1 files changed, 75 insertions, 0 deletions
diff --git a/wgcfg/writer.go b/wgcfg/writer.go
new file mode 100644
index 0000000..aafb2a7
--- /dev/null
+++ b/wgcfg/writer.go
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package wgcfg
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"strings"
+)
+
+func (conf *Config) ToUAPI() (string, error) {
+	output := new(strings.Builder)
+	fmt.Fprintf(output, "private_key=%s\n", conf.PrivateKey.HexString())
+
+	if conf.ListenPort > 0 {
+		fmt.Fprintf(output, "listen_port=%d\n", conf.ListenPort)
+	}
+
+	output.WriteString("replace_peers=true\n")
+
+	for _, peer := range conf.Peers {
+		fmt.Fprintf(output, "public_key=%s\n", peer.PublicKey.HexString())
+		fmt.Fprintf(output, "protocol_version=1\n")
+		fmt.Fprintf(output, "replace_allowed_ips=true\n")
+
+		if !peer.PresharedKey.IsZero() {
+			fmt.Fprintf(output, "preshared_key = %s\n", peer.PresharedKey.String())
+		}
+
+		if len(peer.AllowedIPs) > 0 {
+			for _, address := range peer.AllowedIPs {
+				fmt.Fprintf(output, "allowed_ip=%s\n", address.String())
+			}
+		}
+
+		if len(peer.Endpoints) > 0 {
+			var reps []string
+			for _, ep := range peer.Endpoints {
+				ips, err := net.LookupIP(ep.Host)
+				if err != nil {
+					return "", err
+				}
+				var ip net.IP
+				for _, iterip := range ips {
+					iterip = iterip.To4()
+					if iterip != nil {
+						ip = iterip
+						break
+					}
+					if ip == nil {
+						ip = iterip
+					}
+				}
+				if ip == nil {
+					return "", errors.New("Unable to resolve IP address of endpoint")
+				}
+				resolvedEndpoint := Endpoint{ip.String(), ep.Port}
+				reps = append(reps, resolvedEndpoint.String())
+			}
+			fmt.Fprintf(output, "endpoint=%s\n", strings.Join(reps, ","))
+		} else {
+			fmt.Fprint(output, "endpoint=\n")
+		}
+
+		// Note: this needs to come *after* endpoint definitions,
+		// because setting it will trigger a handshake to all
+		// already-defined endpoints.
+		fmt.Fprintf(output, "persistent_keepalive_interval=%d\n", peer.PersistentKeepalive)
+	}
+	return output.String(), nil
+}