randBitsSync

README.md

@@ -226,6 +226,116 @@ Finds the smallest positive element that is congruent to a in modulo n
 | a | <code>number</code> \| <code>bigint</code> | An integer |
 | n | <code>number</code> \| <code>bigint</code> | The modulo |
 
+<a name="isProbablyPrime"></a>
+
+### isProbablyPrime(w, [iterations]) ⇒ <code>Promise.&lt;boolean&gt;</code>
+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)
+
+**Kind**: global function  
+**Returns**: <code>Promise.&lt;boolean&gt;</code> - A promise that resolves to a boolean that is either true (a probably prime number) or false (definitely composite)  
+
+| Param | Type | Default | Description |
+| --- | --- | --- | --- |
+| w | <code>number</code> \| <code>bigint</code> |  | An integer to be tested for primality |
+| [iterations] | <code>number</code> | <code>16</code> | The number of iterations for the primality test. The value shall be consistent with Table C.1, C.2 or C.3 |
+
+<a name="prime"></a>
+
+### prime(bitLength, [iterations]) ⇒ <code>Promise.&lt;bigint&gt;</code>
+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).
+
+**Kind**: global function  
+**Returns**: <code>Promise.&lt;bigint&gt;</code> - A promise that resolves to a bigint probable prime of bitLength bits.  
+
+| Param | Type | Default | Description |
+| --- | --- | --- | --- |
+| bitLength | <code>number</code> |  | The required bit length for the generated prime |
+| [iterations] | <code>number</code> | <code>16</code> | The number of iterations for the Miller-Rabin Probabilistic Primality Test |
+
+<a name="primeSync"></a>
+
+### primeSync(bitLength, [iterations]) ⇒ <code>bigint</code>
+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.
+
+**Kind**: global function  
+**Returns**: <code>bigint</code> - A bigint probable prime of bitLength bits.  
+
+| Param | Type | Default | Description |
+| --- | --- | --- | --- |
+| bitLength | <code>number</code> |  | The required bit length for the generated prime |
+| [iterations] | <code>number</code> | <code>16</code> | The number of iterations for the Miller-Rabin Probabilistic Primality Test |
+
+<a name="randBetween"></a>
+
+### randBetween(max, [min]) ⇒ <code>bigint</code>
+Returns a cryptographically secure random integer between [min,max]
+
+**Kind**: global function  
+**Returns**: <code>bigint</code> - A cryptographically secure random bigint between [min,max]  
+
+| Param | Type | Default | Description |
+| --- | --- | --- | --- |
+| max | <code>bigint</code> |  | Returned value will be <= max |
+| [min] | <code>bigint</code> | <code>BigInt(1)</code> | Returned value will be >= min |
+
+<a name="randBits"></a>
+
+### randBits(bitLength, [forceLength]) ⇒ <code>Promise.&lt;(Buffer\|Uint8Array)&gt;</code>
+Secure random bits for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
+
+**Kind**: global function  
+**Returns**: <code>Promise.&lt;(Buffer\|Uint8Array)&gt;</code> - A Promise that resolves to a Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits  
+
+| Param | Type | Default | Description |
+| --- | --- | --- | --- |
+| bitLength | <code>number</code> |  | The desired number of random bits |
+| [forceLength] | <code>boolean</code> | <code>false</code> | If we want to force the output to have a specific bit length. It basically forces the msb to be 1 |
+
+<a name="randBitsSync"></a>
+
+### randBitsSync(bitLength, [forceLength]) ⇒ <code>Buffer</code> \| <code>Uint8Array</code>
+Secure random bits for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
+
+**Kind**: global function  
+**Returns**: <code>Buffer</code> \| <code>Uint8Array</code> - A Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits  
+
+| Param | Type | Default | Description |
+| --- | --- | --- | --- |
+| bitLength | <code>number</code> |  | The desired number of random bits |
+| [forceLength] | <code>boolean</code> | <code>false</code> | If we want to force the output to have a specific bit length. It basically forces the msb to be 1 |
+
+<a name="randBytes"></a>
+
+### randBytes(byteLength, [forceLength]) ⇒ <code>Promise.&lt;(Buffer\|Uint8Array)&gt;</code>
+Secure random bytes for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
+
+**Kind**: global function  
+**Returns**: <code>Promise.&lt;(Buffer\|Uint8Array)&gt;</code> - A promise that resolves to a Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bytes  
+
+| Param | Type | Default | Description |
+| --- | --- | --- | --- |
+| byteLength | <code>number</code> |  | The desired number of random bytes |
+| [forceLength] | <code>boolean</code> | <code>false</code> | If we want to force the output to have a bit length of 8*byteLength. It basically forces the msb to be 1 |
+
+<a name="randBytesSync"></a>
+
+### randBytesSync(byteLength, [forceLength]) ⇒ <code>Buffer</code> \| <code>Uint8Array</code>
+Secure random bytes for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
+
+**Kind**: global function  
+**Returns**: <code>Buffer</code> \| <code>Uint8Array</code> - A Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bytes  
+
+| Param | Type | Default | Description |
+| --- | --- | --- | --- |
+| byteLength | <code>number</code> |  | The desired number of random bytes |
+| [forceLength] | <code>boolean</code> | <code>false</code> | If we want to force the output to have a bit length of 8*byteLength. It basically forces the msb to be 1 |
+
 <a name="egcdReturn"></a>
 
