crypt_sha256/crypt_sha512, fix build with more recent versions of cla…

[devnexen]

…ng (> 11).

clang picks up the address subtraction to null as UB, but the implementations
are based on glibc.

error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction] if ((key - (char *) 0) % __alignof__ (uint64_t) != 0) {

[Girgias]

I noticed this warning when compiling with Clang but I'm not sure how to fix it and if pragmas are desirable, and because this is security related code I'm far from confident to touch it, so I suppose the pragmas are OK

[devnexen]

Yes since it s well based on the glibc implementation, I did not want to touch it neither.

[cmb69]

Undefined behavior is a serious issue, and I don't think we should suppress such warnings, if they are legit, and I think in this case they are.

Instead of subtracting a NULL pointer, shouldn't we just cast to uintptr_t?

[devnexen]

Undefined behavior is a serious issue, and I don't think we should suppress such warnings, if they are legit, and I think in this case they are.

Instead of subtracting a NULL pointer, shouldn't we just cast to uintptr_t?

It appears even tough the related glibc code had been like this forever (even now). Ok will give a try then.

[Girgias]

Where the PHPDBG changes present in the previous PR as well?

[devnexen]

Nope :-)

[cmb69]

@devnexen, there have been some issues with the branches, and apparently this fix is no longer in "master" now. I assume it should be applied there as well, but you had reverted. Do we need to re-apply?

[devnexen]

Yes I redid a new PR just for master