Private/RSAHelper.ps1
function ExportPrivateKeyFromRSA( [System.Security.Cryptography.RSAParameters]$RSAParams ){ [byte]$Sequence = 0x30 [byte[]]$Version =(0x00) $stream = [System.IO.MemoryStream]::new() $writer = [System.IO.BinaryWriter]::new($stream) $writer.Write($Sequence); # SEQUENCE $innerStream = [System.IO.MemoryStream]::new() $innerWriter = [System.IO.BinaryWriter]::new($innerStream) EncodeIntegerBigEndian $innerWriter $Version EncodeIntegerBigEndian $innerWriter $RSAParams.Modulus EncodeIntegerBigEndian $innerWriter $RSAParams.Exponent EncodeIntegerBigEndian $innerWriter $RSAParams.D EncodeIntegerBigEndian $innerWriter $RSAParams.P EncodeIntegerBigEndian $innerWriter $RSAParams.Q EncodeIntegerBigEndian $innerWriter $RSAParams.DP EncodeIntegerBigEndian $innerWriter $RSAParams.DQ EncodeIntegerBigEndian $innerWriter $RSAParams.InverseQ $length = ([int]($innerStream.Length)) EncodeLength $writer $length $writer.Write($innerStream.GetBuffer(), 0, $length) $base64 = [Convert]::ToBase64String($stream.GetBuffer(), 0, ([int]($stream.Length))) $offset = 0 $line_length = 64 $sb = [System.Text.StringBuilder]::new() [void]$sb.AppendLine("-----BEGIN RSA PRIVATE KEY-----") while ($offset -lt $base64.Length) { $line_end = [Math]::Min($offset + $line_length, $base64.Length) [void]$sb.AppendLine($base64.Substring($offset, $line_end - $offset)) $offset = $line_end } [void]$sb.AppendLine("-----END RSA PRIVATE KEY-----") return $sb.ToString() } function EncodeLength( [System.IO.BinaryWriter]$stream, [int]$length ){ [byte]$bytex80 = 0x80 if($length -lt 0){ throw "Length must be non-negative" } if($length -lt $bytex80){ $stream.Write(([byte]$length)) } else{ $temp = $length $bytesRequired = 0; while ($temp -gt 0) { $temp = $temp -shr 8 $bytesRequired++ } [byte]$byteToWrite = $bytesRequired -bor $bytex80 $stream.Write($byteToWrite) $iValue = ($bytesRequired - 1) [byte]$0ffByte = 0xff for ($i = $iValue; $i -ge 0; $i--) { [byte]$byteToWrite = ($length -shr (8 * $i) -band $0ffByte) $stream.Write($byteToWrite ) } } } function EncodeIntegerBigEndian( [System.IO.BinaryWriter]$stream, [byte[]]$value, [bool]$forceUnsigned = $true ) { [byte]$Integer = 0x02 $stream.Write($Integer); # INTEGER $prefixZeros = 0 for ($i = 0; $i -lt $value.Length; $i++) { if ($value[$i] -ne 0){break} $prefixZeros++ } if(($value.Length - $prefixZeros) -eq 0){ EncodeLength $stream 1 $stream.Write(([byte]0)) } else{ [byte]$newByte = 0x7f if(($forceUnsigned) -AND ($value[$prefixZeros] -gt $newByte)){ EncodeLength $stream ($value.Length - $prefixZeros +1) $stream.Write(([byte]0)) } else{ EncodeLength $stream ($value.Length - $prefixZeros) } for ($i = $prefixZeros; $i -lt $value.Length; $i++) { $stream.Write($value[$i]) } } } |