Contract Source Code:
pragma solidity ^0.5.0;
import "@openzeppelin/contracts/GSN/Context.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/introspection/ERC165.sol";
/**
* @title ERC-721 Non-Fungible Token with optional enumeration extension logic
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
contract ERC721CustomEnumerable is Context, ERC165, ERC721, IERC721Enumerable {
// Mapping from owner to list of owned token IDs
mapping(address => uint256[]) private _ownedTokens;
// Mapping from token ID to index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;
uint256 public _totalSupply;
/*
* bytes4(keccak256('totalSupply()')) == 0x18160ddd
* bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59
* bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7
*
* => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63
*/
bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;
/**
* @dev Constructor function.
*/
constructor () public {
// register the supported interface to conform to ERC721Enumerable via ERC165
_registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
}
/**
* @dev Gets the total amount of tokens stored by the contract.
* @return uint256 representing the total amount of tokens
*/
function totalSupply() public view returns (uint256) {
return _totalSupply;
}
/**
* @dev Gets the token ID at a given index of the tokens list of the requested owner.
* @param owner address owning the tokens list to be accessed
* @param index uint256 representing the index to be accessed of the requested tokens list
* @return uint256 token ID at the given index of the tokens list owned by the requested address
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {
require(index < balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
return _ownedTokens[owner][index];
}
/**
* @dev Internal function to transfer ownership of a given token ID to another address.
* As opposed to transferFrom, this imposes no restrictions on msg.sender.
* @param from current owner of the token
* @param to address to receive the ownership of the given token ID
* @param tokenId uint256 ID of the token to be transferred
*/
function _transferFrom(address from, address to, uint256 tokenId) internal {
super._transferFrom(from, to, tokenId);
_removeTokenFromOwnerEnumeration(from, tokenId);
_addTokenToOwnerEnumeration(to, tokenId);
}
/**
* @dev Internal function to mint a new token.
* Reverts if the given token ID already exists.
* @param to address the beneficiary that will own the minted token
* @param tokenId uint256 ID of the token to be minted
*/
function _mint(address to, uint256 tokenId) internal {
super._mint(to, tokenId);
_addTokenToOwnerEnumeration(to, tokenId);
_totalSupply = _totalSupply.add(1);
}
/**
* @dev Internal function to burn a specific token.
* Reverts if the token does not exist.
* Deprecated, use {ERC721-_burn} instead.
* @param owner owner of the token to burn
* @param tokenId uint256 ID of the token being burned
*/
function _burn(address owner, uint256 tokenId) internal {
super._burn(owner, tokenId);
_removeTokenFromOwnerEnumeration(owner, tokenId);
// Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund
_ownedTokensIndex[tokenId] = 0;
_totalSupply = _totalSupply.sub(1);
}
/**
* @dev Gets the list of token IDs of the requested owner.
* @param owner address owning the tokens
* @return uint256[] List of token IDs owned by the requested address
*/
function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {
return _ownedTokens[owner];
}
/**
* @dev Private function to add a token to this extension's ownership-tracking data structures.
* @param to address representing the new owner of the given token ID
* @param tokenId uint256 ID of the token to be added to the tokens list of the given address
*/
function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
_ownedTokensIndex[tokenId] = _ownedTokens[to].length;
_ownedTokens[to].push(tokenId);
}
/**
* @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
* while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
* gas optimizations e.g. when performing a transfer operation (avoiding double writes).
* This has O(1) time complexity, but alters the order of the _ownedTokens array.
* @param from address representing the previous owner of the given token ID
* @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
*/
function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
// To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);
uint256 tokenIndex = _ownedTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary
if (tokenIndex != lastTokenIndex) {
uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
_ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
}
// This also deletes the contents at the last position of the array
_ownedTokens[from].length--;
// Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by
// lastTokenId, or just over the end of the array if the token was the last one).
