## LiteSpeed Web Server
Users' Manual

### Version 6.3 — Rev. 4

- License Enterprise
- Introduction
- Installation
- Administration
- Security
- Configuration
  - Server General
  - Server Log
  - Server Tuning
  - Server Security
  - Page Cache
  - PageSpeed Config
  - External Apps
  - Fast CGI App
  - Fast CGI Authorizer
  - LSAPI App
  - Servlet Engine
  - Web Server
  - Piped logger
  - Load Balancer
  - Script Handler
  - PHP
  - App Server Settings
  - Listener General
  - Listener SSL
  - Virtual Host Templates
  - Virtual Host Basic
  - Virtual Host General
  - Virtual Host Security
  - Virtual Host SSL
  - Virtual Host PageSpeed Config
  - Rewrite
  - Context
  - Static Context
  - Java Web App Context
  - Servlet Context
  - Fast CGI Context
  - LSAPI Context
  - Proxy Context
  - CGI Context
  - Load Balancer Context
  - Redirect Context
  - App Server Context
  - Rack/Rails Context
  - Add-ons
- Web Console
  - Admin Console General
  - Admin Console Security
  - Admin Listener General
  - Admin Listener SSL

# Listeners SSL

## Table of Contents

### SSL Private Key & Certificate⇑

#### Description

Every SSL listener requires a paired SSL private key and SSL certificate. Multiple SSL listeners can share the same key and certificate.
You can generate SSL private keys yourself using an SSL software package, such as OpenSSL. SSL certificates can also be purchased from an authorized certificate issuer like VeriSign or Thawte. You can also sign the certificate yourself. Self-signed certificates will not be trusted by web browsers and should not be used on public websites containing critical data. However, a self-signed certificate is good enough for internal use, e.g. for encrypting traffic to LiteSpeed Web Server's WebAdmin Console.

### Private Key File⇑

#### Description

The filename of the SSL private key file. The key file should not be encrypted.

#### Syntax

Filename which can be an absolute path or a relative path to $SERVER_ROOT.

#### Tips

The private key file should be placed in a secured directory that allows read-only access to the user the server runs as.

### Certificate File⇑

#### Description

The filename of the SSL certificate file.

#### Syntax

Filename which can be an absolute path or a relative path to $SERVER_ROOT.

#### Tips

The certificate file should be placed in a secured directory, which allows read-only access to the user that the server runs as.

### Chained Certificate⇑

#### Description

Specifies whether the certificate is a chained certificate or not. The file that stores a certificate chain must be in PEM format, and the certificates must be in the chained order, from the lowest level (the actual client or server certificate) to the highest level (root) CA.

#### Syntax

Select from radio box

### CA Certificate Path⇑

#### Description

Specifies the directory where the certificates of certification authorities (CAs) are kept. Those certificates are used for client certificate authentication and constructing the server certificate chain, which will be sent to browsers in addition to the server certificate.

#### Syntax

path

### CA Certificate File⇑

#### Description

Specifies the file that contains all certificates of certification authorities (CAs) for chained certificates. This file is simply the concatenation of PEM-encoded certificate files, in order of preference. This can be used as an alternative or in addition to CA Certificate Path. Those certificates are used for client certificate authentication and constructing the server certificate chain, which will be sent to browsers in addition to the server certificate.

#### Syntax

Filename which can be an absolute path or a relative path to $SERVER_ROOT.

### Protocol Version⇑

#### Description

A selection of SSL protocols accepted by the listener.
Options include: SSL v3.0, TLS v1.0, TLS v1.1, TLS v1.2, TLS v1.3.

#### Syntax

Select from checkbox

### Ciphers⇑

#### Description

Specifies the cipher suite to be used when negotiating the SSL handshake. LSWS supports cipher suites implemented in SSL v3.0, TLS v1.0, TLS v1.2, and TLS v1.3.

#### Syntax

Colon-separated string of cipher specifications.

#### Example

ECDHE-RSA-AES128-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH

#### Tips

We recommend leaving this field blank to use our default cipher which follows SSL cipher best practices.

### Enable ECDH Key Exchange⇑

#### Description

Allows use of Elliptic Curve Diffie-Hellman key exchange for further SSL encryption.

#### Syntax

Select from radio box

#### Tips

ECDH key exchange is more secure than using just an RSA key. ECDH and DH key exchange are equally secure.
Enabling ECDH key exchange will increase CPU load and is slower than using just an RSA key.

### Enable DH Key Exchange⇑

#### Description

Allows use of Diffie-Hellman key exchange for further SSL encryption.

#### Syntax

Select from radio box

#### Tips

DH key exchange is more secure than using just an RSA key. ECDH and DH key exchange are equally secure.
Enabling DH key exchange will increase CPU load and is slower than ECDH key exchange and RSA. ECDH key exchange is preferred when available.

