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EtherDelta

Token
0x8d12a197cb00...5ce2a5cc6819
Spurious DragonContract #30KSource VerifiedEdit this contract
Deployed February 10, 2017 (9 years ago)Block 3,154,196

The first major decentralized exchange on Ethereum, deployed February 9, 2017. Used off-chain signed orders with on-chain settlement to enable trustless ERC-20

Key Facts

Deployment Block
3,154,196
Deployment Date
Feb 10, 2017, 03:50 AM
Code Size
6.5 KB
Gas at Deploy
1,901,944

Description

EtherDelta was the first widely-used decentralized exchange (DEX) on Ethereum, deployed at block 3,154,196 on February 9, 2017. It implemented a smart contract-based order book system that allowed users to trade ERC-20 tokens without trusting a centralized intermediary to custody their funds.

The contract architecture used a deposit/withdraw model: users deposited ETH or ERC-20 tokens into the EtherDelta smart contract, then signed orders off-chain. When two orders matched, a trade could be executed on-chain by calling the trade() function with both signatures. This hybrid approach — off-chain order relay with on-chain settlement — reduced gas costs while maintaining trustlessness. The contract also supported availableVolume() queries and included admin functions for fee adjustment.

Written in Solidity 0.4.9 with SafeMath protections, the contract source code was open-sourced on GitHub (github.com/etherdelta/smart_contract). The fee model charged a small percentage on trades, configurable by the admin address.

EtherDelta became the dominant venue for trading ERC-20 tokens during the 2017 ICO boom. For many newly-launched tokens, EtherDelta was the first — and sometimes only — exchange where they could be traded. Its simple web interface at etherdelta.com allowed anyone with MetaMask to trade tokens that had not yet been listed on centralized exchanges.

In December 2017, the etherdelta.com domain was hijacked via a DNS attack. Attackers redirected users to a phishing version of the site that drained funds from visitors who approved transactions. The smart contract itself was not compromised — the attack exploited the off-chain frontend.

In November 2018, the SEC charged EtherDelta's founder, Zachary Coburn, with operating an unregistered securities exchange (SEC Release No. 2018-258). Coburn settled the charges, paying a total of approximately $388,000 in disgorgement, penalties, and interest. This was the SEC's first enforcement action against a decentralized exchange operator.

Source Verified

Etherscan verified

Heuristic Analysis

The following characteristics were detected through bytecode analysis and may not be accurate.

Detected Type: Token
Has ERC-20-like patterns

Spurious Dragon Era

Continued DoS protection. State trie clearing.

Block span: 2,675,0004,369,999
November 22, 2016October 16, 2017

Bytecode Overview

Opcodes6,613
Unique Opcodes239
Jump Instructions354
Storage Operations106

Verified Source Available

Source verified on Etherscan.

Show source code (Solidity)
pragma solidity ^0.4.9;

contract SafeMath {
  function safeMul(uint a, uint b) internal returns (uint) {
    uint c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function safeSub(uint a, uint b) internal returns (uint) {
    assert(b <= a);
    return a - b;
  }

  function safeAdd(uint a, uint b) internal returns (uint) {
    uint c = a + b;
    assert(c>=a && c>=b);
    return c;
  }

  function assert(bool assertion) internal {
    if (!assertion) throw;
  }
}

contract Token {
  /// @return total amount of tokens
  function totalSupply() constant returns (uint256 supply) {}

  /// @param _owner The address from which the balance will be retrieved
  /// @return The balance
  function balanceOf(address _owner) constant returns (uint256 balance) {}

  /// @notice send `_value` token to `_to` from `msg.sender`
  /// @param _to The address of the recipient
  /// @param _value The amount of token to be transferred
  /// @return Whether the transfer was successful or not
  function transfer(address _to, uint256 _value) returns (bool success) {}

  /// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
  /// @param _from The address of the sender
  /// @param _to The address of the recipient
  /// @param _value The amount of token to be transferred
  /// @return Whether the transfer was successful or not
  function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {}

  /// @notice `msg.sender` approves `_addr` to spend `_value` tokens
  /// @param _spender The address of the account able to transfer the tokens
  /// @param _value The amount of wei to be approved for transfer
  /// @return Whether the approval was successful or not
  function approve(address _spender, uint256 _value) returns (bool success) {}

