Description
===========
Fully automated Installation and configuration of ossec-servers and ossec-agents
Manage the key generation and distribution between a server and multiple agents
Clean queues on the server if needed (rid)

Requirements
============
Any of:
* Ubuntu 12.04+
* Debian 7.0+
* CentOS 6.0+
(should work with ossec systems if you have the packages)

Attributes
==========
# General Attributes

The attributes below follow the same namespace syntax that OSSEC does. Refer to
the official [OSSEC Documentation](http://www.ossec.net/doc/syntax/ossec_config.html)
for more information.

Default attributes from the cookbook:

    default["ossec"]["version"] = "2.8"
    default["ossec"]["syslog_output"]["ip"] = "127.0.0.1"
    default["ossec"]["syslog_output"]["port"] = "514"
    default["ossec"]["syslog_output"]["min_level"] = "5"
    default["ossec"]["receiver_port"] = "1514"
    default["ossec"]["log_alert_level"] = "1"
    default["ossec"]["email_alert_level"] = "7"
    default["ossec"]["agents"] = {}

Default attributes from the ossec-server role:

    "ossec" => {
      "email_notification" => 'yes',
      "email_to" => [
        'ossec@example.net',
      ],
      "email_from" => 'ossec-server@example.net',
      "email_idsname" => 'ossec',
      "smtp_server" => 'localhost',
      "white_list" => [
        '127.0.0.1',
        '10.1.0.0/16'
      ],
      "email_alerts" => {
        'recipient@example.net' => {
          'level' => '9',
          'group' => 'syscheck',
          'event_location_tag' => 'reputation',
          'event_location_search' => 'roles:*mongodb*',
          'format' => 'sms',
          'rule_id' => '100001',
          'tags' => [
            'do_not_delay',
            'do_not_group'
          ]
        }
      },
      "server" => {
        "service_name" => 'ossec-hids-server'
      },
      "syscheck" => {
        "frequency" => '7200',
        "alert_new_files" => 'yes',
        "auto_ignore" => 'no',
        "directories" => {
          '/bin' => {
            'report_changes' => 'no',
            'realtime' => 'yes'
          },
          '/sbin' => {
            'report_changes' => 'no',
            'realtime' => 'yes'
          },
          '/usr/bin' => {
            'report_changes' => 'no',
            'realtime' => 'yes'
          },
          '/usr/sbin' => {
            'report_changes' => 'no',
            'realtime' => 'yes'
          },
          '/etc' => {
            'report_changes' => 'yes',
            'realtime' => 'yes'
          },
          '/tmp' => {
            'report_changes' => 'yes',
            'realtime' => 'no'
          }
        },
        "ignore" => {
          '/etc/openvpn/openvpn-status.log' => {},
          '/etc/motd' => {},
          '/etc/mcollective/facts.yaml' => {},
          '/etc/blkid.tab' => {},
          '/etc/mtab' => {},
          '/etc/hosts.deny' => {},
          '/etc/mail/statistics => {}',
          '/etc/random-seed' => {},
          '/etc/adjtime' => {},
          '/etc/prelink.cache' => {},
          '/etc/dnscache/stats' => {},
          '/etc/dnscache/log' => {},
          '/etc/dnscache2/stats' => {},
          '/etc/dnscache2/log' => {},
          '/etc/tinydns/stats' => {},
          '/etc/tinydns/log' => {}
        }
      },
      "syslog_files" => {
        '/var/log/syslog' => {},
        '/var/log/auth.log' => {},
        '/var/log/daemon.log' => {},
        '/var/log/kern.log' => {},
        '/var/log/mail.log' => {},
        '/var/log/user.log' => {},
        '/var/log/cron.log' => {}
      }

```email_alerts``` is a hash of recipients and servers. Each recipient will
receive all of the alert for the listed location (the list is a regex).
```event_location_tag``` must contain a valid chef tag. All the nodes listed by
that tag will generate a separate ```email_alerts``` rule.
This is additional to the default list ```email_to``` and is used to send alert to
specific recipients for a limited number of hosts only.

