Add bitLen to Entropy class

dingosky · dingosky · commit 2240349b5618 · 2018-04-19T10:24:25.000-07:00
Allows string creation of default bit len
diff --git a/dist/lib/entropy.js b/dist/lib/entropy.js
@@ -5,10 +5,6 @@ Object.defineProperty(exports, "__esModule", {
 });
 exports.charset2 = exports.charset4 = exports.charset8 = exports.charset16 = exports.charset32 = exports.charset64 = undefined;
 
-var _log = require('babel-runtime/core-js/math/log2');
-
-var _log2 = _interopRequireDefault(_log);
-
 var _classCallCheck2 = require('babel-runtime/helpers/classCallCheck');
 
 var _classCallCheck3 = _interopRequireDefault(_classCallCheck2);
@@ -17,6 +13,10 @@ var _createClass2 = require('babel-runtime/helpers/createClass');
 
 var _createClass3 = _interopRequireDefault(_createClass2);
 
+var _log = require('babel-runtime/core-js/math/log2');
+
+var _log2 = _interopRequireDefault(_log);
+
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
 var Crypto = require('crypto');
@@ -103,22 +103,63 @@ var randomBytes = function randomBytes(count) {
   return buffer;
 };
 
+var entropyBits = function entropyBits(total, risk) {
+  if (total === 0) {
+    return 0;
+  }
+  var log2 = _log2.default;
+
+  var N = void 0;
+  if (total < 1000) {
+    N = log2(total) + log2(total - 1);
+  } else {
+    N = 2 * log2(total);
+  }
+  return N + log2(risk) - 1;
+};
+
+var createCharset = function createCharset(arg) {
+  if (arg instanceof CharSet) {
+    return arg;
+  } else if (typeof arg === 'string' || arg instanceof String) {
+    return new CharSet(arg);
+  }
+  return charset32;
+};
+
 var _class = function () {
-  function _class(arg) {
+  function _class() {
+    var arg = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : { bits: 128, charset: CharSet.charset32 };
     (0, _classCallCheck3.default)(this, _class);
 
     var charset = void 0;
-    if (arg === undefined) {
-      charset = charset32;
-    } else if (arg instanceof CharSet) {
-      charset = arg;
-    } else if (typeof arg === 'string' || arg instanceof String) {
-      charset = new CharSet(arg);
+    var bitLen = 0;
+
+    if (arg instanceof CharSet || arg instanceof String || typeof arg === 'string') {
+      charset = createCharset(arg);
+    } else if (arg instanceof Object) {
+      if (typeof arg.bits === 'number') {
+        bitLen = arg.bits;
+      } else if (typeof arg.total === 'number' && typeof arg.risk === 'number') {
+        bitLen = entropyBits(arg.total, arg.risk);
+      } else {
+        throw new Error('Entropy params must include either bits or both total and risk');
+      }
+      charset = createCharset(arg.charset);
     } else {
-      throw new Error('Invalid arg: must be either valid CharSet or valid chars');
+      throw new Error('Constructor arg must either be a valid CharSet, valid characters, or valid Entropy params');
+    }
+
+    if (charset === undefined) {
+      throw new Error('Invalid constructor CharSet declaration');
+    } else if (bits < 0) {
+      throw new Error('Invalid constructor declaration of bits less than zero');
     }
+
     var hideProps = {
-      charset: charset
+      charset: charset,
+      bitLen: bitLen,
+      bytesNeeded: charset.bytesNeeded(bitLen)
     };
     propMap.set(this, hideProps);
   }
@@ -160,9 +201,18 @@ var _class = function () {
     }
   }, {
     key: 'string',
-    value: function string(bitLen) {
+    value: function string() {
+      var bitLen = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : undefined;
       var charset = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : propMap.get(this).charset;
 
+      if (bitLen === undefined) {
+        var _propMap$get = propMap.get(this),
+            classCharset = _propMap$get.charset,
+            classBitLen = _propMap$get.bitLen,
+            _bytesNeeded = _propMap$get.bytesNeeded;
+
+        return this.stringWithBytes(classBitLen, cryptoBytes(_bytesNeeded), classCharset);
+      }
       var bytesNeeded = charset.bytesNeeded(bitLen);
       return this.stringWithBytes(bitLen, cryptoBytes(bytesNeeded), charset);
     }
@@ -193,6 +243,11 @@ var _class = function () {
     value: function chars() {
       return propMap.get(this).charset.chars();
     }
+  }, {
+    key: 'bits',
+    value: function bits() {
+      return propMap.get(this).bitLen;
+    }
   }, {
     key: 'use',
     value: function use(charset) {
@@ -212,20 +267,7 @@ var _class = function () {
   }], [{
     key: 'bits',
     value: function bits(total, risk) {
-      if (total === 0) {
-        return 0;
-      }
-
-      var log2 = _log2.default;
-
-
-      var N = void 0;
-      if (total < 1000) {
-        N = log2(total) + log2(total - 1);
-      } else {
-        N = 2 * log2(total);
-      }
-      return N + log2(risk) - 1;
+      return entropyBits(total, risk);
     }
   }]);
   return _class;
diff --git a/lib/entropy.js b/lib/entropy.js
@@ -75,38 +75,63 @@ const randomBytes = (count) => {
   return buffer
 }
 
