nrpe[31528]: Error: Could not complete SSL handshake. 1

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simonl
Posts: 14
Joined: Tue Sep 24, 2013 8:38 pm

nrpe[31528]: Error: Could not complete SSL handshake. 1

Post by simonl »

I know this has been discussed but can't figure out my issue from previous discussions.
Running Red Hat Enterprise Linux Server release 6.3 (Santiago) on client.
Getting the following from /var/log/messages on this client server:

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Sep 25 14:36:27 dayrhencvp104 nrpe[31466]: Starting up daemon
Sep 25 14:36:27 dayrhencvp104 nrpe[31466]: Warning: Daemon is configured to accept command arguments from clients!
Sep 25 14:36:27 dayrhencvp104 nrpe[31466]: Listening for connections on port 5666
Sep 25 14:36:27 dayrhencvp104 nrpe[31466]: Allowing connections from: 127.0.0.1,10.7.33.59
Sep 25 14:36:55 dayrhencvp104 nrpe[31472]: Error: Could not complete SSL handshake. 1

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selinux is disabled

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-bash-4.1$ sudo service iptables status
iptables: Firewall is not running.

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-bash-4.1$ ps -ef|grep nrpe
nrpe     31466     1  0 14:36 ?        00:00:00 /usr/sbin/nrpe -c /etc/nagios/nrpe.cfg -d

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-bash-4.1$ cat /etc/nagios/nrpe.cfg
#############################################################################
# Sample NRPE Config File
# Written by: Ethan Galstad (nagios@nagios.org)
#
# Last Modified: 11-23-2007
#
# NOTES:
# This is a sample configuration file for the NRPE daemon.  It needs to be
# located on the remote host that is running the NRPE daemon, not the host
# from which the check_nrpe client is being executed.
#############################################################################


# LOG FACILITY
# The syslog facility that should be used for logging purposes.

log_facility=daemon



# PID FILE
# The name of the file in which the NRPE daemon should write it's process ID
# number.  The file is only written if the NRPE daemon is started by the root
# user and is running in standalone mode.

pid_file=/var/run/nrpe/nrpe.pid



# PORT NUMBER
# Port number we should wait for connections on.
# NOTE: This must be a non-priviledged port (i.e. > 1024).
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

server_port=5666



# SERVER ADDRESS
# Address that nrpe should bind to in case there are more than one interface
# and you do not want nrpe to bind on all interfaces.
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

#server_address=127.0.0.1



# NRPE USER
# This determines the effective user that the NRPE daemon should run as.
# You can either supply a username or a UID.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

nrpe_user=nrpe



# NRPE GROUP
# This determines the effective group that the NRPE daemon should run as.
# You can either supply a group name or a GID.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

nrpe_group=nrpe



# ALLOWED HOST ADDRESSES
# This is an optional comma-delimited list of IP address or hostnames
# that are allowed to talk to the NRPE daemon. Network addresses with a bit mask
# (i.e. 192.168.1.0/24) are also supported. Hostname wildcards are not currently
# supported.
#
# Note: The daemon only does rudimentary checking of the client's IP
# address.  I would highly recommend adding entries in your /etc/hosts.allow
# file to allow only the specified host to connect to the port
# you are running this daemon on.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

allowed_hosts=127.0.0.1,10.7.33.59



# COMMAND ARGUMENT PROCESSING
# This option determines whether or not the NRPE daemon will allow clients
# to specify arguments to commands that are executed.  This option only works
# if the daemon was configured with the --enable-command-args configure script
# option.
#
# *** ENABLING THIS OPTION IS A SECURITY RISK! ***
# Read the SECURITY file for information on some of the security implications
# of enabling this variable.
#
# Values: 0=do not allow arguments, 1=allow command arguments

dont_blame_nrpe=1



# BASH COMMAND SUBTITUTION
# This option determines whether or not the NRPE daemon will allow clients
# to specify arguments that contain bash command substitutions of the form
# $(...).  This option only works if the daemon was configured with both
# the --enable-command-args and --enable-bash-command-substitution configure
# script options.
#
# *** ENABLING THIS OPTION IS A HIGH SECURITY RISK! ***
# Read the SECURITY file for information on some of the security implications
# of enabling this variable.
#
# Values: 0=do not allow bash command substitutions,
#         1=allow bash command substitutions

allow_bash_command_substitution=0



# COMMAND PREFIX
# This option allows you to prefix all commands with a user-defined string.
# A space is automatically added between the specified prefix string and the
# command line from the command definition.
#
# *** THIS EXAMPLE MAY POSE A POTENTIAL SECURITY RISK, SO USE WITH CAUTION! ***
# Usage scenario:
# Execute restricted commmands using sudo.  For this to work, you need to add
# the nagios user to your /etc/sudoers.  An example entry for alllowing
# execution of the plugins from might be:
#
# nagios          ALL=(ALL) NOPASSWD: /usr/lib/nagios/plugins/
#
# This lets the nagios user run all commands in that directory (and only them)
# without asking for a password.  If you do this, make sure you don't give
# random users write access to that directory or its contents!