 ### egcdReturn : <code>Object</code>

build/build.docs.js

@@ -8,17 +8,19 @@ const pkgJson = require('../package.json')
 const rootDir = path.join(__dirname, '..')
 
 const template = path.join(rootDir, pkgJson.directories.src, 'doc', 'readme-template.md')
-const input = path.join(rootDir, pkgJson.directories.lib, 'index.node.js')
+const input = path.join(rootDir, pkgJson.directories.lib, 'index.browser.bundle.mod.js')
+const source = fs.readFileSync(input, { encoding: 'UTF-8' }).replace(/([0-9]+)n([,\s\n)])/g, '$1$2')
 
 const options = {
-  source: fs.readFileSync(input, { encoding: 'UTF-8' }), // we need to use this instead of files in order to avoid issues with esnext features
+  source, // we need to use this instead of files in order to avoid issues with esnext features
   template: fs.readFileSync(template, { encoding: 'UTF-8' }),
   'heading-depth': 3, // The initial heading depth. For example, with a value of 2 the top-level markdown headings look like "## The heading"
   'global-index-format': 'none' // none, grouped, table, dl.
 }
 
+jsdoc2md.clear().then(() => {
   const readmeContents = jsdoc2md.renderSync(options)
 
   const readmeFile = path.join(rootDir, 'README.md')
-
   fs.writeFileSync(readmeFile, readmeContents)
+})

build/rollup.config.js

@@ -29,7 +29,7 @@ module.exports = [
     input: input,
     output: [
       {
-        file: path.join(dstDir, 'index.browser.mod.js'),
+        file: path.join(rootDir, pkgJson.browser),
         format: 'esm'
       }
     ],
@@ -46,7 +46,17 @@ module.exports = [
       {
         file: path.join(dstDir, 'index.browser.bundle.js'),
         format: 'iife',
-        name: pkgCamelisedName
+        name: pkgCamelisedName,
+        plugins: [
+          terser()
+        ]
+      },
+      {
+        file: path.join(dstDir, 'index.browser.bundle.min.mod.js'),
+        format: 'es',
+        plugins: [
+          terser()
+        ]
       },
       {
         file: path.join(dstDir, 'index.browser.bundle.mod.js'),
@@ -59,10 +69,6 @@ module.exports = [
       }),
       resolve({
         browser: true
-      }),
-      terser({
-        // mangle: false,
-        // compress: false
       })
     ]
   },

