Kernel: use explicit mapping for namespaces rather than hash (#410)

Fixes #337.

I've opted to keep the "app identifier" nomenclature rather than "app name" due to it breaking less external interfaces (e.g. events). A name and an identifier are pretty similar anyway, we just shouldn't have both concepts.

contracts/apps/AppProxyBase.sol

@@ -2,7 +2,7 @@ pragma solidity 0.4.24;
 
 import "./AppStorage.sol";
 import "../common/DepositableDelegateProxy.sol";
-import "../kernel/KernelStorage.sol";
+import "../kernel/KernelConstants.sol";
 import "../kernel/IKernel.sol";
 
 
@@ -33,6 +33,6 @@ contract AppProxyBase is AppStorage, DepositableDelegateProxy, KernelConstants {
     }
 
     function getAppBase(bytes32 _appId) internal view returns (address) {
-        return kernel().getApp(keccak256(abi.encodePacked(APP_BASES_NAMESPACE, _appId)));
+        return kernel().getApp(APP_BASES_NAMESPACE, _appId);
     }
 }

contracts/evmscript/EVMScriptRunner.sol

@@ -8,10 +8,11 @@ import "./IEVMScriptExecutor.sol";
 import "./IEVMScriptRegistry.sol";
 
 import "../apps/AppStorage.sol";
+import "../kernel/KernelConstants.sol";
 import "../common/Initializable.sol";
 
 
-contract EVMScriptRunner is AppStorage, Initializable, EVMScriptRegistryConstants {
+contract EVMScriptRunner is AppStorage, Initializable, EVMScriptRegistryConstants, KernelConstants {
     event ScriptResult(address indexed executor, bytes script, bytes input, bytes returnData);
 
     function getExecutor(bytes _script) public view returns (IEVMScriptExecutor) {
@@ -40,7 +41,7 @@ contract EVMScriptRunner is AppStorage, Initializable, EVMScriptRegistryConstant
     }
 
     function getExecutorRegistry() internal view returns (IEVMScriptRegistry) {
-        address registryAddr = kernel().getApp(EVMSCRIPT_REGISTRY_APP);
+        address registryAddr = kernel().getApp(APP_ADDR_NAMESPACE, EVMSCRIPT_REGISTRY_APP_ID);
         return IEVMScriptRegistry(registryAddr);
     }
 

contracts/evmscript/IEVMScriptRegistry.sol

@@ -9,13 +9,9 @@ import "./IEVMScriptExecutor.sol";
 
 contract EVMScriptRegistryConstants {
     /* Hardcoded constants to save gas
-    bytes32 constant public APP_ADDR_NAMESPACE = keccak256("app");
-
     bytes32 constant public EVMSCRIPT_REGISTRY_APP_ID = apmNamehash("evmreg");
-    bytes32 constant public EVMSCRIPT_REGISTRY_APP = keccak256(APP_ADDR_NAMESPACE, EVMSCRIPT_REGISTRY_APP_ID);
     */
     bytes32 constant public EVMSCRIPT_REGISTRY_APP_ID = 0xddbcfd564f642ab5627cf68b9b7d374fb4f8a36e941a75d89c87998cef03bd61;
-    bytes32 constant public EVMSCRIPT_REGISTRY_APP = 0x34f01c17e9be6ddbf2c61f37b5b1fb9f1a090a975006581ad19bda1c4d382871;
 }
 
 

contracts/kernel/IKernel.sol

@@ -10,11 +10,11 @@ import "../common/IVaultRecoverable.sol";
 
 // This should be an interface, but interfaces can't inherit yet :(
 contract IKernel is IVaultRecoverable {
-    event SetApp(bytes32 indexed namespace, bytes32 indexed name, bytes32 indexed id, address app);
+    event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
 
     function acl() public view returns (IACL);
     function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
 
