Applied Cryptography Final Project Added

Anirudh/README.txt

@@ -0,0 +1,2 @@
+Terminal Chat App is a program which implements asymmetric encryption and decryption along with hashing under the hood.
+This program simulates real world processes of key sharing, hashing, symmetric encryption-decryption etc.

Anirudh/Terminal Chat App/Program Design

@@ -0,0 +1,74 @@
+Program Design ->
+
+    I. Person Class ->
+        A. Object Variables
+            1. Friend list
+            2. Private key
+            3. Public key
+            3. Secured symmetric keys / iv for all friends (list)
+            4. List of received messages
+            5. List of sent messages
+            6. Initialize person in global MESSAGES
+        B. Object Methods
+            1. Send message
+            2. Check message
+                a. Involves sending key and receiving key
+                b. Initialize personal messages list in global MESSAGES
+                c. Initialize person in sent and received messages
+            4. Send key
+            5. Receive key
+            6. Delete Friend
+        C. Static Variables
+            1. Public key list
+
+    II.User Functions ->
+        A.  Add Person
+            1. Generate Private Key and Public Key
+            2. Initializing friend list
+            3. Adding Public Key to Person Class
+            4. Add a new log in the terminal
+        B. Secure Channel
+            1. Generate a new session key
+            2. Use asymmetric encryption to share and receive key
+            3. Add secure symmetric key to each persons list (Secure key/iv list)
+            4. Add each other to respective friend lists
+        C. Send Message
+            1. Send message
+            2. Add to respective sent and received messages
+            3. Print appropriate messages on both terminal logs
+            4. Add Message to global MESSAGES as receiver -> sender -> messages[]
+            5. Send Hashed Message for verification
+        D. Check messages
+            1. Return recent messages
+            2. Checks if hash of decrypted message matches the hash sent
+            3. Clear old messages
+
+    III. Crypt Class ->
+        1. Contains all Functionality of the symmetric encryptor
+            decryptor encapsulated
+        2. Contains all implementation of padding
+        3. Contains Asymmetric encryption functionality for key sharing
+        4. Secure Channel
+            a. Sends key from sender to receiver
+            b. receives key from sender and decrypts and verifies
+
+    IV. String Class ->
+        1. Add spaces and remove spaces methods
+
+    V. Help menu (Explains commands) ->
+        1. Add new person using 'add <name>' command
+        2. To Enter into a specific user use 'select <name>' command
+        3. Go to help menu using 'help' command
+        4. List all users using 'list' command
+        5. Exit the application using 'exit' command
+
+        Enter any key to exit this menu
+
+    VI. Help menu (Explains user commands) ->
+        1. Add Friend using 'friend <name>' command
+        2. Add multiple friends using 'friend <name1> <name2> <name3> ... <nameN>' command
+        3. Check messages using 'check' command
+        4. To send a message to a friend use 'send <name> <message>' command
+        5. To delete a friend use 'delete <friend>' command
+        6. To go back to main menu using 'main_menu' command
+        7. Go to help menu using 'help' command

Anirudh/Terminal Chat App/Reference files/Alice.py

@@ -0,0 +1,17 @@
+import os
+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+from cryptography.hazmat.backends import default_backend
+backend = default_backend()
+key = os.urandom(32)
+iv = os.urandom(16)
+cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=backend)
+message= "a secret messageabc".encode()
+encryptor = cipher.encryptor()
+ct = encryptor.update(message) + encryptor.finalize()
+
+#decryptor = cipher.decryptor()
+#decryptor.update(ct) + decryptor.finalize()
+print(key)
+print(iv)
+print(message)
+print(ct)

Anirudh/Terminal Chat App/Reference files/AliceGenerate.py

@@ -0,0 +1,21 @@
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives.asymmetric import rsa
+from cryptography.hazmat.primitives import serialization
+backend=default_backend()
+
+
+private_key = rsa.generate_private_key(public_exponent=65537, key_size=2048, backend=backend)
+public_key = private_key.public_key()
+pemprivate = private_key.private_bytes(
+encoding=serialization.Encoding.PEM,
+format=serialization.PrivateFormat.PKCS8,
+encryption_algorithm=serialization.NoEncryption()
+)
+pempublic = public_key.public_bytes(
+encoding=serialization.Encoding.PEM,
+format=serialization.PublicFormat.SubjectPublicKeyInfo
+)
+
+print("Alice")
+print(pemprivate)
+print(pempublic)