CTF院赛平台搭建笔记

这次我们学院要举办CTF比赛，按照老师的意思是要随便搞一下，但是喜欢折腾的我肯定不同意了（虽然我不是信安组的但就是喜欢玩这些东西，刚好早期有部署过GZCTF，我直接跟信安的同学说你们的平台我来处理。

这次部署平台的方案：一台内网CTF主机+一台公网云主机并结合easytier构建虚拟局域网并用caddy自动SSL。

系统版本如下：公网云主机：Debian GNU/Linux 11 内网CTF主机：openEuler release 25.03

基础设置（云主机和内网CTF主机）#

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$ systemctl stop firewalld &&  systemctl disable firewalld
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$ setenforce 0

部署easytier（云主机和内网CTF主机）#

下载easytier#

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$ wget https://ghfast.top/https://github.com/EasyTier/EasyTier/releases/download/v2.2.4/easytier-linux-x86_64-v2.2.4.zip

解压压缩包#

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$ unzip easytier-linux-x86_64-v2.2.4.zip
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# 如果没有unzip下载
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# dnf install -y unzip
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# apt install -y unzip

移动目录#

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$ mv easytier-linux-x86_64 /usr/bin/easytier

编写service服务#

--ipv4 10.144.144.1手动分配虚拟局域网的IP地址

--network-name XXSS虚拟局域网络名称

--network-secret XXSS001虚拟局域网的密码

PS：这里我只展示其中一台的配置文件，其实要改的就是IP地址，因为我要自己分配IP地址所以我就在配置文件里指定IP

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$ cat >> /etc/systemd/system/easytier.service << EOF
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[Unit]
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Description=EasyTier Service
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After=network.target syslog.target
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Wants=network.target
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[Service]
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Type=simple
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ExecStart=/usr/bin/easytier/easytier-core --ipv4 10.144.144.1 --network-name XXSS --network-secret XXSS001
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[Install]
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WantedBy=multi-user.target
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EOF

启动easytier服务#

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$ systemctl daemon-reload
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$ systemctl enable easytier
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$ systemctl start easytier
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$ systemctl status easytier
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● easytier.service - EasyTier Service
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     Loaded: loaded (/etc/systemd/system/easytier.service; disabled; preset: disabled)
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     Active: active (running) since Fri 2025-05-16 13:44:41 CST; 7h ago
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   Main PID: 269640 (easytier-core)
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      Tasks: 4 (limit: 98868)
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     Memory: 46.0M ()
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     CGroup: /system.slice/easytier.service
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             └─269640 /usr/bin/easytier/easytier-core --ipv4 10.144.144.2 --network-name XXSS --network>
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......

部署GZCTF平台#

配置Docker环境#

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[root@CTFGZ ~]# dnf install -y docker-client docker-engine

配置docker-compose#

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[root@CTFGZ ~]# wget https://ghfast.top/https://github.com/docker/compose/releases/download/v2.36.0/docker-compose-linux-x86_64
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[root@CTFGZ ~]# mv docker-compose-linux-x86_64 /usr/bin/docker-compose
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[root@CTFGZ ~]# chmod +x /usr/bin/docker-compose

启动docker服务#

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[root@CTFGZ ~]# systemctl enable docker
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[root@CTFGZ ~]# systemctl start docker

检查docker服务#

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[root@CTFGZ ~]# systemctl status docker
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● docker.service - Docker Application Container Engine
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     Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; preset: disabled)
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     Active: active (running) since Thu 2025-05-15 20:37:27 CST; 1 day 1h ago
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......
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[root@CTFGZ ~]# docker version
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Client:
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 Version:           18.09.0
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 EulerVersion:      18.09.0.346
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 API version:       1.39
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 Go version:        go1.21.4
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 Git commit:        270f890
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 Built:             Fri Mar 21 10:03:24 2025
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 OS/Arch:           linux/amd64
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 Experimental:      false
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Server:
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 Engine:
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  Version:          18.09.0
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  EulerVersion:     18.09.0.346
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  API version:      1.39 (minimum version 1.12)
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  Go version:       go1.21.4
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  Git commit:       270f890
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  Built:            Fri Mar 21 10:02:53 2025
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  OS/Arch:          linux/amd64
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  Experimental:     false
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[root@CTFGZ ~]# docker-compose version
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Docker Compose version v2.36.0

