Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
import "rainbow-bridge/contracts/eth/nearprover/contracts/ProofDecoder.sol";
import "rainbow-bridge/contracts/eth/nearbridge/contracts/Borsh.sol";
import "rainbow-bridge/contracts/eth/nearbridge/contracts/AdminControlled.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { Bridge, INearProver } from "./Bridge.sol";
contract eNear is ERC20, Bridge, AdminControlled {
uint constant PAUSE_FINALISE_FROM_NEAR = 1 << 0;
uint constant PAUSE_TRANSFER_TO_NEAR = 1 << 1;
event TransferToNearInitiated (
address indexed sender,
uint256 amount,
string accountId
);
event NearToEthTransferFinalised (
uint128 amount,
address indexed recipient
);
struct BridgeResult {
uint128 amount;
address recipient;
}
/// @param _tokenName Name given to the token (can be admin updated)
/// @param _tokenSymbol Symbol given to the token (can be admin updated)
/// @param _nearConnector Near account ID of the near connector bridge
/// @param _prover Address of the prover contract on ETH
/// @param _minBlockAcceptanceHeight The contract will accept proofs from this block onwards
/// @param _admin Address that can make admin changes to the contract
/// @param _pausedFlags Flag settings which controls whether certain methods are paused or active
constructor(
string memory _tokenName,
string memory _tokenSymbol,
bytes memory _nearConnector,
INearProver _prover,
uint64 _minBlockAcceptanceHeight,
address _admin,
uint256 _pausedFlags
) public ERC20(_tokenName, _tokenSymbol) AdminControlled(_admin, _pausedFlags) Bridge(_prover, _nearConnector, _minBlockAcceptanceHeight) {
// Match yocto Near
_setupDecimals(24);
}
function finaliseNearToEthTransfer(bytes memory proofData, uint64 proofBlockHeight)
external pausable (PAUSE_FINALISE_FROM_NEAR) {
ProofDecoder.ExecutionStatus memory status = _parseAndConsumeProof(proofData, proofBlockHeight);
BridgeResult memory result = _decodeBridgeResult(status.successValue);
_mint(result.recipient, result.amount);
emit NearToEthTransferFinalised(result.amount, result.recipient);
}
function transferToNear(uint256 _amount, string memory _nearReceiverAccountId)
external pausable (PAUSE_TRANSFER_TO_NEAR) {
_burn(msg.sender, _amount);
emit TransferToNearInitiated(msg.sender, _amount, _nearReceiverAccountId);
}
function _decodeBridgeResult(bytes memory data) internal pure returns(BridgeResult memory result) {
Borsh.Data memory borshData = Borsh.from(data);
uint8 flag = borshData.decodeU8();
require(flag == 0, "ERR_NOT_WITHDRAW_RESULT");
result.amount = borshData.decodeU128();
bytes20 recipient = borshData.decodeBytes20();
result.recipient = address(uint160(recipient));
}
}
pragma solidity ^0.6;
import "../../nearbridge/contracts/Borsh.sol";
import "../../nearbridge/contracts/NearDecoder.sol";
library ProofDecoder {
using Borsh for Borsh.Data;
using ProofDecoder for Borsh.Data;
using NearDecoder for Borsh.Data;
struct FullOutcomeProof {
ExecutionOutcomeWithIdAndProof outcome_proof;
MerklePath outcome_root_proof; // TODO: now empty array
BlockHeaderLight block_header_lite;
MerklePath block_proof;
}
function decodeFullOutcomeProof(Borsh.Data memory data) internal view returns (FullOutcomeProof memory proof) {
proof.outcome_proof = data.decodeExecutionOutcomeWithIdAndProof();
proof.outcome_root_proof = data.decodeMerklePath();
proof.block_header_lite = data.decodeBlockHeaderLight();
proof.block_proof = data.decodeMerklePath();
}
struct BlockHeaderLight {
bytes32 prev_block_hash;
bytes32 inner_rest_hash;
NearDecoder.BlockHeaderInnerLite inner_lite;
bytes32 hash; // Computable
}
function decodeBlockHeaderLight(Borsh.Data memory data) internal view returns (BlockHeaderLight memory header) {
header.prev_block_hash = data.decodeBytes32();
header.inner_rest_hash = data.decodeBytes32();
header.inner_lite = data.decodeBlockHeaderInnerLite();
header.hash = sha256(
abi.encodePacked(
sha256(abi.encodePacked(header.inner_lite.hash, header.inner_rest_hash)),
header.prev_block_hash
)
);
}
struct ExecutionStatus {
uint8 enumIndex;
bool unknown;
bool failed;
bytes successValue; /// The final action succeeded and returned some value or an empty vec.
