- OS Support
- Enterprise Edition Reference Manual
- 136. Man Pages
- 137. Configuration
- 138. Language
- 139. Extension Modules
- 140. Input Modules
- 141. Processor Modules
- 142. Output Modules
- 142.1. Microsoft Azure (om_azure)
- 142.2. Batched compression (om_batchcompress)
- 142.3. Blocker (om_blocker)
- 142.4. DBI (om_dbi)
- 142.5. Elasticsearch (om_elasticsearch)
- 142.6. EventDB (om_eventdb)
- 142.7. Program (om_exec)
- 142.8. File (om_file)
- 142.9. Go (om_go)
- 142.10. HTTP(s) (om_http)
- 142.11. Java (om_java)
- 142.12. Kafka (om_kafka)
- 142.13. Null (om_null)
- 142.14. ODBC (om_odbc)
- 142.15. Perl (om_perl)
- 142.16. Named pipes (om_pipe)
- 142.17. Python (om_python)
- 142.18. Raijin (om_raijin)
- 142.19. Redis (om_redis)
- 142.20. Ruby (om_ruby)
- 142.21. TLS/SSL (om_ssl)
- 142.22. TCP (om_tcp)
- 142.23. UDP (om_udp)
- 142.24. UDP with IP spoofing (om_udpspoof)
- 142.25. Unix domain sockets (om_uds)
- 142.26. WebHDFS (om_webhdfs)
- 142.27. ZeroMQ (om_zmq)
- NXLog Manager
- NXLog Add-Ons
The om_ssl module uses the OpenSSL library to provide an SSL/TLS transport. It behaves like the om_tcp module, except that an SSL handshake is performed at connection time and the data is received over a secure channel. Log messages transferred over plain TCP can be eavesdropped or even altered with a man-in-the-middle attack, while the om_ssl module provides a secure log message transport.
|To examine the supported platforms, see the list of installer packages in the Available Modules chapter.|
The module connects to the IP address or hostname defined in this directive. If additional hosts are specified on new lines, the module works in a failover configuration. If a destination becomes unavailable, the module automatically fails over to the next one. If the last destination becomes unavailable, the module fails over to the first destination.
The port number can be defined by appending it at the end of the hostname or IP address using a colon as a separator (
host:port). IPv6 addresses must be enclosed in square brackets (
[host]:port). For each destination with no port number defined here, the port number specified in the Port directive is used. Port numbers defined here take precedence over any port number defined in the Port directive.
The module connects to the port number on the destination host defined in this directive. This configuration is only used for any destination that does not have a port number specified in the Host directive. If no port is configured for a destination in either directive, the default port is used, which is port 514.
|The Port directive will become deprecated from NXLog EE 6.0. After that, the port can only be defined in the Host directive.|
This boolean directive specifies that the connection should be allowed without certificate verification. If set to TRUE the connection will be allowed even if the remote server presents an unknown or self-signed certificate. The default value is FALSE: the remote socket must present a trusted certificate.
This specifies the path to a directory containing certificate authority (CA) certificates, which will be used to check the certificate of the remote socket. The certificate filenames in this directory must be in the OpenSSL hashed format. A remote’s self-signed certificate (which is not signed by a CA) can also be trusted by including a copy of the certificate in this directory.
This specifies the path of the certificate authority (CA) certificate, which will be used to check the certificate of the remote socket. To trust a self-signed certificate presented by the remote (which is not signed by a CA), provide that certificate instead.
This optional directive specifies the certificate thumbprint of the certificate authority (CA), which is used to look up the CA certificate from the Windows certificate store. The hexadecimal fingerprint string can be copied straight from Windows Certificate Manager (certmgr.msc), whitespaces are automatically removed. This directive is only supported on Windows. This directive and the CADir and CAFile directives are mutually exclusive.
This specifies the path of the certificate file to be used for the SSL handshake.
This specifies the path of the certificate key file to be used for the SSL handshake.
