From f5ed4f0bbe31617b6df897ac6a28af9b3c8fd18e Mon Sep 17 00:00:00 2001 From: Matt Caswell Date: Mon, 20 Sep 2021 14:15:18 +0100 Subject: New extensions can be sent in a certificate request Normally we expect a client to send new extensions in the ClientHello, which may be echoed back by the server in subsequent messages. However the server can also send a new extension in the certificate request message to be echoed back in a certificate message Fixes #16632 Reviewed-by: Paul Dale Reviewed-by: Tomas Mraz (Merged from https://github.com/openssl/openssl/pull/16634) (cherry picked from commit cbb862fbaaa1ec5a3e33836bc92a6dbea97ceba0) --- ssl/statem/extensions_cust.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'ssl') diff --git a/ssl/statem/extensions_cust.c b/ssl/statem/extensions_cust.c index a0ba18efa7..fa24344db7 100644 --- a/ssl/statem/extensions_cust.c +++ b/ssl/statem/extensions_cust.c @@ -146,11 +146,12 @@ int custom_ext_parse(SSL *s, unsigned int context, unsigned int ext_type, } /* - * Extensions received in the ClientHello are marked with the - * SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent - * extensions in the ServerHello/EncryptedExtensions message + * Extensions received in the ClientHello or CertificateRequest are marked + * with the SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent + * extensions in the response messages */ - if ((context & SSL_EXT_CLIENT_HELLO) != 0) + if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST)) + != 0) meth->ext_flags |= SSL_EXT_FLAG_RECEIVED; /* If no parse function set return success */ @@ -192,7 +193,7 @@ int custom_ext_add(SSL *s, int context, WPACKET *pkt, X509 *x, size_t chainidx, | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) { - /* Only send extensions present in ClientHello. */ + /* Only send extensions present in ClientHello/CertificateRequest */ if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED)) continue; } -- cgit v1.2.3