+
+static void
+set_exim_authvar_from_prop(Gsasl_session * sctx, Gsasl_property prop)
+{
+uschar * propval = US gsasl_property_fast(sctx, prop);
+int i = expand_nmax, j = i + 1;
+propval = propval ? string_copy(propval) : US"";
+auth_vars[i] = expand_nstring[j] = propval;
+expand_nlength[j] = Ustrlen(propval);
+expand_nmax = j;
+}
+
+static void
+set_exim_authvars_from_a_az_r_props(Gsasl_session * sctx)
+{
+if (expand_nmax > 0 ) return;
+
+/* Asking for GSASL_AUTHZID calls back into us if we use
+gsasl_property_get(), thus the use of gsasl_property_fast().
+Do we really want to hardcode limits per mechanism? What happens when
+a new mechanism is added to the library. It *shouldn't* result in us
+needing to add more glue, since avoiding that is a large part of the
+point of SASL. */
+
+set_exim_authvar_from_prop(sctx, GSASL_AUTHID);
+set_exim_authvar_from_prop(sctx, GSASL_AUTHZID);
+set_exim_authvar_from_prop(sctx, GSASL_REALM);
+}
+
+