[PATCH 17/26] sctp: Use HMAC-SHA1 and HMAC-SHA256 library functions
Eric Biggers
ebiggers at kernel.org
Sat Jul 12 16:23:08 PDT 2025
For SCTP authenticated chunks, use the HMAC-SHA1 and HMAC-SHA256 library
functions instead of crypto_shash. This is simpler and faster.
Signed-off-by: Eric Biggers <ebiggers at kernel.org>
---
include/net/sctp/auth.h | 12 +--
include/net/sctp/constants.h | 2 -
include/net/sctp/structs.h | 5 --
net/sctp/Kconfig | 15 ++--
net/sctp/auth.c | 153 +++++------------------------------
net/sctp/socket.c | 10 ---
6 files changed, 32 insertions(+), 165 deletions(-)
diff --git a/include/net/sctp/auth.h b/include/net/sctp/auth.h
index d4b3b2dcd15b7..02e13e126ceb7 100644
--- a/include/net/sctp/auth.h
+++ b/include/net/sctp/auth.h
@@ -20,20 +20,15 @@
struct sctp_endpoint;
struct sctp_association;
struct sctp_authkey;
struct sctp_hmacalgo;
-struct crypto_shash;
-/*
- * Define a generic struct that will hold all the info
- * necessary for an HMAC transform
- */
+/* Defines an HMAC algorithm supported by SCTP-AUTH */
struct sctp_hmac {
- __u16 hmac_id; /* one of the above ids */
- char *hmac_name; /* name for loading */
- __u16 hmac_len; /* length of the signature */
+ __u16 hmac_id; /* one of SCTP_AUTH_HMAC_ID_* */
+ __u16 hmac_len; /* length of the HMAC signature in bytes */
};
/* 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
@@ -76,11 +71,10 @@ struct sctp_shared_key *sctp_auth_get_shkey(
__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_shash *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,
diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index 5859e0a16a584..81dde3c3e6a58 100644
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -415,13 +415,11 @@ enum sctp_lower_cwnd {
*/
enum {
SCTP_AUTH_HMAC_ID_RESERVED_0,
SCTP_AUTH_HMAC_ID_SHA1,
SCTP_AUTH_HMAC_ID_RESERVED_2,
-#if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
SCTP_AUTH_HMAC_ID_SHA256,
-#endif
__SCTP_AUTH_HMAC_MAX
};
#define SCTP_AUTH_HMAC_ID_MAX __SCTP_AUTH_HMAC_MAX - 1
#define SCTP_AUTH_NUM_HMACS __SCTP_AUTH_HMAC_MAX
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 1ad7ce71d0a78..1de69a236754f 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1327,15 +1327,10 @@ struct sctp_endpoint {
__u32 sndbuf_policy;
/* 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_shash **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;
diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
index 24d5a35ce894a..192027555b4d8 100644
--- a/net/sctp/Kconfig
+++ b/net/sctp/Kconfig
@@ -5,13 +5,12 @@
menuconfig IP_SCTP
tristate "The SCTP Protocol"
depends on INET
depends on IPV6 || IPV6=n
- select CRYPTO
- select CRYPTO_HMAC
- select CRYPTO_SHA1
+ select CRYPTO_LIB_SHA1
+ select CRYPTO_LIB_SHA256
select NET_CRC32C
select NET_UDP_TUNNEL
help
Stream Control Transmission Protocol
@@ -77,19 +76,21 @@ endchoice
config SCTP_COOKIE_HMAC_MD5
bool "Enable optional MD5 hmac cookie generation"
help
Enable optional MD5 hmac based SCTP cookie generation
