Adding ssl-cert-check

1 files changed, 705 insertions, 0 deletions

diff --git a/files/ssl-cert-check b/files/ssl-cert-check
new file mode 100644
index 0000000..72de361
--- /dev/null
+++ b/files/ssl-cert-check
@@ -0,0 +1,705 @@
+#!/bin/bash
+#
+# Program: SSL Certificate Check <ssl-cert-check>
+#
+# Source code home: http://prefetch.net/code/ssl-cert-check
+#
+# Documentation: http://prefetch.net/articles/checkcertificate.html
+#
+# Author: Matty < matty91 at gmail dot com >
+#
+# Current Version: 3.21
+#
+# Revision History:
+
+# Version 3.21
+#   - Adjust e-mail checking to avoid exiting if notifications aren't enabled -- Nick Anderson
+#   - Added the number of days until expiration to the Nagios output -- Nick Anderson
+#
+# Version 3.20
+#   - Fixed a bug in certificate length checking -- Tim Nowaczyk
+#
+# Version 3.19
+#   - Added check to verify the certificate retrieved is valid
+#
+# Version 3.18
+#   - Add support for connecting to FTP servers -- Paul A Sand 
+#
+# Version 3.17
+#   - Add support for connecting to imap servers -- Joerg Pareigis
+#
+# Version 3.16
+#   - Add support for connecting to the mail sbmission port -- Luis E. Munoz
+#
+# Version 3.15
+#   - Adjusted the file checking logic to use the correct certificate -- Maciej Szudejko 
+#   - Add sbin to the default search paths for OpenBSD compatibility -- Alex Popov
+#   - Use cut instead of substring processing to ensure compatibility -- Alex Popov
+#
+# Version 3.14
+#   - Fixed the Common Name parser to handle DN's where the CN is not the last item 
+#     eg. EmailAddr -- Jason Brothers
+#   - Added the ability to grab the serial number -- Jason Brothers
+#   - Added the "-b" option to print results without a header -- Jason Brothers
+#   - Added the "-v" option for certificate validation -- Jason Brothers
+#
+# Version 3.13
+#   - Updated the subject line to include the hostname as well as
+#     the common name embedded in the X509 certificate (if it's
+#     available) -- idea proposed by Mike Burns 
+#
+#  Version 3.12
+#   - Updated the license to allow redistribution and modification
+#
+#  Version 3.11
+#   - Added ability to comment out lines in files passed
+#     to the "-f" option -- Brett Stauner
+#   - Fixed comment next to file processing logic
+#
+#  Version 3.10
+#   - Fixed POP3 port -- Simon Matter
+#
+#  Version 3.9
+#    - Switched binary location logic to use which utility
+#
+#  Version 3.8
+#    - Fixed display on 80 column displays
+#    - Cleaned up the formatting
+#
+#  Version 3.7
+#    - Fixed bug in NAGIOS tests -- Ben Allen 
+#
+#  Version 3.6
+#    - Added support for certificates stored in PKCS#12 databases -- Ken Gallo
+#    - Cleaned up comments
+#    - Adjusted variables to be more consistent
+#
+#  Version 3.5
+#    - Added support for NAGIOS -- Quanah Gibson-Mount
+#    - Added additional checks for mail -- Quanah Gibson-Mount
+#    - Convert tabs to spaces -- Quanah Gibson-Mount
+#    - Cleaned up usage() routine
+#    - Added additional checks for openssl
+#
+#  Version 3.4
+#   - Added a missing "{" to line 364 -- Ken Gallo
+#   - Move mktemp to the start of the main body to avoid errors
+#   - Adjusted default binary paths to make sure the script just works
+#     w/ Solaris, BSD and Linux hosts
+#
+#  Version 3.3
+#   - Added common name from X.509 certificate file to E-mail body / header -- Doug Curtis
+#   - Fixed several documentation errors 
+#   - Use mktemp to create temporary files
+#   - Convert printf, sed and awk to variables 
+#   - Check for printf, sed, awk and mktemp binaries
+#   - Add additional logic to make sure mktemp returned a valid temporary file
+#
+#  Version 3.2
+#   - Added option to list certificates in the file passed to "-f".
