to fix... any fixes shared will
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 * be incorporated into the next SCTP release.
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 */
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#ifndef __sctp_auth_h__
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#define __sctp_auth_h__
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#include <linux/list.h>
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#include <linux/crypto.h>
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struct sctp_endpoint;
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struct sctp_association;
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struct sctp_authkey;
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/*
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 * Define a generic struct that will hold all the info
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 * necessary for an HMAC transform
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 */
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struct sctp_hmac {
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	__u16 hmac_id;		/* one of the above ids */
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	char *hmac_name;	/* name for loading */
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	__u16 hmac_len;		/* length of the signature */
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};
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/* This is generic structure that containst authentication bytes used
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 * as keying material.  It's a what is referred to as byte-vector all
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 * over SCTP-AUTH
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 */
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struct sctp_auth_bytes {
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	atomic_t refcnt;
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	__u32 len;
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	__u8  data[];
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};
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/* Definition for a shared key, weather endpoint or association */
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struct sctp_shared_key {
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	struct list_head key_list;
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	__u16 key_id;
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	struct sctp_auth_bytes *key;
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};
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#define key_for_each(__key, __list_head) \
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	list_for_each_entry(__key, __list_head, key_list)
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#define key_for_each_safe(__key, __tmp, __list_head) \
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	list_for_each_entry_safe(__key, __tmp, __list_head, key_list)
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static inline void sctp_auth_key_hold(struct sctp_auth_bytes *key)
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{
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	if (!key)
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		return;
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	atomic_inc(&key->refcnt);
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}
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void sctp_auth_key_put(struct sctp_auth_bytes *key);
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struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp);
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void sctp_auth_shkey_free(struct sctp_shared_key *sh_key);
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void sctp_auth_destroy_keys(struct list_head *keys);
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int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp);
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struct sctp_shared_key *sctp_auth_get_shkey(
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				const struct sctp_association *asoc,
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				__u16 key_id);
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int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
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				struct sctp_association *asoc,
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				gfp_t gfp);
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int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp);
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void sctp_auth_destroy_hmacs(struct crypto_hash *auth_hmacs[]);
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struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id);
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struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc);
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void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
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				     struct sctp_hmac_algo_param *hmacs);
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int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
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				    __u16 hmac_id);
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int sctp_auth_send_cid(sctp_cid_t chunk, const struct sctp_association *asoc);
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int sctp_auth_recv_cid(sctp_cid_t chunk, const struct sctp_association *asoc);
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void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
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			    struct sk_buff *skb,
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			    struct sctp_auth_chunk *auth, gfp_t gfp);
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#endif
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			@ -64,12 +64,18 @@ enum { SCTP_DEFAULT_INSTREAMS = SCTP_MAX_STREAM };
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#define SCTP_CID_MAX			SCTP_CID_ASCONF_ACK
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#define SCTP_NUM_BASE_CHUNK_TYPES	(SCTP_CID_BASE_MAX + 1)
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#define SCTP_NUM_CHUNK_TYPES		(SCTP_NUM_BASE_CHUNKTYPES + 2)
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#define SCTP_NUM_ADDIP_CHUNK_TYPES	2
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#define SCTP_NUM_PRSCTP_CHUNK_TYPES	1
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#define SCTP_NUM_AUTH_CHUNK_TYPES	1
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#define SCTP_NUM_CHUNK_TYPES		(SCTP_NUM_BASE_CHUNK_TYPES + \
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					 SCTP_NUM_ADDIP_CHUNK_TYPES +\
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					 SCTP_NUM_PRSCTP_CHUNK_TYPES +\
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					 SCTP_NUM_AUTH_CHUNK_TYPES)
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/* These are the different flavours of event.  */
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typedef enum {
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			@ -409,4 +415,45 @@ typedef enum {
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	SCTP_LOWER_CWND_INACTIVE,
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} sctp_lower_cwnd_t;
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/* SCTP-AUTH Necessary constants */
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/* SCTP-AUTH, Section 3.3
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 *
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 *  The following Table 2 shows the currently defined values for HMAC
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 *  identifiers.
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 *
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 *  +-----------------+--------------------------+
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 *  | HMAC Identifier | Message Digest Algorithm |
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 *  +-----------------+--------------------------+
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 *  | 0               | Reserved                 |
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 *  | 1               | SHA-1 defined in [8]     |
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 *  | 2               | Reserved                 |
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 *  | 3               | SHA-256 defined in [8]   |
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 *  +-----------------+--------------------------+
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 */
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enum {
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	SCTP_AUTH_HMAC_ID_RESERVED_0,
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	SCTP_AUTH_HMAC_ID_SHA1,
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	SCTP_AUTH_HMAC_ID_RESERVED_2,
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	SCTP_AUTH_HMAC_ID_SHA256
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};
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#define SCTP_AUTH_HMAC_ID_MAX	SCTP_AUTH_HMAC_ID_SHA256
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#define SCTP_AUTH_NUM_HMACS (SCTP_AUTH_HMAC_ID_SHA256 + 1)
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#define SCTP_SHA1_SIG_SIZE 20
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#define SCTP_SHA256_SIG_SIZE 32
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/*  SCTP-AUTH, Section 3.2
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 *     The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks
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 *     MUST NOT be listed in the CHUNKS parameter
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 */
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#define SCTP_NUM_NOAUTH_CHUNKS	4
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#define SCTP_AUTH_MAX_CHUNKS	(SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS)
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/* SCTP-AUTH Section 6.1
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 * The RANDOM parameter MUST contain a 32 byte random number.
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 */
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#define SCTP_AUTH_RANDOM_LENGTH 32
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#endif /* __sctp_constants_h__ */
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			@ -341,6 +341,7 @@ extern atomic_t sctp_dbg_objcnt_bind_bucket;
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extern atomic_t sctp_dbg_objcnt_addr;
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extern atomic_t sctp_dbg_objcnt_ssnmap;
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extern atomic_t sctp_dbg_objcnt_datamsg;
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extern atomic_t sctp_dbg_objcnt_keys;
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/* Macros to atomically increment/decrement objcnt counters.  */
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#define SCTP_DBG_OBJCNT_INC(name) \
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			@ -64,6 +64,7 @@
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#include <linux/skbuff.h>	/* We need sk_buff_head. */
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#include <linux/workqueue.h>	/* We need tq_struct.	 */
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#include <linux/sctp.h>		/* We need sctp* header structs.  */
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#include <net/sctp/auth.h>	/* We need auth specific structs */
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/* A convenience structure for handling sockaddr structures.
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 * We should wean ourselves off this.
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			@ -216,6 +217,9 @@ extern struct sctp_globals {
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	/* Flag to indicate if PR-SCTP is enabled. */
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	int prsctp_enable;
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	/* Flag to idicate if SCTP-AUTH is enabled */
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	int auth_enable;
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} sctp_globals;
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#define sctp_rto_initial		(sctp_globals.rto_initial)
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			@ -248,6 +252,7 @@ extern struct sctp_globals {
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#define sctp_local_addr_lock		(sctp_globals.addr_list_lock)
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#define sctp_addip_enable		(sctp_globals.addip_enable)
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#define sctp_prsctp_enable		(sctp_globals.prsctp_enable)
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#define sctp_auth_enable		(sctp_globals.auth_enable)
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/* SCTP Socket type: UDP or TCP style. */
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typedef enum {
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			@ -397,6 +402,9 @@ struct sctp_cookie {
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	__u32 adaptation_ind;
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	__u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
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	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS + 2];
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	__u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
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	/* This is a shim for my peer's INIT packet, followed by
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	 * a copy of the raw address list of the association.
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			@ -441,6 +449,9 @@ union sctp_params {
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	union sctp_addr_param *addr;
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	struct sctp_adaptation_ind_param *aind;
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	struct sctp_supported_ext_param *ext;
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	struct sctp_random_param *random;
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	struct sctp_chunks_param *chunks;
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	struct sctp_hmac_algo_param *hmac_algo;
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};
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/* RFC 2960.  Section 3.3.5 Heartbeat.
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			@ -679,6 +690,7 @@ struct sctp_chunk {
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		struct sctp_errhdr *err_hdr;
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		struct sctp_addiphdr *addip_hdr;
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		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
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		struct sctp_authhdr *auth_hdr;
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	} subh;
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	__u8 *chunk_end;
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			@ -724,6 +736,7 @@ struct sctp_chunk {
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	__s8 fast_retransmit;	 /* Is this chunk fast retransmitted? */
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	__u8 tsn_missing_report; /* Data chunk missing counter. */
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	__u8 data_accepted; 	/* At least 1 chunk in this packet accepted */
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	__u8 auth;		/* IN: was auth'ed | OUT: needs auth */
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};
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void sctp_chunk_hold(struct sctp_chunk *);
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			@ -773,16 +786,22 @@ struct sctp_packet {
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	 */
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	struct sctp_transport *transport;
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	/* This packet contains a COOKIE-ECHO chunk. */
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	char has_cookie_echo;
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	/* pointer to the auth chunk for this packet */
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	struct sctp_chunk *auth;
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	/* This packet containsa SACK chunk. */
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	char has_sack;
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	/* This packet contains a COOKIE-ECHO chunk. */
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	__u8 has_cookie_echo;
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	/* This packet contains a SACK chunk. */
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	__u8 has_sack;
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	/* This packet contains an AUTH chunk */
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	__u8 has_auth;
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	/* SCTP cannot fragment this packet. So let ip fragment it. */
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	char ipfragok;
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	__u8 ipfragok;
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	int malloced;
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	__u8 malloced;
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};
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struct sctp_packet *sctp_packet_init(struct sctp_packet *,
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			@ -1291,6 +1310,21 @@ struct sctp_endpoint {
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	/* rcvbuf acct. policy.	*/
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	__u32 rcvbuf_policy;
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	/* SCTP AUTH: array of the HMACs that will be allocated
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	 * we need this per association so that we don't serialize
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	 */
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	struct crypto_hash **auth_hmacs;
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	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
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	 struct sctp_hmac_algo_param *auth_hmacs_list;
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	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
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	struct sctp_chunks_param *auth_chunk_list;
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	/* SCTP-AUTH: endpoint shared keys */
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	struct list_head endpoint_shared_keys;
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	__u16 active_key_id;
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};
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/* Recover the outter endpoint structure. */
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| 
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			@ -1497,6 +1531,7 @@ struct sctp_association {
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		__u8	hostname_address;/* Peer understands DNS addresses? */
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		__u8    asconf_capable;  /* Does peer support ADDIP? */
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		__u8    prsctp_capable;  /* Can peer do PR-SCTP? */
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		__u8	auth_capable;	 /* Is peer doing SCTP-AUTH? */
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		__u32   adaptation_ind;	 /* Adaptation Code point. */
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| 
						 | 
				