}
/**
* @dev Gets the token ID at a given index of all the tokens in this contract
* Reverts if the index is greater or equal to the total number of tokens
* @param index uint256 representing the index to be accessed of the tokens list
* @return uint256 token ID at the given index of the tokens list
*/
function tokenByIndex(uint256 index) public view returns (uint256) {
require(index < totalSupply(), "Index is out of bounds.");
return index;
}
}
pragma solidity ^0.5.0;
/*
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with GSN meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
contract Context {
// Empty internal constructor, to prevent people from mistakenly deploying
// an instance of this contract, which should be used via inheritance.
constructor () internal { }
// solhint-disable-previous-line no-empty-blocks
function _msgSender() internal view returns (address payable) {
return msg.sender;
}
function _msgData() internal view returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
pragma solidity ^0.5.0;
import "./IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
contract IERC721Enumerable is IERC721 {
function totalSupply() public view returns (uint256);
function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);
function tokenByIndex(uint256 index) public view returns (uint256);
}
pragma solidity ^0.5.0;
import "../../introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
contract IERC721 is IERC165 {
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of NFTs in `owner`'s account.
*/
function balanceOf(address owner) public view returns (uint256 balance);
/**
* @dev Returns the owner of the NFT specified by `tokenId`.
*/
function ownerOf(uint256 tokenId) public view returns (address owner);
/**
* @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to
* another (`to`).
*
*
*
* Requirements:
* - `from`, `to` cannot be zero.
* - `tokenId` must be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this
* NFT by either {approve} or {setApprovalForAll}.
*/
function safeTransferFrom(address from, address to, uint256 tokenId) public;
/**
* @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to
* another (`to`).
*
* Requirements:
* - If the caller is not `from`, it must be approved to move this NFT by
* either {approve} or {setApprovalForAll}.
*/
function transferFrom(address from, address to, uint256 tokenId) public;
function approve(address to, uint256 tokenId) public;
function getApproved(uint256 tokenId) public view returns (address operator);
function setApprovalForAll(address operator, bool _approved) public;
function isApprovedForAll(address owner, address operator) public view returns (bool);
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;
}
pragma solidity ^0.5.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
pragma solidity ^0.5.0;
import "../../GSN/Context.sol";
import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
import "../../drafts/Counters.sol";
import "../../introspection/ERC165.sol";
/**
* @title ERC721 Non-Fungible Token Standard basic implementation
* @dev see https://eips.ethereum.org/EIPS/eip-721
*/
contract ERC721 is Context, ERC165, IERC721 {
using SafeMath for uint256;
using Address for address;
using Counters for Counters.Counter;
// Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
// which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;
// Mapping from token ID to owner
mapping (uint256 => address) private _tokenOwner;
// Mapping from token ID to approved address
mapping (uint256 => address) private _tokenApprovals;
// Mapping from owner to number of owned token
mapping (address => Counters.Counter) private _ownedTokensCount;
// Mapping from owner to operator approvals
mapping (address => mapping (address => bool)) private _operatorApprovals;
/*
* bytes4(keccak256('balanceOf(address)')) == 0x70a08231
* bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e
* bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3
* bytes4(keccak256('getApproved(uint256)')) == 0x081812fc
* bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465
* bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5
* bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd
* bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e
* bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde
*
* => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^
* 0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd
*/
bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
constructor () public {
// register the supported interfaces to conform to ERC721 via ERC165
_registerInterface(_INTERFACE_ID_ERC721);
}
/**
* @dev Gets the balance of the specified address.
* @param owner address to query the balance of
* @return uint256 representing the amount owned by the passed address
*/
function balanceOf(address owner) public view returns (uint256) {
require(owner != address(0), "ERC721: balance query for the zero address");
return _ownedTokensCount[owner].current();
}
/**
* @dev Gets the owner of the specified token ID.
* @param tokenId uint256 ID of the token to query the owner of
* @return address currently marked as the owner of the given token ID
*/
function ownerOf(uint256 tokenId) public view returns (address) {
address owner = _tokenOwner[tokenId];
require(owner != address(0), "ERC721: owner query for nonexistent token");
return owner;
}
/**
* @dev Approves another address to transfer the given token ID
* The zero address indicates there is no approved address.
* There can only be one approved address per token at a given time.
* Can only be called by the token owner or an approved operator.
* @param to address to be approved for the given token ID
* @param tokenId uint256 ID of the token to be approved
*/
function approve(address to, uint256 tokenId) public {
address owner = ownerOf(tokenId);
require(to != owner, "ERC721: approval to current owner");
require(_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
"ERC721: approve caller is not owner nor approved for all"
);
_tokenApprovals[tokenId] = to;
emit Approval(owner, to, tokenId);
}
/**
* @dev Gets the approved address for a token ID, or zero if no address set
* Reverts if the token ID does not exist.
