field references decoding

app/scripts/mixins/protected-value-ex.js

@@ -2,6 +2,9 @@
 
 var kdbxweb = require('kdbxweb');
 
+const ExpectedFieldRefChars = '{REF:0@I:00000000000000000000000000000000}'.split('');
+const ExpectedFieldRefByteLength = ExpectedFieldRefChars.length;
+
 kdbxweb.ProtectedValue.prototype.isProtected = true;
 
 kdbxweb.ProtectedValue.prototype.forEachChar = function(fn) {
@@ -10,30 +13,42 @@ kdbxweb.ProtectedValue.prototype.forEachChar = function(fn) {
     for (var i = 0, len = value.length; i < len; i++) {
         b = value[i] ^ salt[i];
         if (b < 128) {
-            fn(b);
+            if (fn(b) === false) {
+                return;
+            }
             continue;
         }
         i++; b1 = value[i] ^ salt[i];
         if (i === len) { break; }
         if (b >= 192 && b < 224) {
-            fn(((b & 0x1f) << 6) | (b1 & 0x3f));
+            if (fn(((b & 0x1f) << 6) | (b1 & 0x3f)) === false) {
+                return;
+            }
             continue;
         }
         i++; b2 = value[i] ^ salt[i];
         if (i === len) { break; }
         if (b >= 224 && b < 240) {
-            fn(((b & 0xf) << 12) | ((b1 & 0x3f) << 6) | (b2 & 0x3f));
+            if (fn(((b & 0xf) << 12) | ((b1 & 0x3f) << 6) | (b2 & 0x3f)) === false) {
+                return;
+            }
         }
         i++; b3 = value[i] ^ salt[i];
         if (i === len) { break; }
         if (b >= 240 && b < 248) {
             var c = ((b & 7) << 18) | ((b1 & 0x3f) << 12) | ((b2 & 0x3f) << 6) | (b3 & 0x3f);
             if (c <= 0xffff) {
-                fn(c);
+                if (fn(c) === false) {
+                    return;
+                }
             } else {
                 c ^= 0x10000;
-                fn(0xd800 | (c >> 10));
-                fn(0xdc00 | (c & 0x3ff));
+                if (fn(0xd800 | (c >> 10)) === false) {
+                    return;
+                }
+                if (fn(0xdc00 | (c & 0x3ff)) === false) {
+                    return;
+                }
             }
         }
         // skip error
@@ -98,4 +113,18 @@ kdbxweb.ProtectedValue.prototype.equals = function(other) {
     return true;
 };
 
+kdbxweb.ProtectedValue.prototype.isFieldReference = function() {
+    if (this.byteLength !== ExpectedFieldRefByteLength) {
+        return false;
+    }
+    let ix = 0;
+    this.forEachChar(ch => {
+        let expected = ExpectedFieldRefChars[ix++];
+        if (expected !== '0' && ch !== expected) {
+            return false;
+        }
+    });
+    return true;
+};
+
 module.exports = kdbxweb.ProtectedValue;

app/scripts/models/entry-model.js

@@ -10,9 +10,13 @@ var Backbone = require('backbone'),
 
 var EntryModel = Backbone.Model.extend({
     defaults: {},
-    urlRegex: /^https?:\/\//i,
 
-    builtInFields: ['Title', 'Password', 'Notes', 'URL', 'UserName', 'TOTP Seed', 'TOTP Settings'],
+    urlRegex: /^https?:\/\//i,
+    fieldRefRegex: /^\{REF:([TNPAU])@I:(\w{32})}$/,
+
+    builtInFields: ['Title', 'Password', 'UserName', 'URL', 'Notes', 'TOTP Seed', 'TOTP Settings'],
+    fieldRefFields: ['title', 'password', 'user', 'url', 'notes'],
+    fieldRefIds: { T: 'Title', U: 'UserName', P: 'Password', A: 'URL', N: 'Notes' },
 
     initialize: function() {
     },
@@ -24,7 +28,10 @@ var EntryModel = Backbone.Model.extend({
         if (this.get('uuid') === entry.uuid.id) {
             this._checkUpdatedEntry();
         }
+        // we cannot calculate field references now because database index has not yet been built
+        this.hasFieldRefs = false;
         this._fillByEntry();
+        this.hasFieldRefs = true;
     },
 
     _fillByEntry: function() {
@@ -54,6 +61,9 @@ var EntryModel = Backbone.Model.extend({
         this._buildSearchTags();
         this._buildSearchColor();
         this._buildAutoType();
+        if (this.hasFieldRefs) {
+            this.resolveFieldReferences();
+        }
     },
 
     _checkUpdatedEntry: function() {
@@ -261,6 +271,45 @@ var EntryModel = Backbone.Model.extend({
         return val ? compare(val, search) : false;
     },
 
+    resolveFieldReferences: function() {
+        this.hasFieldRefs = false;
+        this.fieldRefFields.forEach(field => {
+            let fieldValue = this[field];
+            if (!fieldValue) {
+                return;
+            }
+            if (fieldValue.isProtected && fieldValue.isFieldReference()) {
+                fieldValue = fieldValue.getText();
+            }
+            if (typeof fieldValue !== 'string') {
+                return;
+            }
+            let match = fieldValue.match(this.fieldRefRegex);
+            if (!match) {
+                return;
+            }
+            this.hasFieldRefs = true;
+            let value = this._getReferenceValue(match[1], match[2]);
+            if (!value) {
+                return;
+            }
+            this[field] = value;
+        });
+    },
+
+    _getReferenceValue: function(fieldRefId, idStr) {
+        let id = new Uint8Array(16);
+        for (let i = 0; i < 16; i++) {
+            id[i] = parseInt(idStr.substr(i * 2, 2), 16);
+        }
+        let uuid = new kdbxweb.KdbxUuid(id);
+        let entry = this.file.getEntry(this.file.subId(uuid.id));
+        if (!entry) {
+            return undefined;
+        }
+        return entry.entry.fields[this.fieldRefIds[fieldRefId]];
+    },
+
     setColor: function(color) {
         this._entryModified();
         this.entry.bgColor = Color.getKnownBgColor(color);

app/scripts/models/file-model.js

@@ -156,6 +156,7 @@ var FileModel = Backbone.Model.extend({
             groups.add(groupModel);
         }, this);
         this.buildObjectMap();
+        this.resolveFieldReferences();
     },
 
     subId: function(id) {
@@ -175,6 +176,13 @@ var FileModel = Backbone.Model.extend({
         this.groupMap = groupMap;
     },
 
+    resolveFieldReferences: function() {
+        let entryMap = this.entryMap;
+        Object.keys(entryMap).forEach(e => {
+            entryMap[e].resolveFieldReferences();
+        });
+    },
+
     reload: function() {
         this.buildObjectMap();
         this.readModel();

release-notes.md

@@ -13,6 +13,7 @@ Audit, generator presets, auto-type and ui improvements
 `+` save displayed table columns  
 `+` confirmation in password change dialog  
 `+` inline generator keyboard management  
+`+` field references decoding  
 `-` fix app redraw in background  
 `-` fix idle timer on computer sleep