Hardfork Meta: DAO Fork
EIP-779: Hardfork Meta: DAO Fork is a document that outlines the changes made during the DAO Fork hard fork in the Ethereum blockchain. Unlike other hard forks, the DAO Fork did not change the protocol itself, but rather was an "irregular state change" that transferred ether balances from a list of accounts (known as "child DAO" contracts) into a specified account (the "WithdrawDAO" contract). This was done in response to a hack that occurred in June 2016, where a vulnerability in the DAO smart contract allowed an attacker to siphon off a large amount of ether.
The DAO Fork was activated at block 1,920,000 on the Ethereum mainnet, and involved transferring all ether throughout the accounts in the specified list to the WithdrawDAO contract. This contract was created from Solidity code and deployed on the mainnet in block 1,883,496. The deployment code and resulting runtime bytecode are also included in the EIP-779 document.
Blocks with block numbers in the range of 1,920,000 to 1,920,009 were required to have a specific hex-encoded ASCII string in the extraData field of the block to indicate that they were part of the DAO Fork.
Overall, the DAO Fork was a controversial decision that divided the Ethereum community. Some argued that it was necessary to prevent further damage from the hack, while others believed that it went against the principles of decentralization and immutability that underpin the blockchain. Regardless of one's opinion on the matter, the DAO Fork remains a significant event in the history of Ethereum and blockchain technology as a whole.
Video
Original
Abstract
This documents the changes included in the hard fork named "DAO Fork". Unlike other hard forks, the DAO Fork did not change the protocol; all EVM opcodes, transaction format, block structure, and so on remained the same. Rather, the DAO Fork was an "irregular state change" that transferred ether balances from a list of accounts ("child DAO" contracts) into a specified account (the "WithdrawDAO" contract).
Specification
- Codename: DAO Fork
- Activation:
- Block == 1,920,000 on Mainnet
See references [1] and [2] for the original, full specification. It is summarized here for convenience.
At block 1880000, the following accounts are encoded into a list L
:
- The DAO (
0xbb9bc244d798123fde783fcc1c72d3bb8c189413
) - its extraBalance (
0x807640a13483f8ac783c557fcdf27be11ea4ac7a
) - all children of the DAO creator (
0x4a574510c7014e4ae985403536074abe582adfc8
) - and the extraBalance of each child
Reference list L
0xd4fe7bc31cedb7bfb8a345f31e668033056b2728,
0xb3fb0e5aba0e20e5c49d252dfd30e102b171a425,
0x2c19c7f9ae8b751e37aeb2d93a699722395ae18f,
0xecd135fa4f61a655311e86238c92adcd779555d2,
0x1975bd06d486162d5dc297798dfc41edd5d160a7,
0xa3acf3a1e16b1d7c315e23510fdd7847b48234f6,
0x319f70bab6845585f412ec7724b744fec6095c85,
0x06706dd3f2c9abf0a21ddcc6941d9b86f0596936,
0x5c8536898fbb74fc7445814902fd08422eac56d0,
0x6966ab0d485353095148a2155858910e0965b6f9,
0x779543a0491a837ca36ce8c635d6154e3c4911a6,
0x2a5ed960395e2a49b1c758cef4aa15213cfd874c,
0x5c6e67ccd5849c0d29219c4f95f1a7a93b3f5dc5,
