public void EnsureAgentResponsive()
{
// In certain situations, gpg-agent may hang and become unresponsive to input.
// This will cause any decryption attempts to hang indefinitely, without any indication of what's happening.
// Since that's obviously not desirable, we need to check whether the gpg-agent is still responsive, and if not, kill and restart it.
if (processes.GetProcessesByName(GpgAgentProcessName).Length == 0)
{
// If gpg-agent isn't running yet, it obviously can't be unresponsive, so we don't have to do anything here.
return;
}
if (!gpgInstallation.GpgConnectAgentExecutable.Exists)
{
Log.Send($"Unable to confirm that gpg-agent is alive. No connect-agent found at \"{gpgInstallation.GpgConnectAgentExecutable.FullName}\".", LogLevel.Warning);
return;
}
IProcess proc;
try
{
// We have a gpg-agent, let's see if we can connect to it.
proc = processes.Start(new ProcessStartInfo
{
FileName = gpgInstallation.GpgConnectAgentExecutable.FullName,
Arguments = "/bye",
UseShellExecute = false,
RedirectStandardOutput = true,
RedirectStandardError = true,
CreateNoWindow = true,
});
}
catch (Exception e)
{
Log.Send($"Unable to launch connect-agent process ({e.GetType().Name}: {e.Message})", LogLevel.Warning);
return;
}
// Now check what the process returns.
var readTask = proc.StandardError.ReadLineAsync();
// Give gpg-connect-agent a moment to see if it produces any output.
if (readTask.Wait(agentConnectTimeout))
{
if (readTask.Result == null)
{
// Nothing was sent through stdout, which means we successfully connected to a running agent,
// which means the agent is still responsive, so we won't have to do anything here.
Log.Send("gpg-agent alive.");
return;
}
else if (readTask.Result.Contains("waiting for agent"))
{
Log.Send("waiting for agent to respond...");
}
else if (readTask.Result.Contains("no running gpg-agent"))
{
Log.Send("gpg-agent is not running, waiting for it to start...");
}
else
{
Log.Send($"gpg-agent produced unexpected output: \"{readTask.Result}\"", LogLevel.Warning);
Log.Send($"waiting for agent to respond...");
}
// Now wait for gpg-connect-agent to quit, indicating that gpg-agent is running and responsive.
if (proc.WaitForExit(agentReadyTimeout))
{
Log.Send("gpg-agent ready.");
return;
}
Log.Send($"gpg-agent failed to start/respond within {agentReadyTimeout.TotalSeconds:F} seconds, starting a new one", LogLevel.Warning);
}
else
{
Log.Send($"gpg-connect-agent failed to produce any output within {agentConnectTimeout.TotalSeconds:F} seconds", LogLevel.Warning);
}
Log.Send($"gpg-agent is most likely unresponsive and will be restarted", LogLevel.Warning);
// First, kill the connect-agent process.
proc.Kill();
// Now try to find the correct gpg-agent process.
// We'll start by looking for a process whose filename matches the installation directory we're working with.
// This means that if there are several gpg-agents running, we will ignore those that our gpg process likely won't try to connect to.
var matches = processes.GetProcesses().Where(p => p.MainModuleName == gpgInstallation.GpgAgentExecutable.FullName).ToList();
if (matches.Any())
{
Log.Send($"Agent process(es) found (\"{gpgInstallation.InstallDirectory.FullName}\")");
// This should normally only return one match at most, but in certain cases
// GPG seems to be able to detect that the agent has become unresponsive,
// and will start a new one without killing the old process.
foreach (var match in matches)
{
Log.Send($" > killing gpg-agent {match.Id} (started {match.StartTime:G}), path: \"{match.MainModuleName}\"");
match.Kill();
}
}
else
{
// We didn't find any direct matches, so let's widen our search.
foreach (var match in processes.GetProcessesByName(GpgAgentProcessName))
{
Log.Send($" > killing gpg-agent {match.Id} (started {match.StartTime:G}), path: \"{match.MainModuleName}\"");
match.Kill();
}
}
}