bigint-crypto-utils/dist/bigint-crypto-utils-latest....

792 lines
20 KiB
JavaScript
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

const _ZERO = BigInt(0);
const _ONE = BigInt(1);
const _TWO = BigInt(2);
/**
* Absolute value. abs(a)==a if a>=0. abs(a)==-a if a<0
*
* @param {number|bigint} a
*
* @returns {bigint} the absolute value of a
*/
function abs(a) {
a = BigInt(a);
return (a >= _ZERO) ? a : -a;
}
/**
* Returns the bitlength of a number
*
* @param {number|bigint} a
* @returns {number} - the bit length
*/
function bitLength(a) {
a = BigInt(a);
if (a === _ONE)
return 1;
let bits = 1;
do {
bits++;
} while ((a >>= _ONE) > _ONE);
return bits;
}
/**
* @typedef {Object} egcdReturn A triple (g, x, y), such that ax + by = g = gcd(a, b).
* @property {bigint} g
* @property {bigint} x
* @property {bigint} y
*/
/**
* An iterative implementation of the extended euclidean algorithm or extended greatest common divisor algorithm.
* Take positive integers a, b as input, and return a triple (g, x, y), such that ax + by = g = gcd(a, b).
*
* @param {number|bigint} a
* @param {number|bigint} b
*
* @returns {egcdReturn} A triple (g, x, y), such that ax + by = g = gcd(a, b).
*/
function eGcd(a, b) {
a = BigInt(a);
b = BigInt(b);
if (a <= _ZERO | b <= _ZERO)
return NaN; // a and b MUST be positive
let x = _ZERO;
let y = _ONE;
let u = _ONE;
let v = _ZERO;
while (a !== _ZERO) {
let q = b / a;
let r = b % a;
let m = x - (u * q);
let n = y - (v * q);
b = a;
a = r;
x = u;
y = v;
u = m;
v = n;
}
return {
b: b,
x: x,
y: y
};
}
/**
* Greatest-common divisor of two integers based on the iterative binary algorithm.
*
* @param {number|bigint} a
* @param {number|bigint} b
*
* @returns {bigint} The greatest common divisor of a and b
*/
function gcd(a, b) {
a = abs(a);
b = abs(b);
if (a === _ZERO)
return b;
else if (b === _ZERO)
return a;
let shift = _ZERO;
while (!((a | b) & _ONE)) {
a >>= _ONE;
b >>= _ONE;
shift++;
}
while (!(a & _ONE)) a >>= _ONE;
do {
while (!(b & _ONE)) b >>= _ONE;
if (a > b) {
let x = a;
a = b;
b = x;
}
b -= a;
} while (b);
// rescale
return a << shift;
}
/**
* The test first tries if any of the first 250 small primes are a factor of the input number and then passes several
* iterations of Miller-Rabin Probabilistic Primality Test (FIPS 186-4 C.3.1)
*
* @param {number|bigint} w An integer to be tested for primality
* @param {number} [iterations = 16] The number of iterations for the primality test. The value shall be consistent with Table C.1, C.2 or C.3
*
* @return {Promise} A promise that resolves to a boolean that is either true (a probably prime number) or false (definitely composite)
*/
async function isProbablyPrime(w, iterations = 16) {
if (typeof w === 'number') {
w = BigInt(w);
}
{ // browser
return new Promise((resolve, reject) => {
const worker = new Worker(_isProbablyPrimeWorkerUrl());
worker.onmessage = (event) => {
worker.terminate();
resolve(event.data.isPrime);
};
worker.onmessageerror = (event) => {
reject(event);
};
worker.postMessage({
'rnd': w,
'iterations': iterations,
'id': 0
});
});
}
}
/**
* The least common multiple computed as abs(a*b)/gcd(a,b)
* @param {number|bigint} a
* @param {number|bigint} b
*
* @returns {bigint} The least common multiple of a and b
*/
function lcm(a, b) {
a = BigInt(a);
b = BigInt(b);
if (a === _ZERO && b === _ZERO)
return _ZERO;
return abs(a * b) / gcd(a, b);
}
/**
* Maximum. max(a,b)==a if a>=b. max(a,b)==b if a<=b
*
* @param {number|bigint} a
* @param {number|bigint} b
*
* @returns {bigint} maximum of numbers a and b
*/
function max(a, b) {
a = BigInt(a);
b = BigInt(b);
return (a >= b) ? a : b;
}
/**
* Minimum. min(a,b)==b if a>=b. min(a,b)==a if a<=b
*
* @param {number|bigint} a
* @param {number|bigint} b
*
* @returns {bigint} minimum of numbers a and b
*/
function min(a, b) {
a = BigInt(a);
b = BigInt(b);
return (a >= b) ? b : a;
}
/**
* Modular inverse.
