RADIUS server: Add support for MAC ACL

"user" MACACL "password" style lines in the eap_user file can now be
used to configured user entries for RADIUS-based MAC ACL.

Signed-off-by: Jouni Malinen <j@w1.fi>

hostapd/config_file.c

@@ -366,6 +366,10 @@ static int hostapd_config_read_eap_user(const char *fname,
 						EAP_TTLS_AUTH_MSCHAPV2;
 					goto skip_eap;
 				}
+				if (os_strcmp(start, "MACACL") == 0) {
+					user->macacl = 1;
+					goto skip_eap;
+				}
 				wpa_printf(MSG_ERROR, "Unsupported EAP type "
 					   "'%s' on line %d in '%s'",
 					   start, line, fname);
@@ -380,7 +384,7 @@ static int hostapd_config_read_eap_user(const char *fname,
 				break;
 			start = pos3;
 		}
-		if (num_methods == 0 && user->ttls_auth == 0) {
+		if (num_methods == 0 && user->ttls_auth == 0 && !user->macacl) {
 			wpa_printf(MSG_ERROR, "No EAP types configured on "
 				   "line %d in '%s'", line, fname);
 			goto failed;

src/ap/ap_config.h

@@ -127,6 +127,7 @@ struct hostapd_eap_user {
 	unsigned int password_hash:1; /* whether password is hashed with
 				       * nt_password_hash() */
 	unsigned int remediation:1;
+	unsigned int macacl:1;
 	int ttls_auth; /* EAP_TTLS_AUTH_* bitfield */
 	struct hostapd_radius_attr *accept_attr;
 };

src/ap/authsrv.c

@@ -79,6 +79,7 @@ static int hostapd_radius_get_eap_user(void *ctx, const u8 *identity,
 		user->password_hash = eap_user->password_hash;
 	}
 	user->force_version = eap_user->force_version;
+	user->macacl = eap_user->macacl;
 	user->ttls_auth = eap_user->ttls_auth;
 	user->remediation = eap_user->remediation;
 	user->accept_attr = eap_user->accept_attr;

src/ap/ieee802_1x.c

@@ -1787,6 +1787,7 @@ static int ieee802_1x_get_eap_user(void *ctx, const u8 *identity,
 		user->password_hash = eap_user->password_hash;
 	}
 	user->force_version = eap_user->force_version;
+	user->macacl = eap_user->macacl;
 	user->ttls_auth = eap_user->ttls_auth;
 	user->remediation = eap_user->remediation;
 

src/eap_server/eap.h

@@ -33,6 +33,7 @@ struct eap_user {
 	int phase2;
 	int force_version;
 	unsigned int remediation:1;
+	unsigned int macacl:1;
 	int ttls_auth; /* bitfield of
 			* EAP_TTLS_AUTH_{PAP,CHAP,MSCHAP,MSCHAPV2} */
 	struct hostapd_radius_attr *accept_attr;

src/radius/radius.c

@@ -1247,30 +1247,28 @@ int radius_msg_add_wfa(struct radius_msg *msg, u8 subtype, const u8 *data,
 }
 
 
-/* Add User-Password attribute to a RADIUS message and encrypt it as specified
- * in RFC 2865, Chap. 5.2 */
-struct radius_attr_hdr *
-radius_msg_add_attr_user_password(struct radius_msg *msg,
-				  const u8 *data, size_t data_len,
-				  const u8 *secret, size_t secret_len)
+int radius_user_password_hide(struct radius_msg *msg,
+			      const u8 *data, size_t data_len,
+			      const u8 *secret, size_t secret_len,
+			      u8 *buf, size_t buf_len)
 {
-	u8 buf[128];
-	size_t padlen, i, buf_len, pos;
+	size_t padlen, i, pos;
 	const u8 *addr[2];
 	size_t len[2];
 	u8 hash[16];
 
-	if (data_len > 128)
-		return NULL;
+	if (data_len + 16 > buf_len)
+		return -1;
 
 	os_memcpy(buf, data, data_len);
-	buf_len = data_len;
 
 	padlen = data_len % 16;
-	if (padlen && data_len < sizeof(buf)) {
+	if (padlen && data_len < buf_len) {
 		padlen = 16 - padlen;
 		os_memset(buf + data_len, 0, padlen);
-		buf_len += padlen;
+		buf_len = data_len + padlen;
+	} else {
+		buf_len = data_len;
 	}
 
 	addr[0] = secret;
@@ -1296,8 +1294,27 @@ radius_msg_add_attr_user_password(struct radius_msg *msg,
 		pos += 16;
 	}
 
+	return buf_len;
+}
+
+
+/* Add User-Password attribute to a RADIUS message and encrypt it as specified
+ * in RFC 2865, Chap. 5.2 */
+struct radius_attr_hdr *
+radius_msg_add_attr_user_password(struct radius_msg *msg,
+				  const u8 *data, size_t data_len,
+				  const u8 *secret, size_t secret_len)
+{
+	u8 buf[128];
+	int res;
+
+	res = radius_user_password_hide(msg, data, data_len,
+					secret, secret_len, buf, sizeof(buf));
+	if (res < 0)
+		return NULL;
+
 	return radius_msg_add_attr(msg, RADIUS_ATTR_USER_PASSWORD,
-				   buf, buf_len);
+				   buf, res);
 }
 