-    function setApp(bytes32 namespace, bytes32 name, address app) public returns (bytes32 id);
-    function getApp(bytes32 id) public view returns (address);
+    function setApp(bytes32 namespace, bytes32 appId, address app) public;
+    function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
 }

contracts/kernel/Kernel.sol

@@ -14,9 +14,9 @@ import "../factory/AppProxyFactory.sol";
 contract Kernel is IKernel, KernelStorage, Petrifiable, IsContract, VaultRecoverable, AppProxyFactory, ACLSyntaxSugar {
     // Hardcode constant to save gas
     //bytes32 constant public APP_MANAGER_ROLE = keccak256("APP_MANAGER_ROLE");
-    //bytes32 constant public DEFAULT_VAULT_ID = keccak256(APP_ADDR_NAMESPACE, apmNamehash("vault"));
+    //bytes32 constant public DEFAULT_VAULT_APP_ID = apmNamehash("vault");
     bytes32 constant public APP_MANAGER_ROLE = 0xb6d92708f3d4817afc106147d969e229ced5c46e65e0a5002a0d391287762bd0;
-    bytes32 constant public DEFAULT_VAULT_ID = 0x4214e5fd6d0170d69ea641b5614f5093ebecc9928af51e95685c87617489800e;
+    bytes32 constant public DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
 
     /**
     * @dev Constructor that allows the deployer to choose if the base instance should be petrified immediately.
@@ -37,138 +37,142 @@ contract Kernel is IKernel, KernelStorage, Petrifiable, IsContract, VaultRecover
     function initialize(IACL _baseAcl, address _permissionsCreator) public onlyInit {
         initialized();
 
-        IACL acl = IACL(newAppProxy(this, ACL_APP_ID));
-
+        // Set ACL base
         _setApp(APP_BASES_NAMESPACE, ACL_APP_ID, _baseAcl);
-        _setApp(APP_ADDR_NAMESPACE, ACL_APP_ID, acl);
 
+        // Create ACL instance and attach it as the default ACL app
+        IACL acl = IACL(newAppProxy(this, ACL_APP_ID));
         acl.initialize(_permissionsCreator);
+        _setApp(APP_ADDR_NAMESPACE, ACL_APP_ID, acl);
 
-        recoveryVaultId = DEFAULT_VAULT_ID;
+        recoveryVaultAppId = DEFAULT_VAULT_APP_ID;
     }
 
     /**
     * @dev Create a new instance of an app linked to this kernel
-    * @param _name Name of the app
+    * @param _appId Identifier for app
     * @param _appBase Address of the app's base implementation
     * @return AppProxy instance
     */
-    function newAppInstance(bytes32 _name, address _appBase)
+    function newAppInstance(bytes32 _appId, address _appBase)
         public
-        auth(APP_MANAGER_ROLE, arr(APP_BASES_NAMESPACE, _name))
+        auth(APP_MANAGER_ROLE, arr(APP_BASES_NAMESPACE, _appId))
         returns (ERCProxy appProxy)
     {
-        return newAppInstance(_name, _appBase, false);
+        return newAppInstance(_appId, _appBase, false);
     }
 
     /**
     * @dev Create a new instance of an app linked to this kernel and set its base
     *      implementation if it was not already set
-    * @param _name Name of the app
+    * @param _appId Identifier for app
     * @param _appBase Address of the app's base implementation
     * @param _setDefault Whether the app proxy app is the default one.
     *        Useful when the Kernel needs to know of an instance of a particular app,
     *        like Vault for escape hatch mechanism.
     * @return AppProxy instance
     */
-    function newAppInstance(bytes32 _name, address _appBase, bool _setDefault)
+    function newAppInstance(bytes32 _appId, address _appBase, bool _setDefault)
         public
-        auth(APP_MANAGER_ROLE, arr(APP_BASES_NAMESPACE, _name))
+        auth(APP_MANAGER_ROLE, arr(APP_BASES_NAMESPACE, _appId))
         returns (ERCProxy appProxy)
     {
-        _setAppIfNew(APP_BASES_NAMESPACE, _name, _appBase);
-        appProxy = newAppProxy(this, _name);
+        _setAppIfNew(APP_BASES_NAMESPACE, _appId, _appBase);
+        appProxy = newAppProxy(this, _appId);
         // By calling setApp directly and not the internal functions, we make sure the params are checked
         // and it will only succeed if sender has permissions to set something to the namespace.
         if (_setDefault) {
-            setApp(APP_ADDR_NAMESPACE, _name, appProxy);
+            setApp(APP_ADDR_NAMESPACE, _appId, appProxy);
         }
     }
 