			
			@ -1514,6 +1549,14 @@ struct sctp_association {
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		 * Initial TSN Value minus 1
 | 
			
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		 */
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		__u32 addip_serial;
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		/* SCTP-AUTH: We need to know pears random number, hmac list
 | 
			
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		 * and authenticated chunk list.  All that is part of the
 | 
			
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		 * cookie and these are just pointers to those locations
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		 */
 | 
			
		||||
		sctp_random_param_t *peer_random;
 | 
			
		||||
		sctp_chunks_param_t *peer_chunks;
 | 
			
		||||
		sctp_hmac_algo_param_t *peer_hmacs;
 | 
			
		||||
	} peer;
 | 
			
		||||
 | 
			
		||||
	/* State       : A state variable indicating what state the
 | 
			
		||||
| 
						 | 
				
			
			@ -1797,6 +1840,24 @@ struct sctp_association {
 | 
			
		|||
	 */
 | 
			
		||||
	__u32 addip_serial;
 | 
			
		||||
 | 
			
		||||
	/* SCTP AUTH: list of the endpoint shared keys.  These
 | 
			
		||||
	 * keys are provided out of band by the user applicaton
 | 
			
		||||
	 * and can't change during the lifetime of the association
 | 
			
		||||
	 */
 | 
			
		||||
	struct list_head endpoint_shared_keys;
 | 
			
		||||
 | 
			
		||||
	/* SCTP AUTH:
 | 
			
		||||
	 * The current generated assocaition shared key (secret)
 | 
			
		||||
	 */
 | 
			
		||||
	struct sctp_auth_bytes *asoc_shared_key;
 | 
			
		||||
 | 
			
		||||
	/* SCTP AUTH: hmac id of the first peer requested algorithm
 | 
			
		||||
	 * that we support.
 | 
			
		||||
	 */
 | 
			
		||||
	__u16 default_hmac_id;
 | 
			
		||||
 | 
			
		||||
	__u16 active_key_id;
 | 
			
		||||
 | 
			
		||||
	/* Need to send an ECNE Chunk? */
 | 
			
		||||
	char need_ecne;
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -9,7 +9,8 @@ sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \
 | 
			
		|||
	  transport.o chunk.o sm_make_chunk.o ulpevent.o \
 | 
			
		||||
	  inqueue.o outqueue.o ulpqueue.o command.o \
 | 
			
		||||
	  tsnmap.o bind_addr.o socket.o primitive.o \
 | 
			
		||||
	  output.o input.o debug.o ssnmap.o proc.o crc32c.o
 | 
			
		||||
	  output.o input.o debug.o ssnmap.o proc.o crc32c.o \
 | 
			
		||||
	  auth.o
 | 
			
		||||
 | 
			
		||||
sctp-$(CONFIG_SCTP_DBG_OBJCNT) += objcnt.o
 | 
			
		||||
sctp-$(CONFIG_SYSCTL) += sysctl.o
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
							