lib/index.browser.mod.js

@@ -65,7 +65,7 @@ function prime (bitLength, iterations = 16) {
         }
         resolve(msg.value)
       } else { // if a composite is found, make the worker test another random number
-        const buf = randBits(bitLength, true)
+        const buf = randBitsSync(bitLength, true)
         const rnd = fromBuffer(buf)
         try {
           newWorker.postMessage({
@@ -89,7 +89,7 @@ function prime (bitLength, iterations = 16) {
     }
     /* eslint-enable no-lone-blocks */
     for (let i = 0; i < workerList.length; i++) {
-      const buf = randBits(bitLength, true)
+      const buf = randBitsSync(bitLength, true)
       const rnd = fromBuffer(buf)
       workerList[i].postMessage({
         rnd: rnd,
@@ -131,12 +131,40 @@ function randBetween (max, min = 1n) {
   const bitLen = bitLength(interval)
   let rnd
   do {
-    const buf = randBits(bitLen)
+    const buf = randBitsSync(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 {Promise<Buffer | Uint8Array>} A Promise that resolves to a Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
+ */
+async 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)
+  const bitLengthMod8 = bitLength % 8
+
+  const rndBytes = await randBytes(byteLength, false)
+  if (bitLengthMod8) {
+    // Fill with 0's the extra bits
+    rndBytes[0] = rndBytes[0] & (2 ** bitLengthMod8 - 1)
+  }
+  if (forceLength) {
+    const mask = bitLengthMod8 ? 2 ** (bitLengthMod8 - 1) : 128
+    rndBytes[0] = rndBytes[0] | mask
+  }
+  return rndBytes
+}
+
 /**
  * Secure random bits for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
  *
@@ -145,7 +173,7 @@ function randBetween (max, min = 1n) {
  *
  * @returns {Buffer | Uint8Array} A Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
  */
-function randBits (bitLength, forceLength = false) {
+function randBitsSync (bitLength, forceLength = false) {
   if (bitLength < 1) {
     throw new RangeError(`bitLength MUST be > 0 and it is ${bitLength}`)
   }
@@ -175,18 +203,17 @@ function randBits (bitLength, forceLength = false) {
 function randBytes (byteLength, forceLength = false) {
   if (byteLength < 1) { throw new RangeError(`byteLength MUST be > 0 and it is ${byteLength}`) }
 
-  let buf
   /* eslint-disable no-lone-blocks */
   { // browser
     return new Promise(function (resolve) {
-      buf = new Uint8Array(byteLength)
+      const 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)
     })
   }
-  /* eslint-disable no-lone-blocks */
+  /* eslint-enable no-lone-blocks */
 }
 
 /**
@@ -200,15 +227,16 @@ function randBytes (byteLength, forceLength = false) {
 function randBytesSync (byteLength, forceLength = false) {
   if (byteLength < 1) { throw new RangeError(`byteLength MUST be > 0 and it is ${byteLength}`) }
 
-  let buf
+  /* eslint-disable no-lone-blocks */
   { // browser
-    buf = new Uint8Array(byteLength)
+    const 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
   }
+  /* eslint-enable no-lone-blocks */
+}
 
 /* HELPER FUNCTIONS */
 
@@ -223,7 +251,7 @@ function fromBuffer (buf) {
 
 function _isProbablyPrimeWorkerUrl () {
   // Let's us first add all the required functions
-  let workerCode = `'use strict';const ${eGcd.name}=${eGcd.toString()};const ${modInv.name}=${modInv.toString()};const ${modPow.name}=${modPow.toString()};const ${toZn.name}=${toZn.toString()};const ${randBits.name}=${randBits.toString()};const ${randBytesSync.name}=${randBytesSync.toString()};const ${randBetween.name}=${randBetween.toString()};const ${isProbablyPrime.name}=${_isProbablyPrime.toString()};${bitLength.toString()}${fromBuffer.toString()}`
+  let workerCode = `'use strict';const ${eGcd.name}=${eGcd.toString()};const ${modInv.name}=${modInv.toString()};const ${modPow.name}=${modPow.toString()};const ${toZn.name}=${toZn.toString()};const ${randBitsSync.name}=${randBitsSync.toString()};const ${randBytesSync.name}=${randBytesSync.toString()};const ${randBetween.name}=${randBetween.toString()};const ${isProbablyPrime.name}=${_isProbablyPrime.toString()};${bitLength.toString()}${fromBuffer.toString()}`
 
   const onmessage = async function (event) { // Let's start once we are called
     // event.data = {rnd: <bigint>, iterations: <number>}
@@ -581,4 +609,4 @@ function _isProbablyPrime (w, iterations = 16) {
   return true
 }
 
