openbsd/src
1
0
Fork 0
mirror of https://github.com/openbsd/src.git synced 2026-06-17 23:03:29 +02:00
Code Activity

Send illegal parameter alerts for various HelloRetryRequest violations.

Browse Source 
Be more RFC compliant and send illegal parameter alerts when the client
receives a HelloRetryRequest that requests a group that we did not offer
or a group that we sent a key share for in the ClientHello. These were
annotated as missing, but not previously implemented.

Prompted by a report from the tlspuffin team.

ok tb@
This commit is contained in:
jsing
2026-06-14 14:53:07 +00:00
parent 9fa1dce37a
commit aca74d656c
1 changed files with 10 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/libssl/tls13_client.c
+10 -6
View File
@@ -1,4 +1,4 @@
/* $OpenBSD: tls13_client.c,v 1.106 2025/12/04 21:16:17 beck Exp $ */
/* $OpenBSD: tls13_client.c,v 1.107 2026/06/14 14:53:07 jsing Exp $ */
/*
* Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
*
@@ -450,12 +450,16 @@ tls13_client_hello_retry_send(struct tls13_ctx *ctx, CBB *cbb)
/*
* Ensure that the server supported group is one that we listed in our
* supported groups and is not the same as the key share we previously
* offered.
* offered. See RFC 8446 section 4.2.8.
*/
if (!tls1_check_group(ctx->ssl, ctx->hs->tls13.server_group))
return 0; /* XXX alert */
if (ctx->hs->tls13.server_group == tls_key_share_group(ctx->hs->key_share))
return 0; /* XXX alert */
if (!tls1_check_group(ctx->ssl, ctx->hs->tls13.server_group)) {
ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
return 0;
}
if (ctx->hs->tls13.server_group == tls_key_share_group(ctx->hs->key_share)) {
ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
return 0;
}
/* Switch to new key share. */
tls_key_share_free(ctx->hs->key_share);