This optional directive specifies the certificate thumbprint to be used for the SSL handshake. The hexadecimal fingerprint string can be copied straight from Windows Certificate Manager (certmgr.msc), whitespaces are automatically removed. This directive is only supported on Windows. This directive and the CertFile and CertKeyFile directives are mutually exclusive.
This specifies the path to a directory containing certificate revocation lists (CRLs), which will be consulted when checking the certificate of the remote socket. The certificate filenames in this directory must be in the OpenSSL hashed format.
This specifies the path of the certificate revocation list (CRL) which will be used to check the certificate of the remote socket against.
With this directive, a password can be supplied for the certificate key file defined in CertKeyFile. This directive is not needed for passwordless private keys.
This optional directive specifies the local port number of the connection. If this is not specified, a random high port number will be used, which is not always ideal in firewalled network environments.
Due to the required
This optional directive sets the reconnect interval in seconds. If it is set, the module attempts to reconnect in every defined second. If it is not set, the reconnect interval will start at 1 second and doubles with every attempt. If the duration of the successful connection is greater than the current reconnect interval, then the reconnect interval will be reset to 1 sec.
|The Reconnect directive must be used with caution. If it is used on multiple systems, it can send reconnect requests simultaneously to the same destination, potentially overloading the destination system. It may also cause NXLog to use unusually high system resources or cause NXLog to become unresponsive.|
This optional directive specifies the host name used for Server Name Indication (SNI).
This optional directive can be used to set the permitted SSL cipher list, overriding the default. Use the format described in the ciphers(1ssl) man page.
|If RSA or DSA ciphers with Diffie-Hellman key exchange are used, DHFile can be set for specifying custom dh-parameters.|
This boolean directive allows you to enable data compression when sending data over the network. The compression mechanism is based on the zlib compression library. If the directive is not specified, it defaults to FALSE (the compression is disabled).Note
Some Linux packages (for example, Debian) use the OpenSSL library provided by the OS and may not support the zlib compression mechanism. The module will emit a warning on startup if the compression support is missing. The generic deb/rpm packages are bundled with a zlib-enabled libssl library.
This directive can be used to set the allowed SSL/TLS protocol(s). It takes a comma-separated list of values which can be any of the following:
TLSv1.3. By default, the
TLSv1.3protocols are allowed. Note that the OpenSSL library shipped by Linux distributions may not support
SSLv3, and these will not work even if enabled with this directive.
This boolean directive is used to turn off the network optimization performed by Nagle’s algorithm. Nagle’s algorithm is a network optimization tweak that tries to reduce the number of small packets sent out to the network, by merging them into bigger frames, and by not sending them to the other side of the session before receiving the ACK. If this directive is unset, the TCP_NODELAY socket option will not be set.
The following procedures are exported by om_ssl.
Force a reconnection. This can be used from a Schedule block to periodically reconnect to the server.Caution
The reconnect() procedure must be used with caution. If configured, it can attempt to reconnect after every event sent, potentially overloading the destination system.
Pre-v5 syntax examples are included, they will become invalid with NXLog EE 6.0.
This configuration reads log messages from socket and sends them in the NXLog binary format to another NXLog agent.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 <Input uds> Module im_uds UDS tmp/socket </Input> <Output ssl> Module om_ssl Host example.com:23456 CAFile %CERTDIR%/ca.pem CertFile %CERTDIR%/client-cert.pem CertKeyFile %CERTDIR%/client-key.pem KeyPass secret AllowUntrusted TRUE OutputType Binary </Output> # Using the syntax prior to NXLog EE 5, # where the port is defined in a separate directive. #<Output ssl> # Module om_ssl # Host example.com # Port 23456 # CAFile %CERTDIR%/ca.pem # CertFile %CERTDIR%/client-cert.pem # CertKeyFile %CERTDIR%/client-key.pem # KeyPass secret # AllowUntrusted TRUE # OutputType Binary #</Output>
This configuration sends logs to another NXLog agent in a failover configuration (multiple Hosts defined).