lib/services/atomic-write-file.js
'use strict';
const baAsn1 = require('../asn1');
const baEnum = require('../enum');
module.exports.encode = (buffer, isStream, objectId, position, blocks) => {
baAsn1.encodeApplicationObjectId(buffer, objectId.type, objectId.instance);
if (isStream) {
baAsn1.encodeOpeningTag(buffer, 0);
baAsn1.encodeApplicationSigned(buffer, position);
baAsn1.encodeApplicationOctetString(buffer, blocks[0], 0, blocks[0].length);
baAsn1.encodeClosingTag(buffer, 0);
} else {
baAsn1.encodeOpeningTag(buffer, 1);
baAsn1.encodeApplicationSigned(buffer, position);
baAsn1.encodeApplicationUnsigned(buffer, blocks.length);
for (let i = 0; i < blocks.length; i++) {
baAsn1.encodeApplicationOctetString(buffer, blocks[i], 0, blocks[i].length);
}
baAsn1.encodeClosingTag(buffer, 1);
}
};
module.exports.decode = (buffer, offset, apduLen) => {
let len = 0;
let result;
let decodedValue;
let isStream;
let position;
const blocks = [];
let blockCount;
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber !== baEnum.ApplicationTags.OBJECTIDENTIFIER) return;
decodedValue = baAsn1.decodeObjectId(buffer, offset + len);
len += decodedValue.len;
const objectId = {type: decodedValue.objectType, instance: decodedValue.instance};
if (baAsn1.decodeIsOpeningTagNumber(buffer, offset + len, 0)) {
isStream = true;
len++;
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber !== baEnum.ApplicationTags.SIGNED_INTEGER) return;
decodedValue = baAsn1.decodeSigned(buffer, offset + len, result.value);
len += decodedValue.len;
position = decodedValue.value;
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber !== baEnum.ApplicationTags.OCTET_STRING) return;
decodedValue = baAsn1.decodeOctetString(buffer, offset + len, apduLen, 0, result.value);
len += decodedValue.len;
blocks.push(decodedValue.value);
if (!baAsn1.decodeIsClosingTagNumber(buffer, offset + len, 0)) return;
len++;
} else if (baAsn1.decodeIsOpeningTagNumber(buffer, offset + len, 1)) {
isStream = false;
len++;
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber !== baEnum.ApplicationTags.SIGNED_INTEGER) return;
decodedValue = baAsn1.decodeSigned(buffer, offset + len, result.value);
len += decodedValue.len;
position = decodedValue.value;
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber !== baEnum.ApplicationTags.UNSIGNED_INTEGER) return;
decodedValue = baAsn1.decodeUnsigned(buffer, offset + len, result.value);
len += decodedValue.len;
blockCount = decodedValue.value;
for (let i = 0; i < blockCount; i++) {
result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber !== baEnum.ApplicationTags.OCTET_STRING) return;
decodedValue = baAsn1.decodeOctetString(buffer, offset + len, apduLen, 0, result.value);
len += decodedValue.len;
blocks.push(decodedValue.value);
}
if (!baAsn1.decodeIsClosingTagNumber(buffer, offset + len, 1)) return;
len++;
} else {
return;
}
return {
len: len,
isStream: isStream,
objectId: objectId,
position: position,
blocks: blocks
};
};
module.exports.encodeAcknowledge = (buffer, isStream, position) => {
if (isStream) {
baAsn1.encodeContextSigned(buffer, 0, position);
} else {
baAsn1.encodeContextSigned(buffer, 1, position);
}
};
module.exports.decodeAcknowledge = (buffer, offset) => {
let len = 0;
let isStream = false;
let position = 0;
const result = baAsn1.decodeTagNumberAndValue(buffer, offset + len);
len += result.len;
if (result.tagNumber === 0) {
isStream = true;
} else if (result.tagNumber === 1) {
isStream = false;
} else {
return;
}
const decodedValue = baAsn1.decodeSigned(buffer, offset + len, result.value);
len += decodedValue.len;
position = decodedValue.value;
return {
len: len,
isStream: isStream,
position: position
};
};