#51 crypto system

lockbox/cipher/mode/cfb.lua

@@ -0,0 +1,163 @@
+local Array = require("lockbox.util.array");
+local Stream = require("lockbox.util.stream");
+local Queue = require("lockbox.util.queue");
+
+local CFB = {};
+
+CFB.Cipher = function()
+
+    local public = {};
+
+    local key;
+    local blockCipher;
+    local padding;
+    local inputQueue;
+    local outputQueue;
+    local iv;
+
+    public.setKey = function(keyBytes)
+        key = keyBytes;
+        return public;
+    end
+
+    public.setBlockCipher = function(cipher)
+        blockCipher = cipher;
+        return public;
+    end
+
+    public.setPadding = function(paddingMode)
+        padding = paddingMode;
+        return public;
+    end
+
+    public.init = function()
+        inputQueue = Queue();
+        outputQueue = Queue();
+        iv = nil;
+        return public;
+    end
+
+    public.update = function(messageStream)
+        local byte = messageStream();
+        while (byte ~= nil) do
+            inputQueue.push(byte);
+            if(inputQueue.size() >= blockCipher.blockSize) then
+                local block = Array.readFromQueue(inputQueue, blockCipher.blockSize);
+
+                if(iv == nil) then
+                    iv = block;
+                else
+                    local out = iv;
+                    out = blockCipher.encrypt(key, out);
+                    out = Array.XOR(out, block);
+                    Array.writeToQueue(outputQueue, out);
+                    iv = out;
+                end
+            end
+            byte = messageStream();
+        end
+        return public;
+    end
+
+    public.finish = function()
+        local paddingStream = padding(blockCipher.blockSize, inputQueue.getHead());
+        public.update(paddingStream);
+
+        return public;
+    end
+
+    public.getOutputQueue = function()
+        return outputQueue;
+    end
+
+    public.asHex = function()
+        return Stream.toHex(outputQueue.pop);
+    end
+
+    public.asBytes = function()
+        return Stream.toArray(outputQueue.pop);
+    end
+
+    return public;
+
+end
+
+CFB.Decipher = function()
+
+    local public = {};
+
+    local key;
+    local blockCipher;
+    local padding;
+    local inputQueue;
+    local outputQueue;
+    local iv;
+
+    public.setKey = function(keyBytes)
+        key = keyBytes;
+        return public;
+    end
+
+    public.setBlockCipher = function(cipher)
+        blockCipher = cipher;
+        return public;
+    end
+
+    public.setPadding = function(paddingMode)
+        padding = paddingMode;
+        return public;
+    end
+
+    public.init = function()
+        inputQueue = Queue();
+        outputQueue = Queue();
+        iv = nil;
+        return public;
+    end
+
+    public.update = function(messageStream)
+        local byte = messageStream();
+        while (byte ~= nil) do
+            inputQueue.push(byte);
+            if(inputQueue.size() >= blockCipher.blockSize) then
+                local block = Array.readFromQueue(inputQueue, blockCipher.blockSize);
+
+                if(iv == nil) then
+                    iv = block;
+                else
+                    local out = iv;
+                    out = blockCipher.encrypt(key, out);
+                    out = Array.XOR(out, block);
+                    Array.writeToQueue(outputQueue, out);
+                    iv = block;
+                end
+            end
+            byte = messageStream();
+        end
+        return public;
+    end
+
+    public.finish = function()
+        local paddingStream = padding(blockCipher.blockSize, inputQueue.getHead());
+        public.update(paddingStream);
+
+        return public;
+    end
+
+    public.getOutputQueue = function()
+        return outputQueue;
+    end
+
+    public.asHex = function()
+        return Stream.toHex(outputQueue.pop);
+    end
+
+    public.asBytes = function()
+        return Stream.toArray(outputQueue.pop);
+    end
+
+    return public;
+
+end
+
+return CFB;