feat: add ssh-harden
This commit is contained in:
Executable
+292
@@ -0,0 +1,292 @@
|
||||
#!/bin/bash
|
||||
# 验证已有公钥后关闭 SSH 密码和 root 登录，并改用 55522 端口
|
||||
|
||||
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
|
||||
# shellcheck disable=SC1091
|
||||
source "$SCRIPT_DIR/common/help.sh"
|
||||
# shellcheck disable=SC1091
|
||||
source "$SCRIPT_DIR/common/os-arch.sh"
|
||||
|
||||
set -euo pipefail
|
||||
|
||||
usage() {
|
||||
cat <<'EOF'
|
||||
用法: sudo ssh-key-only [--user <用户名>] [--yes]
|
||||
|
||||
在确认目标用户已有 SSH 公钥后，写入 /etc/ssh/sshd_config.d/99-dotfile-key-only.conf：
|
||||
PubkeyAuthentication yes
|
||||
PasswordAuthentication no
|
||||
KbdInteractiveAuthentication no
|
||||
ChallengeResponseAuthentication no
|
||||
PermitRootLogin no
|
||||
Port 55522
|
||||
|
||||
选项:
|
||||
-u, --user <用户名> 要确认公钥的用户；默认使用调用 sudo 前的用户
|
||||
-y, --yes 跳过交互确认
|
||||
-h, --help 显示此帮助
|
||||
|
||||
示例:
|
||||
sudo ssh-key-only
|
||||
sudo ssh-key-only --user deploy
|
||||
|
||||
重要说明:
|
||||
- 仅支持使用 systemd 管理 SSH 服务的 Linux 服务器。
|
||||
- 脚本不会创建 SSH 密钥；目标用户的 ~/.ssh/authorized_keys 中必须已有有效公钥。
|
||||
- 写入前会校验 sshd 配置，且重载后会再次核对生效设置；失败会恢复原文件。
|
||||
- 若 UFW 已启用，脚本会自动放行 TCP 55522；云安全组和其他防火墙仍需自行放行。
|
||||
- 请保持当前 SSH 会话不要退出，另开一个终端验证密钥登录成功后再关闭。
|
||||
EOF
|
||||
}
|
||||
|
||||
TARGET_USER="${SUDO_USER:-}"
|
||||
ASSUME_YES=0
|
||||
SSH_PORT=55522
|
||||
UFW_RULE_ADDED=0
|
||||
|
||||
while [[ $# -gt 0 ]]; do
|
||||
case "$1" in
|
||||
-h|--help)
|
||||
dotfile_show_help
|
||||
;;
|
||||
-u|--user)
|
||||
[[ $# -ge 2 ]] || { echo "错误: $1 需要用户名" >&2; exit 1; }
|
||||
TARGET_USER="$2"
|
||||
shift 2
|
||||
;;
|
||||
-y|--yes)
|
||||
ASSUME_YES=1
|
||||
shift
|
||||
;;
|
||||
*)
|
||||
echo "错误: 不支持参数: $1" >&2
|
||||
usage >&2
|
||||
exit 1
|
||||
;;
|
||||
esac
|
||||
done
|
||||
|
||||
die() {
|
||||
echo "错误: $*" >&2
|
||||
exit 1
|
||||
}
|
||||
|
||||
find_sshd() {
|
||||
local candidate
|
||||
if command -v sshd >/dev/null 2>&1; then
|
||||
command -v sshd
|
||||
return
|
||||
fi
|
||||
|
||||
for candidate in /usr/sbin/sshd /usr/local/sbin/sshd; do
|
||||
[[ -x "$candidate" ]] && { printf '%s\n' "$candidate"; return; }
|
||||
done
|
||||
}
|
||||
|
||||
user_home() {
|
||||
local user="$1" home
|
||||
if command -v getent >/dev/null 2>&1; then
|
||||
home=$(getent passwd "$user" | awk -F: 'NR == 1 {print $6}')
|
||||
fi
|
||||
printf '%s' "${home:-}"
|
||||
}
|
||||
|
||||
setting_value() {
|
||||
local setting="$1"
|
||||
printf '%s\n' "$EFFECTIVE_CONFIG" | awk -v key="$setting" '$1 == key {print $2; exit}'
|
||||
}
|
||||
|
||||
check_ssh_path_permissions() {
|
||||
local path="$1" owner mode
|
||||
owner=$(stat -c '%U' "$path")
|
||||
mode=$(stat -c '%a' "$path")
|
||||
|
||||