  /// @param _owner The address of the account owning tokens
  /// @param _spender The address of the account able to transfer the tokens
  /// @return Amount of remaining tokens allowed to spent
  function allowance(address _owner, address _spender) constant returns (uint256 remaining) {}

  event Transfer(address indexed _from, address indexed _to, uint256 _value);
  event Approval(address indexed _owner, address indexed _spender, uint256 _value);

  uint public decimals;
  string public name;
}

contract StandardToken is Token {

  function transfer(address _to, uint256 _value) returns (bool success) {
    //Default assumes totalSupply can't be over max (2^256 - 1).
    //If your token leaves out totalSupply and can issue more tokens as time goes on, you need to check if it doesn't wrap.
    //Replace the if with this one instead.
    if (balances[msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
    //if (balances[msg.sender] >= _value && _value > 0) {
      balances[msg.sender] -= _value;
      balances[_to] += _value;
      Transfer(msg.sender, _to, _value);
      return true;
    } else { return false; }
  }

  function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
    //same as above. Replace this line with the following if you want to protect against wrapping uints.
    if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
    //if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
      balances[_to] += _value;
      balances[_from] -= _value;
      allowed[_from][msg.sender] -= _value;
      Transfer(_from, _to, _value);
      return true;
    } else { return false; }
  }

  function balanceOf(address _owner) constant returns (uint256 balance) {
    return balances[_owner];
  }

  function approve(address _spender, uint256 _value) returns (bool success) {
    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
  }

  function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
    return allowed[_owner][_spender];
  }

  mapping(address => uint256) balances;

  mapping (address => mapping (address => uint256)) allowed;

  uint256 public totalSupply;
}

contract ReserveToken is StandardToken, SafeMath {
  address public minter;
  function ReserveToken() {
    minter = msg.sender;
  }
  function create(address account, uint amount) {
    if (msg.sender != minter) throw;
    balances[account] = safeAdd(balances[account], amount);
    totalSupply = safeAdd(totalSupply, amount);
  }
  function destroy(address account, uint amount) {
    if (msg.sender != minter) throw;
    if (balances[account] < amount) throw;
    balances[account] = safeSub(balances[account], amount);
    totalSupply = safeSub(totalSupply, amount);
  }
}

contract AccountLevels {
  //given a user, returns an account level
  //0 = regular user (pays take fee and make fee)
  //1 = market maker silver (pays take fee, no make fee, gets rebate)
  //2 = market maker gold (pays take fee, no make fee, gets entire counterparty's take fee as rebate)
  function accountLevel(address user) constant returns(uint) {}
}

contract AccountLevelsTest is AccountLevels {
  mapping (address => uint) public accountLevels;

  function setAccountLevel(address user, uint level) {
    accountLevels[user] = level;
  }

  function accountLevel(address user) constant returns(uint) {
    return accountLevels[user];
  }
}

contract EtherDelta is SafeMath {
  address public admin; //the admin address
  address public feeAccount; //the account that will receive fees
  address public accountLevelsAddr; //the address of the AccountLevels contract
  uint public feeMake; //percentage times (1 ether)
  uint public feeTake; //percentage times (1 ether)
  uint public feeRebate; //percentage times (1 ether)
  mapping (address => mapping (address => uint)) public tokens; //mapping of token addresses to mapping of account balances (token=0 means Ether)
  mapping (address => mapping (bytes32 => bool)) public orders; //mapping of user accounts to mapping of order hashes to booleans (true = submitted by user, equivalent to offchain signature)
  mapping (address => mapping (bytes32 => uint)) public orderFills; //mapping of user accounts to mapping of order hashes to uints (amount of order that has been filled)

  event Order(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user);
  event Cancel(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s);
  event Trade(address tokenGet, uint amountGet, address tokenGive, uint amountGive, address get, address give);
  event Deposit(address token, address user, uint amount, uint balance);
  event Withdraw(address token, address user, uint amount, uint balance);

  function EtherDelta(address admin_, address feeAccount_, address accountLevelsAddr_, uint feeMake_, uint feeTake_, uint feeRebate_) {
    admin = admin_;
    feeAccount = feeAccount_;
    accountLevelsAddr = accountLevelsAddr_;
    feeMake = feeMake_;
    feeTake = feeTake_;
    feeRebate = feeRebate_;
  }

  function() {
    throw;
  }

  function changeAdmin(address admin_) {
    if (msg.sender != admin) throw;
    admin = admin_;
  }

  function changeAccountLevelsAddr(address accountLevelsAddr_) {
    if (msg.sender != admin) throw;
    accountLevelsAddr = accountLevelsAddr_;
  }

  function changeFeeAccount(address feeAccount_) {
    if (msg.sender != admin) throw;
    feeAccount = feeAccount_;
  }

  function changeFeeMake(uint feeMake_) {
    if (msg.sender != admin) throw;
    if (feeMake_ > feeMake) throw;
    feeMake = feeMake_;
  }

  function changeFeeTake(uint feeTake_) {
    if (msg.sender != admin) throw;
    if (feeTake_ > feeTake || feeTake_ < feeRebate) throw;
    feeTake = feeTake_;
  }

  function changeFeeRebate(uint feeRebate_) {
    if (msg.sender != admin) throw;
    if (feeRebate_ < feeRebate || feeRebate_ > feeTake) throw;
    feeRebate = feeRebate_;
  }

  function deposit() payable {
    tokens[0][msg.sender] = safeAdd(tokens[0][msg.sender], msg.value);
    Deposit(0, msg.sender, msg.value, tokens[0][msg.sender]);
  }

