This is a copy of the original libsrp written by Tom Wu (creator of SRP) but with all the extraneous things you don't need like NIS and PAM integration. It does not alter the code to his library except for fixing a few minor bugs in output formatting of hex codes and creating a "srp_simple.c" file that simplifies using the SRP6a protocol.
It also doesn't have all of the previous versions of SRP since those are known to be vulnerable.
Just the usual ./configure && make && make install
It will put a libsrp.a file in /usr/local/lib for you to use.
Take a look at srp6bench for how to use the base API.
Look at srp_simple.c for a simplification layer that does most of what you probably want to do using only HEX encoded strings for everything. This library is for easier use with scripting languages that can't handle complex binary blob types or C structs. It also helps to get the encodings right since it's only giving you properly HEX encoded values.
Base64 wasn't used because after numerous attempts to use it with various languages I found that Base64 is too variable, and that HEX encoded strings were the most reliable and easiest to debug.
Finally, look in simple_test.c for an example of using the srp_simple.c layer.
For whatever idiotic reason Apple decided to deprecate all of OpenSSL. You'll get deprecation warnings, and you should just ignore them until there's a better explanation as to why and a proper workaround that doesn't involve rewriting everything to use Apple's libraries.