- introduce lib/tls/mbedtls lib/tls/openssl
- move wrapper into lib/tls/mbedtls/wrapper
- introduce private helpers to hide backend
This patch doesn't replace or remove the wrapper, it moves it
to lib/tls/mbedtls/wrapper.
But it should be now that the ONLY functions directly consuming
wrapper apis are isolated in
- lib/tls/mbedtls/client.c (180 lines)
- lib/tls/mbedtls/server.c (317 lines)
- lib/tls/mbedtls/ssl.c (325 lines)
In particular there are no uses of openssl or mbedtls-related
constants outside of ./lib/tls any more.
This defines the OpenSSL X509_CHECK_FLAG_...s and the set/clear
accessors. Since none of them are supported, the set / clear
accessor always does nothing and returns error.
This adds the standard OpenSSL api to get a pointer to the SSL struct's
X509_VERIFY_PARAM. We need this for the OpenSSL api to set the peer
hostname introduced in the next patch.
