PORT_Assert(sigd);
NSS_CMSSignedData_GetDigestValue(NSSCMSSignedData *sigd, SECOidTag digestalgtag){    int n;    PORT_Assert(sigd);    if (!sigd) {        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);        return NULL;    }    if (sigd->digestAlgorithms == NULL)	return NULL;    n = NSS_CMSAlgArray_GetIndexByAlgTag(sigd->digestAlgorithms, digestalgtag);    return (n < 0) ? NULL : sigd->digests[n];}