recovery alpha + ens based recoverer

contracts/deploy/AbstractRecoverer.sol

@@ -9,16 +9,26 @@ import "./BasicSystemStorage.sol";
  * @dev Abstract recoverer contract that should be crafted to alter `address system` storage 
  * in delegated logic contracts.
  */
-contract AnstractRecoverer is BasicSystemStorage {
+contract AbstractRecoverer is BasicSystemStorage {
     
      /**
      * @dev will be callable in emergency state of RecorverableSystem
      */
     function recoverSystem(address newSystem) public {
         require(msg.sender == consensusContract());
+        require(isOk(newSystem));
         system = newSystem;
     }
     
+    /**
+     * @dev checks if `_a` contains code
+     */
+    function isOk(address _a) internal constant returns(bool r) {
+        assembly{
+            r := gt(extcodesize(_a), 0)
+        }
+    }
+    
      /**
      * @dev returns the consesus contract, can be a multisig or other DAO
      * should be implemented by a child contract

contracts/deploy/BasicSystemStorage.sol

@@ -8,9 +8,7 @@ pragma solidity ^0.4.17;
  * avoid overwriting wrong storage pointers
  */
 contract BasicSystemStorage {    
-    /// protected zone start (RecorverableSystem vars)
-    address system;
-    address recover;
-    address watchdog;
-    /// protected zone end
+    address public system;
+    address public recover;
+    address public watchdog;
 }

contracts/deploy/DelegatedCall.sol

@@ -11,14 +11,14 @@ contract DelegatedCall {
      * @dev delegates the call of this function
      */
     modifier delegated {
-        require(_target().delegatecall(msg.data)); //require successfull delegate call to remote `_target()`
+        //require successfull delegate call to remote `_target()`
+        require(_target().delegatecall(msg.data));
         assembly {
             let outSize := returndatasize 
             let outDataPtr := mload(0x40) //load memory
             returndatacopy(outDataPtr, 0, outSize) //copy last return into pointer
             return(outDataPtr, outSize) 
         }
-        assert(false); //should never reach here
         _; //never will execute local logic
     }
 

contracts/deploy/ENSRecoverer.sol

@@ -0,0 +1,24 @@
+pragma solidity ^0.4.17;
+
+import "./AbstractRecoverer.sol";
+import "../ens/ENS.sol";
+
+
+/**
+* @title ENSRecoverer
+* @author Ricardo Guilherme Schmidt (Status Research & Development GmbH) 
+* @dev Common abstract recoverer resolved from ens.
+*/
+contract ENSRecoverer is AbstractRecoverer {
+    /**
+    * @dev resolves consensusContract from ens.
+    */
+    function consensusContract() public constant returns(address) {
+        bytes32 node = ensNode();
+        return ensRoot().resolver(node).addr(node);
+    }
+
+    function ensNode() public constant returns(bytes32);
+    function ensRoot() public constant returns(ENS);
+
+}

contracts/deploy/KillableModel.sol

@@ -17,14 +17,6 @@ contract KillableModel is BasicSystemStorage {
         watchdog = _watchdog;
     }
 
-    function changeWatchdog(address newWatchDog) public {
-        require(msg.sender == watchdog);
-        watchdog = newWatchDog;
-    }
-
-    /**
-     * @dev Should be only possible to call this at Model. Never set watchdog var at instances.
-     */
     function emergencyStop() public {
         require(msg.sender == watchdog);
         selfdestruct(watchdog);

contracts/deploy/RecoverableSystem.sol

@@ -11,6 +11,11 @@ import "./DelegatedCall.sol";
  */
     contract RecoverableSystem is BasicSystemStorage, DelegatedCall {
 
+    /**
+     * @dev Requires at least valid _recoverer, that can elect the first system.
+     * @param _system the first system
+     * @param _recover the recoverer contract 
+     */
     function RecoverableSystem(address _system, address _recover) public {
         require(isOk(_recover));
         system = _system;
@@ -20,12 +25,12 @@ contract RecoverableSystem is BasicSystemStorage, DelegatedCall {
     /**
      * @dev delegatecall everything (but declared functions) to `_target()`
      */
-    function () public delegated {
+    function () external payable delegated {
         //all goes to system (or recover)
     }
 
     /**
-     * @dev checks if system contains code
+     * @dev checks if system is not in recovery mode
      */
     function isOk() public constant returns(bool a) {
         return isOk(system);

contracts/ens/ENS.sol

@@ -0,0 +1,14 @@
+pragma solidity ^0.4.17;
+
+import "./Resolver.sol";
+
+
+contract ENS {
+    function owner(bytes32 node) public constant returns (address);
+    function resolver(bytes32 node) public constant returns (Resolver);
+    function ttl(bytes32 node) public constant returns (uint64);
+    function setOwner(bytes32 node, address owner) public;
+    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) public;
+    function setResolver(bytes32 node, address resolver) public;
+    function setTTL(bytes32 node, uint64 ttl) public;
+}

contracts/ens/Resolver.sol

@@ -0,0 +1,5 @@
+pragma solidity ^0.4.17;
+
+contract Resolver {
+    function addr(bytes32 node) public constant returns (address);
+}