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duplicati/Duplicati/Library/Encryption/GPGEncryption.cs
T

293 lines
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C#

#region Disclaimer / License
// Copyright (C) 2015, The Duplicati Team
// http://www.duplicati.com, info@duplicati.com
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
//
#endregion
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using Duplicati.Library.Interface;
namespace Duplicati.Library.Encryption
{
/// <summary>
/// Implements a encryption/decryption with the GNU Privacy Guard (GPG)
/// </summary>
public class GPGEncryption : EncryptionBase
{
#region Commandline option constants
/// <summary>
/// The commandline option supplied if armor should be disabled (--gpg-encryption-disable-armor)
/// </summary>
private const string COMMANDLINE_OPTIONS_DISABLE_ARMOR = "gpg-encryption-disable-armor";
/// <summary>
/// The commandline option supplied if armor should be enabled (--gpg-encryption-enable-armor)
/// </summary>
private const string COMMANDLINE_OPTIONS_ENABLE_ARMOR = "gpg-encryption-enable-armor";
/// <summary>
/// The commandline option supplied if the encryption should have non-default switches (--gpg-encryption-switches)
/// </summary>
private const string COMMANDLINE_OPTIONS_ENCRYPTION_OPTIONS = "gpg-encryption-switches";
/// <summary>
/// The commandline option supplied if the decryption should have non-default switches (--gpg-decryption-switches)
/// </summary>
private const string COMMANDLINE_OPTIONS_DECRYPTION_OPTIONS = "gpg-decryption-switches";
/// <summary>
/// The commandline option supplied, indicating the path to the GPG program executable (--gpg-program-path)
/// </summary>
public const string COMMANDLINE_OPTIONS_PATH = "gpg-program-path";
/// <summary>
/// The commandline option that changes the default encryption command (--gpg-encryption-command)
/// </summary>
private const string COMMANDLINE_OPTIONS_ENCRYPTION_COMMAND = "gpg-encryption-command";
/// <summary>
/// The commandline option that changes the default encryption command (--gpg-decryption-command)
/// </summary>
private const string COMMANDLINE_OPTIONS_DECRYPTION_COMMAND = "gpg-decryption-command";
#endregion
/// <summary>
/// Always present commandline options (--passphrase-fd 0)
/// </summary>
private const string GPG_COMMANDLINE_STANDARD_OPTIONS = "--batch --passphrase-fd 0";
/// <summary>
/// The options that are supplied as default when encrypting (default is empty)
/// </summary>
private const string GPG_ENCRYPTION_DEFAULT_OPTIONS = "";
/// <summary>
/// The options that are supplied as default when encrypting (default is empty)
/// </summary>
private const string GPG_DECRYPTION_DEFAULT_OPTIONS = "";
/// <summary>
/// The commandline option that specifies that armor is used (--armor)
/// </summary>
private const string GPG_ARMOR_OPTION = "--armor";
/// <summary>
/// The command used to signal encryption (--symmetric)
/// </summary>
private const string GPG_ENCRYPTION_COMMAND = "--symmetric";
/// <summary>
/// The command used to signal decryption (--decrypt)
/// </summary>
private const string GPG_DECRYPTION_COMMAND = "--decrypt";
/// <summary>
/// The PGP program to use, should be with absolute path
/// </summary>
private string m_programpath = "gpg";
/// <summary>
/// Commandline switches for encryption
/// </summary>
private string m_encryption_args;
/// <summary>
/// Commandline switches for decryption
/// </summary>
private string m_decryption_args;
/// <summary>
/// The key used for cryptographic operations
/// </summary>
private string m_key;
/// <summary>
/// Constructs a GPG instance for reading the interface values
/// </summary>
public GPGEncryption()
{
}
/// <summary>
/// Constructs a new GPG instance
/// </summary>
/// <param name="options">The options passed on the commandline</param>
/// <param name="passphrase">The passphrase to be used for encryption</param>
public GPGEncryption(string passphrase, Dictionary<string, string> options)
{
m_key = passphrase;
//NOTE: For reasons unknown, GPG commandline options are divided into "options" and "commands".