bytes32 successReceiptId; /// The final action of the receipt returned a promise or the signed
/// transaction was converted to a receipt. Contains the receipt_id of the generated receipt.
}
function decodeExecutionStatus(Borsh.Data memory data)
internal
pure
returns (ExecutionStatus memory executionStatus)
{
executionStatus.enumIndex = data.decodeU8();
if (executionStatus.enumIndex == 0) {
executionStatus.unknown = true;
} else if (executionStatus.enumIndex == 1) {
//revert("NearDecoder: decodeExecutionStatus failure case not implemented yet");
// Can avoid revert since ExecutionStatus is latest field in all parent structures
executionStatus.failed = true;
} else if (executionStatus.enumIndex == 2) {
executionStatus.successValue = data.decodeBytes();
} else if (executionStatus.enumIndex == 3) {
executionStatus.successReceiptId = data.decodeBytes32();
} else {
revert("NearDecoder: decodeExecutionStatus index out of range");
}
}
struct ExecutionOutcome {
bytes[] logs; /// Logs from this transaction or receipt.
bytes32[] receipt_ids; /// Receipt IDs generated by this transaction or receipt.
uint64 gas_burnt; /// The amount of the gas burnt by the given transaction or receipt.
uint128 tokens_burnt; /// The total number of the tokens burnt by the given transaction or receipt.
bytes executor_id; /// Hash of the transaction or receipt id that produced this outcome.
ExecutionStatus status; /// Execution status. Contains the result in case of successful execution.
bytes32[] merkelization_hashes;
}
function decodeExecutionOutcome(Borsh.Data memory data) internal view returns (ExecutionOutcome memory outcome) {
outcome.logs = new bytes[](data.decodeU32());
for (uint i = 0; i < outcome.logs.length; i++) {
outcome.logs[i] = data.decodeBytes();
}
uint256 start = data.offset;
outcome.receipt_ids = new bytes32[](data.decodeU32());
for (uint i = 0; i < outcome.receipt_ids.length; i++) {
outcome.receipt_ids[i] = data.decodeBytes32();
}
outcome.gas_burnt = data.decodeU64();
outcome.tokens_burnt = data.decodeU128();
outcome.executor_id = data.decodeBytes();
outcome.status = data.decodeExecutionStatus();
uint256 stop = data.offset;
outcome.merkelization_hashes = new bytes32[](1 + outcome.logs.length);
data.offset = start;
outcome.merkelization_hashes[0] = data.peekSha256(stop - start);
data.offset = stop;
for (uint i = 0; i < outcome.logs.length; i++) {
outcome.merkelization_hashes[i + 1] = sha256(outcome.logs[i]);
}
}
struct ExecutionOutcomeWithId {
bytes32 id; /// The transaction hash or the receipt ID.
