Adding support for ERC 1271

contracts/ERC1271Sample.sol

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: CC0-1.0
+pragma solidity ^0.5.16;
+
+import "./IERC1271.sol";
+
+// libraries
+import "@openzeppelin/contracts/ownership/Ownable.sol";
+
+/**
+ * @notice ERC-1271: Standard Signature Validation Method for Contracts
+ */
+contract ERC1271Sample is ERC1271, Ownable {
+
+  // bytes4(keccak256("isValidSignature(bytes32,bytes)")
+  bytes4 constant internal MAGICVALUE = 0x1626ba7e;
+
+  // To store the Data Hash => Singature Hash
+  mapping(bytes32 => bytes32) public signatures;
+
+  /**
+   * @dev Should return whether the signature provided is valid for the provided data
+   * @param _hash Arbitrary length data signed on the behalf of address(this)
+   * @param _signature Signature byte array associated with _hash
+   *
+   * MUST return the bytes4 magic value 0x1626ba7e when function passes.
+   * MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for solc > 0.5)
+   * MUST allow external calls
+   */ 
+  function isValidSignature(
+    bytes32 _hash, 
+    bytes memory _signature)
+    public
+    view 
+    returns (bytes4 magicValue) {
+      if(signatures[_hash] == keccak256(_signature))
+        return MAGICVALUE;
+      return 0;
+  }
+
+  function addSignature(
+    bytes32 _hash, 
+    bytes memory _signature)
+    public 
+    onlyOwner {
+      signatures[_hash] = keccak256(_signature);
+  }
+
+  function addSignature(
+    bytes32 _hash, 
+    bytes32 _signatureHash)
+    public 
+    onlyOwner {
+      signatures[_hash] = _signatureHash;
+  }
+}

contracts/EthereumDIDRegistry.sol

@@ -1,6 +1,13 @@
-pragma solidity ^0.4.4;
+pragma solidity ^0.5.16;
+
+import "./IERC1271.sol";
+
+// libraries
+import "@openzeppelin/contracts/cryptography/ECDSA.sol";
 
 contract EthereumDIDRegistry {
+
+  bytes4 internal constant _ERC1271_MAGICVALUE = 0x1626ba7e;
 
   mapping(address => address) public owners;
   mapping(address => mapping(bytes32 => mapping(address => uint))) public delegates;
@@ -36,7 +43,7 @@ contract EthereumDIDRegistry {
 
   function identityOwner(address identity) public view returns(address) {
      address owner = owners[identity];
-     if (owner != 0x0) {
+     if (owner != address(0x0)) {
        return owner;
      }
      return identity;
@@ -49,8 +56,41 @@ contract EthereumDIDRegistry {
     return signer;
   }
 
+    /**
+     * @notice Checks if an identity's owner had provided a valid `_signature` for `_hash`.
+     * If the identity's owner is a smart contract, the 'isValidSignature' will be called accourding to ERC1271 interface.
+     *
+     * @param _hash hash of the data signed//Arbitrary length data signed on the behalf of `identity`
+     * @param _signature identity's signature(s) of the data
+     */
+    function checkSignature(
+        address identity,
+        bytes32 _hash,
+        bytes memory _signature
+    ) internal returns (address) {
+        address owner = identityOwner(identity);
+        bool isContract;
+        // solium-disable-next-line security/no-inline-assembly
+        assembly {
+            isContract := gt(extcodesize(owner), 0)
+        }
+        if (isContract) {
+            require(
+                _ERC1271_MAGICVALUE ==
+                    ERC1271(owner).isValidSignature(_hash, _signature)
+            );
+            nonce[owner]++;
+            return owner;
+        } else {
+            address signer = ECDSA.recover(_hash, _signature);
+            require(signer == identityOwner(identity));
+            nonce[signer]++;
+            return signer;
+        }
+    }
+
   function validDelegate(address identity, bytes32 delegateType, address delegate) public view returns(bool) {
-    uint validity = delegates[identity][keccak256(delegateType)][delegate];
+    uint validity = delegates[identity][keccak256(abi.encodePacked(delegateType))][delegate];
     return (validity > now);
   }
 