# Local Rules Definitions
Rules are defined in Ruby Hash format and replicate the XML format of regular
[OSSEC Rules Syntax](http://www.ossec.net/doc/syntax/head_rules.html)
Each rule has a head, a body, tags and info (the last 2 being optional)

    head=   <rule id="12345" level="12" frequency="45" timeframe="60">
    body=     <description>Test Rule</description>
    body=     <match>Big Error</match>
    body=     <hostname>server1</hostname>
    tags=     <same_source_ip />
    tags=     <same_source_port />
    info=     <info type="link">http://IjustGotHacked.com</info>
            </rule>

The section below are parsed by the template. The following items are mandatory:
 * head/level
 * body/description

```
    "ossec" =>
      "rules" => {
        "100001" => {
          "head" => {
            "level" => "7",
            "maxsize" => "65536",
            "frequency" => "100",
            "timeframe" => "3600",
            "ignore" => "5",
            "overwrite" => "68321"
          },
          "body" => {
            "hostname_search" => "recipes:mms-agent",
            "description" => "Super Security Rule for application XYZ",
            "match" => "super dangerous error happened",
            "regex" => "^\d+Hello World$",
            "decoded_as" => "vsftpd",
            "category" => "windows",
            "srcip" => "192.168.1.254",
            "dstip" => "10.1.6.23",
            "user" => "bob",
            "program_name" => "nginx",
            "time" => "09:00-18:00",
            "weekday" => "monday,tuesday",
            "id" => "404",
            "url" => "/changepassword.php",
            "if_sid" => "100238",
            "if_group" => "authentication_success",
            "if_level" => "13",
            "if_matched_sid" => "12037",
            "if_matched_group" => "adduser",
            "if_matched_level" => "7",
            "options" => "no_email_alert",
            "check_diff" => "true",
            "group" => "syscheck"
          },
          "tags" => [
            "same_source_ip",
            "same_source_port",
            "same_dst_port",
            "same_location"
          ],
          "infos" => {
            "link" => "http://trac.example.net/ticket/12345",
            "text" => "the link above contains additional information"
          }
        }
      }
```

## hostname_search

To the exception of __hostname_search__, all attributes use the same syntax as the
ossec rule in XML format does.
__hostname_search__ in this cookbook represents a search query that is executed by
the server recipe to populate the ```<hostname>``` with the proper list of hosts,
dynamically pulled from chef. Search criterias can be anything that a chef search 
can take. Example: ```recipe:mongodb\:\:replicaset and tags:reputation```

# Local Decoders Definitions
Decoders are defined in JSON format and replicate the XML format of regular
[OSSEC Decoder Syntax](http://www.ossec.net/doc/syntax/head_decoders.html)

    "ossec" => {
      "decoders" => {
        'apache-errorlog' => {
          "program_name" => '^httpd|^apache2',
          "prematch" => {
            "parser" => '^\S+ [\w+\s*\d+ \S+ \d+] [\S+] |^[warn] |^[notice] |^[error]'
          },

        },
        'apache-errorlog-ip-custom' => {
          "parent" => 'apache-errorlog',
          "prematch" => {
            "offset" => 'after_parent',
            "parser" => '^[client'
          },
          "regex" => {
            "offset" => 'after_prematch',
            "parser" => '^ (\d+.\d+.\d+.\d+)]'
          },
          "order" => 'srcip'
        },
        'web-accesslog-custom' => {
          "parent" => 'web-accesslog',
          "type" => 'web-log',
          "prematch" => {
            "parser" => '^\d+.\d+.\d+.\d+ |^::ffff:\d+.\d+.\d+.\d+'
          },
          "regex" => {
            "parser" => '^\d+.\d+.\d+.\d+ \S+ (\d+.\d+.\d+.\d+) \S+ \S+ \S+ [\S+ \S\d+] "\w+ (\S+) HTTP\S+ (\d+) \S+ "(\S+)"'
          },
          "order" => 'srcip, url, id, extra_data'
        }
      }
    }

```prematch``` and ```regex``` are hashes that can have an ```offset``` value and
always have a ```parser``` value. See the ossec documentation for more information.

# Local Syslog Files and Syscheck Ignore Files
If you want specific log files to be monitored on specific agents, you can use
a `syslog_files` block in the agent node attributes. The `apply_to`
parameter of this block is a `Chef::Search()` that will expand to a list of
hosts. If the given agent belong to the list of hosts, it will add the logfile
to its local ossec configuration. log_format will default to "syslog" if not set.

If you want to ignore specific files in syscheck, similarly you can use the same
`apply_to` option as shown below:

