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Crowdsale

Utility
0x9af2b1687601...06b99c3a4858
HomesteadSource VerifiedEdit this contract
Deployed March 17, 2016 (10 years ago)Block 1,168,178

The ethereum.org crowdsale tutorial: contributions run to a deadline against a goal, pay out a separate reward token, and are refunded if the goal is missed.

Homestead EraVerified Source

Historical Significance

The ethereum.org crowdsale tutorial was the worked example most token sales of the period started from, and its shape, a deadline, a goal, a fixed price and a refund if the goal is missed, is the one the sales of the following two years repeated. The flaws are instructive too: unchecked send() calls and an unbounded refund loop are exactly the failures auditors spent the next years writing up.

Context

By 2016 the ethereum.org tutorial had been rewritten around the transfer interface that ERC-20 was standardising, and its crowdsale took its funding goal and token price in whole ether rather than wei. Copies of it went on chain steadily through the year, most of them as trials with short deadlines and small goals rather than as real sales.

Key Facts
Deployment Block
1,168,178
Deployment Date
Mar 17, 2016, 07:52 PM
Code Size
1.3 KB

Description

The crowdfunding contract from the ethereum.org tutorial. Its constructor fixes the beneficiary, the funding goal in whole ether, the length of the campaign in minutes, the price of one reward token in whole ether, and the token contract that pays contributors. None of them can be changed afterwards.

Contributions arrive through the fallback function, which records the sender and amount in a public funders array and calls transfer on the reward token for the amount divided by the price. After the deadline anyone may call checkGoalReached(): if the goal was met the balance is sent to the beneficiary, otherwise the contract loops over the funders and refunds them, and in both cases whatever remains is swept to the beneficiary and the sale is marked closed.

The reward tokens must already be held by this contract when the sale opens, and nothing checks that they are. The refund loop is unbounded and no send() return value is checked, so a campaign with many contributors can leave funds it cannot pay out.

This one pays 0xde7d6c76260456d7519f8c03bc05871840a7c2c8 on success. It was opened with a goal of 3 ether, a window of 30 minutes, and a price of 1 ether for one token, handing out the token at 0x0be6d73fe3899575dd54ded96567b09f73d9cc2f.

Heuristic Analysis

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

Detected Type: Utility

Bytecode Overview

Opcodes1,313
Unique Opcodes132
Jump Instructions51
Storage Operations41

External Links

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