Add accessors to config DN hints for cert request

mbedtls_ssl_conf_dn_hints()
mbedtls_ssl_set_hs_dn_hints()

Signed-off-by: Glenn Strauss <gstrauss@gluelogic.com>
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index 21e5cda..0952872 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -2489,6 +2489,16 @@
          *       `mbedtls_ssl_conf_ca_cb()`, then the
          *       CertificateRequest is currently left empty. */
 
+#if defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED)
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+        if( ssl->handshake->dn_hints != NULL )
+            crt = ssl->handshake->dn_hints;
+        else
+#endif
+        if( ssl->conf->dn_hints != NULL )
+            crt = ssl->conf->dn_hints;
+        else
+#endif
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
         if( ssl->handshake->sni_ca_chain != NULL )
             crt = ssl->handshake->sni_ca_chain;