protocol correctness, OpenSSL-compat hardening, and sensitive-memory zeroization #7864

Job	Run time
make check (--verbose --enable-all --disable-all-osp --disable-opensslall --enable-opensslcoexist...	2m 25s
make check (--verbose --enable-all --disable-all-osp --disable-opensslall --enable-opensslcoexist...	2m 30s
	4m 55s

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