commit 0580cf7cd8e1e670dba9e3bc660523f9c1f7abf4 · dunkirk.sh/ncae-tools

+21 -45

00-mini-hack-overview.md

···

       4
       4
        
       

     

       5
       5
        
       ```

     

       6
       6
        
       External Network (172.20.0.0/16)

     

       7
       7
       -
       ├── Kali External: 172.20.2

     

       7
       7
       +
       ├── Kali External: 172.20.0.2

     

       8
       8
        
       ├── Router External: 172.20.<team>.1

     

       9
       9
       -
       └── Scoring Server: 172.20.1

     

       9
       9
       +
       └── Scoring Server: 172.20.0.1

     

       10
       10
        
       

     

       11
       11
        
       Internal Network (192.168.<team>.0/24)

     

       12
       12
        
       ├── Router Internal: 192.168.<team>.1

     
···

       27
       27
        
       ### 1. Find Your Team Number

     

       28
       28
        
       

     

       29
       29
        
       **On Kali External**:

     

       30
       30
       -
       ```bash

     

       31
       31
       -
       ip addr show                    # Look for 172.20.X

     

       32
       32
       -
       # If you see 172.20.2, your team number is 2

     

       33
       33
       -
       # Check scoreboard at http://172.20.1 for confirmation

     

       34
       34
       -
       ```

     

       30
       30
       +
       

     

       31
       31
       +
       Check scoreboard at http://172.20.1 for team number (username: `sandbox` pass: `password`).

     

       35
       32
        
       

     

       36
       33
        
       ### 2. Configure Router

     

       37
       34
        
       

     

       38
       35
        
       **Login to MikroTik** (via ProxMox console or SSH):

     

       36
       36
       +
       

     

       39
       37
        
       ```bash

     

       40
       38
        
       # Default login

     

       41
       39
        
       admin

     
···

       46
       44
        
       ```

     

       47
       45
        
       

     

       48
       46
        
       **Assign IP addresses**:

     

       47
       47
       +
       

     

       49
       48
        
       ```bash

     

       49
       49
       +
       /interface print

     

       50
       50
       +
       

     

       50
       51
        
       # External interface

     

       51
       51
       -
       /ip address add address=172.20.<team>.1/16 interface=ether3

     

       52
       52
       +
       /ip address add address=172.20.<team>.1/16 interface=ether#

     

       52
       53
        
       

     

       53
       54
        
       # Internal interface

     

       54
       54
       -
       /ip address add address=192.168.<team>.1/24 interface=ether4

     

       55
       55
       +
       /ip address add address=192.168.<team>.1/24 interface=ether#

     

       55
       56
        
       

     

       56
       57
        
       # Verify

     

       57
       58
        
       /ip address print

     

       58
       59
        
       ```

     

       59
       60
        
       

     

       60
       60
       -
       **Or use Web GUI**: `http://172.20.<team>.1:8080`

     

       61
       61
       -
       - Login: `admin` / `<your password>`

     

       62
       62
       -
       - Go to **Quick Set**

     

       63
       63
       -
       - Enter external IP: `172.20.<team>.1/16`

     

       64
       64
       -
       - Enter internal IP: `192.168.<team>.1/24`

     

       65
       65
       -
       - ✅ **Check "Enable NAT"** (required!)

     

       66
       66
       -
       - Click **Apply Configuration**

     

       61
       61
       +
       The webgui can't be used here because there are no ip addresses assigned to it yet.

     

       67
       62
        
       

     

       68
       63
        
       ### 3. Configure Ubuntu Web Server

     

       69
       64
        
       

     

       70
       65
        
       **Assign static IP**:

     

       66
       66
       +
       

     

       71
       67
        
       ```bash

     

       72
       68
        
       sudo nano /etc/netplan/01-network-manager-all.yaml

     

       73
       69
        
       ```

     
···

       90
       86
        
       ping 192.168.<team>.1          # Test router connectivity

     

       91
       87
        
       ```

     

       92
       88
        
       

     

       89
       89
       +
       or open settings -> enable wired and config there

     

       90
       90
       +
       

     

       93
       91
        
       **Start Apache**:

     

       92
       92
       +
       

     