     /**
     * @dev Create a new pinned instance of an app linked to this kernel
-    * @param _name Name of the app
+    * @param _appId Identifier for app
     * @param _appBase Address of the app's base implementation
     * @return AppProxy instance
     */
-    function newPinnedAppInstance(bytes32 _name, address _appBase)
+    function newPinnedAppInstance(bytes32 _appId, address _appBase)
         public
-        auth(APP_MANAGER_ROLE, arr(APP_BASES_NAMESPACE, _name))
+        auth(APP_MANAGER_ROLE, arr(APP_BASES_NAMESPACE, _appId))
         returns (ERCProxy appProxy)
     {
-        return newPinnedAppInstance(_name, _appBase, false);
+        return newPinnedAppInstance(_appId, _appBase, false);
     }
 
     /**
     * @dev Create a new pinned instance of an app linked to this kernel and set
     *      its base implementation if it was not already set
-    * @param _name Name of the app
+    * @param _appId Identifier for app
     * @param _appBase Address of the app's base implementation
     * @param _setDefault Whether the app proxy app is the default one.
     *        Useful when the Kernel needs to know of an instance of a particular app,
     *        like Vault for escape hatch mechanism.
     * @return AppProxy instance
     */
-    function newPinnedAppInstance(bytes32 _name, address _appBase, bool _setDefault)
+    function newPinnedAppInstance(bytes32 _appId, address _appBase, bool _setDefault)
         public
-        auth(APP_MANAGER_ROLE, arr(APP_BASES_NAMESPACE, _name))
+        auth(APP_MANAGER_ROLE, arr(APP_BASES_NAMESPACE, _appId))
         returns (ERCProxy appProxy)
     {
-        _setAppIfNew(APP_BASES_NAMESPACE, _name, _appBase);
-        appProxy = newAppProxyPinned(this, _name);
+        _setAppIfNew(APP_BASES_NAMESPACE, _appId, _appBase);
+        appProxy = newAppProxyPinned(this, _appId);
         // By calling setApp directly and not the internal functions, we make sure the params are checked
         // and it will only succeed if sender has permissions to set something to the namespace.
         if (_setDefault) {
-            setApp(APP_ADDR_NAMESPACE, _name, appProxy);
+            setApp(APP_ADDR_NAMESPACE, _appId, appProxy);
         }
     }
 
     /**
     * @dev Set the resolving address of an app instance or base implementation
     * @param _namespace App namespace to use
-    * @param _name Name of the app
-    * @param _app Address of the app
+    * @param _appId Identifier for app
+    * @param _app Address of the app instance or base implementation
     * @return ID of app
     */
-    function setApp(bytes32 _namespace, bytes32 _name, address _app)
+    function setApp(bytes32 _namespace, bytes32 _appId, address _app)
         public
-        auth(APP_MANAGER_ROLE, arr(_namespace, _name))
-        returns (bytes32 id)
+        auth(APP_MANAGER_ROLE, arr(_namespace, _appId))
     {
-        return _setApp(_namespace, _name, _app);
+        _setApp(_namespace, _appId, _app);
     }
 
     /**
     * @dev Set the default vault id for the escape hatch mechanism
-    * @param _name Name of the app
+    * @param _recoveryVaultAppId Identifier of the recovery vault app
     */
-    function setRecoveryVaultId(bytes32 _name) public auth(APP_MANAGER_ROLE, arr(APP_ADDR_NAMESPACE, _name)) {
-        recoveryVaultId = keccak256(abi.encodePacked(APP_ADDR_NAMESPACE, _name));
+    function setRecoveryVaultAppId(bytes32 _recoveryVaultAppId)
+        public
+        auth(APP_MANAGER_ROLE, arr(APP_ADDR_NAMESPACE, _recoveryVaultAppId))
+    {
+        recoveryVaultAppId = _recoveryVaultAppId;
     }
 
