RSA signature verification in Ethereum
Please first read this blog post explaining the landscape.
Good, so you are interested how this is done in practice. The high level description is explained in this EIP proposal.
You'll need the following pieces to try this out:
browser-solidity with rsaverify support
the attached rsaverify.sol for the wrapper in Solidity
and a piece of Solidity code using it
Example code
import "https://github.com/axic/ethereum-rsa/rsaverify.sol";
contract Test {
function test(bytes msg, bytes N, uint e, bytes S) returns (bool) {
return RSAVerify.rsaverify(msg, N, e, S, 1);
}
}
NOTE: as much as I like using libraries, the wrapper code breaks with delegatecall. For now you must resort to using rsaverify as an inherited contracted. Or just copy the code from rsaverify.sol into your project.
And then pass one of the following sample inputs:
512 bit key
msg: 0xcd8d103034f3796038d906de40faf3c3ba118a6b
N: 0x00890e68c2485f2c725116f259a7ac871e1de3618dfc41e1df8eacc0131b2d433de6ed6d1f36bbf5a401d5afa32eeb2d444cf02a920c81f8088ba0b99d47a0bfdf
e: 65537
S: 0x77c6b0c53800d37b6b946df6d91a693c25b1ba97cac16879a10b3231a5cea0932a0bc16443b2e82b33ec155a61b29572a5faaf574152bd509a248fdb8ed9d7af
paddingScheme: 1
2048 bit key
msg: 0x70dd0c1b74d12222bc1e5257bd8c2d45b816202c
N: 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
e: 65537
S: 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
paddingScheme: 1
Building ethereumjs-vm
Clone https://github.com/ethereumjs/browser-builds and change the ethereumjs-vm version in package.json to:
git+https://github.com/axic/ethereumjs-vm#feature/rsaverify
Run ./build.sh
Take dist/ethereumjs-vm.js
Building browser-solidity
Follow the instructions in https://github.com/chriseth/browser-solidity about running it locally.
Replace assets/js/ethereumjs-vm.js with the one created in the previous process.
Congratulations, you now have a working environment.
The changed sources
License
MIT License
Copyright (C) 2016 Alex Beregszaszi