[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>
git-mirror · Feb 1, 2008 · 1a6509d · 1a6509d
1 parent 6fbf2cb
commit 1a6509d
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Showing 7 changed files with 347 additions and 32 deletions.
diff --git a/include/linux/pfkeyv2.h b/include/linux/pfkeyv2.h
@@ -298,6 +298,12 @@ struct sadb_x_sec_ctx {
 #define SADB_X_EALG_BLOWFISHCBC		7
 #define SADB_EALG_NULL			11
 #define SADB_X_EALG_AESCBC		12
+#define SADB_X_EALG_AES_CCM_ICV8	14
+#define SADB_X_EALG_AES_CCM_ICV12	15
+#define SADB_X_EALG_AES_CCM_ICV16	16
+#define SADB_X_EALG_AES_GCM_ICV8	18
+#define SADB_X_EALG_AES_GCM_ICV12	19
+#define SADB_X_EALG_AES_GCM_ICV16	20
 #define SADB_X_EALG_CAMELLIACBC		22
 #define SADB_EALG_MAX                   253 /* last EALG */
 /* private allocations should use 249-255 (RFC2407) */

diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
@@ -96,6 +96,13 @@ struct xfrm_algo {
 	char		alg_key[0];
 };
 
+struct xfrm_algo_aead {
+	char	alg_name[64];
+	int	alg_key_len;	/* in bits */
+	int	alg_icv_len;	/* in bits */
+	char	alg_key[0];
+};
+
 struct xfrm_stats {
 	__u32	replay_window;
 	__u32	replay;
@@ -270,6 +277,7 @@ enum xfrm_attr_type_t {
 	XFRMA_LASTUSED,
 	XFRMA_POLICY_TYPE,	/* struct xfrm_userpolicy_type */
 	XFRMA_MIGRATE,
+	XFRMA_ALG_AEAD,		/* struct xfrm_algo_aead */
 	__XFRMA_MAX
 
 #define XFRMA_MAX (__XFRMA_MAX - 1)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
@@ -159,6 +159,7 @@ struct xfrm_state
 	struct xfrm_algo	*aalg;
 	struct xfrm_algo	*ealg;
 	struct xfrm_algo	*calg;
+	struct xfrm_algo_aead	*aead;
 
 	/* Data for encapsulator */
 	struct xfrm_encap_tmpl	*encap;
@@ -1108,6 +1109,10 @@ static inline int xfrm_id_proto_match(u8 proto, u8 userproto)
 /*
  * xfrm algorithm information
  */
+struct xfrm_algo_aead_info {
+	u16 icv_truncbits;
+};
+
 struct xfrm_algo_auth_info {
 	u16 icv_truncbits;
 	u16 icv_fullbits;
@@ -1127,6 +1132,7 @@ struct xfrm_algo_desc {
 	char *compat;
 	u8 available:1;
 	union {
+		struct xfrm_algo_aead_info aead;
 		struct xfrm_algo_auth_info auth;
 		struct xfrm_algo_encr_info encr;
 		struct xfrm_algo_comp_info comp;
@@ -1343,6 +1349,8 @@ extern struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id);
 extern struct xfrm_algo_desc *xfrm_aalg_get_byname(char *name, int probe);
 extern struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name, int probe);
 extern struct xfrm_algo_desc *xfrm_calg_get_byname(char *name, int probe);
+extern struct xfrm_algo_desc *xfrm_aead_get_byname(char *name, int icv_len,
+						   int probe);
 
 struct hash_desc;
 struct scatterlist;

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
@@ -439,32 +439,53 @@ static void esp_destroy(struct xfrm_state *x)
 	kfree(esp);
 }
 
-static int esp_init_state(struct xfrm_state *x)
+static int esp_init_aead(struct xfrm_state *x)
 {
-	struct esp_data *esp = NULL;
+	struct esp_data *esp = x->data;
+	struct crypto_aead *aead;
+	int err;
+
+	aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
+	err = PTR_ERR(aead);
+	if (IS_ERR(aead))
+		goto error;
+
+	esp->aead = aead;
+
+	err = crypto_aead_setkey(aead, x->aead->alg_key,
+				 (x->aead->alg_key_len + 7) / 8);
+	if (err)
+		goto error;
+
+	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
+	if (err)
+		goto error;
+
+error:
+	return err;
+}
+
+static int esp_init_authenc(struct xfrm_state *x)
+{
+	struct esp_data *esp = x->data;
 	struct crypto_aead *aead;
 	struct crypto_authenc_key_param *param;
 	struct rtattr *rta;
 	char *key;
 	char *p;
 	char authenc_name[CRYPTO_MAX_ALG_NAME];
-	u32 align;
 	unsigned int keylen;
 	int err;
 
+	err = -EINVAL;
 	if (x->ealg == NULL)
-		return -EINVAL;
+		goto error;
 
