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Related, hardbool, it seems gcc can automatically handle this soon.

https://blog.adacore.com/adacore-enhances-gcc-security-with-... and https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.ht...

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Not exactly; these constants in sudo are an enum of sorts (actually preprocessor macros). It's not just bool (and won't just be bool in many situations). It is cool to see GCC exploring automatic protection in this space; I just don't think it is relevant to what sudo did here.

Hardbool lets you use custom true and false representations with higher hamming distances. The sudo patch uses custom representations for their enum that have higher hamming distances. The only difference is that hardbool is for true/false and this patch is for AUTH_SUCCESS/AUTH_FAILURE/AUTH_ERROR etc. But that's irrelevant. It's the exact same technique.

> The only difference is that hardbool is for true/false and this patch is for AUTH_SUCCESS/AUTH_FAILURE/AUTH_ERROR etc. But that's irrelevant.

It's very relevant! The problematic comparison in this code isn't true/false! A feature that only protects true/false does not help here.

Couldn't you combine bools for bitwise masks to get this?

Define the enum to be represented as a two's complement integer made of hardbools.

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