From d1c6a428f5339891bfef8e7cea41bd488d591284 Mon Sep 17 00:00:00 2001
From: Stephen Seo <seo.disparate@gmail.com>
Date: Wed, 12 May 2021 20:06:36 +0900
Subject: [PATCH] Add wireguardConfigGenerator.sh

---
 wireguardConfigGenerator.sh | 138 ++++++++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100755 wireguardConfigGenerator.sh

diff --git a/wireguardConfigGenerator.sh b/wireguardConfigGenerator.sh
new file mode 100755
index 0000000..1d0411c
--- /dev/null
+++ b/wireguardConfigGenerator.sh
@@ -0,0 +1,138 @@
+#!/bin/bash
+
+set -e
+
+function print_help {
+    echo "Generates config for wireguard"
+    echo "-h - prints this help"
+    echo "-n <name> - gives a name to the config"
+    echo "-c <count> - number of clients to generate for"
+    echo "-i <ipv4_third> - sets the third byte of the ipv4"
+    echo "-e <endpoint> - ip address or domain name (required)"
+    echo "-p <port> - listen port of server (defaults to 50000)"
+    echo "-k - enables persistent keepalive for clients"
+    echo "-o <directory> - output dir to place configs (required)"
+}
+
+WGNAME="wg$(date | sha1sum | head -c 8)"
+CLIENT_COUNT=1
+IPV4_FIRST=10
+IPV4_SECOND=8
+IPV4_THIRD=0 # this can be modified with "-i <integer>"
+# IPV4_FOURTH is generated automatically. Server starts with 1, and clients increment afterward.
+SERVER_ENDPOINT="REQUIRED"
+SERVER_LISTEN_PORT=50000
+ENABLE_PERSISTENT_KEEPALIVE=0
+CONFIG_OUTPUT_DIRECTORY="REQUIRED"
+
+# OPTARG
+while getopts 'hn:c:i:e:p:ko:' opt; do
+    if [ "$opt" == "?" ]; then
+        print_help
+        exit 1
+    elif [ "$opt" == "h" ]; then
+        print_help
+        exit 0
+    elif [ "$opt" == "n" ]; then
+        WGNAME="$OPTARG"
+    elif [ "$opt" == "c" ]; then
+        CLIENT_COUNT="$OPTARG"
+    elif [ "$opt" == "i" ]; then
+        IPV4_THIRD="$OPTARG"
+    elif [ "$opt" == "e" ]; then
+        SERVER_ENDPOINT="$OPTARG"
+    elif [ "$opt" == "p" ]; then
+        SERVER_LISTEN_PORT="$OPTARG"
+        if [[ ! "${SERVER_LISTEN_PORT}" =~ [0-9]+ ]]; then
+            echo "ERROR: Given port is not a number"
+            exit 5
+        elif (($SERVER_LISTEN_PORT > 65536)); then
+            echo "ERROR: Given port is too large"
+            exit 6
+        fi
+    elif [ "$opt" == "k" ]; then
+        ENABLE_PERSISTENT_KEEPALIVE=1
+    elif [ "$opt" == "o" ]; then
+        CONFIG_OUTPUT_DIRECTORY="$OPTARG"
+    fi
+done
+
+if [ "$SERVER_ENDPOINT" == "REQUIRED" ]; then
+    echo "ERROR: Endpoint is not set with \"-e\" !"
+    exit 2
+elif [ "$CONFIG_OUTPUT_DIRECTORY" == "REQUIRED" ]; then
+    echo "ERROR: Output directory is not set with \"-o\" !"
+    exit 3
+elif [ ! -d "$CONFIG_OUTPUT_DIRECTORY" ]; then
+    echo "ERROR: dir set with \"-o\" is not a directory!"
+    exit 4
+fi
+
+echo "Creating config with name \"$WGNAME\" with \"$CLIENT_COUNT\" clients..."
+
+mkdir -p "$HOME/temp"
+
+TEMP_DIR=$(mktemp -d -p "$HOME/temp")
+
+# first create server config
+SERVER_CONF="${TEMP_DIR}/${WGNAME}server.conf"
+SERVER_PRK="$(wg genkey)"
+SERVER_PUB="$(echo -n ${SERVER_PRK} | wg pubkey)"
+
+echo "Creating server conf (will be appended to with client info)..."
+cat >> "${SERVER_CONF}" <<EOF
+[Interface]
+Address = ${IPV4_FIRST}.${IPV4_SECOND}.${IPV4_THIRD}.1/24
+ListenPort = ${SERVER_LISTEN_PORT}
+PrivateKey = ${SERVER_PRK}
+EOF
+
+# generate config per each client
+for ((i = 0; i < $CLIENT_COUNT; ++i)); do
+    CLIENT_CONF="${TEMP_DIR}/${WGNAME}client${i}.conf"
+    CLIENT_PRK="$(wg genkey)"
+    CLIENT_PUB="$(echo -n ${CLIENT_PRK} | wg pubkey)"
+    CLIENT_PRE="$(wg genpsk)"
+
+    echo "Appending client $((i + 1)) to server conf..."
+    cat >> "${SERVER_CONF}" <<EOF
+
+[Peer]
+PublicKey = ${CLIENT_PUB}
+PresharedKey = ${CLIENT_PRE}
+AllowedIPs = ${IPV4_FIRST}.${IPV4_SECOND}.${IPV4_THIRD}.$((i + 2))/32
+EOF
+
+    echo "Creating client $((i + 1)) conf..."
+    cat >> "${CLIENT_CONF}" <<EOF
+[Interface]
+Address = ${IPV4_FIRST}.${IPV4_SECOND}.${IPV4_THIRD}.$((i + 2))/24
+PrivateKey = ${CLIENT_PRK}
+
+[Peer]
+PublicKey = ${SERVER_PUB}
+PresharedKey = ${CLIENT_PRE}
+AllowedIPs = ${IPV4_FIRST}.${IPV4_SECOND}.${IPV4_THIRD}.1/32
+Endpoint = ${SERVER_ENDPOINT}:${SERVER_LISTEN_PORT}
+EOF
+
+    if (($ENABLE_PERSISTENT_KEEPALIVE)); then
+        cat >> "${CLIENT_CONF}" <<EOF
+PersistentKeepAlive = 25
+EOF
+    fi
+
+done
+
+# output configs to output directory
+echo "Placing generated configs to output directory..."
+
+cp -v "$SERVER_CONF" "${CONFIG_OUTPUT_DIRECTORY}/"
+for ((i = 0; i < $CLIENT_COUNT; ++i)); do
+    cp -v "${TEMP_DIR}/${WGNAME}client${i}.conf" "${CONFIG_OUTPUT_DIRECTORY}/"
+done
+
+echo "Removing temporary directory..."
+rm -rvf "$TEMP_DIR"
+
+echo "Done. Configs should exist at \"$CONFIG_OUTPUT_DIRECTORY\" ."