@@ -65,12 +105,17 @@ contract EthereumDIDRegistry {
   }
 
   function changeOwnerSigned(address identity, uint8 sigV, bytes32 sigR, bytes32 sigS, address newOwner) public {
-    bytes32 hash = keccak256(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "changeOwner", newOwner);
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "changeOwner", newOwner));
     changeOwner(identity, checkSignature(identity, sigV, sigR, sigS, hash), newOwner);
   }
 
+  function changeOwnerSigned(address identity, bytes memory signature, address newOwner) public {
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "changeOwner", newOwner));
+    changeOwner(identity, checkSignature(identity, hash, signature), newOwner);
+  }
+
   function addDelegate(address identity, address actor, bytes32 delegateType, address delegate, uint validity) internal onlyOwner(identity, actor) {
-    delegates[identity][keccak256(delegateType)][delegate] = now + validity;
+    delegates[identity][keccak256(abi.encodePacked(delegateType))][delegate] = now + validity;
     emit DIDDelegateChanged(identity, delegateType, delegate, now + validity, changed[identity]);
     changed[identity] = block.number;
   }
@@ -80,12 +125,17 @@ contract EthereumDIDRegistry {
   }
 
   function addDelegateSigned(address identity, uint8 sigV, bytes32 sigR, bytes32 sigS, bytes32 delegateType, address delegate, uint validity) public {
-    bytes32 hash = keccak256(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "addDelegate", delegateType, delegate, validity);
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "addDelegate", delegateType, delegate, validity));
     addDelegate(identity, checkSignature(identity, sigV, sigR, sigS, hash), delegateType, delegate, validity);
   }
 
+  function addDelegateSigned(address identity, bytes memory signature, bytes32 delegateType, address delegate, uint validity) public {
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "addDelegate", delegateType, delegate, validity));
+    addDelegate(identity, checkSignature(identity, hash, signature), delegateType, delegate, validity);
+  }
+
   function revokeDelegate(address identity, address actor, bytes32 delegateType, address delegate) internal onlyOwner(identity, actor) {
-    delegates[identity][keccak256(delegateType)][delegate] = now;
+    delegates[identity][keccak256(abi.encodePacked(delegateType))][delegate] = now;
     emit DIDDelegateChanged(identity, delegateType, delegate, now, changed[identity]);
     changed[identity] = block.number;
   }
@@ -95,36 +145,51 @@ contract EthereumDIDRegistry {
   }
 
   function revokeDelegateSigned(address identity, uint8 sigV, bytes32 sigR, bytes32 sigS, bytes32 delegateType, address delegate) public {
-    bytes32 hash = keccak256(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "revokeDelegate", delegateType, delegate);
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "revokeDelegate", delegateType, delegate));
     revokeDelegate(identity, checkSignature(identity, sigV, sigR, sigS, hash), delegateType, delegate);
   }
 
-  function setAttribute(address identity, address actor, bytes32 name, bytes value, uint validity ) internal onlyOwner(identity, actor) {
+  function revokeDelegateSigned(address identity, bytes memory signature, bytes32 delegateType, address delegate) public {
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "revokeDelegate", delegateType, delegate));
+    revokeDelegate(identity, checkSignature(identity, hash, signature), delegateType, delegate);
+  }
+
+  function setAttribute(address identity, address actor, bytes32 name, bytes memory value, uint validity ) internal onlyOwner(identity, actor) {
     emit DIDAttributeChanged(identity, name, value, now + validity, changed[identity]);
     changed[identity] = block.number;
   }
 
-  function setAttribute(address identity, bytes32 name, bytes value, uint validity) public {
+  function setAttribute(address identity, bytes32 name, bytes memory value, uint validity) public {
     setAttribute(identity, msg.sender, name, value, validity);
   }
 
-  function setAttributeSigned(address identity, uint8 sigV, bytes32 sigR, bytes32 sigS, bytes32 name, bytes value, uint validity) public {
-    bytes32 hash = keccak256(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "setAttribute", name, value, validity);
+  function setAttributeSigned(address identity, uint8 sigV, bytes32 sigR, bytes32 sigS, bytes32 name, bytes memory value, uint validity) public {
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "setAttribute", name, value, validity));
     setAttribute(identity, checkSignature(identity, sigV, sigR, sigS, hash), name, value, validity);
   }
 
-  function revokeAttribute(address identity, address actor, bytes32 name, bytes value ) internal onlyOwner(identity, actor) {
+  function setAttributeSigned(address identity, bytes memory signature, bytes32 name, bytes memory value, uint validity) public {
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "setAttribute", name, value, validity));
+    setAttribute(identity, checkSignature(identity, hash, signature), name, value, validity);
+  }
+
+  function revokeAttribute(address identity, address actor, bytes32 name, bytes memory value ) internal onlyOwner(identity, actor) {
     emit DIDAttributeChanged(identity, name, value, 0, changed[identity]);
     changed[identity] = block.number;
   }
 
-  function revokeAttribute(address identity, bytes32 name, bytes value) public {
+  function revokeAttribute(address identity, bytes32 name, bytes memory value) public {
     revokeAttribute(identity, msg.sender, name, value);
   }
 
- function revokeAttributeSigned(address identity, uint8 sigV, bytes32 sigR, bytes32 sigS, bytes32 name, bytes value) public {
-    bytes32 hash = keccak256(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "revokeAttribute", name, value); 
+ function revokeAttributeSigned(address identity, uint8 sigV, bytes32 sigR, bytes32 sigS, bytes32 name, bytes memory value) public {
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "revokeAttribute", name, value)); 
     revokeAttribute(identity, checkSignature(identity, sigV, sigR, sigS, hash), name, value);
   }
 
+ function revokeAttributeSigned(address identity, bytes memory signature, bytes32 name, bytes memory value) public {
+    bytes32 hash = keccak256(abi.encodePacked(byte(0x19), byte(0), this, nonce[identityOwner(identity)], identity, "revokeAttribute", name, value)); 
+    revokeAttribute(identity, checkSignature(identity, hash, signature), name, value);
+  }
+
 }

contracts/IERC1271.sol

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: CC0-1.0
+pragma solidity ^0.5.16;
+
+/**
+ * @notice ERC-1271: Standard Signature Validation Method for Contracts
+ */
+contract ERC1271 {
+
+  // bytes4(keccak256("isValidSignature(bytes32,bytes)")
+  bytes4 constant internal MAGICVALUE = 0x1626ba7e;
+
+  /**
+   * @dev Should return whether the signature provided is valid for the provided data
+   * @param _hash Arbitrary length data signed on the behalf of address(this)
+   * @param _signature Signature byte array associated with _hash
+   *
+   * MUST return the bytes4 magic value 0x1626ba7e when function passes.
+   * MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for solc > 0.5)
+   * MUST allow external calls
+   */ 
+  function isValidSignature(
+    bytes32 _hash, 
+    bytes memory _signature)
+    public
+    view 
+    returns (bytes4 magicValue);
+}

contracts/Migrations.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.17;
+pragma solidity ^0.5.16;
 
 contract Migrations {
   address public owner;
@@ -8,7 +8,7 @@ contract Migrations {
     if (msg.sender == owner) _;
   }
 
-  function Migrations() public {
+  constructor() public {
     owner = msg.sender;
   }
 

migrations/2_erc1271_sample.js

@@ -0,0 +1,6 @@
+var ERC1271Sample = artifacts.require("ERC1271Sample");
+
+module.exports = function(deployer) {
+  // deployment steps
+  deployer.deploy(ERC1271Sample);
+};