								
								
									
										745
									
								
								net/sctp/auth.c
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										745
									
								
								net/sctp/auth.c
									
									
									
									
									
										Normal file
									
								
							| 
						 | 
				
			
			@ -0,0 +1,745 @@
 | 
			
		|||
/* SCTP kernel reference Implementation
 | 
			
		||||
 * (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
 | 
			
		||||
 *
 | 
			
		||||
 * This file is part of the SCTP kernel reference Implementation
 | 
			
		||||
 *
 | 
			
		||||
 * The SCTP reference implementation is free software;
 | 
			
		||||
 * you can redistribute it and/or modify it under the terms of
 | 
			
		||||
 * the GNU General Public License as published by
 | 
			
		||||
 * the Free Software Foundation; either version 2, or (at your option)
 | 
			
		||||
 * any later version.
 | 
			
		||||
 *
 | 
			
		||||
 * The SCTP reference implementation is distributed in the hope that it
 | 
			
		||||
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 | 
			
		||||
 *                 ************************
 | 
			
		||||
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 | 
			
		||||
 * See the GNU General Public License for more details.
 | 
			
		||||
 *
 | 
			
		||||
 * You should have received a copy of the GNU General Public License
 | 
			
		||||
 * along with GNU CC; see the file COPYING.  If not, write to
 | 
			
		||||
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 | 
			
		||||
 * Boston, MA 02111-1307, USA.
 | 
			
		||||
 *
 | 
			
		||||
 * Please send any bug reports or fixes you make to the
 | 
			
		||||
 * email address(es):
 | 
			
		||||
 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 | 
			
		||||
 *
 | 
			
		||||
 * Or submit a bug report through the following website:
 | 
			
		||||
 *    http://www.sf.net/projects/lksctp
 | 
			
		||||
 *
 | 
			
		||||
 * Written or modified by:
 | 
			
		||||
 *   Vlad Yasevich     <vladislav.yasevich@hp.com>
 | 
			
		||||
 *
 | 
			
		||||
 * Any bugs reported given to us we will try to fix... any fixes shared will
 | 
			
		||||
 * be incorporated into the next SCTP release.
 | 
			
		||||
 */
 | 
			
		||||
 | 
			
		||||
#include <linux/types.h>
 | 
			
		||||
#include <linux/crypto.h>
 | 
			
		||||
#include <linux/scatterlist.h>
 | 
			
		||||
#include <net/sctp/sctp.h>
 | 
			
		||||
#include <net/sctp/auth.h>
 | 
			
		||||
 | 
			
		||||
static struct sctp_hmac sctp_hmac_list[SCTP_AUTH_NUM_HMACS] = {
 | 
			
		||||
	{
 | 
			
		||||
		/* id 0 is reserved.  as all 0 */
 | 
			
		||||
		.hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_0,
 | 
			
		||||
	},
 | 
			
		||||
	{
 | 
			
		||||
		.hmac_id = SCTP_AUTH_HMAC_ID_SHA1,
 | 
			
		||||
		.hmac_name="hmac(sha1)",
 | 
			
		||||
		.hmac_len = SCTP_SHA1_SIG_SIZE,
 | 
			
		||||
	},
 | 
			
		||||
	{
 | 
			
		||||
		/* id 2 is reserved as well */
 | 
			
		||||
		.hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_2,
 | 
			
		||||
	},
 | 
			
		||||
	{
 | 
			
		||||
		.hmac_id = SCTP_AUTH_HMAC_ID_SHA256,
 | 
			
		||||
		.hmac_name="hmac(sha256)",
 | 
			
		||||
		.hmac_len = SCTP_SHA256_SIG_SIZE,
 | 
			
		||||
	}
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
void sctp_auth_key_put(struct sctp_auth_bytes *key)
 | 
			
		||||
{
 | 
			
		||||
	if (!key)
 | 
			
		||||
		return;
 | 
			
		||||
 | 
			
		||||
	if (atomic_dec_and_test(&key->refcnt)) {
 | 
			
		||||
		kfree(key);
 | 
			
		||||
		SCTP_DBG_OBJCNT_DEC(keys);
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Create a new key structure of a given length */
 | 
			
		||||
static struct sctp_auth_bytes *sctp_auth_create_key(__u32 key_len, gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_auth_bytes *key;
 | 
			
		||||
 | 
			
		||||
	/* Allocate the shared key */
 | 
			
		||||
	key = kmalloc(sizeof(struct sctp_auth_bytes) + key_len, gfp);
 | 
			
		||||
	if (!key)
 | 
			
		||||
		return NULL;
 | 
			
		||||
 | 
			
		||||
	key->len = key_len;
 | 
			
		||||
	atomic_set(&key->refcnt, 1);
 | 
			
		||||
	SCTP_DBG_OBJCNT_INC(keys);
 | 
			
		||||
 | 
			
		||||
	return key;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Create a new shared key container with a give key id */
 | 
			
		||||
struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_shared_key *new;
 | 
			
		||||
 | 
			
		||||
	/* Allocate the shared key container */
 | 
			
		||||
	new = kzalloc(sizeof(struct sctp_shared_key), gfp);
 | 
			
		||||
	if (!new)
 | 
			
		||||
		return NULL;
 | 
			
		||||
 | 
			
		||||
	INIT_LIST_HEAD(&new->key_list);
 | 
			
		||||
	new->key_id = key_id;
 | 
			
		||||
 | 
			
		||||
	return new;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Free the shared key stucture */
 | 
			
