ssh-proxy.sh

#!/usr/bin/env bash
# ssh-proxy.sh – auto‑installer & manager for an SSH→SOCKS→HTTP proxy
# ------------------------------------------------------------------
# * Creates an SSH key, copies it to the server
# * Adds an alias to ~/.ssh/config
# * Generates a systemd‑user service (autossh + gost)
# * Provides install | reconfigure | uninstall | status commands
# * Optionally installs missing dependencies via the host package manager
# ------------------------------------------------------------------
set -euo pipefail

# ---- meta -----------------------------------------------------
SCRIPT_NAME="ssh-proxy"
AUTHOR="Arshia Moghaddam"
GITHUB_URL="https://github.com/ars2062"
VERSION="1.0.0"

# ---- paths & constants ---------------------------------------
APP_NAME="$SCRIPT_NAME"            # keep for backward compat if used elsewhere
CONFIG_DIR="$HOME/.config/$APP_NAME"
CONFIG_FILE="$CONFIG_DIR/config"
SERVICE_FILE="$HOME/.config/systemd/user/$APP_NAME.service"
SSH_KEY="$HOME/.ssh/id_ed25519_${APP_NAME}"
SSH_ALIAS="$APP_NAME"
SOCKS_PORT=10808
HTTP_PORT=9001
AUTOSSH_POLL=30

# ---- pretty printing helpers ---------------------------------
BOLD=$(tput bold || true)
GREEN=$(tput setaf 2 || true)
RED=$(tput setaf 1 || true)
YELLOW=$(tput setaf 3 || true)
RESET=$(tput sgr0 || true)
info()  { printf "%s%s%s\n" "$GREEN" "$*" "$RESET"; }
warn()  { printf "%s%s%s\n" "$YELLOW" "$*" "$RESET"; }
error() { printf "%s%s%s\n" "$RED" "$*" "$RESET" >&2; }

banner() {
  local inner_width=78
  local credit_line="$SCRIPT_NAME v$VERSION – by $AUTHOR | $GITHUB_URL"
  local credit_len=${#credit_line}
  if [[ $credit_len -gt $inner_width ]]; then
    credit_line="${credit_line:0:$inner_width}"
    credit_len=${#credit_line}
  fi
  local pad_left=$(( (inner_width - credit_len) / 2 ))
  local pad_right=$(( inner_width - credit_len - pad_left ))

  cat <<'ART'


┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃                                                                              ┃
┃                                                                              ┃
┃   ███████╗███████╗██╗  ██╗      ██████╗ ██████╗  ██████╗ ██╗  ██╗██╗   ██╗   ┃
┃   ██╔════╝██╔════╝██║  ██║      ██╔══██╗██╔══██╗██╔═══██╗╚██╗██╔╝╚██╗ ██╔╝   ┃
┃   ███████╗███████╗███████║█████╗██████╔╝██████╔╝██║   ██║ ╚███╔╝  ╚████╔╝    ┃
┃   ╚════██║╚════██║██╔══██║╚════╝██╔═══╝ ██╔══██╗██║   ██║ ██╔██╗   ╚██╔╝     ┃
┃   ███████║███████║██║  ██║      ██║     ██║  ██║╚██████╔╝██╔╝ ██╗   ██║      ┃
┃   ╚══════╝╚══════╝╚═╝  ╚═╝      ╚═╝     ╚═╝  ╚═╝ ╚═════╝ ╚═╝  ╚═╝   ╚═╝      ┃
┃                                                                              ┃
ART

  printf '┃%*s%s%*s┃\n' "$pad_left" '' "$credit_line" "$pad_right" ''

  cat <<'ART'
┃                                                                              ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
ART
}

require_cmd() { command -v "$1" >/dev/null 2>&1 || { error "Missing dependency: $1"; exit 1; }; }

# ---- dependency installer ------------------------------------
install_dependencies() {
  local need_install=()
  for cmd in autossh gost ssh ssh-keygen ssh-copy-id; do
    command -v "$cmd" >/dev/null 2>&1 || need_install+=("$cmd")
  done
  [[ ${#need_install[@]} -eq 0 ]] && return

  warn "Installing missing dependencies: ${need_install[*]}"
  if command -v apt-get >/dev/null 2>&1; then
    sudo apt-get update -qq
    if [[ " ${need_install[*]} " =~ " autossh " ]]; then sudo apt-get install -y autossh; fi
  elif command -v dnf >/dev/null 2>&1; then
    sudo dnf install -y autossh
  elif command -v pacman >/dev/null 2>&1; then
    sudo pacman -Sy --noconfirm autossh
  else
    warn "Unsupported package manager – please install autossh and gost manually."
  fi

  if ! command -v gost >/dev/null 2>&1; then
    warn "Installing gost from GitHub releases..."
    warn "Installing gost from GitHub releases..."
    local tmp
    tmp=$(mktemp -d)
    curl -sSL -o "$tmp/gost.tgz" "https://github.com/go-gost/gost/releases/latest/download/gost-linux-amd64.tgz"
    tar -C "$tmp" -xzf "$tmp/gost.tgz"
    sudo /usr/bin/install -m 755 "$tmp/gost" /usr/local/bin/gost
    rm -rf "$tmp"
  fi
}

