diff options
author | Minteck <contact@minteck.org> | 2023-01-10 14:54:04 +0100 |
---|---|---|
committer | Minteck <contact@minteck.org> | 2023-01-10 14:54:04 +0100 |
commit | 99c1d9af689e5325f3cf535c4007b3aeb8325229 (patch) | |
tree | e663b3c2ebdbd67c818ac0c5147f0ce1d2463cda /school/node_modules/node-forge/js/prime.js | |
parent | 9871b03912fc28ad38b4037ebf26a78aa937baba (diff) | |
download | pluralconnect-99c1d9af689e5325f3cf535c4007b3aeb8325229.tar.gz pluralconnect-99c1d9af689e5325f3cf535c4007b3aeb8325229.tar.bz2 pluralconnect-99c1d9af689e5325f3cf535c4007b3aeb8325229.zip |
Update - This is an automated commit
Diffstat (limited to 'school/node_modules/node-forge/js/prime.js')
-rw-r--r-- | school/node_modules/node-forge/js/prime.js | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/school/node_modules/node-forge/js/prime.js b/school/node_modules/node-forge/js/prime.js new file mode 100644 index 0000000..2857c36 --- /dev/null +++ b/school/node_modules/node-forge/js/prime.js @@ -0,0 +1,337 @@ +/** + * Prime number generation API. + * + * @author Dave Longley + * + * Copyright (c) 2014 Digital Bazaar, Inc. + */ +(function() { +/* ########## Begin module implementation ########## */ +function initModule(forge) { + +// forge.prime already defined +if(forge.prime) { + return; +} + +/* PRIME API */ +var prime = forge.prime = forge.prime || {}; + +var BigInteger = forge.jsbn.BigInteger; + +// primes are 30k+i for i = 1, 7, 11, 13, 17, 19, 23, 29 +var GCD_30_DELTA = [6, 4, 2, 4, 2, 4, 6, 2]; +var THIRTY = new BigInteger(null); +THIRTY.fromInt(30); +var op_or = function(x, y) {return x|y;}; + +/** + * Generates a random probable prime with the given number of bits. + * + * Alternative algorithms can be specified by name as a string or as an + * object with custom options like so: + * + * { + * name: 'PRIMEINC', + * options: { + * maxBlockTime: <the maximum amount of time to block the main + * thread before allowing I/O other JS to run>, + * millerRabinTests: <the number of miller-rabin tests to run>, + * workerScript: <the worker script URL>, + * workers: <the number of web workers (if supported) to use, + * -1 to use estimated cores minus one>. + * workLoad: the size of the work load, ie: number of possible prime + * numbers for each web worker to check per work assignment, + * (default: 100). + * } + * } + * + * @param bits the number of bits for the prime number. + * @param options the options to use. + * [algorithm] the algorithm to use (default: 'PRIMEINC'). + * [prng] a custom crypto-secure pseudo-random number generator to use, + * that must define "getBytesSync". + * + * @return callback(err, num) called once the operation completes. + */ +prime.generateProbablePrime = function(bits, options, callback) { + if(typeof options === 'function') { + callback = options; + options = {}; + } + options = options || {}; + + // default to PRIMEINC algorithm + var algorithm = options.algorithm || 'PRIMEINC'; + if(typeof algorithm === 'string') { + algorithm = {name: algorithm}; + } + algorithm.options = algorithm.options || {}; + + // create prng with api that matches BigInteger secure random + var prng = options.prng || forge.random; + var rng = { + // x is an array to fill with bytes + nextBytes: function(x) { + var b = prng.getBytesSync(x.length); + for(var i = 0; i < x.length; ++i) { + x[i] = b.charCodeAt(i); + } + } + }; + + if(algorithm.name === 'PRIMEINC') { + return primeincFindPrime(bits, rng, algorithm.options, callback); + } + + throw new Error('Invalid prime generation algorithm: ' + algorithm.name); +}; + +function primeincFindPrime(bits, rng, options, callback) { + if('workers' in options) { + return primeincFindPrimeWithWorkers(bits, rng, options, callback); + } + return primeincFindPrimeWithoutWorkers(bits, rng, options, callback); +} + +function primeincFindPrimeWithoutWorkers(bits, rng, options, callback) { + // initialize random number + var num = generateRandom(bits, rng); + + /* Note: All primes are of the form 30k+i for i < 30 and gcd(30, i)=1. The + number we are given is always aligned at 30k + 1. Each time the number is + determined not to be prime we add to get to the next 'i', eg: if the number + was at 30k + 1 we add 6. */ + var deltaIdx = 0; + + // get required number of MR tests + var mrTests = getMillerRabinTests(num.bitLength()); + if('millerRabinTests' in options) { + mrTests = options.millerRabinTests; + } + + // find prime nearest to 'num' for maxBlockTime ms + // 10 ms gives 5ms of leeway for other calculations before dropping + // below 60fps (1000/60 == 16.67), but in reality, the number will + // likely be higher due to an 'atomic' big int modPow + var maxBlockTime = 10; + if('maxBlockTime' in options) { + maxBlockTime = options.maxBlockTime; + } + var start = +new Date(); + do { + // overflow, regenerate random number + if(num.bitLength() > bits) { + num = generateRandom(bits, rng); + } + // do primality test + if(num.isProbablePrime(mrTests)) { + return callback(null, num); + } + // get next potential prime + num.dAddOffset(GCD_30_DELTA[deltaIdx++ % 8], 0); + } while(maxBlockTime < 0 || (+new Date() - start < maxBlockTime)); + + // keep trying (setImmediate would be better