		||||
void sctp_auth_shkey_free(struct sctp_shared_key *sh_key)
 | 
			
		||||
{
 | 
			
		||||
	BUG_ON(!list_empty(&sh_key->key_list));
 | 
			
		||||
	sctp_auth_key_put(sh_key->key);
 | 
			
		||||
	sh_key->key = NULL;
 | 
			
		||||
	kfree(sh_key);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Destory the entire key list.  This is done during the
 | 
			
		||||
 * associon and endpoint free process.
 | 
			
		||||
 */
 | 
			
		||||
void sctp_auth_destroy_keys(struct list_head *keys)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_shared_key *ep_key;
 | 
			
		||||
	struct sctp_shared_key *tmp;
 | 
			
		||||
 | 
			
		||||
	if (list_empty(keys))
 | 
			
		||||
		return;
 | 
			
		||||
 | 
			
		||||
	key_for_each_safe(ep_key, tmp, keys) {
 | 
			
		||||
		list_del_init(&ep_key->key_list);
 | 
			
		||||
		sctp_auth_shkey_free(ep_key);
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Compare two byte vectors as numbers.  Return values
 | 
			
		||||
 * are:
 | 
			
		||||
 * 	  0 - vectors are equal
 | 
			
		||||
 * 	< 0 - vector 1 is smaller then vector2
 | 
			
		||||
 * 	> 0 - vector 1 is greater then vector2
 | 
			
		||||
 *
 | 
			
		||||
 * Algorithm is:
 | 
			
		||||
 * 	This is performed by selecting the numerically smaller key vector...
 | 
			
		||||
 *	If the key vectors are equal as numbers but differ in length ...
 | 
			
		||||
 *	the shorter vector is considered smaller
 | 
			
		||||
 *
 | 
			
		||||
 * Examples (with small values):
 | 
			
		||||
 * 	000123456789 > 123456789 (first number is longer)
 | 
			
		||||
 * 	000123456789 < 234567891 (second number is larger numerically)
 | 
			
		||||
 * 	123456789 > 2345678 	 (first number is both larger & longer)
 | 
			
		||||
 */
 | 
			
		||||
static int sctp_auth_compare_vectors(struct sctp_auth_bytes *vector1,
 | 
			
		||||
			      struct sctp_auth_bytes *vector2)
 | 
			
		||||
{
 | 
			
		||||
	int diff;
 | 
			
		||||
	int i;
 | 
			
		||||
	const __u8 *longer;
 | 
			
		||||
 | 
			
		||||
	diff = vector1->len - vector2->len;
 | 
			
		||||
	if (diff) {
 | 
			
		||||
		longer = (diff > 0) ? vector1->data : vector2->data;
 | 
			
		||||
 | 
			
		||||
		/* Check to see if the longer number is
 | 
			
		||||
		 * lead-zero padded.  If it is not, it
 | 
			
		||||
		 * is automatically larger numerically.
 | 
			
		||||
		 */
 | 
			
		||||
		for (i = 0; i < abs(diff); i++ ) {
 | 
			
		||||
			if (longer[i] != 0)
 | 
			
		||||
				return diff;
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	/* lengths are the same, compare numbers */
 | 
			
		||||
	return memcmp(vector1->data, vector2->data, vector1->len);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Create a key vector as described in SCTP-AUTH, Section 6.1
 | 
			
		||||
 *    The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO
 | 
			
		||||
 *    parameter sent by each endpoint are concatenated as byte vectors.
 | 
			
		||||
 *    These parameters include the parameter type, parameter length, and
 | 
			
		||||
 *    the parameter value, but padding is omitted; all padding MUST be
 | 
			
		||||
 *    removed from this concatenation before proceeding with further
 | 
			
		||||
 *    computation of keys.  Parameters which were not sent are simply
 | 
			
		||||
 *    omitted from the concatenation process.  The resulting two vectors
 | 
			
		||||
 *    are called the two key vectors.
 | 
			
		||||
 */
 | 
			
		||||
static struct sctp_auth_bytes *sctp_auth_make_key_vector(
 | 
			
		||||
			sctp_random_param_t *random,
 | 
			
		||||
			sctp_chunks_param_t *chunks,
 | 
			
		||||
			sctp_hmac_algo_param_t *hmacs,
 | 
			
		||||
			gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_auth_bytes *new;
 | 
			
		||||
	__u32	len;
 | 
			
		||||
	__u32	offset = 0;
 | 
			
		||||
 | 
			
		||||
	len = ntohs(random->param_hdr.length) + ntohs(hmacs->param_hdr.length);
 | 
			
		||||
        if (chunks)
 | 
			
		||||
		len += ntohs(chunks->param_hdr.length);
 | 
			
		||||
 | 
			
		||||
	new = kmalloc(sizeof(struct sctp_auth_bytes) + len, gfp);
 | 
			
		||||
	if (!new)
 | 
			
		||||
		return NULL;
 | 
			
		||||
 | 
			
		||||
	new->len = len;
 | 
			
		||||
 | 
			
		||||
	memcpy(new->data, random, ntohs(random->param_hdr.length));
 | 
			
		||||
	offset += ntohs(random->param_hdr.length);
 | 
			
		||||
 | 
			
		||||
	if (chunks) {
 | 
			
		||||
		memcpy(new->data + offset, chunks,
 | 
			
		||||
			ntohs(chunks->param_hdr.length));
 | 
			
		||||
		offset += ntohs(chunks->param_hdr.length);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	memcpy(new->data + offset, hmacs, ntohs(hmacs->param_hdr.length));
 | 
			
		||||
 | 
			
		||||
	return new;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
/* Make a key vector based on our local parameters */
 | 
			
		||||
struct sctp_auth_bytes *sctp_auth_make_local_vector(
 | 
			
		||||
				    const struct sctp_association *asoc,
 | 
			
		||||
				    gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	return sctp_auth_make_key_vector(
 | 
			
		||||
				    (sctp_random_param_t*)asoc->c.auth_random,
 | 
			
		||||
				    (sctp_chunks_param_t*)asoc->c.auth_chunks,
 | 
			
		||||
				    (sctp_hmac_algo_param_t*)asoc->c.auth_hmacs,
 | 
			
		||||
				    gfp);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Make a key vector based on peer's parameters */
 | 
			
		||||
struct sctp_auth_bytes *sctp_auth_make_peer_vector(
 | 
			
		||||
				    const struct sctp_association *asoc,
 | 
			
		||||
				    gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	return sctp_auth_make_key_vector(asoc->peer.peer_random,
 | 
			
		||||
					 asoc->peer.peer_chunks,
 | 
			
		||||
					 asoc->peer.peer_hmacs,
 | 
			
		||||
					 gfp);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
/* Set the value of the association shared key base on the parameters
 | 
			
		||||
 * given.  The algorithm is:
 | 
			
		||||
 *    From the endpoint pair shared keys and the key vectors the
 | 
			
		||||
 *    association shared keys are computed.  This is performed by selecting
 | 
			
		||||
 *    the numerically smaller key vector and concatenating it to the
 | 
			
		||||
 *    endpoint pair shared key, and then concatenating the numerically
 | 
			
		||||
 *    larger key vector to that.  The result of the concatenation is the
 | 
			
		||||
 *    association shared key.
 | 
			
		||||
 */
 | 
			
		||||
static struct sctp_auth_bytes *sctp_auth_asoc_set_secret(
 | 
			
		||||
			struct sctp_shared_key *ep_key,
 | 
			
		||||
			struct sctp_auth_bytes *first_vector,
 | 
			
		||||
			struct sctp_auth_bytes *last_vector,
 | 
			
		||||
			gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_auth_bytes *secret;
 | 
			
		||||
	__u32 offset = 0;
 | 
			
		||||
	__u32 auth_len;
 | 
			
		||||
 | 
			
		||||
	auth_len = first_vector->len + last_vector->len;
 | 
			
		||||
	if (ep_key->key)
 | 
			
		||||
		auth_len += ep_key->key->len;
 | 
			
		||||
 | 
			
		||||
	secret = sctp_auth_create_key(auth_len, gfp);
 | 
			
		||||
	if (!secret)
 | 
			
		||||
		return NULL;
 | 
			
		||||
 | 
			
		||||
	if (ep_key->key) {
 | 
			
		||||
		memcpy(secret->data, ep_key->key->data, ep_key->key->len);
 | 
			
		||||
		offset += ep_key->key->len;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	memcpy(secret->data + offset, first_vector->data, first_vector->len);
 | 
			
		||||
	offset += first_vector->len;
 | 
			
		||||
 | 
			
		||||
	memcpy(secret->data + offset, last_vector->data, last_vector->len);
 | 
			
		||||
 | 
			
		||||
	return secret;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Create an association shared key.  Follow the algorithm
 | 
			
		||||
 * described in SCTP-AUTH, Section 6.1
 | 
			
		||||
 */
 | 
			
		||||
static struct sctp_auth_bytes *sctp_auth_asoc_create_secret(
 | 
			
		||||
				 const struct sctp_association *asoc,
 | 
			
		||||
				 struct sctp_shared_key *ep_key,
 | 
			
		||||
				 gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_auth_bytes *local_key_vector;
 | 
			
		||||
	struct sctp_auth_bytes *peer_key_vector;
 | 
			
		||||
	struct sctp_auth_bytes	*first_vector,
 | 
			
		||||
				*last_vector;
 | 
			
		||||
	struct sctp_auth_bytes	*secret = NULL;
 | 
			
		||||
	int	cmp;
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
	/* Now we need to build the key vectors
 | 
			
		||||
	 * SCTP-AUTH , Section 6.1
 | 
			
		||||
	 *    The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO
 | 
			
		||||
	 *    parameter sent by each endpoint are concatenated as byte vectors.
 | 
			
		||||
	 *    These parameters include the parameter type, parameter length, and
 | 
			
		||||
	 *    the parameter value, but padding is omitted; all padding MUST be
 | 
			
		||||
	 *    removed from this concatenation before proceeding with further
 | 
			
		||||
	 *    computation of keys.  Parameters which were not sent are simply
 | 
			
		||||
	 *    omitted from the concatenation process.  The resulting two vectors
 | 
			
		||||
	 *    are called the two key vectors.
 | 
			
		||||
	 */
 | 
			
		||||
 | 
			
		||||
	local_key_vector = sctp_auth_make_local_vector(asoc, gfp);
 | 
			
		||||
	peer_key_vector = sctp_auth_make_peer_vector(asoc, gfp);
 | 
			
		||||
 | 
			
		||||
	if (!peer_key_vector || !local_key_vector)
 | 
			
		||||
		goto out;
 | 
			
		||||
 | 
			
		||||
	/* Figure out the order in wich the key_vectors will be
 | 
			
		||||
	 * added to the endpoint shared key.
 | 
			
		||||
	 * SCTP-AUTH, Section 6.1:
 | 
			
		||||
	 *   This is performed by selecting the numerically smaller key
 | 
			
		||||
	 *   vector and concatenating it to the endpoint pair shared
 | 
			
		||||
	 *   key, and then concatenating the numerically larger key
 | 
			
		||||
	 *   vector to that.  If the key vectors are equal as numbers
 | 
			
		||||
	 *   but differ in length, then the concatenation order is the
 | 
			
		||||
	 *   endpoint shared key, followed by the shorter key vector,
 | 
			
		||||
	 *   followed by the longer key vector.  Otherwise, the key
 | 
			
		||||
	 *   vectors are identical, and may be concatenated to the
 | 
			
		||||
	 *   endpoint pair key in any order.
 | 
			
		||||
	 */
 | 
			
		||||
	cmp = sctp_auth_compare_vectors(local_key_vector,
 | 
			
		||||
					peer_key_vector);
 | 
			
		||||
	if (cmp < 0) {
 | 
			
		||||
		first_vector = local_key_vector;
 | 
			
		||||
		last_vector = peer_key_vector;
 | 
			
		||||
	} else {
 | 
			
		||||
		first_vector = peer_key_vector;
 | 
			
		||||
		last_vector = local_key_vector;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	secret = sctp_auth_asoc_set_secret(ep_key, first_vector, last_vector,
 | 
			
		||||
					    gfp);
 | 
			
		||||
out:
 | 
			
		||||
	kfree(local_key_vector);
 | 
			
		||||
	kfree(peer_key_vector);
 | 
			
		||||
 | 
			
		||||
	return secret;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Populate the association overlay list with the list
 | 
			
		||||
 * from the endpoint.
 | 
			
		||||
 */
 | 
			
		||||
int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
 | 
			
		||||
				struct sctp_association *asoc,
 | 
			
		||||
				gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_shared_key *sh_key;
 | 
			
