refactor: clean-up for pylint

.pylintrc

@@ -45,7 +45,7 @@ limit-inference-results=100
 
 # List of plugins (as comma separated values of python module names) to load,
 # usually to register additional checkers.
-load-plugins=pylint_django
+load-plugins=
 
 # Pickle collected data for later comparisons.
 persistent=yes

checkcert/checkcert.py

@@ -1,15 +1,14 @@
-# heavily modified version of https://gist.githubusercontent.com/gdamjan/55a8b9eec6cf7b771f92021d93b87b2c/raw/d8dc194ec4d0187f985a57138019d04e3a59b51f/ssl-check.py
-# to give a CLI for passing the hosts to check and other optional output
+""" CLI to get basic information about certificates and determine validity"""
+from collections import namedtuple
+import concurrent.futures
+from socket import socket
 import click
 from OpenSSL import SSL
 from OpenSSL import crypto
 from cryptography import x509
 from cryptography.x509.oid import NameOID
 import idna
-import sys
 
-from socket import socket
-from collections import namedtuple
 
 __version__ = "0.2.0"
 
@@ -19,10 +18,10 @@ HostInfo = namedtuple(
 
 
 def get_certificate(hostname, port):
+    """retreive certificate details and return HostInfo tuple of values"""
     hostname_idna = idna.encode(hostname)
     sock = socket()
 
-    try:
     sock.connect((hostname, port))
     peername = sock.getpeername()
     ctx = SSL.Context(SSL.SSLv23_METHOD)  # most compatible
@@ -36,8 +35,6 @@ def get_certificate(hostname, port):
     crypto_cert = cert.to_cryptography()
     sock_ssl.close()
     sock.close()
-    except ConnectionRefusedError:
-        pass
 
     return HostInfo(
         cert=crypto_cert,
@@ -48,6 +45,7 @@ def get_certificate(hostname, port):
 
 
 def get_alt_names(cert):
+    """retreive the SAN values for given cert"""
     try:
         ext = cert.extensions.get_extension_for_class(x509.SubjectAlternativeName)
         return ext.value.get_values_for_type(x509.DNSName)
@@ -56,10 +54,12 @@ def get_alt_names(cert):
 
 
 def get_x509_text(cert):
+    """return the human-readable text version of the certificate"""
     return crypto.dump_certificate(crypto.FILETYPE_TEXT, cert)
 
 
 def get_common_name(cert):
+    """Retrun the common name from the certificate"""
     try:
         names = cert.subject.get_attributes_for_oid(NameOID.COMMON_NAME)
         return names[0].value
@@ -68,6 +68,7 @@ def get_common_name(cert):
 
 
 def get_issuer(cert):
+    """Return the name of the CA/Issuer of the certificate"""
     try:
         names = cert.issuer.get_attributes_for_oid(NameOID.COMMON_NAME)
         return names[0].value
@@ -75,46 +76,40 @@ def get_issuer(cert):
         return None
 
 
-def print_basic_info(hostinfo):
-    print(
-        f"""
-{hostinfo.hostname} ({hostinfo.peername[0]}:{hostinfo.peername[1]})
-\tcommonName: {get_common_name(hostinfo.cert)}
-\tSAN: {get_alt_names(hostinfo.cert)}
-\tissuer: {get_issuer(hostinfo.cert)}
-\tnotBefore: {hostinfo.cert.not_valid_before}
-\tnotAfter:  {hostinfo.cert.not_valid_after}
-          """
-    )
-
-
 @click.command()
 @click.version_option(__version__, prog_name="checkcert")
 @click.option("--san", is_flag=True, help="Output Subject Alternate Names")
 @click.option(
     "--dump", is_flag=True, help="Dump the full text version of the x509 certificate"
 )
-@click.option("--color/--no-color", default=True)
+@click.option(
+    "--color/--no-color",
+    default=True,
+    help="Enable/disable ANSI color output to show cert validity",
+)
 @click.argument("hosts", nargs=-1)
 def main(san, dump, color, hosts):
+    """Return information about certificates given including their validity"""
     # setup the list of tuples
-    HOSTS = []
+    all_hosts = []
     # handle a domain given with a : in it to specify the port
     for host in hosts:
         # if  a host has a : in it, split on the :, first field will be host
         # second field will be the port
         if ":" in host:
             host_info = host.split(":")
-            HOSTS.append((host_info[0], int(host_info[1])))
+            all_hosts.append((host_info[0], int(host_info[1])))
         else:
-            HOSTS.append((host, 443))
-    for hostinfo in map(lambda x: get_certificate(x[0], x[1]), HOSTS):
+            all_hosts.append((host, 443))
+    with concurrent.futures.ThreadPoolExecutor(max_workers=4) as epool:
+        for hostinfo in epool.map(lambda x: get_certificate(x[0], x[1]), all_hosts):
             output_string = ""
             if dump:
                 print(get_x509_text(hostinfo.cert).decode())
             else:
                 output_string += (
-                f"{hostinfo.hostname} ({hostinfo.peername[0]}:{hostinfo.peername[1]})\n"
+                    f"{hostinfo.hostname} "
+                    f"({hostinfo.peername[0]}:{hostinfo.peername[1]})\n"
                 )
                 output_string += f"\tcommonName: {get_common_name(hostinfo.cert)}\n"
                 if san:
@@ -133,4 +128,4 @@ def main(san, dump, color, hosts):
 
 
 if __name__ == "__main__":
-    main()  # pragma: no cover
+    main()  # pylint: disable=no-value-for-parameter # pragma: no cover