- select CRYPTO_HMAC if SCTP_COOKIE_HMAC_MD5
- select CRYPTO_MD5 if SCTP_COOKIE_HMAC_MD5
+ select CRYPTO
+ select CRYPTO_HMAC
+ select CRYPTO_MD5
config SCTP_COOKIE_HMAC_SHA1
bool "Enable optional SHA1 hmac cookie generation"
help
Enable optional SHA1 hmac based SCTP cookie generation
- select CRYPTO_HMAC if SCTP_COOKIE_HMAC_SHA1
- select CRYPTO_SHA1 if SCTP_COOKIE_HMAC_SHA1
+ select CRYPTO
+ select CRYPTO_HMAC
+ select CRYPTO_SHA1
config INET_SCTP_DIAG
depends on INET_DIAG
def_tristate INET_DIAG
diff --git a/net/sctp/auth.c b/net/sctp/auth.c
index c58fffc86a0c2..21d679a2ffb60 100644
--- a/net/sctp/auth.c
+++ b/net/sctp/auth.c
@@ -10,40 +10,41 @@
*
* Written or modified by:
* Vlad Yasevich <vladislav.yasevich at hp.com>
*/
-#include <crypto/hash.h>
+#include <crypto/sha1.h>
+#include <crypto/sha2.h>
#include <linux/slab.h>
#include <linux/types.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,
},
-#if IS_ENABLED(CONFIG_CRYPTO_SHA256)
{
.hmac_id = SCTP_AUTH_HMAC_ID_SHA256,
- .hmac_name = "hmac(sha256)",
.hmac_len = SCTP_SHA256_SIG_SIZE,
}
-#endif
};
+static bool sctp_hmac_supported(__u16 hmac_id)
+{
+ return hmac_id < ARRAY_SIZE(sctp_hmac_list) &&
+ sctp_hmac_list[hmac_id].hmac_len != 0;
+}
void sctp_auth_key_put(struct sctp_auth_bytes *key)
{
if (!key)
return;
@@ -442,79 +443,10 @@ struct sctp_shared_key *sctp_auth_get_shkey(
}
return NULL;
}
-/*
- * Initialize all the possible digest transforms that we can use. Right
- * 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_shash *tfm = NULL;
- __u16 id;
-
- /* If the transforms are already allocated, we are done */
- if (ep->auth_hmacs)
- return 0;
-
- /* Allocated the array of pointers to transorms */
- ep->auth_hmacs = kcalloc(SCTP_AUTH_NUM_HMACS,
- sizeof(struct crypto_shash *),
- 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_shash(sctp_hmac_list[id].hmac_name, 0, 0);
- if (IS_ERR(tfm))
- goto out_err;
-
- ep->auth_hmacs[id] = tfm;
- }
-
- return 0;
-
-out_err:
- /* Clean up any successful allocations */
- sctp_auth_destroy_hmacs(ep->auth_hmacs);
- ep->auth_hmacs = NULL;
- return -ENOMEM;
-}
-
-/* Destroy the hmac tfm array */
-void sctp_auth_destroy_hmacs(struct crypto_shash *auth_hmacs[])
-{
- int i;
-
- if (!auth_hmacs)
- return;
-
- for (i = 0; i < SCTP_AUTH_NUM_HMACS; i++) {
- crypto_free_shash(auth_hmacs[i]);
- }
- kfree(auth_hmacs);
-}
-
-
struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id)
{
return &sctp_hmac_list[hmac_id];
}
@@ -541,30 +473,14 @@ struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc)
n_elt = (ntohs(hmacs->param_hdr.length) -
sizeof(struct sctp_paramhdr)) >> 1;
for (i = 0; i < n_elt; i++) {
id = ntohs(hmacs->hmac_ids[i]);
-
- /* Check the id is in the supported range. And
- * see if we support the id. Supported IDs have name and
- * length fields set, so that we can allocate and use
- * them. We can safely just check for name, for without the
- * name, we can't allocate the TFM.
