/// <summary>
/// Provede útok testováním všech dostupných klíčů
/// a následně vybere nejpravděpodobnější variantu.
/// </summary>
/// <param name="packet"></param>
/// <returns></returns>
public List<string> BruteForceAttack(string ciphertext, Storage.Languages language)
{
Dictionary<char, double> probability = new Dictionary<char, double>();
Caesar caesar = new Caesar();
string opentext;
Analyse.DoAlphabet(letter =>
{
opentext = caesar.Decrypt(ciphertext, letter.ToString());
probability[letter] = Analyse.SimilarityIndex(Analyse.NormalizeText(opentext, Analyse.TextTypes.WithoutSpacesLower), Storage.GetLangChar(language));
});
var resultPacket = probability.OrderBy(x => x.Value).ToArray()[0].Key;
return new List<string>() { resultPacket.ToString() };
}
public CaesarTest(Action progress, Action<string> afterFinish, Texts texts)
: base(progress, afterFinish, texts)
{
cipher = new Caesar();
}
private List<string> BruteForceAttack(string ciphertext, Storage.Languages language, int[] keysLength)
{
ciphertext = Analyse.NormalizeText(ciphertext, Analyse.TextTypes.WithoutSpacesLower);
Caesar caesar = new Caesar();
Dictionary<int, string> crackedKeys = new Dictionary<int, string>();
foreach(int keyLength in keysLength)
{
char[][] splitedChars = new char[keyLength][];
for (int i = 0; i < keyLength; i++)
splitedChars[i] = GetNthChars(ciphertext, keyLength, i);
char[] crackKeys = new char[keyLength];
for (int i = 0; i < keyLength; i++)
{
try
{
crackKeys[i] = caesar.Crack(Analyse.NormalizeText(new string(splitedChars[i]), Analyse.TextTypes.WithoutSpacesUpper), Caesar.TriangleID, language).First()[0];
}
catch (Exceptions.MatchNotFound)
{
crackKeys[i] = '?';
}
}
crackedKeys[keyLength] = new string(crackKeys);
}
var possKeys = crackedKeys.Where(x => x.Value.Length > 0).Select(x => x.Value).ToArray();
Dictionary<string, double> simIndexes = new Dictionary<string, double>();
for (int i = 0; i < possKeys.Length; i++)
{
string openttext = Decrypt(ciphertext, possKeys[i]);
double simIndex = Analyse.SimilarityIndex(openttext, Storage.GetLangChar(language));
simIndexes[possKeys[i]] = simIndex;
}
var result = simIndexes.OrderBy(x => x.Value).Select(x => x.Key).ToList();
return result;
}
