/// <summary>
/// Restores a Cryptographic key from previously exported file. Use to transfer key to new computer
/// </summary>
/// <param name="ImportFile">Previously exported symmetric key to be restored</param>
/// <param name="Password">Password used to secure previously exported key</param>
/// <param name="NewProviderKey">Location and filename of key to be restored.</param>
/// <returns></returns>
public static RestoreSecureKeyResult Restore(FileInfo ImportFile,
string Password,
string NewProviderKey)
{
RestoreSecureKeyResult result = new RestoreSecureKeyResult
{
IsInError = false,
ImportFile = ImportFile.FullName,
RestoredKey = NewProviderKey,
Password = Password
};
ProtectedKey RestoredSecureKey;
KeyManager.ClearCache();
try
{
using (FileStream fs = File.OpenRead(ImportFile.FullName))
{
RestoredSecureKey = KeyManager.RestoreKey(fs, Password, DataProtectionScope.LocalMachine);
}
using (FileStream ofs = File.OpenWrite(NewProviderKey))
{
KeyManager.Write(ofs, RestoredSecureKey);
}
} catch (Exception ex)
{
result.IsInError = true;
result.ErrorString = ex.Message.ToString();
if (result.ErrorString.StartsWith("Padding is invalid and cannot be removed"))
{
result.ErrorString += "\nIt may be due to an incorrect password.";
}
result.Exception = ex;
}
return(result);
}
public static int RunRestore(Options.RestoreKey RestoreKeyOpts)
{
// Checks
int inError = 0;
StringBuilder errMsgText = new StringBuilder();
if (!File.Exists(RestoreKeyOpts.ArchiveFile))
{
// Import file Doesn't exist
inError = 1;
errMsgText.Append($"- Provided import file, '{RestoreKeyOpts.ArchiveFile}', doesn't exist.\n");
}
try
{
using (FileStream tfs = File.OpenWrite(RestoreKeyOpts.OutputKeyFile))
{ }
} catch (UnauthorizedAccessException)
{
inError = 2;
errMsgText.Append($"- Unable to open output file, '{RestoreKeyOpts.OutputKeyFile}', for writting\n");
} catch (DirectoryNotFoundException)
{
inError = 3;
errMsgText.Append($"- Directory not found, cannot create output file: '{RestoreKeyOpts.OutputKeyFile}'\n");
} catch (Exception ex)
{
inError = 9;
errMsgText.Append($"- Unknown error encountered:\n{ex.Message}\n");
}
if (RestoreKeyOpts.Password.Trim() == string.Empty)
{
inError = 4;
errMsgText.Append($"- Provided password value is empty or contains only whitespace\n");
}
if (inError > 0)
{
Console.Write($"\nThere is a problem with the provided parameters:\n\n{errMsgText.ToString()}\n\n");
return(inError);
}
// Work
FileInfo importFile = new FileInfo(RestoreKeyOpts.ArchiveFile);
RestoreSecureKeyResult result = RestoreSecureKey.Restore(importFile, RestoreKeyOpts.Password, RestoreKeyOpts.OutputKeyFile);
if (result.IsInError)
{
Console.Write($"\nUnable to restore secure key. Exception message is:\n{result.ErrorString}\n");
return(5);
}
if (File.Exists(RestoreKeyOpts.OutputKeyFile) && new FileInfo(RestoreKeyOpts.OutputKeyFile).Length > 10)
{
Console.Write($"\nKey, {RestoreKeyOpts.OutputKeyFile}, created successfully!\n");
return(0);
}
else
{
Console.Write($"\nKey, {RestoreKeyOpts.OutputKeyFile}, creation failed!\n");
return(-1);
}
}