+#
+#  Version 3.1
+#   - Added handling for starttls for smtp -- Marco Amrein
+#   - Added handling for starttls for pop3 (without s) -- Marco Amrein
+#   - Removed extra spacing at end of script
+#
+#  Version 3.0
+#   - Added "-i" option to print certificate issuer  
+#   - Removed $0 from Subject line of outbound e-mails
+#   - Fixed some typographical errors
+#   - Removed redundant "-b" option
+#
+#  Version 2.0
+#    - Fixed an issue with e-mails formatting incorrectly
+#    - Added additional space to host column -- Darren-Perot Spruell
+#    - Replaced GNU date dependency with CHRIS F. A. JOHNSON's 
+#      date2julian shell function. This routine can be found on 
+#      page 170 of Chris's book "Shell Scripting Recipes: A 
+#      Problem-Solution Approach," ISBN #1590594711. Julian function 
+#      was created based on a post to comp.unix.shell by Tapani Tarvainen.
+#    - Cleaned up function descriptions
+#    - Removed several lines of redundant code
+#    - Adjusted the help message
+#      
+#   Version 1.1
+#    - Added "-c" flag to report expiration status of a PEM encoded 
+#      certificate -- Hampus Lundqvist
+#    - Updated the prints messages to display the reason a connection
+#      failed (connection refused, connection timeout, bad cert, etc)
+#    - Updated the GNU date checking routines
+#    - Added checks for each binary required
+#    - Added checks for connection timeouts
+#    - Added checks for GNU date
+#    - Added a "-h" option
+#    - Cleaned up the documentation
+#
+#  Version 1.0
+#      Initial Release
+#
+# Last Updated: 11-23-2010
+#
+# Purpose: 
+#  ssl-cert-check checks to see if a digital certificate in X.509 format
+#  has expired. ssl-cert-check can be run in interactive and batch mode,
+#  and provides facilities to alarm if a certificate is about to expire.
+#
+# License: 
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+#  GNU General Public License for more details.
+#
+# Requirements:
+#   Requires openssl
+# 
+# Installation: 
+#   Copy the shell script to a suitable location
+#
+# Tested platforms:
+#  -- Solaris 9 using /bin/bash
+#  -- Solaris 10 using /bin/bash
+#  -- OS X 10.4.2 using /bin/sh
+#  -- OpenBSD using /bin/sh
+#  -- FreeBSD using /bin/sh
+#  -- Redhat Enterprise Linux 3, 4, 5 & 6
+# 
+# Usage:
+#  Refer to the usage() sub-routine, or invoke ssl-cert-check 
+#  with the "-h" option.
+# 
+# Examples:
+#   Please refer to the following site for documentation and 
+#   examples:
+#      http://prefetch.net/articles/checkcertificate.html
+#
+
+PATH=/bin:/usr/bin:/sbin:/usr/sbin:/usr/local/bin:/usr/local/ssl/bin:/usr/sfw/bin
+export PATH
+
+# Who to page when an expired certificate is detected (cmdline: -e)
+ADMIN="root"
+
+# Number of days in the warning threshhold  (cmdline: -x)
+WARNDAYS=30
+
+# If QUIET is set to TRUE, don't print anything on the console (cmdline: -q)
+QUIET="FALSE"
+
+# Don't send E-mail by default (cmdline: -a)
+ALARM="FALSE"
+
+# Don't run as a Nagios plugin by default (cmdline: -n)
+NAGIOS="FALSE"
+
+# NULL out the PKCSDBPASSWD variable for later use (cmdline: -k)
+PKCSDBPASSWD=""
+
+# Location of system binaries
+AWK=$(which awk)
+DATE=$(which date)
+GREP=$(which grep)
+OPENSSL=$(which openssl)
+PRINTF=$(which printf)
+SED=$(which sed)
+MKTEMP=$(which mktemp)
+
+# Return code used by nagios. Initialize to 0.