- */
- if (id > SCTP_AUTH_HMAC_ID_MAX ||
- !sctp_hmac_list[id].hmac_name) {
- id = 0;
- continue;
- }
-
- break;
+ if (sctp_hmac_supported(id))
+ return &sctp_hmac_list[id];
}
-
- if (id == 0)
- return NULL;
-
- return &sctp_hmac_list[id];
+ return NULL;
}
static int __sctp_auth_find_hmacid(__be16 *hmacs, int n_elts, __be16 hmac_id)
{
int found = 0;
@@ -604,31 +520,23 @@ int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
* 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(struct sctp_paramhdr)) >> 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]) {
+ if (sctp_hmac_supported(id)) {
asoc->default_hmac_id = id;
break;
}
}
}
@@ -707,13 +615,12 @@ int sctp_auth_recv_cid(enum sctp_cid 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,
struct sctp_shared_key *ep_key, gfp_t gfp)
{
struct sctp_auth_bytes *asoc_key;
- struct crypto_shash *tfm;
__u16 key_id, hmac_id;
- unsigned char *end;
+ size_t data_len;
int free_key = 0;
__u8 *digest;
/* Extract the info we need:
* - hmac id
@@ -731,23 +638,19 @@ void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
return;
free_key = 1;
}
- /* set up scatter list */
- end = skb_tail_pointer(skb);
-
- tfm = asoc->ep->auth_hmacs[hmac_id];
-
+ data_len = skb_tail_pointer(skb) - (u8 *)auth;
digest = (u8 *)(&auth->auth_hdr + 1);
- if (crypto_shash_setkey(tfm, &asoc_key->data[0], asoc_key->len))
- goto free;
-
- crypto_shash_tfm_digest(tfm, (u8 *)auth, end - (unsigned char *)auth,
- digest);
+ if (hmac_id == SCTP_AUTH_HMAC_ID_SHA1)
+ hmac_sha1_usingrawkey(asoc_key->data, asoc_key->len,
+ (u8 *)auth, data_len, digest);
+ else
+ hmac_sha256_usingrawkey(asoc_key->data, asoc_key->len,
+ (u8 *)auth, data_len, digest);
-free:
if (free_key)
sctp_auth_key_put(asoc_key);
}
/* API Helpers */
@@ -786,18 +689,15 @@ int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
* SHA1 is specified.
*/
for (i = 0; i < hmacs->shmac_num_idents; i++) {
id = hmacs->shmac_idents[i];
- if (id > SCTP_AUTH_HMAC_ID_MAX)
+ if (!sctp_hmac_supported(id))
return -EOPNOTSUPP;
if (SCTP_AUTH_HMAC_ID_SHA1 == id)
has_sha1 = 1;
-
- if (!sctp_hmac_list[id].hmac_name)
- return -EOPNOTSUPP;
}
if (!has_sha1)
return -EINVAL;
@@ -1019,12 +919,10 @@ int sctp_auth_deact_key_id(struct sctp_endpoint *ep,
return 0;
}
int sctp_auth_init(struct sctp_endpoint *ep, gfp_t gfp)
{
- int err = -ENOMEM;
-
/* 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.
*/
if (!ep->auth_hmacs_list) {
@@ -1058,32 +956,23 @@ int sctp_auth_init(struct sctp_endpoint *ep, gfp_t gfp)
auth_chunks->param_hdr.length =
htons(sizeof(struct sctp_paramhdr));
ep->auth_chunk_list = auth_chunks;
}
- /* Allocate and initialize transorms arrays for supported
- * HMACs.
- */
- err = sctp_auth_init_hmacs(ep, gfp);
- if (err)
- goto nomem;
-
return 0;
nomem:
/* Free all allocations */
kfree(ep->auth_hmacs_list);
kfree(ep->auth_chunk_list);
ep->auth_hmacs_list = NULL;
ep->auth_chunk_list = NULL;
- return err;
+ return -ENOMEM;
}
void sctp_auth_free(struct sctp_endpoint *ep)
{
kfree(ep->auth_hmacs_list);
kfree(ep->auth_chunk_list);
ep->auth_hmacs_list = NULL;
ep->auth_chunk_list = NULL;
- sctp_auth_destroy_hmacs(ep->auth_hmacs);
- ep->auth_hmacs = NULL;
}
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 1e5739858c206..1f3f1e7e1793b 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -9579,20 +9579,10 @@ static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
err = sctp_bind_addr_dup(&newsp->ep->base.bind_addr,
&oldsp->ep->base.bind_addr, GFP_KERNEL);
if (err)
return err;
- /* New ep's auth_hmacs should be set if old ep's is set, in case
- * that net->sctp.auth_enable has been changed to 0 by users and
- * new ep's auth_hmacs couldn't be set in sctp_endpoint_init().
- */
- if (oldsp->ep->auth_hmacs) {
- err = sctp_auth_init_hmacs(newsp->ep, GFP_KERNEL);
- if (err)
- return err;
- }
-
sctp_auto_asconf_init(newsp);
/* Move any messages in the old socket's receive queue that are for the
* peeled off association to the new socket's receive queue.
*/
--
2.50.1
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