Contract Name:
SyntheticSyndicateERC20
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../utils/ERC20.sol";
import "../utils/AccessControl.sol";
contract SyntheticSyndicateERC20 is ERC20("Synthetic Syndicate Token", "sSYNR"), AccessControl {
/**
* @dev Smart contract unique identifier, a random number
* @dev Should be regenerated each time smart contact source code is changed
* and changes smart contract itself is to be redeployed
* @dev Generated using https://www.random.org/bytes/
*/
uint256 public constant TOKEN_UID = 0xac3051b8d4f50966afb632468a4f61483ae6a953b74e387a01ef94316d6b7d62;
uint32 public constant ROLE_TOKEN_DESTROYER = 0x0002_0000;
uint32 public constant ROLE_WHITE_LISTED_RECEIVER = 0x0004_0000;
constructor(address _superAdmin) AccessControl(_superAdmin) {}
/**
* @notice Must be called by ROLE_TOKEN_CREATOR addresses.
*
* @param recipient address to receive the tokens.
* @param amount number of tokens to be minted.
*/
function mint(address recipient, uint256 amount) external {
require(isSenderInRole(ROLE_TOKEN_CREATOR), "sSYNR: insufficient privileges (ROLE_TOKEN_CREATOR required)");
_mint(recipient, amount);
}
/**
* @param amount number of tokens to be burned.
*/
function burn(uint256 amount) external {
_burn(msg.sender, amount);
}
/**
* @notice Must be called by ROLE_TOKEN_DESTROYER addresses (SynrSwapper)
* Can burn only tokens owned by ROLE_WHITE_LISTED_RECEIVER address
* @param recipient address to burn the tokens.
* @param amount number of tokens to be burned
*/
function burn(address recipient, uint256 amount) external {
require(isSenderInRole(ROLE_TOKEN_DESTROYER), "sSYNR: insufficient privileges (ROLE_TOKEN_DESTROYER required)");
require(isOperatorInRole(recipient, ROLE_WHITE_LISTED_RECEIVER), "sSYNR: Non Allowed Receiver");
_burn(recipient, amount);
}
function _transfer(
address sender,
address recipient,
uint256 amount
) internal virtual override {
require(isOperatorInRole(recipient, ROLE_WHITE_LISTED_RECEIVER), "sSYNR: Non Allowed Receiver");
super._transfer(sender, recipient, amount);
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../interfaces/IERC20.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of returning `false` on failure. This behavior is nonetheless conventional
* and does not conflict with the expectations of ERC20 applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
// Copied from Open Zeppelin
contract ERC20 is IERC20 {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
uint8 private _decimals;
/**
* @notice Token creator is responsible for creating (minting)
* tokens to an arbitrary address
* @dev Role ROLE_TOKEN_CREATOR allows minting tokens
* (calling `mint` function)
*/
uint32 public constant ROLE_TOKEN_CREATOR = 0x0001_0000;
/**
* @dev Sets the values for {name} and {symbol}, initializes {decimals} with
* a default value of 18.
*
* To select a different value for {decimals}, use {_setupDecimals}.
*
* All three of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
_decimals = 18;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
* called.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual returns (uint8) {
return _decimals;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(msg.sender, recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(msg.sender, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, msg.sender, _allowances[sender][msg.sender] - amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(msg.sender, spender, _allowances[msg.sender][spender] + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(msg.sender, spender, _allowances[msg.sender][spender] - subtractedValue);
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(
address sender,
address recipient,
uint256 amount
) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
_balances[sender] = _balances[sender] - amount;
_balances[recipient] = _balances[recipient] + amount;
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply = _totalSupply + amount;
_balances[account] = _balances[account] + amount;
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account] - amount;
_totalSupply = _totalSupply - amount;
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Sets {decimals} to a value other than the default one of 18.
*
* WARNING: This function should only be called from the constructor. Most
* applications that interact with token contracts will not expect
* {decimals} to ever change, and may work incorrectly if it does.