+	err = -ENAMETOOLONG;
 	if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, "authenc(%s,%s)",
 		     x->aalg ? x->aalg->alg_name : "digest_null",
 		     x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
-		return -ENAMETOOLONG;
-
-	esp = kzalloc(sizeof(*esp), GFP_KERNEL);
-	if (esp == NULL)
-		return -ENOMEM;
-
-	x->data = esp;
+		goto error;
 
 	aead = crypto_alloc_aead(authenc_name, 0, 0);
 	err = PTR_ERR(aead);
@@ -512,8 +533,6 @@ static int esp_init_state(struct xfrm_state *x)
 			goto free_key;
 	}
 
-	esp->padlen = 0;
-
 	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
 	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
 
@@ -522,9 +541,35 @@ static int esp_init_state(struct xfrm_state *x)
 free_key:
 	kfree(key);
 
+error:
+	return err;
+}
+
+static int esp_init_state(struct xfrm_state *x)
+{
+	struct esp_data *esp;
+	struct crypto_aead *aead;
+	u32 align;
+	int err;
+
+	esp = kzalloc(sizeof(*esp), GFP_KERNEL);
+	if (esp == NULL)
+		return -ENOMEM;
+
+	x->data = esp;
+
+	if (x->aead)
+		err = esp_init_aead(x);
+	else
+		err = esp_init_authenc(x);
+
 	if (err)
 		goto error;
 
+	aead = esp->aead;
+
+	esp->padlen = 0;
+
 	x->props.header_len = sizeof(struct ip_esp_hdr) +
 			      crypto_aead_ivsize(aead);
 	if (x->props.mode == XFRM_MODE_TUNNEL)

diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
@@ -382,35 +382,53 @@ static void esp6_destroy(struct xfrm_state *x)
 	kfree(esp);
 }
 
-static int esp6_init_state(struct xfrm_state *x)
+static int esp_init_aead(struct xfrm_state *x)
+{
+	struct esp_data *esp = x->data;
+	struct crypto_aead *aead;
+	int err;
+
+	aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
+	err = PTR_ERR(aead);
+	if (IS_ERR(aead))
+		goto error;
+
+	esp->aead = aead;
+
+	err = crypto_aead_setkey(aead, x->aead->alg_key,
+				 (x->aead->alg_key_len + 7) / 8);
+	if (err)
+		goto error;
+
+	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
+	if (err)
+		goto error;
+
+error:
+	return err;
+}
+
+static int esp_init_authenc(struct xfrm_state *x)
 {
-	struct esp_data *esp = NULL;
+	struct esp_data *esp = x->data;
 	struct crypto_aead *aead;
 	struct crypto_authenc_key_param *param;
 	struct rtattr *rta;
 	char *key;
 	char *p;
 	char authenc_name[CRYPTO_MAX_ALG_NAME];
-	u32 align;
 	unsigned int keylen;
 	int err;
 
+	err = -EINVAL;
 	if (x->ealg == NULL)
-		return -EINVAL;
-
-	if (x->encap)
-		return -EINVAL;
+		goto error;
 
+	err = -ENAMETOOLONG;
 	if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, "authenc(%s,%s)",
 		     x->aalg ? x->aalg->alg_name : "digest_null",
 		     x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
-		return -ENAMETOOLONG;
-
-	esp = kzalloc(sizeof(*esp), GFP_KERNEL);
-	if (esp == NULL)
-		return -ENOMEM;
-
-	x->data = esp;
+		goto error;
 
 	aead = crypto_alloc_aead(authenc_name, 0, 0);
 	err = PTR_ERR(aead);
@@ -458,8 +476,6 @@ static int esp6_init_state(struct xfrm_state *x)
 			goto free_key;
 	}
 
-	esp->padlen = 0;
-
 	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
 	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
 
@@ -468,9 +484,38 @@ static int esp6_init_state(struct xfrm_state *x)
 free_key:
 	kfree(key);
 
+error:
+	return err;
+}
+
+static int esp6_init_state(struct xfrm_state *x)
+{
+	struct esp_data *esp;
+	struct crypto_aead *aead;
+	u32 align;
+	int err;
+
+	if (x->encap)
+		return -EINVAL;
+
+	esp = kzalloc(sizeof(*esp), GFP_KERNEL);
+	if (esp == NULL)
+		return -ENOMEM;
+
+	x->data = esp;
+
+	if (x->aead)
+		err = esp_init_aead(x);
+	else
+		err = esp_init_authenc(x);
+
 	if (err)
 		goto error;
 
+	aead = esp->aead;
+
+	esp->padlen = 0;
+
 	x->props.header_len = sizeof(struct ip_esp_hdr) +
 			      crypto_aead_ivsize(aead);
 	switch (x->props.mode) {