//NOTE: The "options" must be placed before "commands" or it wont work!
bool enableArmor = false;
if (options.ContainsKey(COMMANDLINE_OPTIONS_ENABLE_ARMOR))
{
enableArmor = Utility.Utility.ParseBoolOption(options, COMMANDLINE_OPTIONS_ENABLE_ARMOR);
}
else
{
//Special handling of this option, it should have been --enable-armor instead,
//so this is now deprecated
if (options.ContainsKey(COMMANDLINE_OPTIONS_DISABLE_ARMOR))
enableArmor = !Utility.Utility.ParseBoolOption(options, COMMANDLINE_OPTIONS_DISABLE_ARMOR);
}
if (enableArmor)
{
//--armor is an option
m_encryption_args += GPG_ARMOR_OPTION;
m_decryption_args += GPG_ARMOR_OPTION;
}
//--passphrase-fd is an option
m_encryption_args += " " + GPG_COMMANDLINE_STANDARD_OPTIONS;
m_decryption_args += " " + GPG_COMMANDLINE_STANDARD_OPTIONS;
if (options.ContainsKey(COMMANDLINE_OPTIONS_ENCRYPTION_OPTIONS))
m_encryption_args += " " + options[COMMANDLINE_OPTIONS_ENCRYPTION_OPTIONS];
else
m_encryption_args += " " + GPG_ENCRYPTION_DEFAULT_OPTIONS;
if (options.ContainsKey(COMMANDLINE_OPTIONS_DECRYPTION_OPTIONS))
m_decryption_args += " " + options[COMMANDLINE_OPTIONS_DECRYPTION_OPTIONS];
else
m_decryption_args += " " + GPG_DECRYPTION_DEFAULT_OPTIONS;
//These are commands and thus inserted last
if (options.ContainsKey(COMMANDLINE_OPTIONS_ENCRYPTION_COMMAND))
m_encryption_args += " " + options[COMMANDLINE_OPTIONS_ENCRYPTION_COMMAND];
else
m_encryption_args += " " + GPG_ENCRYPTION_COMMAND;
if (options.ContainsKey(COMMANDLINE_OPTIONS_DECRYPTION_COMMAND))
m_decryption_args += " " + options[COMMANDLINE_OPTIONS_DECRYPTION_COMMAND];
else
m_decryption_args += " " + GPG_DECRYPTION_COMMAND;
if (options.ContainsKey(COMMANDLINE_OPTIONS_PATH))
m_programpath = Library.Utility.Utility.ExpandEnvironmentVariables(options[COMMANDLINE_OPTIONS_PATH]);
}
#region IEncryption Members
public override string FilenameExtension { get { return "gpg"; } }
public override string Description { get { return Strings.GPGEncryption.Description; } }
public override string DisplayName { get { return Strings.GPGEncryption.DisplayName; } }
protected override void Dispose(bool disposing) { m_key = null; }
public override System.IO.Stream Encrypt(System.IO.Stream input)
{
return this.Execute(m_encryption_args, input, true);
}
public override System.IO.Stream Decrypt(System.IO.Stream input)
{
return this.Execute(m_decryption_args, input, false);
}
public override IList<ICommandLineArgument> SupportedCommands
{
get
{
return new List<ICommandLineArgument>(new ICommandLineArgument[] {
new CommandLineArgument(COMMANDLINE_OPTIONS_DISABLE_ARMOR, CommandLineArgument.ArgumentType.Boolean, Strings.GPGEncryption.GpgencryptiondisablearmorShort, Strings.GPGEncryption.GpgencryptiondisablearmorLong, "true", null, null, Strings.GPGEncryption.Gpgencryptiondisablearmordeprecated(COMMANDLINE_OPTIONS_ENABLE_ARMOR)),
new CommandLineArgument(COMMANDLINE_OPTIONS_ENABLE_ARMOR, CommandLineArgument.ArgumentType.Boolean, Strings.GPGEncryption.GpgencryptionenablearmorShort, Strings.GPGEncryption.GpgencryptionenablearmorLong, "false"),
new CommandLineArgument(COMMANDLINE_OPTIONS_ENCRYPTION_COMMAND , CommandLineArgument.ArgumentType.String, Strings.GPGEncryption.GpgencryptionencryptioncommandShort, Strings.GPGEncryption.GpgencryptionencryptioncommandLong(GPG_ENCRYPTION_COMMAND, "--encrypt"), GPG_ENCRYPTION_COMMAND),
