If necessary, a write function will negotiate a TLS/SSL session, if not already
explicitly performed by L<SSL_connect(3)> or L<SSL_accept(3)>. If the peer
requests a re-negotiation, it will be performed transparently during
-the write functio operation. The behaviour of the write functions depends on the
+the write function operation. The behaviour of the write functions depends on the
underlying BIO.
For the transparent negotiation to succeed, the B<ssl> must have been
before the first call to a write function.
If the underlying BIO is B<blocking>, the write functions will only return, once
-the write operation has been finished or an error occurred, except when a
-renegotiation take place, in which case a SSL_ERROR_WANT_READ may occur.
-This behaviour can be controlled with the SSL_MODE_AUTO_RETRY flag of the
-L<SSL_CTX_set_mode(3)> call.
+the write operation has been finished or an error occurred.
If the underlying BIO is B<non-blocking> the write functions will also return
when the underlying BIO could not satisfy the needs of the function to continue
When a write function call has to be repeated because L<SSL_get_error(3)>
returned B<SSL_ERROR_WANT_READ> or B<SSL_ERROR_WANT_WRITE>, it must be repeated
with the same arguments.
+The data that was passed might have been partially processed.
+When B<SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER> was set using L<SSL_CTX_set_mode(3)>
+the pointer can be different, but the data and length should still be the same.
-When calling the write functions with num=0 bytes to be sent the behaviour is
-undefined.
+You should not call SSL_write() with num=0, it will return an error.
+SSL_write_ex() can be called with num=0, but will not send application data to
+the peer.
=head1 RETURN VALUES
=back
+=head1 HISTORY
+
+SSL_write_ex() was added in OpenSSL 1.1.1.
+
=head1 SEE ALSO
L<SSL_get_error(3)>, L<SSL_read_ex(3)>, L<SSL_read(3)>