File containing random data for HTTPS support

WTSupported in traditional Synergy on Windows
WNSupported in Synergy .NET on Windows
USupported on UNIX
VSupported on OpenVMS

The HTTP_RAND environment variable specifies a file that contains random data.


The path and name of a text file or an entropy‑gathering device (if available on your system).


When the Synergy HTTP document transport API initializes HTTPS support, it uses random data to ensure that the data is secure, because random data helps prevent hackers from guessing patterns. For most systems, this random data can be gathered from recognized system entropy devices or from the screen itself, or from a temporary file filled with random logic. However, on some systems, these methods are not enough, and a “Cannot load random state” error is generated. To eliminate this error, you can define the HTTP_RAND environment variable to point at a file that will be used (as a last resort) to gather random data when the HTTPS system is initialized.

Setting location

The environment. On Windows, this environment variable can also be set in the [synergy], [dbr], or [myprog] section of synergy.ini (where myprog is any .dbr file).

Used by

Synergy HTTP document transport API

See also

Synergy HTTP Document Transport API


On Windows,

set HTTP_RAND=c:\windows\random.txt


HTTP_RAND=/etc/entropy   ;export HTTP_RAND