The changes made in this file are detailed in release/3.5 commits
1f30c8943b through 92c04c6b9d inclusive.
Some slight alterations are necessary; librb instead of libratbox,
snprintf() instead of rb_snprintf(), etc. Also, release/4 has
offline certificate digesting functionality. For more insight,
simply diff the openssl.c between release/3.5 and release/4.