       94
       93
        
       ```bash

     

       95
       94
        
       sudo systemctl restart apache2

     

       96
       95
        
       sudo systemctl status apache2   # Should show "active (running)"

     

       97
       96
        
       ```

     

       98
       97
        
       

     

       99
       99
       -
       **Test locally**:

     

       100
       98
        
       ```bash

     

       101
       101
       -
       curl http://192.168.<team>.2    # Should return HTML

     

       99
       99
       +
       sudo vi /var/www/html/index.html # change team number

     

       102
       100
        
       ```

     

       103
       101
        
       

     

       104
       102
        
       ### 4. Configure Port Forwarding (Router)

     

       105
       103
        
       

     

       106
       106
       -
       **Web GUI Method** (recommended):

     

       104
       104
       +
       **Web GUI**:

     

       105
       105
       +
       

     

       107
       106
        
       ```

     

       108
       107
        
       http://172.20.<team>.1:8080

     

       109
       108
        
       ```

     

       110
       109
        
       

     

       111
       111
       -
       1. Go to **Quick Set** → **Port Mapping**

     

       110
       110
       +
       1. Go to **Quick Set** → **Port Mapping** (enable nat here and change gateway to `172.20.1.1`)

     

       112
       111
        
       2. Click **New**

     

       113
       112
        
          - Name: `www-tcp`

     

       114
       113
        
          - Protocol: `TCP`

     
···

       126
       125
        
       ### 5. Test From External Network

     

       127
       126
        
       

     

       128
       127
        
       **On Kali External**:

     

       128
       128
       +
       

     

       129
       129
        
       ```bash

     

       130
       130
        
       ping 172.20.<team>.1                    # Router should respond

     

       131
       131
        
       curl http://172.20.<team>.1             # Should show web content from internal server

     
···

       135
       135
        
       

     

       136
       136
        
       All lights should be green!

     

       137
       137
        
       

     

       138
       138
       -
       ## Quick Troubleshooting

     

       139
       139
       -
       

     

       140
       140
       -
       | Problem | Check |

     

       141
       141
       -
       |---------|-------|

     

       142
       142
       -
       | Router not pingable | Verify IP on ether3: `/ip address print` |

     

       143
       143
       -
       | Web not accessible | 1. Is Apache running? 2. Did you enable NAT? 3. Port forwarding rules exist? |

     

       144
       144
       -
       | Internal server can't reach router | Check internal IP on ether4, verify gateway in netplan |

     

       145
       145
       -
       | Lights still red | Wait 30 seconds for scoring refresh, check exact IPs match topology |

     

       146
       146
       -
       

     

       147
       138
        
       ## Configuration Files Reference

     

       148
       139
        
       

     

       149
       140
        
       **Router**: Web GUI at `http://172.20.<team>.1:8080` or CLI via console

     

       150
       141
        
       

     

       151
       142
        
       **Ubuntu Web Server**:

     

       143
       143
       +
       

     

       152
       144
        
       - Network: `/etc/netplan/01-network-manager-all.yaml`

     

       153
       145
        
       - Apache: `sudo systemctl restart apache2`

     

       154
       146
        
       - Website content: `/var/www/html/`

     

       155
       147
        
       

     

       156
       148
        
       **Kali Machines**: For testing only, no configuration needed

     

       157
       157
       -
       

     

       158
       158
       -
       ## Common Mistakes

     

       159
       159
       -
       

     

       160
       160
       -
       ❌ Forgot to enable NAT on router  

     

       161
       161
       -
       ❌ Port forwarding only has TCP rule (need UDP too)  

     

       162
       162
       -
       ❌ Wrong team number in IP addresses  

     

       163
       163
       -
       ❌ Apache not started on Ubuntu  

     

       164
       164
       -
       ❌ Netplan syntax error (YAML is whitespace-sensitive)  

     

       165
       165
       -
       ❌ Router interface names wrong (check with `interface print`)

     

       166
       166
       -
       

     

       167
       167
       -
       ## Time-Saving Tips

     

       168
       168
       -
       

     

       169
       169
       -
       1. Use **web GUI for router** - faster than CLI for NAT/port forwarding

     

       170
       170
       -
       2. Copy/paste team number once you know it - avoid typos

     

       171
       171
       -
       3. Test each step before moving on (ping, curl, status checks)

     

       172
       172
       -
       4. If stuck, verify each light's requirement on scoreboard

+72 -31

README.md

···

       1
       1
       -
       # Linux Service Configuration Writeups

     

       1
       1
       +
       # NCAE Linux Competition Tools

     

       2
       2
       +
       

     

       3
       3
       +
       > [!CAUTION]

     

       4
       4
       +
       > These writeups are tailored for NCAE cybersecurity competitions and may not reflect production best practices.