+const entropyBits = (total, risk) => {
+  if (total === 0) { return 0 }
+  const { log2 } = Math
+  let N
+  if (total < 1000) {
+    N = log2(total) + log2(total - 1)
+  } else {
+    N = 2 * log2(total)
+  }
+  return (N + log2(risk)) - 1
+}
+
+const createCharset = (arg) => {
+  if (arg instanceof CharSet) {
+    return arg
+  } else if ((typeof arg === 'string' || arg instanceof String)) {
+    return new CharSet(arg)
+  }
+  return charset32
+}
+
 export default class {
-  constructor(arg) {
+  constructor(arg = { bits: 128, charset: charset32 }) {
     let charset
-    if (arg === undefined) {
-      charset = charset32
-    } else if (arg instanceof CharSet) {
-      charset = arg
-    } else if ((typeof arg === 'string' || arg instanceof String)) {
-      charset = new CharSet(arg)
+    let bitLen = 0
+
+    if (arg instanceof CharSet || arg instanceof String || typeof arg === 'string') {
+      charset = createCharset(arg)
+    } else if (arg instanceof Object) {
+      const { round } = Math
+      if (typeof arg.bits === 'number') {
+        bitLen = round(arg.bits)
+      } else if (typeof arg.total === 'number' && typeof arg.risk === 'number') {
+        bitLen = round(entropyBits(arg.total, arg.risk))
+      } else {
+        throw new Error('Entropy params must include either bits or both total and risk')
+      }
+      charset = createCharset(arg.charset)
     } else {
-      throw new Error('Invalid arg: must be either valid CharSet or valid chars')
-    }
-    const hideProps = {
-      charset
+      throw new Error('Constructor arg must either be a valid CharSet, valid characters, or valid Entropy params')
     }
-    propMap.set(this, hideProps)
-  }
-
-  static bits(total, risk) {
-    if (total === 0) { return 0 }
 
-    const { log2 } = Math
-
-    let N
-    if (total < 1000) {
-      N = log2(total) + log2(total - 1)
-    } else {
-      N = 2 * log2(total)
+    if (charset === undefined) {
+      throw new Error('Invalid constructor CharSet declaration')
+    } else if (bitLen < 0) {
+      throw new Error('Invalid constructor declaration of bits less than zero')
     }
-    return (N + log2(risk)) - 1
+
+    propMap.set(this, {
+      charset,
+      bitLen,
+      bytesNeeded: charset.bytesNeeded(bitLen)
+    })
   }
 
+  static bits(total, risk) { return entropyBits(total, risk) }
+
   smallID(charset = propMap.get(this).charset) {
     return this.string(29, charset)
   }
@@ -127,28 +152,39 @@ export default class {
     return this.string(256, charset)
   }
 
-  string(bitLen, charset = propMap.get(this).charset) {
+  string(bitLen = propMap.get(this).bitLen, charset = propMap.get(this).charset) {
     const bytesNeeded = charset.bytesNeeded(bitLen)
     return this.stringWithBytes(bitLen, cryptoBytes(bytesNeeded), charset)
   }
 
-  stringRandom(bitLen, charset = propMap.get(this).charset) {
+  stringPRNG(bitLen = propMap.get(this).bitLen, charset = propMap.get(this).charset) {
     const bytesNeeded = charset.bytesNeeded(bitLen)
     return this.stringWithBytes(bitLen, randomBytes(bytesNeeded), charset)
   }
 
+  /**
+   * @deprecated Since version 3.1. Will be deleted in version 4.0. Use stringPRNG instead.
+  */
+  stringRandom(bitLen = propMap.get(this).bitLen, charset = propMap.get(this).charset) {
+    return this.stringPRNG(bitLen, charset)
+  }
+
   stringWithBytes(bitLen, bytes, charset = propMap.get(this).charset) {
     return stringWithBytes(bitLen, bytes, charset)
   }
 
-  bytesNeeded(bitLen, charset = propMap.get(this).charset) {
+  bytesNeeded(bitLen = propMap.get(this).bitLen, charset = propMap.get(this).charset) {
     return charset.bytesNeeded(bitLen)
   }
 
   chars() {
     return propMap.get(this).charset.chars()
   }
 
+  bits() {
+    return propMap.get(this).bitLen
+  }
+
   use(charset) {
     if (!(charset instanceof CharSet)) { throw new Error('Invalid CharSet') }
     propMap.get(this).charset = charset
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "entropy-string",
-  "version": "3.0.2",
+  "version": "3.1.0",
   "description": "Efficiently generate cryptographically strong random strings of specified entropy from various character sets.",
   "main": "entropy-string.js",
   "directories": {
diff --git a/test/entropy.js b/test/entropy.js

Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`	`2`	`"name": "entropy-string",`
`3`		`- "version": "3.0.2",`
	`3`	`+ "version": "3.1.0",`
`4`	`4`	`"description": "Efficiently generate cryptographically strong random strings of specified entropy from various character sets.",`
`5`	`5`	`"main": "entropy-string.js",`
`6`	`6`	`"directories": {`