Implement encrypt, decrypt, perform_round

project.ipynb

@@ -24,150 +24,40 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "9\n"
-     ]
-    }
-   ],
-   "source": [
-    "sdes = SDES()\n",
-    "print(sdes.key_length)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "168\n",
-      "Almouhannad.Hafez + 1\n",
-      "True\n"
-     ]
-    }
-   ],
-   "source": [
-    "original_text = \"Almouhannad.Hafez + 1\"\n",
-    "bin = sdes.text_to_binary(original_text)\n",
-    "print(len(bin))\n",
-    "text = sdes.binary_to_text(bin)\n",
-    "print(text)\n",
-    "print(text == original_text)\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "['010000010110',\n",
-       " '110001101101',\n",
-       " '011011110111',\n",
-       " '010101101000',\n",
-       " '011000010110',\n",
-       " '111001101110',\n",
-       " '011000010110',\n",
-       " '010000101110',\n",
-       " '010010000110',\n",
-       " '000101100110',\n",
-       " '011001010111',\n",
-       " '101000100000',\n",
-       " '001010110010',\n",
-       " '000000110001']"
-      ]
-     },
-     "execution_count": 4,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "sdes.get_blocks(original_text)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "12434356\n"
-     ]
-    }
-   ],
-   "source": [
-    "print(sdes.E(\"123456\"))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "010\n"
-     ]
-    }
-   ],
-   "source": [
-    "print(sdes.apply_S(\"1101\", 2))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "011100100\n"
+      "key:\n",
+      " 00011100000101001110011110000000100100001000101011\n",
+      "original text:\n",
+      " Almouhannad.Hafez\n",
+      "original text in binary:\n",
+      " 010000010110110001101101011011110111010101101000011000010110111001101110011000010110010000101110010010000110000101100110011001010111101000000000\n",
+      "encrypted:\n",
+      " 000100001010000110100001100010010000111110100100111001011101001101010000111001011101111110001010110011010100101001110000110101001111100100110011\n",
+      "decrypted:\n",
+      " Almouhannad.Hafez\n"
      ]
     }
    ],
    "source": [
+    "sdes = SDES(\n",
+    "    key_length = 50,\n",
+    "    rounds_count = 100\n",
+    ")\n",
     "key = sdes.generate_random_key()\n",
-    "print(key)\n",
-    "##OK"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 31,
-   "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "000001111010\n"
-     ]
-    }
-   ],
-   "source": [
-    "block = \"111111000001\"\n",
-    "processed_block = sdes.process_block(key, 0, block)\n",
-    "print (processed_block)\n",
-    "##OK"
+    "print(f\"key:\\n {key}\")\n",
+    "text = \"Almouhannad.Hafez\"\n",
+    "print(f\"original text:\\n {text}\")\n",
+    "print(f\"original text in binary:\\n {sdes.text_to_binary(text)}\")\n",
+    "enc = sdes.encrypt(text, key)\n",
+    "print(f\"encrypted:\\n {enc}\")\n",
+    "dec = sdes.decrypt(enc, key)\n",
+    "print(f\"decrypted:\\n {dec}\")\n"
    ]
   }
  ],

s_des.py

@@ -150,35 +150,68 @@ class SDES:
         
         return text
     
-    def get_blocks(self, plain_text: str) -> list[str]:
+    def get_blocks(self, input: str) -> list[str]:
         """
-        Convert plain text into a list of binary strings, each with length of self.block_size
+        Convert input into a list of binary strings, each with length of self.block_size
 
         Parameters:
-            plain_text (str): Text to be converted
+            input (str): Input to be converted into blocks
 
         Returns:
-            blocks (list[str]): Binary blocks of the original text
+            blocks (list[str]): Binary blocks of the original input
         """
         # Type checking
-        if not isinstance(plain_text, str):
-            raise TypeError(f"'plain_text' must be str, got {type(plain_text).__name__}")
+        if not isinstance(input, str):
+            raise TypeError(f"'input' must be str, got {type(input).__name__}")
 
         # Validation rules
-        if len(plain_text) == 0:
-            raise ValueError("'plain_text' must not be empty")
+        if len(input) == 0:
+            raise ValueError("'input' must not be empty")
                 
-        binary_text = self.text_to_binary(plain_text)
         blocks = []
-        blocks = [binary_text[i:i+self.block_size] for i in range(0, len(binary_text), self.block_size)]
+        blocks = [input[i:i+self.block_size] for i in range(0, len(input), self.block_size)]
         return blocks
     
-###############################################################################################    
+###############################################################################################
+
+    def encrypt(self, plain_text: str, key: str) -> str:
+        binary_text = self.text_to_binary(plain_text)
+        output = binary_text
+        for i in range(self.rounds_count):
+            output = self.perform_round(i, key, output, 'enc')
+        return output
     
-    def process_block(self, key: str, round_number: int, old_block: str) -> str:
+    def decrypt(self, binary_encrypted_input: str, key: str) -> str:
+        output = binary_encrypted_input
+        for i in range(self.rounds_count):
+            output = self.perform_round(i, key, output, 'dec')
+        decrypted_plain_text = self.binary_to_text(output)
+        return decrypted_plain_text
+    
+    def perform_round (self, round_number: int, key: int, input: str, mode: str) -> str:
+        blocks = self.get_blocks(input)
+        if mode == 'dec':
+            round_number_inv = (self.rounds_count - round_number - 1) % self.rounds_count
+            round_key = self.get_round_key(key, round_number_inv)
+        else:
+            round_key = self.get_round_key(key, round_number)
+
+        output = ''
+        for i in range(len(blocks)):
+            blocks[i] = self.process_block(round_key, blocks[i])
+            if round_number == self.rounds_count -1:
+                block = blocks[i]
+                blocks[i] = ''
+                blocks[i] += block[self.block_size//2 : self.block_size]
+                blocks[i] += block[0:self.block_size//2]
+            output += blocks[i]
+        return output
+        
+
+
+    def process_block(self, round_key: str, old_block: str) -> str:
         L_old, R_old = old_block[0:self.block_size//2] , old_block[self.block_size//2 : self.block_size]
         L_new = R_old
-        round_key = self.get_round_key(key, round_number)
         R_new = self.f(round_key, R_old)
         R_new = self.binary_strings_xor(R_new, L_old)
         new_block = ''