# ---- config helpers ------------------------------------------
generate_config() {
  mkdir -p "$CONFIG_DIR"
  cat >"$CONFIG_FILE" <<EOF
REMOTE_HOST="$REMOTE_HOST"
REMOTE_USER="$REMOTE_USER"
REMOTE_PORT="$REMOTE_PORT"
SOCKS_PORT="$SOCKS_PORT"
HTTP_PORT="$HTTP_PORT"
SSH_KEY="$SSH_KEY"
SSH_ALIAS="$SSH_ALIAS"
EOF
}

load_config() {
  [[ -f $CONFIG_FILE ]] || { error "Config not found. Run '$0 install' first."; exit 1; }
  # shellcheck source=/dev/null
  source "$CONFIG_FILE"
}

generate_ssh_config_block() {
cat <<EOF
Host $SSH_ALIAS
    HostName $REMOTE_HOST
    User $REMOTE_USER
    Port $REMOTE_PORT
    IdentityFile $SSH_KEY
    ServerAliveInterval 60
    ServerAliveCountMax 3
EOF
}

# ---- core actions --------------------------------------------
install() {
  install_dependencies
  require_cmd autossh
  require_cmd gost
  require_cmd ssh
  require_cmd ssh-keygen

  [[ -f $CONFIG_FILE ]] && { warn "Existing configuration found."; reconfigure_prompt; return; }

  read -rp "Remote SSH host (IP or DNS): " REMOTE_HOST
  read -rp "Remote SSH user [$(whoami)]: " REMOTE_USER
  REMOTE_USER=${REMOTE_USER:-$(whoami)}
  read -rp "Remote SSH port [22]: " REMOTE_PORT
  REMOTE_PORT=${REMOTE_PORT:-22}

  info "Generating SSH key $SSH_KEY (if not present)…"
  [[ -f $SSH_KEY ]] || ssh-keygen -t ed25519 -f "$SSH_KEY" -N "" -C "$APP_NAME"

  info "Copying public key to $REMOTE_USER@$REMOTE_HOST…"
  ssh-copy-id -i "${SSH_KEY}.pub" -p "$REMOTE_PORT" "$REMOTE_USER@$REMOTE_HOST"

  mkdir -p "$HOME/.ssh"
  touch "$HOME/.ssh/config"
  if ! grep -q "Host $SSH_ALIAS" "$HOME/.ssh/config"; then
    generate_ssh_config_block >>"$HOME/.ssh/config"
    info "Added entry '$SSH_ALIAS' to ~/.ssh/config"
  else
    warn "An entry named '$SSH_ALIAS' already exists in ~/.ssh/config (skipped)"
  fi

  generate_config
  info "Config saved to $CONFIG_FILE"

  create_service
  info "Installation complete. Use 'systemctl --user status $APP_NAME' to see logs."
}

create_service() {
  mkdir -p "$(dirname "$SERVICE_FILE")"

  # Absolute path so systemd doesn’t need PATH to find it
  GOST_BIN=$(command -v gost)

  cat >"$SERVICE_FILE" <<EOF
[Unit]
Description=SSH → SOCKS → HTTP proxy tunnel (autossh + gost)
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
# autossh housekeeping
Environment="AUTOSSH_GATETIME=0" "AUTOSSH_POLL=$AUTOSSH_POLL"
# add /usr/local/bin in case you put other stuff there later
Environment="PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/bin"
Restart=on-failure
RestartSec=5
ExecStart=/usr/bin/env bash -c 'autossh -M 0 -N -D 127.0.0.1:$SOCKS_PORT $SSH_ALIAS & exec "$GOST_BIN" -L=http://:$HTTP_PORT -F=socks5://127.0.0.1:$SOCKS_PORT'
KillMode=control-group

[Install]
WantedBy=default.target
EOF

  systemctl --user daemon-reload
  systemctl --user enable --now "$APP_NAME.service"
}


uninstall() {
  load_config
  info "Stopping and disabling service…"
  systemctl --user disable --now "$APP_NAME.service" || true
  rm -f "$SERVICE_FILE"

  if grep -q "Host $SSH_ALIAS" "$HOME/.ssh/config"; then
    info "Removing SSH config entry '$SSH_ALIAS'…"
    sed -i.bak "/Host $SSH_ALIAS/,+5d" "$HOME/.ssh/config"
  fi

  info "Removing config directory…"
  rm -rf "$CONFIG_DIR"

  read -rp "Delete SSH key pair $SSH_KEY? [y/N]: " ans
  if [[ $ans =~ ^[Yy]$ ]]; then
    rm -f "$SSH_KEY" "$SSH_KEY.pub"
    info "Key pair deleted."
  fi

  info "Uninstall completed."
}

status() {
  load_config
  systemctl --user status "$APP_NAME.service"
}

# ---- runtime controls ---------------------------------------
stop() {
  load_config
  info "Stopping service…"
  systemctl --user stop "$APP_NAME.service"
}

start() {
  load_config
  info "Starting service…"
  systemctl --user start "$APP_NAME.service"
}


reconfigure_prompt() {
  read -rp "Reinstall? This will overwrite configuration. [y/N]: " ans
  [[ $ans =~ ^[Yy]$ ]] || { info "Aborted."; exit 0; }
  uninstall
  install
}

usage() {
  banner
  cat <<EOF
${BOLD}Usage:${RESET} $0 <command>

Commands:
  install       Install and start the proxy tunnel
  reconfigure   Run the installer again and overwrite existing config
  uninstall     Remove the service, config, and optionally the key
  status        Show service status
  start         Start the proxy service
  stop          Stop the proxy service
  help          Show this message
EOF
}

# ---- main -----------------------------------------------------
banner
case "${1:-install}" in
  install) install ;;
  reconfigure) reconfigure_prompt ;;
  uninstall) uninstall ;;
  status) status ;;
  start) start ;;
  stop) stop ;;
  help|-h|--help) usage ;;
  *) usage ;;
esac