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Date: Fri, 14 Sep 2007 14:44:53 -0400
From: Vlad Yasevich <vladislav.yasevich@...com>
To: lksctp-developers@...ts.sourceforge.net
Cc: netdev@...r.kernel.org, Vlad Yasevich <vladislav.yasevich@...com>
Subject: [PATCH 2/8] 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@...com>
---
include/net/sctp/auth.h | 112 +++++++
include/net/sctp/constants.h | 49 +++-
include/net/sctp/sctp.h | 1 +
include/net/sctp/structs.h | 71 ++++-
net/sctp/Makefile | 3 +-
net/sctp/auth.c | 744 ++++++++++++++++++++++++++++++++++++++++++
net/sctp/objcnt.c | 2 +
7 files changed, 975 insertions(+), 7 deletions(-)
create mode 100644 include/net/sctp/auth.h
create mode 100644 net/sctp/auth.c
diff --git a/include/net/sctp/auth.h b/include/net/sctp/auth.h
new file mode 100644
index 0000000..10c8010
--- /dev/null
+++ b/include/net/sctp/auth.h
@@ -0,0 +1,112 @@
+/* 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@...ts.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@...com>
+ *
+ * Any bugs reported given to us we will try to fix... any fixes shared will
+ * be incorporated into the next SCTP release.
+ */
+
+#ifndef __sctp_auth_h__
+#define __sctp_auth_h__
+
+#include <linux/list.h>
+#include <linux/crypto.h>
+
+struct sctp_endpoint;
+struct sctp_association;
+struct sctp_authkey;
+
+/*
+ * Define a generic struct that will hold all the info
+ * necessary for an HMAC transform
+ */
+struct sctp_hmac {
+ __u16 hmac_id; /* one of the above ids */
+ char *hmac_name; /* name for loading */
+ __u16 hmac_len; /* length of the signature */
+};
+
+/* This is generic structure that containst authentication bytes used
+ * as keying material. It's a what is referred to as byte-vector all
+ * over SCTP-AUTH
+ */
+struct sctp_auth_bytes {
+ atomic_t refcnt;
+ __u32 len;
+ __u8 data[];
+};
+
+/* Definition for a shared key, weather endpoint or association */
+struct sctp_shared_key {
+ struct list_head key_list;
+ __u16 key_id;
+ struct sctp_auth_bytes *key;
+};
+
+#define key_for_each(__key, __list_head) \
+ list_for_each_entry(__key, __list_head, key_list)
+
+#define key_for_each_safe(__key, __tmp, __list_head) \
+ list_for_each_entry_safe(__key, __tmp, __list_head, key_list)
+
+static inline void sctp_auth_key_hold(struct sctp_auth_bytes *key)
+{
+ if (!key)
+ return;
+
+ atomic_inc(&key->refcnt);
+}
+
+void sctp_auth_key_put(struct sctp_auth_bytes *key);
+struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp);
+void sctp_auth_shkey_free(struct sctp_shared_key *sh_key);
+void sctp_auth_destroy_keys(struct list_head *keys);
+int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp);
+struct sctp_shared_key *sctp_auth_get_shkey(
+ const struct sctp_association *asoc,
+ __u16 key_id);
+int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
+ struct sctp_association *asoc,
+ gfp_t gfp);
+int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp);
+void sctp_auth_destroy_hmacs(struct crypto_hash *auth_hmacs[]);
+struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id);
+struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc);
+void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
+ struct sctp_hmac_algo_param *hmacs);
+int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
+ __u16 hmac_id);
+int sctp_auth_send_cid(sctp_cid_t chunk, const struct sctp_association *asoc);
+int sctp_auth_recv_cid(sctp_cid_t chunk, const struct sctp_association *asoc);
+void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
+ struct sk_buff *skb,
+ struct sctp_auth_chunk *auth, gfp_t gfp);
+#endif
diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index bb37724..777118f 100644
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -64,12 +64,18 @@ enum { SCTP_DEFAULT_INSTREAMS = SCTP_MAX_STREAM };
#define SCTP_CID_MAX SCTP_CID_ASCONF_ACK
#define SCTP_NUM_BASE_CHUNK_TYPES (SCTP_CID_BASE_MAX + 1)
-#define SCTP_NUM_CHUNK_TYPES (SCTP_NUM_BASE_CHUNKTYPES + 2)
#define SCTP_NUM_ADDIP_CHUNK_TYPES 2
#define SCTP_NUM_PRSCTP_CHUNK_TYPES 1
+#define SCTP_NUM_AUTH_CHUNK_TYPES 1
+
+#define SCTP_NUM_CHUNK_TYPES (SCTP_NUM_BASE_CHUNK_TYPES + \
+ SCTP_NUM_ADDIP_CHUNK_TYPES +\
+ SCTP_NUM_PRSCTP_CHUNK_TYPES +\
+ SCTP_NUM_AUTH_CHUNK_TYPES)
+
/* These are the different flavours of event. */
typedef enum {
@@ -409,4 +415,45 @@ typedef enum {
SCTP_LOWER_CWND_INACTIVE,
} sctp_lower_cwnd_t;
+
+/* SCTP-AUTH Necessary constants */
+
+/* SCTP-AUTH, Section 3.3
+ *
+ * The following Table 2 shows the currently defined values for HMAC
+ * identifiers.
