DataSource SSL/TLS configuration

These DataSource configuration items enable you to set up secure communication between DataSource peers using the Secure Sockets Layer (SSL) of TCP/IP.

C-based DataSource applications implement SSL using OpenSSL, and the security certificate and private key are kept in separate PEM files (see datasrc-ssl-present-certificate and datasrc-ssl-privatekey).

Java-based DataSource applications use the Java Cryptography APIs, and a Java KeyStore (JKS) to hold the security certificate and private key (see datasrc-ssl-keystore). The KeyStore can be accessed using an alias (see datasrc-ssl-present-certificate).

The configuration items on this page apply to DataSource 6.2 and higher. For earlier DataSource versions, see section 12.8 "Direct connections using SSL" in the Liberator 6.0 Administration Guide.

datasrc-ssl-enable

Set datasrc-ssl-enable to TRUE to enable this DataSource to accept incoming SSL connections from peers.

To configure this DataSource to initiate an SSL connection to a peer, set the ssl option of this DataSource’s add-peer configuration item for the peer.

If you set datasrc-ssl-enable to TRUE, remember to specify values for the following configuration items:

Use in: C, Java

Syntax: datasrc-ssl-enable <boolean>

Type: boolean

Default value: FALSE (incoming SSL connections not accepted)

datasrc-ssl-certificate

Deprecated: deprecated from Caplin Platform 8 in favour of datasrc-ssl-present-certificate.

datasrc-ssl-accept-certificate

Specifies one or more certificates accepted (trusted) by this DataSource. This option is used for for certificate pinning when an SSL connection is being established with a dynamic peer such as one added by Discovery.

Overridden by add-peer:ssl-accept-certificate for specific connections.

This option is required if datasrc-ssl-enable is set to TRUE and dynamic peers are in use. Setting datasrc-ssl-accept-certificate is functionally equivalent to configuring add-peer:ssl-accept-certificate for all dynamically configured peers.

Use in: C, Java

Since: DSDK 7.1.30 (Liberator 7.1.30), DataSource for Java 7.1.22

Syntax:

C DataSource applications
datasrc-ssl-accept-certificate <path-to-ssl-certificate-pem-file> ...
Java DataSource applications
datasrc-ssl-accept-certificate <ssl-certificate-alias-in-java-keystore> ...

Type: string array

Default value: none

datasrc-ssl-present-certificate

Since: Caplin Platform 8 (a renaming of the now deprecated datasrc-ssl-certificate).

Specifies the TLS certificate that identifies this DataSource. When this DataSource initiates a TLS connection with a peer, this certificate plays the role of the 'client certificate'. When this DataSource accepts a TLS connection from a peer, this certificate plays the role of the 'server certificate'.

  • DataSource C: datasrc-ssl-present-certificate specifies the path to and filename of the certificate file in PEM format.

  • DataSource Java: datasrc-ssl-present-certificate specifies the alias for a certificate held in the Java KeyStore file specified by datasrc-ssl-keystore.

Overridden by add-peer:ssl-present-certificate for specific peer connections.

The directory path can contain the following substitution parameters:

Token Description

%r

This DataSource’s application-root

%a

This DataSource’s application-name

The DataSource Application won’t start if SSL is enabled (see datasrc-ssl-enable) and datasrc-ssl-present-certificate doesn’t point to a valid certificate.

Use in: C, Java

Syntax:

C DataSource applications
datasrc-ssl-present-certificate <path-to-ssl-certificate-pem-file>
Java DataSource applications
datasrc-ssl-present-certificate <ssl-certificate-alias-in-java-keystore>

Type: string

Default value: none

datasrc-ssl-cipherlist

datasrc-ssl-cipherlist configures the SSL/TLS ciphers supported by the DataSource for secure communications with its peers. You should configure this item in conjunction with datasrc-ssl-options, and review both regularly as part of your security policy.

In C-based DataSource applications, this configuration item takes one value: an OpenSSL cipher list. For a description of the cipher list format, see Cipher List Format on the OpenSSL website.

In Java-based DataSource applications, the ciphers are provided by the SunJSSE provider (com.sun.net.ssl.internal.ssl.Provider) bundled with the JVM. For a detailed list of the available ciphers and enabled ciphers in Java 8, see the documentation for the SunJSSE provider in Java Cryptography Architecture Oracle Providers Documentation for JDK 8.

To successfully establish an SSL connection, the SSL client and the SSL server must have at least one enabled cipher in common.

This item is overridden for a specific peer connection by the ssl-cipherlist option of add-peer.