     

       5
       5
       +
       >

     

       6
       6
       +
       > Focus is on speed and competition scenarios, not enterprise deployment.

     

       2
       7
        
       

     

       3
       8
        
       Quick reference guides for configuring services in Linux competitions. Assumes basic Linux knowledge (filesystem navigation, systemctl, ssh, etc.).

     

       4
       9
        
       

     

       5
       5
       -
       ## Writeups

     

       10
       10
       +
       ## The Layout

     

       6
       11
        
       

     

       7
       7
       -
       0. **[Mini-Hack Quick Start](00-mini-hack-overview.md)** - Complete mini-hack walkthrough checklist

     

       8
       8
       -
       1. **[Services Overview](01-services-overview.md)** - General approach to any service

     

       9
       9
       -
       2. **[Apache Web Service](02-apache-web-service.md)** - HTTP/HTTPS server configuration

     

       10
       10
       -
       3. **[SSH Service](03-ssh-service.md)** - Remote access, keys, security

     

       11
       11
       -
       4. **[Network Configuration](04-network-configuration.md)** - Static IPs across different distros

     

       12
       12
       -
       5. **[DNS, Rsync, Cron](05-dns-rsync-cron.md)** - Name resolution and automated backups

     

       13
       13
       -
       6. **[UFW Firewall](06-ufw-firewall.md)** - Ubuntu firewall configuration

     

       14
       14
       -
       7. **[Active Connection Defense](07-active-connection-defense.md)** - Monitor and kill malicious connections

     

       15
       15
       -
       8. **[MikroTik Router](08-mikrotik-router.md)** - Router configuration (2025 competition)

     

       12
       12
       +
       ```bash

     

       13
       13
       +
       ~/ncae-tools

     

       14
       14
       +
       ├── 00-mini-hack-overview.md        # Complete mini-hack walkthrough checklist

     

       15
       15
       +
       ├── 01-services-overview.md         # General approach to any service

     

       16
       16
       +
       ├── 02-apache-web-service.md        # HTTP/HTTPS server configuration

     

       17
       17
       +
       ├── 03-ssh-service.md               # Remote access, keys, security

     

       18
       18
       +
       ├── 04-network-configuration.md     # Static IPs across different distros

     

       19
       19
       +
       ├── 05-dns-rsync-cron.md            # Name resolution and automated backups

     

       20
       20
       +
       ├── 06-ufw-firewall.md              # Ubuntu firewall configuration

     

       21
       21
       +
       ├── 07-active-connection-defense.md # Monitor and kill malicious connections

     

       22
       22
       +
       └── 08-mikrotik-router.md           # Router configuration (2025 minitik)

     

       23
       23
       +
       ```

     

       16
       24
        
       

     

       17
       25
        
       ## Service-Specific Quick Reference

     

       18
       26
        
       

     

       19
       27
        
       ### Apache Service Names

     

       28
       28
       +
       

     

       20
       29
        
       ```bash

     

       21
       30
        
       apache2      # Ubuntu/Debian/Kali

     

       22
       31
        
       httpd        # CentOS/RHEL

     
···

       24
       33
        
       

     

       25
       34
        
       ### Network Configuration Files

     

       26
       35
        
       

     

       27
       27
       -
       | Distribution | Config Location |

     

       28
       28
       -
       |--------------|----------------|

     

       29
       29
       -
       | Kali/Debian  | `/etc/network/interfaces` |

     

       30
       30
       -
       | Ubuntu       | `/etc/netplan/*.yaml` |

     

       36
       36
       +
       | Distribution | Config Location                          |

     

       37
       37
       +
       | ------------ | ---------------------------------------- |

