code:
/**
 * Socket implementation that uses flash SocketPool class as a backend.
 *
 * @author Dave Longley
 *
 * Copyright (c) 2010-2013 Digital Bazaar, Inc.
 */
var forge = require('./forge');
require('./util');

// define net namespace
var net = module.exports = forge.net = forge.net || {};

// map of flash ID to socket pool
net.socketPools = {};

/**
 * Creates a flash socket pool.
 *
 * @param options:
 *          flashId: the dom ID for the flash object element.
 *          policyPort: the default policy port for sockets, 0 to use the
 *            flash default.
 *          policyUrl: the default policy file URL for sockets (if provided
 *            used instead of a policy port).
 *          msie: true if the browser is msie, false if not.
 *
 * @return the created socket pool.
 */
net.createSocketPool = function(options) {
  // set default
  options.msie = options.msie || false;

  // initialize the flash interface
  var spId = options.flashId;
  var api = document.getElementById(spId);
  api.init({marshallExceptions: !options.msie});

  // create socket pool entry
  var sp = {
    // ID of the socket pool
    id: spId,
    // flash interface
    flashApi: api,
    // map of socket ID to sockets
    sockets: {},
    // default policy port
    policyPort: options.policyPort || 0,
    // default policy URL
    policyUrl: options.policyUrl || null
  };
  net.socketPools[spId] = sp;

  // create event handler, subscribe to flash events
  if(options.msie === true) {
    sp.handler = function(e) {
      if(e.id in sp.sockets) {
        // get handler function
        var f;
        switch(e.type) {
        case 'connect':
          f = 'connected';
          break;
        case 'close':
          f = 'closed';
          break;
        case 'socketData':
          f = 'data';
          break;
        default:
          f = 'error';
          break;
        }
        /* IE calls javascript on the thread of the external object
          that triggered the event (in this case flash) ... which will
          either run concurrently with other javascript or pre-empt any
          running javascript in the middle of its execution (BAD!) ...
          calling setTimeout() will schedule the javascript to run on
          the javascript thread and solve this EVIL problem. */
        setTimeout(function() {sp.sockets[e.id][f](e);}, 0);
      }
    };
  } else {
    sp.handler = function(e) {
      if(e.id in sp.sockets) {
        // get handler function
        var f;
        switch(e.type) {
        case 'connect':
          f = 'connected';
          break;
        case 'close':
          f = 'closed';
          break;
        case 'socketData':
          f = 'data';
          break;
        default:
          f = 'error';
          break;
        }
        sp.sockets[e.id][f](e);
      }
    };
  }
  var handler = 'forge.net.socketPools[\'' + spId + '\'].handler';
  api.subscribe('connect', handler);
  api.subscribe('close', handler);
  api.subscribe('socketData', handler);
  api.subscribe('ioError', handler);
  api.subscribe('securityError', handler);

  /**
   * Destroys a socket pool. The socket pool still needs to be cleaned
   * up via net.cleanup().
   */
  sp.destroy = function() {
    delete net.socketPools[options.flashId];
    for(var id in sp.sockets) {
      sp.sockets[id].destroy();
    }
    sp.sockets = {};
    api.cleanup();
  };

  /**
   * Creates a new socket.
   *
   * @param options:
   *          connected: function(event) called when the socket connects.
   *          closed: function(event) called when the socket closes.
   *          data: function(event) called when socket data has arrived,
   *            it can be read from the socket using receive().
   *          error: function(event) called when a socket error occurs.
   */
   sp.createSocket = function(options) {
     // default to empty options
     options = options || {};

     // create flash socket
     var id = api.create();

     // create javascript socket wrapper
     var socket = {
       id: id,
       // set handlers
       connected: options.connected || function(e) {},
       closed: options.closed || function(e) {},
       data: options.data || function(e) {},
       error: options.error || function(e) {}
     };

     /**
      * Destroys this socket.
      */
     socket.destroy = function() {
       api.destroy(id);
       delete sp.sockets[id];
     };

