diff options
Diffstat (limited to 'lib/libssl/ssl_tlsext.c')
| -rw-r--r-- | lib/libssl/ssl_tlsext.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/lib/libssl/ssl_tlsext.c b/lib/libssl/ssl_tlsext.c index 4cb7c5bf905..a0e2f7320bd 100644 --- a/lib/libssl/ssl_tlsext.c +++ b/lib/libssl/ssl_tlsext.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssl_tlsext.c,v 1.62 2020/02/18 16:12:14 tb Exp $ */ +/* $OpenBSD: ssl_tlsext.c,v 1.63 2020/04/21 17:06:16 jsing Exp $ */ /* * Copyright (c) 2016, 2017, 2019 Joel Sing <jsing@openbsd.org> * Copyright (c) 2017 Doug Hogan <doug@openbsd.org> @@ -1288,13 +1288,27 @@ tlsext_keyshare_server_parse(SSL *s, CBS *cbs, int *alert) return 0; /* - * XXX support other groups later. - * XXX enforce group can only appear once. + * XXX - check key exchange against supported groups from client. + * XXX - check that groups only appear once. */ - if (S3I(s)->hs_tls13.key_share == NULL || - tls13_key_share_group(S3I(s)->hs_tls13.key_share) != group) + + /* + * Ignore this client share if we're using earlier than TLSv1.3 + * or we've already selected a key share. + */ + if (S3I(s)->hs_tls13.max_version < TLS1_3_VERSION) + continue; + if (S3I(s)->hs_tls13.key_share != NULL) continue; + /* XXX - consider implementing server preference. */ + if (!tls1_check_curve(s, group)) + continue; + + /* Decode and store the selected key share. */ + S3I(s)->hs_tls13.key_share = tls13_key_share_new(group); + if (S3I(s)->hs_tls13.key_share == NULL) + goto err; if (!tls13_key_share_peer_public(S3I(s)->hs_tls13.key_share, group, &key_exchange)) goto err; |