ethers.js/src.ts/utils/secp256k1.ts
2018-06-17 16:47:28 -04:00

128 lines
3.8 KiB
TypeScript

'use strict';
import { getAddress } from './address';
import { arrayify, Arrayish, hexlify } from './bytes';
import { keccak256 } from './keccak256';
import { defineReadOnly } from './properties';
import * as errors from './errors';
interface _BN {
toString(radix: number): string;
encode(encoding: string, compact: boolean): Uint8Array;
toArray(endian: string, width: number): Uint8Array;
}
interface _Signature {
r: _BN,
s: _BN,
recoveryParam: number
}
interface _KeyPair {
sign(message: Uint8Array, options: { canonical?: boolean }): _Signature;
getPublic(compressed: boolean, encoding?: string): string;
getPublic(): _BN;
getPrivate(encoding?: string): string;
encode(encoding: string, compressed: boolean): string;
priv: _BN;
}
interface _EC {
constructor(curve: string);
n: _BN;
keyFromPublic(publicKey: string | Uint8Array): _KeyPair;
keyFromPrivate(privateKey: string | Uint8Array): _KeyPair;
recoverPubKey(data: Uint8Array, signature: { r: Uint8Array, s: Uint8Array }, recoveryParam: number): _KeyPair;
}
import * as elliptic from 'elliptic';
const curve:_EC = new elliptic.ec('secp256k1');
export const N = '0x' + curve.n.toString(16);
export interface Signature {
r: string;
s: string;
recoveryParam: number;
v?: number;
}
export class KeyPair {
readonly privateKey: string;
readonly publicKey: string;
readonly compressedPublicKey: string;
readonly publicKeyBytes: Uint8Array;
constructor(privateKey: Arrayish) {
let keyPair: _KeyPair = curve.keyFromPrivate(arrayify(privateKey));
defineReadOnly(this, 'privateKey', hexlify(keyPair.priv.toArray('be', 32)));
defineReadOnly(this, 'publicKey', '0x' + keyPair.getPublic(false, 'hex'));
defineReadOnly(this, 'compressedPublicKey', '0x' + keyPair.getPublic(true, 'hex'));
defineReadOnly(this, 'publicKeyBytes', keyPair.getPublic().encode(null, true));
}
sign(digest: Arrayish): Signature {
let keyPair: _KeyPair = curve.keyFromPrivate(arrayify(this.privateKey));
let signature = keyPair.sign(arrayify(digest), {canonical: true});
return {
recoveryParam: signature.recoveryParam,
r: '0x' + signature.r.toString(16),
s: '0x' + signature.s.toString(16),
v: 27 + signature.recoveryParam
}
}
}
export function recoverPublicKey(digest: Arrayish, signature: Signature): string {
let sig = {
r: arrayify(signature.r),
s: arrayify(signature.s)
};
return '0x' + curve.recoverPubKey(arrayify(digest), sig, signature.recoveryParam).encode('hex', false);
}
export function computePublicKey(key: Arrayish, compressed?: boolean): string {
let bytes = arrayify(key);
if (bytes.length === 32) {
let keyPair: KeyPair = new KeyPair(bytes);
if (compressed) {
return keyPair.compressedPublicKey;
}
return keyPair.publicKey;
} else if (bytes.length === 33) {
if (compressed) { return hexlify(bytes); }
return '0x' + curve.keyFromPublic(bytes).getPublic(false, 'hex');
} else if (bytes.length === 65) {
if (!compressed) { return hexlify(bytes); }
return '0x' + curve.keyFromPublic(bytes).getPublic(true, 'hex');
}
errors.throwError('invalid public or private key', errors.INVALID_ARGUMENT, { arg: 'key', value: '[REDACTED]' });
return null;
}
export function recoverAddress(digest: Arrayish, signature: Signature): string {
return computeAddress(recoverPublicKey(digest, signature));
}
export function computeAddress(key: string): string {
// Strip off the leading "0x04"
let publicKey = '0x' + computePublicKey(key).slice(4);
return getAddress('0x' + keccak256(publicKey).substring(26));
}