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Documentation Index

Fetch the complete documentation index at: https://mintlify.com/GZTimeWalker/GZCTF/llms.txt

Use this file to discover all available pages before exploring further.

Games (also called competitions or events) are time-bound CTF competitions where teams compete to solve challenges and earn points.

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Game Lifecycle

A game in GZCTF progresses through several states:

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Game States

1

Before Start

Teams can register, but challenges are not accessible. Administrators can configure challenges and settings.
2

Active

The competition is live. Teams can access challenges, submit flags, and earn points. The game is considered active when:
StartTimeUtc <= DateTimeOffset.Now && DateTimeOffset.Now <= EndTimeUtc
3

Ended

Competition time has expired. Depending on configuration:
  • Practice Mode Enabled: Teams can still solve challenges (no scoring/ranking changes)
  • Practice Mode Disabled: Challenges become inaccessible
4

Writeup Submission

If writeups are required, teams must submit before the writeup deadline.

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Game Configuration

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Basic Information

PropertyDescription
TitleGame name displayed to participants
SummaryBrief description shown in game listings
ContentDetailed introduction with rules and information
PosterHashGame poster image
HiddenHide game from public listings

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Timing

All times use UTC with DateTimeOffset for timezone accuracy. 
public DateTimeOffset StartTimeUtc { get; set; }
public DateTimeOffset EndTimeUtc { get; set; }
public DateTimeOffset WriteupDeadline { get; set; }

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Participation Settings

Team Registration 
AcceptWithoutReview = true
Teams are automatically accepted when they register.
Team Constraints 
// Limit team size (0 = no limit)
public int TeamMemberCountLimit { get; set; }

// Limit simultaneous containers per team
public int ContainerCountLimit { get; set; } = 3;

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Writeup Configuration

Writeups are post-competition technical reports where teams explain their solutions.
public bool WriteupRequired { get; set; }
public DateTimeOffset WriteupDeadline { get; set; }
public string WriteupNote { get; set; } // Instructions for participants
When WriteupRequired is true:
  • Teams must submit writeups before the deadline
  • Writeups can be reviewed and downloaded by administrators
  • Teams without writeups may have different participation status

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Scoring Configuration

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Blood Bonuses

The first three teams to solve each challenge receive bonus points: 
public BloodBonus BloodBonus { get; set; }

// Default values:
// First blood:  +50% (1.5x multiplier)
// Second blood: +30% (1.3x multiplier)
// Third blood:  +10% (1.1x multiplier)
Blood bonus percentages are stored as integers (parts per thousand) for precision:
  • 50 = 5.0% bonus
  • 300 = 30.0% bonus
  • 500 = 50.0% bonus
The blood bonus is encoded as a single long value: 
BloodBonusValue = (FirstBlood << 20) + (SecondBlood << 10) + ThirdBlood
DefaultValue = (50 << 20) + (30 << 10) + 10  // 50%, 30%, 10%

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Dynamic Scoring

See Scoring for detailed information about the dynamic scoring formula.

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Security Features

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Team Tokens

Each team participation generates a unique signed token: 
public string PublicKey { get; set; }  // Ed25519 public key
public string PrivateKey { get; set; } // Ed25519 private key (encrypted)
Tokens are used for:
  • Dynamic flag generation
  • Team-specific challenge instances
  • Preventing flag sharing detection

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Team Hash Salt

A game-specific salt ensures flag uniqueness: 
public string TeamHashSalt => $"GZCTF@{PrivateKey}@PK".ToSHA256String();

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Practice Mode

Practice mode allows most operations to continue after the game ends, but rankings and scoring are frozen.
public bool PracticeMode { get; set; } = true;
When enabled:
  • Challenges remain accessible after EndTimeUtc
  • Teams can still solve challenges
  • Scores and rankings are not updated
  • New teams cannot join
  • Useful for learning and practicing

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Divisions

Games can be divided into separate divisions (tracks) for different participant groups: 
public HashSet<Division>? Divisions { get; set; }
Divisions allow:
  • Separate scoreboards per division
  • Different challenge visibility per division
  • Division-specific permissions and invite codes
See Teams for more details.

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Game Model Reference

The Game model is located at: 
~/workspace/source/src/GZCTF/Models/Data/Game.cs

public partial class Game
{
    public int Id { get; set; }
    public string Title { get; set; }
    public string Summary { get; set; }
    public string Content { get; set; }
    public string? PosterHash { get; set; }
    public bool Hidden { get; set; }
    
    // Timing
    public DateTimeOffset StartTimeUtc { get; set; }
    public DateTimeOffset EndTimeUtc { get; set; }
    public DateTimeOffset WriteupDeadline { get; set; }
    
    // Configuration
    public bool PracticeMode { get; set; } = true;
    public bool AcceptWithoutReview { get; set; }
    public bool WriteupRequired { get; set; }
    public string? InviteCode { get; set; }
    public int TeamMemberCountLimit { get; set; }
    public int ContainerCountLimit { get; set; } = 3;
    
    // Scoring
    public BloodBonus BloodBonus { get; set; }
    
    // Security
    public string PublicKey { get; set; }
    public string PrivateKey { get; set; }
    
    // Relationships
    public HashSet<GameChallenge> Challenges { get; set; }
    public HashSet<Participation> Participations { get; set; }
    public HashSet<Team>? Teams { get; set; }
    public HashSet<Division>? Divisions { get; set; }
    public List<GameEvent> GameEvents { get; set; }
    public List<GameNotice> GameNotices { get; set; }
    public List<Submission> Submissions { get; set; }
}

Challenges

Learn about challenge types and configuration

Teams & Participation

Understand how teams join and participate

Scoring System

Explore dynamic scoring and blood bonuses

Containers

Manage container-based challenges

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