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shrine-medco/shrine-webclient/src/main/tools/gopherjsCrypto/tests/scripts/workersController.js
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workersController.js
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i2b2 = {};
i2b2.MedCo = {};
i2b2.MedCo.ctrlr = {};
// a structure to handle the workers (background threads)
i2b2.MedCo.ctrlr.background = {
// from outside you should just call the following
// 1. initWorkers() and initEncrypt() (in whatever order)
// 2. toBeEncrypted() x N (call this functions whenever you have something to encrypt)
// 3. done() (wait/check if encryption has finished)
// here is stored the list of workers of with the workload can be spread
workers: [],
// This is a map from plaintexts to the corresponding ciphertext to avoid encrypting again.
// It is updated every time a worker encrypts new integer.
encryptionCache: {},
// A list of plaintexts that have to be encrypted (notice that some of these my have the corresponding ciphertext
// in the encryptionCache). When a plaintext is encrypted it is saved in encryptionCache and removed from toEncrypt
toEncrypt: [],
// store the number of remaining plaintext to encrypt ("toEncrypt.length" may be different from "remaining" since
// when a plaintext is sent to a worker it is removed from toEncrypt but "remaining" is not decreased yet)
remaining: 0,
// K and S are the parameters that will be used to encrypt
K: null,
S: null,
// aggregate public key of the cothority (used to decrypt)
AggregateKey: "GKrufk6bsuMwegxcPqr7B1aFWKit1szJlugZ01HkSPA=",
// init initializes the workers (to create them one time and then just send them the strings to
// encrypt/decrypt). Initialise a worker may take some seconds because each one of them ahas to import
// the crypto javascript
initWorkers: function(num_workers){
var context = i2b2.MedCo.ctrlr.background;
// first kill the existing workers, if any
for (var i=0; i < context.workers.length; i++) {
context.workers[i].terminate();
}
context.workers = [];
// todo be careful the importPath to points to the correct location of the file
var importPath = document.location["href"];
// you have to tell the workers where the crypto library is so that they can import it
importPath = importPath.substr(0, importPath.lastIndexOf('/')) + "/scripts/cryptolib.js";
for (var i=0; i < num_workers; i++){
// start a new worker
var w = new Worker(URL.createObjectURL(new Blob(["("+worker_code.toString()+")()"], {type: 'text/javascript'})));
// register to each worker an encrypt function that will look for something to encrypt and send it
// to the worker
w.encrypt = function (){
// look for something to encrypt
for (var i=0; i < context.toEncrypt.length; i++){
if (context.toEncrypt[i] in context.encryptionCache){ // it has been encrypted in the past
context.toEncrypt.shift();
context.remaining -= 1;
}
else{
w.postMessage({"enc": {"plain": context.toEncrypt.shift(), "K": context.K, "S": context.S}})
break
}
}
};
// register event for the result
w.onmessage = function(e) {
var task = Object.keys(e.data)[0];
switch (task) {
case "enc":
var plain = e.data[task]["plain"];
var cipher = e.data[task]["cipher"];
context.encryptionCache[plain] = cipher;
context.remaining -= 1;
document.getElementById("encrypted").innerHTML += JSON.stringify(e.data[task]) + "<br>"; // todo delete
// start another encryption
w.encrypt();
break;
case "dec":
// todo
break;
default:
alert("Message received from the worker not recognized:" + JSON.stringify(e.data))
}
};
w.postMessage({"init": {"import": importPath}});
context.workers.push(w)
}
},
initEncrypt: function(){
var context = i2b2.MedCo.ctrlr.background;
// init the ephemeral key of the light encryption
[context.K, context.S] = LightEncryptStr_init(context.AggregateKey);
context.encryptionCache = {}; // old ciphertexts are not valid anymore
},
// receives a list of plaintexts to be encrypted and append it to the toEncrypt list
toBeEncrypted: function(toEncrypt){
var context = i2b2.MedCo.ctrlr.background;
// other plaintext to be encrypted are appended to the list
context.toEncrypt = context.toEncrypt.concat(toEncrypt);
context.remaining += toEncrypt.length;
// sends to each worker something to encrypt
for(var i=0; i < context.workers.length; i++){
context.workers[i].encrypt(); // function registered to the worker (see init)
}
},
// checks if there are other plaintexts to be encrypted
done: function() {
return i2b2.MedCo.ctrlr.background.remaining == 0;
}
};
// all worker code here (this function is just used to create workers in the i2b2.MedCo.ctrlr.background.init)
function worker_code() {
// a worker responds to 3 different messages, init, encrypt, decrypt
onmessage = function(e) {
// e.data is in one of the following forms -> response:
// - {"init": {"import": "http://.../cryptolib.js"}} -> no response
// - {"enc": {"plain": "123", "K": "...", "S": "..."}} -> {"enc": {"plain": "<plaintext>", "cipher": "<ciphertext>"}}
// - todo {"dec": { ... }} -> {"dec": {"<ciphertext>": "<plaintext>"}}
var task = Object.keys(e.data)[0];
switch (task){
case "init":
self.importScripts(e.data[task]["import"]); // e.g. self.importScripts("http://localhost:63342/i-b-webclient/tools/gopherjsCrypto/tests/scripts/useme.js");
console.log("worker says: imported cryptolib");
break;
case "enc":
var plain = e.data[task]["plain"];
var K = e.data[task]["K"];
var S = e.data[task]["S"];
var cipher = LightEncryptStr(plain, K, S);
console.log("worker says: plain: " + plain + "; cipher: ", cipher);
// {"enc": {"<plaintext>": "<ciphertext>"}}
var response = {};
response[task] = {};
response[task]["plain"] = plain;
response[task]["cipher"] = cipher;
postMessage(response);
break;
case "dec":
// todo
break;
default:
alert("worker says: message not recognized: " + JSON.stringify(e.data))
}
};
}
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