*
* @param {number|bigint} a The number to find an inverse for
* @param {number|bigint} n The modulo
*
* @returns {bigint} the inverse modulo n or NaN if it does not exist
*/
function modInv(a, n) {
if (a == _ZERO | n <= _ZERO)
return NaN;
let egcd = eGcd(toZn(a, n), n);
if (egcd.b !== _ONE) {
return NaN; // modular inverse does not exist
} else {
return toZn(egcd.x, n);
}
}
/**
* Modular exponentiation b**e mod n. Currently using the right-to-left binary method
*
* @param {number|bigint} b base
* @param {number|bigint} e exponent
* @param {number|bigint} n modulo
*
* @returns {bigint} b**e mod n
*/
function modPow(b, e, n) {
n = BigInt(n);
if (n === _ZERO)
return NaN;
else if (n === _ONE)
return _ZERO;
b = toZn(b, n);
e = BigInt(e);
if (e < _ZERO) {
return modInv(modPow(b, abs(e), n), n);
}
let r = _ONE;
while (e > 0) {
if ((e % _TWO) === _ONE) {
r = (r * b) % n;
}
e = e / _TWO;
b = b ** _TWO % n;
}
return r;
}
/**
* A probably-prime (Miller-Rabin), cryptographically-secure, random-number generator.
* The browser version uses web workers to parallelise prime look up. Therefore, it does not lock the UI
* main process, and it can be much faster (if several cores or cpu are available).
* The node version can also use worker_threads if they are available (enabled by default with Node 11 and
* and can be enabled at runtime executing node --experimental-worker with node >=10.5.0).
*
* @param {number} bitLength The required bit length for the generated prime
* @param {number} [iterations = 16] The number of iterations for the Miller-Rabin Probabilistic Primality Test
*
* @returns {Promise} A promise that resolves to a bigint probable prime of bitLength bits.
*/
function prime(bitLength, iterations = 16) {
if (bitLength < 1)
throw new RangeError(`bitLength MUST be > 0 and it is ${bitLength}`);
return new Promise((resolve) => {
let workerList = [];
const _onmessage = (msg, newWorker) => {
if (msg.isPrime) {
// if a prime number has been found, stop all the workers, and return it
for (let j = 0; j < workerList.length; j++) {
workerList[j].terminate();
}
while (workerList.length) {
workerList.pop();
}
resolve(msg.value);
} else { // if a composite is found, make the worker test another random number
let buf = randBits(bitLength, true);
let rnd = fromBuffer(buf);
try {
newWorker.postMessage({
'rnd': rnd,
'iterations': iterations,
'id': msg.id
});
} catch (error) {
// The worker has already terminated. There is nothing to handle here
}
}
};
{ //browser
let workerURL = _isProbablyPrimeWorkerUrl();
for (let i = 0; i < self.navigator.hardwareConcurrency; i++) {
let newWorker = new Worker(workerURL);
newWorker.onmessage = (event) => _onmessage(event.data, newWorker);
workerList.push(newWorker);
}
}
for (let i = 0; i < workerList.length; i++) {
let buf = randBits(bitLength, true);
let rnd = fromBuffer(buf);
workerList[i].postMessage({
'rnd': rnd,
'iterations': iterations,
'id': i
});
}
});
}
/**
* A probably-prime (Miller-Rabin), cryptographically-secure, random-number generator.
* The sync version is NOT RECOMMENDED since it won't use workers and thus it'll be slower and may freeze thw window in browser's javascript. Please consider using prime() instead.
*
* @param {number} bitLength The required bit length for the generated prime
* @param {number} [iterations = 16] The number of iterations for the Miller-Rabin Probabilistic Primality Test
*
* @returns {bigint} A bigint probable prime of bitLength bits.
