lib/gamnit: intro draw_mode

[nit.git] / lib / crypto.nit

diff --git a/lib/crypto.nit b/lib/crypto.nit
index 011347d..2abe5d7 100644 (file)
--- a/lib/crypto.nit
+++ b/lib/crypto.nit
@@ -42,7 +42,7 @@ redef class Char
        end
 end
 
-redef class String
+redef class Text
        # Performs a Rotation of `x` on each letter of self
        #
        # Works by replacing every character in `self` by its
@@ -65,7 +65,7 @@ redef class String
        #
        # NOTE : Works on letters only
        # NOTE : This cipher is symmetrically decrypted with an `x` of 26-`x`
-       fun rot(x: Int): String do
+       fun rot(x: Int): Text do
                var rot = x % 26
                if rot < 0 then rot += 26
                var d = new FlatBuffer.with_capacity(length)
@@ -93,7 +93,7 @@ redef class String
        # Therefore, yielding the ciphertext : "fgounbmtcieehkh"
        #
        #     assert "fuckingbehemoth".railfence(4) == "fgounbmtcieehkh"
-       fun railfence(depth: Int): String do
+       fun railfence(depth: Int): Text do
                var lines = new Array[FlatBuffer].with_capacity(depth)
                var up = false
                for i in [0..depth[ do
@@ -127,10 +127,10 @@ redef class String
                return r.to_s
        end
 
-       # Transforms a rail-fence-encrypted String to its original
+       # Transforms a rail-fence-encrypted Text to its original
        #
        #     assert "fgounbmtcieehkh".unrail(4) == "fuckingbehemoth"
-       fun unrail(depth: Int): String do
+       fun unrail(depth: Int): Text do
                var dots = "." * length
                var arr = new FlatBuffer.from(dots)
                var start = 0
@@ -156,6 +156,24 @@ redef class String
        end
 end
 
+redef class Bytes
+
+       # Returns `self` xored with `key`
+       #
+       # The key is cycled through until the `self` has been completely xored.
+       #
+       #     assert "goodmorning".to_bytes.xorcipher(" ".to_bytes) == "GOODMORNING".bytes
+       fun xorcipher(key: Bytes): Bytes do
+               var xored = new Bytes.with_capacity(self.length)
+
+               for i in self.length.times do
+                       xored.add(self[i] ^ key[i % key.length])
+               end
+
+               return xored
+       end
+end
+
 redef class Int
        # Generates the paces for each depth.
        #
@@ -188,7 +206,7 @@ redef class Int
        #
        # In the end, our string is read using the generated array
        #
-       # SEE: `String::unrail` for how the array is used
+       # SEE: `Text::unrail` for how the array is used
        private fun unrail_paces: Array[Couple[Int, Int]] do
                var ret = new Array[Couple[Int,Int]].with_capacity(self)
                var extremes = new Couple[Int, Int]((self - 1) * 2, (self - 1) * 2)