Merge pull request #845 from Blandes22/Update-Password-Generator

Update password generator

Author: pawangeek

password_generator/password_generator.py

@@ -1,6 +1,6 @@
 import argparse  # to work with the arguments
 import string
-import random
+import secrets
 
 
 # function to generate the password
@@ -15,26 +15,26 @@ def get_password(length: int) -> str:
     password = ''
 
     # adding one symbol
-    password += random.choice(symbols)
+    password += secrets.choice(symbols)
 
     # adding one number
-    password += random.choice(numbers)
+    password += secrets.choice(numbers)
 
     # adding one lowercase character
-    password += random.choice(lowercase_characters)
+    password += secrets.choice(lowercase_characters)
 
     # adding one uppercase character
-    password += random.choice(uppercase_characters)
+    password += secrets.choice(uppercase_characters)
 
     # now run a for loop starting from the current length of the password
     # all the way to the maxium length to fill in the remaining data
     while len(password) < length:
         # adding all the data together into a one list
-        characters = list(lowercase_characters) + list(uppercase_characters)
-        data = symbols + numbers + characters
+        characters = lowercase_characters + uppercase_characters
+        data = symbols + numbers + list(characters)
 
         # getting a random character from the list
-        random_char = random.choice(data)
+        random_char = secrets.choice(data)
 
         # if asked to exclude duplicates
         if args.excludeduplicates:
@@ -46,24 +46,39 @@ def get_password(length: int) -> str:
             # then just add the character without checking
             password += random_char
 
-    # shuffling the generated password to mix every character
-    # creating a list of the password
+    # create a list of the password
     password_list = list(password)
-    random.shuffle(password_list)  # shuffling the list
+    # shuffle the list into random sequence
+    password = shuffle(password_list)
 
     # returning the password
-    return ''.join(password_list)
-
+    return password
+
+
+# shuffle function based on Fisher–Yates shuffle using secrets.choice()
+# as the integer selector
+def shuffle(password: list):
+    # n used to determine range of loop
+    n = len(password)
+    for x in range(n - 1, 0, -1):
+        # set new variable y to random int within needed index
+        y = secrets.choice(range(0, x + 1))
+        # swap elements at index x and index y
+        password[x], password[y] = password[y], password[x]
+    # return concatenated password
+    return ''.join(password)
 
 # main method
+
+
 def main(args: argparse.Namespace) -> None:
     # storing the length in a variable
     length = args.length
 
     # if the value is out of range then inform the user and exit
-    if length < 6 or length > 20:
-        print('ERROR: -l/--length should be in the range of 6 - 20')
-        exit(0)
+    # if length < 6 or length > 20:
+    #   print('ERROR: -l/--length should be in the range of 6 - 20')
+    #  exit(0)
 
     # this will hold the final password
     password = get_password(length)