1 files changed, 90 insertions, 0 deletions

diff --git a/client/client.py b/client/client.py
new file mode 100755
index 0000000..abbc9de
--- /dev/null
+++ b/client/client.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+
+import socket
+import time
+import argparse
+import sys
+
+HEADER_LENGTH = 64
+KEY_LENGTH = 64
+DISCONNECT_LENGTH = ACK_LENGTH = 3
+ACK_MESSAGE = "ACK"
+DISCONNECT_MESSAGE = "BYE"
+FORMAT = "utf-8"
+
+def parse_arguments():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--server",type=str,help="IP of MFA Server",required=True)
+    parser.add_argument("--port",type=int,help="Port to connect to",required=True)
+    parser.add_argument("--key",type=str,help="Client connection key",required=True)
+    return parser.parse_args()
+
+def prompt_user(prompt):
+    # Prompt user for input and return input
+    print(prompt)
+    result = input("> ")
+    return result
+
+
+def init_connection(mfa_server, client_port, client_key):
+    # Attempts to connect to MFA server with provided address,port, and key.
+    # Repeats attempt once a seconds until timeout is reached.
+    # Returns socket or None if unable to connect
+    connection = None
+    timeout = 0
+    timeout_length = 5
+    sleep_length = 1
+    while connection == None and timeout < timeout_length:
+        try:
+            connection = socket.create_connection((mfa_server,client_port))
+            connection.send(client_key.encode(FORMAT))
+            response = connection.recv(ACK_LENGTH).decode(FORMAT)
+            if response == ACK_MESSAGE:
+                print("connected to mfa server")
+            elif response == DISCONNECT_MESSAGE:
+                print("server terminated connection")
+                sys.exit(1)
+        except ConnectionError:
+            time.sleep(sleep_length)
+            timeout += sleep_length
+    return connection
+
+
+def main():
+    # Get arguments, exit if unable to connect
+    args = parse_arguments()
+    mfa_server = args.server
+    client_port = args.port
+    client_key = args.key
+
+    # Exit if invalid key is provided
+    if len(client_key) != KEY_LENGTH:
+        print("invalid key")
+        sys.exit(1)
+
+    # Open connection to server
+    conn = init_connection(mfa_server,client_port,client_key)
+    if conn == None:
+        print("timed out attempting to connect to server")
+        sys.exit(1)
+
+    # Main loop
+    running = True
+    while running:
+        # Receive MFA prompt from server
+        prompt_len = int(conn.recv(HEADER_LENGTH).decode(FORMAT))
+        prompt = conn.recv(prompt_len).decode(FORMAT)
+        # Ask user for response
+        answer = prompt_user(prompt)
+        # Send answer to MFA server
+        answer_length = len(answer)
+        length_msg = str(answer_length)
+        length_msg += ' ' * (HEADER_LENGTH - len(length_msg))
+        conn.send(length_msg.encode(FORMAT))
+        conn.send(answer.encode(FORMAT))
+
+
+
+
+if __name__ == '__main__':
+    main()