Add support for OpenSSL, mbedTLS 2 and mbedTLS 3

Brings the previous OpenSSL implementation into src/IO/tls_openssl.c.

Now, the TLS functions have the implementation name as prefix, like
a_Tls_openssl_connect().

The generic interface at IO/tls.h hides the implementation which is
selected at configure time. The appropriate functions of that
implementation are called from IO/tls.c to IO/tls_<impl>.c. In this way,
support for more TLS libraries can easily be added.

In the case of mbedTLS, there are some incompatible changes from version
2 to 3, so we use some ifdefs to fix the differences.

0 files changed, 0 insertions, 0 deletions