     /**
      * Connects this socket.
      *
      * @param options:
      *          host: the host to connect to.
      *          port: the port to connect to.
      *          policyPort: the policy port to use (if non-default), 0 to
      *            use the flash default.
      *          policyUrl: the policy file URL to use (instead of port).
      */
     socket.connect = function(options) {
       // give precedence to policy URL over policy port
       // if no policy URL and passed port isn't 0, use default port,
       // otherwise use 0 for the port
       var policyUrl = options.policyUrl || null;
       var policyPort = 0;
       if(policyUrl === null && options.policyPort !== 0) {
         policyPort = options.policyPort || sp.policyPort;
       }
       api.connect(id, options.host, options.port, policyPort, policyUrl);
     };

     /**
      * Closes this socket.
      */
     socket.close = function() {
       api.close(id);
       socket.closed({
         id: socket.id,
         type: 'close',
         bytesAvailable: 0
       });
     };

     /**
      * Determines if the socket is connected or not.
      *
      * @return true if connected, false if not.
      */
     socket.isConnected = function() {
       return api.isConnected(id);
     };

     /**
      * Writes bytes to this socket.
      *
      * @param bytes the bytes (as a string) to write.
      *
      * @return true on success, false on failure.
      */
     socket.send = function(bytes) {
       return api.send(id, forge.util.encode64(bytes));
     };

     /**
      * Reads bytes from this socket (non-blocking). Fewer than the number
      * of bytes requested may be read if enough bytes are not available.
      *
      * This method should be called from the data handler if there are
      * enough bytes available. To see how many bytes are available, check
      * the 'bytesAvailable' property on the event in the data handler or
      * call the bytesAvailable() function on the socket. If the browser is
      * msie, then the bytesAvailable() function should be used to avoid
      * race conditions. Otherwise, using the property on the data handler's
      * event may be quicker.
      *
      * @param count the maximum number of bytes to read.
      *
      * @return the bytes read (as a string) or null on error.
      */
     socket.receive = function(count) {
       var rval = api.receive(id, count).rval;
       return (rval === null) ? null : forge.util.decode64(rval);
     };

     /**
      * Gets the number of bytes available for receiving on the socket.
      *
      * @return the number of bytes available for receiving.
      */
     socket.bytesAvailable = function() {
       return api.getBytesAvailable(id);
     };

     // store and return socket
     sp.sockets[id] = socket;
     return socket;
  };

  return sp;
};

/**
 * Destroys a flash socket pool.
 *
 * @param options:
 *          flashId: the dom ID for the flash object element.
 */
net.destroySocketPool = function(options) {
  if(options.flashId in net.socketPools) {
    var sp = net.socketPools[options.flashId];
    sp.destroy();
  }
};

/**
 * Creates a new socket.
 *
 * @param options:
 *          flashId: the dom ID for the flash object element.
 *          connected: function(event) called when the socket connects.
 *          closed: function(event) called when the socket closes.
 *          data: function(event) called when socket data has arrived, it
 *            can be read from the socket using receive().
 *          error: function(event) called when a socket error occurs.
 *
 * @return the created socket.
 */
net.createSocket = function(options) {
  var socket = null;
  if(options.flashId in net.socketPools) {
    // get related socket pool
    var sp = net.socketPools[options.flashId];
    socket = sp.createSocket(options);
  }
  return socket;
};


code:
/**
 * Functions to output keys in SSH-friendly formats.
 *
 * This is part of the Forge project which may be used under the terms of
 * either the BSD License or the GNU General Public License (GPL) Version 2.
 *
 * See: https://github.com/digitalbazaar/forge/blob/cbebca3780658703d925b61b2caffb1d263a6c1d/LICENSE
 *
 * @author https://github.com/shellac
 */
var forge = require('./forge');
require('./aes');
require('./hmac');
require('./md5');
require('./sha1');
require('./util');

var ssh = module.exports = forge.ssh = forge.ssh || {};

