<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>JSDoc: Source: crypto/crypto.js</title>
    
    <script src="scripts/prettify/prettify.js"> </script>
    <script src="scripts/prettify/lang-css.js"> </script>
    <!--[if lt IE 9]>
      <script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
    <![endif]-->
    <link type="text/css" rel="stylesheet" href="styles/prettify-tomorrow.css">
    <link type="text/css" rel="stylesheet" href="styles/jsdoc-default.css">
</head>

<body>

<div id="main">
    
    <h1 class="page-title">Source: crypto/crypto.js</h1>
    
    


    
    <section>
        <article>
            <pre class="prettyprint source"><code>// GPG4Browsers - An OpenPGP implementation in javascript
// Copyright (C) 2011 Recurity Labs GmbH
// 
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 

// The GPG4Browsers crypto interface

/**
 * @requires crypto/cipher
 * @requires crypto/public_key
 * @requires crypto/random
 * @requires type/mpi
 * @module crypto/crypto
 */

var random = require('./random.js'),
  cipher = require('./cipher'),
  publicKey = require('./public_key'),
  type_mpi = require('../type/mpi.js');

module.exports = {
  /**
   * Encrypts data using the specified public key multiprecision integers 
   * and the specified algorithm.
   * @param {module:enums.publicKey} algo Algorithm to be used (See {@link http://tools.ietf.org/html/rfc4880#section-9.1|RFC 4880 9.1})
   * @param {Array&lt;module:type/mpi>} publicMPIs Algorithm dependent multiprecision integers
   * @param {module:type/mpi} data Data to be encrypted as MPI
   * @return {Array&lt;module:type/mpi>} if RSA an module:type/mpi; 
   * if elgamal encryption an array of two module:type/mpi is returned; otherwise null
   */
  publicKeyEncrypt: function(algo, publicMPIs, data) {
    var result = (function() {
      var m;
      switch (algo) {
        case 'rsa_encrypt':
        case 'rsa_encrypt_sign':
          var rsa = new publicKey.rsa();
          var n = publicMPIs[0].toBigInteger();
          var e = publicMPIs[1].toBigInteger();
          m = data.toBigInteger();
          return [rsa.encrypt(m, e, n)];

        case 'elgamal':
          var elgamal = new publicKey.elgamal();
          var p = publicMPIs[0].toBigInteger();
          var g = publicMPIs[1].toBigInteger();
          var y = publicMPIs[2].toBigInteger();
          m = data.toBigInteger();
          return elgamal.encrypt(m, g, p, y);

        default:
          return [];
      }
    })();

    return result.map(function(bn) {
      var mpi = new type_mpi();
      mpi.fromBigInteger(bn);
      return mpi;
    });
  },

  /**
   * Decrypts data using the specified public key multiprecision integers of the private key,
   * the specified secretMPIs of the private key and the specified algorithm.
   * @param {module:enums.publicKey} algo Algorithm to be used (See {@link http://tools.ietf.org/html/rfc4880#section-9.1|RFC 4880 9.1})
   * @param {Array&lt;module:type/mpi>} publicMPIs Algorithm dependent multiprecision integers 
   * of the public key part of the private key
   * @param {Array&lt;module:type/mpi>} secretMPIs Algorithm dependent multiprecision integers 
   * of the private key used
   * @param {module:type/mpi} data Data to be encrypted as MPI
   * @return {module:type/mpi} returns a big integer containing the decrypted data; otherwise null
   */

  publicKeyDecrypt: function(algo, keyIntegers, dataIntegers) {
    var p;

    var bn = (function() {
      switch (algo) {
        case 'rsa_encrypt_sign':
        case 'rsa_encrypt':
          var rsa = new publicKey.rsa();
          // 0 and 1 are the public key.
          var d = keyIntegers[2].toBigInteger();
          p = keyIntegers[3].toBigInteger();
          var q = keyIntegers[4].toBigInteger();
          var u = keyIntegers[5].toBigInteger();
          var m = dataIntegers[0].toBigInteger();
          return rsa.decrypt(m, d, p, q, u);
        case 'elgamal':
          var elgamal = new publicKey.elgamal();
          var x = keyIntegers[3].toBigInteger();
          var c1 = dataIntegers[0].toBigInteger();
          var c2 = dataIntegers[1].toBigInteger();
          p = keyIntegers[0].toBigInteger();
          return elgamal.decrypt(c1, c2, p, x);
        default:
          return null;
      }
    })();

    var result = new type_mpi();
    result.fromBigInteger(bn);
    return result;
  },

