macsec: restore uAPI after addition of GCM-AES-256

Commit ccfdec9089 ("macsec: Add support for GCM-AES-256 cipher suite")
changed a few values in the uapi headers for MACsec.

Because of existing userspace implementations, we need to preserve the
value of MACSEC_DEFAULT_CIPHER_ID. Not doing that resulted in
wpa_supplicant segfaults when a secure channel was created using the
default cipher. Thus, swap MACSEC_DEFAULT_CIPHER_{ID,ALT} back to their
original values.

Changing the maximum length of the MACSEC_SA_ATTR_KEY attribute is
unnecessary, as the previous value (MACSEC_MAX_KEY_LEN, which was 128B)
is large enough to carry 32-bytes keys. This patch reverts
MACSEC_MAX_KEY_LEN to 128B and restores the old length check on
MACSEC_SA_ATTR_KEY.

Fixes: ccfdec9089 ("macsec: Add support for GCM-AES-256 cipher suite")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sabrina Dubroca 2018-01-18 17:48:18 +01:00 committed by David S. Miller
parent 5e89cfac2e
commit e8660ded7f
2 changed files with 8 additions and 10 deletions

View File

@ -396,8 +396,6 @@ static struct macsec_cb *macsec_skb_cb(struct sk_buff *skb)
#define MACSEC_GCM_AES_128_SAK_LEN 16 #define MACSEC_GCM_AES_128_SAK_LEN 16
#define MACSEC_GCM_AES_256_SAK_LEN 32 #define MACSEC_GCM_AES_256_SAK_LEN 32
#define MAX_SAK_LEN MACSEC_GCM_AES_256_SAK_LEN
#define DEFAULT_SAK_LEN MACSEC_GCM_AES_128_SAK_LEN #define DEFAULT_SAK_LEN MACSEC_GCM_AES_128_SAK_LEN
#define DEFAULT_SEND_SCI true #define DEFAULT_SEND_SCI true
#define DEFAULT_ENCRYPT false #define DEFAULT_ENCRYPT false
@ -1605,7 +1603,7 @@ static const struct nla_policy macsec_genl_sa_policy[NUM_MACSEC_SA_ATTR] = {
[MACSEC_SA_ATTR_KEYID] = { .type = NLA_BINARY, [MACSEC_SA_ATTR_KEYID] = { .type = NLA_BINARY,
.len = MACSEC_KEYID_LEN, }, .len = MACSEC_KEYID_LEN, },
[MACSEC_SA_ATTR_KEY] = { .type = NLA_BINARY, [MACSEC_SA_ATTR_KEY] = { .type = NLA_BINARY,
.len = MAX_SAK_LEN, }, .len = MACSEC_MAX_KEY_LEN, },
}; };
static int parse_sa_config(struct nlattr **attrs, struct nlattr **tb_sa) static int parse_sa_config(struct nlattr **attrs, struct nlattr **tb_sa)
@ -2374,7 +2372,7 @@ static int nla_put_secy(struct macsec_secy *secy, struct sk_buff *skb)
switch (secy->key_len) { switch (secy->key_len) {
case MACSEC_GCM_AES_128_SAK_LEN: case MACSEC_GCM_AES_128_SAK_LEN:
csid = MACSEC_CIPHER_ID_GCM_AES_128; csid = MACSEC_DEFAULT_CIPHER_ID;
break; break;
case MACSEC_GCM_AES_256_SAK_LEN: case MACSEC_GCM_AES_256_SAK_LEN:
csid = MACSEC_CIPHER_ID_GCM_AES_256; csid = MACSEC_CIPHER_ID_GCM_AES_256;
@ -3076,7 +3074,7 @@ static int macsec_changelink_common(struct net_device *dev,
if (data[IFLA_MACSEC_CIPHER_SUITE]) { if (data[IFLA_MACSEC_CIPHER_SUITE]) {
switch (nla_get_u64(data[IFLA_MACSEC_CIPHER_SUITE])) { switch (nla_get_u64(data[IFLA_MACSEC_CIPHER_SUITE])) {
case MACSEC_CIPHER_ID_GCM_AES_128: case MACSEC_CIPHER_ID_GCM_AES_128:
case MACSEC_DEFAULT_CIPHER_ALT: case MACSEC_DEFAULT_CIPHER_ID:
secy->key_len = MACSEC_GCM_AES_128_SAK_LEN; secy->key_len = MACSEC_GCM_AES_128_SAK_LEN;
break; break;
case MACSEC_CIPHER_ID_GCM_AES_256: case MACSEC_CIPHER_ID_GCM_AES_256:
@ -3355,7 +3353,7 @@ static int macsec_validate_attr(struct nlattr *tb[], struct nlattr *data[],
switch (csid) { switch (csid) {
case MACSEC_CIPHER_ID_GCM_AES_128: case MACSEC_CIPHER_ID_GCM_AES_128:
case MACSEC_CIPHER_ID_GCM_AES_256: case MACSEC_CIPHER_ID_GCM_AES_256:
case MACSEC_DEFAULT_CIPHER_ALT: case MACSEC_DEFAULT_CIPHER_ID:
if (icv_len < MACSEC_MIN_ICV_LEN || if (icv_len < MACSEC_MIN_ICV_LEN ||
icv_len > MACSEC_STD_ICV_LEN) icv_len > MACSEC_STD_ICV_LEN)
return -EINVAL; return -EINVAL;
@ -3428,7 +3426,7 @@ static int macsec_fill_info(struct sk_buff *skb,
switch (secy->key_len) { switch (secy->key_len) {
case MACSEC_GCM_AES_128_SAK_LEN: case MACSEC_GCM_AES_128_SAK_LEN:
csid = MACSEC_CIPHER_ID_GCM_AES_128; csid = MACSEC_DEFAULT_CIPHER_ID;
break; break;
case MACSEC_GCM_AES_256_SAK_LEN: case MACSEC_GCM_AES_256_SAK_LEN:
csid = MACSEC_CIPHER_ID_GCM_AES_256; csid = MACSEC_CIPHER_ID_GCM_AES_256;

