Use getpass instead of input function for password

SignalDesktopDecrypt.py

@@ -4,6 +4,7 @@ from Crypto.Cipher import AES
 from Crypto.Util import Padding
 from Crypto.Hash import HMAC, SHA256
 import sys
+from getpass import getpass
 IV_LENGTH = 16
 NONCE_LENGTH = 16
 MAC_LENGTH = 16
@@ -29,7 +30,7 @@ def generate_key(password):
 	return m.digest()
 
 def main():
-	password = input('Password: ')
+	password = getpass()
 	key = generate_key(password.encode('utf-8'))
 
 	# generate string to be pasted in Signal-Desktop