+/*
+ * SSL_export_keying_material_early exports a value derived from the
+ * early exporter master secret, as specified in
+ * https://tools.ietf.org/html/draft-ietf-tls-tls13-23. It writes
+ * |olen| bytes to |out| given a label and optional context. It
+ * returns 1 on success and 0 otherwise.
+ */
+__owur int SSL_export_keying_material_early(SSL *s, unsigned char *out,
+ size_t olen, const char *label,
+ size_t llen,
+ const unsigned char *context,
+ size_t contextlen);
+