From c974d858beece2196f1c32d7abe923aa2104315c Mon Sep 17 00:00:00 2001 From: laily Date: Sat, 25 Jul 2026 21:49:20 +0800 Subject: [PATCH] feat: add ssh-harden --- script/ssh-harden.sh | 106 ++++++++++++++++++++++++++++++------------- 1 file changed, 74 insertions(+), 32 deletions(-) diff --git a/script/ssh-harden.sh b/script/ssh-harden.sh index 6446a4d..59f6354 100755 --- a/script/ssh-harden.sh +++ b/script/ssh-harden.sh @@ -13,11 +13,10 @@ usage() { cat <<'EOF' 用法: sudo ssh-harden [--user <用户名>] [--skip-key-check] [--yes] -默认在确认目标用户已有 SSH 公钥后，写入 /etc/ssh/sshd_config.d/99-dotfile-key-only.conf： +默认在确认目标用户已有 SSH 公钥后，直接更新 /etc/ssh/sshd_config 的全局配置： PubkeyAuthentication yes PasswordAuthentication no KbdInteractiveAuthentication no - ChallengeResponseAuthentication no PermitRootLogin no Port 55522 @@ -37,7 +36,7 @@ usage() { - 脚本不会创建 SSH 密钥；目标用户的 ~/.ssh/authorized_keys 中必须已有有效公钥。 - 使用 -k/--skip-key-check 时，必须已有其他已验证的登录方式（例如 Tailscale SSH 或云控制台）；该选项仅跳过本地 authorized_keys 检查。 - - 写入前会校验 sshd 配置，且重载后会再次核对生效设置；失败会恢复原文件。 + - 写入前会备份并校验 sshd_config，且重载后会再次核对生效设置；失败会恢复原文件。 - 若 UFW 已启用，脚本会自动放行 TCP 55522；云安全组和其他防火墙仍需自行放行。 - 请保持当前 SSH 会话不要退出，另开一个终端验证密钥登录成功后再关闭。 EOF @@ -190,6 +189,55 @@ reload_sshd() { return 1 } +write_hardened_config() { + awk -v port="$SSH_PORT" ' + function emit_missing() { + if (!seen["pubkeyauthentication"]) print "PubkeyAuthentication yes" + if (!seen["passwordauthentication"]) print "PasswordAuthentication no" + if (!seen["kbdinteractiveauthentication"]) print "KbdInteractiveAuthentication no" + if (!seen["permitrootlogin"]) print "PermitRootLogin no" + if (!seen["port"]) print "Port " port + } + + BEGIN { in_global = 1 } + + { + lower = tolower($0) + if (in_global && lower ~ /^[[:space:]]*match([[:space:]]|$)/) { + emit_missing() + in_global = 0 + } + + if (in_global && lower ~ /^[[:space:]]*pubkeyauthentication[[:space:]]+/) { + if (!seen["pubkeyauthentication"]++) print "PubkeyAuthentication yes" + next + } + if (in_global && lower ~ /^[[:space:]]*passwordauthentication[[:space:]]+/) { + if (!seen["passwordauthentication"]++) print "PasswordAuthentication no" + next + } + if (in_global && lower ~ /^[[:space:]]*kbdinteractiveauthentication[[:space:]]+/) { + if (!seen["kbdinteractiveauthentication"]++) print "KbdInteractiveAuthentication no" + next + } + if (in_global && lower ~ /^[[:space:]]*permitrootlogin[[:space:]]+/) { + if (!seen["permitrootlogin"]++) print "PermitRootLogin no" + next + } + if (in_global && lower ~ /^[[:space:]]*port[[:space:]]+/) { + if (!seen["port"]++) print "Port " port + next + } + + print + } + + END { + if (in_global) emit_missing() + } + ' "$SSHD_CONFIG" >"$TMP_FILE" +} + if [[ $EUID -ne 0 ]]; then die "请使用 sudo 运行，例如: sudo $0${TARGET_USER:+ --user "$TARGET_USER"}" fi @@ -219,13 +267,8 @@ SSHD_BIN=$(find_sshd) SSHD_CONFIG=/etc/ssh/sshd_config [[ -r "$SSHD_CONFIG" ]] || die "无法读取 $SSHD_CONFIG" -if ! grep -Eq '^[[:space:]]*Include[[:space:]].