Stationeers hash function for Powershell using ntdll.dll's RtlComputeCrc32 and BitConverter

stationeers-hash.ps1

# This is free and unencumbered software released into the public domain.
# For more information, please refer to <https://unlicense.org>

function Get-IC10Hash {
    <#
    .SYNOPSIS
        Generate IC10 hash values for Stationeers game objects.

    .DESCRIPTION
        Converts a text string to an IC10 hash value (signed 32-bit CRC32) and its hex notation.
        The hex notation is compatible with IC10's $ hex literal format.

    .PARAMETER Text
        The text string to hash (e.g., "StructureGasAnalyser")
        Can also accept pipeline input.

    .EXAMPLE
        Get-IC10Hash "StructureGasAnalyser"

        Text                     Hash         Hex
        ----                     ----         ---
        StructureGasAnalyser     1876147318   $6FD3BC76

    .EXAMPLE
        Get-IC10Hash "StructureLiquidAnalyser"

        Text                      Hash          Hex
        ----                      ----          ---
        StructureLiquidAnalyser   -1789102802   $FFFFFFFF955C752E

    .EXAMPLE
        "StructureGasAnalyser", "StructureLiquidAnalyser" | Get-IC10Hash

        Text                      Hash          Hex
        ----                      ----          ---
        StructureGasAnalyser      1876147318    $6FD3BC76
        StructureLiquidAnalyser   -1789102802   $FFFFFFFF955C752E
    #>
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true, Position=0, ValueFromPipeline=$true)]
        [string]$Text
    )

    Begin {
        # Use Windows ntdll.dll native CRC32 function
        $signature = @'
        [DllImport("ntdll.dll")]
        public static extern uint RtlComputeCrc32(uint dwInitial, byte[] pData, int iLen);
'@

        # Only add the type if it hasn't been added yet
        if (-not ([System.Management.Automation.PSTypeName]'NtDll.Crc32').Type) {
            Add-Type -MemberDefinition $signature -Namespace "NtDll" -Name "Crc32"
        }
    }

    Process {
        $bytes = [System.Text.Encoding]::UTF8.GetBytes($Text)

        # Calculate CRC32 using native Windows function
        $crc32 = [NtDll.Crc32]::RtlComputeCrc32(0, $bytes, $bytes.Length)

        # Convert to signed 32-bit integer using BitConverter
        # This properly reinterprets the bytes without arithmetic conversion
        $crcBytes = [BitConverter]::GetBytes([uint32]$crc32)
        $hashValue = [BitConverter]::ToInt32($crcBytes, 0)

        # Generate hex notation
        if ($hashValue -lt 0) {
            # Negative: use 64-bit two's complement (16 hex digits)
            # For negatives, prepend FFFFFFFF to the unsigned 32-bit CRC hex
            $hexValue = '$FFFFFFFF' + $crc32.ToString("X8")
        } else {
            # Positive: compact format (strip leading zeros)
            $hexValue = '$' + $crc32.ToString("X")
        }

        # Output as custom object for better formatting
        [PSCustomObject]@{
            Text = $Text
            Hash = $hashValue
            Hex = $hexValue
        }
    }
}

# Create alias for shorter usage
#Set-Alias -Name ic10hash -Value Get-IC10Hash