here) + forge.util.setImmediate(function() { + primeincFindPrimeWithoutWorkers(bits, rng, options, callback); + }); +} + +function primeincFindPrimeWithWorkers(bits, rng, options, callback) { + // web workers unavailable + if(typeof Worker === 'undefined') { + return primeincFindPrimeWithoutWorkers(bits, rng, options, callback); + } + + // initialize random number + var num = generateRandom(bits, rng); + + // use web workers to generate keys + var numWorkers = options.workers; + var workLoad = options.workLoad || 100; + var range = workLoad * 30 / 8; + var workerScript = options.workerScript || 'forge/prime.worker.js'; + if(numWorkers === -1) { + return forge.util.estimateCores(function(err, cores) { + if(err) { + // default to 2 + cores = 2; + } + numWorkers = cores - 1; + generate(); + }); + } + generate(); + + function generate() { + // require at least 1 worker + numWorkers = Math.max(1, numWorkers); + + // TODO: consider optimizing by starting workers outside getPrime() ... + // note that in order to clean up they will have to be made internally + // asynchronous which may actually be slower + + // start workers immediately + var workers = []; + for(var i = 0; i < numWorkers; ++i) { + // FIXME: fix path or use blob URLs + workers[i] = new Worker(workerScript); + } + var running = numWorkers; + + // listen for requests from workers and assign ranges to find prime + for(var i = 0; i < numWorkers; ++i) { + workers[i].addEventListener('message', workerMessage); + } + + /* Note: The distribution of random numbers is unknown. Therefore, each + web worker is continuously allocated a range of numbers to check for a + random number until one is found. + + Every 30 numbers will be checked just 8 times, because prime numbers + have the form: + + 30k+i, for i < 30 and gcd(30, i)=1 (there are 8 values of i for this) + + Therefore, if we want a web worker to run N checks before asking for + a new range of numbers, each range must contain N*30/8 numbers. + + For 100 checks (workLoad), this is a range of 375. */ + + var found = false; + function workerMessage(e) { + // ignore message, prime already found + if(found) { + return; + } + + --running; + var data = e.data; + if(data.found) { + // terminate all workers + for(var i = 0; i < workers.length; ++i) { + workers[i].terminate(); + } + found = true; + return callback(null, new BigInteger(data.prime, 16)); + } + + // overflow, regenerate random number + if(num.bitLength() > bits) { + num = generateRandom(bits, rng); + } + + // assign new range to check + var hex = num.toString(16); + + // start prime search + e.target.postMessage({ + hex: hex, + workLoad: workLoad + }); + + num.dAddOffset(range, 0); + } + } +} + +/** + * Generates a random number using the given number of bits and RNG. + * + * @param bits the number of bits for the number. + * @param rng the random number generator to use. + * + * @return the random number. + */ +function generateRandom(bits, rng) { + var num = new BigInteger(bits, rng); + // force MSB set + var bits1 = bits - 1; + if(!num.testBit(bits1)) { + num.bitwiseTo(BigInteger.ONE.shiftLeft(bits1), op_or, num); + } + // align number on 30k+1 boundary + num.dAddOffset(31 - num.mod(THIRTY).byteValue(), 0); + return num; +} + +/** + * Returns the required number of Miller-Rabin tests to generate a + * prime with an error probability of (1/2)^80. + * + * See Handbook of Applied Cryptography Chapter 4, Table 4.4. + * + * @param bits the bit size. + * + * @return the required number of iterations. + */ +function getMillerRabinTests(bits) { + if(bits <= 100) return 27; + if(bits <= 150) return 18; + if(bits <= 200) return 15; + if(bits <= 250) return 12; + if(bits <= 300) return 9; + if(bits <= 350) return 8; + if(bits <= 400) return 7; + if(bits <= 500) return 6; + if(bits <= 600) return 5; + if(bits <= 800) return 4; + if(bits <= 1250) return 3; + return 2; +} + +} // end module implementation + +/* ########## Begin module wrapper ########## */ +var name = 'prime'; +if(typeof define !== 'function') { + // NodeJS -> AMD + if(typeof module === 'object' && module.exports) { + var nodeJS = true; + define = function(ids, factory) { + factory(require, module); + }; + } else { + // <script> + if(typeof forge === 'undefined') { + forge = {}; + } + return initModule(forge); + } +} +// AMD +var deps; +var defineFunc = function(require, module) { + module.exports = function(forge) { + var mods = deps.map(function(dep) { + return require(dep); + }).concat(initModule); + // handle circular dependencies + forge = forge || {}; + forge.defined = forge.defined || {}; + if(forge.defined[name]) { + return forge[name]; + } + forge.defined[name] = true; + for(var i = 0; i < mods.length; ++i) { + mods[i](forge); + } + return forge[name]; + }; +}; +var tmpDefine = define; +define = function(ids, factory) { + deps = (typeof ids === 'string') ? factory.slice(2) : ids.slice(2); + if(nodeJS) { + delete define; + return tmpDefine.apply(null, Array.prototype.slice.call(arguments, 0)); + } + define = tmpDefine; + return define.apply(null, Array.prototype.slice.call(arguments, 0)); +}; +define(['require', 'module', './util', './jsbn', './random'], function() { + defineFunc.apply(null, Array.prototype.slice.call(arguments, 0)); +}); + +})(); |