*/
function _setupDecimals(uint8 decimals_) internal virtual {
_decimals = decimals_;
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be to transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
// import "hardhat/console.sol";
/**
* @title Access Control List
*
* @notice Access control smart contract provides an API to check
* if specific operation is permitted globally and/or
* if particular user has a permission to execute it.
*
* @notice It deals with two main entities: features and roles.
*
* @notice Features are designed to be used to enable/disable specific
* functions (public functions) of the smart contract for everyone.
* @notice User roles are designed to restrict access to specific
* functions (restricted functions) of the smart contract to some users.
*
* @notice Terms "role", "permissions" and "set of permissions" have equal meaning
* in the documentation text and may be used interchangeably.
* @notice Terms "permission", "single permission" implies only one permission bit set.
*
* @dev This smart contract is designed to be inherited by other
* smart contracts which require access control management capabilities.
*
* @author Basil Gorin
*/
contract AccessControl {
/**
* @notice Access manager is responsible for assigning the roles to users,
* enabling/disabling global features of the smart contract
* @notice Access manager can add, remove and update user roles,
* remove and update global features
*
* @dev Role ROLE_ACCESS_MANAGER allows modifying user roles and global features
* @dev Role ROLE_ACCESS_MANAGER has single bit at position 255 enabled
*/
uint256 public constant ROLE_ACCESS_MANAGER = 0x8000000000000000000000000000000000000000000000000000000000000000;
/**
* @dev Bitmask representing all the possible permissions (super admin role)
* @dev Has all the bits are enabled (2^256 - 1 value)
*/
// solhint-disable-next-line
uint256 private constant FULL_PRIVILEGES_MASK = type(uint256).max; // before 0.8.0: uint256(-1) overflows to 0xFFFF...
/**
* @notice Privileged addresses with defined roles/permissions
* @notice In the context of ERC20/ERC721 tokens these can be permissions to
* allow minting or burning tokens, transferring on behalf and so on
*
* @dev Maps user address to the permissions bitmask (role), where each bit
* represents a permission
* @dev Bitmask 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
* represents all possible permissions
* @dev Zero address mapping represents global features of the smart contract
*/
mapping(address => uint256) public userRoles;
/**
* @dev Fired in updateRole() and updateFeatures()
*
* @param _by operator which called the function
* @param _to address which was granted/revoked permissions
* @param _requested permissions requested
* @param _actual permissions effectively set
*/
event RoleUpdated(address indexed _by, address indexed _to, uint256 _requested, uint256 _actual);
/**
* @notice Creates an access control instance,
* setting contract creator to have full privileges
*/
constructor(address _superAdmin) {
userRoles[_superAdmin] = FULL_PRIVILEGES_MASK;
userRoles[msg.sender] = FULL_PRIVILEGES_MASK;
}
/**
* @notice Retrieves globally set of features enabled
*
* @dev Auxiliary getter function to maintain compatibility with previous
* versions of the Access Control List smart contract, where
* features was a separate uint256 public field
*
* @return 256-bit bitmask of the features enabled
*/
function features() public view returns (uint256) {
// according to new design features are stored in zero address
// mapping of `userRoles` structure
return userRoles[address(0)];
}
/**
* @notice Updates set of the globally enabled features (`features`),
* taking into account sender's permissions
*
* @dev Requires transaction sender to have `ROLE_ACCESS_MANAGER` permission
* @dev Function is left for backward compatibility with older versions
*
* @param _mask bitmask representing a set of features to enable/disable
*/
function updateFeatures(uint256 _mask) public {
// delegate call to `updateRole`
updateRole(address(0), _mask);
}
/**
* @notice Updates set of permissions (role) for a given user,
* taking into account sender's permissions.
