From 2c0267fdc99f8a06cb205f0faecc2ff06f0de8bf Mon Sep 17 00:00:00 2001 From: Ben Kaduk Date: Tue, 4 Sep 2018 11:44:07 -0500 Subject: [PATCH] Restore historical SSL_get_servername() behavior Commit 1c4aa31d79821dee9be98e915159d52cc30d8403 modified the state machine to clean up stale ext.hostname values from SSL objects in the case when SNI was not negotiated for the current handshake. This is natural from the TLS perspective, since this information is an extension that the client offered but we ignored, and since we ignored it we do not need to keep it around for anything else. However, as documented in https://github.com/openssl/openssl/issues/7014 , there appear to be some deployed code that relies on retrieving such an ignored SNI value from the client, after the handshake has completed. Because the 1.1.1 release is on a stable branch and should preserve the published ABI, restore the historical behavior by retaining the ext.hostname value sent by the client, in the SSL structure, for subsequent retrieval. [extended tests] Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/7115) --- ssl/statem/extensions.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/ssl/statem/extensions.c b/ssl/statem/extensions.c index 307e6b9d6f..cd4f078cf3 100644 --- a/ssl/statem/extensions.c +++ b/ssl/statem/extensions.c @@ -938,11 +938,8 @@ static int final_server_name(SSL *s, unsigned int context, int sent) * was successful. */ if (s->server) { - if (!sent) { - /* Nothing from the client this handshake; cleanup stale value */ - OPENSSL_free(s->ext.hostname); - s->ext.hostname = NULL; - } else if (ret == SSL_TLSEXT_ERR_OK && (!s->hit || SSL_IS_TLS13(s))) { + /* TODO(OpenSSL1.2) revisit !sent case */ + if (sent && ret == SSL_TLSEXT_ERR_OK && (!s->hit || SSL_IS_TLS13(s))) { /* Only store the hostname in the session if we accepted it. */ OPENSSL_free(s->session->ext.hostname); s->session->ext.hostname = OPENSSL_strdup(s->ext.hostname); -- GitLab