Challenge Flags

As a Challenge Designer, the challenge flag generation allows you to define what flags your challenge supports.

For example, a rot13 cipher may not support special characters. If your challenge does not support dynamic flags, this field not required.

Basic Structure

{
  "name": "Challenge Name",
  "customFlag": {
    "allowedCharacters": string | {
        "lowercase": boolean,
        "uppercase": boolean,
        "numbers": boolean,
        "specialCharacters": boolean | string
    },
    "length": {
        "min": number,
        "max": number
    }
  }
  //...
}

Allowed Characters

You can specify allowed characters in two ways:

1. Explicit Character Set (String)

Provide an exact string of allowed characters:

{
  "customFlag": {
    "allowedCharacters": "01" //binary
  }
}

{
  "customFlag": {
    "allowedCharacters": "0123456789abcdef" // Hexadecimal
  }
}

{
  "customFlag": {
    "allowedCharacters": "ACGT" // DNA sequences
  }
}

{
  "customFlag": {
    "allowedCharacters": "abc123!@#" // Custom Set
  }
}

2. Character Categories (Object)

Build a character set from predefined categories:

{
  "customFlag": {
    "allowedCharacters": {
      "lowercase": true,
      "uppercase": true,
      "numbers": true,
      "specialCharacters": true
    }
  }
}

Generation Fields

Field	Type	required	default	Description
allowedCharacters	string	true	object/string	Either an explicit character set string or an object with character categories
lowercase	boolean	false	true	Include lowercase letters [a-z] (default: true)
uppercase	boolean	false	true	Include uppercase letters [A-Z] (default: true)
numbers	boolean	false	true	Include numbers [0-9] (default: true)
specialCharacters	boolean	false	false	string
length.min	number	false	1	The minimum length supported for the flag (default: 1)
length.max	number	false	MAX_SAFE_INTEGER	The maximum length supported for the flag (default: MAX_SAFE_INTEGER)

Examples

Binary challenge (only 0 and 1):

{
  "customFlag": {
    "allowedCharacters": "01",
    "length": {
      "min": 8,
      "max": 16
    }
  }
}

Alphanumeric only (no special characters):

{
  "customFlag": {
    "allowedCharacters": {
      "lowercase": true,
      "uppercase": true,
      "numbers": true,
      "specialCharacters": false
    }
  }
}

With specific special characters:

{
  "customFlag": {
    "allowedCharacters": {
      "lowercase": true,
      "uppercase": true,
      "numbers": true,
      "specialCharacters": "!@#$%"
    }
  }
}

With emojis:

{
  "customFlag": {
    "allowedCharacters": {
      "lowercase": true,
      "uppercase": false,
      "numbers": true,
      "specialCharacters": "😀😁😂🎉"
    }
  }
}