*/
function primeSync(bitLength, iterations = 16) {
if (bitLength < 1)
throw new RangeError(`bitLength MUST be > 0 and it is ${bitLength}`);
let rnd = _ZERO;
do {
rnd = fromBuffer(randBytesSync(bitLength / 8, true));
} while (!_isProbablyPrime(rnd, iterations));
return rnd;
}
/**
* Returns a cryptographically secure random integer between [min,max]
* @param {bigint} max Returned value will be <= max
* @param {bigint} [min = BigInt(1)] Returned value will be >= min
*
* @returns {bigint} A cryptographically secure random bigint between [min,max]
*/
function randBetween(max, min = _ONE) {
if (max <= min) throw new Error('max must be > min');
const interval = max - min;
let bitLen = bitLength(interval);
let rnd;
do {
let buf = randBits(bitLen);
rnd = fromBuffer(buf);
} while (rnd > interval);
return rnd + min;
}
/**
* Secure random bits for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
*
* @param {number} bitLength The desired number of random bits
* @param {boolean} [forceLength = false] If we want to force the output to have a specific bit length. It basically forces the msb to be 1
*
* @returns {Buffer|Uint8Array} A Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
*/
function randBits(bitLength, forceLength = false) {
if (bitLength < 1)
throw new RangeError(`bitLength MUST be > 0 and it is ${bitLength}`);
const byteLength = Math.ceil(bitLength / 8);
let rndBytes = randBytesSync(byteLength, false);
// Fill with 0's the extra bits
rndBytes[0] = rndBytes[0] & (2 ** (bitLength % 8) - 1);
if (forceLength) {
let mask = (bitLength % 8) ? 2 ** ((bitLength % 8) - 1) : 128;
rndBytes[0] = rndBytes[0] | mask;
}
return rndBytes;
}
/**
* Secure random bytes for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
*
* @param {number} byteLength The desired number of random bytes
* @param {boolean} [forceLength = false] If we want to force the output to have a bit length of 8*byteLength. It basically forces the msb to be 1
*
* @returns {Promise} A promise that resolves to a Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bytes
*/
function randBytes(byteLength, forceLength = false) {
if (byteLength < 1)
throw new RangeError(`byteLength MUST be > 0 and it is ${byteLength}`);
let buf;
{ // browser
return new Promise(function (resolve) {
buf = new Uint8Array(byteLength);
self.crypto.getRandomValues(buf);
// If fixed length is required we put the first bit to 1 -> to get the necessary bitLength
if (forceLength)
buf[0] = buf[0] | 128;
resolve(buf);
});
}
}
/**
* Secure random bytes for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
*
* @param {number} byteLength The desired number of random bytes
* @param {boolean} [forceLength = false] If we want to force the output to have a bit length of 8*byteLength. It basically forces the msb to be 1
*
* @returns {Buffer|Uint8Array} A Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bytes
*/
function randBytesSync(byteLength, forceLength = false) {
if (byteLength < 1)
throw new RangeError(`byteLength MUST be > 0 and it is ${byteLength}`);
let buf;
{ // browser
buf = new Uint8Array(byteLength);
self.crypto.getRandomValues(buf);
}
// If fixed length is required we put the first bit to 1 -> to get the necessary bitLength
if (forceLength)
buf[0] = buf[0] | 128;
return buf;
}
/**
* Finds the smallest positive element that is congruent to a in modulo n
* @param {number|bigint} a An integer
* @param {number|bigint} n The modulo
*
* @returns {bigint} The smallest positive representation of a in modulo n
*/
function toZn(a, n) {
n = BigInt(n);
if (n <= 0)
return NaN;
a = BigInt(a) % n;
return (a < 0) ? a + n : a;
}
/* HELPER FUNCTIONS */
function fromBuffer(buf) {
let ret = _ZERO;
for (let i of buf.values()) {
let bi = BigInt(i);
ret = (ret << BigInt(8)) + bi;
}
return ret;
}
function _isProbablyPrimeWorkerUrl() {
// Let's us first add all the required functions
let workerCode = `'use strict';const _ZERO = BigInt(0);const _ONE = BigInt(1);const _TWO = BigInt(2);const eGcd = ${eGcd.toString()};const modInv = ${modInv.toString()};const modPow = ${modPow.toString()};const toZn = ${toZn.toString()};const randBits = ${randBits.toString()};const randBytesSync = ${randBytesSync.toString()};const randBetween = ${randBetween.toString()};const isProbablyPrime = ${_isProbablyPrime.toString()};${bitLength.toString()}${fromBuffer.toString()}`;
const onmessage = async function (event) { // Let's start once we are called
// event.data = {rnd: <bigint>, iterations: <number>}
const isPrime = await isProbablyPrime(event.data.rnd, event.data.iterations);
postMessage({
'isPrime': isPrime,
'value': event.data.rnd,
'id': event.data.id
});
};
workerCode += `onmessage = ${onmessage.toString()};`;
return _workerUrl(workerCode);
}
function _workerUrl(workerCode) {
workerCode = `(() => {${workerCode}})()`; // encapsulate IIFE
const _blob = new Blob([workerCode], { type: 'text/javascript' });
return window.URL.createObjectURL(_blob);
}
function _isProbablyPrime(w, iterations = 16) {
/*
PREFILTERING. Even values but 2 are not primes, so don't test.