[[ "$owner" == "$TARGET_USER" || "$owner" == "root" ]] || die "$path 的属主为 $owner，应为 $TARGET_USER 或 root"
|
||||
(( (8#$mode & 022) == 0 )) || die "$path 对组或其他用户可写（权限: $mode），sshd 可能会忽略其中的公钥"
|
||||
}
|
||||
|
||||
config_is_hardened() {
|
||||
local ports
|
||||
EFFECTIVE_CONFIG=$("$SSHD_BIN" -T -f "$SSHD_CONFIG" 2>/dev/null || true)
|
||||
[[ "$(setting_value pubkeyauthentication)" == "yes" ]] || return 1
|
||||
[[ "$(setting_value passwordauthentication)" == "no" ]] || return 1
|
||||
[[ "$(setting_value kbdinteractiveauthentication)" == "no" ]] || return 1
|
||||
[[ "$(setting_value permitrootlogin)" == "no" ]] || return 1
|
||||
ports=$(printf '%s\n' "$EFFECTIVE_CONFIG" | awk '$1 == "port" {print $2}')
|
||||
[[ "$ports" == "$SSH_PORT" ]] || return 1
|
||||
}
|
||||
|
||||
port_is_in_use() {
|
||||
if command -v ss >/dev/null 2>&1; then
|
||||
ss -H -ltn "sport = :$SSH_PORT" 2>/dev/null | grep -q .
|
||||
return
|
||||
fi
|
||||
if command -v netstat >/dev/null 2>&1; then
|
||||
netstat -ltn 2>/dev/null | grep -Eq "[.:]${SSH_PORT}[[:space:]]"
|
||||
return
|
||||
fi
|
||||
return 1
|
||||
}
|
||||
|
||||
sshd_already_uses_port() {
|
||||
local current_config
|
||||
current_config=$("$SSHD_BIN" -T -f "$SSHD_CONFIG" 2>/dev/null || true)
|
||||
printf '%s\n' "$current_config" | awk -v port="$SSH_PORT" '$1 == "port" && $2 == port {found = 1} END {exit !found}'
|
||||
}
|
||||
|
||||
ensure_ufw_port() {
|
||||
local status
|
||||
command -v ufw >/dev/null 2>&1 || return
|
||||
|
||||
status=$(ufw status 2>&1)
|
||||
if ! printf '%s\n' "$status" | grep -qi '^Status: active'; then
|
||||
echo "UFW 未启用，跳过防火墙规则修改。"
|
||||
return
|
||||
fi
|
||||
|
||||
if printf '%s\n' "$status" | grep -Eq "^[[:space:]]*${SSH_PORT}(/tcp)?[[:space:]]"; then
|
||||
echo "UFW 已有 TCP $SSH_PORT 规则，跳过。"
|
||||
return
|
||||
fi
|
||||
|
||||
if ! ufw allow "$SSH_PORT/tcp"; then
|
||||
echo "无法通过 UFW 放行 TCP $SSH_PORT。" >&2
|
||||
return 1
|
||||
fi
|
||||
UFW_RULE_ADDED=1
|
||||
echo "已通过 UFW 放行 TCP $SSH_PORT。"
|
||||
}
|
||||
|
||||
rollback_ufw_port() {
|
||||
if [[ $UFW_RULE_ADDED -eq 1 ]]; then
|
||||
if ufw --force delete allow "$SSH_PORT/tcp" >/dev/null 2>&1; then
|
||||
echo "已删除本次新增的 UFW TCP $SSH_PORT 规则。" >&2
|
||||
else
|
||||
echo "警告: 未能自动删除本次新增的 UFW TCP $SSH_PORT 规则，请手动检查。" >&2
|
||||
fi
|
||||
fi
|
||||
}
|
||||
|
||||
reload_sshd() {
|
||||
local unit
|
||||
for unit in ssh sshd; do
|
||||
if systemctl reload "$unit" >/dev/null 2>&1; then
|
||||
return 0
|
||||
fi
|
||||
done
|
||||
return 1
|
||||
}
|
||||
|
||||
if [[ $EUID -ne 0 ]]; then
|
||||
die "请使用 sudo 运行，例如: sudo $0${TARGET_USER:+ --user "$TARGET_USER"}"
|
||||
fi
|
||||
|
||||
[[ "$(get_os)" == "linux" ]] || die "当前仅支持 systemd 管理 SSH 服务的 Linux 服务器"
|
||||
command -v systemctl >/dev/null 2>&1 || die "未找到 systemctl，无法安全重载 SSH 服务"
