/*
* The key for nihilist cipher has 2 components: the key for the polybius square, and the key for encryption, split by the character ~.
* If either one has characters not contained by the polybius square, the string is invalid.
*/
protected override CipherKey CheckKeyValidity(String key)
{
CipherKey cipherKey = new CipherKey();
String polybiusSquareKey, encryptionKey;
String[] temp = key.Split('~');
if (temp.Length != 2)
{
throw new InvalidKeyFormatException("The key introduced for the nihilist cipher doesn't respect the input format: {polybius square key}~{encryption key}");
}
polybiusSquareKey = temp[0];
encryptionKey = temp[1];
for (int i = 0; i < polybiusSquareKey.Length; i++)
{
if (!MyPolybiusSquare.ContainsCharacter(polybiusSquareKey[i]))
{
throw new InvalidKeyFormatException("The key introduced for the nihilist cipher for the polybius square contains more than the permitted characters!");
}
}
for (int i = 0; i < encryptionKey.Length; i++)
{
if (!MyPolybiusSquare.ContainsCharacter(encryptionKey[i]))
{
throw new InvalidKeyFormatException("The key introduced for the nihilist cipher for encryption contains more than alphabet letters!");
}
}
cipherKey.SetStringValue(encryptionKey);
return(cipherKey);
}
/*
* Checks if the string is only formed of an integer, otherwise throws an exception.
*/
protected override CipherKey CheckKeyValidity(String key)
{
CipherKey cipherKey = new CipherKey();
if (key.Equals("") || !int.TryParse(key, out int tempKey))
{
throw new InvalidKeyFormatException("The key introduced for the caesar cipher is not an integer!");
}
cipherKey.SetNumericalValue(tempKey % 26);
return(cipherKey);
}
/*
* Checks if the key string contains characters contained by the polybius square.
*/
protected override CipherKey CheckKeyValidity(String key)
{
CipherKey cipherKey = new CipherKey();
for (int i = 0; i < key.Length; i++)
{
if (!MyPolybiusSquare.ContainsCharacter(key[i]))
{
throw new InvalidKeyFormatException("The key introduced for the bifid cipher contains more than the permitted characters!");
}
}
cipherKey.SetStringValue(key);
return(cipherKey);
}