/**
 * Encodes (and optionally encrypts) a private RSA key as a Putty PPK file.
 *
 * @param privateKey the key.
 * @param passphrase a passphrase to protect the key (falsy for no encryption).
 * @param comment a comment to include in the key file.
 *
 * @return the PPK file as a string.
 */
ssh.privateKeyToPutty = function(privateKey, passphrase, comment) {
  comment = comment || '';
  passphrase = passphrase || '';
  var algorithm = 'ssh-rsa';
  var encryptionAlgorithm = (passphrase === '') ? 'none' : 'aes256-cbc';

  var ppk = 'PuTTY-User-Key-File-2: ' + algorithm + '\r\n';
  ppk += 'Encryption: ' + encryptionAlgorithm + '\r\n';
  ppk += 'Comment: ' + comment + '\r\n';

  // public key into buffer for ppk
  var pubbuffer = forge.util.createBuffer();
  _addStringToBuffer(pubbuffer, algorithm);
  _addBigIntegerToBuffer(pubbuffer, privateKey.e);
  _addBigIntegerToBuffer(pubbuffer, privateKey.n);

  // write public key
  var pub = forge.util.encode64(pubbuffer.bytes(), 64);
  var length = Math.floor(pub.length / 66) + 1; // 66 = 64 + \r\n
  ppk += 'Public-Lines: ' + length + '\r\n';
  ppk += pub;

  // private key into a buffer
  var privbuffer = forge.util.createBuffer();
  _addBigIntegerToBuffer(privbuffer, privateKey.d);
  _addBigIntegerToBuffer(privbuffer, privateKey.p);
  _addBigIntegerToBuffer(privbuffer, privateKey.q);
  _addBigIntegerToBuffer(privbuffer, privateKey.qInv);

  // optionally encrypt the private key
  var priv;
  if(!passphrase) {
    // use the unencrypted buffer
    priv = forge.util.encode64(privbuffer.bytes(), 64);
  } else {
    // encrypt RSA key using passphrase
    var encLen = privbuffer.length() + 16 - 1;
    encLen -= encLen % 16;

    // pad private key with sha1-d data -- needs to be a multiple of 16
    var padding = _sha1(privbuffer.bytes());

    padding.truncate(padding.length() - encLen + privbuffer.length());
    privbuffer.putBuffer(padding);

    var aeskey = forge.util.createBuffer();
    aeskey.putBuffer(_sha1('\x00\x00\x00\x00', passphrase));
    aeskey.putBuffer(_sha1('\x00\x00\x00\x01', passphrase));

    // encrypt some bytes using CBC mode
    // key is 40 bytes, so truncate *by* 8 bytes
    var cipher = forge.aes.createEncryptionCipher(aeskey.truncate(8), 'CBC');
    cipher.start(forge.util.createBuffer().fillWithByte(0, 16));
    cipher.update(privbuffer.copy());
    cipher.finish();
    var encrypted = cipher.output;

    // Note: this appears to differ from Putty -- is forge wrong, or putty?
    // due to padding we finish as an exact multiple of 16
    encrypted.truncate(16); // all padding

    priv = forge.util.encode64(encrypted.bytes(), 64);
  }

  // output private key
  length = Math.floor(priv.length / 66) + 1; // 64 + \r\n
  ppk += '\r\nPrivate-Lines: ' + length + '\r\n';
  ppk += priv;

  // MAC
  var mackey = _sha1('putty-private-key-file-mac-key', passphrase);

  var macbuffer = forge.util.createBuffer();
  _addStringToBuffer(macbuffer, algorithm);
  _addStringToBuffer(macbuffer, encryptionAlgorithm);
  _addStringToBuffer(macbuffer, comment);
  macbuffer.putInt32(pubbuffer.length());
  macbuffer.putBuffer(pubbuffer);
  macbuffer.putInt32(privbuffer.length());
  macbuffer.putBuffer(privbuffer);

  var hmac = forge.hmac.create();
  hmac.start('sha1', mackey);
  hmac.update(macbuffer.bytes());

  ppk += '\r\nPrivate-MAC: ' + hmac.digest().toHex() + '\r\n';

  return ppk;
};