* @param tokenId uint256 ID of the token to query the approval of
* @return address currently approved for the given token ID
*/
function getApproved(uint256 tokenId) public view returns (address) {
require(_exists(tokenId), "ERC721: approved query for nonexistent token");
return _tokenApprovals[tokenId];
}
/**
* @dev Sets or unsets the approval of a given operator
* An operator is allowed to transfer all tokens of the sender on their behalf.
* @param to operator address to set the approval
* @param approved representing the status of the approval to be set
*/
function setApprovalForAll(address to, bool approved) public {
require(to != _msgSender(), "ERC721: approve to caller");
_operatorApprovals[_msgSender()][to] = approved;
emit ApprovalForAll(_msgSender(), to, approved);
}
/**
* @dev Tells whether an operator is approved by a given owner.
* @param owner owner address which you want to query the approval of
* @param operator operator address which you want to query the approval of
* @return bool whether the given operator is approved by the given owner
*/
function isApprovedForAll(address owner, address operator) public view returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev Transfers the ownership of a given token ID to another address.
* Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
* Requires the msg.sender to be the owner, approved, or operator.
* @param from current owner of the token
* @param to address to receive the ownership of the given token ID
* @param tokenId uint256 ID of the token to be transferred
*/
function transferFrom(address from, address to, uint256 tokenId) public {
//solhint-disable-next-line max-line-length
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
_transferFrom(from, to, tokenId);
}
/**
* @dev Safely transfers the ownership of a given token ID to another address
* If the target address is a contract, it must implement {IERC721Receiver-onERC721Received},
* which is called upon a safe transfer, and return the magic value
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
* the transfer is reverted.
* Requires the msg.sender to be the owner, approved, or operator
* @param from current owner of the token
* @param to address to receive the ownership of the given token ID
* @param tokenId uint256 ID of the token to be transferred
*/
function safeTransferFrom(address from, address to, uint256 tokenId) public {
safeTransferFrom(from, to, tokenId, "");
}
/**
* @dev Safely transfers the ownership of a given token ID to another address
* If the target address is a contract, it must implement {IERC721Receiver-onERC721Received},
* which is called upon a safe transfer, and return the magic value
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
* the transfer is reverted.
* Requires the _msgSender() to be the owner, approved, or operator
* @param from current owner of the token
* @param to address to receive the ownership of the given token ID
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes data to send along with a safe transfer check
*/
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
_safeTransferFrom(from, to, tokenId, _data);
}
/**
* @dev Safely transfers the ownership of a given token ID to another address
* If the target address is a contract, it must implement `onERC721Received`,
* which is called upon a safe transfer, and return the magic value
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
* the transfer is reverted.
* Requires the msg.sender to be the owner, approved, or operator
* @param from current owner of the token
* @param to address to receive the ownership of the given token ID
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes data to send along with a safe transfer check
*/
function _safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) internal {
_transferFrom(from, to, tokenId);
require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
}
/**
* @dev Returns whether the specified token exists.
* @param tokenId uint256 ID of the token to query the existence of
* @return bool whether the token exists
*/
function _exists(uint256 tokenId) internal view returns (bool) {
address owner = _tokenOwner[tokenId];
return owner != address(0);
}
/**
* @dev Returns whether the given spender can transfer a given token ID.
* @param spender address of the spender to query
* @param tokenId uint256 ID of the token to be transferred
* @return bool whether the msg.sender is approved for the given token ID,
* is an operator of the owner, or is the owner of the token
*/
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
require(_exists(tokenId), "ERC721: operator query for nonexistent token");
address owner = ownerOf(tokenId);
return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
}
/**
* @dev Internal function to safely mint a new token.
* Reverts if the given token ID already exists.
* If the target address is a contract, it must implement `onERC721Received`,
* which is called upon a safe transfer, and return the magic value
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
* the transfer is reverted.