+RETCODE=0
+
+# Set the default umask to be somewhat restrictive
+umask 077
+
+#############################################################################
+# Purpose: Convert a date from MONTH-DAY-YEAR to Julian format
+# Acknowledgements: Code was adapted from examples in the book
+#                   "Shell Scripting Recipes: A Problem-Solution Approach"
+#                   ( ISBN 1590594711 )
+# Arguments:
+#   $1 -> Month (e.g., 06)
+#   $2 -> Day   (e.g., 08)
+#   $3 -> Year  (e.g., 2006)
+#############################################################################
+date2julian() {
+
+    if [ "${1} != "" ] && [ "${2} != ""  ] && [ "${3}" != "" ]
+    then
+        ## Since leap years add aday at the end of February, 
+        ## calculations are done from 1 March 0000 (a fictional year)
+        d2j_tmpmonth=$((12 * ${3} + ${1} - 3))
+        
+        ## If it is not yet March, the year is changed to the previous year
+        d2j_tmpyear=$(( ${d2j_tmpmonth} / 12))
+        
+        ## The number of days from 1 March 0000 is calculated
+        ## and the number of days from 1 Jan. 4713BC is added 
+        echo $(( (734 * ${d2j_tmpmonth} + 15) / 24
+                 - 2 * ${d2j_tmpyear} + ${d2j_tmpyear}/4 
+                 - ${d2j_tmpyear}/100 + ${d2j_tmpyear}/400 + $2 + 1721119 ))
+    else
+        echo 0
+    fi
+}
+
+#############################################################################
+# Purpose: Convert a string month into an integer representation
+# Arguments:
+#   $1 -> Month name (e.g., Sep)
+#############################################################################
+getmonth() 
+{
+    case ${1} in
+        Jan) echo 1 ;;
+        Feb) echo 2 ;;
+        Mar) echo 3 ;;
+        Apr) echo 4 ;;
+        May) echo 5 ;;
+        Jun) echo 6 ;;
+        Jul) echo 7 ;;
+        Aug) echo 8 ;;
+        Sep) echo 9 ;;
+        Oct) echo 10 ;;
+        Nov) echo 11 ;;
+        Dec) echo 12 ;;
+          *) echo  0 ;;
+    esac
+}
+
+#############################################################################
+# Purpose: Calculate the number of seconds between two dates
+# Arguments:
+#   $1 -> Date #1
+#   $2 -> Date #2
+#############################################################################
+date_diff() 
+{
+    if [ "${1}" != "" ] &&  [ "${2}" != "" ]
+    then
+        echo $((${2} - ${1}))
+    else
+        echo 0
+    fi
+}
+
+#####################################################################
+# Purpose: Print a line with the expiraton interval
+# Arguments:
+#   $1 -> Hostname
+#   $2 -> TCP Port 
+#   $3 -> Status of certification (e.g., expired or valid)
+#   $4 -> Date when certificate will expire
+#   $5 -> Days left until the certificate will expire 
+#   $6 -> Issuer of the certificate
+#####################################################################
+prints() 
+{
+    if [ "${QUIET}" != "TRUE" ] && [ "${ISSUER}" = "TRUE" ] && [ "${VALIDATION}" != "TRUE" ]
+    then
+        MIN_DATE=$(echo $4 | ${AWK} '{ print $1, $2, $4 }')
+        if [ "${NAGIOS}" == "TRUE" ]
+        then
+            ${PRINTF} "%-35s %-17s %-8s %-11s %-4s %-30s\n" "$1:$2" "$6" "$3" "$MIN_DATE" \|days="$5" 
+        else
+            ${PRINTF} "%-35s %-17s %-8s %-11s %-4s %-30s\n" "$1:$2" "$6" "$3" "$MIN_DATE" "$5" 
+        fi
+    elif [ "${QUIET}" != "TRUE" ] && [ "${ISSUER}" = "TRUE" ] && [ "${VALIDATION}" == "TRUE" ]
+    then
+        ${PRINTF} "%-35s %-35s %-32s %-17s\n" "$1:$2" "$7" "$8" "$6"
+
