Merge branch 'eap-constraints'

Introduces basic support for EAP server module authentication constraints. With
EAP-(T)TLS, public key, signature and end entity or CA certificate constraints
can be enforced for connections.

Fixes #762.

NEWS

@@ -22,6 +22,11 @@ strongswan-5.3.0
   Windows 7 IKEv2 clients, which announces its services over the tunnel if the
   negotiated IPsec policy allows it.
 
+- EAP server methods now can fulfill public key constraints, such as rightcert
+  or rightca. Additionally, public key and signature constraints can be
+  specified for EAP methods in the rightauth keyword. Currently the EAP-TLS and
+  EAP-TTLS methods provide verification details to constraints checking.
+
 - Upgrade of the BLISS post-quantum signature algorithm to the improved BLISS-B
   variant. Can be used in conjunction with the SHA256, SHA384 and SHA512 hash
   algorithms with SHA512 being the default.

man/ipsec.conf.5.in

@@ -614,7 +614,9 @@ Alternatively, IANA assigned EAP method numbers are accepted. Vendor specific
 EAP methods are defined in the form
 .B eap-type-vendor
 .RB "(e.g. " eap-7-12345 ).
-For
+To specify signature and trust chain constraints for EAP-(T)TLS, append a colon
+to the EAP method, followed by the key type/size and hash algorithm as discussed
+above. For
 .B xauth,
 an XAuth authentication backend can be specified, such as
 .B xauth-generic

src/libcharon/plugins/eap_tls/eap_tls.c

@@ -109,6 +109,12 @@ METHOD(eap_method_t, is_mutual, bool,
 	return TRUE;
 }
 
+METHOD(eap_method_t, get_auth, auth_cfg_t*,
+	private_eap_tls_t *this)
+{
+	return this->tls_eap->get_auth(this->tls_eap);
+}
+
 METHOD(eap_method_t, destroy, void,
 	private_eap_tls_t *this)
 {
@@ -138,6 +144,7 @@ static eap_tls_t *eap_tls_create(identification_t *server,
 				.get_msk = _get_msk,
 				.get_identifier = _get_identifier,
 				.set_identifier = _set_identifier,
+				.get_auth = _get_auth,
 				.destroy = _destroy,
 			},
 		},

src/libcharon/plugins/eap_ttls/eap_ttls.c

@@ -111,6 +111,12 @@ METHOD(eap_method_t, is_mutual, bool,
 	return TRUE;
 }
 
+METHOD(eap_method_t, get_auth, auth_cfg_t*,
+	private_eap_ttls_t *this)
+{
+	return this->tls_eap->get_auth(this->tls_eap);
+}
+
 METHOD(eap_method_t, destroy, void,
 	private_eap_ttls_t *this)
 {
@@ -141,6 +147,7 @@ static eap_ttls_t *eap_ttls_create(identification_t *server,
 				.get_identifier = _get_identifier,
 				.set_identifier = _set_identifier,
 				.get_msk = _get_msk,
+				.get_auth = _get_auth,
 				.destroy = _destroy,
 			},
 		},

src/libcharon/plugins/stroke/stroke_config.c

@@ -620,9 +620,16 @@ static auth_cfg_t *build_auth_cfg(private_stroke_config_t *this,
 	else if (strpfx(auth, "eap"))
 	{
 		eap_vendor_type_t *type;
+		char *pos;
 
 		cfg->add(cfg, AUTH_RULE_AUTH_CLASS, AUTH_CLASS_EAP);
-
+		/* check for public key constraints for EAP-TLS etc. */
+		pos = strchr(auth, ':');
+		if (pos)
+		{
+			*pos = 0;
+			parse_pubkey_constraints(pos + 1, cfg);
+		}
 		type = eap_vendor_type_from_string(auth);
 		if (type)
 		{

src/libcharon/sa/eap/eap_method.h

@@ -136,6 +136,18 @@ struct eap_method_t {
 	 */
 	void (*set_identifier) (eap_method_t *this, u_int8_t identifier);
 
+	/**
+	 * Get authentication details performed by this EAP method.
+	 *
+	 * After EAP completion, the auth data contains additional information
+	 * of the authentication process, used certificates etc.
+	 * This method is optional to implement, but if it is, it must return
+	 * a valid auth_cfg.
+	 *
+	 * @return				auth method, internal data
+	 */
+	auth_cfg_t* (*get_auth)(eap_method_t *this);
+
 	/**
 	 * Destroys a eap_method_t object.
 	 */

src/libcharon/sa/ikev2/authenticators/eap_authenticator.c

@@ -522,6 +522,13 @@ METHOD(authenticator_t, process_server, status_t,
 		{
 			return FAILED;
 		}
+		if (this->method->get_auth)
+		{
+			auth_cfg_t *auth;
+
+			auth = this->ike_sa->get_auth_cfg(this->ike_sa, FALSE);
+			auth->merge(auth, this->method->get_auth(this->method), FALSE);
+		}
 		return NEED_MORE;
 	}
 

src/libtls/tls.c

@@ -415,6 +415,12 @@ METHOD(tls_t, get_eap_msk, chunk_t,
 	return this->crypto->get_eap_msk(this->crypto);
 }
 
