Botan is a C++11 library for crypto and TLS released under the permissive
2-clause BSD license (see doc/license.txt for the specifics).
For all the details on building the library read doc/manual/building.rst,
but basically:
$ configure.py --help $ configure.py [probably some options] $ make $ ./botan-test # test output $ ./botan # shows available commands $ make install
You can file bugs at https://github.com/randombit/botan/issues/ or by sending a report to the botan-devel mailing list
The github wiki is also available as a resource.
Kullo GmbH hosts a CI building botan on Linux, OS X, and Windows at https://botan-ci.kullo.net/