Validate prefix on external controller additions (#22)

Validate prefix on external controller additions


---------

Authored-by: Robert Leonard 
Reviewed-by: Martin Riedel

src/DidRegistry.sol

@@ -237,6 +237,7 @@ contract DIDRegistry is IDidRegistry, Initializable, UUPSUpgradeable, OwnableUpg
     }
 
      function addExternalController(address didIdentifier, string calldata controller) onlyNonGenerativeDid(didIdentifier) onlyAuthorizedKeys(didIdentifier) public  {
+        _doesExternalControllerHaveCorrectPrefix(controller);
         require(_doesExternalControllerExist(didIdentifier,controller) == -1, "External controller already exist");
         didStates[didIdentifier].externalControllers.push(controller);
 
@@ -347,6 +348,16 @@ contract DIDRegistry is IDidRegistry, Initializable, UUPSUpgradeable, OwnableUpg
         return false;
     }
 
+    function _doesExternalControllerHaveCorrectPrefix(string memory str) internal pure {
+        bytes memory correctPrefix = bytes("did:");
+        bytes memory bytesString = bytes(str);
+
+        // Get first 4 charecters in string
+        for(uint i = 0; i < 4; i++) {
+            require(correctPrefix[i] == bytesString[i], "Invalid prefix for external controller. External controls must start with did:");
+        }
+    }
+
     function _stringCompare(string memory str1, string memory str2) internal pure returns (bool) {
         if (bytes(str1).length != bytes(str2).length) {
             return false;

test/DidRegistryControllerTest.sol

@@ -35,7 +35,7 @@ contract DidRegistryControllerTest is DidRegistryTest {
 
     function test_should_add_new_external_controller() public {
         address user = vm.addr(1);
-        string memory newController = "testExternalController";
+        string memory newController = "did:testExternalController";
 
         vm.startPrank(user); // Make transactions using users EOA
         didRegistry.initializeDidState(user);
@@ -49,7 +49,7 @@ contract DidRegistryControllerTest is DidRegistryTest {
 
     function test_should_remove_new_external_controller() public {
         address user = vm.addr(1);
-        string memory newController = "testExternalController";
+        string memory newController = "did:testExternalController";
 
         vm.startPrank(user); // Make transactions using users EOA
         didRegistry.initializeDidState(user);
@@ -62,6 +62,17 @@ contract DidRegistryControllerTest is DidRegistryTest {
         assertEq(controllers.length, 0);
     }
 
+    function test_revert_should_fail_to_add_new_external_controller() public {
+        address user = vm.addr(1);
+        string memory newController = "testExternalController";
+
+        vm.startPrank(user); // Make transactions using users EOA
+        didRegistry.initializeDidState(user);
+
+        vm.expectRevert("Invalid prefix for external controller. External controls must start with did:");
+        didRegistry.addExternalController(user, newController);
+    }
+
     function test_revert_should_fail_to_add_duplicate_native_controller() public {
         address user = vm.addr(1);
         address newController = vm.addr(2);
@@ -101,7 +112,7 @@ contract DidRegistryControllerTest is DidRegistryTest {
 
     function test_revert_should_fail_to_add_duplicate_external_controller() public {
         address user = vm.addr(1);
-        string memory newController = "testExternalController";
+        string memory newController = "did:testExternalController";
 
         vm.startPrank(user); // Make transactions using users EOA
         didRegistry.initializeDidState(user);