  function withdraw(uint amount) {
    if (tokens[0][msg.sender] < amount) throw;
    tokens[0][msg.sender] = safeSub(tokens[0][msg.sender], amount);
    if (!msg.sender.call.value(amount)()) throw;
    Withdraw(0, msg.sender, amount, tokens[0][msg.sender]);
  }

  function depositToken(address token, uint amount) {
    //remember to call Token(address).approve(this, amount) or this contract will not be able to do the transfer on your behalf.
    if (token==0) throw;
    if (!Token(token).transferFrom(msg.sender, this, amount)) throw;
    tokens[token][msg.sender] = safeAdd(tokens[token][msg.sender], amount);
    Deposit(token, msg.sender, amount, tokens[token][msg.sender]);
  }

  function withdrawToken(address token, uint amount) {
    if (token==0) throw;
    if (tokens[token][msg.sender] < amount) throw;
    tokens[token][msg.sender] = safeSub(tokens[token][msg.sender], amount);
    if (!Token(token).transfer(msg.sender, amount)) throw;
    Withdraw(token, msg.sender, amount, tokens[token][msg.sender]);
  }

  function balanceOf(address token, address user) constant returns (uint) {
    return tokens[token][user];
  }

  function order(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce) {
    bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
    orders[msg.sender][hash] = true;
    Order(tokenGet, amountGet, tokenGive, amountGive, expires, nonce, msg.sender);
  }

  function trade(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s, uint amount) {
    //amount is in amountGet terms
    bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
    if (!(
      (orders[user][hash] || ecrecover(sha3("\x19Ethereum Signed Message:\n32", hash),v,r,s) == user) &&
      block.number <= expires &&
      safeAdd(orderFills[user][hash], amount) <= amountGet
    )) throw;
    tradeBalances(tokenGet, amountGet, tokenGive, amountGive, user, amount);
    orderFills[user][hash] = safeAdd(orderFills[user][hash], amount);
    Trade(tokenGet, amount, tokenGive, amountGive * amount / amountGet, user, msg.sender);
  }

  function tradeBalances(address tokenGet, uint amountGet, address tokenGive, uint amountGive, address user, uint amount) private {
    uint feeMakeXfer = safeMul(amount, feeMake) / (1 ether);
    uint feeTakeXfer = safeMul(amount, feeTake) / (1 ether);
    uint feeRebateXfer = 0;
    if (accountLevelsAddr != 0x0) {
      uint accountLevel = AccountLevels(accountLevelsAddr).accountLevel(user);
      if (accountLevel==1) feeRebateXfer = safeMul(amount, feeRebate) / (1 ether);
      if (accountLevel==2) feeRebateXfer = feeTakeXfer;
    }
    tokens[tokenGet][msg.sender] = safeSub(tokens[tokenGet][msg.sender], safeAdd(amount, feeTakeXfer));
    tokens[tokenGet][user] = safeAdd(tokens[tokenGet][user], safeSub(safeAdd(amount, feeRebateXfer), feeMakeXfer));
    tokens[tokenGet][feeAccount] = safeAdd(tokens[tokenGet][feeAccount], safeSub(safeAdd(feeMakeXfer, feeTakeXfer), feeRebateXfer));
    tokens[tokenGive][user] = safeSub(tokens[tokenGive][user], safeMul(amountGive, amount) / amountGet);
    tokens[tokenGive][msg.sender] = safeAdd(tokens[tokenGive][msg.sender], safeMul(amountGive, amount) / amountGet);
  }

  function testTrade(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s, uint amount, address sender) constant returns(bool) {
    if (!(
      tokens[tokenGet][sender] >= amount &&
      availableVolume(tokenGet, amountGet, tokenGive, amountGive, expires, nonce, user, v, r, s) >= amount
    )) return false;
    return true;
  }

  function availableVolume(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s) constant returns(uint) {
    bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
    if (!(
      (orders[user][hash] || ecrecover(sha3("\x19Ethereum Signed Message:\n32", hash),v,r,s) == user) &&
      block.number <= expires
    )) return 0;
    uint available1 = safeSub(amountGet, orderFills[user][hash]);
    uint available2 = safeMul(tokens[tokenGive][user], amountGet) / amountGive;
    if (available1<available2) return available1;
    return available2;
  }

  function amountFilled(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, address user, uint8 v, bytes32 r, bytes32 s) constant returns(uint) {
    bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
    return orderFills[user][hash];
  }

  function cancelOrder(address tokenGet, uint amountGet, address tokenGive, uint amountGive, uint expires, uint nonce, uint8 v, bytes32 r, bytes32 s) {
    bytes32 hash = sha256(this, tokenGet, amountGet, tokenGive, amountGive, expires, nonce);
    if (!(orders[msg.sender][hash] || ecrecover(sha3("\x19Ethereum Signed Message:\n32", hash),v,r,s) == msg.sender)) throw;
    orderFills[msg.sender][hash] = amountGet;
    Cancel(tokenGet, amountGet, tokenGive, amountGive, expires, nonce, msg.sender, v, r, s);
  }
}

External Links

EtherDelta - Ethereum History