private/New-OTPQRCode.ps1
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# New-OTPQRCode.ps1 <# .SYNOPSIS Generates a QR code for OTP configuration. .DESCRIPTION The New-OTPQRCode function generates a QR code image from an OTP configuration URI. It accepts input directly or through the pipeline from New-OTPSecret, allowing for easy creation of QR codes for TOTP/HOTP configurations. The generated QR code can be saved to a file, displayed directly, or both. Features: - Generates high-quality QR codes suitable for scanning - Supports both file output and byte array return - Validates URI format before generation - Customizable QR code size - Configurable error correction - Clean disposal of resources - Option to display the QR code immediately The generated QR codes are compatible with common authenticator apps: - Google Authenticator - Microsoft Authenticator - Authy - And other RFC-compliant authenticators .PARAMETER Uri The OTP configuration URI to encode in the QR code. Must start with 'otpauth://'. This parameter accepts pipeline input from New-OTPSecret and other functions that output OTP configuration URIs. .PARAMETER Size The size of the QR code image in pixels. Must be between 100 and 1000. Default value is 300 pixels. .PARAMETER OutFile Optional path where the QR code image will be saved. If not specified, the QR code will be displayed in the default image viewer. .PARAMETER Show If specified, displays the QR code in the default image viewer. This can be used with or without the OutFile parameter. .EXAMPLE PS> New-OTPSecret | New-OTPQRCode -Show Generates a new OTP secret and displays the QR code. .EXAMPLE PS> New-OTPSecret -Length 32 -Tag "MyApp" | New-OTPQRCode -Size 400 -OutFile "myapp_qr.png" -Show Creates a 32-character OTP secret with a tag, generates a 400x400 pixel QR code, saves it to myapp_qr.png, and displays it. .EXAMPLE PS> $uri = "otpauth://totp/Example:alice@google.com?secret=JBSWY3DPEHPK3PXP&issuer=Example" PS> New-OTPQRCode -Uri $uri -Size 500 -Show Creates a 500x500 pixel QR code from a manually specified OTP URI and displays it. .NOTES The function validates that the URI starts with 'otpauth://' to ensure compatibility with OTP authenticator apps. When using pipeline input from New-OTPSecret, the URI is automatically formatted correctly. Best practices: - Use PNG format for best quality - Size of 300-400 pixels works well on most devices - Ensure adequate contrast in the display environment - Test scanning with various authenticator apps .LINK https://github.com/thorstenbutz/otp https://github.com/google/google-authenticator/wiki/Key-Uri-Format #> function New-OTPQRCode { [CmdletBinding(SupportsShouldProcess, DefaultParameterSetName = 'Save')] param( [Parameter(Mandatory, ValueFromPipeline, ValueFromPipelineByPropertyName)] [ValidateNotNullOrEmpty()] [Alias('OTPUri')] [string]$Uri, [Parameter()] [ValidateRange(100, 1000)] [int]$Size = 300, [Parameter(ParameterSetName = 'Save')] [Parameter(ParameterSetName = 'Show', Mandatory)] [ValidateNotNullOrEmpty()] [string]$OutFile, [Parameter(ParameterSetName = 'Save')] [Parameter(ParameterSetName = 'Show', Mandatory)] [switch]$Show ) begin { Add-Type -AssemblyName System.Drawing $zxingPath = Join-Path -Path $PSScriptRoot -ChildPath '..\lib\zxing.dll' if (-not (Test-Path -Path $zxingPath)) { throw "Required ZXing.Net library not found at: $zxingPath" } Add-Type -Path $zxingPath } process { try { if (-not $Uri.StartsWith('otpauth://')) { throw 'Invalid OTP URI format. URI must start with ''otpauth://''' } Write-Verbose -Message "Generating QR code with size: ${Size}x${Size} pixels" Write-Verbose -Message "URI length: $($Uri.Length) characters" $barcodeWriter = [ZXing.BarcodeWriter]::new() $barcodeWriter.Format = [ZXing.BarcodeFormat]::QR_CODE $options = [ZXing.QrCode.QrCodeEncodingOptions]::new() $options.Height = $Size $options.Width = $Size $options.Margin = 2 $options.ErrorCorrection = [ZXing.QrCode.Internal.ErrorCorrectionLevel]::M $options.CharacterSet = 'UTF-8' $options.DisableECI = $true $barcodeWriter.Options = $options $qrBitmap = $barcodeWriter.Write($Uri) # Save to file if OutFile is specified if ($OutFile) { ## Check if file exists and prompt for overwrite confirmation $fileExists = Test-Path -Path $OutFile if ($fileExists) { ## Check if confirmation was explicitly disabled $skipConfirmation = ($PSBoundParameters.ContainsKey('Confirm') -and $PSBoundParameters['Confirm'] -eq $false) if (-not $skipConfirmation) { ## Prompt for overwrite confirmation $shouldOverwrite = $PSCmdlet.ShouldContinue( "The file '$OutFile' already exists. Do you want to overwrite it?", 'Confirm Overwrite' ) if (-not $shouldOverwrite) { Write-Verbose -Message "File overwrite cancelled by user: $OutFile" return } } else { Write-Verbose -Message "Skipping overwrite confirmation due to -Confirm:`$false" } } ## Proceed with file operation using ShouldProcess $actionMessage = if ($fileExists) { 'Overwrite existing QR code image' } else { 'Save QR code image' } if ($PSCmdlet.ShouldProcess($OutFile, $actionMessage)) { $directory = [System.IO.Path]::GetDirectoryName($OutFile) if (-not [string]::IsNullOrEmpty($directory) -and -not (Test-Path -Path $directory)) { New-Item -ItemType Directory -Path $directory -Force | Out-Null } $imageFormat = [System.Drawing.Imaging.ImageFormat]::Png $encoderParams = [System.Drawing.Imaging.EncoderParameters]::new(1) $encoderParams.Param[0] = [System.Drawing.Imaging.EncoderParameter]::new( [System.Drawing.Imaging.Encoder]::Quality, [long]100 ) $qrBitmap.Save($OutFile, $imageFormat) $verboseMessage = if ($fileExists) { "QR code overwritten at: $OutFile" } else { "QR code saved to: $OutFile" } Write-Verbose -Message $verboseMessage $outputFile = Get-Item -Path $OutFile # Display the QR code if Show is specified if ($Show) { Start-Process -FilePath $OutFile Write-Verbose -Message "QR code displayed from: $OutFile" } # Return the output file $outputFile } } } catch { Write-Error -ErrorRecord $_ } finally { if ($qrBitmap) { $qrBitmap.Dispose() } if ($encoderParams) { $encoderParams.Dispose() } } } } |