nist_cp_bn_0
nist_cp_bn_0(t_d, a_d + (BN_NIST_521_TOP - 1),
nist_cp_bn_0(buf.bn, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP,
nist_cp_bn_0(c_d, a_d + (BN_NIST_224_TOP - 1),
nist_cp_bn_0(buf.bn, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP,
nist_cp_bn_0(buf.bn, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP,
nist_cp_bn_0(buf.bn, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP,