Logstash to parse Local files,apache/niginx Logs

Filters in logstach 
Filters are an in-line processing mechanism which provide the flexibility to slice and dice your data to fit your needs. Let’s see one in action, namely the grok filter.

input { stdin { } }

filter {
  grok {
    match => { "message" => "%{COMBINEDAPACHELOG}" }
  }
  date {
    match => [ "timestamp" , "dd/MMM/yyyy:HH:mm:ss Z" ]
  }
}

output {
  elasticsearch { host => localhost }
  stdout { codec => rubydebug }
}
Run logstash with this configuration:

bin/logstash -f logstash-filter.conf
Now paste this line into the terminal (so it will be processed by the stdin input):

127.0.0.1 - - [11/Dec/2013:00:01:45 -0800] "GET /xampp/status.php HTTP/1.1" 200 3891 "http://cadenza/xampp/navi.php" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:25.0) Gecko/20100101 Firefox/25.0"


Run Logstash from Local File buy configuring input session. Below we parse a apache access log from local server. 

input {
  file {
    path => "/Users/kurt/logs/access_log"
    start_position => beginning
  }
}

filter {
  if [path] =~ "access" {
    mutate { replace => { "type" => "apache_access" } }
    grok {
      match => { "message" => "%{COMBINEDAPACHELOG}" }
    }
  }
  date {
    match => [ "timestamp" , "dd/MMM/yyyy:HH:mm:ss Z" ]
  }
}

output {
  elasticsearch {
    host => localhost
  }
  stdout { codec => rubydebug }
}

Logstach Configuration for parsing nginx Logs 

input {
  file {
    path => "/Users/kurt/logs/access_log"
    start_position => beginning
  }
}

filter {
  if [path] =~ "access" {
    mutate { replace => { "type" => "apache_access" } }
    grok {
      match => { "message" => "%{COMBINEDAPACHELOG}" }
    }
  }
  date {
    match => [ "timestamp" , "dd/MMM/yyyy:HH:mm:ss Z" ]
  }
}

output {
  elasticsearch {
    host => localhost
  }
  stdout { codec => rubydebug }
}

Log Monitoring WIth Kibana+Logstash+elasticsearch

Centralized logging using Logstash and elasticsearch  can be very useful when attempting to identify problems with your servers or applications, as it allows you to search through all of your logs in a single place.

Installing Java 

yum install java-1.7.0-openjdk-*

Install Elasticsearch

yum install https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-1.3.4.noarch.rpm

Elasticsearch is now installed. Let's edit the configuration:/etc/elasticsearch/elasticsearch.yml

Add the following line somewhere in the file, to disable dynamic scripts:

script.disable_dynamic: true

You will also want to restrict outside access to your Elasticsearch instance, so outsiders can't read your data or shutdown your Elasticseach cluster through the HTTP API. Find the line that specifies network.host and uncomment it so it looks like this:

network.host: localhost

Then disable multicast by finding the discovery.zen.ping.multicast.enabled item and uncommenting so it looks like this:

discovery.zen.ping.multicast.enabled: false


Now start Elasticsearch:

sudo service elasticsearch restart


Install Nginx

yum install -y http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

yum install nginx -y

Download the sample Nginx configuration from Kibana's github repository to your home directory:

cd ~; curl -OL https://gist.githubusercontent.com/thisismitch/2205786838a6a5d61f55/raw/f91e06198a7c455925f6e3099e3ea7c186d0b263/nginx.conf

Open the sample configuration file for editing:

vi nginx.conf

Find and change the values of the server_name to your FQDN (or localhost if you aren't using a domain name) and root to where we installed Kibana, so they look like the following entries:

server_name FQDN;
root  /usr/share/nginx/kibana3;

Save and exit. Now copy it over your Nginx default server block with the following command:

sudo cp ~/nginx.conf /etc/nginx/conf.d/default.conf


Installing Kibana to parse the logs
wget https://download.elasticsearch.org/kibana/kibana/kibana-3.1.1.tar.gz
tar zxvf kibana-3.1.1.tar.gz


Open the Kibana configuration file kibana-3.1.1/config.js  and  find the line that specifies the elasticsearch server URL, and replace the port number (9200 by default) with 80:

   elasticsearch: "http://"+window.location.hostname+":80",

mv kibana-3.1.1 /usr/share/nginx/kibana3

start the Nginx

service nginx start

sudo yum install httpd-tools-2.2.15
Then generate a login that will be used in Kibana to save and share dashboards (substitute your own username):
sudo htpasswd -c /etc/nginx/conf.d/kibana.myhost.org.htpasswd user

Install Logstash

yum install https://download.elasticsearch.org/logstash/logstash/packages/centos/logstash-1.4.2-1_2c0f5a1.noarch.rpm -y

Creating Certificates

cd /etc/pki/tls; sudo openssl req -x509 -batch -nodes -days 3650 -newkey rsa:2048 -keyout private/logstash-forwarder.key -out certs/logstash-forwarder.crt


cat << EOF >> /etc/logstash/conf.d/01-lumberjack-input.conf
input {
  lumberjack {
    port => 5000
    type => "logs"
    ssl_certificate => "/etc/pki/tls/certs/logstash-forwarder.crt"
    ssl_key => "/etc/pki/tls/private/logstash-forwarder.key"
  }
}
EOF

cat << EOF >> /etc/logstash/conf.d/10-syslog.conf
filter {
  if [type] == "syslog" {
    grok {
      match => { "message" => "%{SYSLOGTIMESTAMP:syslog_timestamp} %{SYSLOGHOST:syslog_hostname} %{DATA:syslog_program}(?:\[%{POSINT:syslog_pid}\])?: %{GREEDYDATA:syslog_message}" }
      add_field => [ "received_at", "%{@timestamp}" ]
      add_field => [ "received_from", "%{host}" ]
    }
    syslog_pri { }
    date {
      match => [ "syslog_timestamp", "MMM  d HH:mm:ss", "MMM dd HH:mm:ss" ]
    }
  }
}
EOF


cat << EOF >> /etc/logstash/conf.d/30-lumberjack-output.conf
output {
  elasticsearch { host => localhost }
  stdout { codec => rubydebug }
}
EOF




