Configure Security Protocols and Cipher Suites for Blast Secure Gateway (BSG)

You can configure the security protocols and cipher suites that BSG's client-side listener accepts by editing the file absg.properties.

The protocols that are allowed are, from low to high, tls1.0, tls1.1, and tls1.2. Older protocols such as SSLv3 and earlier are never allowed. Two properties, localHttpsProtocolLow and localHttpsProtocolHigh, determine the range of protocols that the BSG listener will accept. For example, setting localHttpsProtocolLow=tls1.0 and localHttpsProtocolHigh=tls1.2 will cause the listener to accept tls1.0, tls1.1, and tls1.2. The default settings are localHttpsProtocolLow=tls1.2 and localHttpsProtocolHigh=tls1.2, meaning that by default only TLS 1.2 is allowed. You can examine the BSG's absg.log file to discover the values that are in force for a specific BSG instance.

You must specify the list of ciphers using the format that is defined in OpenSSL. You can search for openssl cipher string in a web browser and see the cipher list format. The following cipher list is the default:

ECDHE+AESGCM

Note: In FIPS mode, only GCM cipher suites are enabled (ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256).

Procedure

1. On the connection broker instance, edit the file install_directory\<name>\View\Server\appblastgateway\absg.properties.

   By default, the install directory is %ProgramFiles%.

2. Edit the properties localHttpsProtocolLow and localHttpsProtocolHigh to specify a range of protocols.

   For example,

   localHttpsProtocolLow=tls1.0
   localHttpsProtocolHigh=tls1.2
   

   To enable only one protocol, specify the same protocol for both localHttpsProtocolLow and localHttpsProtocolHigh.

3. Edit the localHttpsCipherSpec property to specify a list of cipher suites.

   For example,

   localHttpsCipherSpec=!aNULL:kECDH+AESGCM:ECDH+AESGCM:kECDH+AES:ECDH+AES
   

4. Restart the Windows service Horizon Blast Secure Gateway.