```
default_attributes(
  "ossec" => {
    "syslog_files" => {
      '/var/log/supervisor/supervisor.log' => {
        'apply_to' => 'supervisor:*',
        'log_format' => 'syslog'
      }
    },
    "syscheck" => {
      "ignore" => {
        '/etc/openvpn/openvpn-status.log' => {
          'apply_to' => 'roles:vpn-server'
        },
        '^/opt/graphite/storage/' => {
          'apply_to' => 'roles:graphite-server OR roles:statsd-server',
          'type' => 'sregex'
        }
      }
    }
  }
)
```

# OSSEC Rules Enable/Disable
You can also choose what rules OSSEC it configured to load. Each of the rules in
/var/ossec/rules can be enabled and disabled at will with a very simple format.
Note that these do not have an apply_to option and are just boolean values, this
is because only the OSSEC server loads the rules into action. The following is
an example that will enable the normally disabled `symantec-av-rules.xml` and 
disable the `web_rules.xml`:

```
default_attributes(
  "ossec" => {
    "load_rules" => {
      'symantec-av_rules.xml' => true,
      'web_rules.xml' => false
    }
  }
)
```

# Commands and Auto-Response
Since OSSEC is an HIDS system, you can also enable and disable commands and 
active-response functionality and define your own as needed. You can enable
or disable existing defined commands and active-responses using the
`enable` flag, and target where they are set using the `apply_to` flag. You
can also define any of the allowed active-response options dynamically, such
as adding agent_id, rules_group, etc.
Here is an example of enabling the firewall-stop command and its auto-response
and changing it from the default local to all hosts and adding a `rules_group`
to the active-response definition so it only triggers on authentication
failures:

```
default_attributes(
  "ossec" => {
    "command" => {
      "firewall-stop" => {
        "enabled" => true
      }
    },
    "auto-response => {
      "firewall-stop" => {
        "enabled" => true,
        "location" => "all",
        "rules_group" => "authentication_failed,authentication_failures"
      }
    }
  }
)
```

Usage
=====
* `recipe[ossec-server]` should be a stand alone installation
* `recipe[ossec-agent]` should be added (via role[ossec-agent]) to all the nodes of the
environment

# Example Roles
## ossec-server
This role can be used to provision an ossec server:

```ruby
name 'ossec-server'
description 'OSSEC Server'
run_list(
  'recipe[ossec-ng::server]',
  'role[postfix]'
)
override_attributes(
  "ossec" => {
    "agent" => {
      "enable" => false
    }
  }
)
default_attributes(
  "ossec" => {
    "email_notification" => 'yes',
    "email_to" => [
      'ossec-alerts@example.net',
    ],
    "email_from" => 'ossec-server',
    "smtp_server" => 'localhost',
    "white_list" => [
      '127.0.0.1',
      '10.0.0.0/0'
    ],
    "email_alerts" => {
      'bob@example.net' => {
        'event_location_tag' => 'project1',
      },
      'alice@example.net' => {
        'event_location_tag' => 'project1',
        'group' => 'developers',
      },
      'eve@example.net' => {
        'event_location_tag' => 'project2',
        'group' => 'developers',
      },
      'mike@example.net' => {
        'event_location_search' => 'tags:project1 OR tags:project2 OR tags:project3',
        'group' => 'developers',
      },
      'group2@example.net' => {
        'event_location_search' => 'roles:application-server AND roles:python-django',
        'group' => 'frontend-group',
      },
    },
    "decoders" => {
      1 => {
        "name" => 'apache-errorlog',
        "program_name" => '^httpd|^apache2',
        "prematch" => {
          "parser" => '^\S+ [\w+\s*\d+ \S+ \d+] [\S+] |^[warn] |^[notice] |^[error]'
        },

      },
      2 => {
        "name" => 'apache-errorlog-ip-custom',
        "parent" => 'apache-errorlog',
        "prematch" => {
          "offset" => 'after_parent',
          "parser" => '^[client'
        },
        "regex" => {
          "offset" => 'after_prematch',
          "parser" => '^ (\d+.\d+.\d+.\d+)]'
        },
        "order" => 'srcip'
      },
      3 => {
        "name" => 'web-accesslog-custom',
        "parent" => 'web-accesslog',
        "type" => 'web-log',
        "prematch" => {
          "parser" => '^\d+.\d+.\d+.\d+ |^::ffff:\d+.\d+.\d+.\d+'
        },
        "regex" => {
          "parser" => '^\d+.\d+.\d+.\d+ \S+ (\d+.\d+.\d+.\d+) \S+ \S+ \S+ [\S+ \S\d+] "\w+ (\S+) HTTP\S+ (\d+) \S+ "(\S+)"'
        },
        "order" => 'srcip, url, id, extra_data'
      }
    },
    "rules" => {
      1002 => {
        "head" => {
          "level" => '2',
          "overwrite" => 'yes'
        },
        "body" => {
          "description" => 'Unknown problem somewhere in the system.',
          "match" => 'core_dumped|failure|error|Error|attack|bad |illegal |denied|refused|unauthorized|fatal|fail|Segmentation Fault|Corrupted|Traceback|raise',
          "options" => 'alert_by_email'
        }
      },
      1003 => {
        "head" => {
          "level" => '6',
          "maxsize" => '16384',
          "overwrite" => 'yes'
        },
        "body" => {
          "description" => 'Non standard syslog message (larger than 16kB).'
        }
      },
      100003 => {
        "head" => {
          "level" => '10'
        },
        "body" => {
          "description" => 'Successful sudo during non-business hours 6pm to 8am',
          "if_sid" => '5402,5403',
          "time" => '10pm - 12am'
        }
      },
      100004 => {
        "head" => {
          "level" => '10'
        },
        "body" => {
          "description" => 'Successful sudo during weekend.',
          "if_sid" => '5402,5403',
          "weekday" => 'weekends'
        }
      },
      100005 => {
        "head" => {
          "level" => '0'
        },
        "body" => {
          "description" => 'Silencing sudo errors from accounts allowed to sudo anytime',
          "if_sid" => '100004,100005',
          "match" => 'nagios'
        }
      },
      100006 => {
        "head" => {
          "level" => '0'
        },
        "body" => {
          "description" => 'Silencing ossec agent stop/start during business hours 8am to 6pm',
          "if_sid" => '502,503,504',
          "time" => '12:00-22:00',
          "weekday" => 'monday,tuesday,wednesday,thursday,friday'
        }
      },
      100007 => {
        "head" => {
          "level" => '8'
        },
        "body" => {
          "description" => 'Login outside of business hours 6pm to 8am',
          "if_sid" => '5501',
          "time" => '22:00-12:00'
        }
      },
      100008 => {
        "head" => {
          "level" => '8'
        },
        "body" => {
          "description" => 'Login during weekend.',
          "if_sid" => '5501',
          "weekday" => 'weekends'
        }
      },
      100009 => {
        "head" => {
          "level" => '0'
        },
        "body" => {
          "description" => 'Ignore logins alerts for systems accounts',
          "if_sid" => '100007,100008',
          "match" => 'ubuntu|nagios'
        }
      }
    }
  }
)
```

## ossec-agent
This role can be used to provision an ossec-agent

