From 380661cc64439e73f1beabdffddea11a7e33992d Mon Sep 17 00:00:00 2001
From: +++ <berhsi@web.de>
Date: Fri, 4 Sep 2020 19:58:23 +0200
Subject: [PATCH] cert-check added, fix typo

---
 setstatus.py | 80 +++++++++++++++++++++++++++++-----------------------
 1 file changed, 45 insertions(+), 35 deletions(-)

diff --git a/setstatus.py b/setstatus.py
index 107a8ea..aa1c1c7 100755
--- a/setstatus.py
+++ b/setstatus.py
@@ -12,6 +12,7 @@
 # krautspace door status. If no status is given as argument, he reads from
 # stdin until input is 0 or 1.
 
+import os
 import ssl
 import socket
 import logging
@@ -19,6 +20,18 @@ import configparser
 from sys import exit, argv
 
 
+
+def check_certs(certs):
+    '''
+    Check if certs readable.
+    '''
+    logging.debug('Check certificates')
+    for certfile in certs:
+        if os.access(certfile, os.R_OK) is False:
+            logging.error('Failed to read certificate: {}'.format(certfile))
+            return False
+    return True
+
 def check_arguments(argv):
     '''
     Checks length and validity of command line argument vectors. If there is
@@ -38,23 +51,7 @@ def check_arguments(argv):
             byte_value = None
     return byte_value
 
-
-def read_argument():
-    '''
-    Reads from stdin until the given value is valid. Convert the given
-    string to a byte value and return this value.
-    return: byte value
-    '''
-    status = None
-
-    while status is None:
-        buf = input('Enter new status (0/1): ')
-        if buf == '0' or buf == '1':
-            status = bytes([int(buf)])
-            logging.debug('Read status: {}'.format(status))
-    return status
-
-def print_config(config):
+def log_config(config):
     '''
     Logs the config with level debug.
     '''
@@ -70,7 +67,8 @@ def main():
     STATUS = None
     RESPONSE = None
 
-    loglevel = logging.DEBUG
+    # basic configuration
+    loglevel = logging.WARNING
     formatstring = '%(asctime)s: %(levelname)s: %(message)s'
     logging.basicConfig(format=formatstring, level=loglevel)
 
@@ -82,14 +80,15 @@ def main():
         'server': {
             'host': 'localhost',
             'port': 10001,
-            'cert': './certs/server.crt',
-            'fqdn': 'server.status.kraut.space'
+            'cert': './certs/server-pub.pem',
+            'fqdn': 'kraut.space'
         },
         'client': {
-            'cert': './certs/client.crt',
-            'key': './certs/client.key'
+            'cert': './certs/client-pub.pem',
+            'key': './certs/client-key.pem'
         }
     }
+    # read config file
     configfile = './setstatus.conf'
     config = configparser.ConfigParser()
     config.read_dict(default_config)
@@ -97,32 +96,43 @@ def main():
         logging.warning('Configuration file {} not found or not readable.'.format(
                         configfile))
         logging.warning('Using default values.')
-
+    # set loglevel
     logger = logging.getLogger()
-    if not config['general']['loglevel'] in ('critical', 'error', 'warning',
-                                             'info', 'debug'):
+    if not config['general']['loglevel'].lower() in ('critical', 'error',
+                                                     'warning', 'info',
+                                                     'debug'):
         logging.warning('Invalid loglevel %s given. Using default level %s.',
                         config['general']['loglevel'],
                         default_config['general']['loglevel'])
         config.set('general', 'loglevel', default_config['general']['loglevel'])
-
     logger.setLevel(config['general']['loglevel'].upper())
+    # log config if level is debug
+    if config['general']['loglevel'].lower() == 'debug':
+        log_config(config)
 
-    print_config(config)
+    # check certificates are readable
+    certs = (config['server']['cert'],
+             config['client']['cert'],
+             config['client']['key'])
+    if check_certs(certs) is False:
+        sys.exit(1)
 
+    # check cli arguments
     STATUS = check_arguments(argv)
-    while STATUS is None:
-        STATUS = read_argument()
+    if STATUS is None:
+        logging.error('No valid status given')
+        sys.exit(2)
 
+    # create ssl context
     context = ssl.create_default_context(ssl.Purpose.SERVER_AUTH,
                                          cafile=config['server']['cert'])
-    # use only cyphers for tls version 1.2 and 1.3
-    context.set_ciphers('EECDH+AESGCM')
+    context.set_ciphers('EECDH+AESGCM') # only ciphers for tls 1.2 and 1.3
     context.options |= getattr(ssl._ssl, 'OP_NO_COMPRESSION', 0)
     context.load_cert_chain(certfile=config['client']['cert'],
                             keyfile=config['client']['key'])
     logging.debug('SSL context created')
 
+    # create socket and send status bit
     with socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0) as mySocket:
         logging.debug('Socket created')
         try:
@@ -138,10 +148,10 @@ def main():
         try:
             conn.connect((config['server']['host'], int(config['server']['port'])))
         except socket.timeout:
-            logging.eror('Connection timeout')
+            logging.error('Connection timeout')
         except Exception as e:
             logging.error('Connection failed: {}'.format(e))
-            exit(1)
+            exit(3)
         logging.debug('Peer certificate commonName: {}'.format(
                       conn.getpeercert()['subject'][5][0][1]))
         logging.debug('Peer certificate serialNumber: {}'.format(
@@ -151,7 +161,7 @@ def main():
             conn.send(STATUS)
         except Exception as e:
             logging.error('Error: {}'.format(e))
-            exit(2)
+            exit(4)
         try:
             RESPONSE = conn.recv(1)
             logging.debug('Server returns: {}'.format(RESPONSE))
@@ -162,7 +172,7 @@ def main():
             logging.debug('Disconnect from server')
         except Exception as e:
             logging.error('Error: {}'.format(e))
-            exit(3)
+            exit(5)
 
 
 if __name__ == '__main__':