added lab2 questions

IS/Lab/Lab2/aes_192.py

@@ -0,0 +1,29 @@
+from Crypto.Cipher import AES
+from Crypto.Util.Padding import pad, unpad
+
+def aes_cipher(key):
+    return AES.new(key.encode('utf-8'), AES.MODE_ECB)
+
+def aes_en(ptext, key):
+    cipher = aes_cipher(key)
+    ptext = pad(ptext.encode('utf-8'), AES.block_size)
+    return cipher.encrypt(ptext)
+
+def aes_de(ctext, key):
+    cipher = aes_cipher(key)
+    decrypted = cipher.decrypt(ctext)
+    return unpad(decrypted, AES.block_size).decode('utf-8')
+
+def aespad_key(key):
+        return key.ljust(24)[:24]
+
+def main():
+    ptext = input("Enter plaintext: ")
+    key = input("Enter key: ")
+    key = aespad_key(key)
+    ctext = aes_en(ptext, key)
+    print("Ciphertext:", ctext.hex())
+    print("Decrypted:", aes_de(ctext, key))
+
+if __name__ == '__main__':
+    main()