// File: contracts/token/MintableToken.sol pragma solidity <0.6 >=0.4.24; interface MintableToken { function mint(address, uint) external returns (bool); function burn(uint) external returns (bool); } // File: contracts/token/ERC20Basic.sol pragma solidity <0.6 >=0.4.21; /** * @title ERC20Basic * @dev Simpler version of ERC20 interface * @dev see https://github.com/ethereum/EIPs/issues/179 */ contract ERC20Basic { function totalSupply() public view returns (uint256); function balanceOf(address who) public view returns (uint256); function transfer(address to, uint256 value) public returns (bool); event Transfer(address indexed from, address indexed to, uint256 value); } // File: contracts/math/SafeMath.sol pragma solidity <0.6 >=0.4.21; /** * @title SafeMath * @dev Math operations with safety checks that throw on error */ library SafeMath { /** * @dev Multiplies two numbers, throws on overflow. */ /*@CTK SafeMath_mul @tag spec @post __reverted == __has_assertion_failure @post __has_assertion_failure == __has_overflow @post __reverted == false -> c == a * b @post msg == msg__post */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function mul(uint256 a, uint256 b) internal pure returns (uint256 c) { if (a == 0) { return 0; } c = a * b; assert(c / a == b); return c; } /** * @dev Integer division of two numbers, truncating the quotient. */ /*@CTK SafeMath_div @tag spec @pre b != 0 @post __reverted == __has_assertion_failure @post __has_overflow == true -> __has_assertion_failure == true @post __reverted == false -> __return == a / b @post msg == msg__post */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function div(uint256 a, uint256 b) internal pure returns (uint256) { // assert(b > 0); // Solidity automatically throws when dividing by 0 // uint256 c = a / b; // assert(a == b * c + a % b); // There is no case in which this doesn't hold return a / b; } /** * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend). */ /*@CTK SafeMath_sub @tag spec @post __reverted == __has_assertion_failure @post __has_overflow == true -> __has_assertion_failure == true @post __reverted == false -> __return == a - b @post msg == msg__post */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { assert(b <= a); return a - b; } /** * @dev Adds two numbers, throws on overflow. */ /*@CTK SafeMath_add @tag spec @post __reverted == __has_assertion_failure @post __has_assertion_failure == __has_overflow @post __reverted == false -> c == a + b @post msg == msg__post */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function add(uint256 a, uint256 b) internal pure returns (uint256 c) { c = a + b; assert(c >= a); return c; } } // File: contracts/token/BasicToken.sol pragma solidity <0.6 >=0.4.21; /** * @title Basic token * @dev Basic version of StandardToken, with no allowances. */ contract BasicToken is ERC20Basic { using SafeMath for uint256; mapping(address => uint256) balances; uint256 totalSupply_; /** * @dev total number of tokens in existence */ function totalSupply() public view returns (uint256) { return totalSupply_; } /** * @dev transfer token for a specified address * @param _to The address to transfer to. * @param _value The amount to be transferred. */ /*@CTK transfer_success @pre _to != address(0) @pre balances[msg.sender] >= _value @pre __reverted == false @post __reverted == false @post __return == true */ /*@CTK transfer_same_address @tag no_overflow @pre _to == msg.sender @post this == __post */ /*@CTK transfer_conditions @tag assume_completion @pre _to != msg.sender @post __post.balances[_to] == balances[_to] + _value @post __post.balances[msg.sender] == balances[msg.sender] - _value */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function transfer(address _to, uint256 _value) public returns (bool) { require(_to != address(0)); require(_value <= balances[msg.sender]); balances[msg.sender] = balances[msg.sender].sub(_value); balances[_to] = balances[_to].add(_value); emit Transfer(msg.sender, _to, _value); return true; } /** * @dev Gets the balance of the specified address. * @param _owner The address to query the the balance of. * @return An uint256 representing the amount owned by the passed address. */ /*@CTK balanceOf @post __reverted == false @post __return == balances[_owner] */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function balanceOf(address _owner) public view returns (uint256) { return balances[_owner]; } } // File: contracts/token/ERC20.sol pragma solidity <0.6 >=0.4.21; /** * @title ERC20 interface * @dev see https://github.com/ethereum/EIPs/issues/20 */ contract ERC20 is ERC20Basic { function allowance(address owner, address spender) public view returns (uint256); function transferFrom(address from, address to, uint256 value) public returns (bool); function approve(address spender, uint256 value) public returns (bool); event Approval(address indexed owner, address indexed spender, uint256 value); } // File: contracts/token/StandardToken.sol pragma solidity <0.6 >=0.4.21; /** * @title Standard ERC20 token * * @dev Implementation of the basic standard token. * @dev https://github.com/ethereum/EIPs/issues/20 * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol */ contract StandardToken is ERC20, BasicToken { mapping (address => mapping (address => uint256)) internal allowed; /** * @dev Transfer tokens from one address to another * @param _from address The address which you want to send tokens from * @param _to address The address which you want to transfer to * @param _value uint256 the amount of tokens to be transferred */ /*@CTK transferFrom @tag assume_completion @pre _from != _to @post __return == true @post __post.balances[_to] == balances[_to] + _value @post __post.balances[_from] == balances[_from] - _value @post __has_overflow == false */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function transferFrom(address _from, address _to, uint256 _value) public returns (bool) { require(_to != address(0)); require(_value <= balances[_from]); require(_value <= allowed[_from][msg.sender]); balances[_from] = balances[_from].sub(_value); balances[_to] = balances[_to].add(_value); allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value); emit Transfer(_from, _to, _value); return true; } /** * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender. * * Beware that changing an allowance with this method brings the risk that someone