Nano-Ethereum-Signer

If your application needs to sign and verify messages from Ethereum accounts, you need to include a library such as web3, ethereumjs or ethers.js, which increase the size of your builds by 300kb to 1mb+, which is wasteful if you just want signing functionality. As such, I made this library by aggressively, manually pruning dead code and branches. The result is a 52K file with Ethereum signing and verification functionality, which is the smallest I could get so far. Further optimizations may include replacing BN by native BitInt and more prunings.

Installing

npm i nano-ethereum-signer

Functions

// Gets an Ethereum address from a Private Key
ethsig.addressFromKey(private_key : Hex) : Hex

// Signs the hash of a message
ethsig.signMessage(message : Hex, private_key : Hex) : Hex

// Given the hash of a message and signature,
// returns the signer address
ethsig.signerAddress(message : Hex, signature : Hex) : Hex

// Converts an address to the checksum format
ethsig.addressChecksum(address : Hex)

// Keccak256 of a string or array of bytes. If the string
// starts with `0x`, it is interpreted as data. Otherwise,
// it is interpreted as UTF-8. If you want to always use
// UTF-8, pass an extra `true` argument. 
ethsig.keccak(message : String | Array<Uint8>) : Hex

Here, Hex is a string on the format "0x1234abcd...". Private keys and hashes have 256 bits (64 hex digits). Addresses have 160 bits (40 hex digits). Signatures have 520 bits (130 hex digits).