Passing two values to custom validation

[eluser]Unknown[/eluser]
Hi,

was just looking at some validation code I have on a login form, and it seemed like it could be cool to test whether the login/password combination provided was valid, and I wanted to do this inside a custom validation callback.

Any clever ways of doing this that spring to mind? It's a security-light internal thing so I don't want to install and configure auth packages just for this.

thanks
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