+ *
+ * +-----------------+--------------------------+
+ * | HMAC Identifier | Message Digest Algorithm |
+ * +-----------------+--------------------------+
+ * | 0 | Reserved |
+ * | 1 | SHA-1 defined in [8] |
+ * | 2 | Reserved |
+ * | 3 | SHA-256 defined in [8] |
+ * +-----------------+--------------------------+
+ */
+enum {
+ SCTP_AUTH_HMAC_ID_RESERVED_0,
+ SCTP_AUTH_HMAC_ID_SHA1,
+ SCTP_AUTH_HMAC_ID_RESERVED_2,
+ SCTP_AUTH_HMAC_ID_SHA256
+};
+
+#define SCTP_AUTH_HMAC_ID_MAX SCTP_AUTH_HMAC_ID_SHA256
+#define SCTP_AUTH_NUM_HMACS (SCTP_AUTH_HMAC_ID_SHA256 + 1)
+#define SCTP_SHA1_SIG_SIZE 20
+#define SCTP_SHA256_SIG_SIZE 32
+
+/* 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
+ */
+#define SCTP_NUM_NOAUTH_CHUNKS 4
+#define SCTP_AUTH_MAX_CHUNKS (SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS)
+
+/* SCTP-AUTH Section 6.1
+ * The RANDOM parameter MUST contain a 32 byte random number.
+ */
+#define SCTP_AUTH_RANDOM_LENGTH 32
+
#endif /* __sctp_constants_h__ */
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 46d7d09..b542e96 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -340,6 +340,7 @@ extern atomic_t sctp_dbg_objcnt_bind_bucket;
extern atomic_t sctp_dbg_objcnt_addr;
extern atomic_t sctp_dbg_objcnt_ssnmap;
extern atomic_t sctp_dbg_objcnt_datamsg;
+extern atomic_t sctp_dbg_objcnt_keys;
/* Macros to atomically increment/decrement objcnt counters. */
#define SCTP_DBG_OBJCNT_INC(name) \
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 8505ecc..a668825 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -64,6 +64,7 @@
#include <linux/skbuff.h> /* We need sk_buff_head. */
#include <linux/workqueue.h> /* We need tq_struct. */
#include <linux/sctp.h> /* We need sctp* header structs. */
+#include <net/sctp/auth.h> /* We need auth specific structs */
/* A convenience structure for handling sockaddr structures.
* We should wean ourselves off this.
@@ -213,6 +214,9 @@ extern struct sctp_globals {
/* Flag to indicate if PR-SCTP is enabled. */
int prsctp_enable;
+
+ /* Flag to idicate if SCTP-AUTH is enabled */
+ int auth_enable;
} sctp_globals;
#define sctp_rto_initial (sctp_globals.rto_initial)
@@ -244,6 +248,7 @@ extern struct sctp_globals {
#define sctp_local_addr_list (sctp_globals.local_addr_list)
#define sctp_addip_enable (sctp_globals.addip_enable)
#define sctp_prsctp_enable (sctp_globals.prsctp_enable)
+#define sctp_auth_enable (sctp_globals.auth_enable)
/* SCTP Socket type: UDP or TCP style. */
typedef enum {
@@ -393,6 +398,9 @@ struct sctp_cookie {
__u32 adaptation_ind;
+ __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
+ __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS + 2];
+ __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
/* This is a shim for my peer's INIT packet, followed by
* a copy of the raw address list of the association.
