i think the test cases are done...

gpg/kant.py

@@ -1,12 +1,14 @@
 #!/usr/bin/env python3
 
 import argparse
+import datetime
 import email
 import os
 import re
-from io import BytesIO
 import subprocess
-import datetime
+from io import BytesIO
+from socket import *
+from urllib.parse import urlparse
 import gpgme  # non-stdlib; Arch package is "python-pygpgme"
 
 # TODO:
@@ -31,6 +33,32 @@ import gpgme  # non-stdlib; Arch package is "python-pygpgme"
 #
 #Thanks again!
 
+def serverParser(uri):
+    # https://en.wikipedia.org/wiki/Key_server_(cryptographic)#Keyserver_examples
+    # We need to make a mapping of the default ports.
+    server = {}
+    protos = {'hkp': [11371, ['tcp', 'udp']],
+              'hkps': [443, ['tcp']],  # Yes, same as https
+              'http': [80, ['tcp']],
+              'https': [443, ['tcp']],  # SSL/TLS
+              'ldap': [389, ['tcp', 'udp']],  # includes TLS negotiation since it runs on the same port
+              'ldaps': [636, ['tcp', 'udp']]}  # SSL
+    urlobj = urlparse(uri)
+    server['proto'] = urlobj.scheme
+    lazy = False
+    if not server['proto']:
+        server['proto'] = 'hkp'  # Default
+    server['server'] = urlobj.hostname
+    if not server['server']:
+        server['server'] = re.sub('^([A-Za-z]://)?(.+[^:][^0-9])(:[0-9]+)?$', '\g<2>', uri)
+        lazy = True
+    server['port'] = urlobj.port
+    if not server['port']:
+        if lazy:
+            p = re.sub('.*:([0-9]+)$', '\g<1>', uri)
+    server['port'] = protos[server['proto']]  # Default
+    return(server)
+
 def parseArgs():
     def getDefGPGDir():
         try:
@@ -97,7 +125,21 @@ def parseArgs():
                       '--keyservers',
                       dest = 'keyservers',
                       default = defkeyservers,
-                      help = 'The comma-separated keyserver(s) to push to. If "None", don\'t push signatures. Default is \033[1m{0}\033[0m.'.format(','.join(defkeyservers)))
+                      help = 'The comma-separated keyserver(s) to push to. If "None", don\'t push signatures. Default is \033[1m{0}\033[0m.'.format(
+                                                                                                        ','.join(
+                                                                                                                 defkeyservers)))
+    args.add_argument('-n',
+                      '--netproto',
+                      dest = 'netproto',
+                      action = 'store',
+                      choices = ['4', '6'],
+                      default = '4',
+                      help = 'Whether to use (IPv)4 or (IPv)6. Default is to use IPv4.')
+    args.add_argument('-t',
+                      '--testkeyservers',
+                      dest = 'testkeyservers',
+                      action = 'store_true',
+                      help = 'If specified, initiate a test connection with each keyserver before anything else. Disabled by default.')
     return(args)
 
 def verifyArgs(args):
@@ -107,6 +149,7 @@ def verifyArgs(args):
     #args['keyservers'] = [s.strip() for s in args['keyservers'].split(',')]
     args['keys'] = [re.sub('\s', '', k) for k in args['keys'].split(',')]
     args['keyservers'] = [re.sub('\s', '', s) for s in args['keyservers'].split(',')]
+    args['keyservers'] = [serverParser(s) for s in args['keyservers']]
     ## Key(s) to sign
     args['rcpts'] = {}
     for k in args['keys']:
@@ -145,15 +188,36 @@ def verifyArgs(args):
         if not sigkey.can_sign or True in (sigkey.revoked, sigkey.expired, sigkey.disabled):
             raise ValueError('{0} is not a valid candidate for signing'.format(args['sigkey']))
     ## Keyservers
-    # https://en.wikipedia.org/wiki/Key_server_(cryptographic)#Keyserver_examples
-    for s in args['keyservers']:
-        pass
+    if args['testkeyservers']:
+        for s in args['keyservers']:
+            # Test to make sure the keyserver is accessible.
+            # First we need to construct a way to use python's socket connector
+            # Great. Now we need to just quickly check to make sure it's accessible - if specified.
+            if args['netproto'] == '4':
+                nettype = AF_INET
+            elif args['netproto'] == '6':
+                nettype = AF_INET6
+            for proto in s['port'][1]:
+                if proto == 'udp':
+                    netproto = SOCK_DGRAM
+                elif proto == 'tcp':
+                    netproto = SOCK_STREAM
+                sock = socket(nettype, netproto)
+                sock.settimeout(10)
+                tests = sock.connect_ex((s['server'], int(s['port'][0])))
+                uristr = '{0}://{1}:{2} ({3})'.format(s['proto'], s['server'], s['port'][0], proto.upper())
+                if not tests == 0:
+                    raise RuntimeError('Keyserver {0} is not available'.format(uristr))
+                else:
+                    print('Keyserver {0} is accepting connections.'.format(uristr))
+                sock.close()
     return(args)
 
 def main():
     rawargs = parseArgs()
     args = verifyArgs(vars(rawargs.parse_args()))
-    print(args)
+    import pprint
+    pprint.pprint(args)
 
 if __name__ == '__main__':
     main()