     /**
     * @dev Get the address of an app instance or base implementation
-    * @param _id App identifier
+    * @param _namespace App namespace to use
+    * @param _appId Identifier for app
     * @return Address of the app
     */
-    function getApp(bytes32 _id) public view returns (address) {
-        return apps[_id];
+    function getApp(bytes32 _namespace, bytes32 _appId) public view returns (address) {
+        return apps[_namespace][_appId];
     }
 
     /**
     * @dev Get the address of the recovery Vault instance (to recover funds)
     * @return Address of the Vault
     */
     function getRecoveryVault() public view returns (address) {
-        return apps[recoveryVaultId];
+        return apps[APP_ADDR_NAMESPACE][recoveryVaultAppId];
     }
 
     /**
     * @dev Get the installed ACL app
     * @return ACL app
     */
     function acl() public view returns (IACL) {
-        return IACL(getApp(ACL_APP));
+        return IACL(getApp(APP_ADDR_NAMESPACE, ACL_APP_ID));
     }
 
     /**
@@ -186,24 +190,19 @@ contract Kernel is IKernel, KernelStorage, Petrifiable, IsContract, VaultRecover
             defaultAcl.hasPermission(_who, _where, _what, _how);
     }
 
-    function _setApp(bytes32 _namespace, bytes32 _name, address _app) internal returns (bytes32 id) {
+    function _setApp(bytes32 _namespace, bytes32 _appId, address _app) internal {
         require(isContract(_app));
-        id = keccak256(abi.encodePacked(_namespace, _name));
-        apps[id] = _app;
-        emit SetApp(_namespace, _name, id, _app);
+        apps[_namespace][_appId] = _app;
+        emit SetApp(_namespace, _appId, _app);
     }
 
-    function _setAppIfNew(bytes32 _namespace, bytes32 _name, address _app) internal returns (bytes32 id) {
-        require(isContract(_app));
-
-        id = keccak256(abi.encodePacked(_namespace, _name));
-
-        address app = getApp(id);
+    function _setAppIfNew(bytes32 _namespace, bytes32 _appId, address _app) internal {
+        address app = getApp(_namespace, _appId);
         if (app != address(0)) {
+            // The only way to set an app is if it passes the isContract check, so no need to check it again
             require(app == _app);
         } else {
-            apps[id] = _app;
-            emit SetApp(_namespace, _name, id, _app);
+            _setApp(_namespace, _appId, _app);
         }
     }
 

contracts/kernel/KernelConstants.sol

@@ -0,0 +1,19 @@
+pragma solidity 0.4.24;
+
+
+contract KernelConstants {
+    /*
+    bytes32 constant public CORE_NAMESPACE = keccak256("core");
+    bytes32 constant public APP_BASES_NAMESPACE = keccak256("base");
+    bytes32 constant public APP_ADDR_NAMESPACE = keccak256("app");
+
+    bytes32 constant public KERNEL_APP_ID = apmNamehash("kernel");
+    bytes32 constant public ACL_APP_ID = apmNamehash("acl");
+    */
+    bytes32 constant public CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
+    bytes32 constant public APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
+    bytes32 constant public APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
+
+    bytes32 constant public KERNEL_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
+    bytes32 constant public ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
+}

contracts/kernel/KernelProxy.sol

@@ -14,7 +14,7 @@ contract KernelProxy is KernelStorage, IsContract, DepositableDelegateProxy {
     */
     constructor(IKernel _kernelImpl) public {
         require(isContract(address(_kernelImpl)));
-        apps[KERNEL_APP] = _kernelImpl;
+        apps[CORE_NAMESPACE][KERNEL_APP_ID] = _kernelImpl;
     }
 
     /**
@@ -28,6 +28,6 @@ contract KernelProxy is KernelStorage, IsContract, DepositableDelegateProxy {
     * @dev ERC897, the address the proxy would delegate calls to
     */
     function implementation() public view returns (address) {
-        return apps[KERNEL_APP];
+        return apps[CORE_NAMESPACE][KERNEL_APP_ID];
     }
 }

contracts/kernel/KernelStorage.sol

@@ -1,32 +1,9 @@
 pragma solidity 0.4.24;
 
