Public/Export-PrivateKey.ps1
|
# src: https://gist.github.com/therightstuff/aa65356e95f8d0aae888e9f61aa29414 function Export-PrivateKey { param ( [Parameter(Mandatory = $true, Position = 0 )] [System.Security.Cryptography.RSACryptoServiceProvider]$csp ) $outputStream = [System.IO.StringWriter]::new() if ($csp.PublicOnly) { throw [System.ArgumentException]::new("CSP does not contain a private key", "csp") } $parameters = $csp.ExportParameters($true); Use ($stream = [System.IO.MemoryStream]::new()) { $writer = [System.IO.BinaryWriter]::new($stream); $writer.Write([byte]0x30); # SEQUENCE Use ($innerStream = [System.IO.MemoryStream]::new()) { $innerWriter = [System.IO.BinaryWriter]::new($innerStream); EncodeIntegerBigEndian $innerWriter @([byte]0x00) EncodeIntegerBigEndian $innerWriter $parameters.Modulus EncodeIntegerBigEndian $innerWriter $parameters.Exponent EncodeIntegerBigEndian $innerWriter $parameters.D EncodeIntegerBigEndian $innerWriter $parameters.P EncodeIntegerBigEndian $innerWriter $parameters.Q EncodeIntegerBigEndian $innerWriter $parameters.DP EncodeIntegerBigEndian $innerWriter $parameters.DQ EncodeIntegerBigEndian $innerWriter $parameters.InverseQ [int]$length = $innerStream.Length; EncodeLength $writer $length $writer.Write($innerStream.GetBuffer(), 0, $length); } $base64 = [System.Convert]::ToBase64String($stream.GetBuffer(), 0, [int]$stream.Length).ToCharArray(); $outputStream.Write("-----BEGIN RSA PRIVATE KEY-----`n"); for ($i = 0; $i -lt $base64.Length; $i += 64) { $outputStream.Write($base64, $i, [System.Math]::Min(64, $base64.Length - $i)); $outputStream.Write("`n"); } $outputStream.Write("-----END RSA PRIVATE KEY-----"); } return $outputStream.ToString(); } |