Merge pull request #17 from svandisproject/audit_updates

Audit updates

EIP20Interface.sol

@@ -2,7 +2,6 @@
 // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
 pragma solidity ^0.4.19;
 
-
 contract EIP20Interface {
     uint256 public totalSupply;
     function balanceOf(address _owner) public view returns (uint256 balance);
@@ -13,4 +12,4 @@ contract EIP20Interface {
 
     event Transfer(address indexed _from, address indexed _to, uint256 _value);
     event Approval(address indexed _owner, address indexed _spender, uint256 _value);
-}
+}

Sale.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.4.21;
 import "./Svandis.sol";
 
 contract Sale is Svandis {
-
+    using SafeMath for uint256;
     address owner;
     address withdrawWallet;
     uint256 public tier1Rate;
@@ -14,6 +14,7 @@ contract Sale is Svandis {
     uint256 public preSaleRate;
     mapping(uint8 => uint256) public tierToRates;
     mapping (address => uint256) public companyAllowed;
+    mapping (address => uint256) public contributorAllowed;
 
     constructor() public {
         owner = msg.sender;
@@ -59,7 +60,7 @@ contract Sale is Svandis {
 
     function addToWhitelist(address _whitelisted, uint256 _quantity) public onlyOwner returns (bool success) {
         require(_quantity <= balances[this]);
-        allowed[this][_whitelisted] = _quantity;
+        contributorAllowed[_whitelisted] = _quantity;
         return true;
     }
 
@@ -79,7 +80,7 @@ contract Sale is Svandis {
     }
 
     function removeFromWhitelist(address _whitelisted) public onlyOwner returns (bool success) {
-        allowed[this][_whitelisted] = 0;
+        contributorAllowed[_whitelisted] = 0;
         return true;
     }
 
@@ -89,7 +90,7 @@ contract Sale is Svandis {
     }
 
     function checkWhitelisted(address _whitelisted) public view onlyOwner returns (uint256 quantity) {
-        return allowed[this][_whitelisted];
+        return contributorAllowed[_whitelisted];
     }
 
     function checkCompanyWhitelisted(address _whitelisted) public view onlyOwner returns (uint256 quantity) {
@@ -120,22 +121,26 @@ contract Sale is Svandis {
     }
 
     function buyTokens() public saleOngoing payable {
-        uint256 quantity = (msg.value * tierToRates[currentTier])/(1 ether);
-        require(quantity <= allowed[this][msg.sender]);
+        uint256 quantity = (msg.value * tierToRates[currentTier]).div(1 ether);
+        require(quantity <= contributorAllowed[msg.sender]);
 
-        balances[msg.sender] += quantity;
-        balances[address(this)] -= quantity;
-        allowed[this][msg.sender] -= quantity;
+        balances[msg.sender] = balances[msg.sender].add(quantity);
+        balances[address(this)] = balances[address(this)].sub(quantity);
+        contributorAllowed[msg.sender] = contributorAllowed[msg.sender].sub(quantity);
 
         withdrawWallet.transfer(msg.value);
         emit Transfer(this, msg.sender, quantity);
     }
 
     function takeCompanyTokensOwnership() public {
-        balances[msg.sender] += companyAllowed[msg.sender];
-        balances[address(this)] -= companyAllowed[msg.sender];
+        balances[msg.sender] = balances[msg.sender].add(companyAllowed[msg.sender]);
+        balances[address(this)] = balances[address(this)].sub(companyAllowed[msg.sender]);
 
         emit Transfer(this, msg.sender, companyAllowed[msg.sender]);
         companyAllowed[msg.sender] = 0;
     }
+
+    function transferAnyEIP20Token(address tokenAddress, uint tokens) public onlyOwner returns (bool success) {
+        return EIP20Interface(tokenAddress).transfer(owner, tokens);
+    }
 }

Svandis.sol

@@ -2,12 +2,30 @@ pragma solidity ^0.4.21;
 
 import "./EIP20Interface.sol";
 
+library SafeMath {
+    function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
+        c = a + b;
+        require(c >= a);
+    }
+    function sub(uint256 a, uint256 b) internal pure returns (uint256 c) {
+        require(b <= a);
+        c = a - b;
+    }
+    function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
+        c = a * b;
+        require(a == 0 || c / a == b);
+    }
+    function div(uint256 a, uint256 b) internal pure returns (uint256 c) {
+        require(b > 0);
+        c = a / b;
+    }
+}
 
 contract Svandis is EIP20Interface {
-
+    using SafeMath for uint256;
     uint256 constant private MAX_UINT256 = 2**256 - 1;
     uint256 constant public totalSupply = 400000000000000000000000000;
-    uint256 constant public decimals = 18;
+    uint8 constant public decimals = 18;
 
     mapping (address => uint256) public balances;
     mapping (address => mapping (address => uint256)) public allowed;
@@ -18,8 +36,8 @@ contract Svandis is EIP20Interface {
 
     function transfer(address _to, uint256 _value) public returns (bool success) {
         require(balances[msg.sender] >= _value);
-        balances[msg.sender] -= _value;
-        balances[_to] += _value;
+        balances[msg.sender] = balances[msg.sender].sub(_value);
+        balances[_to] = balances[_to].add(_value);
         emit Transfer(msg.sender, _to, _value);
         return true;
     }
@@ -28,10 +46,10 @@ contract Svandis is EIP20Interface {
         uint256 allowance = allowed[_from][msg.sender];
         require(balances[_from] >= _value && allowance >= _value);
         require(_from != address(this));
-        balances[_to] += _value;
-        balances[_from] -= _value;
+        balances[_to] = balances[_to].add(_value);
+        balances[_from] = balances[_from].sub(_value);
         if (allowance < MAX_UINT256) {
-            allowed[_from][msg.sender] -= _value;
+            allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
         }
         emit Transfer(_from, _to, _value);
         return true;