Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/11816)
(cherry picked from commit
e0bcb4f97f7496af032013ead15b7472b60e85fa)
check to see if a callback has been set via SSL_CTX_set_psk_client_callback() or
SSL_set_psk_client_callback() and use that. In this case the B<hint> value will
always be NULL and the handshake digest will default to SHA-256 for any returned
-PSK.
+PSK. TLSv1.3 early data exchanges are possible in PSK connections only with the
+B<SSL_psk_use_session_cb_func> callback, and are not possible with the
+B<SSL_psk_client_cb_func> callback.
=head1 NOTES
and it will use that in preference. If no such callback is present then it will
check to see if a callback has been set via SSL_CTX_set_psk_server_callback() or
SSL_set_psk_server_callback() and use that. In this case the handshake digest
-will default to SHA-256 for any returned PSK.
+will default to SHA-256 for any returned PSK. TLSv1.3 early data exchanges are
+possible in PSK connections only with the B<SSL_psk_find_session_cb_func>
+callback, and are not possible with the B<SSL_psk_server_cb_func> callback.
=head1 NOTES