From d539b335e8a7a87dda3da259958bb52183fb760e Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Tue, 5 Mar 2019 02:29:41 +0100
Subject: conf: validate tunnel name

---
 conf/name.go   | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 conf/parser.go |  3 +++
 conf/store.go  | 18 +++++++++++++++++-
 3 files changed, 69 insertions(+), 1 deletion(-)
 create mode 100644 conf/name.go

(limited to 'conf')

diff --git a/conf/name.go b/conf/name.go
new file mode 100644
index 00000000..da9928e0
--- /dev/null
+++ b/conf/name.go
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package conf
+
+import (
+	"regexp"
+	"strings"
+)
+
+var reservedNames = []string{
+	"CON", "PRN", "AUX", "NUL",
+	"COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9",
+	"LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
+}
+
+const specialChars = "/\\<>:\"|?*\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x00"
+
+var allowedNameFormat *regexp.Regexp
+
+func init() {
+	allowedNameFormat = regexp.MustCompile("^[a-zA-Z0-9_=+.-]{1,32}$")
+}
+
+func isReserved(name string) bool {
+	if len(name) == 0 {
+		return false
+	}
+	for _, reserved := range reservedNames {
+		if strings.EqualFold(name, reserved) {
+			return true
+		}
+	}
+	return false
+}
+
+func hasSpecialChars(name string) bool {
+	return strings.ContainsAny(name, specialChars)
+}
+
+func TunnelNameIsValid(name string) bool {
+	// Aside from our own restrictions, let's impose the Windows restrictions first
+	if isReserved(name) || hasSpecialChars(name) {
+		return false
+	}
+	return allowedNameFormat.MatchString(name)
+}
diff --git a/conf/parser.go b/conf/parser.go
index 3b2ae1b3..b9ceb20e 100644
--- a/conf/parser.go
+++ b/conf/parser.go
@@ -189,6 +189,9 @@ func (c *Config) maybeAddPeer(p *Peer) {
 }
 
 func FromWgQuick(s string, name string) (*Config, error) {
+	if !TunnelNameIsValid(name) {
+		return nil, &ParseError{"Tunnel name is not valid", name}
+	}
 	lines := strings.Split(s, "\n")
 	parserState := notInASection
 	conf := Config{Name: name}
diff --git a/conf/store.go b/conf/store.go
index 7c110865..da144a17 100644
--- a/conf/store.go
+++ b/conf/store.go
@@ -36,7 +36,11 @@ func ListConfigNames() ([]string, error) {
 		if !file.Mode().IsRegular() || file.Mode().Perm()&0444 == 0 {
 			continue
 		}
-		configs[i] = strings.TrimSuffix(name, configFileSuffix)
+		name = strings.TrimSuffix(name, configFileSuffix)
+		if !TunnelNameIsValid(name) {
+			continue
+		}
+		configs[i] = name
 		i++
 	}
 	return configs[:i], nil
@@ -152,10 +156,16 @@ func NameFromPath(path string) (string, error) {
 	} else {
 		name = strings.TrimSuffix(name, configFileUnencryptedSuffix)
 	}
+	if !TunnelNameIsValid(name) {
+		return "", errors.New("Tunnel name is not valid")
+	}
 	return name, nil
 }
 
 func (config *Config) Save() error {
+	if !TunnelNameIsValid(config.Name) {
+		return errors.New("Tunnel name is not valid")
+	}
 	configFileDir, err := resolveConfigFileDir()
 	if err != nil {
 		return err
@@ -179,6 +189,9 @@ func (config *Config) Save() error {
 }
 
 func (config *Config) Path() (string, error) {
+	if !TunnelNameIsValid(config.Name) {
+		return "", errors.New("Tunnel name is not valid")
+	}
 	configFileDir, err := resolveConfigFileDir()
 	if err != nil {
 		return "", err
@@ -187,6 +200,9 @@ func (config *Config) Path() (string, error) {
 }
 
 func DeleteName(name string) error {
+	if !TunnelNameIsValid(name) {
+		return errors.New("Tunnel name is not valid")
+	}
 	configFileDir, err := resolveConfigFileDir()
 	if err != nil {
 		return err
-- 
cgit v1.2.3-59-g8ed1b