EIP-191 と EIP-712 の比較｜personal_sign か型付きデータ署名か

import { secp256k1 } from "@noble/curves/secp256k1.js";
import { keccak_256 } from "@noble/hashes/sha3.js";
import { bytesToHex, concatBytes, hexToBytes, utf8ToBytes } from "@noble/hashes/utils.js";

const hex = (b) => "0x" + bytesToHex(b);
// Test key published in the EIP-712 reference example (assets/eip-712/Example.js): keccak256("cow").
// It is public, so never send funds to its address.
const secretKey = keccak_256(utf8ToBytes("cow"));
const signer = hex(keccak_256(secp256k1.getPublicKey(secretKey, false).subarray(1)).subarray(12));
const sign = (digest) => {
  const sig = secp256k1.sign(digest, secretKey, { prehash: false, format: "recovered" });
  return { v: sig[0] + 27, r: hex(sig.subarray(1, 33)), s: hex(sig.subarray(33)) };
};

// EIP-191 version 0x45: personal_sign
const text = utf8ToBytes("hello");
const personalDigest = keccak_256(concatBytes(utf8ToBytes(`\x19Ethereum Signed Message:\n${text.length}`), text));
console.log("EIP-191 personal_sign digest:", hex(personalDigest));

// EIP-712: typed structured data (the "Ether Mail" example from the EIP)
const types = {
  EIP712Domain: [["name", "string"], ["version", "string"], ["chainId", "uint256"], ["verifyingContract", "address"]],
  Person: [["name", "string"], ["wallet", "address"]],
  Mail: [["from", "Person"], ["to", "Person"], ["contents", "string"]],
};
const encodeType = (primary) => {
  const deps = new Set();
  const walk = (t) => types[t].forEach(([, ft]) => { if (types[ft] && !deps.has(ft)) { deps.add(ft); walk(ft); } });
  walk(primary);
  return [primary, ...[...deps].sort()].map((t) => `${t}(${types[t].map(([n, ft]) => `${ft} ${n}`).join(",")})`).join("");
};
const encodeValue = (ft, v) =>
  types[ft] ? hashStruct(ft, v)
  : ft === "string" ? keccak_256(utf8ToBytes(v))
  : ft === "address" ? concatBytes(new Uint8Array(12), hexToBytes(v.slice(2)))
  : hexToBytes(BigInt(v).toString(16).padStart(64, "0")); // uint256
const hashStruct = (t, v) =>
  keccak_256(concatBytes(keccak_256(utf8ToBytes(encodeType(t))), ...types[t].map(([n, ft]) => encodeValue(ft, v[n]))));

const domain = { name: "Ether Mail", version: "1", chainId: 1, verifyingContract: "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC" };
const mail = {
  from: { name: "Cow", wallet: "0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826" },
  to: { name: "Bob", wallet: "0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB" },
  contents: "Hello, Bob!",
};
const typedDigest = (d) => keccak_256(concatBytes(new Uint8Array([0x19, 0x01]), hashStruct("EIP712Domain", d), hashStruct("Mail", mail)));

console.log("encodeType(Mail):", encodeType("Mail"));
console.log("domainSeparator:", hex(hashStruct("EIP712Domain", domain)));
console.log("hashStruct(Mail):", hex(hashStruct("Mail", mail)));
console.log("EIP-712 digest:", hex(typedDigest(domain)));
console.log("signer:", signer, sign(typedDigest(domain)));
console.log("same mail, chainId 10:", hex(typedDigest({ ...domain, chainId: 10 })));

EIP-191 personal_sign digest: 0x50b2c43fd39106bafbba0da34fc430e1f91e3c96ea2acee2bc34119f92b37750
encodeType(Mail): Mail(Person from,Person to,string contents)Person(string name,address wallet)
domainSeparator: 0xf2cee375fa42b42143804025fc449deafd50cc031ca257e0b194a650a912090f
hashStruct(Mail): 0xc52c0ee5d84264471806290a3f2c4cecfc5490626bf912d01f240d7a274b371e
EIP-712 digest: 0xbe609aee343fb3c4b28e1df9e632fca64fcfaede20f02e86244efddf30957bd2
signer: 0xcd2a3d9f938e13cd947ec05abc7fe734df8dd826 {
  v: 28,
  r: '0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d',
  s: '0x07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b91562'
}
same mail, chainId 10: 0x2752db86097e9749484b4645855d9ff3d1b6109c89ed55a9d7f9021dbc77bcf9