创建GZCTF项目#

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[root@CTFGZ ~]# mkdir /opt/GZCTF
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[root@CTFGZ ~]# cd /opt/GZCTF/

配置GZCTF容器端口范围#

因为云主机某些端口占用了，我现在需要指定比赛生成的容器端口在指定范围内。（因为我是内网主机映射到云主机上的所以要这么做）

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# 指定端口从31000到31099
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[root@CTFGZ GZCTF]# echo "net.ipv4.ip_local_port_range = 31000 31099" >> /etc/sysctl.conf
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[root@CTFGZ GZCTF]# sysctl -p

编写GZCTF配置文件#

<Your_postgres_password>数据库密码 <basexxxxx>加密信息 <Your PUBLIC_ENTRY>地址段或者域名

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[root@CTFGZ GZCTF]# vim appsettings.json
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{
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  "AllowedHosts": "*",
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  "ConnectionStrings": {
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    "Database": "Host=db:5432;Database=gzctf;Username=postgres;Password=<Your_postgres_password>",
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    "RedisCache": "cache:6379,abortConnect=false"
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  },
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  "EmailConfig": {
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    "SendMailAddress": "",
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    "UserName": "",
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    "Password": "",
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    "Smtp": {
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      "Host": "localhost",
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      "Port": 587
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    }
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  },
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  "XorKey": "<basexxxxx>",  //自行配置
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  "ContainerProvider": {
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    "Type": "Docker", // or "Kubernetes"
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    "PublicEntry": "<Your PUBLIC_ENTRY>", // or "xxx.xxx.xxx.xxx"
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    "PortMappingType": "Default",
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    "EnableTrafficCapture": false,
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    "DockerConfig": {
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      "SwarmMode": false,
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      "Uri": "unix:///var/run/docker.sock"
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    }
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  },
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  "RequestLogging": false,
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  "DisableRateLimit": true,
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  "RegistryConfig": {
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    "UserName": "",
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    "Password": "",
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    "ServerAddress": ""
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  },
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  "CaptchaConfig": {
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    "Provider": "None",
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    "SiteKey": "<Your SITE_KEY>",
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    "SecretKey": "<Your SECRET_KEY>",
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    "GoogleRecaptcha": {
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      "VerifyAPIAddress": "https://www.recaptcha.net/recaptcha/api/siteverify",
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      "RecaptchaThreshold": "0.5"
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    }
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  },
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  "ForwardedOptions": {
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    "ForwardedHeaders": 5,
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    "ForwardLimit": 1,
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    "TrustedNetworks": ["192.168.12.0/8"]
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  }
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}

配置docker compose文件#

<初始用户密码>密码需要大写字母

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[root@CTFGZ GZCTF]# vim docker-compose.yml
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services:
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  gzctf:
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    image: registry.cn-shanghai.aliyuncs.com/gztime/gzctf:latest
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    restart: always
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    environment:
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      - "LANG=zh_CN.UTF-8"
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      - "GZCTF_ADMIN_PASSWORD=<初始用户密码>"
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    ports:
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      - "80:8080"
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    volumes:
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      - "./data/files:/app/files"
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      - "./appsettings.json:/app/appsettings.json:ro"
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      - "/var/run/docker.sock:/var/run/docker.sock"
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    depends_on:
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      - db
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      - cache
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  cache:
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    # It is recommended to use garnet, you can also use ghcr.nju.edu.cn/microsoft/garnet-alpine:latest
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    image: redis:alpine
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    command: ["--bind", "0.0.0.0"]
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    restart: always
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  db:
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    image: postgres:alpine
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    restart: always
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    environment:
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      - "POSTGRES_PASSWORD=<Your_postgres_password>"  //记得修改
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    volumes:
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      - "./data/db:/var/lib/postgresql/data"