     

       38
       38
       +
       | Kali/Debian  | `/etc/network/interfaces`                |

     

       39
       39
       +
       | Ubuntu       | `/etc/netplan/*.yaml`                    |

     

       31
       40
        
       | CentOS/RHEL  | `/etc/sysconfig/network-scripts/ifcfg-*` |

     

       32
       41
        
       

     

       33
       42
        
       ### SSH Key Permissions

     

       43
       43
       +
       

     

       34
       44
        
       ```bash

     

       35
       45
        
       chmod 700 ~/.ssh/

     

       36
       46
        
       chmod 600 ~/.ssh/id_rsa          # Private key

     
···

       39
       49
        
       ```

     

       40
       50
        
       

     

       41
       51
        
       Regenerate host keys on cloned VMs:

     

       52
       52
       +
       

     

       42
       53
        
       ```bash

     

       43
       54
        
       sudo ssh-keygen -A

     

       44
       55
        
       sudo systemctl restart sshd

     

       45
       56
        
       ```

     

       46
       57
        
       

     

       47
       58
        
       ### UFW Firewall

     

       59
       59
       +
       

     

       48
       60
        
       ```bash

     

       49
       61
        
       sudo ufw enable

     

       50
       62
        
       sudo ufw allow ssh

     
···

       56
       68
        
       ```

     

       57
       69
        
       

     

       58
       70
        
       ### Active Connection Monitoring

     

       71
       71
       +
       

     

       59
       72
        
       ```bash

     

       60
       73
        
       sudo netstat -tunap                     # All connections with PIDs

     

       61
       74
        
       sudo netstat -tunap | grep ESTABLISHED  # Only active

     
···

       65
       78
        
       ```

     

       66
       79
        
       

     

       67
       80
        
       ### MikroTik Router

     

       81
       81
       +
       

     

       68
       82
        
       **CLI**:

     

       83
       83
       +
       

     

       69
       84
        
       ```bash

     

       70
       85
        
       /ip address print

     

       71
       86
        
       /ip address add address=192.168.1.1/24 interface=ether3

     
···

       77
       92
        
       Default login: `admin` / (blank password)

     

       78
       93
        
       

     

       79
       94
        
       ### Rsync + Cron

     

       95
       95
       +
       

     

       80
       96
        
       **Rsync common patterns**:

     

       97
       97
       +
       

     

       81
       98
        
       ```bash

     

       82
       99
        
       rsync -av source/ dest/                             # Basic sync

     

       83
       100
        
       rsync -av --delete source/ dest/                    # Mirror (delete extra files in dest)

     
···

       87
       104
        
       ```

     

       88
       105
        
       

     

       89
       106
        
       **Cron syntax**: `minute hour day month weekday command`

     

       107
       107
       +
       

     

       90
       108
        
       ```

     

       91
       109
        
       0 2 * * * /path/to/backup.sh      # Daily at 2 AM

     

       92
       110
        
       */15 * * * * /path/to/script.sh   # Every 15 minutes

     
···

       95
       113
        
       

     

       96
       114
        
       ## Distribution Differences

     

       97
       115
        
       

     

       98
       98
       -
       | Feature | Ubuntu | Kali | CentOS/RHEL |

     

       99
       99
       -
       |---------|--------|------|-------------|

     

       100
       100
       -
       | Apache service | `apache2` | `apache2` | `httpd` |

     

       101
       101
       -
       | Network config | netplan YAML | interfaces | ifcfg-* scripts |

     

       102
       102
       -
       | Firewall | UFW | iptables | firewall-cmd |

     

       103
       103
       -
       | Cron service | `cron` | `cron` | `crond` |

     

       116
       116
       +
       | Feature        | Ubuntu       | Kali       | CentOS/RHEL      |

     

       117
       117
       +
       | -------------- | ------------ | ---------- | ---------------- |

     

       118
       118
       +
       | Apache service | `apache2`    | `apache2`  | `httpd`          |

     

       119
       119
       +
       | Network config | netplan YAML | interfaces | ifcfg-\* scripts |

     

       120
       120
       +
       | Firewall       | UFW          | iptables   | firewall-cmd     |

     