+    elif [ "${QUIET}" != "TRUE" ] && [ "${VALIDATION}" != "TRUE" ]
+    then
+        MIN_DATE=$(echo $4 | ${AWK} '{ print $1, $2, $4 }')
+        if [ "${NAGIOS}" == "TRUE" ]
+        then
+            ${PRINTF} "%-47s %-12s %-12s %-4s %-30s\n" "$1:$2" "$3" "$MIN_DATE" \|days="$5" 
+        else
+            ${PRINTF} "%-47s %-12s %-12s %-4s %-30s\n" "$1:$2" "$3" "$MIN_DATE" "$5" 
+        fi  
+    elif [ "${QUIET}" != "TRUE" ] && [ "${VALIDATION}" == "TRUE" ]
+    then
+        ${PRINTF} "%-35s %-35s %-32s\n" "$1:$2" "$7" "$8"
+    fi
+}
+
+
+####################################################
+# Purpose: Print a heading with the relevant columns
+# Arguments:
+#   None
+####################################################
+print_heading() 
+{
+    if [ "${NOHEADER}" != "TRUE" ]
+    then 
+       if [ "${QUIET}" != "TRUE" ] && [ "${ISSUER}" = "TRUE" ] && [ "${NAGIOS}" != "TRUE" ] && [ "${VALIDATION}" != "TRUE" ]
+       then
+           ${PRINTF} "\n%-35s %-17s %-8s %-11s %-4s\n" "Host" "Issuer" "Status" "Expires" "Days"
+           echo "----------------------------------- ----------------- -------- ----------- ----"
+
+       elif [ "${QUIET}" != "TRUE" ] && [ "${ISSUER}" = "TRUE" ] && [ "${NAGIOS}" != "TRUE" ] && [ "${VALIDATION}" == "TRUE" ]
+       then
+           ${PRINTF} "\n%-35s %-35s %-32s %-17s\n" "Host" "Common Name" "Serial #" "Issuer"
+           echo "----------------------------------- ----------------------------------- -------------------------------- -----------------"
+    
+       elif [ "${QUIET}" != "TRUE" ] && [ "${NAGIOS}" != "TRUE" ] && [ "${VALIDATION}" != "TRUE" ]
+       then
+           ${PRINTF} "\n%-47s %-12s %-12s %-4s\n" "Host" "Status" "Expires" "Days" 
+           echo "----------------------------------------------- ------------ ------------ ----"
+    
+       elif [ "${QUIET}" != "TRUE" ] && [ "${NAGIOS}" != "TRUE" ] && [ "${VALIDATION}" == "TRUE" ]
+       then
+           ${PRINTF} "\n%-35s %-35s %-32s\n" "Host" "Common Name" "Serial #"
+           echo "----------------------------------- ----------------------------------- --------------------------------"
+        fi
+    fi
+}
+
+
+##########################################
+# Purpose: Describe how the script works
+# Arguments:
+#   None
+##########################################
+usage() 
+{
+    echo "Usage: $0 [ -e email address ] [ -x days ] [-q] [-a] [-b] [-h] [-i] [-n] [-v]"
+    echo "       { [ -s common_name ] && [ -p port] } || { [ -f cert_file ] } || { [ -c certificate file ] }" 
+    echo ""
+    echo "  -a                : Send a warning message through E-mail"
+    echo "  -b                : Will not print header"
+    echo "  -c cert file      : Print the expiration date for the PEM or PKCS12 formatted certificate in cert file"
+    echo "  -e E-mail address : E-mail address to send expiration notices"
+    echo "  -f cert file      : File with a list of FQDNs and ports"
+    echo "  -h                : Print this screen"
+    echo "  -i                : Print the issuer of the certificate"
+    echo "  -k password       : PKCS12 file password"
+    echo "  -n                : Run as a Nagios plugin"
+    echo "  -p port           : Port to connect to (interactive mode)"
+    echo "  -s commmon name   : Server to connect to (interactive mode)"
+    echo "  -q                : Don't print anything on the console"
+    echo "  -v                : Only print validation data"
