X-Git-Url: https://git.immae.eu/?a=blobdiff_plain;f=src%2Fjs%2Fentropy.js;h=3b62e1062a7a1ca89b126b4bd979d28ca80dbf03;hb=bf96267f89d18f278e78cf02c97ab1e7513fb871;hp=c28620adcf115f2961f51b715d5b144a6a42fe0b;hpb=b6dbc2a1aea8eeab2d41a4d44f9d7522ecc59a50;p=perso%2FImmae%2FProjets%2FCryptomonnaies%2FBIP39.git diff --git a/src/js/entropy.js b/src/js/entropy.js index c28620a..3b62e10 100644 --- a/src/js/entropy.js +++ b/src/js/entropy.js @@ -7,6 +7,7 @@ * dice 6 [1-6] * decimal [0-9] * hexadecimal [0-9A-F] + * card [A2-9TJQK][CDHS] * * Automatically uses lowest entropy to avoid issues such as interpretting 0101 * as hexadecimal which would be 16 bits when really it's only 4 bits of binary @@ -15,6 +16,137 @@ window.Entropy = new (function() { + let eventBits = { + + "binary": { + "0": "0", + "1": "1", + }, + + // log2(6) = 2.58496 bits per roll, with bias + // 4 rolls give 2 bits each + // 2 rolls give 1 bit each + // Average (4*2 + 2*1) / 6 = 1.66 bits per roll without bias + "base 6": { + "0": "00", + "1": "01", + "2": "10", + "3": "11", + "4": "0", + "5": "1", + }, + + // log2(6) = 2.58496 bits per roll, with bias + // 4 rolls give 2 bits each + // 2 rolls give 1 bit each + // Average (4*2 + 2*1) / 6 = 1.66 bits per roll without bias + "base 6 (dice)": { + "0": "00", // equivalent to 0 in base 6 + "1": "01", + "2": "10", + "3": "11", + "4": "0", + "5": "1", + }, + + // log2(10) = 3.321928 bits per digit, with bias + // 8 digits give 3 bits each + // 2 digits give 1 bit each + // Average (8*3 + 2*1) / 10 = 2.6 bits per digit without bias + "base 10": { + "0": "000", + "1": "001", + "2": "010", + "3": "011", + "4": "100", + "5": "101", + "6": "110", + "7": "111", + "8": "0", + "9": "1", + }, + + "hexadecimal": { + "0": "0000", + "1": "0001", + "2": "0010", + "3": "0011", + "4": "0100", + "5": "0101", + "6": "0110", + "7": "0111", + "8": "1000", + "9": "1001", + "a": "1010", + "b": "1011", + "c": "1100", + "d": "1101", + "e": "1110", + "f": "1111", + }, + + // log2(52) = 5.7004 bits per card, with bias + // 32 cards give 5 bits each + // 16 cards give 4 bits each + // 4 cards give 2 bits each + // Average (32*5 + 16*4 + 4*2) / 52 = 4.46 bits per card without bias + "card": { + "ac": "00000", + "2c": "00001", + "3c": "00010", + "4c": "00011", + "5c": "00100", + "6c": "00101", + "7c": "00110", + "8c": "00111", + "9c": "01000", + "tc": "01001", + "jc": "01010", + "qc": "01011", + "kc": "01100", + "ad": "01101", + "2d": "01110", + "3d": "01111", + "4d": "10000", + "5d": "10001", + "6d": "10010", + "7d": "10011", + "8d": "10100", + "9d": "10101", + "td": "10110", + "jd": "10111", + "qd": "11000", + "kd": "11001", + "ah": "11010", + "2h": "11011", + "3h": "11100", + "4h": "11101", + "5h": "11110", + "6h": "11111", + "7h": "0000", + "8h": "0001", + "9h": "0010", + "th": "0011", + "jh": "0100", + "qh": "0101", + "kh": "0110", + "as": "0111", + "2s": "1000", + "3s": "1001", + "4s": "1010", + "5s": "1011", + "6s": "1100", + "7s": "1101", + "8s": "1110", + "9s": "1111", + "ts": "00", + "js": "01", + "qs": "10", + "ks": "11", + }, + + } + // matchers returns an array of the matched events for each type of entropy. // eg // matchers.binary("010") returns ["0", "1", "0"] @@ -48,48 +180,28 @@ window.Entropy = new (function() { } } - // Convert array of cards from ["ac", "4d", "ks"] - // to numbers between 0 and 51 [0, 16, 51] - function convertCardsToInts(cards) { - var ints = []; - var values = "a23456789tjqk"; - var suits = "cdhs"; - for (var i=0; i -1) { - newParts[i] = base.parts[i]; - newInts[i] = base.ints[i]; + newEvents[i] = base.events[i]; } else { - newParts[i] = "0"; - newInts[i] = 0; + newEvents[i] = "0"; } } base.str = "base 6 (dice)"; - base.ints = newInts; - base.parts = newParts; + base.events = newEvents; base.matcher = matchers.base6; } // Detect empty entropy - if (base.parts.length == 0) { + if (base.events.length == 0) { return { binaryStr: "", cleanStr: "", @@ -97,128 +209,113 @@ window.Entropy = new (function() { base: base, }; } - // 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; - for (var i=base.ints.length-1; i>=0; i--) { - var thisInt = BigInteger.parse(base.ints[i]); - var power = (base.ints.length - 1) - i; - var additionalEntropy = BigInteger.parse(base.asInt).pow(power).multiply(thisInt); - entropyInt = entropyInt.add(additionalEntropy); - } - // Convert entropy to binary - var entropyBin = entropyInt.toString(2); - // If the first integer is small, it must be padded with zeros. - // Otherwise the chance of the first bit being 1 is 100%, which is - // obviously incorrect. - // This is not perfect for non-2^n bases. - var expectedBits = Math.floor(base.parts.length * Math.log2(base.asInt)); - while (entropyBin.length < expectedBits) { - entropyBin = "0" + entropyBin; - } + // Convert entropy events to binary + var entropyBin = base.events.map(function(e) { + return eventBits[base.str][e.toLowerCase()]; + }).join(""); + // Get average bits per event + // which may be adjusted for bias if log2(base) is fractional + var bitsPerEvent = base.bitsPerEvent; // Supply a 'filtered' entropy string for display purposes - var entropyClean = base.parts.join(""); - var entropyHtml = base.parts.join(""); + var entropyClean = base.events.join(""); + var entropyHtml = base.events.join(""); if (base.asInt == 52) { - entropyClean = base.parts.join(" ").toUpperCase(); + entropyClean = base.events.join(" ").toUpperCase(); entropyClean = entropyClean.replace(/C/g, "\u2663"); entropyClean = entropyClean.replace(/D/g, "\u2666"); entropyClean = entropyClean.replace(/H/g, "\u2665"); entropyClean = entropyClean.replace(/S/g, "\u2660"); - entropyHtml = base.parts.join(" ").toUpperCase(); + entropyHtml = base.events.join(" ").toUpperCase(); entropyHtml = entropyHtml.replace(/C/g, "\u2663"); entropyHtml = entropyHtml.replace(/D/g, "\u2666"); entropyHtml = entropyHtml.replace(/H/g, "\u2665"); entropyHtml = entropyHtml.replace(/S/g, "\u2660"); } + // Return the result var e = { binaryStr: entropyBin, cleanStr: entropyClean, cleanHtml: entropyHtml, + bitsPerEvent: bitsPerEvent, base: base, } return e; } - 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, - parts: binaryMatches, + events: binaryMatches, matcher: matchers.binary, asInt: 2, + bitsPerEvent: 1, str: "binary", } } var cardMatches = matchers.card(str); - if (cardMatches.length >= hexMatches.length / 2) { - var ints = convertCardsToInts(cardMatches); + if ((cardMatches.length >= hexMatches.length / 2 && autodetect) || baseStr === "card") { return { ints: ints, - parts: cardMatches, + events: cardMatches, matcher: matchers.card, asInt: 52, + bitsPerEvent: (32*5 + 16*4 + 4*2) / 52, // see cardBits str: "card", } } 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, - parts: diceMatches, + events: diceMatches, matcher: matchers.dice, asInt: 6, + bitsPerEvent: (4*2 + 2*1) / 6, // see diceBits str: "dice", } } 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, - parts: base6Matches, + events: base6Matches, matcher: matchers.base6, asInt: 6, + bitsPerEvent: (4*2 + 2*1) / 6, // see diceBits str: "base 6", } } 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, - parts: base10Matches, + events: base10Matches, matcher: matchers.base10, asInt: 10, + bitsPerEvent: (8*3 + 2*1) / 10, // see b10Bits str: "base 10", } } var ints = hexMatches.map(function(i) { return parseInt(i, 16) }); return { ints: ints, - parts: hexMatches, + events: hexMatches, matcher: matchers.hex, asInt: 16, + bitsPerEvent: 4, str: "hexadecimal", } } - // Polyfill for Math.log2 - // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/log2#Polyfill - Math.log2 = Math.log2 || function(x) { - // The polyfill isn't good enough because of the poor accuracy of - // Math.LOG2E - // log2(8) gave 2.9999999999999996 which when floored causes issues. - // So instead use the BigInteger library to get it right. - return BigInteger.log(x) / BigInteger.log(2); - }; - })();