CVSROOT: /cvs
Module name: src
Changes by: t...@cvs.openbsd.org 2021/09/10 03:25:29
Modified files:
lib/libssl : ssl.h ssl_err.c ssl_tlsext.c
lib/libssl/man : SSL_CTX_set_alpn_select_cb.3
Log message:
Do not ignore SSL_TLSEXT_ERR_FATAL from the ALPN callback
As reported by Jeremy Harris, we inherited a strange behavior from
OpenSSL, in that we ignore the SSL_TLSEXT_ERR_FATAL return from the
ALPN callback. RFC 7301, 3.2 states: 'In the event that the server
supports no protocols that the client advertises, then the server
SHALL respond with a fatal "no_application_protocol" alert.'
Honor this requirement and succeed only on SSL_TLSEXT_ERR_{OK,NOACK}
which is the current behavior of OpenSSL. The documentation change
is taken from OpenSSL 1.1.1 as well.
As pointed out by jsing, there is more to be fixed here:
- ensure that the same protocol is selected on session resumption
- should the callback be called even if no ALPN extension was sent?
- ensure for TLSv1.2 and earlier that the SNI has already been processed
ok beck jsing
