Add TLS certificate checker

diff --git a/tls-check b/tls-check
new file mode 100644 (file)
index 0000000..d16e80a
--- /dev/null
+++ b/tls-check
@@ -0,0 +1,68 @@
+#!/usr/bin/python
+
+from __future__ import print_function
+from optparse import OptionParser
+from ssl import SSLContext, PROTOCOL_TLSv1_2, CERT_REQUIRED, cert_time_to_seconds, SSLError
+from socket import socket, AF_INET6
+from datetime import datetime, timedelta
+
+VERBOSE=False
+
+def check_cert(host, port, ca, warn, crit):
+    context = SSLContext(PROTOCOL_TLSv1_2)
+    context.verify_mode = CERT_REQUIRED
+    context.load_verify_locations(ca)
+    connection = context.wrap_socket(socket(AF_INET6),
+                                     server_hostname=host)
+    try:
+        connection.connect((host, port))
+    except SSLError:
+        print("CRIT (invalid certificate) %s:%d" % (host, port))
+        return 2
+        
+    expiretimestamp = cert_time_to_seconds(connection.getpeercert()['notAfter'])
+    delta = datetime.utcfromtimestamp(expiretimestamp) - datetime.utcnow()
+
+    if delta < crit:
+        print("CRIT (expires in %s) %s:%d" % (delta, host, port))
+        return 2
+    elif delta < warn:
+        print("WARN (expires in %s) %s:%d" % (delta, host, port))
+        return 1
+    
+
+def main():
+    global VERBOSE
+    parser = OptionParser()
+    parser.add_option("-n", "--name",
+                      action="append", type="string", dest="hosts",
+                      help="hostname:port to check for expired certificates")
+    parser.add_option("-w", "--warning-days",
+                      action="store", type=int, dest="warn", default=15,
+                      help="minimum remaining validity in days before a warning is issued")
+    parser.add_option("-c", "--critical-days",
+                      action="store", type=int, dest="crit", default=5,
+                      help="minimum remaining validity in days before a warning is issued")
+    parser.add_option("-v", action="store_true", dest="verbose", default=False)
+    parser.add_option("-q", action="store_false", dest="verbose")
+    parser.add_option("--ca", action="store", type="string", dest="ca",
+                      default="/etc/ssl/certs/ca-certificates.crt",
+                      help="ca certificate bundle")
+
+        
+    opts, _args = parser.parse_args()
+
+    VERBOSE = opts.verbose
+    if not opts.hosts:
+        parser.error("needs at least one host")
+
+    try:
+        hosts = [ (i[0], int(i[1])) for i in [ j.split(':', 1) for j in opts.hosts ] ]
+    except (ValueError, IndexError):
+        parser.error("names need to be in DNSNAME:PORT format")
+        
+    for host, port in hosts:
+        check_cert(host, port, opts.ca, timedelta(opts.warn), timedelta(opts.crit))
+                      
+if __name__ == "__main__":
+    main()