Add tls13_secret_{init,cleanup}()

These are two functions that will help streamlining various functions
in the TLSv1.3 code that do not need to know about the interna of this
struct.

input/ok jsing

2 files changed, 29 insertions, 2 deletions

diff --git a/src/lib/libssl/tls13_internal.h b/src/lib/libssl/tls13_internal.h
index ea5f9a1473..c339a8ef10 100644
--- a/src/lib/libssl/tls13_internal.h
+++ b/src/lib/libssl/tls13_internal.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_internal.h,v 1.87 2020/11/16 18:55:15 jsing Exp $ */
+/* $OpenBSD: tls13_internal.h,v 1.88 2021/01/05 17:40:11 tb Exp $ */
 /*
  * Copyright (c) 2018 Bob Beck <beck@openbsd.org>
  * Copyright (c) 2018 Theo Buehler <tb@openbsd.org>
@@ -141,6 +141,8 @@ struct tls13_secrets {
         struct tls13_secret resumption_master;
 };
 
+int tls13_secret_init(struct tls13_secret *secret, size_t len);
+void tls13_secret_cleanup(struct tls13_secret *secret);
 struct tls13_secrets *tls13_secrets_create(const EVP_MD *digest,
     int resumption);
 void tls13_secrets_destroy(struct tls13_secrets *secrets);
diff --git a/src/lib/libssl/tls13_key_schedule.c b/src/lib/libssl/tls13_key_schedule.c
index 35180cfe5c..bf8699dc31 100644
--- a/src/lib/libssl/tls13_key_schedule.c
+++ b/src/lib/libssl/tls13_key_schedule.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_key_schedule.c,v 1.9 2020/11/16 18:55:15 jsing Exp $ */
+/* $OpenBSD: tls13_key_schedule.c,v 1.10 2021/01/05 17:40:11 tb Exp $ */
 /* Copyright (c) 2018, Bob Beck <beck@openbsd.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
@@ -22,6 +22,31 @@
 #include "bytestring.h"
 #include "tls13_internal.h"
 
+int
+tls13_secret_init(struct tls13_secret *secret, size_t len)
+{
+        uint8_t *data;
+
+        if (secret->data != NULL)
+                return 0;
+
+        if ((data = calloc(1, len)) == NULL)
+                return 0;
+
+        secret->data = data;
+        secret->len = len;
+
+        return 1;
+}
+
+void
+tls13_secret_cleanup(struct tls13_secret *secret)
+{
+        freezero(secret->data, secret->len);
+        secret->data = NULL;
+        secret->len = 0;
+}
+
 void
 tls13_secrets_destroy(struct tls13_secrets *secrets)
 {