The module accepts connections on the IP address or hostname and port defined here. The default address is localhost and the default port is 2514. 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). The port section of this directive and the Port directive are mutually exclusive. In case both is defined, the port number defined here takes precedence over a port defined in the Port directive. In case none of them is defined, the default port is used.
To listen on multiple addresses or ports in a single module instance, this directive can be repeated multiple times. Both IPv4 and IPv6 addresses are supported. If a DNS name is used, the number of addresses or cnames should be kept below 16 to avoid potential issues caused by DNS response size limits.

The module listens for incoming connections on the port defined in this directive. The default is port 2514.

This optional directive may be used to specify a whitelist of IP addresses and/or networks that are allowed to connect. The directive can be specified more than once to add different IPs or networks to the whitelist. This directive is only active when the Listen or ListenAddr directives are present. In the absence of this directive, there is no restriction on the hosts which may connect to a listening module. The following formats may be used:

This boolean directive specifies whether the connection should be allowed with an expired certificate. If set to TRUE, the remote client will be able to connect with an expired certificate. The default is FALSE: the certificate must not be expired. This directive is only valid if RequireCert is set to TRUE.

This boolean directive specifies that the remote connection should be allowed regardless of the certificate verification results. If set to TRUE, the remote client will be able to connect with any unexpired certificate. The default value is FALSE: the remote server must present a trusted certificate.

This directive specifies a path to a directory containing certificate authority (CA) certificates. These certificates will be used to verify the certificate presented by the remote client. The certificate files must be named using the OpenSSL hashed format, i.e. the hash of the certificate followed by .0, .1 etc. To find the hash of a certificate using OpenSSL:

$ openssl x509 -hash -noout -in ca.crt

This specifies the path of the certificate authority (CA) certificate that will be used to verify the certificate presented by the remote client. A remote client’s self-signed certificate (which is not signed by a CA) can be trusted by specifying the remote client certificate itself. In case of certificates signed by an intermediate CA, the certificate specified must contain the complete certificate chain (certificate bundle).

This optional directive specifies the thumbprint of the certificate authority (CA) certificate that will be used to verify the certificate presented by the remote client. The hexadecimal fingerprint string can be copied from Windows Certificate Manager (certmgr.msc). Whitespaces are automatically removed. The certificate must be added to a Windows certificate store that is accessible by NXLog. This directive is only supported on Windows and is mutually exclusive with the CADir and CAFile directives.

This optional boolean directive, when set to TRUE, enables the loading of all available Windows certificates into NXLog, for use during remote certificate verification. Any required certificates must be added to a Windows certificate store that NXLog can access. This directive is mutually exclusive with the CAThumbprint, CADir and CAFile directives.

This specifies the path of the certificate file that will be presented to the remote client during the SSL handshake.

This specifies the path of the private key file that was used to generate the certificate specified by the CertFile directive. This is used for the SSL handshake.

This optional directive specifies the thumbprint of the certificate that will be presented to the remote client during the SSL handshake. The hexadecimal fingerprint string can be copied from Windows Certificate Manager (certmgr.msc). Whitespaces are automatically removed. The certificate must be imported to the Local Computer\Personal certificate store in PFX format for NXLog to find it. To create a PFX file from the certificate and private key using OpenSSL:

$ openssl pkcs12 -export -out server.pfx -inkey server.key -in server.pem

This directive specifies a path to a directory containing certificate revocation list (CRL) files. These CRL files will be used to check for certificates that were revoked and should no longer be accepted. The files must be named using the OpenSSL hashed format, i.e. the hash of the issuer followed by .r0, .r1 etc. To find the hash of the issuer of a CRL file using OpenSSL:

$ openssl crl -hash -noout -in crl.pem

This specifies the path of the certificate revocation list (CRL) which will be used to check for certificates that have been revoked and should no longer be accepted. Example to generate a CRL file using OpenSSL:

$ openssl ca -gencrl -out crl.pem

This optional directive specifies a file with dh-parameters for Diffie-Hellman key exchange. These parameters can be generated with dhparam(1ssl). If this directive is not specified, default parameters will be used. See the OpenSSL Wiki for further details.

This directive specifies the passphrase of the private key specified by the CertKeyFile directive. A passphrase is required when the private key is encrypted. Example to generate a private key with Triple DES encryption using OpenSSL:

$ openssl genrsa -des3 -out server.key 2048

This boolean value specifies that the remote client must present a certificate. If set to TRUE and a certificate is not presented during the SSL handshake, the connection will be refused. The default value is TRUE: each connection must use a certificate.

This optional directive can be used to set the permitted cipher list for TLSv1.2 and below, overriding the default. Use the format described in the ciphers(1ssl) man page. For example specify RSA:!COMPLEMENTOFALL to include all ciphers with RSA authentication but leave out ciphers without encryption.

This optional directive can be used to set the permitted cipher list for TLSv1.3. Use the same format as in the SSLCipher directive. Refer to the OpenSSL documentation for a list of valid TLS v1.3 cipher suites. The default value is:

TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256

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: SSLv2, SSLv3, TLSv1, TLSv1.1, TLSv1.2, and TLSv1.3. By default, the TLSv1.2 and TLSv1.3 protocols are allowed. Note that the OpenSSL library shipped by Linux distributions may not support SSLv2 and SSLv3, and these will not work even if enabled with this directive.