-export { isProbablyPrime, prime, primeSync, randBetween, randBits, randBytes, randBytesSync }
+export { isProbablyPrime, prime, primeSync, randBetween, randBits, randBitsSync, randBytes, randBytesSync }

lib/index.node.js

@@ -82,7 +82,7 @@ function prime (bitLength, iterations = 16) {
         }
         resolve(msg.value)
       } else { // if a composite is found, make the worker test another random number
-        const buf = randBits(bitLength, true)
+        const buf = randBitsSync(bitLength, true)
         const rnd = fromBuffer(buf)
         try {
           newWorker.postMessage({
@@ -107,7 +107,7 @@ function prime (bitLength, iterations = 16) {
     }
     /* eslint-enable no-lone-blocks */
     for (let i = 0; i < workerList.length; i++) {
-      const buf = randBits(bitLength, true)
+      const buf = randBitsSync(bitLength, true)
       const rnd = fromBuffer(buf)
       workerList[i].postMessage({
         rnd: rnd,
@@ -149,12 +149,40 @@ function randBetween (max, min = 1n) {
   const bitLen = bigintModArith.bitLength(interval)
   let rnd
   do {
-    const buf = randBits(bitLen)
+    const buf = randBitsSync(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 {Promise<Buffer | Uint8Array>} A Promise that resolves to a Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
+ */
+async 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)
+  const bitLengthMod8 = bitLength % 8
+
+  const rndBytes = await randBytes(byteLength, false)
+  if (bitLengthMod8) {
+    // Fill with 0's the extra bits
+    rndBytes[0] = rndBytes[0] & (2 ** bitLengthMod8 - 1)
+  }
+  if (forceLength) {
+    const mask = bitLengthMod8 ? 2 ** (bitLengthMod8 - 1) : 128
+    rndBytes[0] = rndBytes[0] | mask
+  }
+  return rndBytes
+}
+
 /**
  * Secure random bits for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
  *
@@ -163,7 +191,7 @@ function randBetween (max, min = 1n) {
  *
  * @returns {Buffer | Uint8Array} A Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
  */
-function randBits (bitLength, forceLength = false) {
+function randBitsSync (bitLength, forceLength = false) {
   if (bitLength < 1) {
     throw new RangeError(`bitLength MUST be > 0 and it is ${bitLength}`)
   }
@@ -193,18 +221,17 @@ function randBits (bitLength, forceLength = false) {
 function randBytes (byteLength, forceLength = false) {
   if (byteLength < 1) { throw new RangeError(`byteLength MUST be > 0 and it is ${byteLength}`) }
 
-  let buf
   /* eslint-disable no-lone-blocks */
   { // node
     const crypto = require('crypto')
-    buf = Buffer.alloc(byteLength)
+    const buf = Buffer.alloc(byteLength)
     return crypto.randomFill(buf, function (resolve) {
       // 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)
     })
   }
-  /* eslint-disable no-lone-blocks */
+  /* eslint-enable no-lone-blocks */
 }
 
 /**
@@ -218,16 +245,17 @@ function randBytes (byteLength, forceLength = false) {
 function randBytesSync (byteLength, forceLength = false) {
   if (byteLength < 1) { throw new RangeError(`byteLength MUST be > 0 and it is ${byteLength}`) }
 
-  let buf
+  /* eslint-disable no-lone-blocks */
   { // node
     const crypto = require('crypto')
-    buf = Buffer.alloc(byteLength)
+    const buf = Buffer.alloc(byteLength)
     crypto.randomFillSync(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
   }
+  /* eslint-enable no-lone-blocks */
+}
 
 /* HELPER FUNCTIONS */
 
@@ -576,6 +604,7 @@ function _isProbablyPrime (w, iterations = 16) {
 }
 
 let _useWorkers = true // The following is just to check whether Node.js can use workers
+/* eslint-disable no-lone-blocks */
 { // Node.js
   _useWorkers = (function _workers () {
     try {
@@ -590,6 +619,7 @@ This node version doesn't support worker_threads. You should enable them in orde
     }
   })()
 }
+/* eslint-enable no-lone-blocks */
 
 if (_useWorkers) { // node.js with support for workers
   const { parentPort, isMainThread } = require('worker_threads')
@@ -671,5 +701,6 @@ exports.prime = prime
 exports.primeSync = primeSync
 exports.randBetween = randBetween
 exports.randBits = randBits
+exports.randBitsSync = randBitsSync
 exports.randBytes = randBytes
 exports.randBytesSync = randBytesSync

package.json

@@ -53,7 +53,7 @@
     "ignore": [
       "/test/browser/",
       "/lib/index.browser.bundle.js",
-      "/lib/index.browser.bundle.mod.js"
+      "/lib/index.browser.bundle.min.mod.js"
     ]
   },
   "devDependencies": {

src/js/index.js

@@ -8,9 +8,9 @@ export { abs, bitLength, eGcd, gcd, lcm, max, min, modInv, modPow, toZn } from '
  * @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<boolean>} A promise that resolves to a boolean that is either true (a probably prime number) or false (definitely composite)
+ * @returns {Promise<boolean>} A promise that resolves to a boolean that is either true (a probably prime number) or false (definitely composite)
  */
-export async function isProbablyPrime (w, iterations = 16) {
+export function isProbablyPrime (w, iterations = 16) {
   if (typeof w === 'number') {
     w = BigInt(w)
   }
@@ -98,7 +98,7 @@ export function prime (bitLength, iterations = 16) {
         }
         resolve(msg.value)
       } else { // if a composite is found, make the worker test another random number
-        const buf = randBits(bitLength, true)
+        const buf = randBitsSync(bitLength, true)
         const rnd = fromBuffer(buf)
         try {
           newWorker.postMessage({
@@ -130,7 +130,7 @@ export function prime (bitLength, iterations = 16) {
     }
     /* eslint-enable no-lone-blocks */
     for (let i = 0; i < workerList.length; i++) {
-      const buf = randBits(bitLength, true)
+      const buf = randBitsSync(bitLength, true)
       const rnd = fromBuffer(buf)
       workerList[i].postMessage({
         rnd: rnd,
@@ -172,12 +172,40 @@ export function randBetween (max, min = 1n) {
   const bitLen = bitLength(interval)
   let rnd
   do {
-    const buf = randBits(bitLen)
+    const buf = randBitsSync(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 {Promise<Buffer | Uint8Array>} A Promise that resolves to a Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
+ */
+export async 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)
+  const bitLengthMod8 = bitLength % 8
+
+  const rndBytes = await randBytes(byteLength, false)
+  if (bitLengthMod8) {
+    // Fill with 0's the extra bits
+    rndBytes[0] = rndBytes[0] & (2 ** bitLengthMod8 - 1)
+  }
+  if (forceLength) {
+    const mask = bitLengthMod8 ? 2 ** (bitLengthMod8 - 1) : 128
+    rndBytes[0] = rndBytes[0] | mask
+  }
+  return rndBytes
+}
+
 /**
  * Secure random bits for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
  *
@@ -186,7 +214,7 @@ export function randBetween (max, min = 1n) {
  *
  * @returns {Buffer | Uint8Array} A Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
  */
-export function randBits (bitLength, forceLength = false) {
+export function randBitsSync (bitLength, forceLength = false) {
   if (bitLength < 1) {
     throw new RangeError(`bitLength MUST be > 0 and it is ${bitLength}`)
   }
@@ -216,11 +244,10 @@ export function randBits (bitLength, forceLength = false) {
 export function randBytes (byteLength, forceLength = false) {
   if (byteLength < 1) { throw new RangeError(`byteLength MUST be > 0 and it is ${byteLength}`) }
 
-  let buf
   /* eslint-disable no-lone-blocks */
   if (!process.browser) { // node
     const crypto = require('crypto')
-    buf = Buffer.alloc(byteLength)
+    const buf = Buffer.alloc(byteLength)
     return crypto.randomFill(buf, function (resolve) {
       // If fixed length is required we put the first bit to 1 -> to get the necessary bitLength
       if (forceLength) { buf[0] = buf[0] | 128 }
@@ -228,14 +255,14 @@ export function randBytes (byteLength, forceLength = false) {
     })
   } else { // browser
     return new Promise(function (resolve) {
-      buf = new Uint8Array(byteLength)
+      const 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)
     })
   }
-  /* eslint-disable no-lone-blocks */
+  /* eslint-enable no-lone-blocks */
 }
 