Use in: C, Java

Syntax:

  • C: datasrc-ssl-cipherlist <cipher>[:<cipher>]…​

  • Java: datasrc-ssl-cipherlist <cipher>[,<cipher>]…​

Type: string

Default value:

datasrc-ssl-keystore

datasrc-ssl-keystore specifies the path to and filename of the Java KeyStore (JKS). The KeyStore contains the SSL certificate that this DataSource presents to connecting peers, copies of certificates used for certificate pinning, and the SSL private key used to decrypt the symmetric session key received from a DataSource peer. The KeyStore must be in Java JKS Format.

For more about certificate pinning, see the Wikipedia article at https://en.wikipedia.org/wiki/Certificate_pinning#Certificate_pinning

The directory path can contain the following substitution parameters:

Token Description

%r

This DataSource’s application-root

%a

This DataSource’s application-name

The Java DataSource application will throw an exception if SSL is enabled (datasrc-ssl-enable is TRUE) and you haven’t specified a Java KeyStore.

The equivalent configuration items in C-based DataSource applications (including Liberator and Transformer) are datasrc-ssl-present-certificate and datasrc-ssl-privatekey.

Use in: Java

Syntax: datasrc-ssl-keystore <keystore-file-path-and-name>

Type: string

Default value: [none]

datasrc-ssl-passwordfile

datasrc-ssl-passwordfile specifies the path to and filename of a password file containing a plain text (unencrypted) password used to access private key files, certificate files and KeyStores.

In a C-based DataSource application, the password provides access to the password-protected private key file that’s defined by datasrc-ssl-privatekey. (Also see the ssl-passwordfile option of add-peer.)

In a Java-based DataSource application, the password provides access to the Java KeyStore defined by datasrc-ssl-keystore, and hence to the private key/certificate pairs that are held inside the KeyStore.

If the Java keystore or private key file is encrypted with a password and datasrc-ssl-passwordfile isn’t defined, then the DataSource application exits in error.

We strongly recommend that you password protect your private key files and Java KeyStores.

Use in: C, Java

Syntax: datasrc-ssl-passwordfile <path-to-password-file>

Type: string

Default value: [none]

datasrc-ssl-privatekey

datasrc-ssl-privatekey specifies the path to and filename of the SSL private key that this DataSource application uses to decrypt the symmetric session key received from a DataSource peer. The file must be in PEM format.

Use this configuration item in a C-based DataSource application that acts as an SSL server (that is, it accepts incoming SSL connections from peers).

The directory path can contain the following substitution parameters:

Token Description

%r

This DataSource’s application-root

%a

This DataSource’s application-name

If this DataSource application initiates the Secure Sockets Layer (SSL) connection to a peer, then set the ssl-privatekey option of the add-peer entry for the connection.

The equivalent configuration in Java DataSource applications is datasrc-ssl-keystore.

Use in: C

Syntax: datasrc-ssl-privatekey <PEM-file-path-and-name>

Type: string

Default value: [none] In a C-based Datasource application, if SSL is enabled (datasrc-ssl-enable is TRUE), you must specify a datasrc-ssl-privatekey.

datasrc-ssl-ssloptions

datasrc-ssl-ssloptions specifies the levels of the SSL protocol that are supported for SSL connections used by this DataSource application.

Use in: C, Java

Syntax: datasrc-ssl-ssloptions <supported-SSL-levels>

Type: string

Default value:

  • C: SSL_OP_NO_SSLv2|SSL_OP_NO_SSLv3|SSL_OP_NO_TLSv1 (from DataSource 7)

  • Java: TLS

Values accepted:

For C-based DataSource applications:

Value Meaning

SSL_OP_ALL

Enable all of OpenSSL’s workarounds for known bugs in client implementations of SSL. For the full list of workarounds enabled by this option, see SSL_CTX_set_options on the OpenSSL website.

SSL_OP_NO_SSLv2

Disable support for SSLv2.

SSL_OP_NO_SSLv3

Disable support for SSLv3.

SSL_OP_NO_TLSv1

Disable support for TLSv1.

SSL_OP_NO_TLSv1_1

Disable support for TLSv1.1.

SSL_OP_NO_TLSv1_2

Disable support for TLSv1.2.

SSL_OP_NO_TLSv1_3

Disable support for TLSv1.3.

SSL_OP_CIPHER_SERVER_PREFERENCE

In a TLS handshake, the TLS client presents the DataSource with a list of the ciphers it supports in priority order, and the DataSource chooses a cipher from the list.

By default, and in accordance with the TLS specification, the DataSource chooses the client’s most preferred cipher from the ciphers they have in common.

When SSL_OP_CIPHER_SERVER_PREFERENCE is set, the DataSource chooses its most preferred cipher from the ciphers they have in common. This breaks with the TLS specification.