		||||
	struct sctp_shared_key *new;
 | 
			
		||||
 | 
			
		||||
	BUG_ON(!list_empty(&asoc->endpoint_shared_keys));
 | 
			
		||||
 | 
			
		||||
	key_for_each(sh_key, &ep->endpoint_shared_keys) {
 | 
			
		||||
		new = sctp_auth_shkey_create(sh_key->key_id, gfp);
 | 
			
		||||
		if (!new)
 | 
			
		||||
			goto nomem;
 | 
			
		||||
 | 
			
		||||
		new->key = sh_key->key;
 | 
			
		||||
		sctp_auth_key_hold(new->key);
 | 
			
		||||
		list_add(&new->key_list, &asoc->endpoint_shared_keys);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
 | 
			
		||||
nomem:
 | 
			
		||||
	sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
 | 
			
		||||
	return -ENOMEM;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
/* Public interface to creat the association shared key.
 | 
			
		||||
 * See code above for the algorithm.
 | 
			
		||||
 */
 | 
			
		||||
int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_auth_bytes	*secret;
 | 
			
		||||
	struct sctp_shared_key *ep_key;
 | 
			
		||||
 | 
			
		||||
	/* If we don't support AUTH, or peer is not capable
 | 
			
		||||
	 * we don't need to do anything.
 | 
			
		||||
	 */
 | 
			
		||||
	if (!sctp_auth_enable || !asoc->peer.auth_capable)
 | 
			
		||||
		return 0;
 | 
			
		||||
 | 
			
		||||
	/* If the key_id is non-zero and we couldn't find an
 | 
			
		||||
	 * endpoint pair shared key, we can't compute the
 | 
			
		||||
	 * secret.
 | 
			
		||||
	 * For key_id 0, endpoint pair shared key is a NULL key.
 | 
			
		||||
	 */
 | 
			
		||||
	ep_key = sctp_auth_get_shkey(asoc, asoc->active_key_id);
 | 
			
		||||
	BUG_ON(!ep_key);
 | 
			
		||||
 | 
			
		||||
	secret = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
 | 
			
		||||
	if (!secret)
 | 
			
		||||
		return -ENOMEM;
 | 
			
		||||
 | 
			
		||||
	sctp_auth_key_put(asoc->asoc_shared_key);
 | 
			
		||||
	asoc->asoc_shared_key = secret;
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
/* Find the endpoint pair shared key based on the key_id */
 | 
			
		||||
struct sctp_shared_key *sctp_auth_get_shkey(
 | 
			
		||||
				const struct sctp_association *asoc,
 | 
			
		||||
				__u16 key_id)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_shared_key *key = NULL;
 | 
			
		||||
 | 
			
		||||
	/* First search associations set of endpoint pair shared keys */
 | 
			
		||||
	key_for_each(key, &asoc->endpoint_shared_keys) {
 | 
			
		||||
		if (key->key_id == key_id)
 | 
			
		||||
			break;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return key;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Initialize all the possible digest transforms that we can use.  Right now
 | 
			
		||||
 * now, the supported digests are SHA1 and SHA256.  We do this here once
 | 
			
		||||
 * because of the restrictiong that transforms may only be allocated in
 | 
			
		||||
 * user context.  This forces us to pre-allocated all possible transforms
 | 
			
		||||
 * at the endpoint init time.
 | 
			
		||||
 */
 | 
			
		||||
int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct crypto_hash *tfm = NULL;
 | 
			
		||||
	__u16   id;
 | 
			
		||||
 | 
			
		||||
	/* if the transforms are already allocted, we are done */
 | 
			
		||||
	if (!sctp_auth_enable) {
 | 
			
		||||
		ep->auth_hmacs = NULL;
 | 
			
		||||
		return 0;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (ep->auth_hmacs)
 | 
			
		||||
		return 0;
 | 
			
		||||
 | 
			
		||||
	/* Allocated the array of pointers to transorms */
 | 
			
		||||
	ep->auth_hmacs = kzalloc(
 | 
			
		||||
			    sizeof(struct crypto_hash *) * SCTP_AUTH_NUM_HMACS,
 | 
			
		||||
			    gfp);
 | 
			
		||||
	if (!ep->auth_hmacs)
 | 
			
		||||
		return -ENOMEM;
 | 
			
		||||
 | 
			
		||||
	for (id = 0; id < SCTP_AUTH_NUM_HMACS; id++) {
 | 
			
		||||
 | 
			
		||||
		/* See is we support the id.  Supported IDs have name and
 | 
			
		||||
		 * length fields set, so that we can allocated and use
 | 
			
		||||
		 * them.  We can safely just check for name, for without the
 | 
			
		||||
		 * name, we can't allocate the TFM.
 | 
			
		||||
		 */
 | 
			
		||||
		if (!sctp_hmac_list[id].hmac_name)
 | 
			
		||||
			continue;
 | 
			
		||||
 | 
			
		||||
		/* If this TFM has been allocated, we are all set */
 | 
			
		||||
		if (ep->auth_hmacs[id])
 | 
			
		||||
			continue;
 | 
			
		||||
 | 
			
		||||
		/* Allocate the ID */
 | 
			
		||||
		tfm = crypto_alloc_hash(sctp_hmac_list[id].hmac_name, 0,
 | 
			
		||||
					CRYPTO_ALG_ASYNC);
 | 
			
		||||
		if (IS_ERR(tfm))
 | 
			
		||||
			goto out_err;
 | 
			
		||||
 | 
			
		||||
		ep->auth_hmacs[id] = tfm;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
 | 
			
		||||
out_err:
 | 
			
		||||
	/* Clean up any successfull allocations */
 | 
			
		||||
	sctp_auth_destroy_hmacs(ep->auth_hmacs);
 | 
			
		||||
	return -ENOMEM;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Destroy the hmac tfm array */
 | 
			
		||||
void sctp_auth_destroy_hmacs(struct crypto_hash *auth_hmacs[])
 | 
			
		||||
{
 | 
			
		||||
	int i;
 | 
			
		||||
 | 
			
		||||
	if (!auth_hmacs)
 | 
			
		||||
		return;
 | 
			
		||||
 | 
			
		||||
	for (i = 0; i < SCTP_AUTH_NUM_HMACS; i++)
 | 
			
		||||
	{
 | 
			
		||||
		if (auth_hmacs[i])
 | 
			
		||||
			crypto_free_hash(auth_hmacs[i]);
 | 
			
		||||
	}
 | 
			
		||||
	kfree(auth_hmacs);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id)
 | 
			