+    echo "  -x days           : Certificate expiration interval (eg. if cert_date < days)"
+    echo ""
+}
+
+
+##########################################################################
+# Purpose: Connect to a server ($1) and port ($2) to see if a certificate
+#          has expired
+# Arguments:
+#   $1 -> Server name
+#   $2 -> TCP port to connect to
+##########################################################################
+check_server_status() {
+
+
+
+    if [ "_${2}" = "_smtp" -o "_${2}" = "_25" ]
+    then
+        TLSFLAG="-starttls smtp"
+
+    elif [ "_${2}" = "_ftp" -o "_${2}" = "_21" ]
+    then
+        TLSFLAG="-starttls ftp"
+
+    elif [ "_${2}" = "_pop3" -o "_${2}" = "_110" ]
+    then
+        TLSFLAG="-starttls pop3"
+    
+    elif [ "_${2}" = "_imap" -o "_${2}" = "_143" ]
+    then
+        TLSFLAG="-starttls imap"
+
+    elif [ "_${2}" = "_submission" -o "_${2}" = "_587" ]
+    then
+        TLSFLAG="-starttls smtp -port ${2}"
+    else
+        TLSFLAG=""
+    fi
+
+    echo "" | ${OPENSSL} s_client -connect ${1}:${2} ${TLSFLAG} 2> ${ERROR_TMP} 1> ${CERT_TMP}
+
+    if ${GREP} -i  "Connection refused" ${ERROR_TMP} > /dev/null
+    then
+        prints ${1} ${2} "Connection refused" "Unknown"  
+    
+    elif ${GREP} -i "gethostbyname failure" ${ERROR_TMP} > /dev/null
+    then
+        prints ${1} ${2} "Cannot resolve domain" "Unknown" 
+    
+    elif ${GREP} -i "Operation timed out" ${ERROR_TMP} > /dev/null
+    then
+        prints ${1} ${2} "Operation timed out" "Unknown"  
+ 
+    elif ${GREP} -i "ssl handshake failure" ${ERROR_TMP} > /dev/null
+    then
+        prints ${1} ${2} "SSL handshake failed" "Unknown"  
+
+    elif ${GREP} -i "connect: Connection timed out" ${ERROR_TMP} > /dev/null
+    then
+        prints ${1} ${2} "Connection timed out" "Unknown"  
+
+    else
+        check_file_status ${CERT_TMP} $1 $2
+    fi
+}
+
+#####################################################
+### Check the expiration status of a certificate file
+### Accepts three parameters:
+###  $1 -> certificate file to process
+###  $2 -> Server name
+###  $3 -> Port number of certificate
+#####################################################
+check_file_status() {
+
+    CERTFILE=${1}
+    HOST=${2}
+    PORT=${3}
+
+    ### Check to make sure the certificate file exists
+    if [ ! -r ${CERTFILE} ] || [ -z ${CERTFILE} ]
+    then
+        echo "ERROR: The file named ${CERTFILE} is unreadable or doesn't exist"
+        echo "ERROR: Please check to make sure the certificate for ${HOST}:${PORT} is valid"
+        RETCODE=1
+        return
+    fi
+      
+    ### Grab the expiration date from the X.509 certificate
+    if [ "${PKCSDBPASSWD}" != "" ]
+    then
+        # Extract the certificate from the PKCS#12 database, and
+        # send the informational message to /dev/null
+        ${OPENSSL} pkcs12 -nokeys -in ${CERTFILE} \
+                  -out ${CERT_TMP} -password pass:${PKCSDBPASSWD} 2> /dev/null
+           
+        # Extract the expiration date from the certificate
+        CERTDATE=$(${OPENSSL} x509 -in ${CERT_TMP} -enddate -noout | \
+                 ${SED} 's/notAfter\=//')
+
+        # Extract the issuer from the certificate
+        CERTISSUER=$(${OPENSSL} x509 -in ${CERT_TMP} -issuer -noout | \
+                    ${AWK} 'BEGIN {RS="/" } $0 ~ /^O=/ \
+                                  { print substr($0,3,17)}')
+
+        ### Grab the common name (CN) from the X.509 certificate
+        COMMONNAME=$(${OPENSSL} x509 -in ${CERT_TMP} -subject -noout | \
