KU_NON_REPUDIATION
if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION))
((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
!(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))