ExecutionOutcome outcome;
bytes32 hash;
}
function decodeExecutionOutcomeWithId(Borsh.Data memory data)
internal
view
returns (ExecutionOutcomeWithId memory outcome)
{
outcome.id = data.decodeBytes32();
outcome.outcome = data.decodeExecutionOutcome();
uint256 len = 1 + outcome.outcome.merkelization_hashes.length;
outcome.hash = sha256(
abi.encodePacked(
uint8((len >> 0) & 0xFF),
uint8((len >> 8) & 0xFF),
uint8((len >> 16) & 0xFF),
uint8((len >> 24) & 0xFF),
outcome.id,
outcome.outcome.merkelization_hashes
)
);
}
struct MerklePathItem {
bytes32 hash;
uint8 direction; // 0 = left, 1 = right
}
function decodeMerklePathItem(Borsh.Data memory data) internal pure returns (MerklePathItem memory item) {
item.hash = data.decodeBytes32();
item.direction = data.decodeU8();
require(item.direction < 2, "ProofDecoder: MerklePathItem direction should be 0 or 1");
}
struct MerklePath {
MerklePathItem[] items;
}
function decodeMerklePath(Borsh.Data memory data) internal pure returns (MerklePath memory path) {
path.items = new MerklePathItem[](data.decodeU32());
for (uint i = 0; i < path.items.length; i++) {
path.items[i] = data.decodeMerklePathItem();
}
}
struct ExecutionOutcomeWithIdAndProof {
MerklePath proof;
bytes32 block_hash;
ExecutionOutcomeWithId outcome_with_id;
}
function decodeExecutionOutcomeWithIdAndProof(Borsh.Data memory data)
internal
view
returns (ExecutionOutcomeWithIdAndProof memory outcome)
{
outcome.proof = data.decodeMerklePath();
outcome.block_hash = data.decodeBytes32();
outcome.outcome_with_id = data.decodeExecutionOutcomeWithId();
}
}
pragma solidity ^0.6;
import "@openzeppelin/contracts/math/SafeMath.sol";
library Borsh {
using SafeMath for uint256;
struct Data {
uint256 offset;
bytes raw;
}
function from(bytes memory data) internal pure returns (Data memory) {
return Data({offset: 0, raw: data});
}
modifier shift(Data memory data, uint256 size) {
require(data.raw.length >= data.offset + size, "Borsh: Out of range");
_;
data.offset += size;
}
function finished(Data memory data) internal pure returns (bool) {
return data.offset == data.raw.length;
}
function peekKeccak256(Data memory data, uint256 length) internal pure returns (bytes32 res) {
return bytesKeccak256(data.raw, data.offset, length);
}
function bytesKeccak256(
bytes memory ptr,
uint256 offset,
uint256 length
) internal pure returns (bytes32 res) {
// solium-disable-next-line security/no-inline-assembly
assembly {
res := keccak256(add(add(ptr, 32), offset), length)
}
}
function peekSha256(Data memory data, uint256 length) internal view returns (bytes32) {
return bytesSha256(data.raw, data.offset, length);
}
function bytesSha256(
bytes memory ptr,
uint256 offset,
uint256 length
) internal view returns (bytes32) {
bytes32[1] memory result;
// solium-disable-next-line security/no-inline-assembly
assembly {
pop(staticcall(gas(), 0x02, add(add(ptr, 32), offset), length, result, 32))
}
return result[0];
}
function decodeU8(Data memory data) internal pure shift(data, 1) returns (uint8 value) {
value = uint8(data.raw[data.offset]);
}
function decodeI8(Data memory data) internal pure shift(data, 1) returns (int8 value) {
value = int8(data.raw[data.offset]);
}
function decodeU16(Data memory data) internal pure returns (uint16 value) {
value = uint16(decodeU8(data));
value |= (uint16(decodeU8(data)) << 8);
}
function decodeI16(Data memory data) internal pure returns (int16 value) {
value = int16(decodeI8(data));
value |= (int16(decodeI8(data)) << 8);
}
function decodeU32(Data memory data) internal pure returns (uint32 value) {
value = uint32(decodeU16(data));
value |= (uint32(decodeU16(data)) << 16);
}
function decodeI32(Data memory data) internal pure returns (int32 value) {
value = int32(decodeI16(data));
value |= (int32(decodeI16(data)) << 16);
}
function decodeU64(Data memory data) internal pure returns (uint64 value) {
value = uint64(decodeU32(data));
value |= (uint64(decodeU32(data)) << 32);
}
function decodeI64(Data memory data) internal pure returns (int64 value) {
value = int64(decodeI32(data));
value |= (int64(decodeI32(data)) << 32);
}
function decodeU128(Data memory data) internal pure returns (uint128 value) {
value = uint128(decodeU64(data));
value |= (uint128(decodeU64(data)) << 64);
}
function decodeI128(Data memory data) internal pure returns (int128 value) {
value = int128(decodeI64(data));
value |= (int128(decodeI64(data)) << 64);
}
function decodeU256(Data memory data) internal pure returns (uint256 value) {
value = uint256(decodeU128(data));
