I intend to implement SHA-1 and SHA-256 in the same plugin. I'll first have to get the md5 different outputs to correctly work and then implement the other.
It should end as a multi-algorithms Hash plugin.
Just a heads up: the plugin ID in edittime.js GetPluginSettings() is currently "MD5". You can change all the other settings at any time, but the ID is the string C2 uses to identify your plugin. If you change the ID from "MD5" to something else, all existing projects using the plugin will no longer load, since C2 will consider it a different plugin.
Basically, try to choose the correct ID string when starting a plugin, and then never change it, or you might end up breaking lots of projects. Since the only public version is broken, I guess now is a good time to set it to "Hash" or whatever :)