0x9c50426be05db97f5d64fc54bf89eff947f0a321,
0x200450f06520bdd6c527622a273333384d870efb,
0xbe8539bfe837b67d1282b2b1d61c3f723966f049,
0x6b0c4d41ba9ab8d8cfb5d379c69a612f2ced8ecb,
0xf1385fb24aad0cd7432824085e42aff90886fef5,
0xd1ac8b1ef1b69ff51d1d401a476e7e612414f091,
0x8163e7fb499e90f8544ea62bbf80d21cd26d9efd,
0x51e0ddd9998364a2eb38588679f0d2c42653e4a6,
0x627a0a960c079c21c34f7612d5d230e01b4ad4c7,
0xf0b1aa0eb660754448a7937c022e30aa692fe0c5,
0x24c4d950dfd4dd1902bbed3508144a54542bba94,
0x9f27daea7aca0aa0446220b98d028715e3bc803d,
0xa5dc5acd6a7968a4554d89d65e59b7fd3bff0f90,
0xd9aef3a1e38a39c16b31d1ace71bca8ef58d315b,
0x63ed5a272de2f6d968408b4acb9024f4cc208ebf,
0x6f6704e5a10332af6672e50b3d9754dc460dfa4d,
0x77ca7b50b6cd7e2f3fa008e24ab793fd56cb15f6,
0x492ea3bb0f3315521c31f273e565b868fc090f17,
0x0ff30d6de14a8224aa97b78aea5388d1c51c1f00,
0x9ea779f907f0b315b364b0cfc39a0fde5b02a416,
0xceaeb481747ca6c540a000c1f3641f8cef161fa7,
0xcc34673c6c40e791051898567a1222daf90be287,
0x579a80d909f346fbfb1189493f521d7f48d52238,
0xe308bd1ac5fda103967359b2712dd89deffb7973,
0x4cb31628079fb14e4bc3cd5e30c2f7489b00960c,
0xac1ecab32727358dba8962a0f3b261731aad9723,
0x4fd6ace747f06ece9c49699c7cabc62d02211f75,
0x440c59b325d2997a134c2c7c60a8c61611212bad,
0x4486a3d68fac6967006d7a517b889fd3f98c102b,
0x9c15b54878ba618f494b38f0ae7443db6af648ba,
0x27b137a85656544b1ccb5a0f2e561a5703c6a68f,
0x21c7fdb9ed8d291d79ffd82eb2c4356ec0d81241,
0x23b75c2f6791eef49c69684db4c6c1f93bf49a50,
0x1ca6abd14d30affe533b24d7a21bff4c2d5e1f3b,
0xb9637156d330c0d605a791f1c31ba5890582fe1c,
0x6131c42fa982e56929107413a9d526fd99405560,
0x1591fc0f688c81fbeb17f5426a162a7024d430c2,
0x542a9515200d14b68e934e9830d91645a980dd7a,
0xc4bbd073882dd2add2424cf47d35213405b01324,
0x782495b7b3355efb2833d56ecb34dc22ad7dfcc4,
0x58b95c9a9d5d26825e70a82b6adb139d3fd829eb,
0x3ba4d81db016dc2890c81f3acec2454bff5aada5,
0xb52042c8ca3f8aa246fa79c3feaa3d959347c0ab,
0xe4ae1efdfc53b73893af49113d8694a057b9c0d1,
0x3c02a7bc0391e86d91b7d144e61c2c01a25a79c5,
0x0737a6b837f97f46ebade41b9bc3e1c509c85c53,
0x97f43a37f595ab5dd318fb46e7a155eae057317a,
0x52c5317c848ba20c7504cb2c8052abd1fde29d03,
0x4863226780fe7c0356454236d3b1c8792785748d,
0x5d2b2e6fcbe3b11d26b525e085ff818dae332479,
0x5f9f3392e9f62f63b8eac0beb55541fc8627f42c,
0x057b56736d32b86616a10f619859c6cd6f59092a,
0x9aa008f65de0b923a2a4f02012ad034a5e2e2192,
0x304a554a310c7e546dfe434669c62820b7d83490,
0x914d1b8b43e92723e64fd0a06f5bdb8dd9b10c79,
0x4deb0033bb26bc534b197e61d19e0733e5679784,
0x07f5c1e1bc2c93e0402f23341973a0e043f7bf8a,
0x35a051a0010aba705c9008d7a7eff6fb88f6ea7b,
0x4fa802324e929786dbda3b8820dc7834e9134a2a,
0x9da397b9e80755301a3b32173283a91c0ef6c87e,
0x8d9edb3054ce5c5774a420ac37ebae0ac02343c6,
0x0101f3be8ebb4bbd39a2e3b9a3639d4259832fd9,
0x5dc28b15dffed94048d73806ce4b7a4612a1d48f,
0xbcf899e6c7d9d5a215ab1e3444c86806fa854c76,
0x12e626b0eebfe86a56d633b9864e389b45dcb260,
0xa2f1ccba9395d7fcb155bba8bc92db9bafaeade7,
0xec8e57756626fdc07c63ad2eafbd28d08e7b0ca5,
0xd164b088bd9108b60d0ca3751da4bceb207b0782,
0x6231b6d0d5e77fe001c2a460bd9584fee60d409b,
0x1cba23d343a983e9b5cfd19496b9a9701ada385f,
0xa82f360a8d3455c5c41366975bde739c37bfeb8a,
0x9fcd2deaff372a39cc679d5c5e4de7bafb0b1339,
0x005f5cee7a43331d5a3d3eec71305925a62f34b6,
0x0e0da70933f4c7849fc0d203f5d1d43b9ae4532d,
0xd131637d5275fd1a68a3200f4ad25c71a2a9522e,
0xbc07118b9ac290e4622f5e77a0853539789effbe,
0x47e7aa56d6bdf3f36be34619660de61275420af8,
0xacd87e28b0c9d1254e868b81cba4cc20d9a32225,
0xadf80daec7ba8dcf15392f1ac611fff65d94f880,
0x5524c55fb03cf21f549444ccbecb664d0acad706,
0x40b803a9abce16f50f36a77ba41180eb90023925,
0xfe24cdd8648121a43a7c86d289be4dd2951ed49f,
0x17802f43a0137c506ba92291391a8a8f207f487d,
0x253488078a4edf4d6f42f113d1e62836a942cf1a,
0x86af3e9626fce1957c82e88cbf04ddf3a2ed7915,
0xb136707642a4ea12fb4bae820f03d2562ebff487,
0xdbe9b615a3ae8709af8b93336ce9b477e4ac0940,
0xf14c14075d6c4ed84b86798af0956deef67365b5,
0xca544e5c4687d109611d0f8f928b53a25af72448,
0xaeeb8ff27288bdabc0fa5ebb731b6f409507516c,
0xcbb9d3703e651b0d496cdefb8b92c25aeb2171f7,
0x6d87578288b6cb5549d5076a207456a1f6a63dc0,
0xb2c6f0dfbb716ac562e2d85d6cb2f8d5ee87603e,
0xaccc230e8a6e5be9160b8cdf2864dd2a001c28b6,
0x2b3455ec7fedf16e646268bf88846bd7a2319bb2,
0x4613f3bca5c44ea06337a9e439fbc6d42e501d0a,
0xd343b217de44030afaa275f54d31a9317c7f441e,
0x84ef4b2357079cd7a7c69fd7a37cd0609a679106,
0xda2fef9e4a3230988ff17df2165440f37e8b1708,
0xf4c64518ea10f995918a454158c6b61407ea345c,
0x7602b46df5390e432ef1c307d4f2c9ff6d65cc97,
0xbb9bc244d798123fde783fcc1c72d3bb8c189413,
0x807640a13483f8ac783c557fcdf27be11ea4ac7a
At the beginning of block 1920000, all ether throughout all accounts in L
will be transferred to a contract deployed at 0xbf4ed7b27f1d666546e30d74d50d173d20bca754
. The contract was created from the following Solidity code (compiler version v0.3.5-2016-07-01-48238c9
):
// Deployed on mainnet at 0xbf4ed7b27f1d666546e30d74d50d173d20bca754 contract DAO { function balanceOf(address addr) returns (uint); function transferFrom(address from, address to, uint balance) returns (bool); uint public totalSupply; } contract WithdrawDAO { DAO constant public mainDAO = DAO(0xbb9bc244d798123fde783fcc1c72d3bb8c189413); address public trustee = 0xda4a4626d3e16e094de3225a751aab7128e96526; function withdraw(){ uint balance = mainDAO.balanceOf(msg.sender); if (!mainDAO.transferFrom(msg.sender, this, balance) || !msg.sender.send(balance)) throw; } function trusteeWithdraw() { trustee.send((this.balance + mainDAO.balanceOf(this)) - mainDAO.totalSupply()); } }
This contract is deployed on Mainnet in block 1883496 in transaction hash 0xfeae1ff3cf9b6927d607744e3883ea105fb16042d4639857d9cfce3eba644286
. The deployment code of the contract is:
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
This deployment results in the runtime bytecode:
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
Blocks with block numbers in the range [1_920_000, 1_920_009] MUST have 0x64616f2d686172642d666f726b
(hex encoded ASCII string dao-hard-fork
) in the extraData
field of the block.
References
- https://blog.slock.it/hard-fork-specification-24b889e70703
- https://blog.ethereum.org/2016/07/15/to-fork-or-not-to-fork/
Copyright
Copyright and related rights waived via CC0.
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