ethereumjs-util
Version:
A collection of utility functions for Ethereum
163 lines • 6.87 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.hashPersonalMessage = exports.isValidSignature = exports.fromRpcSig = exports.toCompactSig = exports.toRpcSig = exports.ecrecover = exports.ecsign = void 0;
const secp256k1_1 = require("ethereum-cryptography/secp256k1");
const externals_1 = require("./externals");
const bytes_1 = require("./bytes");
const hash_1 = require("./hash");
const helpers_1 = require("./helpers");
const types_1 = require("./types");
function ecsign(msgHash, privateKey, chainId) {
const { signature, recid: recovery } = (0, secp256k1_1.ecdsaSign)(msgHash, privateKey);
const r = Buffer.from(signature.slice(0, 32));
const s = Buffer.from(signature.slice(32, 64));
if (!chainId || typeof chainId === 'number') {
// return legacy type ECDSASignature (deprecated in favor of ECDSASignatureBuffer to handle large chainIds)
if (chainId && !Number.isSafeInteger(chainId)) {
throw new Error('The provided number is greater than MAX_SAFE_INTEGER (please use an alternative input type)');
}
const v = chainId ? recovery + (chainId * 2 + 35) : recovery + 27;
return { r, s, v };
}
const chainIdBN = (0, types_1.toType)(chainId, types_1.TypeOutput.BN);
const v = chainIdBN.muln(2).addn(35).addn(recovery).toArrayLike(Buffer);
return { r, s, v };
}
exports.ecsign = ecsign;
function calculateSigRecovery(v, chainId) {
const vBN = (0, types_1.toType)(v, types_1.TypeOutput.BN);
if (vBN.eqn(0) || vBN.eqn(1))
return (0, types_1.toType)(v, types_1.TypeOutput.BN);
if (!chainId) {
return vBN.subn(27);
}
const chainIdBN = (0, types_1.toType)(chainId, types_1.TypeOutput.BN);
return vBN.sub(chainIdBN.muln(2).addn(35));
}
function isValidSigRecovery(recovery) {
const rec = new externals_1.BN(recovery);
return rec.eqn(0) || rec.eqn(1);
}
/**
* ECDSA public key recovery from signature.
* NOTE: Accepts `v == 0 | v == 1` for EIP1559 transactions
* @returns Recovered public key
*/
const ecrecover = function (msgHash, v, r, s, chainId) {
const signature = Buffer.concat([(0, bytes_1.setLengthLeft)(r, 32), (0, bytes_1.setLengthLeft)(s, 32)], 64);
const recovery = calculateSigRecovery(v, chainId);
if (!isValidSigRecovery(recovery)) {
throw new Error('Invalid signature v value');
}
const senderPubKey = (0, secp256k1_1.ecdsaRecover)(signature, recovery.toNumber(), msgHash);
return Buffer.from((0, secp256k1_1.publicKeyConvert)(senderPubKey, false).slice(1));
};
exports.ecrecover = ecrecover;
/**
* Convert signature parameters into the format of `eth_sign` RPC method.
* NOTE: Accepts `v == 0 | v == 1` for EIP1559 transactions
* @returns Signature
*/
const toRpcSig = function (v, r, s, chainId) {
const recovery = calculateSigRecovery(v, chainId);
if (!isValidSigRecovery(recovery)) {
throw new Error('Invalid signature v value');
}
// geth (and the RPC eth_sign method) uses the 65 byte format used by Bitcoin
return (0, bytes_1.bufferToHex)(Buffer.concat([(0, bytes_1.setLengthLeft)(r, 32), (0, bytes_1.setLengthLeft)(s, 32), (0, bytes_1.toBuffer)(v)]));
};
exports.toRpcSig = toRpcSig;
/**
* Convert signature parameters into the format of Compact Signature Representation (EIP-2098).
* NOTE: Accepts `v == 0 | v == 1` for EIP1559 transactions
* @returns Signature
*/
const toCompactSig = function (v, r, s, chainId) {
const recovery = calculateSigRecovery(v, chainId);
if (!isValidSigRecovery(recovery)) {
throw new Error('Invalid signature v value');
}
const vn = (0, types_1.toType)(v, types_1.TypeOutput.Number);
let ss = s;
if ((vn > 28 && vn % 2 === 1) || vn === 1 || vn === 28) {
ss = Buffer.from(s);
ss[0] |= 0x80;
}
return (0, bytes_1.bufferToHex)(Buffer.concat([(0, bytes_1.setLengthLeft)(r, 32), (0, bytes_1.setLengthLeft)(ss, 32)]));
};
exports.toCompactSig = toCompactSig;
/**
* Convert signature format of the `eth_sign` RPC method to signature parameters
* NOTE: all because of a bug in geth: https://github.com/ethereum/go-ethereum/issues/2053
* NOTE: After EIP1559, `v` could be `0` or `1` but this function assumes
* it's a signed message (EIP-191 or EIP-712) adding `27` at the end. Remove if needed.
*/
const fromRpcSig = function (sig) {
const buf = (0, bytes_1.toBuffer)(sig);
let r;
let s;
let v;
if (buf.length >= 65) {
r = buf.slice(0, 32);
s = buf.slice(32, 64);
v = (0, bytes_1.bufferToInt)(buf.slice(64));
}
else if (buf.length === 64) {
// Compact Signature Representation (https://eips.ethereum.org/EIPS/eip-2098)
r = buf.slice(0, 32);
s = buf.slice(32, 64);
v = (0, bytes_1.bufferToInt)(buf.slice(32, 33)) >> 7;
s[0] &= 0x7f;
}
else {
throw new Error('Invalid signature length');
}
// support both versions of `eth_sign` responses
if (v < 27) {
v += 27;
}
return {
v,
r,
s,
};
};
exports.fromRpcSig = fromRpcSig;
/**
* Validate a ECDSA signature.
* NOTE: Accepts `v == 0 | v == 1` for EIP1559 transactions
* @param homesteadOrLater Indicates whether this is being used on either the homestead hardfork or a later one
*/
const isValidSignature = function (v, r, s, homesteadOrLater = true, chainId) {
const SECP256K1_N_DIV_2 = new externals_1.BN('7fffffffffffffffffffffffffffffff5d576e7357a4501ddfe92f46681b20a0', 16);
const SECP256K1_N = new externals_1.BN('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141', 16);
if (r.length !== 32 || s.length !== 32) {
return false;
}
if (!isValidSigRecovery(calculateSigRecovery(v, chainId))) {
return false;
}
const rBN = new externals_1.BN(r);
const sBN = new externals_1.BN(s);
if (rBN.isZero() || rBN.gt(SECP256K1_N) || sBN.isZero() || sBN.gt(SECP256K1_N)) {
return false;
}
if (homesteadOrLater && sBN.cmp(SECP256K1_N_DIV_2) === 1) {
return false;
}
return true;
};
exports.isValidSignature = isValidSignature;
/**
* Returns the keccak-256 hash of `message`, prefixed with the header used by the `eth_sign` RPC call.
* The output of this function can be fed into `ecsign` to produce the same signature as the `eth_sign`
* call for a given `message`, or fed to `ecrecover` along with a signature to recover the public key
* used to produce the signature.
*/
const hashPersonalMessage = function (message) {
(0, helpers_1.assertIsBuffer)(message);
const prefix = Buffer.from(`\u0019Ethereum Signed Message:\n${message.length}`, 'utf-8');
return (0, hash_1.keccak)(Buffer.concat([prefix, message]));
};
exports.hashPersonalMessage = hashPersonalMessage;
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