may use both the old * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards: * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 * @param _spender The address which will spend the funds. * @param _value The amount of tokens to be spent. */ /*@CTK approve_success @post _value == 0 -> __reverted == false @post allowed[msg.sender][_spender] == 0 -> __reverted == false */ /*@CTK approve @tag assume_completion @post __post.allowed[msg.sender][_spender] == _value */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function approve(address _spender, uint256 _value) public returns (bool) { allowed[msg.sender][_spender] = _value; emit Approval(msg.sender, _spender, _value); return true; } /** * @dev Function to check the amount of tokens that an owner allowed to a spender. * @param _owner address The address which owns the funds. * @param _spender address The address which will spend the funds. * @return A uint256 specifying the amount of tokens still available for the spender. */ function allowance(address _owner, address _spender) public view returns (uint256) { return allowed[_owner][_spender]; } /** * @dev Increase the amount of tokens that an owner allowed to a spender. * * approve should be called when allowed[_spender] == 0. To increment * allowed value is better to use this function to avoid 2 calls (and wait until * the first transaction is mined) * From MonolithDAO Token.sol * @param _spender The address which will spend the funds. * @param _addedValue The amount of tokens to increase the allowance by. */ /*@CTK CtkIncreaseApprovalEffect @tag assume_completion @post __post.allowed[msg.sender][_spender] == allowed[msg.sender][_spender] + _addedValue @post __has_overflow == false */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function increaseApproval(address _spender, uint _addedValue) public returns (bool) { allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue); emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]); return true; } /** * @dev Decrease the amount of tokens that an owner allowed to a spender. * * approve should be called when allowed[_spender] == 0. To decrement * allowed value is better to use this function to avoid 2 calls (and wait until * the first transaction is mined) * From MonolithDAO Token.sol * @param _spender The address which will spend the funds. * @param _subtractedValue The amount of tokens to decrease the allowance by. */ /*@CTK CtkDecreaseApprovalEffect_1 @pre allowed[msg.sender][_spender] >= _subtractedValue @tag assume_completion @post __post.allowed[msg.sender][_spender] == allowed[msg.sender][_spender] - _subtractedValue @post __has_overflow == false */ /*@CTK CtkDecreaseApprovalEffect_2 @pre allowed[msg.sender][_spender] < _subtractedValue @tag assume_completion @post __post.allowed[msg.sender][_spender] == 0 @post __has_overflow == false */ /* CertiK Smart Labelling, for more details visit: https://certik.org */ function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) { uint oldValue = allowed[msg.sender][_spender]; if (_subtractedValue > oldValue) { allowed[msg.sender][_spender] = 0; } else { allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue); } emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]); return true; } } // File: contracts/ownership/Ownable.sol pragma solidity <6.0 >=0.4.0; /** * @title Ownable * @dev The Ownable contract has an owner address, and provides basic authorization control * functions, this simplifies the implementation of "user permissions". */ contract Ownable { address public owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev The Ownable constructor sets the original `owner` of the contract to the sender * account. */ constructor() public { owner = msg.sender; } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { require(msg.sender == owner); _; } /** * @dev Allows the current owner to transfer control of the contract to a newOwner. * @param newOwner The address to transfer ownership to. */ function transferOwnership(address newOwner) public onlyOwner { require(newOwner != address(0)); emit OwnershipTransferred(owner, newOwner); owner = newOwner; } } // File: contracts/lifecycle/Pausable.sol pragma solidity <0.6 >=0.4.24; /** * @title Pausable * @dev Base contract which allows children to implement an emergency stop mechanism. */ contract Pausable is Ownable { event Pause(); event Unpause(); bool public paused = false; /** * @dev Modifier to make a function callable only when the contract is not paused. */ modifier whenNotPaused() { require(!paused); _; } /** * @dev Modifier to make a function callable only when the contract is paused. */ modifier whenPaused() { require(paused); _; } /** * @dev called by the owner to pause, triggers stopped state */ function pause() onlyOwner whenNotPaused public { paused = true; emit Pause(); } /** * @dev called by the owner to unpause, returns to normal state */ function unpause() onlyOwner whenPaused public { paused = false; emit Unpause(); } } // File: contracts/token/ShadowToken.sol pragma solidity <0.6 >=0.4.24; contract ShadowToken is StandardToken, MintableToken, Pausable { event Minted(address indexed to, uint256 amount); event Burned(address indexed from, uint256 amount); event MinterAdded(address indexed minter); event MinterRemoved(address indexed minter); modifier onlyMinter() { require(minter == msg.sender, "not the minter"); _; } address public coToken; address public minter; string public name; string public symbol; uint8 public decimals; constructor(address _minter, address _coToken, string memory _name, string memory _symbol, uint8 _decimals) public { minter = _minter; coToken = _coToken; name = _name; symbol = _symbol; decimals = _decimals; emit MinterAdded(_minter); } function mint(address _to, uint256 _amount) public onlyMinter whenNotPaused returns (bool) { totalSupply_ = totalSupply_.add(_amount); balances[_to] = balances[_to].add(_amount); emit Minted(_to, _amount); emit Transfer(address(0), _to, _amount); return true; } // user can also burn by sending token to address(0), but this function will emit Burned event function burn(uint256 _amount) public returns (bool) { require(balances[msg.sender] >= _amount); totalSupply_ = totalSupply_.sub(_amount); balances[msg.sender] = balances[msg.sender].sub(_amount); emit Burned(msg.sender, _amount); emit Transfer(msg.sender, address(0), _amount); return true; } }