On Logstash Server

Copy the SSL certificate to Server (substitute with your own login):

scp /etc/pki/tls/certs/logstash-forwarder.crt user@server_private_IP:/tmp


Install Logstash Forwarder Package

yum install -y http://packages.elasticsearch.org/logstashforwarder/centos/logstash-forwarder-0.3.1-1.x86_64.rpm

Next, you will want to install the Logstash Forwarder init script, so it starts on bootup. We will use the init script provided by logstashbook.com:

cd /etc/init.d/; sudo curl -o logstash-forwarder http://logstashbook.com/code/4/logstash_forwarder_redhat_init
sudo chmod +x logstash-forwarder

The init script depends on a file called /etc/sysconfig/logstash-forwarder. A sample file is available to download:

sudo curl -o /etc/sysconfig/logstash-forwarder http://logstashbook.com/code/4/logstash_forwarder_redhat_sysconfig

sudo vi /etc/sysconfig/logstash-forwarder
And modify the LOGSTASH_FORWARDER_OPTIONS value so it looks like the following:
LOGSTASH_FORWARDER_OPTIONS="-config /etc/logstash-forwarder -spool-size 100"
Save and quit.

Now copy the SSL certificate into the appropriate location (/etc/pki/tls/certs):

sudo cp /tmp/logstash-forwarder.crt /etc/pki/tls/certs/

Configure Logstash Forwarder
On Server, create and edit Logstash Forwarder configuration file, which is in JSON format:

cat << EOF > /etc/logstash-forwarder
{
  "network": {
    "servers": [ "192.168.255.1:5000" ],
    "timeout": 15,
    "ssl ca": "/etc/pki/tls/certs/logstash-forwarder.crt"
  },
  "files": [
    {
      "paths": [
        "/var/log/messages",
        "/var/log/secure"
       ],
      "fields": { "type": "syslog" }
    }
   ]
}

EOF


Note that this is where you would add more files/types to configure Logstash Forwarder to other log files to Logstash on port 5000.

Now we will want to add the Logstash Forwarder service with chkconfig:

sudo chkconfig --add logstash-forwarder

Now start Logstash Forwarder to put our changes into place:

sudo service logstash-forwarder start


Now checkout the kibana server IP to get the dashboard

Poodle-SSLv3 Vulnerability

A vulnerability in SSLv3 encryption protocol was disclosed. This vulnerability, known as  POODLE (Padding Oracle On Downgraded Legacy Encryption), allows an attacker to read information encrypted with this version of the protocol in plain text using a man-in-the-middle attack.

Although SSLv3 is an older version of the protocol which is mainly obsolete, many pieces of software still fall back on SSLv3 if better encryption options are not available. More importantly, it is possible for an attacker to force SSLv3 connections if it is an available alternative for both participants attempting a connection

How to test for SSL POODLE vulnerability?
$ openssl s_client -connect google.com:443 -ssl3
If there is a handshake failure then the server is not supporting SSLv3 and it is secure from this vulnerability. Otherwise it is required to disable SSLv3 support.


The POODLE vulnerability exists because the SSLv3 protocol does not adequately check the padding bytes that are sent with encrypted messages.

Since these cannot be verified by the receiving party, an attacker can replace these and pass them on to the intended destination. When done in a specific way, the modified payload will potentially be accepted by the recipient without complaint.

The POODLE vulnerability does not represent an implementation problem and is an inherent issue with the entire protocol, there is no workaround and the only reliable solution is to not use it.

In nginx configuration, just after the "ssl on;" line, add the following to allow only TLS protocols:

ssl_protocols TLSv1.2 TLSv1.1 TLSv1;

Apache Web Server

Inside /etc/httpd/conf.d/ssl.conf or httpd.conf you can find the SSLProtocol directive. If this is not available, create it. Modify this to explicitly remove support for SSLv3:

SSLProtocol all -SSLv3 -SSLv2


Ha-Proxy
To disable SSLv3 in an HAProxy load balancer, you will need to open the haproxy.cfg file.

sudo nano /etc/haproxy/haproxy.cfg
frontend name
    bind public_ip:443 ssl crt /path/to/certs no-sslv3

Postfix

In Postfix conf /etc/postfix/main.cf add.
smtpd_tls_mandatory_protocols=!SSLv2, !SSLv3


In Dovecot

sudo nano /etc/dovecot/conf.d/10-ssl.conf
ssl_protocols = !SSLv3 !SSLv2

Tomcat

Edit @ $TOMCAT_HOME/conf/server.xml.

Tomcat 5 and 6:

    <Connector port="8443" protocol="org.apache.coyote.http11.Http11Protocol"
               maxThreads="150" SSLEnabled="true" scheme="https" secure="true"
               clientAuth="false" sslEnabledProtocols = "TLSv1,TLSv1.1,TLSv1.2" />
Tomcat >= 7

    <Connector port="8443" protocol="org.apache.coyote.http11.Http11Protocol"
               maxThreads="150" SSLEnabled="true" scheme="https" secure="true"
               clientAuth="false" sslProtocols = "TLSv1,TLSv1.1,TLSv1.2" />