/**
 * Encodes a public RSA key as an OpenSSH file.
 *
 * @param key the key.
 * @param comment a comment.
 *
 * @return the public key in OpenSSH format.
 */
ssh.publicKeyToOpenSSH = function(key, comment) {
  var type = 'ssh-rsa';
  comment = comment || '';

  var buffer = forge.util.createBuffer();
  _addStringToBuffer(buffer, type);
  _addBigIntegerToBuffer(buffer, key.e);
  _addBigIntegerToBuffer(buffer, key.n);

  return type + ' ' + forge.util.encode64(buffer.bytes()) + ' ' + comment;
};

/**
 * Encodes a private RSA key as an OpenSSH file.
 *
 * @param key the key.
 * @param passphrase a passphrase to protect the key (falsy for no encryption).
 *
 * @return the public key in OpenSSH format.
 */
ssh.privateKeyToOpenSSH = function(privateKey, passphrase) {
  if(!passphrase) {
    return forge.pki.privateKeyToPem(privateKey);
  }
  // OpenSSH private key is just a legacy format, it seems
  return forge.pki.encryptRsaPrivateKey(privateKey, passphrase,
    {legacy: true, algorithm: 'aes128'});
};

/**
 * Gets the SSH fingerprint for the given public key.
 *
 * @param options the options to use.
 *          [md] the message digest object to use (defaults to forge.md.md5).
 *          [encoding] an alternative output encoding, such as 'hex'
 *            (defaults to none, outputs a byte buffer).
 *          [delimiter] the delimiter to use between bytes for 'hex' encoded
 *            output, eg: ':' (defaults to none).
 *
 * @return the fingerprint as a byte buffer or other encoding based on options.
 */
ssh.getPublicKeyFingerprint = function(key, options) {
  options = options || {};
  var md = options.md || forge.md.md5.create();

  var type = 'ssh-rsa';
  var buffer = forge.util.createBuffer();
  _addStringToBuffer(buffer, type);
  _addBigIntegerToBuffer(buffer, key.e);
  _addBigIntegerToBuffer(buffer, key.n);

  // hash public key bytes
  md.start();
  md.update(buffer.getBytes());
  var digest = md.digest();
  if(options.encoding === 'hex') {
    var hex = digest.toHex();
    if(options.delimiter) {
      return hex.match(/.{2}/g).join(options.delimiter);
    }
    return hex;
  } else if(options.encoding === 'binary') {
    return digest.getBytes();
  } else if(options.encoding) {
    throw new Error('Unknown encoding "' + options.encoding + '".');
  }
  return digest;
};

/**
 * Adds len(val) then val to a buffer.
 *
 * @param buffer the buffer to add to.
 * @param val a big integer.
 */
function _addBigIntegerToBuffer(buffer, val) {
  var hexVal = val.toString(16);
  // ensure 2s complement +ve
  if(hexVal[0] >= '8') {
    hexVal = '00' + hexVal;
  }
  var bytes = forge.util.hexToBytes(hexVal);
  buffer.putInt32(bytes.length);
  buffer.putBytes(bytes);
}

/**
 * Adds len(val) then val to a buffer.
 *
 * @param buffer the buffer to add to.
 * @param val a string.
 */
function _addStringToBuffer(buffer, val) {
  buffer.putInt32(val.length);
  buffer.putString(val);
}

/**
 * Hashes the arguments into one value using SHA-1.
 *
 * @return the sha1 hash of the provided arguments.
 */
function _sha1() {
  var sha = forge.md.sha1.create();
  var num = arguments.length;
  for (var i = 0; i < num; ++i) {
    sha.update(arguments[i]);
  }
  return sha.digest();
}

license: mit