|
||||
[[ -n "$TARGET_USER" ]] || die "无法识别目标用户；请指定 --user <用户名>"
|
||||
id "$TARGET_USER" >/dev/null 2>&1 || die "用户不存在: $TARGET_USER"
|
||||
|
||||
TARGET_HOME=$(user_home "$TARGET_USER")
|
||||
[[ -n "$TARGET_HOME" && -d "$TARGET_HOME" ]] || die "无法确定用户主目录: $TARGET_USER"
|
||||
AUTHORIZED_KEYS="$TARGET_HOME/.ssh/authorized_keys"
|
||||
[[ -r "$AUTHORIZED_KEYS" ]] || die "未找到可读取的公钥文件: $AUTHORIZED_KEYS"
|
||||
[[ -d "$TARGET_HOME/.ssh" ]] || die "未找到 SSH 配置目录: $TARGET_HOME/.ssh"
|
||||
check_ssh_path_permissions "$TARGET_HOME"
|
||||
check_ssh_path_permissions "$TARGET_HOME/.ssh"
|
||||
check_ssh_path_permissions "$AUTHORIZED_KEYS"
|
||||
|
||||
if ! grep -Eq '^[[:space:]]*(ssh-(rsa|ed25519|dss)|ecdsa-sha2-nistp(256|384|521)|sk-ssh-ed25519@openssh\.com|sk-ecdsa-sha2-nistp256@openssh\.com|[[:alnum:]_-]+-cert-v01@openssh\.com)[[:space:]]+' "$AUTHORIZED_KEYS"; then
|
||||
die "$AUTHORIZED_KEYS 中未发现有效的 SSH 公钥，已取消以避免锁定访问"
|
||||
fi
|
||||
|
||||
SSHD_BIN=$(find_sshd)
|
||||
[[ -n "$SSHD_BIN" ]] || die "未找到 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"
|
||||
fi
|
||||
|
||||
echo "将为 SSH 启用公钥认证，关闭密码、交互式认证和 root 登录，并改用端口 $SSH_PORT。"
|
||||
echo "已确认 $TARGET_USER 的公钥文件: $AUTHORIZED_KEYS"
|
||||
echo "配置文件: $DROP_IN"
|
||||
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
|
||||
read -r -p "确认云安全组已放行 TCP $SSH_PORT 并继续？[y/N] " answer
|
||||
[[ "$answer" =~ ^[Yy]$ ]] || { echo "已取消，未修改配置。"; exit 0; }
|
||||
fi
|
||||
|
||||
STAMP=$(date +%Y%m%d%H%M%S)
|
||||
BACKUP=""
|
||||
if [[ -f "$DROP_IN" ]]; then
|
||||
BACKUP="${DROP_IN}.bak.${STAMP}"
|
||||
cp -p "$DROP_IN" "$BACKUP"
|
||||
fi
|
||||
|
||||
TMP_FILE=$(mktemp "${DROP_IN}.tmp.XXXXXX")
|
||||
VALIDATION_ERROR=$(mktemp)
|
||||
trap 'rm -f "$TMP_FILE" "$VALIDATION_ERROR"' EXIT
|
||||
|
||||
cat >"$TMP_FILE" <<'EOF'
|
||||
# Managed by ~/.dotfile/script/ssh-key-only.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"
|
||||
|
||||
restore_drop_in() {
|
||||
if [[ -n "$BACKUP" ]]; then
|
||||
cp -p "$BACKUP" "$DROP_IN"
|
||||
else
|
||||
rm -f "$DROP_IN"
|
||||
fi
|
||||
}
|
||||
|
||||
if ! ensure_ufw_port; then
|
||||
restore_drop_in
|
||||
die "UFW 规则添加失败，已恢复原 SSH 配置"
|
||||
fi
|
||||
|
||||
if ! "$SSHD_BIN" -t -f "$SSHD_CONFIG" 2>"$VALIDATION_ERROR"; then
|
||||
restore_drop_in
|
||||
rollback_ufw_port
|
||||
echo "sshd 配置校验输出：" >&2
|
||||
cat "$VALIDATION_ERROR" >&2
|
||||
die "新配置未通过校验，已恢复原文件"
|
||||
fi
|
||||
|
||||
if ! config_is_hardened; then
|
||||
restore_drop_in
|
||||
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
|
||||
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
|
||||
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 "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。"
|
||||
Reference in New Issue
Block a user