Script for substitution cipher added

Author: namrun

port_scanner.py

@@ -0,0 +1,44 @@
+import pyfiglet 
+import sys 
+import socket 
+from datetime import datetime 
+   
+ascii_banner = pyfiglet.figlet_format("PORT SCANNER") 
+print(ascii_banner) 
+   
+# Defining a target 
+if len(sys.argv) == 2: 
+      
+    # translate hostname to IPv4 
+    target = socket.gethostbyname(sys.argv[1])  
+else: 
+    print("Invalid ammount of Argument") 
+  
+# Add Banner  
+print("-" * 50) 
+print("Scanning Target: " + target) 
+print("Scanning started at:" + str(datetime.now())) 
+print("-" * 50) 
+   
+try: 
+      
+    # will scan ports between 1 to 65,535 
+    for port in range(1,65535): 
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
+        socket.setdefaulttimeout(1) 
+          
+        # returns an error indicator 
+        result = s.connect_ex((target,port)) 
+        if result ==0: 
+            print("Port {} is open".format(port)) 
+        s.close() 
+          
+except KeyboardInterrupt: 
+        print("\n Exitting Program !!!!") 
+        sys.exit() 
+except socket.gaierror: 
+        print("\n Hostname Could Not Be Resolved !!!!") 
+        sys.exit() 
+except socket.error: 
+        print("\ Server not responding !!!!") 
+        sys.exit()

substitution_cipher.py

@@ -0,0 +1,35 @@
+#This script implements Substitution Cipher
+#The key for encrypting the message must be passed as a Command line argument in the form of a csv file
+
+#To run the script from terminal, run
+#python3 substitution_cipher.py "path_to_csv_file_containing_the_key"
+
+import csv
+import sys
+
+def get_key():
+    key = dict()
+    with open(sys.argv[1] , 'r') as file:
+        reader = csv.reader(file)
+        for row in reader:
+            key[row[0].strip()] = row[1].strip()
+    return(key)
+
+def encrypt():
+    key = get_key()
+    message = input("Enter the message ")
+    encrypted_message = ''
+    for letter in message:
+        try:
+            encrypted_message += key[letter]
+        except:
+            alert = "Your key does not have a suitable match for " + letter +  "\nPlease update your key and try again!" 
+            return(-1, alert)
+    return(0, encrypted_message)
+
+if __name__ == "__main__":
+    exit_code, message = encrypt()
+    if (exit_code == 0):
+        print("The encrypted message is " , message)
+    else:
+        print(message)