* @param to The address that will own the minted token
* @param tokenId uint256 ID of the token to be minted
*/
function _safeMint(address to, uint256 tokenId) internal {
_safeMint(to, tokenId, "");
}
/**
* @dev Internal function to safely mint a new token.
* Reverts if the given token ID already exists.
* If the target address is a contract, it must implement `onERC721Received`,
* which is called upon a safe transfer, and return the magic value
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
* the transfer is reverted.
* @param to The address that will own the minted token
* @param tokenId uint256 ID of the token to be minted
* @param _data bytes data to send along with a safe transfer check
*/
function _safeMint(address to, uint256 tokenId, bytes memory _data) internal {
_mint(to, tokenId);
require(_checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
}
/**
* @dev Internal function to mint a new token.
* Reverts if the given token ID already exists.
* @param to The address that will own the minted token
* @param tokenId uint256 ID of the token to be minted
*/
function _mint(address to, uint256 tokenId) internal {
require(to != address(0), "ERC721: mint to the zero address");
require(!_exists(tokenId), "ERC721: token already minted");
_tokenOwner[tokenId] = to;
_ownedTokensCount[to].increment();
emit Transfer(address(0), to, tokenId);
}
/**
* @dev Internal function to burn a specific token.
* Reverts if the token does not exist.
* Deprecated, use {_burn} instead.
* @param owner owner of the token to burn
* @param tokenId uint256 ID of the token being burned
*/
function _burn(address owner, uint256 tokenId) internal {
require(ownerOf(tokenId) == owner, "ERC721: burn of token that is not own");
_clearApproval(tokenId);
_ownedTokensCount[owner].decrement();
_tokenOwner[tokenId] = address(0);
emit Transfer(owner, address(0), tokenId);
}
/**
* @dev Internal function to burn a specific token.
* Reverts if the token does not exist.
* @param tokenId uint256 ID of the token being burned
*/
function _burn(uint256 tokenId) internal {
_burn(ownerOf(tokenId), tokenId);
}
/**
* @dev Internal function to transfer ownership of a given token ID to another address.
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
* @param from current owner of the token
* @param to address to receive the ownership of the given token ID
* @param tokenId uint256 ID of the token to be transferred
*/
function _transferFrom(address from, address to, uint256 tokenId) internal {
require(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
require(to != address(0), "ERC721: transfer to the zero address");
_clearApproval(tokenId);
_ownedTokensCount[from].decrement();
_ownedTokensCount[to].increment();
_tokenOwner[tokenId] = to;
emit Transfer(from, to, tokenId);
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
* The call is not executed if the target address is not a contract.
*
* This is an internal detail of the `ERC721` contract and its use is deprecated.
* @param from address representing the previous owner of the given token ID
* @param to target address that will receive the tokens
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes optional data to send along with the call
* @return bool whether the call correctly returned the expected magic value
*/
function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
internal returns (bool)
{
if (!to.isContract()) {
return true;
}
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = to.call(abi.encodeWithSelector(
IERC721Receiver(to).onERC721Received.selector,
_msgSender(),
from,
tokenId,
_data
));
if (!success) {
if (returndata.length > 0) {
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert("ERC721: transfer to non ERC721Receiver implementer");
}
} else {
bytes4 retval = abi.decode(returndata, (bytes4));
return (retval == _ERC721_RECEIVED);
}
}
/**
* @dev Private function to clear current approval of a given token ID.
* @param tokenId uint256 ID of the token to be transferred
*/
function _clearApproval(uint256 tokenId) private {
if (_tokenApprovals[tokenId] != address(0)) {
_tokenApprovals[tokenId] = address(0);
}
}
}
pragma solidity ^0.5.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
contract IERC721Receiver {
/**
* @notice Handle the receipt of an NFT
* @dev The ERC721 smart contract calls this function on the recipient
* after a {IERC721-safeTransferFrom}. This function MUST return the function selector,
* otherwise the caller will revert the transaction. The selector to be
* returned can be obtained as `this.onERC721Received.selector`. This
* function MAY throw to revert and reject the transfer.
* Note: the ERC721 contract address is always the message sender.