new CommandLineArgument(COMMANDLINE_OPTIONS_DECRYPTION_COMMAND , CommandLineArgument.ArgumentType.String, Strings.GPGEncryption.GpgencryptiondecryptioncommandShort, Strings.GPGEncryption.GpgencryptiondecryptioncommandLong, GPG_DECRYPTION_COMMAND),
new CommandLineArgument(COMMANDLINE_OPTIONS_ENCRYPTION_OPTIONS , CommandLineArgument.ArgumentType.String, Strings.GPGEncryption.GpgencryptionencryptionswitchesShort, Strings.GPGEncryption.GpgencryptionencryptionswitchesLong, GPG_ENCRYPTION_DEFAULT_OPTIONS),
new CommandLineArgument(COMMANDLINE_OPTIONS_DECRYPTION_OPTIONS, CommandLineArgument.ArgumentType.String, Strings.GPGEncryption.GpgencryptiondecryptionswitchesShort, Strings.GPGEncryption.GpgencryptiondecryptionswitchesLong, GPG_DECRYPTION_DEFAULT_OPTIONS),
new CommandLineArgument(COMMANDLINE_OPTIONS_PATH, CommandLineArgument.ArgumentType.Path, Strings.GPGEncryption.GpgprogrampathShort, Strings.GPGEncryption.GpgprogrampathLong),
});
}
}
#endregion
/// <summary>
/// Internal helper that wraps GPG usage
/// </summary>
/// <param name="args">The commandline arguments</param>
/// <param name="input">The input stream</param>
/// <param name="output">The output stream</param>
private System.IO.Stream Execute(string args, System.IO.Stream input, bool encrypt)
{
System.Diagnostics.ProcessStartInfo psi = new System.Diagnostics.ProcessStartInfo();
psi.Arguments = args;
psi.CreateNoWindow = true;
psi.FileName = m_programpath;
psi.RedirectStandardError = true;
psi.RedirectStandardInput = true;
psi.RedirectStandardOutput = true;
psi.UseShellExecute = false;
psi.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
#if DEBUG
psi.CreateNoWindow = false;
psi.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal;
Console.Error.WriteLine(string.Format("Running command: \"{0}\" {1}", m_programpath, args));
#endif
System.Diagnostics.Process p;
try
{
p = System.Diagnostics.Process.Start(psi);
p.StandardInput.WriteLine(m_key);
p.StandardInput.Flush();
System.Threading.Thread.Sleep(1000);
if (p.HasExited)
throw new Exception(p.StandardError.ReadToEnd());
}
catch (Exception ex)
{
throw new Exception(Strings.GPGEncryption.GPGExecuteError(m_programpath, args, ex.Message), ex);
}
if (encrypt)
{
//Prevent blocking of the output buffer
System.Threading.Thread t = new System.Threading.Thread(new System.Threading.ParameterizedThreadStart(Runner));
t.Start(new object[] { p.StandardOutput.BaseStream, input });
return new GPGStreamWrapper(p, t, p.StandardInput.BaseStream);
}
else
{
//Prevent blocking of the input buffer
System.Threading.Thread t = new System.Threading.Thread(new System.Threading.ParameterizedThreadStart(Runner));
t.Start(new object[] { input, p.StandardInput.BaseStream });
return new GPGStreamWrapper(p, t, p.StandardOutput.BaseStream);
}
}
/// <summary>
/// Copies the content of one stream into another, invoked as a thread
/// </summary>
/// <param name="x">An array with two stream instances</param>
private void Runner(object x)
{
//Unwrap arguments and read stream
object[] tmp = (object[])x;
Utility.Utility.CopyStream((Stream)tmp[0], (Stream)tmp[1]);
((Stream)tmp[1]).Close();
}
}
}