+                   ${SED} -e 's/.*CN=//' | \
+				   ${SED} -e 's/\/.*//')
+        
+	### Grab the serial number from the X.509 certificate
+        SERIAL=$(${OPENSSL} x509 -in ${CERT_TMP} -serial -noout | \
+                   ${SED} -e 's/serial=//')
+    else
+        # Extract the expiration date from the ceriticate
+        CERTDATE=$(${OPENSSL} x509 -in ${CERTFILE} -enddate -noout | \
+                 ${SED} 's/notAfter\=//')
+
+        # Extract the issuer from the certificate
+        CERTISSUER=$(${OPENSSL} x509 -in ${CERTFILE} -issuer -noout | \
+                   ${AWK} 'BEGIN {RS="/" } $0 ~ /^O=/ { print substr($0,3,17)}')
+
+        ### Grab the common name (CN) from the X.509 certificate
+        COMMONNAME=$(${OPENSSL} x509 -in ${CERTFILE} -subject -noout | \
+                   ${SED} -e 's/.*CN=//' | \
+				   ${SED} -e 's/\/.*//')
+	### Grab the serial number from the X.509 certificate
+        SERIAL=$(${OPENSSL} x509 -in ${CERTFILE} -serial -noout | \
+                   ${SED} -e 's/serial=//')
+    fi
+
+    ### Split the result into parameters, and pass the relevant pieces to date2julian
+    set -- ${CERTDATE}
+    MONTH=$(getmonth ${1})
+
+    # Convert the date to seconds, and get the diff between NOW and the expiration date
+    CERTJULIAN=$(date2julian ${MONTH#0} ${2#0} ${4})
+    CERTDIFF=$(date_diff ${NOWJULIAN} ${CERTJULIAN})
+
+    if [ ${CERTDIFF} -lt 0 ]
+    then
+        if [ "${ALARM}" = "TRUE" ]
+        then
+            echo "The SSL certificate for ${HOST} \"(CN: ${COMMONNAME})\" has expired!" \
+                 | ${MAIL} -s "Certificate for ${HOST} \"(CN: ${COMMONNAME})\" has expired!" ${ADMIN}
+        fi
+
+        prints ${HOST} ${PORT} "Expired" "${CERTDATE}" "${CERTDIFF}" "${CERTISSUER}" "${COMMONNAME}" "${SERIAL}"
+        RETCODE=2
+
+    elif [ ${CERTDIFF} -lt ${WARNDAYS} ]
+    then
+        if [ "${ALARM}" = "TRUE" ]
+        then
+            echo "The SSL certificate for ${HOST} \"(CN: ${COMMONNAME})\" will expire on ${CERTDATE}" \
+                 | ${MAIL} -s "Certificate for ${HOST} \"(CN: ${COMMONNAME})\" will expire in ${WARNDAYS}-days or less" ${ADMIN}
+        fi
+        prints ${HOST} ${PORT} "Expiring" "${CERTDATE}" "${CERTDIFF}" "${CERTISSUER}" "${COMMONNAME}" "${SERIAL}" 
+        RETCODE=1
+
+    else
+        prints ${HOST} ${PORT} "Valid" "${CERTDATE}" "${CERTDIFF}" "${CERTISSUER}" "${COMMONNAME}" "${SERIAL}"
+        RETCODE=0
+    fi
+}
+
+#################################
+### Start of main program
+#################################
+while getopts abinve:f:c:hk:p:s:qx: option
+do
+    case "${option}"
+    in
+        a) ALARM="TRUE";;
+        b) NOHEADER="TRUE";;
+        c) CERTFILE=${OPTARG};;
+        e) ADMIN=${OPTARG};;
+        f) SERVERFILE=$OPTARG;;
+        h) usage
+           exit 1;;
+        i) ISSUER="TRUE";;
+        k) PKCSDBPASSWD=${OPTARG};;
+        n) NAGIOS="TRUE";;
+        p) PORT=$OPTARG;;
+        s) HOST=$OPTARG;;
+        q) QUIET="TRUE";;
+        v) VALIDATION="TRUE";;
+        x) WARNDAYS=$OPTARG;;
+       \?) usage
+           exit 1;;
+    esac
+done
+
+if [ -f /usr/bin/mailx ]
+then
+    MAIL="/usr/bin/mailx"
+else
+    if [ "${ALARM}" == "FALSE" ]
+    then
+        MAIL=$(which mail 2>/dev/null)
+    else
+        MAIL=$(which mail)
+    fi
+fi
+
+
+### Check to make sure a openssl utility is available
+if [ ! -f ${OPENSSL} ]
+then
+    echo "ERROR: The openssl binary does not exist in ${OPENSSL}."