value |= (uint256(decodeU128(data)) << 128);
}
function decodeI256(Data memory data) internal pure returns (int256 value) {
value = int256(decodeI128(data));
value |= (int256(decodeI128(data)) << 128);
}
function decodeBool(Data memory data) internal pure returns (bool value) {
value = (decodeU8(data) != 0);
}
function decodeBytes(Data memory data) internal pure returns (bytes memory value) {
value = new bytes(decodeU32(data));
for (uint i = 0; i < value.length; i++) {
value[i] = byte(decodeU8(data));
}
}
function decodeBytes32(Data memory data) internal pure shift(data, 32) returns (bytes32 value) {
bytes memory raw = data.raw;
uint256 offset = data.offset;
// solium-disable-next-line security/no-inline-assembly
assembly {
value := mload(add(add(raw, 32), offset))
}
}
function decodeBytes20(Data memory data) internal pure returns (bytes20 value) {
for (uint i = 0; i < 20; i++) {
value |= bytes20(byte(decodeU8(data)) & 0xFF) >> (i * 8);
}
}
// Public key
struct SECP256K1PublicKey {
uint256 x;
uint256 y;
}
function decodeSECP256K1PublicKey(Borsh.Data memory data) internal pure returns (SECP256K1PublicKey memory key) {
key.x = decodeU256(data);
key.y = decodeU256(data);
}
struct ED25519PublicKey {
bytes32 xy;
}
function decodeED25519PublicKey(Borsh.Data memory data) internal pure returns (ED25519PublicKey memory key) {
key.xy = decodeBytes32(data);
}
// Signature
struct SECP256K1Signature {
bytes32 r;
bytes32 s;
uint8 v;
}
function decodeSECP256K1Signature(Borsh.Data memory data) internal pure returns (SECP256K1Signature memory sig) {
sig.r = decodeBytes32(data);
sig.s = decodeBytes32(data);
sig.v = decodeU8(data);
}
struct ED25519Signature {
bytes32[2] rs;
}
function decodeED25519Signature(Borsh.Data memory data) internal pure returns (ED25519Signature memory sig) {
sig.rs[0] = decodeBytes32(data);
sig.rs[1] = decodeBytes32(data);
}
}
pragma solidity ^0.6;
contract AdminControlled {
address public admin;
uint public paused;
constructor(address _admin, uint flags) public {
admin = _admin;
// Add the possibility to set pause flags on the initialization
paused = flags;
}
modifier onlyAdmin {
require(msg.sender == admin);
_;
}
modifier pausable(uint flag) {
require((paused & flag) == 0 || msg.sender == admin);
_;
}
function adminPause(uint flags) public onlyAdmin {
paused = flags;
}
function adminSstore(uint key, uint value) public onlyAdmin {
assembly {
sstore(key, value)
}
}
function adminSendEth(address payable destination, uint amount) public onlyAdmin {
destination.transfer(amount);
}
function adminReceiveEth() public payable onlyAdmin {}
function adminDelegatecall(address target, bytes memory data) public payable onlyAdmin returns (bytes memory) {
(bool success, bytes memory rdata) = target.delegatecall(data);
require(success);
return rdata;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../../utils/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.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}.
*/
contract ERC20 is Context, IERC20 {
using SafeMath for uint256;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
uint8 private _decimals;
/**
* @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_) public {
_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(_msgSender(), 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(_msgSender(), 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, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
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(_msgSender(), spender, _allowances[_msgSender()][spender].add(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(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
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].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(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.add(amount);
_balances[account] = _balances[account].add(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].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(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 0.6.12;
import "rainbow-bridge/contracts/eth/nearprover/contracts/INearProver.sol";
import "rainbow-bridge/contracts/eth/nearprover/contracts/ProofDecoder.sol";
import "rainbow-bridge/contracts/eth/nearbridge/contracts/Borsh.sol";
contract Bridge {
using Borsh for Borsh.Data;
using ProofDecoder for Borsh.Data;
event ConsumedProof(bytes32 indexed _receiptId);
INearProver public prover;
bytes public nearConnector;
/// Proofs from blocks that are below the acceptance height will be rejected.