# command_prefix=/usr/bin/sudo



# DEBUGGING OPTION
# This option determines whether or not debugging messages are logged to the
# syslog facility.
# Values: 0=debugging off, 1=debugging on

debug=1



# COMMAND TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# allow plugins to finish executing before killing them off.

command_timeout=60



# CONNECTION TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# wait for a connection to be established before exiting. This is sometimes
# seen where a network problem stops the SSL being established even though
# all network sessions are connected. This causes the nrpe daemons to
# accumulate, eating system resources. Do not set this too low.

connection_timeout=300



# WEEK RANDOM SEED OPTION
# This directive allows you to use SSL even if your system does not have
# a /dev/random or /dev/urandom (on purpose or because the necessary patches
# were not applied). The random number generator will be seeded from a file
# which is either a file pointed to by the environment valiable $RANDFILE
# or $HOME/.rnd. If neither exists, the pseudo random number generator will
# be initialized and a warning will be issued.
# Values: 0=only seed from /dev/[u]random, 1=also seed from weak randomness

#allow_weak_random_seed=1



# INCLUDE CONFIG FILE
# This directive allows you to include definitions from an external config file.

#include=<somefile.cfg>



# INCLUDE CONFIG DIRECTORY
# This directive allows you to include definitions from config files (with a
# .cfg extension) in one or more directories (with recursion).

include_dir=/etc/nrpe.d/



# COMMAND DEFINITIONS
# Command definitions that this daemon will run.  Definitions
# are in the following format:
#
# command[<command_name>]=<command_line>
#
# When the daemon receives a request to return the results of <command_name>
# it will execute the command specified by the <command_line> argument.
#
# Unlike Nagios, the command line cannot contain macros - it must be
# typed exactly as it should be executed.
#
# Note: Any plugins that are used in the command lines must reside
# on the machine that this daemon is running on!  The examples below
# assume that you have plugins installed in a /usr/local/nagios/libexec
# directory.  Also note that you will have to modify the definitions below
# to match the argument format the plugins expect.  Remember, these are
# examples only!


# The following examples use hardcoded command arguments...

command[check_users]=/usr/lib64/nagios/plugins/check_users -w 5 -c 10
command[check_load]=/usr/lib64/nagios/plugins/check_load -w 15,10,5 -c 30,25,20
command[check_hda1]=/usr/lib64/nagios/plugins/check_disk -w 20% -c 10% -p /dev/hda1
command[check_zombie_procs]=/usr/lib64/nagios/plugins/check_procs -w 5 -c 10 -s Z
command[check_total_procs]=/usr/lib64/nagios/plugins/check_procs -w 150 -c 200


# The following examples allow user-supplied arguments and can
# only be used if the NRPE daemon was compiled with support for
# command arguments *AND* the dont_blame_nrpe directive in this
# config file is set to '1'.  This poses a potential security risk, so
# make sure you read the SECURITY file before doing this.

#command[check_users]=/usr/lib64/nagios/plugins/check_users -w $ARG1$ -c $ARG2$
#command[check_load]=/usr/lib64/nagios/plugins/check_load -w $ARG1$ -c $ARG2$
#command[check_disk]=/usr/lib64/nagios/plugins/check_disk -w $ARG1$ -c $ARG2$ -p $ARG3$
#command[check_procs]=/usr/lib64/nagios/plugins/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$
abrist
Red Shirt
Posts: 8334
Joined: Thu Nov 15, 2012 1:20 pm

Re: nrpe[31528]: Error: Could not complete SSL handshake. 1

Post by abrist »

Follow the steps in the document below to potentially resolve this issue:
http://assets.nagios.com/downloads/nagi ... utions.pdf
Specifically section III.
Former Nagios employee
"It is turtles. All. The. Way. Down. . . .and maybe an elephant or two."
VI VI VI - The editor of the Beast!
Come to the Dark Side.
simonl
Posts: 14
Joined: Tue Sep 24, 2013 8:38 pm

Re: nrpe[31528]: Error: Could not complete SSL handshake. 1

Post by simonl »

Document states:
Understand that if you installed from a corporate build or from a package repo, you may have either uninstall the current NRPE
package and install from source or pursue support on the specific distribution's forums or through Nagios support.


We did install the nrpe from a redhat repo. Do you have any insight on how to troubleshoot further
knowing it was installed from the RHEL repo using yum and not building it from the source?
abrist
Red Shirt
Posts: 8334
Joined: Thu Nov 15, 2012 1:20 pm

Re: nrpe[31528]: Error: Could not complete SSL handshake. 1

Post by abrist »

simonl wrote:Do you have any insight on how to troubleshoot further
knowing it was installed from the RHEL repo using yum and not building it from the source?
I am unsure if the repo properly configures nrpe, and whether or not it uses xinetd daemon. What is the output of:

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grep only_from /etc/xinetd.d/nrpe
grep allowed_hosts /usr/local/nagios/etc/nrpe.cfg
Former Nagios employee
"It is turtles. All. The. Way. Down. . . .and maybe an elephant or two."
VI VI VI - The editor of the Beast!
Come to the Dark Side.
simonl
Posts: 14
Joined: Tue Sep 24, 2013 8:38 pm

Re: nrpe[31528]: Error: Could not complete SSL handshake. 1

Post by simonl »

not using the xinetd, using
sudo service nrpe restart

grep of allowed hosts is:
allowed_hosts=127.0.0.1,10.7.33.59

thanks for your help
abrist
Red Shirt
Posts: 8334
Joined: Thu Nov 15, 2012 1:20 pm

Re: nrpe[31528]: Error: Could not complete SSL handshake. 1

Post by abrist »

Maybe the repo version of nrpe was not built with ssl support. Try running the following from the nagios server:

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/usr/local/nagios/libexec/check_nrpe -H <remote host ip> -n
If it works, then it was compiled without ssl support (disable ssl with -n).
Additionally, lets check to make sure the port is open. On the nagios server:

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nmap <ip of remote host> -p 5666
Former Nagios employee
"It is turtles. All. The. Way. Down. . . .and maybe an elephant or two."
VI VI VI - The editor of the Beast!
Come to the Dark Side.
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