diff --git a/ssl/ssl_lib.cc b/ssl/ssl_lib.cc
index 262f9b2..9c551c2 100644
--- a/ssl/ssl_lib.cc
+++ b/ssl/ssl_lib.cc
@@ -187,6 +187,17 @@
 static CRYPTO_EX_DATA_CLASS g_ex_data_class_ssl_ctx =
     CRYPTO_EX_DATA_CLASS_INIT_WITH_APP_DATA;
 
+bool CBBFinishArray(CBB *cbb, Array<uint8_t> *out) {
+  uint8_t *ptr;
+  size_t len;
+  if (!CBB_finish(cbb, &ptr, &len)) {
+    OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
+    return false;
+  }
+  out->Reset(ptr, len);
+  return true;
+}
+
 void ssl_reset_error_state(SSL *ssl) {
   // Functions which use |SSL_get_error| must reset I/O and error state on
   // entry.