wietze-Invoke-ArgFuscator/Modifiers/Regex.psm1

using module "..\Types\Modifier.psm1"
using module "..\Types\Token.psm1"
using module "..\Types\Argument.psm1"

# 'Regex' is taken, hence 'RegularExpression'
class RegularExpression : Modifier {
    [float]$Probability;
    [string]$RegexMatch;
    [string]$RegexReplace;

    RegularExpression([Token[]]$InputCommandTokens, [string[]]$AppliesTo, [Argument[]]$Arguments, [float]$Probability, [string]$RegexMatch, [string]$RegexReplace, [boolean]$CaseSensitive) : base($InputCommandTokens, $AppliesTo, $Arguments, $Probability) {
        $this.RegexMatch = $RegexMatch;
        if (!$CaseSensitive) {
            $this.RegexMatch = "(?i)" + $this.RegexMatch;
        }
        $this.RegexReplace = $RegexReplace;
    }

    [void]GenerateOutput() {
        foreach ($Token in $this.InputCommandTokens) {
            $NewTokenContent = $Token.ToString();

            if ($this.AppliesTo.Contains($Token.Type) -and [Modifier]::CoinFlip($this.Probability)) {
                $RegexReplacer = [regex]::replace($this.RegexReplace, "\`$(\d+)\[(\d+):(\d+(?:-x?(?:\d+)?)?)\]", {
                        [int]$rIndex = $args[0].groups[1].value
                        [int]$start = $args[0].groups[2].value
                        [string]$end = $args[0].groups[3].value
                        if ($NewTokenContent -match $this.RegexMatch) {
                            $match = $Matches[$rIndex]
                            if ($end.IndexOf('-') -ge 0) {
                                $ids = $end.split('-')
                                if ($ids[1] -eq '') { $ids[1] = $match.length; }
                                [int]$end = Get-Random -Minimum ([int]($ids[0])) -Maximum ([int]($ids[1]));
                            }
                            return $match.substring($start, $end);
                        }
                        return $args[0].value;
                    });

                $RegexMatchr = $this.RegexMatch -replace "`$RANDOM", ( -join ((65..90) + (97..122) | Get-Random -Count (Get-Random -minimum 1 -Maximum 20) | ForEach-Object { [char]$_ }))

                $NewTokenContent = [regex]::replace($NewTokenContent, $RegexMatchr, $RegexReplacer)
                $Token.TokenContent = $NewTokenContent;
            }
        }
    }
}