r2-shared-js
Version:
Readium 2 'shared' for NodeJS (TypeScript)
75 lines • 3.59 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.TransformerObfIDPF = void 0;
var tslib_1 = require("tslib");
var crypto = require("crypto");
var BufferUtils_1 = require("r2-utils-js/dist/es5/src/_utils/stream/BufferUtils");
var TransformerObfIDPF = (function () {
function TransformerObfIDPF() {
}
TransformerObfIDPF.prototype.supports = function (_publication, link) {
return link.Properties && link.Properties.Encrypted &&
link.Properties.Encrypted.Algorithm === "http://www.idpf.org/2008/embedding";
};
TransformerObfIDPF.prototype.transformStream = function (publication, link, _url, stream, _isPartialByteRangeRequest, _partialByteBegin, _partialByteEnd, _sessionInfo) {
return tslib_1.__awaiter(this, void 0, void 0, function () {
var data, err_1, buff, err_2, sal;
var _this = this;
return tslib_1.__generator(this, function (_a) {
switch (_a.label) {
case 0:
_a.trys.push([0, 2, , 3]);
return [4, (0, BufferUtils_1.streamToBufferPromise)(stream.stream)];
case 1:
data = _a.sent();
return [3, 3];
case 2:
err_1 = _a.sent();
return [2, Promise.reject(err_1)];
case 3:
_a.trys.push([3, 5, , 6]);
return [4, this.transformBuffer(publication, link, data)];
case 4:
buff = _a.sent();
return [3, 6];
case 5:
err_2 = _a.sent();
return [2, Promise.reject(err_2)];
case 6:
sal = {
length: buff.length,
reset: function () { return tslib_1.__awaiter(_this, void 0, void 0, function () {
return tslib_1.__generator(this, function (_a) {
return [2, Promise.resolve(sal)];
});
}); },
stream: (0, BufferUtils_1.bufferToStream)(buff),
};
return [2, Promise.resolve(sal)];
}
});
});
};
TransformerObfIDPF.prototype.transformBuffer = function (publication, _link, data) {
return tslib_1.__awaiter(this, void 0, void 0, function () {
var pubID, checkSum, key, prefixLength, zipDataPrefix, i, zipDataRemainder;
return tslib_1.__generator(this, function (_a) {
pubID = publication.Metadata.Identifier;
pubID = pubID.replace(/\s/g, "");
checkSum = crypto.createHash("sha1");
checkSum.update(pubID);
key = checkSum.digest();
prefixLength = 1040;
zipDataPrefix = data.slice(0, prefixLength);
for (i = 0; i < prefixLength; i++) {
zipDataPrefix[i] = zipDataPrefix[i] ^ (key[i % key.length]);
}
zipDataRemainder = data.slice(prefixLength);
return [2, Promise.resolve(Buffer.concat([zipDataPrefix, zipDataRemainder]))];
});
});
};
return TransformerObfIDPF;
}());
exports.TransformerObfIDPF = TransformerObfIDPF;
//# sourceMappingURL=transformer-obf-idpf.js.map