The DataSource’s cipher preferences are determined by the order of ciphers in datasrc-ssl-cipherlist. Ciphers are listed in descending order of preference, most preferred cipher first.

Available from DSDK 7.1.25.

You can specify multiple values using the | operator. In the example below, support for SSLv2, SSLv3, and TLSv1 has been disabled:

datasrc-ssl-options SSL_OP_NO_SSLv2|SSL_OP_NO_SSLv3|SSL_OP_NO_TLSv1

For Java-based DataSource applications (built under Java Platform Standard Edition 7), see the Protocols section of Java Cryptography Architecture Oracle Providers Documentation for JDK 8.

datasrc-ssl-port

datasrc-ssl-port specifies the network port to listen on for Secure Sockets Layer (SSL) connection requests from DataSource peers. The default of 0 means that no SSL connections can be made to this DataSource application.

Use in: C, Java

Syntax: datasrc-ssl-port <SSL-port-number>

Type: integer

Default value: 0 (No SSL connections can be made.)

ssl-config-name

ssl-config-name specifies the path to and filename of the OpenSSL configuration file that’s loaded by this DataSource application. One use for such a file is to allow the application access to a global trust store.

Use in: C

Syntax: ssl-config-name <openssl-config-file-path-and-name>

Type: string

Default value: NULL (no file provided)

ssl-debug

ssl-debug enables SSL debugging output for secure DataSource peer connections. The SSL handshake details are written to stderr and, from Platform 6.2 onwards, as DEBUG level entries in this DataSource application’s event log.

ssl-debug does not enable debugging output for Liberator’s secure RTTP interfaces: HTTPS and secure direct connections.

Use in: C

Syntax: ssl-debug <boolean>

Type: boolean

Default value: FALSE

ssl-engine-flags

ssl-engine-flags specifies the OpenSSL engine flags that are to be passed to the ENGINE implementation at run time.

Use in: C

Syntax: ssl-engine-flags flag1|flag2|flag3|…​

Type: string

Default value: [ENGINE use is disabled]

Values accepted:

Flag Description

dh

Limit engine usage to DH operations only

dsa

Limit engine usage to DSA operations only

rand

Limit engine usage to random operations only

rsa

Limit engine usage to RSA operations only

all

Allow OpenSSL to use any of the above operations

Use the | operator to specify multiple flag values. For example, to allow the engine to use both dsa and rsa operations, specify:

ssl-engine-flags dsa|rsa

ssl-engine-id

ssl-engine-id specifies the OpenSSL ENGINE cryptographic module to be used. OpenSSL has built-in support for cryptographic acceleration. An application can get a reference to a specific representation, often a hardware device. These representations are referred to as ENGINES. For more about this, see engine on the OpenSSL website.

The default value of openssl, or the value software, prevent the DataSource application from attempting to use an SSL card. If you set the value all, the application attempts to find and use any SSL cards available on the machine. Any other value is considered to represent a specific SSL card - please refer to the OpenSSL documentation for a full list of what’s supported.

Use in: C

Syntax: ssl-engine-id <ENGINE-module-name>

Type: string

Default value: openssl (The engine uses the normal built-in Open SSL software functions rather than a hardware device.)

ssl-random-seed

ssl-random-seed overrides OpenSSL’s automatic seeding of its pseudo random number generator (PRNG) by providing an explicit source of random data with which to seed the PRNG.

On Linux, the OpenSSL PRNG is automatically seeded from the non-blocking device file /dev/urandom. On Microsoft Windows, the PRNG is automatically seeded from CryptGenRandom and other sources of entropy. Source: Random Numbers: Seeds on the OpenSSL Wiki.

If the standard sources of entropy used to automatically seed OpenSSL’s PRNG do not comply with your organisation’s security policy, ssl-random-seed provides you with the flexibility to seed OpenSSL’s PRNG with a specific source of entropy.

Use in: C

Syntax: ssl-random-seed <source> [<path>] [<bytes>]

<source> Description

builtin

Seed the PRNG from /dev/urandom on Linux or CryptGenRandom and other sources of entropy on Microsoft Windows. Arguments path and bytes are ignored.

file

Uses the first <bytes> bytes of the data in the file <path> to seed the PRNG. If the path to the file is relative, the path is relative to the DataSource application’s root directory.

exec

Uses the first <bytes> bytes of the output from the command specified in <path> to seed the PRNG. If the path to the command is relative, the path is relative to the DataSource application’s root directory.

Type: string

Default value: builtin

Examples

  • ssl-random-seed builtin

  • ssl-random-seed file /dev/hwrng 1024


See also: