| ======= contracts/Migrations.sol:Migrations ======= | |
| EVM assembly: | |
| /* "contracts/Migrations.sol":26:514 contract Migrations {... */ | |
| mstore(0x40, 0x60) | |
| /* "contracts/Migrations.sol":178:236 function Migrations() public {... */ | |
| jumpi(tag_1, iszero(callvalue)) | |
| 0x0 | |
| dup1 | |
| revert |
| pragma solidity ^0.4.10; | |
| contract A { | |
| address alice = 0x14723a09acff6d2a60dcdf7aa4aff308fddc160c; | |
| address bob = 0x4b0897b0513fdc7c541b6d9d7e929c4e5364d2db; | |
| function foo() public { | |
| selfdestruct(alice); // alice gets the ETH. | |
| selfdestruct(bob); | |
| } |
| <html> | |
| <head> | |
| <style type="text/css"> | |
| #mynetwork { | |
| background-color: #ffffff; | |
| } | |
| body { |
| { | |
| "extends": "default", | |
| "rules": { | |
| "reentrancy": false, | |
| "avoid-sha3": false, | |
| "avoid-suicide": false, | |
| "avoid-throw": false, | |
| "func-visibility": false, | |
| "state-visibility": false, | |
| "check-send-result": false, |
| layout | post |
|---|---|
| title | easily read private variables |
| date | 2018-03-29 09:30 |
I put this together to demonstrate that complete lack of "privacy" provided by labelling a variable private in solidity.
If you want to read a private variable in a solidity contract, and you have the source code, you can do it easily. Here's how:
| pragma solidity ^0.4.10; | |
| contract A { | |
| event LogGas(uint); | |
| function foo() { | |
| uint beforeGas = msg.gas; | |
| // emit LogGas(beforeGas); | |
| assembly { |
| 0x5c79d3d994b54f98cedb0c5d9be4842f26e2fe10 |
| Yup: event({_yup: bool}) | |
| max_uint_256: public(uint256) | |
| @public | |
| def __init__(): | |
| self.max_uint_256 = 2*(2**255-1)+1 | |
| @public | |
| def lessThanMaxUint(a: uint256) -> (bool): |
| # Attempt 1 | |
| other_contract: address | |
| @public | |
| def __init__(): | |
| self.other_contract = 0x1111111000000000000000000000000000000000 | |
| @public | |
| def foo(): |
| pragma experimental SMTChecker; | |
| // pragma solidity ^0.4.20; | |
| contract Primes { | |
| function prime(uint a, uint b) public pure { | |
| require(1 < a && a < 500); | |
| require(1 < b && b < 25000); | |
| assert(a * b != 23447); | |
| } |
