const char *hex = "0123456789abcdef";

    if (resultObj == NULL) {
	return NULL;
    }

    for (int i = 0; i < ilen; i++) {
        *dptr++ = hex[(*iptr>>4)&0xF];
        *dptr++ = hex[(*iptr++)&0xF];
    }
    return resultObj;
}

/*
 *-----------------------------------------------------------------------------
 *

    LAPPEND_BOOL(interp, resultObj, "extInvalid", xflags & EXFLAG_INVALID);
    LAPPEND_BOOL(interp, resultObj, "isCACert", X509_check_ca(cert));

    /* The Unique Ids are used to handle the possibility of reuse of subject
	and/or issuer names over time. RFC 5280 section 4.1.2.8 */
    {
	const ASN1_BIT_STRING *iuid, *suid;
        X509_get0_uids(cert, &iuid, &suid);

	Tcl_ListObjAppendElement(interp, resultObj, Tcl_NewStringObj("issuerUniqueId", -1));
	if (iuid != NULL) {
	    Tcl_ListObjAppendElement(interp, resultObj, Tcl_NewByteArrayObj((const unsigned char *)iuid->data, (Tcl_Size) iuid->length));
	} else {
	    Tcl_ListObjAppendElement(interp, resultObj, Tcl_NewStringObj("", -1));
	}

    /* Subject Information Access - RFC 5280 section 4.2.2.2, NID_sinfo_access */

    /* Certificate Alias. If uses a PKCS#12 structure, alias will reflect the
	friendlyName attribute (RFC 2985). */
    {
	int ilen = 0;
        unsigned char *string = X509_alias_get0(cert, &ilen);
	LAPPEND_STR(interp, resultObj, "alias", (char *) string, (Tcl_Size) ilen);
        string = X509_keyid_get0(cert, &ilen);
	LAPPEND_STR(interp, resultObj, "keyId", (char *) string, (Tcl_Size) ilen);
    }

    /* Certificate and dump all data */
    if (all) {
	Tcl_Obj *allObj = Tcl_NewByteArrayObj(NULL, 0);
	Tcl_Obj *certObj = Tcl_NewByteArrayObj(NULL, 0);