// If `minBlockAcceptanceHeight` value is zero - proofs from block with any height are accepted.
uint64 public minBlockAcceptanceHeight;
// OutcomeRecieptId -> Used
mapping(bytes32 => bool) public usedProofs;
constructor(INearProver _prover, bytes memory _nearConnector, uint64 _minBlockAcceptanceHeight) public {
prover = _prover;
nearConnector = _nearConnector;
minBlockAcceptanceHeight = _minBlockAcceptanceHeight;
}
/// Parses the provided proof and consumes it if it's not already used.
/// The consumed event cannot be reused for future calls.
function _parseAndConsumeProof(bytes memory proofData, uint64 proofBlockHeight)
internal
returns (ProofDecoder.ExecutionStatus memory result)
{
require(prover.proveOutcome(proofData, proofBlockHeight), "Proof should be valid");
// Unpack the proof and extract the execution outcome.
Borsh.Data memory borshData = Borsh.from(proofData);
ProofDecoder.FullOutcomeProof memory fullOutcomeProof = borshData.decodeFullOutcomeProof();
require(
fullOutcomeProof.block_header_lite.inner_lite.height >= minBlockAcceptanceHeight,
"Proof is from the ancient block"
);
require(borshData.finished(), "Argument should be exact borsh serialization");
bytes32 receiptId = fullOutcomeProof.outcome_proof.outcome_with_id.outcome.receipt_ids[0];
require(!usedProofs[receiptId], "The burn event proof cannot be reused");
usedProofs[receiptId] = true;
require(keccak256(fullOutcomeProof.outcome_proof.outcome_with_id.outcome.executor_id)
== keccak256(nearConnector),
"Can only unlock tokens from the linked proof producer on Near blockchain");
result = fullOutcomeProof.outcome_proof.outcome_with_id.outcome.status;
require(!result.failed, "Cannot use failed execution outcome for unlocking the tokens");
require(!result.unknown, "Cannot use unknown execution outcome for unlocking the tokens");
emit ConsumedProof(receiptId);
}
}
pragma solidity ^0.6;
import "@openzeppelin/contracts/math/SafeMath.sol";
import "./Borsh.sol";
library NearDecoder {
using Borsh for Borsh.Data;
using NearDecoder for Borsh.Data;
struct PublicKey {
uint8 enumIndex;
Borsh.ED25519PublicKey ed25519;
Borsh.SECP256K1PublicKey secp256k1;
}
function decodePublicKey(Borsh.Data memory data) internal pure returns (PublicKey memory key) {
key.enumIndex = data.decodeU8();
if (key.enumIndex == 0) {
key.ed25519 = data.decodeED25519PublicKey();
} else if (key.enumIndex == 1) {
key.secp256k1 = data.decodeSECP256K1PublicKey();
} else {
revert("NearBridge: Only ED25519 and SECP256K1 public keys are supported");
}
}
struct ValidatorStake {
string account_id;
PublicKey public_key;
uint128 stake;
}
function decodeValidatorStake(Borsh.Data memory data) internal pure returns (ValidatorStake memory validatorStake) {
validatorStake.account_id = string(data.decodeBytes());
validatorStake.public_key = data.decodePublicKey();
validatorStake.stake = data.decodeU128();
}
struct OptionalValidatorStakes {
bool none;
ValidatorStake[] validatorStakes;
bytes32 hash; // Additional computable element
}
function decodeOptionalValidatorStakes(Borsh.Data memory data)
internal
view
returns (OptionalValidatorStakes memory stakes)
{
stakes.none = (data.decodeU8() == 0);
if (!stakes.none) {
uint256 start = data.offset;
stakes.validatorStakes = new ValidatorStake[](data.decodeU32());
for (uint i = 0; i < stakes.validatorStakes.length; i++) {
stakes.validatorStakes[i] = data.decodeValidatorStake();
}
uint256 stop = data.offset;
data.offset = start;
stakes.hash = data.peekSha256(stop - start);
data.offset = stop;
}
}
struct Signature {
uint8 enumIndex;
Borsh.ED25519Signature ed25519;
Borsh.SECP256K1Signature secp256k1;
}
function decodeSignature(Borsh.Data memory data) internal pure returns (Signature memory sig) {
sig.enumIndex = data.decodeU8();
if (sig.enumIndex == 0) {
sig.ed25519 = data.decodeED25519Signature();
} else if (sig.enumIndex == 1) {
sig.secp256k1 = data.decodeSECP256K1Signature();
} else {
revert("NearBridge: Only ED25519 and SECP256K1 signatures are supported");
}
}
struct OptionalSignature {
bool none;
Signature signature;
}
function decodeOptionalSignature(Borsh.Data memory data) internal pure returns (OptionalSignature memory sig) {
sig.none = (data.decodeU8() == 0);
if (!sig.none) {
sig.signature = data.decodeSignature();
}
}
struct LightClientBlock {
bytes32 prev_block_hash;
bytes32 next_block_inner_hash;
BlockHeaderInnerLite inner_lite;
bytes32 inner_rest_hash;
OptionalValidatorStakes next_bps;
OptionalSignature[] approvals_after_next;
bytes32 hash;
bytes32 next_hash;
}
struct InitialValidators {
ValidatorStake[] validator_stakes;
}
function decodeInitialValidators(Borsh.Data memory data)
internal
view
returns (InitialValidators memory validators)
{
validators.validator_stakes = new ValidatorStake[](data.decodeU32());
for (uint i = 0; i < validators.validator_stakes.length; i++) {
validators.validator_stakes[i] = data.decodeValidatorStake();
}
}
function decodeLightClientBlock(Borsh.Data memory data) internal view returns (LightClientBlock memory header) {
header.prev_block_hash = data.decodeBytes32();
header.next_block_inner_hash = data.decodeBytes32();
header.inner_lite = data.decodeBlockHeaderInnerLite();
header.inner_rest_hash = data.decodeBytes32();
header.next_bps = data.decodeOptionalValidatorStakes();
header.approvals_after_next = new OptionalSignature[](data.decodeU32());
for (uint i = 0; i < header.approvals_after_next.length; i++) {
header.approvals_after_next[i] = data.decodeOptionalSignature();
}
header.hash = sha256(
abi.encodePacked(
sha256(abi.encodePacked(header.inner_lite.hash, header.inner_rest_hash)),
header.prev_block_hash
)
);
header.next_hash = sha256(abi.encodePacked(header.next_block_inner_hash, header.hash));
}
struct BlockHeaderInnerLite {
uint64 height; /// Height of this block since the genesis block (height 0).
bytes32 epoch_id; /// Epoch start hash of this block's epoch. Used for retrieving validator information
bytes32 next_epoch_id;
bytes32 prev_state_root; /// Root hash of the state at the previous block.
bytes32 outcome_root; /// Root of the outcomes of transactions and receipts.
uint64 timestamp; /// Timestamp at which the block was built.
bytes32 next_bp_hash; /// Hash of the next epoch block producers set
bytes32 block_merkle_root;
bytes32 hash; // Additional computable element
}
function decodeBlockHeaderInnerLite(Borsh.Data memory data)
internal
view
returns (BlockHeaderInnerLite memory header)
{
header.hash = data.peekSha256(208);
header.height = data.decodeU64();
header.epoch_id = data.decodeBytes32();
header.next_epoch_id = data.decodeBytes32();
header.prev_state_root = data.decodeBytes32();
header.outcome_root = data.decodeBytes32();
header.timestamp = data.decodeU64();
header.next_bp_hash = data.decodeBytes32();
header.block_merkle_root = data.decodeBytes32();
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @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, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b > a) return (false, 0);
return (true, a - b);
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, 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 (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a / b);
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a % b);
}
/**
* @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) {
require(b <= a, "SafeMath: subtraction overflow");
return a - b;
}
/**
* @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) {
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, reverting 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) {
require(b > 0, "SafeMath: division by zero");
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting 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) {
require(b > 0, "SafeMath: modulo by zero");
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
return a - b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryDiv}.
*
* 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, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* 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, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
return a % b;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/*
* @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.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address payable) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @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);
}
pragma solidity ^0.6;
interface INearProver {
function proveOutcome(bytes calldata proofData, uint64 blockHeight) external view returns (bool);
}