+    echo "FIX: Please modify the \${OPENSSL} variable in the program header."
+    exit 1
+fi
+
+### Check to make sure a date utility is available
+if [ ! -f ${DATE} ]
+then
+    echo "ERROR: The date binary does not exist in ${DATE} ."
+    echo "FIX: Please modify the \${DATE} variable in the program header."
+    exit 1
+fi
+
+### Check to make sure a grep utility is available
+if [ ! -f ${GREP} ]
+then
+    echo "ERROR: The grep binary does not exist in ${GREP} ."
+    echo "FIX: Please modify the \${GREP} variable in the program header."
+    exit 1
+fi
+
+### Check to make sure the mktemp and printf utilities are available
+if [ ! -f ${MKTEMP} ] || [ ! -f ${PRINTF} ]
+then
+    echo "ERROR: Unable to locate the mktemp or printf binary."
+    echo "FIX: Please modify the \${MKTEMP} and \${PRINTF} variables in the program header."
+    exit 1
+fi
+
+### Check to make sure the sed and awk binaries are available
+if [ ! -f ${SED} ] || [ ! -f ${AWK} ]
+then
+    echo "ERROR: Unable to locate the sed or awk binary."
+    echo "FIX: Please modify the \${SED} and \${AWK} variables in the program header."
+    exit 1
+fi
+
+### CHeck to make sure a mail client is available it automated notifcations are requested
+if [ "${ALARM}" = "TRUE" ] && [ ! -f ${MAIL} ]
+then
+    echo "ERROR: You enabled automated alerts, but the mail binary could not be found."
+    echo "FIX: Please modify the ${MAIL} variable in the program header."
+    exit 1
+fi
+
+# Place to stash temporary files
+CERT_TMP=$($MKTEMP  /var/tmp/cert.XXXXXX)
+ERROR_TMP=$($MKTEMP /var/tmp/error.XXXXXX)
+
+### Baseline the dates so we have something to compare to
+MONTH=$(${DATE} "+%m")
+DAY=$(${DATE} "+%d")
+YEAR=$(${DATE} "+%Y")
+NOWJULIAN=$(date2julian ${MONTH#0} ${DAY#0} ${YEAR})
+
+### Touch the files prior to using them
+if [ ! -z "${CERT_TMP}" ] && [ ! -z "${ERROR_TMP}" ]
+then
+    touch ${CERT_TMP} ${ERROR_TMP}
+else
+    echo "ERROR: Problem creating temporary files"
+    echo "FIX: Check that mktemp works on your system"
+    exit 1
+fi
+
+### If a HOST and PORT were passed on the cmdline, use those values
+if [ "${HOST}" != "" ] && [ "${PORT}" != "" ]
+then
+    print_heading
+    check_server_status "${HOST}" "${PORT}"
+
+### If a file is passed to the "-f" option on the command line, check 
+### each certificate or server / port combination in the file to see if 
+### they are about to expire
+elif [ -f "${SERVERFILE}" ]
+then
+    print_heading
+    while read HOST PORT
+    do
+        if [ "`echo ${HOST} | cut -c1`" = "#" ]
+        then
+            :
+        elif [ "$PORT" = "FILE" ]
+        then
+            check_file_status ${HOST} "FILE" "${HOST}"
+        else
+            check_server_status "${HOST}" "${PORT}"
+        fi
+
+    done < ${SERVERFILE}
+
+### Check to see if the certificate in CERTFILE is about to expire
+elif [ "${CERTFILE}" != "" ]
+then
+    print_heading
+    check_file_status ${CERTFILE} "FILE"  "${CERTFILE}"
+
+### There was an error, so print a detailed usage message and exit
+else
+    usage
+    exit 1
+fi
+
+### Remove the temporary files
+rm -f ${CERT_TMP} ${ERROR_TMP}
+
+### Exit with a success indicator
+if [ "${NAGIOS}" = "TRUE" ]; then
+    exit $RETCODE
+else
+    exit 0
+fi