* @param operator The address which called `safeTransferFrom` function
* @param from The address which previously owned the token
* @param tokenId The NFT identifier which is being transferred
* @param data Additional data with no specified format
* @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
*/
function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
public returns (bytes4);
}
pragma solidity ^0.5.0;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*
* _Available since v2.4.0._
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*
* _Available since v2.4.0._
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*
* _Available since v2.4.0._
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
pragma solidity ^0.5.5;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
// solhint-disable-next-line no-inline-assembly
assembly { codehash := extcodehash(account) }
return (codehash != accountHash && codehash != 0x0);
}
/**
* @dev Converts an `address` into `address payable`. Note that this is
* simply a type cast: the actual underlying value is not changed.
*
* _Available since v2.4.0._
*/
function toPayable(address account) internal pure returns (address payable) {
return address(uint160(account));
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*
* _Available since v2.4.0._
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-call-value
(bool success, ) = recipient.call.value(amount)("");
require(success, "Address: unable to send value, recipient may have reverted");
}
}
pragma solidity ^0.5.0;
import "../math/SafeMath.sol";
/**
* @title Counters
* @author Matt Condon (@shrugs)
* @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
* of elements in a mapping, issuing ERC721 ids, or counting request ids.
*
* Include with `using Counters for Counters.Counter;`
* Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath}
* overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never
* directly accessed.
*/
library Counters {
using SafeMath for uint256;
struct Counter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
// this feature: see https://github.com/ethereum/solidity/issues/4637
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
// The {SafeMath} overflow check can be skipped here, see the comment at the top
counter._value += 1;
}
function decrement(Counter storage counter) internal {
counter._value = counter._value.sub(1);
}
}
pragma solidity ^0.5.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts may inherit from this and call {_registerInterface} to declare
* their support of an interface.
*/
contract ERC165 is IERC165 {
/*
* bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
*/
bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
/**
* @dev Mapping of interface ids to whether or not it's supported.
*/
mapping(bytes4 => bool) private _supportedInterfaces;
constructor () internal {
// Derived contracts need only register support for their own interfaces,
// we register support for ERC165 itself here
_registerInterface(_INTERFACE_ID_ERC165);
}
/**
* @dev See {IERC165-supportsInterface}.
*
* Time complexity O(1), guaranteed to always use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool) {
return _supportedInterfaces[interfaceId];
}
/**
* @dev Registers the contract as an implementer of the interface defined by
* `interfaceId`. Support of the actual ERC165 interface is automatic and
* registering its interface id is not required.
*
* See {IERC165-supportsInterface}.
*
* Requirements:
*
* - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
*/
function _registerInterface(bytes4 interfaceId) internal {
require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
_supportedInterfaces[interfaceId] = true;
}
}
pragma solidity ^0.5.5;
import "@openzeppelin/contracts/ownership/Ownable.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721Metadata.sol";
import "@openzeppelin/contracts/cryptography/MerkleProof.sol";
import "./Minter.sol";
import "./Utils.sol";
interface ITokenCategories {
function getTokenCategory(uint256 tokenId) external pure returns (string memory);
}
contract HPToken is Utils, ERC721Metadata, Ownable, Minter {
string private _baseURI;
address private _categoriesContrAddr;
uint256 private _totalSupply;
bytes32 private _rootHash;
constructor(
address addr,
string memory baseURI,
address[] memory mintersWhitelist,
bytes32 rootHash
) public Ownable() ERC721Metadata("Postereum", "PE20") Minter() {
_categoriesContrAddr = addr;
_baseURI = baseURI;
_rootHash = rootHash;
addMinter(msg.sender);
uint256 accountsCount = mintersWhitelist.length;
for (uint256 i = 0; i < accountsCount; i++) {
addMinter(mintersWhitelist[i]);
}
}
modifier onlyMinter() {
require(isMinter(msg.sender) == true, "Caller is not a valid minter");
_;
}
/**
* @dev Gets the total amount of tokens stored by the contract.
* @return uint256 representing the total amount of tokens
*/
function totalSupply() public view returns (uint256) {
return _totalSupply;
}
function setCategoriesContrAddr(address addr) public onlyOwner {
_categoriesContrAddr = addr;
}
/**
* @dev External function to mint a single new token.
* Reverts if the given token ID already exists.
