'use strict';

const errors = require('internal/errors');
const {
  Sign: _Sign,
  Verify: _Verify
} = process.binding('crypto');
const {
  RSA_PSS_SALTLEN_AUTO,
  RSA_PKCS1_PADDING
} = process.binding('constants').crypto;
const {
  getDefaultEncoding,
  toBuf
} = require('internal/crypto/util');
const { Writable } = require('stream');
const { inherits } = require('util');

function Sign(algorithm, options) {
  if (!(this instanceof Sign))
    return new Sign(algorithm, options);
  this._handle = new _Sign();
  this._handle.init(algorithm);

  Writable.call(this, options);
}

inherits(Sign, Writable);

Sign.prototype._write = function _write(chunk, encoding, callback) {
  this._handle.update(chunk, encoding);
  callback();
};

Sign.prototype.update = function update(data, encoding) {
  encoding = encoding || getDefaultEncoding();
  this._handle.update(data, encoding);
  return this;
};

Sign.prototype.sign = function sign(options, encoding) {
  if (!options)
    throw new errors.Error('ERR_CRYPTO_SIGN_KEY_REQUIRED');

  var key = options.key || options;
  var passphrase = options.passphrase || null;

  // Options specific to RSA
  var rsaPadding = RSA_PKCS1_PADDING;
  if (options.hasOwnProperty('padding')) {
    if (options.padding === options.padding >> 0) {
      rsaPadding = options.padding;
    } else {
      throw new errors.TypeError('ERR_INVALID_OPT_VALUE',
                                 'padding',
                                 options.padding);
    }
  }

  var pssSaltLength = RSA_PSS_SALTLEN_AUTO;
  if (options.hasOwnProperty('saltLength')) {
    if (options.saltLength === options.saltLength >> 0) {
      pssSaltLength = options.saltLength;
    } else {
      throw new errors.TypeError('ERR_INVALID_OPT_VALUE',
                                 'saltLength',
                                 options.saltLength);
    }
  }

  var ret = this._handle.sign(toBuf(key), passphrase, rsaPadding,
                              pssSaltLength);

  encoding = encoding || getDefaultEncoding();
  if (encoding && encoding !== 'buffer')
    ret = ret.toString(encoding);

  return ret;
};


function Verify(algorithm, options) {
  if (!(this instanceof Verify))
    return new Verify(algorithm, options);

  this._handle = new _Verify();
  this._handle.init(algorithm);

  Writable.call(this, options);
}

inherits(Verify, Writable);

Verify.prototype._write = Sign.prototype._write;
Verify.prototype.update = Sign.prototype.update;

Verify.prototype.verify = function verify(options, signature, sigEncoding) {
  var key = options.key || options;
  sigEncoding = sigEncoding || getDefaultEncoding();

  // Options specific to RSA
  var rsaPadding = RSA_PKCS1_PADDING;
  if (options.hasOwnProperty('padding')) {
    if (options.padding === options.padding >> 0) {
      rsaPadding = options.padding;
    } else {
      throw new errors.TypeError('ERR_INVALID_OPT_VALUE',
                                 'padding',
                                 options.padding);
    }
  }

  var pssSaltLength = RSA_PSS_SALTLEN_AUTO;
  if (options.hasOwnProperty('saltLength')) {
    if (options.saltLength === options.saltLength >> 0) {
      pssSaltLength = options.saltLength;
    } else {
      throw new errors.TypeError('ERR_INVALID_OPT_VALUE',
                                 'saltLength',
                                 options.saltLength);
    }
  }

  return this._handle.verify(toBuf(key), toBuf(signature, sigEncoding),
                             rsaPadding, pssSaltLength);
};

module.exports = {
  Sign,
  Verify
};