Commerce support for Spanish banks that use Sermepa/Redsys systems.
Full list of banks managed by sermepa: http://www.servired.es/espanol/miembros.htm
Both methods GET and POST are supported in the stable version.
Install the Commerce Sermepa module.
Enable the Rule for Sermepa via Store > Configuration > Payment settings and edit the rule settings to set the information that provided by your bank office.
You can set the mode of the module to Test or Live.