lib/services/read-property.js
'use strict';
const baAsn1 = require('../asn1');
const baEnum = require('../enum');
module.exports.encode = (buffer, objectType, objectInstance, propertyId, arrayIndex) => {
if (objectType <= baEnum.ASN1_MAX_OBJECT) {
baAsn1.encodeContextObjectId(buffer, 0, objectType, objectInstance);
}
if (propertyId <= baEnum.ASN1_MAX_PROPERTY_ID) {
baAsn1.encodeContextEnumerated(buffer, 1, propertyId);
}
if (arrayIndex !== baEnum.ASN1_ARRAY_ALL) {
baAsn1.encodeContextUnsigned(buffer, 2, arrayIndex || baEnum.ASN1_ARRAY_ALL);
}
};
module.exports.decode = (buffer, offset, apduLen) => {
let len = 0;
let result;
let decodedValue;
if (apduLen < 7) return;
if (!baAsn1.decodeIsContextTag(buffer, offset + len, 0)) return;
len++;
decodedValue = baAsn1.decodeObjectId(buffer, offset + len);
len += decodedValue.len;
const objectId = {type: decodedValue.objectType, instance: decodedValue.instance};
const property = {};
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber !== 1) return;
decodedValue = baAsn1.decodeEnumerated(buffer, offset + len, result.value);
len += decodedValue.len;
property.id = decodedValue.value;
property.index = baEnum.ASN1_ARRAY_ALL;
if (len < apduLen) {
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if ((result.tagNumber === 2) && (len < apduLen)) {
decodedValue = baAsn1.decodeUnsigned(buffer, offset + len, result.value);
len += decodedValue.len;
property.index = decodedValue.value;
} else {
return;
}
}
if (len < apduLen) return;
return {
len: len,
objectId: objectId,
property: property
};
};
module.exports.encodeAcknowledge = (buffer, objectId, propertyId, arrayIndex, values) => {
baAsn1.encodeContextObjectId(buffer, 0, objectId.type, objectId.instance);
baAsn1.encodeContextEnumerated(buffer, 1, propertyId);
if (arrayIndex !== baEnum.ASN1_ARRAY_ALL) {
baAsn1.encodeContextUnsigned(buffer, 2, arrayIndex);
}
baAsn1.encodeOpeningTag(buffer, 3);
values.forEach((value) => {
baAsn1.bacappEncodeApplicationData(buffer, value);
});
baAsn1.encodeClosingTag(buffer, 3);
};
module.exports.decodeAcknowledge = (buffer, offset, apduLen) => {
let result;
let decodedValue;
const objectId = {};
const property = {};
if (!baAsn1.decodeIsContextTag(buffer, offset, 0)) return;
let len = 1;
result = baAsn1.decodeObjectId(buffer, offset + len);
len += result.len;
objectId.type = result.objectType;
objectId.instance = result.instance;
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber !== 1) return;
result = baAsn1.decodeEnumerated(buffer, offset + len, result.value);
len += result.len;
property.id = result.value;
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
if (result.tagNumber === 2) {
len += result.len;
decodedValue = baAsn1.decodeUnsigned(buffer, offset + len, result.value);
len += decodedValue.len;
property.index = decodedValue.value;
} else {
property.index = baEnum.ASN1_ARRAY_ALL;
}
const values = [];
if (!baAsn1.decodeIsOpeningTagNumber(buffer, offset + len, 3)) return;
len++;
while ((apduLen - len) > 1) {
result = baAsn1.bacappDecodeApplicationData(buffer, offset + len, apduLen + offset, objectId.type, property.id);
if (!result) return;
len += result.len;
delete result.len;
values.push(result);
}
if (!baAsn1.decodeIsClosingTagNumber(buffer, offset + len, 3)) return;
len++;
return {
len: len,
objectId: objectId,
property: property,
values: values
};
};