+METHOD(tls_t, get_auth, auth_cfg_t*,
+	private_tls_t *this)
+{
+	return this->handshake->get_auth(this->handshake);
+}
+
 METHOD(tls_t, destroy, void,
 	private_tls_t *this)
 {
@@ -465,6 +471,7 @@ tls_t *tls_create(bool is_server, identification_t *server,
 			.get_purpose = _get_purpose,
 			.is_complete = _is_complete,
 			.get_eap_msk = _get_eap_msk,
+			.get_auth = _get_auth,
 			.destroy = _destroy,
 		},
 		.is_server = is_server,

src/libtls/tls.h

@@ -251,6 +251,13 @@ struct tls_t {
 	 */
 	chunk_t (*get_eap_msk)(tls_t *this);
 
+	/**
+	 * Get the authentication details after completing the handshake.
+	 *
+	 * @return			authentication details, internal data
+	 */
+	auth_cfg_t* (*get_auth)(tls_t *this);
+
 	/**
 	 * Destroy a tls_t.
 	 */

src/libtls/tls_eap.c

@@ -426,6 +426,12 @@ METHOD(tls_eap_t, set_identifier, void,
 	this->identifier = identifier;
 }
 
+METHOD(tls_eap_t, get_auth, auth_cfg_t*,
+	private_tls_eap_t *this)
+{
+	return this->tls->get_auth(this->tls);
+}
+
 METHOD(tls_eap_t, destroy, void,
 	private_tls_eap_t *this)
 {
@@ -453,6 +459,7 @@ tls_eap_t *tls_eap_create(eap_type_t type, tls_t *tls, size_t frag_size,
 			.get_msk = _get_msk,
 			.get_identifier = _get_identifier,
 			.set_identifier = _set_identifier,
+			.get_auth = _get_auth,
 			.destroy = _destroy,
 		},
 		.type = type,

src/libtls/tls_eap.h

@@ -76,6 +76,13 @@ struct tls_eap_t {
 	 */
 	void (*set_identifier) (tls_eap_t *this, uint8_t identifier);
 
+	/**
+	 * Get the authentication details after completing the handshake.
+	 *
+	 * @return				authentication details, internal data
+	 */
+	auth_cfg_t* (*get_auth)(tls_eap_t *this);
+
 	/**
 	 * Destroy a tls_eap_t.
 	 */

src/libtls/tls_handshake.h

@@ -97,6 +97,13 @@ struct tls_handshake_t {
 	 */
 	identification_t* (*get_server_id)(tls_handshake_t *this);
 
+	/**
+	 * Get the peers authentication information after completing the handshake.
+	 *
+	 * @return			authentication data, internal data
+	 */
+	auth_cfg_t* (*get_auth)(tls_handshake_t *this);
+
 	/**
 	 * Destroy a tls_handshake_t.
 	 */

src/libtls/tls_peer.c

@@ -324,6 +324,7 @@ static public_key_t *find_public_key(private_tls_peer_t *this)
 		while (enumerator->enumerate(enumerator, &current, &auth))
 		{
 			public = current->get_ref(current);
+			this->server_auth->merge(this->server_auth, auth, FALSE);
 			break;
 		}
 		enumerator->destroy(enumerator);
@@ -1153,6 +1154,12 @@ METHOD(tls_handshake_t, get_server_id, identification_t*,
 	return this->server;
 }
 
+METHOD(tls_handshake_t, get_auth, auth_cfg_t*,
+	private_tls_peer_t *this)
+{
+	return this->server_auth;
+}
+
 METHOD(tls_handshake_t, destroy, void,
 	private_tls_peer_t *this)
 {
@@ -1186,6 +1193,7 @@ tls_peer_t *tls_peer_create(tls_t *tls, tls_crypto_t *crypto, tls_alert_t *alert
 				.finished = _finished,
 				.get_peer_id = _get_peer_id,
 				.get_server_id = _get_server_id,
+				.get_auth = _get_auth,
 				.destroy = _destroy,
 			},
 		},

src/libtls/tls_server.c

@@ -551,6 +551,7 @@ static status_t process_cert_verify(private_tls_server_t *this,
 		sig->destroy(sig);
 		if (verified)
 		{
+			this->peer_auth->merge(this->peer_auth, auth, FALSE);
 			break;
 		}
 		DBG1(DBG_TLS, "signature verification failed, trying another key");
@@ -1073,6 +1074,12 @@ METHOD(tls_handshake_t, get_server_id, identification_t*,
 	return this->server;
 }
 
+METHOD(tls_handshake_t, get_auth, auth_cfg_t*,
+	private_tls_server_t *this)
+{
+	return this->peer_auth;
+}
+
 METHOD(tls_handshake_t, destroy, void,
 	private_tls_server_t *this)
 {
@@ -1107,6 +1114,7 @@ tls_server_t *tls_server_create(tls_t *tls,
 				.finished = _finished,
 				.get_peer_id = _get_peer_id,
 				.get_server_id = _get_server_id,
+				.get_auth = _get_auth,
 				.destroy = _destroy,
 			},
 		},