1 is not a prime and the M-R algorithm needs w>1.
*/
if (w === _TWO)
return true;
else if ((w & _ONE) === _ZERO || w === _ONE)
return false;
/*
Test if any of the first 250 small primes are a factor of w. 2 is not tested because it was already tested above.
*/
const firstPrimes = [
3,
5,
7,
11,
13,
17,
19,
23,
29,
31,
37,
41,
43,
47,
53,
59,
61,
67,
71,
73,
79,
83,
89,
97,
101,
103,
107,
109,
113,
127,
131,
137,
139,
149,
151,
157,
163,
167,
173,
179,
181,
191,
193,
197,
199,
211,
223,
227,
229,
233,
239,
241,
251,
257,
263,
269,
271,
277,
281,
283,
293,
307,
311,
313,
317,
331,
337,
347,
349,
353,
359,
367,
373,
379,
383,
389,
397,
401,
409,
419,
421,
431,
433,
439,
443,
449,
457,
461,
463,
467,
479,
487,
491,
499,
503,
509,
521,
523,
541,
547,
557,
563,
569,
571,
577,
587,
593,
599,
601,
607,
613,
617,
619,
631,
641,
643,
647,
653,
659,
661,
673,
677,
683,
691,
701,
709,
719,
727,
733,
739,
743,
751,
757,
761,
769,
773,
787,
797,
809,
811,
821,
823,
827,
829,
839,
853,
857,
859,
863,
877,
881,
883,
887,
907,
911,
919,
929,
937,
941,
947,
953,
967,
971,
977,
983,
991,
997,
1009,
1013,
1019,
1021,
1031,
1033,
1039,
1049,
1051,
1061,
1063,
1069,
1087,
1091,
1093,
1097,
1103,
1109,
1117,
1123,
1129,
1151,
1153,
1163,
1171,
1181,
1187,
1193,
1201,
1213,
1217,
1223,
1229,
1231,
1237,
1249,
1259,
1277,
1279,
1283,
1289,
1291,
1297,
1301,
1303,
1307,
1319,
1321,
1327,
1361,
1367,
1373,
1381,
1399,
1409,
1423,
1427,
1429,
1433,
1439,
1447,
1451,
1453,
1459,
1471,
1481,
1483,
1487,
1489,
1493,
1499,
1511,
1523,
1531,
1543,
1549,
1553,
1559,
1567,
1571,
1579,
1583,
1597,
];
for (let i = 0; i < firstPrimes.length && (BigInt(firstPrimes[i]) <= w); i++) {
const p = BigInt(firstPrimes[i]);
if (w === p)
return true;
else if (w % p === _ZERO)
return false;
}
/*
1. Let a be the largest integer such that 2**a divides w1.
2. m = (w1) / 2**a.
3. wlen = len (w).
4. For i = 1 to iterations do
4.1 Obtain a string b of wlen bits from an RBG.
Comment: Ensure that 1 < b < w1.
4.2 If ((b ≤ 1) or (b ≥ w1)), then go to step 4.1.
4.3 z = b**m mod w.
4.4 If ((z = 1) or (z = w 1)), then go to step 4.7.
4.5 For j = 1 to a 1 do.
4.5.1 z = z**2 mod w.
4.5.2 If (z = w1), then go to step 4.7.
4.5.3 If (z = 1), then go to step 4.6.
4.6 Return COMPOSITE.
4.7 Continue.
Comment: Increment i for the do-loop in step 4.
5. Return PROBABLY PRIME.
*/
let a = _ZERO, d = w - _ONE;
while (d % _TWO === _ZERO) {
d /= _TWO;
++a;
}
let m = (w - _ONE) / (_TWO ** a);
loop: do {
let b = randBetween(w - _ONE, _TWO);
let z = modPow(b, m, w);
if (z === _ONE || z === w - _ONE)
continue;
for (let j = 1; j < a; j++) {
z = modPow(z, _TWO, w);
if (z === w - _ONE)
continue loop;
if (z === _ONE)
break;
}
return false;
} while (--iterations);
return true;
}
export { abs, bitLength, eGcd, gcd, isProbablyPrime, lcm, max, min, modInv, modPow, prime, primeSync, randBetween, randBits, randBytes, randBytesSync, toZn };