       121
       121
       +
       | Cron service   | `cron`       | `cron`     | `crond`          |

     

       104
       122
        
       

     

       105
       123
        
       **Router (2025)**: All distributions use MikroTik (replaces CentOS router)

     

       106
       124
        
       

     
···

       117
       135
        
       

     

       118
       136
        
       ## Critical Configuration Locations

     

       119
       137
        
       

     

       120
       120
       -
       | Service | Config File(s) |

     

       121
       121
       -
       |---------|---------------|

     

       122
       122
       -
       | SSH | `/etc/ssh/sshd_config` |

     

       123
       123
       -
       | Apache (Ubuntu) | `/etc/apache2/apache2.conf`, `/etc/apache2/sites-available/` |

     

       124
       124
       -
       | Apache (CentOS) | `/etc/httpd/conf/httpd.conf`, `/etc/httpd/conf.d/` |

     

       125
       125
       -
       | Network (Kali) | `/etc/network/interfaces` |

     

       126
       126
       -
       | Network (Ubuntu) | `/etc/netplan/*.yaml` |

     

       127
       127
       -
       | Network (CentOS) | `/etc/sysconfig/network-scripts/ifcfg-*` |

     

       128
       128
       -
       | DNS resolution | `/etc/resolv.conf` |

     

       129
       129
       -
       | Cron jobs | `crontab -e` (per-user), `/etc/crontab` (system-wide) |

     

       138
       138
       +
       | Service          | Config File(s)                                               |

     

       139
       139
       +
       | ---------------- | ------------------------------------------------------------ |

     

       140
       140
       +
       | SSH              | `/etc/ssh/sshd_config`                                       |

     

       141
       141
       +
       | Apache (Ubuntu)  | `/etc/apache2/apache2.conf`, `/etc/apache2/sites-available/` |

     

       142
       142
       +
       | Apache (CentOS)  | `/etc/httpd/conf/httpd.conf`, `/etc/httpd/conf.d/`           |

     

       143
       143
       +
       | Network (Kali)   | `/etc/network/interfaces`                                    |

     

       144
       144
       +
       | Network (Ubuntu) | `/etc/netplan/*.yaml`                                        |

     

       145
       145
       +
       | Network (CentOS) | `/etc/sysconfig/network-scripts/ifcfg-*`                     |

     

       146
       146
       +
       | DNS resolution   | `/etc/resolv.conf`                                           |

     

       147
       147
       +
       | Cron jobs        | `crontab -e` (per-user), `/etc/crontab` (system-wide)        |

     

       148
       148
       +
       

     

       149
       149
       +
       ## Credits

     

       150
       150
       +
       

     

       151
       151
       +
       These writeups are based on real NCAE competition experience and consolidate knowledge from:

     

       152
       152
       +
       

     

       153
       153
       +
       - NCAE Cyber Games competition materials

     

       154
       154
       +
       - Various Linux distribution documentation

     

       155
       155
       +
       - Hands-on competition debugging and troubleshooting

     

       156
       156
       +
       

     

       157
       157
       +
       > [!NOTE]

     

       158
       158
       +
       > The main repository is hosted on [tangled.org](https://tangled.org/dunkirk.sh/ncae-tools), with GitHub serving as a mirror.

     

       159
       159
       +
       

     

       160
       160
       +
       <p align="center">

     

       161
       161
       +
           <img src="https://raw.githubusercontent.com/taciturnaxolotl/carriage/master/.github/images/line-break.svg" />

     

       162
       162
       +
       </p>

     

       163
       163
       +
       

     

       164
       164
       +
       <p align="center">

     

       165
       165
       +
           &copy 2025-present <a href="https://github.com/taciturnaxolotl">Kieran Klukas</a>

     

       166
       166
       +
       </p>

     

       167
       167
       +
       

     

       168
       168
       +
       <p align="center">

     

       169
       169
       +
           <a href="https://github.com/taciturnaxolotl/ncae-tools/blob/main/LICENSE.md"><img src="https://img.shields.io/static/v1.svg?style=for-the-badge&label=License&message=MIT&logoColor=d9e0ee&colorA=363a4f&colorB=b7bdf8"/></a>

     

       170
       170
       +
       </p>