[SCTP]: Implement SCTP-AUTH initializations.

The patch initializes AUTH related members of the generic SCTP
structures and provides a way to enable/disable auth extension.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 133 insertions, 0 deletions

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 9bad8ba0feda..ee4b212e66b1 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -74,6 +74,8 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 {
         struct sctp_sock *sp;
         int i;
+        sctp_paramhdr_t *p;
+        int err;
 
         /* Retrieve the SCTP per socket area.  */
         sp = sctp_sk((struct sock *)sk);
@@ -298,6 +300,30 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
         asoc->default_timetolive = sp->default_timetolive;
         asoc->default_rcv_context = sp->default_rcv_context;
 
+        /* AUTH related initializations */
+        INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
+        err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp);
+        if (err)
+                goto fail_init;
+
+        asoc->active_key_id = ep->active_key_id;
+        asoc->asoc_shared_key = NULL;
+
+        asoc->default_hmac_id = 0;
+        /* Save the hmacs and chunks list into this association */
+        if (ep->auth_hmacs_list)
+                memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
+                        ntohs(ep->auth_hmacs_list->param_hdr.length));
+        if (ep->auth_chunk_list)
+                memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
+                        ntohs(ep->auth_chunk_list->param_hdr.length));
+
+        /* Get the AUTH random number for this association */
+        p = (sctp_paramhdr_t *)asoc->c.auth_random;
+        p->type = SCTP_PARAM_RANDOM;
+        p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
+        get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
+
         return asoc;
 
 fail_init:
@@ -407,6 +433,12 @@ void sctp_association_free(struct sctp_association *asoc)
         if (asoc->addip_last_asconf)
                 sctp_chunk_free(asoc->addip_last_asconf);
 
+        /* AUTH - Free the endpoint shared keys */
+        sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
+
+        /* AUTH - Free the association shared key */
+        sctp_auth_key_put(asoc->asoc_shared_key);
+
         sctp_association_put(asoc);
 }
 
@@ -1112,6 +1144,8 @@ void sctp_assoc_update(struct sctp_association *asoc,
                         sctp_assoc_set_id(asoc, GFP_ATOMIC);
                 }
         }
+
+        /* SCTP-AUTH: XXX something needs to be done here*/
 }
 
 /* Update the retran path for sending a retransmitted packet.
diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index 22371185efb6..c8d5023606a5 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -69,12 +69,56 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
                                                 struct sock *sk,
                                                 gfp_t gfp)
 {
+        struct sctp_hmac_algo_param *auth_hmacs = NULL;
+        struct sctp_chunks_param *auth_chunks = NULL;
+        struct sctp_shared_key *null_key;
+        int err;
+
         memset(ep, 0, sizeof(struct sctp_endpoint));
 
         ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
         if (!ep->digest)
                 return NULL;
 
+        if (sctp_auth_enable) {
+                /* Allocate space for HMACS and CHUNKS authentication
+                 * variables.  There are arrays that we encode directly
+                 * into parameters to make the rest of the operations easier.
+                 */
+                auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
+                                sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
+                if (!auth_hmacs)
+                        goto nomem;
+
+                auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
+                                        SCTP_NUM_CHUNK_TYPES, gfp);
+                if (!auth_chunks)
+                        goto nomem;
+
+                /* Initialize the HMACS parameter.
+                 * SCTP-AUTH: Section 3.3
+                 *    Every endpoint supporting SCTP chunk authentication MUST
+                 *    support the HMAC based on the SHA-1 algorithm.
+                 */
+                auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
+                auth_hmacs->param_hdr.length =
+                                        htons(sizeof(sctp_paramhdr_t) + 2);
+                auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
+
+                /* Initialize the CHUNKS parameter */
+                auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
+
+                /* If the Add-IP functionality is enabled, we must
+                 * authenticate, ASCONF and ASCONF-ACK chunks
+                 */
+                if (sctp_addip_enable) {
+                        auth_chunks->chunks[0] = SCTP_CID_ASCONF;
+                        auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK;
+                        auth_chunks->param_hdr.length =
+                                        htons(sizeof(sctp_paramhdr_t) + 2);
+                }
+        }
+
         /* Initialize the base structure. */
         /* What type of endpoint are we?  */
         ep->base.type = SCTP_EP_TYPE_SOCKET;
@@ -114,7 +158,36 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
         ep->last_key = ep->current_key = 0;
         ep->key_changed_at = jiffies;
 
