Spring Security: IP Address Whitelist Before Deferring to HTTP Basic Auth

I have a single URL accessible through a servlet that I have locked down using Spring Security's DaoAuthenticationProvider. I now have the requir开发者_StackOverflow社区ement that certain incoming IP addresses must be whitelisted and so are not requested to authenticate.

I can hack around this easily enough by overriding DaoAuthenticationProvider's authenticate method and bypassing the superclasses's implementation if the IP address matches a known IP address but this then only works when the sender of the request supplies a username and password (even if it's nonsense). Otherwise the provider doesn't get called.

What would be the best way to do this? Should I be using a filter to bypass the authentication procedure if a known IP address is incoming?

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Could you just use the hasIpAddress() expression? We're doing that for what appears to be a similar case.

    <security:intercept-url pattern="/services/**" access="hasIpAddress('192.168.1.0/24')"/>

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I think the idiomatic Spring Security way to do it is to implement a pre-authentication filter that would populate security context with a valid Authentication object when client is in the whitelist. You can implement such a filter from scratch (for example, as here) or use AbstractPreAuthenticatedProcessingFilter (though it seems to be overcomplicated for your task).