commit e3c0d76bc7848aae01fe9a86720d435b999f3bc1
author Matt Caswell <matt@openssl.org> Fri Jun 30 09:41:03 2017 +0100
committer Matt Caswell <matt@openssl.org> Fri Jul 07 16:08:05 2017 +0100
tree 7b4e014eee678d04c4bef40ccfa1da623a5c6009
parent 515982154031b679f58d5e2cbd7752294779221e

Do not allow non-dhe kex_modes by default

Allow that mode to be configured if desired.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3833)

ssl/statem/extensions_srvr.c

diff --git a/ssl/statem/extensions_srvr.c b/ssl/statem/extensions_srvr.c
index 3da9f55..7f30ac7 100644
--- a/ssl/statem/extensions_srvr.c
+++ b/ssl/statem/extensions_srvr.c
@@ -477,7 +477,8 @@
     while (PACKET_get_1(&psk_kex_modes, &mode)) {
         if (mode == TLSEXT_KEX_MODE_KE_DHE)
             s->ext.psk_kex_mode |= TLSEXT_KEX_MODE_FLAG_KE_DHE;
-        else if (mode == TLSEXT_KEX_MODE_KE)
+        else if (mode == TLSEXT_KEX_MODE_KE
+                && (s->options & SSL_OP_ALLOW_NO_DHE_KEX) != 0)
             s->ext.psk_kex_mode |= TLSEXT_KEX_MODE_FLAG_KE;
     }
 #endif