From 5de683d2c6ae2f8c30b97326e72ff19f41228b74 Mon Sep 17 00:00:00 2001 From: Matt Caswell Date: Fri, 2 Mar 2018 15:02:11 +0000 Subject: [PATCH] Fix status_request and SCT extensions They are valid for use in a CertificateRequest message, but we did not allow it. If a server sent such a message using either of those two extensions then the handshake would abort. This corrects that error, but does not add support for actually processing the extensions. They are simply ignored, and a TODO is inserted to add support at a later time. This was found during interoperability testing with btls: https://gitlab.com/ilari_l/btls Prompted by these errors I reviewed the complete list of extensions and compared them with the latest table in draft-24 to confirm there were no other errors of a similar type. I did not find any. Reviewed-by: Rich Salz Reviewed-by: Ben Kaduk (Merged from https://github.com/openssl/openssl/pull/5490) --- ssl/statem/extensions.c | 4 ++-- ssl/statem/extensions_clnt.c | 12 ++++++++++++ 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/ssl/statem/extensions.c b/ssl/statem/extensions.c index 722943fa69..6e3f8d1672 100644 --- a/ssl/statem/extensions.c +++ b/ssl/statem/extensions.c @@ -211,7 +211,7 @@ static const EXTENSION_DEFINITION ext_defs[] = { { TLSEXT_TYPE_status_request, SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO - | SSL_EXT_TLS1_3_CERTIFICATE, + | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, init_status_request, tls_parse_ctos_status_request, tls_parse_stoc_status_request, tls_construct_stoc_status_request, tls_construct_ctos_status_request, NULL @@ -263,7 +263,7 @@ static const EXTENSION_DEFINITION ext_defs[] = { { TLSEXT_TYPE_signed_certificate_timestamp, SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO - | SSL_EXT_TLS1_3_CERTIFICATE, + | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, NULL, /* * No server side support for this, but can be provided by a custom diff --git a/ssl/statem/extensions_clnt.c b/ssl/statem/extensions_clnt.c index 6bc3d0da8e..d569f3b84e 100644 --- a/ssl/statem/extensions_clnt.c +++ b/ssl/statem/extensions_clnt.c @@ -1397,6 +1397,12 @@ int tls_parse_stoc_session_ticket(SSL *s, PACKET *pkt, unsigned int context, int tls_parse_stoc_status_request(SSL *s, PACKET *pkt, unsigned int context, X509 *x, size_t chainidx) { + if (context == SSL_EXT_TLS1_3_CERTIFICATE_REQUEST) { + /* We ignore this if the server sends a CertificateRequest */ + /* TODO(TLS1.3): Add support for this */ + return 1; + } + /* * MUST only be sent if we've requested a status * request message. In TLS <= 1.2 it must also be empty. @@ -1435,6 +1441,12 @@ int tls_parse_stoc_status_request(SSL *s, PACKET *pkt, unsigned int context, int tls_parse_stoc_sct(SSL *s, PACKET *pkt, unsigned int context, X509 *x, size_t chainidx) { + if (context == SSL_EXT_TLS1_3_CERTIFICATE_REQUEST) { + /* We ignore this if the server sends it in a CertificateRequest */ + /* TODO(TLS1.3): Add support for this */ + return 1; + } + /* * Only take it if we asked for it - i.e if there is no CT validation * callback set, then a custom extension MAY be processing it, so we -- 2.25.1