From 42995b3308983da3add7404dc736c3fcfaa2b90f Mon Sep 17 00:00:00 2001
From: beck <>
Date: Wed, 22 Jan 2020 02:21:05 +0000
Subject: Add minimal support for hello retry request for RFC conformance. We
currently don't support sending a modified clienthello
ok jsing@ tb@
---
src/lib/libssl/tls13_client.c | 65 ++++++++++++++++++++++++++++++++++++++++-
src/lib/libssl/tls13_internal.h | 3 +-
src/lib/libssl/tls13_lib.c | 5 +++-
src/lib/libssl/tls13_server.c | 9 +-----
4 files changed, 71 insertions(+), 11 deletions(-)
(limited to 'src')
diff --git a/src/lib/libssl/tls13_client.c b/src/lib/libssl/tls13_client.c
index 4ec29ea956..ed9a69918a 100644
--- a/src/lib/libssl/tls13_client.c
+++ b/src/lib/libssl/tls13_client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_client.c,v 1.22 2020/01/21 12:08:04 jsing Exp $ */
+/* $OpenBSD: tls13_client.c,v 1.23 2020/01/22 02:21:05 beck Exp $ */
/*
* Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
*
@@ -809,3 +809,66 @@ tls13_client_finished_sent(struct tls13_ctx *ctx)
return tls13_record_layer_set_write_traffic_key(ctx->rl,
&secrets->client_application_traffic);
}
+
+
+static int
+tls13_client_hello_retry_process(struct tls13_ctx *ctx, CBS *cbs)
+{
+ CBS server_random, session_id;
+ uint16_t cipher_suite, legacy_version;
+ uint8_t compression_method;
+ int alert_desc;
+ SSL *s = ctx->ssl;
+
+ if (!CBS_get_u16(cbs, &legacy_version))
+ goto err;
+ if (!CBS_get_bytes(cbs, &server_random, SSL3_RANDOM_SIZE))
+ goto err;
+ if (!CBS_get_u8_length_prefixed(cbs, &session_id))
+ goto err;
+ if (!CBS_get_u16(cbs, &cipher_suite))
+ goto err;
+ if (!CBS_get_u8(cbs, &compression_method))
+ goto err;
+
+ /*
+ * XXX currently this will change state and be hazardous later
+ * if we decide to support sending an updated client hello.
+ * however, since we will not today (and are going to return
+ * illegal parameter as per section 4.1.4) we just ensure
+ * that the extensions parse correctly.
+ */
+ if (!tlsext_client_parse(s, cbs, &alert_desc, SSL_TLSEXT_MSG_SH)) {
+ ctx->alert = alert_desc;
+ goto err;
+ }
+
+ if (CBS_len(cbs) != 0)
+ goto err;
+
+ /* XXX for now, just say no, we will not change our hello */
+ ctx->alert = SSL_AD_ILLEGAL_PARAMETER;
+ err:
+ if (ctx->alert == 0)
+ ctx->alert = TLS1_AD_DECODE_ERROR;
+ return 0;
+}
+
+int
+tls13_client_hello_retry_recv(struct tls13_ctx *ctx)
+{
+ int ret = 0;
+ CBS cbs;
+
+ if (!tls13_handshake_msg_content(ctx->hs_msg, &cbs))
+ goto err;
+
+ if (!tls13_client_hello_retry_process(ctx, &cbs)) {
+ if (ctx->alert == SSL_AD_ILLEGAL_PARAMETER)
+ tls13_set_errorx(ctx, TLS13_ERR_HRR_FAILED, 0,
+ "Unsatisfiable hello retry request", NULL);
+ goto err;
+ }
+err:
+ return ret;
+}
diff --git a/src/lib/libssl/tls13_internal.h b/src/lib/libssl/tls13_internal.h
index 7fee37f5dd..167ed1f254 100644
--- a/src/lib/libssl/tls13_internal.h
+++ b/src/lib/libssl/tls13_internal.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_internal.h,v 1.40 2020/01/22 01:02:28 jsing Exp $ */
+/* $OpenBSD: tls13_internal.h,v 1.41 2020/01/22 02:21:05 beck Exp $ */
/*
* Copyright (c) 2018 Bob Beck <beck@openbsd.org>
* Copyright (c) 2018 Theo Buehler <tb@openbsd.org>
@@ -38,6 +38,7 @@ __BEGIN_HIDDEN_DECLS
#define TLS13_IO_USE_LEGACY -4
#define TLS13_ERR_VERIFY_FAILED 16
+#define TLS13_ERR_HRR_FAILED 17
typedef void (*tls13_alert_cb)(uint8_t _alert_desc, void *_cb_arg);
typedef ssize_t (*tls13_phh_recv_cb)(void *_cb_arg, CBS *cbs);
diff --git a/src/lib/libssl/tls13_lib.c b/src/lib/libssl/tls13_lib.c
index bb749a9b68..e353e9fdad 100644
--- a/src/lib/libssl/tls13_lib.c
+++ b/src/lib/libssl/tls13_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_lib.c,v 1.17 2020/01/22 01:02:28 jsing Exp $ */
+/* $OpenBSD: tls13_lib.c,v 1.18 2020/01/22 02:21:05 beck Exp $ */
/*
* Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
* Copyright (c) 2019 Bob Beck <beck@openbsd.org>
@@ -353,6 +353,9 @@ tls13_legacy_error(SSL *ssl)
case TLS13_ERR_VERIFY_FAILED:
reason = SSL_R_CERTIFICATE_VERIFY_FAILED;
break;
+ case TLS13_ERR_HRR_FAILED:
+ reason = SSL_R_NO_CIPHERS_AVAILABLE;
+ break;
}
ERR_put_error(ERR_LIB_SSL, (0xfff), reason, ctx->error.file,
diff --git a/src/lib/libssl/tls13_server.c b/src/lib/libssl/tls13_server.c
index 541e341936..10d85a62b3 100644
--- a/src/lib/libssl/tls13_server.c
+++ b/src/lib/libssl/tls13_server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_server.c,v 1.3 2019/11/17 14:25:03 tb Exp $ */
+/* $OpenBSD: tls13_server.c,v 1.4 2020/01/22 02:21:05 beck Exp $ */
/*
* Copyright (c) 2019 Joel Sing <jsing@openbsd.org>
*
@@ -96,13 +96,6 @@ tls13_server_hello_retry_recv(struct tls13_ctx *ctx)
return 0;
}
-int
-tls13_client_hello_retry_recv(struct tls13_ctx *ctx)
-{
- return 0;
-}
-
-
int
tls13_client_end_of_early_data_send(struct tls13_ctx *ctx)
{
--
cgit v1.2.3-55-g6feb