启动GZCTF#

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[root@CTFGZ GZCTF]# docker-compose up -d
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[+] Running 3/3
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 ✔ Container gzctf-cache-1   Started          0.2s
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 ✔ Container gzctf-db-1      Started          0.3s
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 ✔ Container gzctf-gzctf-1   Started          0.5s

备注#

初始用户：Admin 密码：yml文件<初始用户密码>配置的密码

如果登录Admin初始用户失败，请按下面步骤进行调整 1、在Web界面创建任意用户 2、回到命令行，给创建的用户赋予管理员权限

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[root@CTFGZ GZCTF]# docker-compose exec db psql -U postgres
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psql (17.5)
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Type "help" for help.
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postgres=# \c gzctf
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You are now connected to database "gzctf" as user "postgres".
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gzctf=# UPDATE "AspNetUsers" SET "Role"=3 WHERE "UserName"='创建新的用户名';
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UPDATE 1
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gzctf=# exit

Caddy#

现在这个步骤就是在云主机上的操作了，我云主机系统是debian <easytier_CTF_ip>这个是配置CTF内网主机上easytier的IP。

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root@host:~# curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
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root@host:~# curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | tee /etc/apt/sources.list.d/caddy-stable.list
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root@host:~# apt update
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root@host:~# apt install -y caddy
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root@host:~# vi /etc/caddy/Caddyfile
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# ----------------------
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# CTF 赛事平台
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# ----------------------
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ctf.xxx.xxx {
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        reverse_proxy <easytier_CTF_ip>:80 {
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                # 精简头部传递（Caddy 默认会传递 X-Forwarded-* 头）
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                header_up X-Real-IP {remote}
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                header_up X-Forwarded-Port {server_port}
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        }
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}

刚刚我们说到配置容器范围，现在就要用脚本配置这个端口的映射 <easytier_CTF_ip>这个IP地址要自行修改

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root@host:~# cat >> caddy.sh << EOF
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# 生成31000-31099端口配置
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echo "# 自动生成端口映射配置" >> /etc/caddy/Caddyfile
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for port in {31000..31099}; do
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  cat << EOF >> /etc/caddy/Caddyfile
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ctf.leekk.me:$port {
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    reverse_proxy <easytier_CTF_ip>:$port {
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        header_up X-Real-IP {remote}
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        header_up X-Forwarded-Port {server_port}
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    }
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}
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EOF
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done
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EOF

以下是这次部署的样图#

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graph TB
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    classDef public fill:#FFE8D4,stroke:#FF6B00;
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    classDef private fill:#D5E8D4,stroke:#4CAF50;
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    classDef tunnel stroke:#666,stroke-dasharray:5;
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    subgraph 公网环境
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        Internet[互联网]
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        客户端(客户端) -->|HTTPS请求\n443端口| 云主机B
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    end
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    subgraph 虚拟局域网
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        云主机B:::public -.->|easytier隧道\n10.144.144.0/24| 内网主机A:::private
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    end
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    云主机B -->|反向代理规则\nCaddy: ctf.xxx.com -> 10.144.144.1:80| 内网主机A
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    内网主机A -->|响应数据| 云主机B
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    云主机B -->|加密响应| 客户端
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    style 虚拟局域网 fill:#F0F5FF,stroke:#3366FF
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    linkStyle 2 stroke:#FF6B00,stroke-width:2px
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    linkStyle 3 stroke:#4CAF50
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    linkStyle 4 stroke:#FF6B00
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    class 云主机B,Internet,客户端 public
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    class 内网主机A private

基础设置（云主机 和 内网CTF主机）#

部署easytier（云主机 和 内网CTF主机）#