		||||
{
 | 
			
		||||
	return &sctp_hmac_list[hmac_id];
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Get an hmac description information that we can use to build
 | 
			
		||||
 * the AUTH chunk
 | 
			
		||||
 */
 | 
			
		||||
struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_hmac_algo_param *hmacs;
 | 
			
		||||
	__u16 n_elt;
 | 
			
		||||
	__u16 id = 0;
 | 
			
		||||
	int i;
 | 
			
		||||
 | 
			
		||||
	/* If we have a default entry, use it */
 | 
			
		||||
	if (asoc->default_hmac_id)
 | 
			
		||||
		return &sctp_hmac_list[asoc->default_hmac_id];
 | 
			
		||||
 | 
			
		||||
	/* Since we do not have a default entry, find the first entry
 | 
			
		||||
	 * we support and return that.  Do not cache that id.
 | 
			
		||||
	 */
 | 
			
		||||
	hmacs = asoc->peer.peer_hmacs;
 | 
			
		||||
	if (!hmacs)
 | 
			
		||||
		return NULL;
 | 
			
		||||
 | 
			
		||||
	n_elt = (ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t)) >> 1;
 | 
			
		||||
	for (i = 0; i < n_elt; i++) {
 | 
			
		||||
		id = ntohs(hmacs->hmac_ids[i]);
 | 
			
		||||
 | 
			
		||||
		/* Check the id is in the supported range */
 | 
			
		||||
		if (id > SCTP_AUTH_HMAC_ID_MAX)
 | 
			
		||||
			continue;
 | 
			
		||||
 | 
			
		||||
		/* See is we support the id.  Supported IDs have name and
 | 
			
		||||
		 * length fields set, so that we can allocated and use
 | 
			
		||||
		 * them.  We can safely just check for name, for without the
 | 
			
		||||
		 * name, we can't allocate the TFM.
 | 
			
		||||
		 */
 | 
			
		||||
		if (!sctp_hmac_list[id].hmac_name)
 | 
			
		||||
			continue;
 | 
			
		||||
 | 
			
		||||
		break;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (id == 0)
 | 
			
		||||
		return NULL;
 | 
			
		||||
 | 
			
		||||
	return &sctp_hmac_list[id];
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int __sctp_auth_find_hmacid(__u16 *hmacs, int n_elts, __u16 hmac_id)
 | 
			
		||||
{
 | 
			
		||||
	int  found = 0;
 | 
			
		||||
	int  i;
 | 
			
		||||
 | 
			
		||||
	for (i = 0; i < n_elts; i++) {
 | 
			
		||||
		if (hmac_id == hmacs[i]) {
 | 
			
		||||
			found = 1;
 | 
			
		||||
			break;
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return found;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* See if the HMAC_ID is one that we claim as supported */
 | 
			
		||||
int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
 | 
			
		||||
				    __u16 hmac_id)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_hmac_algo_param *hmacs;
 | 
			
		||||
	__u16 n_elt;
 | 
			
		||||
 | 
			
		||||
	if (!asoc)
 | 
			
		||||
		return 0;
 | 
			
		||||
 | 
			
		||||
	hmacs = (struct sctp_hmac_algo_param *)asoc->c.auth_hmacs;
 | 
			
		||||
	n_elt = (ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t)) >> 1;
 | 
			
		||||
 | 
			
		||||
	return __sctp_auth_find_hmacid(hmacs->hmac_ids, n_elt, hmac_id);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
/* Cache the default HMAC id.  This to follow this text from SCTP-AUTH:
 | 
			
		||||
 * Section 6.1:
 | 
			
		||||
 *   The receiver of a HMAC-ALGO parameter SHOULD use the first listed
 | 
			
		||||
 *   algorithm it supports.
 | 
			
		||||
 */
 | 
			
		||||
void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
 | 
			
		||||
				     struct sctp_hmac_algo_param *hmacs)
 | 
			
		||||
{
 | 
			
		||||
	struct sctp_endpoint *ep;
 | 
			
		||||
	__u16   id;
 | 
			
		||||
	int	i;
 | 
			
		||||
	int	n_params;
 | 
			
		||||
 | 
			
		||||
	/* if the default id is already set, use it */
 | 
			
		||||
	if (asoc->default_hmac_id)
 | 
			
		||||
		return;
 | 
			
		||||
 | 
			
		||||
	n_params = (ntohs(hmacs->param_hdr.length)
 | 
			
		||||
				- sizeof(sctp_paramhdr_t)) >> 1;
 | 
			
		||||
	ep = asoc->ep;
 | 
			
		||||
	for (i = 0; i < n_params; i++) {
 | 
			
		||||
		id = ntohs(hmacs->hmac_ids[i]);
 | 
			
		||||
 | 
			
		||||
		/* Check the id is in the supported range */
 | 
			
		||||
		if (id > SCTP_AUTH_HMAC_ID_MAX)
 | 
			
		||||
			continue;
 | 
			
		||||
 | 
			
		||||
		/* If this TFM has been allocated, use this id */
 | 
			
		||||
		if (ep->auth_hmacs[id]) {
 | 
			
		||||
			asoc->default_hmac_id = id;
 | 
			
		||||
			break;
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
/* Check to see if the given chunk is supposed to be authenticated */
 | 
			
		||||
static int __sctp_auth_cid(sctp_cid_t chunk, struct sctp_chunks_param *param)
 | 
			
		||||
{
 | 
			
		||||
	unsigned short len;
 | 
			
		||||
	int found = 0;
 | 
			
		||||
	int i;
 | 
			
		||||
 | 
			
		||||
	if (!param)
 | 
			
		||||
		return 0;
 | 
			
		||||
 | 
			
		||||
	len = ntohs(param->param_hdr.length) - sizeof(sctp_paramhdr_t);
 | 
			
		||||
 | 
			
		||||
	/* SCTP-AUTH, Section 3.2
 | 
			
		||||
	 *    The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH
 | 
			
		||||
	 *    chunks MUST NOT be listed in the CHUNKS parameter.  However, if
 | 
			
		||||
	 *    a CHUNKS parameter is received then the types for INIT, INIT-ACK,
 | 
			
		||||
	 *    SHUTDOWN-COMPLETE and AUTH chunks MUST be ignored.
 | 
			
		||||
	 */
 | 
			
		||||
	for (i = 0; !found && i < len; i++) {
 | 
			
		||||
		switch (param->chunks[i]) {
 | 
			
		||||
		    case SCTP_CID_INIT:
 | 
			
		||||
		    case SCTP_CID_INIT_ACK:
 | 
			
		||||
		    case SCTP_CID_SHUTDOWN_COMPLETE:
 | 
			
		||||
		    case SCTP_CID_AUTH:
 | 
			
		||||
			break;
 | 
			
		||||
 | 
			
		||||
		    default:
 | 
			
		||||
			if (param->chunks[i] == chunk)
 | 
			
		||||
			    found = 1;
 | 
			
		||||
			break;
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	return found;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Check if peer requested that this chunk is authenticated */
 | 
			
