Fix `staticcheck` issues:
- S1028 use `fmt.Errorf` to construct formatted errors
- ST1017 yoda conditions
- ST1005 error message capitalization
- ST1006 avoid `self` as receiver name
- S1030 use `buf.String`
- S1011 avoid redundant loop when `append` suffices
- SA4006 unused value
- S1019 remove redundant capacity on `make` call
- SA2002 `t.Fatal` called outside of test
Exported error violates ST1012, which is ignored by this PR since rename may cause breaking changes.
Remove redundant parentheses wrapping, and use CamelCase naming while at it.
- created a uniform shim layer for the Go code to invoke that does the
right thing depending on the version of openssl. functions that have
yet to be moved can be done so as needed.
- fixed the incorrect use of X509_STORE_CTX_get_app_data in verify_cb to
pull out the SSL object from the x509 store context, which causes
crashes when the SSL object index happens to not be zero.
- fix engine not being passed to HMAC_Init_ex
- fix HMAC tests not checking for failures with NewHMAC
