I offer to port the headers (for static libraries and/or dynamic libraries)
for the most basic/important functions (as a start) in OpenSSL [>=1.0.2]
(like: hashes, aes crypto, big numbers, ssl/tls)
I can also write or port some tests/examples/how-to-use samples.
OpenSSL can be easily compiled for windows/linux/mac/android - x32/x64 (and it seems that it can be compiled with djgpp for DOS)
so it's going to be multiplatform.