*
* @dev Setting role to zero is equivalent to removing an all permissions
* @dev Setting role to `FULL_PRIVILEGES_MASK` is equivalent to
* copying senders' permissions (role) to the user
* @dev Requires transaction sender to have `ROLE_ACCESS_MANAGER` permission
*
* @param operator address of a user to alter permissions for or zero
* to alter global features of the smart contract
* @param role bitmask representing a set of permissions to
* enable/disable for a user specified
*/
function updateRole(address operator, uint256 role) public {
// caller must have a permission to update user roles
require(isSenderInRole(ROLE_ACCESS_MANAGER), "insufficient privileges (ROLE_ACCESS_MANAGER required)");
// evaluate the role and reassign it
userRoles[operator] = evaluateBy(msg.sender, userRoles[operator], role);
// fire an event
emit RoleUpdated(msg.sender, operator, role, userRoles[operator]);
}
/**
* @notice Determines the permission bitmask an operator can set on the
* target permission set
* @notice Used to calculate the permission bitmask to be set when requested
* in `updateRole` and `updateFeatures` functions
*
* @dev Calculated based on:
* 1) operator's own permission set read from userRoles[operator]
* 2) target permission set - what is already set on the target
* 3) desired permission set - what do we want set target to
*
* @dev Corner cases:
* 1) Operator is super admin and its permission set is `FULL_PRIVILEGES_MASK`:
* `desired` bitset is returned regardless of the `target` permission set value
* (what operator sets is what they get)
* 2) Operator with no permissions (zero bitset):
* `target` bitset is returned regardless of the `desired` value
* (operator has no authority and cannot modify anything)
*
* @dev Example:
* Consider an operator with the permissions bitmask 00001111
* is about to modify the target permission set 01010101
* Operator wants to set that permission set to 00110011
* Based on their role, an operator has the permissions
* to update only lowest 4 bits on the target, meaning that
* high 4 bits of the target set in this example is left
* unchanged and low 4 bits get changed as desired: 01010011
*
* @param operator address of the contract operator which is about to set the permissions
* @param target input set of permissions to operator is going to modify
* @param desired desired set of permissions operator would like to set
* @return resulting set of permissions given operator will set
*/
function evaluateBy(
address operator,
uint256 target,
uint256 desired
) public view returns (uint256) {
// read operator's permissions
uint256 p = userRoles[operator];
// taking into account operator's permissions,
// 1) enable the permissions desired on the `target`
target |= p & desired;
// 2) disable the permissions desired on the `target`
target &= FULL_PRIVILEGES_MASK ^ (p & (FULL_PRIVILEGES_MASK ^ desired));
// return calculated result
return target;
}
/**
* @notice Checks if requested set of features is enabled globally on the contract
*
* @param required set of features to check against
* @return true if all the features requested are enabled, false otherwise
*/
function isFeatureEnabled(uint256 required) public view returns (bool) {
// delegate call to `__hasRole`, passing `features` property
return __hasRole(features(), required);
}
/**
* @notice Checks if transaction sender `msg.sender` has all the permissions required
*
* @param required set of permissions (role) to check against
* @return true if all the permissions requested are enabled, false otherwise
*/
function isSenderInRole(uint256 required) public view returns (bool) {
// delegate call to `isOperatorInRole`, passing transaction sender
return isOperatorInRole(msg.sender, required);
}
/**
* @notice Checks if operator has all the permissions (role) required
*
* @param operator address of the user to check role for
* @param required set of permissions (role) to check
* @return true if all the permissions requested are enabled, false otherwise
*/
function isOperatorInRole(address operator, uint256 required) public view returns (bool) {
// delegate call to `__hasRole`, passing operator's permissions (role)
return __hasRole(userRoles[operator], required);
}
/**
* @dev Checks if role `actual` contains all the permissions required `required`
*
* @param actual existent role
* @param required required role
* @return true if actual has required role (all permissions), false otherwise
*/
function __hasRole(uint256 actual, uint256 required) internal pure returns (bool) {
// check the bitmask for the role required and return the result
return actual & required == required;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: 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
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}