Private/ConvertFrom-BCKey.ps1
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function ConvertFrom-BCKey { [CmdletBinding()] [OutputType('System.Security.Cryptography.AsymmetricAlgorithm')] param( [Parameter(Mandatory,Position=0,ValueFromPipeline)] [Org.BouncyCastle.Crypto.AsymmetricCipherKeyPair]$BCKeyPair ) if ($BCKeyPair.Private -is [Org.BouncyCastle.Crypto.Parameters.ECPrivateKeyParameters]) { $pKey = $BCKeyPair.Private # convert the curve $Curve = switch ($pKey.Parameters.Curve.GetType().Name) { 'SecP256R1Curve' { [Security.Cryptography.ECCurve+NamedCurves]::nistP256; break } 'SecP384R1Curve' { [Security.Cryptography.ECCurve+NamedCurves]::nistP384; break } 'SecP521R1Curve' { [Security.Cryptography.ECCurve+NamedCurves]::nistP521; break } default { throw "Unsupported curve found." } } # add public params $Q = New-Object Security.Cryptography.ECPoint $Q.X = $BCKeyPair.Public.Q.AffineXCoord.GetEncoded() $Q.Y = $BCKeyPair.Public.Q.AffineYCoord.GetEncoded() $keyParams = New-Object Security.Cryptography.ECParameters $keyParams.Q = $Q $keyParams.Curve = $Curve # add private param # For named curves (which is all we're currently using), D must have the same # length as X/Y params. But D doesn't have a GetEncoded() method which takes care # of padding the byte array like X/Y. So we have to check for proper padding and do # it manually. $dBytes = $pKey.D.ToByteArrayUnsigned() if ($dBytes.Length -ne $Q.X.Length) { $paddedD = New-Object byte[] $Q.X.Length $startAt = $paddedD.Length - $dBytes.Length [Array]::Copy($dBytes, 0, $paddedD, $startAt, $dBytes.Length) # set the padded D value $keyParams.D = $paddedD } else { # set the D value as-is because it doesn't need padding $keyParams.D = $dBytes } # create the key $key = [Security.Cryptography.ECDsa]::Create() $key.ImportParameters($keyParams) return $key } elseif ($BCKeyPair.Private -is [Org.BouncyCastle.Crypto.Parameters.RsaPrivateCrtKeyParameters]) { $pKey = $BCKeyPair.Private $keyParams = New-Object Security.Cryptography.RSAParameters $keyParams.Exponent = $pKey.PublicExponent.ToByteArrayUnsigned() $keyParams.Modulus = $pKey.Modulus.ToByteArrayUnsigned() $keyParams.D = $pKey.Exponent.ToByteArrayUnsigned() $keyParams.P = $pKey.P.ToByteArrayUnsigned() $keyParams.Q = $pKey.Q.ToByteArrayUnsigned() $keyParams.DP = $pKey.DP.ToByteArrayUnsigned() $keyParams.DQ = $pKey.DQ.ToByteArrayUnsigned() $keyParams.InverseQ = $pKey.QInv.ToByteArrayUnsigned() # create the key $key = New-Object Security.Cryptography.RSACryptoServiceProvider $key.ImportParameters($keyParams) return $key } else { # not EC or RSA...don't know what to do with it throw "Unsupported key type." } } |