Avoid a memory leak that results when the same tls_config is reused.

Reported by and fix from Nate Bessette <openbsd at nate dot sh> - thanks.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/lib/libtls/tls.c b/src/lib/libtls/tls.c
index f07c4c6deb..95fdb8bc4b 100644
--- a/src/lib/libtls/tls.c
+++ b/src/lib/libtls/tls.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls.c,v 1.71 2017/09/20 17:05:17 jsing Exp $ */
+/* $OpenBSD: tls.c,v 1.72 2018/02/08 08:04:12 jsing Exp $ */
 /*
  * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
  *
@@ -269,7 +269,9 @@ tls_cert_hash(X509 *cert, char **hash)
         char d[EVP_MAX_MD_SIZE], *dhex = NULL;
         int dlen, rv = -1;
 
+        free(*hash);
         *hash = NULL;
+
         if (X509_digest(cert, EVP_sha256(), d, &dlen) != 1)
                 goto err;
 
@@ -296,6 +298,7 @@ tls_keypair_pubkey_hash(struct tls_keypair *keypair, char **hash)
         char d[EVP_MAX_MD_SIZE], *dhex = NULL;
         int dlen, rv = -1;
 
+        free(*hash);
         *hash = NULL;
 
         if ((membio = BIO_new_mem_buf(keypair->cert_mem,