SSL certificate name match monitor

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Author	jccleaver
Compatibility	Xymon 4.2.3
Requirements	perl, unix
Download	None
Last Update	2010-08-02

Description

Originating thread here: http://www.xymon.com/archive/2010/06/msg00148.html

A small script that checks “sslcert” tests and tries to verify that the common name (“CN=”) in the resulting ssl certificate matches the URL that we tried to reach (eg, https://secure.example.com/) It reports the status under a new test name, “sslname”. Wildcard certificates are taken into account, since we're matching using extended grep.

Client side

No change needed.

Server side

1. Copy the script into the ext/ directory (or wherever you're storing external scripts) and edit your tasks.cfg file by adding a new block:

# "sslname" runs the ssl certificate checker to verify that sslcert test results match
# the URL we tried to access
# 

[sslname]
        ENVFILE /etc/xymon/xymonserver.cfg
        NEEDS xymond
        CMD /etc/xymon/ext/sslname.sh
        LOGFILE /var/log/xymon/sslname.log

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sslname.sh

#!/bin/sh
 
# sslname.sh
# 
# Retrieve a list of all "sslcert" tests, which come out of any SSL-enabled
# check Xymon does using a built-in (probably https, but also things like imaps)
# 
# After getting this list, we go through each one looking for the common-
# name that the certificate responded with, verifying that it matched the
# url we were trying to reach in the originating test. Normally this means
# the address for the http test, but it could be just the hostname in the event
# of another SSL service.
# 
# Japheth Cleaver <jcleaver@soe.sony.com>
# No warranty. YMMV. Use at your own risk. This is not supported by my employer.
# 
 
 
# Set some defaults - I'm running this from hobbitlaunch, YMMV
 [ -z "$TESTNAME" ] 	&& TESTNAME=sslname
 [ -z "$BBDISP" ] 	&& BBDISP=0.0.0.0
 [ -z "$COLOR" ] 	&& COLOR="clear"
 [ -z "$BB" ] 		&& BB=/usr/bin/bb
 
 
# Get a list of all valid sslcert tests
 SSLHOSTS="`$BB $BBDISP \"hobbitdboard test=sslcert fields=hostname\"`"
 [ -z "$SSLHOSTS" ] && exit 0
 
 
# Loop over them and compare the common name with any URL we can find
 for THISHOST in $SSLHOSTS ; do
 
   # Return the details of this host's sslcert data, unescaping on the way
    SSLDATA="`$BB $BBDISP \"hobbitdboard host=^$THISHOST test=sslcert fields=hostname,msg\" | perl -pe 's/&gt;/>/g, s/&lt;/</g, s/&amp;/&/g;' -e 's/\\\n/\n/g;'`"
 
   # Find the common name...
    COMMONNAME="`echo \"$SSLDATA\" | grep CN= | perl -pe 's/^.*CN=([\w\.\-\*]+).*$/\1/'`"
    if [ -z "$COMMONNAME" ] ; then
	echo "Couldn't find a 'common name' for $THISHOST..." >&2
	continue
    fi
    # echo " -- Common name for $THISHOST is '$COMMONNAME'"
 
 
   # Isolate what hostname we were trying to access and store as URL,
   # if found. The HUMANURL is the full string, including any port number
    URL="`echo \"$SSLDATA\" | grep -c https://`"
    if [ $URL -eq 1 ] ; then
	# Great, a simple https address to look at
   	URL="`echo \"$SSLDATA\" | grep https:// | perl -pe 's#^.*https://([\w\.\-]+)(:\d+)?/.*$#\1#'`"
   	HUMANURL="`echo \"$SSLDATA\" | grep https:// | perl -pe 's#^.*(https://[\w\.\-]+(:\d+)?/).*$#\1#'`"
    else
	URL=$THISHOST
	HUMANURL=$THISHOST
    fi
 
 
   # Build our Xymon report
    if [ "`echo $URL | grep -cE $COMMONNAME`" -eq 1 ] ; then
	STATUS="SSL cert ok"
	COLOR="green"
	BODY="&green $HUMANURL matches certificate $COMMONNAME"
 
    else
	STATUS="SSL cert name MISMATCH"
	COLOR="red"
	BODY="&red $HUMANURL does NOT match certificate $COMMONNAME
 
<A HREF=\"$BBWEBHOST$BBSERVERCGIURL/bb-hostsvc.sh?HOST=$THISHOST&SERVICE=sslcert\">See 'sslcert' test results</A>"
 
    fi
 
   # Send results to Xymon
    THISCOMMA="`echo $THISHOST | sed -e 's/\./,/g'`"
    ## echo "$BODY" | $BB $BBDISP --both "status ${THISCOMMA}.${TESTNAME} ${COLOR} `date` - ${STATUS}"
    $BB $BBDISP "status ${THISCOMMA}.${TESTNAME} ${COLOR} `date` - ${STATUS}
$BODY"
 
done
 
 
# fin
exit 0