private Task <string> StartDecryptionAsync(string hash, int maxTextLength, string chars, CancellationToken token)
{
var hashDecryption = _runningDecryptions.GetOrAdd(hash, _ => new HashDecryption());
return(hashDecryption.GetOrAdd(maxTextLength, chars, async _ =>
{
using var linkedCts = hashDecryption.CreateLinkedTokenSource(token);
Func <Task <string> > decryption = async() =>
{
try
{
var text = await DesDecryptor.DecryptAsync(hash, maxTextLength, chars, linkedCts.Token);
_runningDecryptions.TryRemove(hash, out var _);
_logger.LogInformation($"Decryption of the {nameof(hash)} '{hash}' with " +
$"{nameof(maxTextLength)} = {maxTextLength} and {nameof(chars)} = '{chars}' succeeded. " +
$"The {nameof(hash)} '{hash}' corresponds to '{text}'.");
return text;
}
catch (OperationCanceledException)
{
if (_cache.TryGetValue(hash, out string text))
{
_logger.LogInformation($"Another task successfully decrypted " +
$"the {nameof(hash)} '{hash}' and it corresponds to '{text}'.");
return text;
}
throw;
}
finally
{
hashDecryption.TryRemove(maxTextLength, chars, out var _);
}
};
var text = await _cache.GetOrCreateAsync(hash, async cacheEntry =>
{
var text = await decryption();
cacheEntry.Size = text.Length;
return text;
});
hashDecryption.CancelAll();
return text;
}));
}
static async Task <int> Main(string[] args)
{
if (args.Length != 1)
{
Console.WriteLine("Usage: ./crack hash\n");
return(1);
}
try
{
Console.WriteLine($"{await DesDecryptor.DecryptAsync(args[0], MaxWordLength, Chars)}\n");
return(0);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
return(1);
}