		||||
int sctp_auth_send_cid(sctp_cid_t chunk, const struct sctp_association *asoc)
 | 
			
		||||
{
 | 
			
		||||
	if (!sctp_auth_enable || !asoc || !asoc->peer.auth_capable)
 | 
			
		||||
		return 0;
 | 
			
		||||
 | 
			
		||||
	return __sctp_auth_cid(chunk, asoc->peer.peer_chunks);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* Check if we requested that peer authenticate this chunk. */
 | 
			
		||||
int sctp_auth_recv_cid(sctp_cid_t chunk, const struct sctp_association *asoc)
 | 
			
		||||
{
 | 
			
		||||
	if (!sctp_auth_enable || !asoc)
 | 
			
		||||
		return 0;
 | 
			
		||||
 | 
			
		||||
	return __sctp_auth_cid(chunk,
 | 
			
		||||
			      (struct sctp_chunks_param *)asoc->c.auth_chunks);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/* SCTP-AUTH: Section 6.2:
 | 
			
		||||
 *    The sender MUST calculate the MAC as described in RFC2104 [2] using
 | 
			
		||||
 *    the hash function H as described by the MAC Identifier and the shared
 | 
			
		||||
 *    association key K based on the endpoint pair shared key described by
 | 
			
		||||
 *    the shared key identifier.  The 'data' used for the computation of
 | 
			
		||||
 *    the AUTH-chunk is given by the AUTH chunk with its HMAC field set to
 | 
			
		||||
 *    zero (as shown in Figure 6) followed by all chunks that are placed
 | 
			
		||||
 *    after the AUTH chunk in the SCTP packet.
 | 
			
		||||
 */
 | 
			
		||||
void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
 | 
			
		||||
			      struct sk_buff *skb,
 | 
			
		||||
			      struct sctp_auth_chunk *auth,
 | 
			
		||||
			      gfp_t gfp)
 | 
			
		||||
{
 | 
			
		||||
	struct scatterlist sg;
 | 
			
		||||
	struct hash_desc desc;
 | 
			
		||||
	struct sctp_auth_bytes *asoc_key;
 | 
			
		||||
	__u16 key_id, hmac_id;
 | 
			
		||||
	__u8 *digest;
 | 
			
		||||
	unsigned char *end;
 | 
			
		||||
	int free_key = 0;
 | 
			
		||||
 | 
			
		||||
	/* Extract the info we need:
 | 
			
		||||
	 * - hmac id
 | 
			
		||||
	 * - key id
 | 
			
		||||
	 */
 | 
			
		||||
	key_id = ntohs(auth->auth_hdr.shkey_id);
 | 
			
		||||
	hmac_id = ntohs(auth->auth_hdr.hmac_id);
 | 
			
		||||
 | 
			
		||||
	if (key_id == asoc->active_key_id)
 | 
			
		||||
		asoc_key = asoc->asoc_shared_key;
 | 
			
		||||
	else {
 | 
			
		||||
		struct sctp_shared_key *ep_key;
 | 
			
		||||
 | 
			
		||||
		ep_key = sctp_auth_get_shkey(asoc, key_id);
 | 
			
		||||
		if (!ep_key)
 | 
			
		||||
			return;
 | 
			
		||||
 | 
			
		||||
		asoc_key = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
 | 
			
		||||
		if (!asoc_key)
 | 
			
		||||
			return;
 | 
			
		||||
 | 
			
		||||
		free_key = 1;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	/* set up scatter list */
 | 
			
		||||
	end = skb_tail_pointer(skb);
 | 
			
		||||
	sg.page = virt_to_page(auth);
 | 
			
		||||
	sg.offset = (unsigned long)(auth) % PAGE_SIZE;
 | 
			
		||||
	sg.length = end - (unsigned char *)auth;
 | 
			
		||||
 | 
			
		||||
	desc.tfm = asoc->ep->auth_hmacs[hmac_id];
 | 
			
		||||
	desc.flags = 0;
 | 
			
		||||
 | 
			
		||||
	digest = auth->auth_hdr.hmac;
 | 
			
		||||
	if (crypto_hash_setkey(desc.tfm, &asoc_key->data[0], asoc_key->len))
 | 
			
		||||
		goto free;
 | 
			
		||||
 | 
			
		||||
	crypto_hash_digest(&desc, &sg, sg.length, digest);
 | 
			
		||||
 | 
			
		||||
free:
 | 
			
		||||
	if (free_key)
 | 
			
		||||
		sctp_auth_key_put(asoc_key);
 | 
			
		||||
}
 | 
			
		||||
| 
						 | 
				
			
			@ -58,6 +58,7 @@ SCTP_DBG_OBJCNT(chunk);
 | 
			
		|||
SCTP_DBG_OBJCNT(addr);
 | 
			
		||||
SCTP_DBG_OBJCNT(ssnmap);
 | 
			
		||||
SCTP_DBG_OBJCNT(datamsg);
 | 
			
		||||
SCTP_DBG_OBJCNT(keys);
 | 
			
		||||
 | 
			
		||||
/* An array to make it easy to pretty print the debug information
 | 
			
		||||
 * to the proc fs.
 | 
			
		||||
| 
						 | 
				
			
			@ -73,6 +74,7 @@ static sctp_dbg_objcnt_entry_t sctp_dbg_objcnt[] = {
 | 
			
		|||
	SCTP_DBG_OBJCNT_ENTRY(addr),
 | 
			
		||||
	SCTP_DBG_OBJCNT_ENTRY(ssnmap),
 | 
			
		||||
	SCTP_DBG_OBJCNT_ENTRY(datamsg),
 | 
			
		||||
	SCTP_DBG_OBJCNT_ENTRY(keys),
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
/* Callback from procfs to read out objcount information.
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
		Loading…
	
		Reference in a new issue