The Secure Sockets Layer (SSL) is a commonly-used protocol for managing the security of a message transmission on the Internet, and offers a greater level of protection than standard HTTP transmission.

DataSource is capable of communicating with its peers over SSL, providing an encrypted channel over which the data sources can publish their data.

Making an SSL Connection

SSL certificates can be configured at either or both client and server ends of the channel - DataSource is said to be operating in server mode when requesting information and in client mode when receiving information.

Server mode only configuration

To configure DataSource for SSL when in server mode, use the datasrc-sslport option to select the network port to listen for SSL connections from DataSource peers.

It is possible for DataSource to accept both SSL and non-SSL connections on different ports. Non-SSL connections should be configured using the datasrc-port option.

Client mode only configuration

To configure DataSource for SSL when in client mode, use the ssl option in the add-peer entry for the DataSource peer that acts as server.

Note: There is no failback to non-SSL operation should the SSL connection fail to be established.

Server and client mode configuration

To configure DataSource for SSL at both client and server ends of the channel, use the start-ssl group. This group is needed in the configuration file of both client and server applications.

Configuring hardware devices

OpenSSL has built-in support for cryptographic acceleration. In newer versions of OpenSSL (versions of 0.9.6 that include the name engine in the version) an application can get a reference to a specific representation, often a hardware device. These representations are referred to as Engines.

These following configuration options are set by editing the ssl-engine-id and ssl-engine-flags configuration options.

`datasrc-ssl-enable`

Type: Boolean
Default: FALSE

SSL enable SSL

`datasrc-ssl-port`

Type: Integer
Default: 0

SSL port

`datasrc-ssl-certificate`

Type: String
Default: None

DataSource Server certificate

`datasrc-ssl-passwordfile`

Type: String
Default: None

file containing the password for the private key

`datasrc-ssl-privatekey`

Type: String
Default: None

private key file for the certificate

`datasrc-ssl-cipherlist`

Type: String
Default: None

optional list of ciphers to use

`datasrc-ssl-ssloptions`

Type: Integer
Default: 16777216
Acceptable Values:

Name	Value	Desc
SSL_OP_ALL	-2147483648
SSL_OP_NO_SSLv2	16777216
SSL_OP_NO_SSLv3	33554432
SSL_OP_NO_TLSv1	67108864
SSL_OP_NO_TLSv1_2	134217728
SSL_OP_NO_TLSv1_1	268435456
SSL_OP_NO_DTLSv1	67108864
SSL_OP_NO_DTLSv1_2	134217728

optional list of SSL options to use

`ssl-debug`

Type: Boolean
Default: FALSE

Enables SSL connection negotiation debugging.

`ssl-random-seed`

Type: Function
Default: None

Configures the seeding of the OpenSSL random number generator, which Caplin Liberator uses for session IDs and HTTPS and DataSource SSL connections.

The parameters for this option are:

Name	Description
type	Type of random number generation. Must be one of the following: builtin This takes no arguments and uses various system commands to produce random output. file Uses the data in the file to seed the random number generator. exec Uses the output of the command to seed the random number generator.
arg1	If type is file, this is a filename (relative to the root directory).<br If type is exec, this is a command (relative to the root directory)
arg2	If type is file, this specifies how many bytes of the file to use. If type if exec, thisspecifies how many bytes of the output to use.

Examples:

ssl-random-seed builtin
ssl-random-seed file etc/randomdata
ssl-random-seed file etc/randomdata 1024
ssl-random-seed exec etc/random.sh
ssl-random-seed exec etc/random.sh 512

Note: On Linux OpenSSL is seeded by a hardware device so using ssl-randomseed may be unnecessary.

`ssl-engine-id`

Type: String
Default: None

This option configures the SSL hardware or software engine to support. The available engines are listed in the table below:

ssl-engine-id option	Engine
openssl	The engine uses the normal built-in software functions (this is the default)
openbsd_dev_crypto	On OpenBSD, this engine will use the kernel level cryptography built into the OS.
aep	Uses the Aep acceleration hardware
atalla	Uses the Compaq Atalla acceleration hardware
chil	Uses the nCipher CHIL acceleration hardware
cswift	Uses the CryptoSwift acceleration hardware
nuron	Uses the Nuron acceleration hardware
ubsec	Uses the Broadcom uBSec acceleration hardware
sureware	Uses the SureWare acceleration hardware

`ssl-engine-flags`

Type: String
Default: all

This option affects the flags passed to the engine implementation.

The flags in the table below may be ORed together using the "|" operator to represent multiple flags: for example "dsa|rsa" equates to using only DSA and RSA operations

Flag	Description
dh	Limit engine usage to only DH operations
dsa	Limit engine usage to only DSA operations
rand	Limit engine usage to only random operations
rsa	Limit engine usage to only RSA operations
all	Allow OpenSSL to use any of the above implementations

`ssl-config-name`

Type: String
Default: None

The OpenSSL config name to load (default=system default)