@@ -436,6 +444,9 @@ union sctp_params {
union sctp_addr_param *addr;
struct sctp_adaptation_ind_param *aind;
struct sctp_supported_ext_param *ext;
+ struct sctp_random_param *random;
+ struct sctp_chunks_param *chunks;
+ struct sctp_hmac_algo_param *hmac_algo;
};
/* RFC 2960. Section 3.3.5 Heartbeat.
@@ -674,6 +685,7 @@ struct sctp_chunk {
struct sctp_errhdr *err_hdr;
struct sctp_addiphdr *addip_hdr;
struct sctp_fwdtsn_hdr *fwdtsn_hdr;
+ struct sctp_authhdr *auth_hdr;
} subh;
__u8 *chunk_end;
@@ -719,6 +731,7 @@ struct sctp_chunk {
__s8 fast_retransmit; /* Is this chunk fast retransmitted? */
__u8 tsn_missing_report; /* Data chunk missing counter. */
__u8 data_accepted; /* At least 1 chunk in this packet accepted */
+ __u8 auth; /* IN: was auth'ed | OUT: needs auth */
};
void sctp_chunk_hold(struct sctp_chunk *);
@@ -766,16 +779,22 @@ struct sctp_packet {
*/
struct sctp_transport *transport;
+ /* pointer to the auth chunk for this packet */
+ struct sctp_chunk *auth;
+
/* This packet contains a COOKIE-ECHO chunk. */
- char has_cookie_echo;
+ __u8 has_cookie_echo;
+
+ /* This packet contains a SACK chunk. */
+ __u8 has_sack;
- /* This packet containsa SACK chunk. */
- char has_sack;
+ /* This packet contains an AUTH chunk */
+ __u8 has_auth;
/* SCTP cannot fragment this packet. So let ip fragment it. */
- char ipfragok;
+ __u8 ipfragok;
- int malloced;
+ __u8 malloced;
};
struct sctp_packet *sctp_packet_init(struct sctp_packet *,
@@ -1285,6 +1304,21 @@ struct sctp_endpoint {
/* rcvbuf acct. policy. */
__u32 rcvbuf_policy;
+
+ /* SCTP AUTH: array of the HMACs that will be allocated
+ * we need this per association so that we don't serialize
+ */
+ struct crypto_hash **auth_hmacs;
+
+ /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
+ struct sctp_hmac_algo_param *auth_hmacs_list;
+
+ /* SCTP-AUTH: chunks to authenticate encoded into parameter */
+ struct sctp_chunks_param *auth_chunk_list;
+
+ /* SCTP-AUTH: endpoint shared keys */
+ struct list_head endpoint_shared_keys;
+ __u16 active_key_id;
};
/* Recover the outter endpoint structure. */
@@ -1491,6 +1525,7 @@ struct sctp_association {
__u8 hostname_address;/* Peer understands DNS addresses? */
__u8 asconf_capable; /* Does peer support ADDIP? */
__u8 prsctp_capable; /* Can peer do PR-SCTP? */
+ __u8 auth_capable; /* Is peer doing SCTP-AUTH? */
__u32 adaptation_ind; /* Adaptation Code point. */
@@ -1508,6 +1543,14 @@ struct sctp_association {
* Initial TSN Value minus 1
*/
__u32 addip_serial;
+
+ /* SCTP-AUTH: We need to know pears random number, hmac list
+ * and authenticated chunk list. All that is part of the
+ * cookie and these are just pointers to those locations
+ */
+ 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
@@ -1791,6 +1834,24 @@ 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;
diff --git a/net/sctp/Makefile b/net/sctp/Makefile
index 70c828b..1da7204 100644
--- a/net/sctp/Makefile
+++ b/net/sctp/Makefile
@@ -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
diff --git a/net/sctp/auth.c b/net/sctp/auth.c
new file mode 100644
index 0000000..1fee43e
--- /dev/null
+++ b/net/sctp/auth.c
@@ -0,0 +1,744 @@
+/* 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@...ts.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@...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 <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);
+}
diff --git a/net/sctp/objcnt.c b/net/sctp/objcnt.c
index fcfb9d8..2cf6ad6 100644
--- a/net/sctp/objcnt.c
+++ b/net/sctp/objcnt.c
@@ -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.
--
1.5.2.4
-
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