+        /* SCTP-AUTH extensions*/
+        INIT_LIST_HEAD(&ep->endpoint_shared_keys);
+        null_key = sctp_auth_shkey_create(0, GFP_KERNEL);
+        if (!null_key)
+                goto nomem;
+
+        list_add(&null_key->key_list, &ep->endpoint_shared_keys);
+
+        /* Allocate and initialize transorms arrays for suported HMACs. */
+        err = sctp_auth_init_hmacs(ep, gfp);
+        if (err)
+                goto nomem_hmacs;
+
+        /* Add the null key to the endpoint shared keys list and
+         * set the hmcas and chunks pointers.
+         */
+        ep->auth_hmacs_list = auth_hmacs;
+        ep->auth_chunk_list = auth_chunks;
+
         return ep;
+
+nomem_hmacs:
+        sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
+nomem:
+        /* Free all allocations */
+        kfree(auth_hmacs);
+        kfree(auth_chunks);
+        kfree(ep->digest);
+        return NULL;
+
 }
 
 /* Create a sctp_endpoint with all that boring stuff initialized.
@@ -187,6 +260,16 @@ static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
         /* Free the digest buffer */
         kfree(ep->digest);
 
+        /* SCTP-AUTH: Free up AUTH releated data such as shared keys
+         * chunks and hmacs arrays that were allocated
+         */
+        sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
+        kfree(ep->auth_hmacs_list);
+        kfree(ep->auth_chunk_list);
+
+        /* AUTH - Free any allocated HMAC transform containers */
+        sctp_auth_destroy_hmacs(ep->auth_hmacs);
+
         /* Cleanup. */
         sctp_inq_free(&ep->base.inqueue);
         sctp_bind_addr_free(&ep->base.bind_addr);
diff --git a/net/sctp/output.c b/net/sctp/output.c
index d85543def754..49b9f5f031a4 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -79,7 +79,9 @@ struct sctp_packet *sctp_packet_config(struct sctp_packet *packet,
         packet->vtag = vtag;
         packet->has_cookie_echo = 0;
         packet->has_sack = 0;
+        packet->has_auth = 0;
         packet->ipfragok = 0;
+        packet->auth = NULL;
 
         if (ecn_capable && sctp_packet_empty(packet)) {
                 chunk = sctp_get_ecne_prepend(packet->transport->asoc);
@@ -121,8 +123,10 @@ struct sctp_packet *sctp_packet_init(struct sctp_packet *packet,
         packet->vtag = 0;
         packet->has_cookie_echo = 0;
         packet->has_sack = 0;
+        packet->has_auth = 0;
         packet->ipfragok = 0;
         packet->malloced = 0;
+        packet->auth = NULL;
         return packet;
 }
 
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 3ec8b12b6da4..4e6b59e8b695 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -1185,6 +1185,9 @@ SCTP_STATIC __init int sctp_init(void)
         /* Enable PR-SCTP by default. */
         sctp_prsctp_enable = 1;
 
+        /* Disable AUTH by default. */
+        sctp_auth_enable = 0;
+
         sctp_sysctl_register();
 
         INIT_LIST_HEAD(&sctp_address_families);
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index 39b10ee2f017..0669778e4335 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -254,6 +254,15 @@ static ctl_table sctp_table[] = {
                 .mode           = 0644,
                 .proc_handler   = &proc_dointvec,
         },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "auth_enable",
+                .data           = &sctp_auth_enable,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+                .strategy       = &sysctl_intvec
+        },
         { .ctl_name = 0 }
 };