* @param to address the beneficiary that will own the minted token
* @param tokenId uint256 ID of the token to be minted
*/
function mint(address to, uint256 tokenId) external onlyMinter {
require(tokenId>0 && tokenId <501, "Token ID has to be in rage [1,500]");
_mint(to, tokenId);
_totalSupply = _totalSupply.add(1);
}
function mintMultiple(uint256 _tokenIdStart, address[] calldata _owners)
external
onlyMinter
{
uint256 addrcount = _owners.length;
for (uint256 i = 0; i < addrcount; i++) {
_mint(_owners[i], _tokenIdStart + i);
_totalSupply = _totalSupply.add(1);
}
}
/**
* @dev Public function to set calculated root hash.
* @param rootHash bytes32 Calculated root hash of merkle proof tree
*/
function setRootHash(bytes32 rootHash) public onlyOwner
{
_rootHash = rootHash;
}
/**
* @dev Public function to check merkleProof and reedem token to owner.
* @param index uint256- Token index in sorted merkle tree
* @param tokenId uint256 - Token id
* @param merkleProof bytes32[] memory array of a storage proof
*/
function redeem(uint256 index, uint256 tokenId, address owner, bytes32[] memory merkleProof)
public
returns (uint256)
{
bytes32 leaf = keccak256(abi.encodePacked(index, tokenId, owner));
require(MerkleProof.verify(merkleProof, _rootHash, leaf), "Merkle proof verification failed");
_mint(owner, tokenId);
_totalSupply = _totalSupply.add(1);
return tokenId;
}
function tokenURI(uint256 tokenId) public view returns (string memory) {
string memory tokenCategoryId = ITokenCategories(_categoriesContrAddr).getTokenCategory(tokenId);
return string(abi.encodePacked(_baseURI, "/api/v1/category/", tokenCategoryId, "/stamp/", toString(tokenId)));
}
}
pragma solidity ^0.5.0;
import "../GSN/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () internal {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(isOwner(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Returns true if the caller is the current owner.
*/
function isOwner() public view returns (bool) {
return _msgSender() == _owner;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public onlyOwner {
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
*/
function _transferOwnership(address newOwner) internal {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
pragma solidity ^0.5.0;
import "../../GSN/Context.sol";
import "./ERC721.sol";
import "./IERC721Metadata.sol";
import "../../introspection/ERC165.sol";
contract ERC721Metadata is Context, ERC165, ERC721, IERC721Metadata {
// Token name
string private _name;
// Token symbol
string private _symbol;
// Base URI
string private _baseURI;
// Optional mapping for token URIs
mapping(uint256 => string) private _tokenURIs;
/*
* bytes4(keccak256('name()')) == 0x06fdde03
* bytes4(keccak256('symbol()')) == 0x95d89b41
* bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd
*
* => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f
*/
bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;
/**
* @dev Constructor function
*/
constructor (string memory name, string memory symbol) public {
_name = name;
_symbol = symbol;
// register the supported interfaces to conform to ERC721 via ERC165
_registerInterface(_INTERFACE_ID_ERC721_METADATA);
}
/**
* @dev Gets the token name.
* @return string representing the token name
*/
function name() external view returns (string memory) {
return _name;
}
/**
* @dev Gets the token symbol.
* @return string representing the token symbol
*/
function symbol() external view returns (string memory) {
return _symbol;
}
/**
* @dev Returns the URI for a given token ID. May return an empty string.
*
* If the token's URI is non-empty and a base URI was set (via
* {_setBaseURI}), it will be added to the token ID's URI as a prefix.
*
* Reverts if the token ID does not exist.
*/
function tokenURI(uint256 tokenId) external view returns (string memory) {
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
string memory _tokenURI = _tokenURIs[tokenId];
// Even if there is a base URI, it is only appended to non-empty token-specific URIs
if (bytes(_tokenURI).length == 0) {
return "";
} else {
// abi.encodePacked is being used to concatenate strings
return string(abi.encodePacked(_baseURI, _tokenURI));
}
}
/**
* @dev Internal function to set the token URI for a given token.
*
* Reverts if the token ID does not exist.
*
* TIP: if all token IDs share a prefix (e.g. if your URIs look like
* `http://api.myproject.com/token/<id>`), use {_setBaseURI} to store
* it and save gas.
