var createHash = require('create-hash') var stream = require('stream') var inherits = require('inherits') var sign = require('./sign') var verify = require('./verify') var algorithms = require('./algorithms.json') Object.keys(algorithms).forEach(function (key) { algorithms[key].id = new Buffer(algorithms[key].id, 'hex') algorithms[key.toLowerCase()] = algorithms[key] }) function Sign (algorithm) { stream.Writable.call(this) var data = algorithms[algorithm] if (!data) throw new Error('Unknown message digest') this._hashType = data.hash this._hash = createHash(data.hash) this._tag = data.id this._signType = data.sign } inherits(Sign, stream.Writable) Sign.prototype._write = function _write (data, _, done) { this._hash.update(data) done() } Sign.prototype.update = function update (data, enc) { if (typeof data === 'string') data = new Buffer(data, enc) this._hash.update(data) return this } Sign.prototype.sign = function signMethod (key, enc) { this.end() var hash = this._hash.digest() var sig = sign(hash, key, this._hashType, this._signType, this._tag) return enc ? sig.toString(enc) : sig } function Verify (algorithm) { stream.Writable.call(this) var data = algorithms[algorithm] if (!data) throw new Error('Unknown message digest') this._hash = createHash(data.hash) this._tag = data.id this._signType = data.sign } inherits(Verify, stream.Writable) Verify.prototype._write = function _write (data, _, done) { this._hash.update(data) done() } Verify.prototype.update = function update (data, enc) { if (typeof data === 'string') data = new Buffer(data, enc) this._hash.update(data) return this } Verify.prototype.verify = function verifyMethod (key, sig, enc) { if (typeof sig === 'string') sig = new Buffer(sig, enc) this.end() var hash = this._hash.digest() return verify(sig, hash, key, this._signType, this._tag) } function createSign (algorithm) { return new Sign(algorithm) } function createVerify (algorithm) { return new Verify(algorithm) } module.exports = { Sign: createSign, Verify: createVerify, createSign: createSign, createVerify: createVerify }