 /**
@@ -249,18 +276,22 @@ export function randBytes (byteLength, forceLength = false) {
 export function randBytesSync (byteLength, forceLength = false) {
   if (byteLength < 1) { throw new RangeError(`byteLength MUST be > 0 and it is ${byteLength}`) }
 
-  let buf
+  /* eslint-disable no-lone-blocks */
   if (!process.browser) { // node
     const crypto = require('crypto')
-    buf = Buffer.alloc(byteLength)
+    const buf = Buffer.alloc(byteLength)
     crypto.randomFillSync(buf)
-  } else { // 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
+  } else { // browser
+    const 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
+  }
+  /* eslint-enable no-lone-blocks */
 }
 
 /* HELPER FUNCTIONS */
@@ -276,7 +307,7 @@ function fromBuffer (buf) {
 
 function _isProbablyPrimeWorkerUrl () {
   // Let's us first add all the required functions
-  let workerCode = `'use strict';const ${eGcd.name}=${eGcd.toString()};const ${modInv.name}=${modInv.toString()};const ${modPow.name}=${modPow.toString()};const ${toZn.name}=${toZn.toString()};const ${randBits.name}=${randBits.toString()};const ${randBytesSync.name}=${randBytesSync.toString()};const ${randBetween.name}=${randBetween.toString()};const ${isProbablyPrime.name}=${_isProbablyPrime.toString()};${bitLength.toString()}${fromBuffer.toString()}`
+  let workerCode = `'use strict';const ${eGcd.name}=${eGcd.toString()};const ${modInv.name}=${modInv.toString()};const ${modPow.name}=${modPow.toString()};const ${toZn.name}=${toZn.toString()};const ${randBitsSync.name}=${randBitsSync.toString()};const ${randBytesSync.name}=${randBytesSync.toString()};const ${randBetween.name}=${randBetween.toString()};const ${isProbablyPrime.name}=${_isProbablyPrime.toString()};${bitLength.toString()}${fromBuffer.toString()}`
 
   const onmessage = async function (event) { // Let's start once we are called
     // event.data = {rnd: <bigint>, iterations: <number>}
@@ -635,6 +666,7 @@ function _isProbablyPrime (w, iterations = 16) {
 }
 
 let _useWorkers = true // The following is just to check whether Node.js can use workers
+/* eslint-disable no-lone-blocks */
 if (!process.browser) { // Node.js
   _useWorkers = (function _workers () {
     try {
@@ -649,6 +681,7 @@ This node version doesn't support worker_threads. You should enable them in orde
     }
   })()
 }
+/* eslint-enable no-lone-blocks */
 
 if (!process.browser && _useWorkers) { // node.js with support for workers
   const { parentPort, isMainThread } = require('worker_threads')

types/index.d.ts

@@ -39,6 +39,15 @@ export function primeSync(bitLength: number, iterations?: number): bigint;
  * @returns {bigint} A cryptographically secure random bigint between [min,max]
  */
 export function randBetween(max: bigint, min?: bigint): bigint;
+/**
+ * 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 {Promise<Buffer | Uint8Array>} A Promise that resolves to a Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
+ */
+export function randBits(bitLength: number, forceLength?: boolean): Promise<Uint8Array | Buffer>;
 /**
  * Secure random bits for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
  *
@@ -47,7 +56,7 @@ export function randBetween(max: bigint, min?: bigint): bigint;
  *
  * @returns {Buffer | Uint8Array} A Buffer/UInt8Array (Node.js/Browser) filled with cryptographically secure random bits
  */
-export function randBits(bitLength: number, forceLength?: boolean): Uint8Array | Buffer;
+export function randBitsSync(bitLength: number, forceLength?: boolean): Uint8Array | Buffer;
 /**
  * Secure random bytes for both node and browsers. Node version uses crypto.randomFill() and browser one self.crypto.getRandomValues()
  *