 

src/radius/radius.h

@@ -251,6 +251,10 @@ int radius_msg_add_mppe_keys(struct radius_msg *msg,
 			     const u8 *recv_key, size_t recv_key_len);
 int radius_msg_add_wfa(struct radius_msg *msg, u8 subtype, const u8 *data,
 		       size_t len);
+int radius_user_password_hide(struct radius_msg *msg,
+			      const u8 *data, size_t data_len,
+			      const u8 *secret, size_t secret_len,
+			      u8 *buf, size_t buf_len);
 struct radius_attr_hdr *
 radius_msg_add_attr_user_password(struct radius_msg *msg,
 				  const u8 *data, size_t data_len,

src/radius/radius_server.c

@@ -86,6 +86,7 @@ struct radius_session {
 	u8 last_authenticator[16];
 
 	unsigned int remediation:1;
+	unsigned int macacl:1;
 
 	struct hostapd_radius_attr *accept_attr;
 };
@@ -636,6 +637,7 @@ radius_server_get_new_session(struct radius_server_data *data,
 		return NULL;
 	}
 	sess->accept_attr = tmp.accept_attr;
+	sess->macacl = tmp.macacl;
 
 	sess->username = os_malloc(user_len * 2 + 1);
 	if (sess->username == NULL) {
@@ -823,6 +825,87 @@ radius_server_encapsulate_eap(struct radius_server_data *data,
 }
 
 
+static struct radius_msg *
+radius_server_macacl(struct radius_server_data *data,
+		     struct radius_client *client,
+		     struct radius_session *sess,
+		     struct radius_msg *request)
+{
+	struct radius_msg *msg;
+	int code;
+	struct radius_hdr *hdr = radius_msg_get_hdr(request);
+	u8 *pw;
+	size_t pw_len;
+
+	code = RADIUS_CODE_ACCESS_ACCEPT;
+
+	if (radius_msg_get_attr_ptr(request, RADIUS_ATTR_USER_PASSWORD, &pw,
+				    &pw_len, NULL) < 0) {
+		RADIUS_DEBUG("Could not get User-Password");
+		code = RADIUS_CODE_ACCESS_REJECT;
+	} else {
+		int res;
+		struct eap_user tmp;
+
+		os_memset(&tmp, 0, sizeof(tmp));
+		res = data->get_eap_user(data->conf_ctx, (u8 *) sess->username,
+					 os_strlen(sess->username), 0, &tmp);
+		if (res || !tmp.macacl || tmp.password == NULL) {
+			RADIUS_DEBUG("No MAC ACL user entry");
+			os_free(tmp.password);
+			code = RADIUS_CODE_ACCESS_REJECT;
+		} else {
+			u8 buf[128];
+			res = radius_user_password_hide(
+				request, tmp.password, tmp.password_len,
+				(u8 *) client->shared_secret,
+				client->shared_secret_len,
+				buf, sizeof(buf));
+			os_free(tmp.password);
+
+			if (res < 0 || pw_len != (size_t) res ||
+			    os_memcmp(pw, buf, res) != 0) {
+				RADIUS_DEBUG("Incorrect User-Password");
+				code = RADIUS_CODE_ACCESS_REJECT;
+			}
+		}
+	}
+
+	msg = radius_msg_new(code, hdr->identifier);
+	if (msg == NULL) {
+		RADIUS_DEBUG("Failed to allocate reply message");
+		return NULL;
+	}
+
+	if (radius_msg_copy_attr(msg, request, RADIUS_ATTR_PROXY_STATE) < 0) {
+		RADIUS_DEBUG("Failed to copy Proxy-State attribute(s)");
+		radius_msg_free(msg);
+		return NULL;
+	}
+
+	if (code == RADIUS_CODE_ACCESS_ACCEPT) {
+		struct hostapd_radius_attr *attr;
+		for (attr = sess->accept_attr; attr; attr = attr->next) {
+			if (!radius_msg_add_attr(msg, attr->type,
+						 wpabuf_head(attr->val),
+						 wpabuf_len(attr->val))) {
+				wpa_printf(MSG_ERROR, "Could not add RADIUS attribute");
+				radius_msg_free(msg);
+				return NULL;
+			}
+		}
+	}
+
+	if (radius_msg_finish_srv(msg, (u8 *) client->shared_secret,
+				  client->shared_secret_len,
+				  hdr->authenticator) < 0) {
+		RADIUS_DEBUG("Failed to add Message-Authenticator attribute");
+	}
+
+	return msg;
+}
+
+
 static int radius_server_reject(struct radius_server_data *data,
 				struct radius_client *client,
 				struct radius_msg *request,
@@ -958,6 +1041,12 @@ static int radius_server_request(struct radius_server_data *data,
 	}
 		      
 	eap = radius_msg_get_eap(msg);
+	if (eap == NULL && sess->macacl) {
+		reply = radius_server_macacl(data, client, sess, msg);
+		if (reply == NULL)
+			return -1;
+		goto send_reply;
+	}
 	if (eap == NULL) {
 		RADIUS_DEBUG("No EAP-Message in RADIUS packet from %s",
 			     from_addr);
@@ -1015,6 +1104,7 @@ static int radius_server_request(struct radius_server_data *data,
 
 	reply = radius_server_encapsulate_eap(data, client, sess, msg);
 
+send_reply:
 	if (reply) {
 		struct wpabuf *buf;
 		struct radius_hdr *hdr;
@@ -1904,6 +1994,7 @@ static int radius_server_get_eap_user(void *ctx, const u8 *identity,
 	if (ret == 0 && user) {
 		sess->accept_attr = user->accept_attr;
 		sess->remediation = user->remediation;
+		sess->macacl = user->macacl;
 	}
 	return ret;
 }