View File

@ -18,7 +18,7 @@
#define MACSEC_GENL_NAME "macsec" #define MACSEC_GENL_NAME "macsec"
#define MACSEC_GENL_VERSION 1 #define MACSEC_GENL_VERSION 1
#define MACSEC_MAX_KEY_LEN 256 #define MACSEC_MAX_KEY_LEN 128
#define MACSEC_KEYID_LEN 16 #define MACSEC_KEYID_LEN 16
@ -26,9 +26,9 @@
#define MACSEC_CIPHER_ID_GCM_AES_128 0x0080C20001000001ULL #define MACSEC_CIPHER_ID_GCM_AES_128 0x0080C20001000001ULL
#define MACSEC_CIPHER_ID_GCM_AES_256 0x0080C20001000002ULL #define MACSEC_CIPHER_ID_GCM_AES_256 0x0080C20001000002ULL
#define MACSEC_DEFAULT_CIPHER_ID MACSEC_CIPHER_ID_GCM_AES_128
/* deprecated cipher ID for GCM-AES-128 */ /* deprecated cipher ID for GCM-AES-128 */
#define MACSEC_DEFAULT_CIPHER_ALT 0x0080020001000001ULL #define MACSEC_DEFAULT_CIPHER_ID 0x0080020001000001ULL
#define MACSEC_DEFAULT_CIPHER_ALT MACSEC_CIPHER_ID_GCM_AES_128
#define MACSEC_MIN_ICV_LEN 8 #define MACSEC_MIN_ICV_LEN 8
#define MACSEC_MAX_ICV_LEN 32 #define MACSEC_MAX_ICV_LEN 32