151 lines
5.7 KiB
JavaScript
151 lines
5.7 KiB
JavaScript
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import { keccak256 } from 'ethereum-cryptography/keccak.js';
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import { secp256k1 } from 'ethereum-cryptography/secp256k1.js';
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import { bytesToBigInt, bytesToHex, bytesToInt, concatBytes, setLengthLeft, toBytes, utf8ToBytes, } from './bytes.js';
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import { BIGINT_0, BIGINT_1, BIGINT_2, BIGINT_27, SECP256K1_ORDER, SECP256K1_ORDER_DIV_2, } from './constants.js';
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import { assertIsBytes } from './helpers.js';
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/**
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* Returns the ECDSA signature of a message hash.
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*
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* If `chainId` is provided assume an EIP-155-style signature and calculate the `v` value
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* accordingly, otherwise return a "static" `v` just derived from the `recovery` bit
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*/
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export function ecsign(msgHash, privateKey, chainId) {
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const sig = secp256k1.sign(msgHash, privateKey);
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const buf = sig.toCompactRawBytes();
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const r = buf.slice(0, 32);
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const s = buf.slice(32, 64);
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const v = chainId === undefined
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? BigInt(sig.recovery + 27)
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: BigInt(sig.recovery + 35) + BigInt(chainId) * BIGINT_2;
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return { r, s, v };
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}
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export function calculateSigRecovery(v, chainId) {
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if (v === BIGINT_0 || v === BIGINT_1)
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return v;
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if (chainId === undefined) {
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return v - BIGINT_27;
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}
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return v - (chainId * BIGINT_2 + BigInt(35));
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}
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function isValidSigRecovery(recovery) {
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return recovery === BIGINT_0 || recovery === BIGINT_1;
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}
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/**
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* ECDSA public key recovery from signature.
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* NOTE: Accepts `v === 0 | v === 1` for EIP1559 transactions
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* @returns Recovered public key
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*/
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export const ecrecover = function (msgHash, v, r, s, chainId) {
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const signature = concatBytes(setLengthLeft(r, 32), setLengthLeft(s, 32));
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const recovery = calculateSigRecovery(v, chainId);
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if (!isValidSigRecovery(recovery)) {
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throw new Error('Invalid signature v value');
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}
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const sig = secp256k1.Signature.fromCompact(signature).addRecoveryBit(Number(recovery));
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const senderPubKey = sig.recoverPublicKey(msgHash);
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return senderPubKey.toRawBytes(false).slice(1);
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};
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/**
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* Convert signature parameters into the format of `eth_sign` RPC method.
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* NOTE: Accepts `v === 0 | v === 1` for EIP1559 transactions
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* @returns Signature
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*/
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export const toRpcSig = function (v, r, s, chainId) {
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const recovery = calculateSigRecovery(v, chainId);
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if (!isValidSigRecovery(recovery)) {
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throw new Error('Invalid signature v value');
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}
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// geth (and the RPC eth_sign method) uses the 65 byte format used by Bitcoin
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return bytesToHex(concatBytes(setLengthLeft(r, 32), setLengthLeft(s, 32), toBytes(v)));
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};
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/**
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* Convert signature parameters into the format of Compact Signature Representation (EIP-2098).
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* NOTE: Accepts `v === 0 | v === 1` for EIP1559 transactions
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* @returns Signature
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*/
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export const toCompactSig = function (v, r, s, chainId) {
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const recovery = calculateSigRecovery(v, chainId);
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if (!isValidSigRecovery(recovery)) {
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throw new Error('Invalid signature v value');
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}
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const ss = Uint8Array.from([...s]);
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if ((v > BigInt(28) && v % BIGINT_2 === BIGINT_1) || v === BIGINT_1 || v === BigInt(28)) {
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ss[0] |= 0x80;
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}
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return bytesToHex(concatBytes(setLengthLeft(r, 32), setLengthLeft(ss, 32)));
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};
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/**
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* Convert signature format of the `eth_sign` RPC method to signature parameters
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*
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* NOTE: For an extracted `v` value < 27 (see Geth bug https://github.com/ethereum/go-ethereum/issues/2053)
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* `v + 27` is returned for the `v` value
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* NOTE: After EIP1559, `v` could be `0` or `1` but this function assumes
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* it's a signed message (EIP-191 or EIP-712) adding `27` at the end. Remove if needed.
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*/
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export const fromRpcSig = function (sig) {
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const bytes = toBytes(sig);
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let r;
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let s;
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let v;
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if (bytes.length >= 65) {
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r = bytes.subarray(0, 32);
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s = bytes.subarray(32, 64);
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v = bytesToBigInt(bytes.subarray(64));
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}
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else if (bytes.length === 64) {
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// Compact Signature Representation (https://eips.ethereum.org/EIPS/eip-2098)
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r = bytes.subarray(0, 32);
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s = bytes.subarray(32, 64);
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v = BigInt(bytesToInt(bytes.subarray(32, 33)) >> 7);
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s[0] &= 0x7f;
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}
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else {
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throw new Error('Invalid signature length');
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}
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// support both versions of `eth_sign` responses
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if (v < 27) {
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v = v + BIGINT_27;
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}
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return {
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v,
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r,
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s,
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};
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};
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/**
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* Validate a ECDSA signature.
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* NOTE: Accepts `v === 0 | v === 1` for EIP1559 transactions
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* @param homesteadOrLater Indicates whether this is being used on either the homestead hardfork or a later one
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*/
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export const isValidSignature = function (v, r, s, homesteadOrLater = true, chainId) {
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if (r.length !== 32 || s.length !== 32) {
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return false;
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}
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if (!isValidSigRecovery(calculateSigRecovery(v, chainId))) {
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return false;
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}
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const rBigInt = bytesToBigInt(r);
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const sBigInt = bytesToBigInt(s);
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if (rBigInt === BIGINT_0 ||
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rBigInt >= SECP256K1_ORDER ||
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sBigInt === BIGINT_0 ||
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sBigInt >= SECP256K1_ORDER) {
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return false;
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}
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if (homesteadOrLater && sBigInt >= SECP256K1_ORDER_DIV_2) {
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return false;
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}
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return true;
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};
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/**
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* Returns the keccak-256 hash of `message`, prefixed with the header used by the `eth_sign` RPC call.
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* The output of this function can be fed into `ecsign` to produce the same signature as the `eth_sign`
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* call for a given `message`, or fed to `ecrecover` along with a signature to recover the public key
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* used to produce the signature.
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*/
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export const hashPersonalMessage = function (message) {
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assertIsBytes(message);
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const prefix = utf8ToBytes(`\u0019Ethereum Signed Message:\n${message.length}`);
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return keccak256(concatBytes(prefix, message));
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};
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//# sourceMappingURL=signature.js.map
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