* Add rerun-if-env-changed instructions for BORING_* variables
* Use X509_get0_notBefore() and X509_get0_notAfter() instead of X509_getm_notBefore() and X509_getm_notAfter().
According to
https://www.openssl.org/docs/man1.1.0/man3/X509_getm_notBefore.html,
"X509_getm_notBefore() and X509_getm_notAfter() are similar to
X509_get0_notBefore() and X509_get0_notAfter() except they return
non-constant mutable references to the associated date field of the
certificate".
* Only update boringssl submodule if BORING_BSSL_PATH not provided
* Allow BORING_BSSL_LIB_PATH to control link search
* Add fips feature
* Use X509_set_notAfter unconditionally for FIPS compatibility
This is equivalent according to
https://boringssl.googlesource.com/boringssl/+/c947efabcbc38dcf93e8ad0e6a76206cf0ec8072
The version of boringssl that's FIPS-certified doesn't have `X509_set1_notAfter`.
The only difference between that and `X509_set_notAfter` is whether they're const-correct,
which doesn't seem worth having two different code-paths.
* Check out fips commit automatically
* Verify the version of the compiler used for building boringssl
NIST specifies that it needs to be 7.0.1; I originally tried building with clang 10 and it failed.
Theoretically this should check the versions of Go and Ninja too, but they haven't given me trouble in practice.
Example error:
```
Compiling boring-sys v1.1.1 (/home/jnelson/work/boring/boring-sys)
error: failed to run custom build command for `boring-sys v1.1.1 (/home/jnelson/work/boring/boring-sys)`
Caused by:
process didn't exit successfully: `/home/jnelson/work/boring/target/debug/build/boring-sys-31b8ce53031cfd83/build-script-build` (exit status: 101)
--- stdout
cargo:rerun-if-env-changed=BORING_BSSL_PATH
--- stderr
warning: missing clang-7, trying other compilers: Permission denied (os error 13)
warning: FIPS requires clang version 7.0.1, skipping incompatible version "clang version 10.0.0-4ubuntu1 "
thread 'main' panicked at 'unsupported clang version "cc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0": FIPS requires clang 7.0.1', boring-sys/build.rs:216:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
* Add Github actions workflow testing FIPS
Co-authored-by: Joshua Nelson <jnelson@cloudflare.com>
I'm not quite sure why these are unsafe traits, probably to prevent
implementing them for random types accidentally. However, Clippy
demands a "# Safety" section in their docs. Tell it to get lost.
Rushil Mehra