recv_into() shares read()'s error-mapping pattern and inherited the
same omission: wolfSSL_read returning WOLFSSL_ERROR_WANT_WRITE (during
a renegotiation needing a write) was reported as a generic SSLError
instead of SSLWantWriteError, breaking non-blocking callers that
distinguish readiness directions. Add the WANT_WRITE branch.
wolfSSL_read can return WOLFSSL_ERROR_WANT_WRITE when the SSL layer
must flush a handshake record (e.g. renegotiation) before returning
data. read() only handled WANT_READ, raising a generic SSLError
otherwise, which stops non-blocking callers from select()-ing on
writability. Add a WANT_WRITE branch raising SSLWantWriteError.
wolfSSL_write can return WOLFSSL_ERROR_WANT_READ (e.g. during a
renegotiation that must read a record before progressing; secure
renegotiation is enabled by default). write() only handled WANT_WRITE,
so WANT_READ fell through to a generic SSLError and non-blocking
callers tore the session down. Add a WANT_READ branch raising
SSLWantReadError, matching do_handshake().
Kareem
Juliusz Sosinowicz