[IPSEC]: Add support for combined mode algorithms
This patch adds support for combined mode algorithms with GCM being
the first algorithm supported.
Combined mode algorithms can be added through the xfrm_user interface
using the new algorithm payload type XFRMA_ALG_AEAD. Each algorithms
is identified by its name and the ICV length.
For the purposes of matching algorithms in xfrm_tmpl structures,
combined mode algorithms occupy the same name space as encryption
algorithms. This is in line with how they are negotiated using IKE.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index e0ccdf2..7833807 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -31,6 +31,11 @@
#include <linux/in6.h>
#endif
+static inline int aead_len(struct xfrm_algo_aead *alg)
+{
+ return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
+}
+
static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type)
{
struct nlattr *rt = attrs[type];
@@ -68,6 +73,22 @@
return 0;
}
+static int verify_aead(struct nlattr **attrs)
+{
+ struct nlattr *rt = attrs[XFRMA_ALG_AEAD];
+ struct xfrm_algo_aead *algp;
+
+ if (!rt)
+ return 0;
+
+ algp = nla_data(rt);
+ if (nla_len(rt) < aead_len(algp))
+ return -EINVAL;
+
+ algp->alg_name[CRYPTO_MAX_ALG_NAME - 1] = '\0';
+ return 0;
+}
+
static void verify_one_addr(struct nlattr **attrs, enum xfrm_attr_type_t type,
xfrm_address_t **addrp)
{
@@ -119,20 +140,28 @@
switch (p->id.proto) {
case IPPROTO_AH:
if (!attrs[XFRMA_ALG_AUTH] ||
+ attrs[XFRMA_ALG_AEAD] ||
attrs[XFRMA_ALG_CRYPT] ||
attrs[XFRMA_ALG_COMP])
goto out;
break;
case IPPROTO_ESP:
- if ((!attrs[XFRMA_ALG_AUTH] &&
- !attrs[XFRMA_ALG_CRYPT]) ||
- attrs[XFRMA_ALG_COMP])
+ if (attrs[XFRMA_ALG_COMP])
+ goto out;
+ if (!attrs[XFRMA_ALG_AUTH] &&
+ !attrs[XFRMA_ALG_CRYPT] &&
+ !attrs[XFRMA_ALG_AEAD])
+ goto out;
+ if ((attrs[XFRMA_ALG_AUTH] ||
+ attrs[XFRMA_ALG_CRYPT]) &&
+ attrs[XFRMA_ALG_AEAD])
goto out;
break;
case IPPROTO_COMP:
if (!attrs[XFRMA_ALG_COMP] ||
+ attrs[XFRMA_ALG_AEAD] ||
attrs[XFRMA_ALG_AUTH] ||
attrs[XFRMA_ALG_CRYPT])
goto out;
@@ -143,6 +172,7 @@
case IPPROTO_ROUTING:
if (attrs[XFRMA_ALG_COMP] ||
attrs[XFRMA_ALG_AUTH] ||
+ attrs[XFRMA_ALG_AEAD] ||
attrs[XFRMA_ALG_CRYPT] ||
attrs[XFRMA_ENCAP] ||
attrs[XFRMA_SEC_CTX] ||
@@ -155,6 +185,8 @@
goto out;
}
+ if ((err = verify_aead(attrs)))
+ goto out;
if ((err = verify_one_alg(attrs, XFRMA_ALG_AUTH)))
goto out;
if ((err = verify_one_alg(attrs, XFRMA_ALG_CRYPT)))
@@ -208,6 +240,31 @@
return 0;
}
+static int attach_aead(struct xfrm_algo_aead **algpp, u8 *props,
+ struct nlattr *rta)
+{
+ struct xfrm_algo_aead *p, *ualg;
+ struct xfrm_algo_desc *algo;
+
+ if (!rta)
+ return 0;
+
+ ualg = nla_data(rta);
+
+ algo = xfrm_aead_get_byname(ualg->alg_name, ualg->alg_icv_len, 1);
+ if (!algo)
+ return -ENOSYS;
+ *props = algo->desc.sadb_alg_id;
+
+ p = kmemdup(ualg, aead_len(ualg), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ strcpy(p->alg_name, algo->name);
+ *algpp = p;
+ return 0;
+}
+
static inline int xfrm_user_sec_ctx_size(struct xfrm_sec_ctx *xfrm_ctx)
{
int len = 0;
@@ -286,6 +343,9 @@
copy_from_user_state(x, p);
+ if ((err = attach_aead(&x->aead, &x->props.ealgo,
+ attrs[XFRMA_ALG_AEAD])))
+ goto error;
if ((err = attach_one_algo(&x->aalg, &x->props.aalgo,
xfrm_aalg_get_byname,
attrs[XFRMA_ALG_AUTH])))
@@ -510,6 +570,8 @@
if (x->lastused)
NLA_PUT_U64(skb, XFRMA_LASTUSED, x->lastused);
+ if (x->aead)
+ NLA_PUT(skb, XFRMA_ALG_AEAD, aead_len(x->aead), x->aead);
if (x->aalg)
NLA_PUT(skb, XFRMA_ALG_AUTH, xfrm_alg_len(x->aalg), x->aalg);
if (x->ealg)
@@ -1808,6 +1870,7 @@
#undef XMSGSIZE
static const struct nla_policy xfrma_policy[XFRMA_MAX+1] = {
+ [XFRMA_ALG_AEAD] = { .len = sizeof(struct xfrm_algo_aead) },
[XFRMA_ALG_AUTH] = { .len = sizeof(struct xfrm_algo) },
[XFRMA_ALG_CRYPT] = { .len = sizeof(struct xfrm_algo) },
[XFRMA_ALG_COMP] = { .len = sizeof(struct xfrm_algo) },
@@ -1972,6 +2035,8 @@
static inline size_t xfrm_sa_len(struct xfrm_state *x)
{
size_t l = 0;
+ if (x->aead)
+ l += nla_total_size(aead_len(x->aead));
if (x->aalg)
l += nla_total_size(xfrm_alg_len(x->aalg));
if (x->ealg)