/// <summary>
/// Export this <see cref="EncryptionKeyPair"/> into a PEM file.
/// </summary>
/// <param name="path">Only path name. DO NOT include filename.</param>
/// <param name="filename">
/// Filename to export, if not specified it sets to pub.key/priv.key adequately.
/// DO NOT include extension.
/// </param>
/// <param name="includePrivate">On exporting to file include private key content, otherwise false</param>
/// <exception cref="ArgumentNullException">Directory not specified.</exception>
/// <exception cref="ArgumentException">Directory not found.</exception>
/// <exception cref="InvalidOperationException">Error when exporting key.</exception>
public void ExportAsPEMFile(string path, string filename = "key", bool includePrivate = false)
{
if (string.IsNullOrWhiteSpace(path))
{
throw new ArgumentNullException(
paramName: nameof(path),
message: "Directory not specified.");
}
if (!Directory.Exists(path))
{
throw new ArgumentException(
paramName: nameof(path),
message: "Directory not found.");
}
// trying to export private key from a public key
if (PublicOnly && includePrivate)
{
throw new InvalidOperationException(
message: "Impossible to export private content from a public key.");
}
using (var rsa = new RSACryptoServiceProvider(this.KeySize))
{
try
{
rsa.ImportParameters(this.RSAParameters);
if (includePrivate)
{
filename = "priv." + filename + ".pem";
string fileContent = rsa.ExportRSAPrivateKeyAsPEM();
FileManipulation.SaveFile(fileContent.ToByteArray(), path, filename, attributes: FileAttributes.ReadOnly);
}
else
{
filename = "pub." + filename + ".pem";
string fileContent = rsa.ExportRSAPublicKeyAsPEM();
FileManipulation.SaveFile(fileContent.ToByteArray(), path, filename, attributes: FileAttributes.ReadOnly);
}
}
finally
{
rsa.PersistKeyInCsp = false;
}
}
}