-
-contract KernelConstants {
-    /*
-    bytes32 constant public CORE_NAMESPACE = keccak256("core");
-    bytes32 constant public APP_BASES_NAMESPACE = keccak256("base");
-    bytes32 constant public APP_ADDR_NAMESPACE = keccak256("app");
-
-    bytes32 constant public KERNEL_APP_ID = apmNamehash("kernel");
-    bytes32 constant public KERNEL_APP = keccak256(CORE_NAMESPACE, KERNEL_APP_ID);
-
-    bytes32 constant public ACL_APP_ID = apmNamehash("acl");
-    bytes32 constant public ACL_APP = keccak256(APP_ADDR_NAMESPACE, ACL_APP_ID);
-    */
-    bytes32 constant public CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
-    bytes32 constant public APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
-    bytes32 constant public APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
-
-    bytes32 constant public KERNEL_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
-    bytes32 constant public KERNEL_APP = 0x2b7d19d0575c228f8d9326801e14149d284dc5bb7b1541c5ad712ae4b2fcaadb;
-
-    bytes32 constant public ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
-    bytes32 constant public ACL_APP = 0x4b8e03a458a6ccec5d9077c2490964c1333dd3c72e2db408d7d9a7a36ef5c41a;
-
-}
+import "./KernelConstants.sol";
 
 
 contract KernelStorage is KernelConstants {
-    mapping (bytes32 => address) public apps;
-    bytes32 public recoveryVaultId;
+    mapping (bytes32 => mapping (bytes32 => address)) public apps;
+    bytes32 public recoveryVaultAppId;
 }

contracts/test/mocks/KeccakConstants.sol

@@ -12,18 +12,11 @@ contract KeccakConstants is APMNamehash {
     bytes32 constant public APP_ADDR_NAMESPACE = keccak256(abi.encodePacked("app"));
 
     bytes32 constant public KERNEL_APP_ID = keccak256(abi.encodePacked(APM_NODE, keccak256("kernel")));
-    bytes32 constant public KERNEL_APP = keccak256(abi.encodePacked(CORE_NAMESPACE, KERNEL_APP_ID));
-
     bytes32 constant public ACL_APP_ID = keccak256(abi.encodePacked(APM_NODE, keccak256("acl")));
-    bytes32 constant public ACL_APP = keccak256(abi.encodePacked(APP_ADDR_NAMESPACE, ACL_APP_ID));
 
     bytes32 constant public APP_MANAGER_ROLE = keccak256(abi.encodePacked("APP_MANAGER_ROLE"));
 
-    bytes32 constant public DEFAULT_VAULT_ID = keccak256(
-        abi.encodePacked(
-            APP_ADDR_NAMESPACE, keccak256(abi.encodePacked(APM_NODE, keccak256("vault")))
-        )
-    );
+    bytes32 constant public DEFAULT_VAULT_APP_ID = keccak256(abi.encodePacked(APM_NODE, keccak256("vault")));
 
     // ENS
     bytes32 constant public ENS_ROOT = bytes32(0);
@@ -46,7 +39,6 @@ contract KeccakConstants is APMNamehash {
 
     // EVMScriptRegistry
     bytes32 constant public EVMSCRIPT_REGISTRY_APP_ID = keccak256(abi.encodePacked(APM_NODE, keccak256("evmreg")));
-    bytes32 constant public EVMSCRIPT_REGISTRY_APP = keccak256(abi.encodePacked(APP_ADDR_NAMESPACE, EVMSCRIPT_REGISTRY_APP_ID));
     bytes32 constant public REGISTRY_ADD_EXECUTOR_ROLE = keccak256("REGISTRY_ADD_EXECUTOR_ROLE");
     bytes32 constant public REGISTRY_MANAGER_ROLE = keccak256(abi.encodePacked("REGISTRY_MANAGER_ROLE"));