### DH Parameter⇑

#### Description

Specifies the location of the Diffie-Hellman parameter file necessary for DH key exchange.

#### Syntax

Filename which can be an absolute path or a relative path to $SERVER_ROOT.

### SSL Renegotiation Protection⇑

#### Description

Specifies whether to enable SSL Renegotiation Protection to defend against SSL handshake-based attacks. The default value is "Yes".

#### Syntax

Select from radio box

#### Tips

This setting can be enabled at the listener and virtual host levels.

### Enable Session Cache⇑

#### Description

Enables session id caching using OpenSSL's default setting. Default value is "No".

#### Syntax

Select from radio box

### Enable Session Tickets⇑

#### Description

Enables session tickets using OpenSSL's default session ticket setting. Server-level setting must be set to "Yes" for Virtual Host setting to take effect.
Default values:
Server-level: Yes
VH-Level: Yes

#### Syntax

Select from radio box

### ALPN⇑

#### Description

Selectively enable HTTP/3, HTTP/2, and SPDY HTTP network protocols.
If you wish to disable SPDY, HTTP/2, and HTTP3, check "None" and leave all other boxes unchecked.
Default value: All enabled

#### Syntax

Select from checkbox

#### Tips

This setting can be set at the listener and virtual host levels.

### Open HTTP3/QUIC (UDP) port⇑

#### Description

Allows the use of the HTTP3/QUIC network protocol for virtual hosts mapped to this listener. For this setting to take effect, Enable HTTP3/QUIC must also be set to Yes at the server level. Default value is Yes.

#### Tips

When this setting is set to Yes, HTTP3/QUIC can still be disabled at the virtual host level through the Enable HTTP3/QUIC setting.

### OCSP Stapling⇑

#### Description

Online Certificate Status Protocol (OCSP) is a more efficient method of checking whether a digital certificate is valid. It works by communicating with another server — the OCSP responder — to get verification that the certificate is valid instead of checking through certificate revocation lists (CRL).
OCSP stapling is a further improvement on this protocol, allowing the server to check with the OCSP responder at regular intervals instead of every time a certificate is requested. See the OCSP Wikipedia page for more details.

### Enable OCSP Stapling⇑

#### Description

Determines whether to enable OCSP stapling, a more efficient way of verifying public key certificates.

#### Syntax

Select from radio box

### OCSP Response Max Age (secs)⇑

#### Description

This option sets the maximum allowable age for an OCSP response. If an OCSP response is older than this maximum age, the server will contact the OCSP responder for a new response. The default value is 86400. Maximum age can be turned off by setting this value to -1.

#### Syntax

Integer of seconds

### OCSP Responder⇑

#### Description

Specifies the URL of the OCSP responder to be used. If not set, the server will attempt to contact the OCSP responder detailed in the certificate authority's issuer certificate. Some issuer certificates may not have an OCSP responder URL specified.

#### Syntax

URL starting with http://

#### Example

http://rapidssl-ocsp.geotrust.com

### OCSP CA Certificates⇑

#### Description

Specifies the location of the file where OCSP certificate authority (CA) certificates are stored. These certificates are used to check responses from the OCSP responder (and make sure those responses are not spoofed or otherwise compromised). This file should contain the whole certificate chain. If this file does not contain the root certificate, LSWS should be able to find the root certificate in your system directory without you adding it to the file, but, if this validation fails, you should try adding your root certificate to this file.
This setting is optional. If this setting is not set, the server will automatically check CA Certificate File.

#### Syntax

Filename which can be an absolute path or a relative path to $SERVER_ROOT.

### Client Verification⇑

#### Description

Enterprise Edition Only Specifies the type of client certifcate authentication. Available types are:

- None: No client certificate is required.
- Optional: Client certificate is optional.
- Require: The client must has valid certificate.
- Optional_no_ca: Same as optional.

The default is "None".

#### Syntax

Select from drop down list

#### Tips

"None" or "Require" are recommended.

### Verify Depth⇑

#### Description

Enterprise Edition Only Specifies how deeply a certificate should be verified before determining that the client does not have a valid certificate. The default is "1".

#### Syntax

Select from drop down list

### Client Revocation Path⇑

#### Description

Enterprise Edition Only Specifies the directory containing PEM-encoded CA CRL files for revoked client certificates. The files in this directory have to be PEM-encoded. These files are accessed through hash filenames, hash-value.rN. Please refer to openSSL or Apache mod_ssl documentation regarding creating the hash filename.

#### Syntax

path

### Client Revocation File⇑

#### Description

Enterprise Edition Only Specifies the file containing PEM-encoded CA CRL files enumerating revoked client certificates. This can be used as an alternative or in addition to Client Revocation Path.

#### Syntax

Filename which can be an absolute path or a relative path to $SERVER_ROOT.