*/
function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal {
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
_tokenURIs[tokenId] = _tokenURI;
}
/**
* @dev Internal function to set the base URI for all token IDs. It is
* automatically added as a prefix to the value returned in {tokenURI}.
*
* _Available since v2.5.0._
*/
function _setBaseURI(string memory baseURI) internal {
_baseURI = baseURI;
}
/**
* @dev Returns the base URI set via {_setBaseURI}. This will be
* automatically added as a preffix in {tokenURI} to each token's URI, when
* they are non-empty.
*
* _Available since v2.5.0._
*/
function baseURI() external view returns (string memory) {
return _baseURI;
}
/**
* @dev Internal function to burn a specific token.
* Reverts if the token does not exist.
* Deprecated, use _burn(uint256) instead.
* @param owner owner of the token to burn
* @param tokenId uint256 ID of the token being burned by the msg.sender
*/
function _burn(address owner, uint256 tokenId) internal {
super._burn(owner, tokenId);
// Clear metadata (if any)
if (bytes(_tokenURIs[tokenId]).length != 0) {
delete _tokenURIs[tokenId];
}
}
}
pragma solidity ^0.5.0;
import "./IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
contract IERC721Metadata is IERC721 {
function name() external view returns (string memory);
function symbol() external view returns (string memory);
function tokenURI(uint256 tokenId) external view returns (string memory);
}
pragma solidity ^0.5.0;
/**
* @dev These functions deal with verification of Merkle trees (hash trees),
*/
library MerkleProof {
/**
* @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
* defined by `root`. For this, a `proof` must be provided, containing
* sibling hashes on the branch from the leaf to the root of the tree. Each
* pair of leaves and each pair of pre-images are assumed to be sorted.
*/
function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
bytes32 computedHash = leaf;
for (uint256 i = 0; i < proof.length; i++) {
bytes32 proofElement = proof[i];
if (computedHash <= proofElement) {
// Hash(current computed hash + current element of the proof)
computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
} else {
// Hash(current element of the proof + current computed hash)
computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
}
}
// Check if the computed hash (root) is equal to the provided root
return computedHash == root;
}
}
pragma solidity ^0.5.5;
import "@openzeppelin/contracts/ownership/Ownable.sol";
contract Minter is Ownable {
mapping (address => bool) minters;
function addMinter(address account) public onlyOwner {
require(account != address(0), "Minter: zero address provided.");
minters[account] = true;
}
function removeMinter(address account) public onlyOwner {
require(account != address(0), "Minter: zero address provided.");
minters[account] = false;
}
function isMinter(address account) public view returns (bool) {
return minters[account];
}
}
pragma solidity ^0.5.5;
contract Utils {
/**
* To String
*
* Converts an unsigned integer to the ASCII string equivalent value
*
* @param _base The unsigned integer to be converted to a string
* @return string The resulting ASCII string value
*/
function toString(uint _base)
internal
pure
returns (string memory) {
bytes memory _tmp = new bytes(32);
uint i;
for(i = 0;_base > 0;i++) {
_tmp[i] = byte(uint8((_base % 10) + 48));
_base /= 10;
}
bytes memory _real = new bytes(i--);
for(uint j = 0; j < _real.length; j++) {
_real[j] = _tmp[i--];
}
return string(_real);
}
}
pragma solidity ^0.5.5;
contract TokenCategories {
function getTokenCategory(uint256 tokenId) public pure returns (string memory) {
if (tokenId > 0 && tokenId <= 500) {
// Token categories for limited stamps sold online
if (tokenId > 0 && tokenId <= 5) {
return "1";
} else if (tokenId > 5 && tokenId <= 25) {
return "2";
} else if (tokenId > 25 && tokenId <= 75) {
return "3";
} else if (tokenId > 75 && tokenId <= 200) {
return "4";
} else if (tokenId > 200 && tokenId <= 500) {
return "5";
}
}
if (tokenId > 500 && tokenId <= 1495) {
return "1";
} else if (tokenId > 1495 && tokenId <= 5475) {
return "2";
} else if (tokenId > 5475 && tokenId <= 15425) {
return "3";
} else if (tokenId > 15425 && tokenId <= 40300) {
return "4";
} else if (tokenId > 40300 && tokenId <= 100000) {
return "5";
}
}
}