*sshd_config\.d' "$SSHD_CONFIG"; then - die "$SSHD_CONFIG 未包含 sshd_config.d；为避免覆盖现有规则，未作修改" -fi - DROP_IN_DIR=/etc/ssh/sshd_config.d DROP_IN="$DROP_IN_DIR/99-dotfile-key-only.conf" -mkdir -p "$DROP_IN_DIR" if ! sshd_already_uses_port && port_is_in_use; then die "TCP $SSH_PORT 已被其他服务监听；请选择空闲端口后再修改脚本" @@ -238,7 +281,7 @@ if [[ $SKIP_KEY_CHECK -eq 1 ]]; then else echo "已确认 $TARGET_USER 的公钥文件: $AUTHORIZED_KEYS" fi -echo "配置文件: $DROP_IN" +echo "配置文件: $SSHD_CONFIG" echo "若 UFW 已启用，脚本会自动放行 TCP $SSH_PORT；请确认云安全组已放行。" if [[ $ASSUME_YES -ne 1 ]]; then if [[ $SKIP_KEY_CHECK -eq 1 ]]; then @@ -250,42 +293,40 @@ if [[ $ASSUME_YES -ne 1 ]]; then fi STAMP=$(date +%Y%m%d%H%M%S) -BACKUP="" +CONFIG_BACKUP="${SSHD_CONFIG}.bak.${STAMP}" +DROP_IN_BACKUP="" +cp -p "$SSHD_CONFIG" "$CONFIG_BACKUP" + if [[ -f "$DROP_IN" ]]; then - BACKUP="${DROP_IN}.bak.${STAMP}" - cp -p "$DROP_IN" "$BACKUP" + DROP_IN_BACKUP="/etc/ssh/sshd_config.bak.${STAMP}.dotfile-key-only.conf" + cp -p "$DROP_IN" "$DROP_IN_BACKUP" + rm -f "$DROP_IN" fi -TMP_FILE=$(mktemp "${DROP_IN}.tmp.XXXXXX") +TMP_FILE=$(mktemp "${SSHD_CONFIG}.tmp.XXXXXX") VALIDATION_ERROR=$(mktemp) trap 'rm -f "$TMP_FILE" "$VALIDATION_ERROR"' EXIT -cat >"$TMP_FILE" <<'EOF' -# Managed by ~/.dotfile/script/ssh-harden.sh -PubkeyAuthentication yes -PasswordAuthentication no -KbdInteractiveAuthentication no -ChallengeResponseAuthentication no -PermitRootLogin no -Port 55522 -EOF -install -m 0600 -o root -g root "$TMP_FILE" "$DROP_IN" +write_hardened_config +install -m "$(stat -c '%a' "$SSHD_CONFIG")" -o "$(stat -c '%u' "$SSHD_CONFIG")" -g "$(stat -c '%g' "$SSHD_CONFIG")" "$TMP_FILE" "$SSHD_CONFIG" -restore_drop_in() { - if [[ -n "$BACKUP" ]]; then - cp -p "$BACKUP" "$DROP_IN" +restore_config() { + cp -p "$CONFIG_BACKUP" "$SSHD_CONFIG" + if [[ -n "$DROP_IN_BACKUP" ]]; then + mkdir -p "$DROP_IN_DIR" + cp -p "$DROP_IN_BACKUP" "$DROP_IN" else rm -f "$DROP_IN" fi } if ! ensure_ufw_port; then - restore_drop_in + restore_config die "UFW 规则添加失败，已恢复原 SSH 配置" fi if ! "$SSHD_BIN" -t -f "$SSHD_CONFIG" 2>"$VALIDATION_ERROR"; then - restore_drop_in + restore_config rollback_ufw_port echo "sshd 配置校验输出：" >&2 cat "$VALIDATION_ERROR" >&2 @@ -293,24 +334,25 @@ if ! "$SSHD_BIN" -t -f "$SSHD_CONFIG" 2>"$VALIDATION_ERROR"; then fi if ! config_is_hardened; then - restore_drop_in + restore_config rollback_ufw_port die "新配置未成为 sshd 的生效设置（可能被更早的配置覆盖），已恢复原文件" fi if ! reload_sshd; then - restore_drop_in + restore_config rollback_ufw_port die "无法重载 ssh/sshd 服务，已恢复原文件；请检查 systemctl 状态" fi if ! config_is_hardened; then - restore_drop_in + restore_config reload_sshd || true rollback_ufw_port die "重载后设置未生效，已恢复原文件并尝试重载旧配置" fi echo "已启用仅公钥 SSH 登录，已禁止 root 登录，SSH 端口已改为 $SSH_PORT。" -[[ -n "$BACKUP" ]] && echo "原配置已备份到: $BACKUP" +echo "原 SSH 配置已备份到: $CONFIG_BACKUP" +[[ -n "$DROP_IN_BACKUP" ]] && echo "旧的 dotfile SSH drop-in 已备份到: $DROP_IN_BACKUP" echo "请保持当前会话，另开终端确认可通过密钥连接到端口 $SSH_PORT 后再退出。"