Card bits per event is shown as the average value

[perso/Immae/Projets/Cryptomonnaies/BIP39.git] / src / js / index.js

diff --git a/src/js/index.js b/src/js/index.js
index dbbd382e406de4ca6e999e3ad62d880e335e8089..12788ab3da7b41620ac6f7ad08a0c2997d5148e8 100644 (file)
--- a/src/js/index.js
+++ b/src/js/index.js
@@ -791,20 +791,21 @@
     }
 
     function showEntropyFeedback(entropy) {
+        var numberOfBits = entropy.binaryStr.length;
         var strength = "extremely weak";
-        if (entropy.binaryStr.length >= 64) {
+        if (numberOfBits >= 64) {
             strength = "very weak";
         }
-        if (entropy.binaryStr.length >= 96) {
+        if (numberOfBits >= 96) {
             strength = "weak";
         }
-        if (entropy.binaryStr.length >= 128) {
+        if (numberOfBits >= 128) {
             strength = "strong";
         }
-        if (entropy.binaryStr.length >= 160) {
+        if (numberOfBits >= 160) {
             strength = "very strong";
         }
-        if (entropy.binaryStr.length >= 192) {
+        if (numberOfBits >= 192) {
             strength = "extremely strong";
         }
         // If time to crack is less than one day, and password is considered
@@ -825,34 +826,20 @@
             console.log("Error detecting entropy strength with zxcvbn:");
             console.log(e);
         }
-        var bitsStr = getNumberOfEntropyBits(entropy);
-        var wordCount = Math.floor(entropy.binaryStr.length / 32) * 3;
         var entropyTypeStr = getEntropyTypeStr(entropy);
+        var wordCount = Math.floor(numberOfBits / 32) * 3;
+        var bitsPerEvent = Math.log2(entropy.base.asInt).toFixed(2);
+        if (entropy.base.asInt == 52) {
+            bitsPerEvent = (4.3381).toFixed(2); // log2(52! / 52)
+        }
         DOM.entropyFiltered.html(entropy.cleanHtml);
         DOM.entropyType.text(entropyTypeStr);
         DOM.entropyStrength.text(strength);
         DOM.entropyEventCount.text(entropy.base.ints.length);
-        DOM.entropyBits.text(bitsStr);
+        DOM.entropyBits.text(numberOfBits);
         DOM.entropyWordCount.text(wordCount);
         DOM.entropyBinary.text(entropy.binaryStr);
-        DOM.entropyBitsPerEvent.text(Math.log2(entropy.base.asInt).toFixed(2));
-    }
-
-    function getNumberOfEntropyBits(entropy) {
-        var bitsStr = entropy.binaryStr.length.toString();
-        // If using cards, assume they are not reused, thus additional entropy
-        // decreases as more cards are used. This means 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
-        if (entropy.base.asInt == 52) {
-            var totalCombos = factorial(52);
-            var remainingCards = 52 - entropy.base.parts.length;
-            var remainingCombos = factorial(remainingCards);
-            var currentCombos = totalCombos.divide(remainingCombos);
-            bitsStr = currentCombos.toString(2).length.toString();
-        }
-        return bitsStr
+        DOM.entropyBitsPerEvent.text(bitsPerEvent);
     }
 
     function getEntropyTypeStr(entropy) {
@@ -865,10 +852,11 @@
             var dupeTracker = {};
             for (var i=0; i<entropy.base.parts.length; i++) {
                 var card = entropy.base.parts[i];
-                if (card in dupeTracker) {
+                var cardUpper = card.toUpperCase();
+                if (cardUpper in dupeTracker) {
                     dupes.push(card);
                 }
-                dupeTracker[card] = true;
+                dupeTracker[cardUpper] = true;
             }
             if (dupes.length > 0) {
                 var dupeWord = "duplicates";
@@ -889,6 +877,26 @@
             if (uniqueCards.length == 52) {
                 cardDetail.unshift("full deck");
             }
+            // Detect missing cards
+            var values = "A23456789TJQK";
+            var suits = "CDHS";
+            var missingCards = [];
+            for (var i=0; i<suits.length; i++) {
+                for (var j=0; j<values.length; j++) {
+                    var card = values[j] + suits[i];
+                    if (!(card in dupeTracker)) {
+                        missingCards.push(card);
+                    }
+                }
+            }
+            // Display missing cards if six or less, ie clearly going for full deck
+            if (missingCards.length > 0 && missingCards.length <= 6) {
+                var msg = missingCards.length + " missing: " + missingCards.slice(0,3).join(" ");
+                if (missingCards.length > 3) {
+                    msg += "...";
+                }
+                cardDetail.push(msg);
+            }
             // Add card details to typeStr
             if (cardDetail.length > 0) {
                 typeStr += " (" + cardDetail.join(", ") + ")";
@@ -897,18 +905,6 @@
         return typeStr;
     }
 
-    // Depends on BigInteger
-    function factorial(n) {
-        if (n == 0) {
-            return 1;
-        }
-        f = BigInteger.ONE;
-        for (var i=1; i<=n; i++) {
-            f = f.multiply(new BigInteger(i));
-        }
-        return f;
-    }
-
     var networks = [
         {
             name: "Bitcoin",