A learning record of contract and etherjs interaction.

It's my pleasure if this repo can help anyone who is planning to step into ethereum dApp development.

contract sign messageHash generation and signature verify

the keys you need to notify when you generate a offchain signature:

1. check signing message and hashed message

• use ethers.utils._TypedDataEncoder to encode signing typed message(equal to abi.encodePacked()).
• use ethers.utils.keccak256() to hash encoded message.(equal to keccak256(abi.encodePacked())).
• use ethers.utils.AbiCoder to encode simple message(equal to abi.encode()).

2. sign typed data directly

• utilize the signer._signTypedData() to sign typedData directly.
• utilize the signer.signMessage() to sign simple message.

3. choose three type of signature(based on ECDSA.sol) to verify onchain

• type1: bytesLik signature
• type2: r, s, v signature => need to split the signature: ethers.utils.splitSignature(signature)
• type3: r, vs signature => need to split the signature: ethers.utils.splitSignature(signature), and then concat the v,s bytes.