```ruby
name "ossec-agent"
description "OSSEC Agent"
run_list(
  "recipe[ossec-ng::agent]"
)
default_attributes(
  "ossec" => {
    "client" => {
      "service_name" => 'ossec-hids-client'
    },
    "syscheck" => {
      "frequency" => '7200',
      "alert_new_files" => 'yes',
      "auto_ignore" => 'no',
      "directories" => {
        '/bin' => {
          'report_changes' => 'no',
          'realtime' => 'yes'
        },
         '/boot' => {
          'report_changes' => 'no',
          'realtime' => 'no'
        },
        '/etc' => {
          'report_changes' => 'yes',
          'realtime' => 'no'
        },
        '/lib/lsb' => {
          'report_changes' => 'no',
          'realtime' => 'yes'
        },
        '/lib/modules' => {
          'report_changes' => 'no',
          'realtime' => 'yes'
        },
        '/lib/plymouth' => {
          'report_changes' => 'no',
          'realtime' => 'yes'
        },
        '/lib/security' => {
          'report_changes' => 'no',
          'realtime' => 'yes'
        },
        '/lib/terminfo' => {
          'report_changes' => 'no',
          'realtime' => 'yes'
        },
        '/lib/ufw' => {
          'report_changes' => 'no',
          'realtime' => 'yes'
        },
        '/lib/xtables' => {
          'report_changes' => 'no',
          'realtime' => 'no'
        },
        '/media' => {
          'report_changes' => 'no',
          'realtime' => 'no'
        },
        '/opt' => {
          'report_changes' => 'no',
          'realtime' => 'no'
        },
        '/root' => {
          'report_changes' => 'yes',
          'realtime' => 'no'
        },
        '/srv' => {
          'report_changes' => 'no',
          'realtime' => 'no'
        },
        '/sbin' => {
          'report_changes' => 'no',
          'realtime' => 'yes'
        },
        '/usr/' => {
          'report_changes' => 'yes',
          'realtime' => 'yes'
        },
        '/tmp' => {
          'report_changes' => 'no',
          'realtime' => 'no'
        }
      },
      "ignore" => {
        '/etc/openvpn/openvpn-status.log' => {}
        '/etc/motd' => {},
        '/etc/blkid.tab' => {},
        '/etc/mtab' => {},
        '/etc/mail/statistics' => {},
        '/etc/random-seed' => {},
        '/etc/adjtime' => {},
        '/etc/prelink.cache' => {},
        '/root/.bash_history' => {}
        '^/opt/graphite/storage/' => {
          'apply_to' => 'roles:graphite-server OR roles:statsd-server',
          'type' => 'sregex'
        },
        '^/usr/lib/elasticsearch' => {
          'apply_to' => 'roles:elastic-search-cluster',
          'type' => 'sregex'
        },
        '^/etc/chef/cache/checksums/' => {
          'apply_to' => 'roles:chef-client',
          'type' => 'sregex'
        },
        '^/srv/rsyslog/' => {
          'apply_to' => 'roles:rsyslog-server',
          'type' => 'sregex'
        },
        '^/etc/djbdns/public-dnscache/supervise/|^/etc/djbdns/tinydns-internal/supervise/|^/etc/djbdns/public-dnscache/log|^/etc/djbdns/tinydns-internal/log|^/etc/djbdns/tinydns-internal/root/data' => {
          'apply_to' => 'roles:djbdns-server',
          'type' => 'sregex'
        }
      }
    },
    "syslog_files" => {
      '/var/log/syslog' => {},
      '/var/log/auth.log' => {},
      '/var/log/daemon.log' => {},
      '/var/log/kern.log' => {},
      '/var/log/mail.log' => {},
      '/var/log/user.log' => {},
      '/var/log/cron.log' => {},
      '/var/log/chef/client.log' => {},
      '/var/log/supervisor/supervisor.log' => {
        'apply_to' => 'supervisor:*',
        'log_format' => 'syslog'
      },
      '/var/log/rabbitmq/rabbit1.log' => {
        'apply_to' => 'recipes:rabbitmq',
        'log_format' => 'multi-line:3'
      },
      '/var/log/nginx/access.log' => {
        'apply_to' => 'nginx:*',
        'log_format' => 'syslog'
      },
      '/var/log/nginx/error.log' => {
        'apply_to' => 'nginx:*',
        'log_format' => 'syslog'
      },
      '/var/log/nagios3/nagios.log' => {
        'apply_to' => 'roles:nagios-server',
        'log_format' => 'syslog'
      },
      '/var/log/nagios3/apache_access.log' => {
        'apply_to' => 'roles:nagios-server',
        'log_format' => 'syslog'
      },
      '/var/log/nagios3/apache_error.log' => {
        'apply_to' => 'roles:nagios-server',
        'log_format' => 'syslog'
      }
    }
  }
)
```

Author
======
Eric Renfro - psi-jack@linux-help.org - https://linux-help.org

Derived from works from:
Julien Vehent - julien@linuxwall.info - http://jve.linuxwall.info