diff options
| author | Matt Caswell <matt@openssl.org> | 2017-06-30 09:41:03 +0100 |
|---|---|---|
| committer | Matt Caswell <matt@openssl.org> | 2017-07-07 16:08:05 +0100 |
| commit | e3c0d76bc7848aae01fe9a86720d435b999f3bc1 (patch) | |
| tree | 7b4e014eee678d04c4bef40ccfa1da623a5c6009 /ssl/statem/extensions_clnt.c | |
| parent | 515982154031b679f58d5e2cbd7752294779221e (diff) | |
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)
Diffstat (limited to 'ssl/statem/extensions_clnt.c')
| -rw-r--r-- | ssl/statem/extensions_clnt.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/ssl/statem/extensions_clnt.c b/ssl/statem/extensions_clnt.c index 0d1ca281f7..1bbb2102d7 100644 --- a/ssl/statem/extensions_clnt.c +++ b/ssl/statem/extensions_clnt.c @@ -503,30 +503,29 @@ EXT_RETURN tls_construct_ctos_supported_versions(SSL *s, WPACKET *pkt, } /* - * Construct a psk_kex_modes extension. We only have two modes we know about - * at this stage, so we send both. + * Construct a psk_kex_modes extension. */ EXT_RETURN tls_construct_ctos_psk_kex_modes(SSL *s, WPACKET *pkt, unsigned int context, X509 *x, size_t chainidx, int *al) { #ifndef OPENSSL_NO_TLS1_3 - /* - * TODO(TLS1.3): Do we want this list to be configurable? For now we always - * just send both supported modes - */ + int nodhe = s->options & SSL_OP_ALLOW_NO_DHE_KEX; + if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_psk_kex_modes) || !WPACKET_start_sub_packet_u16(pkt) || !WPACKET_start_sub_packet_u8(pkt) || !WPACKET_put_bytes_u8(pkt, TLSEXT_KEX_MODE_KE_DHE) - || !WPACKET_put_bytes_u8(pkt, TLSEXT_KEX_MODE_KE) + || (nodhe && !WPACKET_put_bytes_u8(pkt, TLSEXT_KEX_MODE_KE)) || !WPACKET_close(pkt) || !WPACKET_close(pkt)) { SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_PSK_KEX_MODES, ERR_R_INTERNAL_ERROR); return EXT_RETURN_FAIL; } - s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_KE | TLSEXT_KEX_MODE_FLAG_KE_DHE; + s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_KE_DHE; + if (nodhe) + s->ext.psk_kex_mode |= TLSEXT_KEX_MODE_FLAG_KE; #endif return EXT_RETURN_SENT; |