/* Convert hex to base64
* The string:
* "49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d"
* Should produce:
* "SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t"
* So go ahead and make that happen. You'll need to use this code for the rest of the exercises.
* Cryptopals Rule
* Always operate on raw bytes, never on encoded strings. Only use hex and base64 for pretty-printing.
*/
public static void Set1Challenge1()
{
string input = "49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d";
string expect = "SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t";
string output = Convert.ToBase64String(BinaryOperations.HexToBytes(input));
Console.WriteLine("Set 1 Challenge 1: " + expect.ToUpper().Equals(output.ToUpper()));
Console.WriteLine("Set 1 Challenge 1: (input) " + Encoding.ASCII.GetString(BinaryOperations.HexToBytes(input)));
}
/* Single-byte XOR cipher
* The hex encoded string:
* "1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736"
* ... has been XOR'd against a single character. Find the key, decrypt the message.
* You can do this by hand. But don't: write code to do it for you.
* How? Devise some method for "scoring" a piece of English plaintext. Character frequency is a good metric. Evaluate each output and choose the one with the best score.
* Achievement Unlocked
* You now have our permission to make "ETAOIN SHRDLU" jokes on Twitter.
*/
public static void Set1Challenge3()
{
string str = "1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736";
List <byte[]> input = new List <byte[]>
{
BinaryOperations.HexToBytes(str)
};
string output = Crypto.SingleXorDecrypt(input)[0].Item2;
Console.WriteLine("Set 1 Challenge 3: " + output);
}
/* Fixed XOR
* Write a function that takes two equal-length buffers and produces their XOR combination.
* If your function works properly, then when you feed it the string:
* "1c0111001f010100061a024b53535009181c"
* ... after hex decoding, and when XOR'd against:
* "686974207468652062756c6c277320657965"
* ... should produce:
* "746865206b696420646f6e277420706c6179"
*/
public static void Set1Challenge2()
{
string input = "1c0111001f010100061a024b53535009181c";
string key = "686974207468652062756c6c277320657965";
string expect = "746865206b696420646f6e277420706c6179";
string output = BitConverter.ToString(BinaryOperations.Xor(BinaryOperations.HexToBytes(input), BinaryOperations.HexToBytes(key))).Replace("-", string.Empty);
Console.WriteLine("Set 1 Challenge 2: " + expect.ToUpper().Equals(output.ToUpper()));
Console.WriteLine("Set 1 Challenge 2: (key) " + Encoding.ASCII.GetString(BinaryOperations.HexToBytes(key)));
Console.WriteLine("Set 1 Challenge 2: (expect) " + Encoding.ASCII.GetString(BinaryOperations.HexToBytes(expect)));
}
/* Detect single-character XOR
* One of the 60-character strings in this file(@"../../set1challenge4.txt") has been encrypted by single-character XOR.
* Find it.
* (Your code from #3 should help.)
*/
public static void Set1Challenge4()
{
string[] lines = File.ReadAllLines(@"../../../data/set1/4.txt");
List <byte[]> input = new List <byte[]>();
foreach (string line in lines)
{
input.Add(BinaryOperations.HexToBytes(line));
}
string output = Crypto.SingleXorDecrypt(input)[0].Item2;
Console.WriteLine("Set 1 Challenge 4: " + output.Trim());
}
