net: sctp: remove unused multiple cookie keys

Vlad says: The whole multiple cookie keys code is completely unused
and has been all this time. Noone uses anything other then the
secret_key[0] since there is no changeover support anywhere.

Thus, for now clean up its left-over fragments.

Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 11 insertions, 36 deletions

diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index c29707d654c0..a7dd5c50df79 100644
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -303,7 +303,7 @@ enum { SCTP_MAX_GABS = 16 };
                                          * to which we will raise the P-MTU.
                                          */
 #define SCTP_DEFAULT_MINSEGMENT 512     /* MTU size ... if no mtu disc */
-#define SCTP_HOW_MANY_SECRETS 2         /* How many secrets I keep */
+
 #define SCTP_SECRET_SIZE 32             /* Number of octets in a 256 bits. */
 
 #define SCTP_SIGNATURE_SIZE 20          /* size of a SLA-1 signature */
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index fdeb85a970fc..0e0f9d2322e3 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1236,10 +1236,7 @@ struct sctp_endpoint {
          *            Discussion in [RFC1750] can be helpful in
          *            selection of the key.
          */
-        __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
-        int current_key;
-        int last_key;
-        int key_changed_at;
+        __u8 secret_key[SCTP_SECRET_SIZE];
 
         /* digest:  This is a digest of the sctp cookie.  This field is
          *          only used on the receive path when we try to validate
diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index 1a9c5fb77310..73aad3d16a45 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -151,9 +151,7 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
         ep->rcvbuf_policy = net->sctp.rcvbuf_policy;
 
         /* Initialize the secret key used with cookie. */
-        get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
-        ep->last_key = ep->current_key = 0;
-        ep->key_changed_at = jiffies;
+        get_random_bytes(ep->secret_key, sizeof(ep->secret_key));
 
         /* SCTP-AUTH extensions*/
         INIT_LIST_HEAD(&ep->endpoint_shared_keys);
@@ -249,8 +247,6 @@ void sctp_endpoint_free(struct sctp_endpoint *ep)
 /* Final destructor for endpoint.  */
 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 {
-        int i;
-
         SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
 
         /* Free up the HMAC transform. */
@@ -273,8 +269,7 @@ static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
         sctp_inq_free(&ep->base.inqueue);
         sctp_bind_addr_free(&ep->base.bind_addr);
 
-        for (i = 0; i < SCTP_HOW_MANY_SECRETS; ++i)
-                memset(&ep->secret_key[i], 0, SCTP_SECRET_SIZE);
+        memset(ep->secret_key, 0, sizeof(ep->secret_key));
 
         /* Remove and free the port */
         if (sctp_sk(ep->base.sk)->bind_hash)
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index e1c5fc2be6b8..a193f3bc8144 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1589,8 +1589,6 @@ static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
         struct sctp_signed_cookie *cookie;
         struct scatterlist sg;
         int headersize, bodysize;
-        unsigned int keylen;
-        char *key;
 
         /* Header size is static data prior to the actual cookie, including
          * any padding.
@@ -1650,12 +1648,11 @@ static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
 
                 /* Sign the message.  */
                 sg_init_one(&sg, &cookie->c, bodysize);
-                keylen = SCTP_SECRET_SIZE;
-                key = (char *)ep->secret_key[ep->current_key];
                 desc.tfm = sctp_sk(ep->base.sk)->hmac;
                 desc.flags = 0;
 
-                if (crypto_hash_setkey(desc.tfm, key, keylen) ||
+                if (crypto_hash_setkey(desc.tfm, ep->secret_key,
+                                       sizeof(ep->secret_key)) ||
                     crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
                         goto free_cookie;
         }
@@ -1682,8 +1679,7 @@ struct sctp_association *sctp_unpack_cookie(
         int headersize, bodysize, fixed_size;
         __u8 *digest = ep->digest;
         struct scatterlist sg;
-        unsigned int keylen, len;
-        char *key;
+        unsigned int len;
         sctp_scope_t scope;
         struct sk_buff *skb = chunk->skb;
         struct timeval tv;
@@ -1718,34 +1714,21 @@ struct sctp_association *sctp_unpack_cookie(
                 goto no_hmac;
 
         /* Check the signature.  */
-        keylen = SCTP_SECRET_SIZE;
         sg_init_one(&sg, bear_cookie, bodysize);
-        key = (char *)ep->secret_key[ep->current_key];
         desc.tfm = sctp_sk(ep->base.sk)->hmac;
         desc.flags = 0;
 
         memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
-        if (crypto_hash_setkey(desc.tfm, key, keylen) ||
+        if (crypto_hash_setkey(desc.tfm, ep->secret_key,
+                               sizeof(ep->secret_key)) ||
             crypto_hash_digest(&desc, &sg, bodysize, digest)) {
                 *error = -SCTP_IERROR_NOMEM;
                 goto fail;
         }
 
         if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
-                /* Try the previous key. */
-                key = (char *)ep->secret_key[ep->last_key];
-                memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
-                if (crypto_hash_setkey(desc.tfm, key, keylen) ||
-                    crypto_hash_digest(&desc, &sg, bodysize, digest)) {
-                        *error = -SCTP_IERROR_NOMEM;
-                        goto fail;
-                }
-
-                if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
-                        /* Yikes!  Still bad signature! */
-                        *error = -SCTP_IERROR_BAD_SIG;
-                        goto fail;
-                }
+                *error = -SCTP_IERROR_BAD_SIG;
+                goto fail;
         }
 
 no_hmac: