merge server components from staging

lib/metadata.js

@@ -2,23 +2,169 @@ var Meta = module.exports;
 
 var deduplicate = require("./common-util").deduplicateString;
 
-/*  Metadata fields:
+/*  Metadata fields and the commands that can modify them
+
+we assume that these commands can only be performed
+by owners or in some cases pending owners. Thus
+the owners field is guaranteed to exist.
 
     * channel <STRING>
     * validateKey <STRING>
     * owners <ARRAY>
       * ADD_OWNERS
       * RM_OWNERS
+      * RESET_OWNERS
+    * pending_owners <ARRAY>
+      * ADD_PENDING_OWNERS
+      * RM_PENDING_OWNERS
     * expire <NUMBER>
+      * UPDATE_EXPIRATION (NOT_IMPLEMENTED)
+    * restricted <BOOLEAN>
+      * RESTRICT_ACCESS
+    * allowed <ARRAY>
+      * ADD_ALLOWED
+      * RM_ALLOWED
+      * RESET_ALLOWED
+      * ADD_OWNERS
+      * RESET_OWNERS
+    * mailbox <STRING|MAP>
+      * ADD_MAILBOX
+      * RM_MAILBOX
 
 */
 
 var commands = {};
 
-var isValidOwner = function (owner) {
+var isValidPublicKey = function (owner) {
     return typeof(owner) === 'string' && owner.length === 44;
 };
 
+// isValidPublicKey is a better indication of what the above function does
+// I'm preserving this function name in case we ever want to expand its
+// criteria at a later time...
+var isValidOwner = isValidPublicKey;
+
+// ["RESTRICT_ACCESS", [true], 1561623438989]
+// ["RESTRICT_ACCESS", [false], 1561623438989]
+commands.RESTRICT_ACCESS = function (meta, args) {
+    if (!Array.isArray(args) || typeof(args[0]) !== 'boolean') {
+        throw new Error('INVALID_STATE');
+    }
+
+    var bool = args[0];
+
+    // reject the proposed command if there is no change in state
+    if (meta.restricted === bool) { return false; }
+
+    // apply the new state
+    meta.restricted = args[0];
+
+    // if you're disabling access restrictions then you can assume
+    // then there is nothing more to do. Leave the existing list as-is
+    if (!bool) { return true; }
+
+    // you're all set if an allow list already exists
+    if (Array.isArray(meta.allowed)) { return true; }
+
+    // otherwise define it
+    meta.allowed = [];
+
+    return true;
+};
+
+// ["ADD_ALLOWED", ["7eEqelGso3EBr5jHlei6av4r9w2B9XZiGGwA1EgZ-5I=", ...], 1561623438989]
+commands.ADD_ALLOWED = function (meta, args) {
+    if (!Array.isArray(args)) {
+        throw new Error("INVALID_ARGS");
+    }
+
+    var allowed = meta.allowed || [];
+
+    var changed = false;
+    args.forEach(function (arg) {
+        // don't add invalid public keys
+        if (!isValidPublicKey(arg)) { return; }
+        // don't add owners to the allow list
+        if (meta.owners.indexOf(arg) >= 0) { return; }
+        // don't duplicate entries in the allow list
+        if (allowed.indexOf(arg) >= 0) { return; }
+        allowed.push(arg);
+        changed = true;
+    });
+
+    if (changed) {
+        meta.allowed = meta.allowed || allowed;
+    }
+
+    return changed;
+};
+
+// ["RM_ALLOWED", ["7eEqelGso3EBr5jHlei6av4r9w2B9XZiGGwA1EgZ-5I=", ...], 1561623438989]
+commands.RM_ALLOWED = function (meta, args) {
+    if (!Array.isArray(args)) {
+        throw new Error("INVALID_ARGS");
+    }
+
+    // there may not be anything to remove
+    if (!meta.allowed) { return false; }
+
+    var changed = false;
+    args.forEach(function (arg) {
+        var index = meta.allowed.indexOf(arg);
+        if (index < 0) { return; }
+        meta.allowed.splice(index, 1);
+        changed = true;
+    });
+
+    return changed;
+};
+
+var arrayHasChanged = function (A, B) {
+    var changed;
+    A.some(function (a) {
+        if (B.indexOf(a) < 0) { return (changed = true); }
+    });
+    if (changed) { return true; }
+    B.some(function (b) {
+        if (A.indexOf(b) < 0) { return (changed = true); }
+    });
+    return changed;
+};
+
+var filterInPlace = function (A, f) {
+    for (var i = A.length - 1; i >= 0; i--) {
+        if (f(A[i], i, A)) { A.splice(i, 1); }
+    }
+};
+
+// ["RESET_ALLOWED", ["7eEqelGso3EBr5jHlei6av4r9w2B9XZiGGwA1EgZ-5I=", ...], 1561623438989]
+commands.RESET_ALLOWED = function (meta, args) {
+    if (!Array.isArray(args)) { throw new Error("INVALID_ARGS"); }
+
+    var updated = args.filter(function (arg) {
+        // don't allow invalid public keys
+        if (!isValidPublicKey(arg)) { return false; }
+        // don't ever add owners to the allow list
+        if (meta.owners.indexOf(arg)) { return false; }
+        return true;
+    });
+
+    // this is strictly an optimization...
+    // a change in length is a clear indicator of a functional change
+    if (meta.allowed && meta.allowed.length !== updated.length) {
+        meta.allowed = updated;
+        return true;
+    }
+
+    // otherwise we must check that the arrays contain distinct elements
+    // if there is no functional change, then return false
+    if (!arrayHasChanged(meta.allowed, updated)) { return false; }
+
+    // otherwise overwrite the in-memory data and indicate that there was a change
+    meta.allowed = updated;
+    return true;
+};
+
 // ["ADD_OWNERS", ["7eEqelGso3EBr5jHlei6av4r9w2B9XZiGGwA1EgZ-5I="], 1561623438989]
 commands.ADD_OWNERS = function (meta, args) {
     // bail out if args isn't an array
@@ -40,6 +186,13 @@ commands.ADD_OWNERS = function (meta, args) {
         changed = true;
     });
 
+    if (changed && Array.isArray(meta.allowed)) {
+        // make sure owners are not included in the allow list
+        filterInPlace(meta.allowed, function (member) {
+            return meta.owners.indexOf(member) !== -1;
+        });
+    }
+
     return changed;
 };
 
@@ -71,6 +224,10 @@ commands.RM_OWNERS = function (meta, args) {
         changed = true;
     });
 
+    if (meta.owners.length === 0 && meta.restricted) {
+        meta.restricted = false;
+    }
+
     return changed;
 };
 
@@ -141,6 +298,18 @@ commands.RESET_OWNERS = function (meta, args) {
 
     // overwrite the existing owners with the new one
     meta.owners = deduplicate(args.filter(isValidOwner));
+
+    if (Array.isArray(meta.allowed)) {
+        // make sure owners are not included in the allow list
+        filterInPlace(meta.allowed, function (member) {
+            return meta.owners.indexOf(member) !== -1;
+        });
+    }
+
+    if (meta.owners.length === 0 && meta.restricted) {
+        meta.restricted = false;
+    }
+
     return true;
 };
 
@@ -178,6 +347,25 @@ commands.ADD_MAILBOX = function (meta, args) {
     return changed;
 };
 
+commands.RM_MAILBOX = function (meta, args) {
+    if (!Array.isArray(args)) { throw new Error("INVALID_ARGS"); }
+    if (!meta.mailbox || typeof(meta.mailbox) === 'undefined') {
+        return false;
+    }
+    if (typeof(meta.mailbox) === 'string' && args.length === 0) {
+        delete meta.mailbox;
+        return true;
+    }
+
+    var changed = false;
+    args.forEach(function (arg) {
+        if (meta.mailbox[arg] === 'undefined') { return; }
+        delete meta.mailbox[arg];
+        changed = true;
+    });
+    return changed;
+};
+
 commands.UPDATE_EXPIRATION = function () {
     throw new Error("E_NOT_IMPLEMENTED");
 };