Errors that refer to a bunch of unresolved OpenSSL symbols that clearly exist?
The problem was caused by the order of the libraries in the link command. Switching the order of libcrypto.a and libssl.a resolved all of the symbols.
GCC uses LD by default, and its a single pass linker. When you have two libraries, like libssl and libcrypto linked in a particular order, it means libssl depends on symbols from libcrypto. Therefore, libssl must precede libcrypto (or libcrypto must follow libssl). It should be no surprise libssl relies upon libcrypto since libcrypto provides the crypto used by libssl.