X-Git-Url: https://git.immae.eu/?p=perso%2FImmae%2FProjets%2FCryptomonnaies%2FBIP39.git;a=blobdiff_plain;f=src%2Fjs%2Fentropy.js;h=62b271125a4939ac8d2249cd9d1508cadf966ae9;hp=d04d861dfa16b44f23b41398ebaa2418b3b129e1;hb=22f8766947313324c4acda2de4f170475d3c5ded;hpb=87ad2c6e4c7987320d8ce147fe9310b702c5deea diff --git a/src/js/entropy.js b/src/js/entropy.js index d04d861..62b2711 100644 --- a/src/js/entropy.js +++ b/src/js/entropy.js @@ -16,7 +16,7 @@ window.Entropy = new (function() { - var TWO = new BigInteger(2); + var TWO = new libs.BigInteger.BigInteger(2); // matchers returns an array of the matched events for each type of entropy. // eg @@ -67,9 +67,9 @@ window.Entropy = new (function() { return ints; } - this.fromString = function(rawEntropyStr) { + this.fromString = function(rawEntropyStr, baseStr) { // Find type of entropy being used (binary, hex, dice etc) - var base = getBase(rawEntropyStr); + var base = getBase(rawEntropyStr, baseStr); // Convert dice to base6 entropy (ie 1-6 to 0-5) // This is done by changing all 6s to 0s if (base.str == "dice") { @@ -103,11 +103,11 @@ window.Entropy = new (function() { // Convert base.ints to BigInteger. // Due to using unusual bases, eg cards of base52, this is not as simple as // using BigInteger.parse() - var entropyInt = BigInteger.ZERO; + var entropyInt = libs.BigInteger.BigInteger.ZERO; for (var i=base.ints.length-1; i>=0; i--) { - var thisInt = BigInteger.parse(base.ints[i]); + var thisInt = libs.BigInteger.BigInteger.parse(base.ints[i]); var power = (base.ints.length - 1) - i; - var additionalEntropy = BigInteger.parse(base.asInt).pow(power).multiply(thisInt); + var additionalEntropy = libs.BigInteger.BigInteger.parse(base.asInt).pow(power).multiply(thisInt); entropyInt = entropyInt.add(additionalEntropy); } // Convert entropy to binary @@ -120,9 +120,13 @@ window.Entropy = new (function() { while (entropyBin.length < expectedBits) { entropyBin = "0" + entropyBin; } + // Calculate the number of bits per event + var bitsPerEvent = Math.log2(base.asInt); // Cards binary must be handled differently, since they're not replaced if (base.asInt == 52) { - entropyBin = getCardBinary(base.parts); + var cardEntropy = processCardEntropy(base.parts); + entropyBin = cardEntropy.binaryStr; + bitsPerEvent = cardEntropy.bitsPerEvent; } // Supply a 'filtered' entropy string for display purposes var entropyClean = base.parts.join(""); @@ -144,6 +148,7 @@ window.Entropy = new (function() { binaryStr: entropyBin, cleanStr: entropyClean, cleanHtml: entropyHtml, + bitsPerEvent: bitsPerEvent, base: base, } return e; @@ -161,13 +166,14 @@ window.Entropy = new (function() { return s; } - function getBase(str) { + function getBase(str, baseStr) { // Need to get the lowest base for the supplied entropy. // This prevents interpreting, say, dice rolls as hexadecimal. var binaryMatches = matchers.binary(str); var hexMatches = matchers.hex(str); + var autodetect = baseStr === undefined; // Find the lowest base that can be used, whilst ignoring any irrelevant chars - if (binaryMatches.length == hexMatches.length && hexMatches.length > 0) { + if ((binaryMatches.length == hexMatches.length && hexMatches.length > 0 && autodetect) || baseStr === "binary") { var ints = binaryMatches.map(function(i) { return parseInt(i, 2) }); return { ints: ints, @@ -178,7 +184,7 @@ window.Entropy = new (function() { } } var cardMatches = matchers.card(str); - if (cardMatches.length >= hexMatches.length / 2) { + if ((cardMatches.length >= hexMatches.length / 2 && autodetect) || baseStr === "card") { var ints = convertCardsToInts(cardMatches); return { ints: ints, @@ -189,7 +195,7 @@ window.Entropy = new (function() { } } var diceMatches = matchers.dice(str); - if (diceMatches.length == hexMatches.length && hexMatches.length > 0) { + if ((diceMatches.length == hexMatches.length && hexMatches.length > 0 && autodetect) || baseStr === "dice") { var ints = diceMatches.map(function(i) { return parseInt(i) }); return { ints: ints, @@ -200,7 +206,7 @@ window.Entropy = new (function() { } } var base6Matches = matchers.base6(str); - if (base6Matches.length == hexMatches.length && hexMatches.length > 0) { + if ((base6Matches.length == hexMatches.length && hexMatches.length > 0 && autodetect) || baseStr === "base 6") { var ints = base6Matches.map(function(i) { return parseInt(i) }); return { ints: ints, @@ -211,7 +217,7 @@ window.Entropy = new (function() { } } var base10Matches = matchers.base10(str); - if (base10Matches.length == hexMatches.length && hexMatches.length > 0) { + if ((base10Matches.length == hexMatches.length && hexMatches.length > 0 && autodetect) || baseStr === "base 10") { var ints = base10Matches.map(function(i) { return parseInt(i) }); return { ints: ints, @@ -236,7 +242,7 @@ window.Entropy = new (function() { // total possible entropy is measured using n!, not base^n. // eg the second last card can be only one of two, not one of fifty two // so the added entropy for that card is only one bit at most - function getCardBinary(cards) { + function processCardEntropy(cards) { // Track how many instances of each card have been used, and thus // how many decks are in use. var cardCounts = {}; @@ -258,7 +264,12 @@ window.Entropy = new (function() { } // Work out the total number of bits for this many decks // See http://crypto.stackexchange.com/q/41886 - var gainedBits = Math.log2(factorial(52 * numberOfDecks)); + var gainedBits = 0; + // Equivalent of Math.log2(factorial(52*numberOfDecks)) + // which becomes infinity for numberOfDecks > 4 + for (var i=1; i<=52*numberOfDecks; i++) { + gainedBits = gainedBits + Math.log2(i); + } var lostBits = 52 * Math.log2(factorial(numberOfDecks)); var maxBits = gainedBits - lostBits; // Convert the drawn cards to a binary representation. @@ -283,15 +294,12 @@ window.Entropy = new (function() { // Create a normalized string of the selected cards var normalizedCards = cards.join("").toUpperCase(); // Convert to binary using the SHA256 hash of the normalized cards. - // If the number of bits is more than 256, multiple rounds of hashing + // If the number of bits is more than 256, multiple hashes // are used until the required number of bits is reached. var entropyBin = ""; var iterations = 0; while (entropyBin.length < numberOfBits) { - var hashedCards = sjcl.hash.sha256.hash(normalizedCards); - for (var j=0; j