  /** Returns the number of integers comprising the private key of an algorithm
   * @param {String} algo The public key algorithm
   * @return {Integer} The number of integers.
   */
  getPrivateMpiCount: function(algo) {
    switch (algo) {
      case 'rsa_encrypt':
      case 'rsa_encrypt_sign':
      case 'rsa_sign':
        //   Algorithm-Specific Fields for RSA secret keys:
        //   - multiprecision integer (MPI) of RSA secret exponent d.
        //   - MPI of RSA secret prime value p.
        //   - MPI of RSA secret prime value q (p &lt; q).
        //   - MPI of u, the multiplicative inverse of p, mod q.
        return 4;
      case 'elgamal':
        // Algorithm-Specific Fields for Elgamal secret keys:
        //   - MPI of Elgamal secret exponent x.
        return 1;
      case 'dsa':
        // Algorithm-Specific Fields for DSA secret keys:
        //   - MPI of DSA secret exponent x.
        return 1;
      default:
        throw new Error('Unknown algorithm');
    }
  },

  getPublicMpiCount: function(algo) {
    // - A series of multiprecision integers comprising the key material:
    //   Algorithm-Specific Fields for RSA public keys:
    //       - a multiprecision integer (MPI) of RSA public modulus n;
    //       - an MPI of RSA public encryption exponent e.
    switch (algo) {
      case 'rsa_encrypt':
      case 'rsa_encrypt_sign':
      case 'rsa_sign':
        return 2;

        //   Algorithm-Specific Fields for Elgamal public keys:
        //     - MPI of Elgamal prime p;
        //     - MPI of Elgamal group generator g;
        //     - MPI of Elgamal public key value y (= g**x mod p where x  is secret).
      case 'elgamal':
        return 3;

        //   Algorithm-Specific Fields for DSA public keys:
        //       - MPI of DSA prime p;
        //       - MPI of DSA group order q (q is a prime divisor of p-1);
        //       - MPI of DSA group generator g;
        //       - MPI of DSA public-key value y (= g**x mod p where x  is secret).
      case 'dsa':
        return 4;

      default:
        throw new Error('Unknown algorithm.');
    }
  },

  generateMpi: function(algo, bits) {
    var result = (function() {
      switch (algo) {
        case 'rsa_encrypt':
        case 'rsa_encrypt_sign':
        case 'rsa_sign':
          //remember "publicKey" refers to the crypto/public_key dir
          var rsa = new publicKey.rsa();
          var keyObject = rsa.generate(bits, "10001");
          var output = [];
          output.push(keyObject.n);
          output.push(keyObject.ee);
          output.push(keyObject.d);
          output.push(keyObject.p);
          output.push(keyObject.q);
          output.push(keyObject.u);
          return output;
        default:
          throw new Error('Unsupported algorithm for key generation.');
      }
    })();

    return result.map(function(bn) {
      var mpi = new type_mpi();
      mpi.fromBigInteger(bn);
      return mpi;
    });
  },


  /**
   * generate random byte prefix as string for the specified algorithm
   * @param {module:enums.symmetric} algo Algorithm to use (see {@link http://tools.ietf.org/html/rfc4880#section-9.2|RFC 4880 9.2})
   * @return {String} Random bytes with length equal to the block
   * size of the cipher
   */
  getPrefixRandom: function(algo) {
    return random.getRandomBytes(cipher[algo].blockSize);
  },

  /**
   * Generating a session key for the specified symmetric algorithm
   * @param {module:enums.symmetric} algo Algorithm to use (see {@link http://tools.ietf.org/html/rfc4880#section-9.2|RFC 4880 9.2})
   * @return {String} Random bytes as a string to be used as a key
   */
  generateSessionKey: function(algo) {
    return random.getRandomBytes(cipher[algo].keySize);
  }
};
</code></pre>
        </article>
    </section>




</div>

<nav>
    <h2><a href="index.html">Index</a></h2><h3>Modules</h3><ul><li><a href="module-cleartext.html">cleartext</a></li><li><a href="module-config.html">config</a></li><li><a href="config.html">config/config</a></li><li><a href="localStorage.html">config/localStorage</a></li><li><a href="module-crypto.html">crypto</a></li><li><a href="cfb.html">crypto/cfb</a></li><li><a href="cipher.html">crypto/cipher</a></li><li><a href="aes.html">crypto/cipher/aes</a></li><li><a href="blowfish.html">crypto/cipher/blowfish</a></li><li><a href="cast5.html">crypto/cipher/cast5</a></li><li><a href="des.html">crypto/cipher/des</a></li><li><a href="twofish.html">crypto/cipher/twofish</a></li><li><a href="crypto.html">crypto/crypto</a></li><li><a href="hash.html">crypto/hash</a></li><li><a href="md5.html">crypto/hash/md5</a></li><li><a href="ripe-md.html">crypto/hash/ripe-md</a></li><li><a href="sha.html">crypto/hash/sha</a></li><li><a href="pkcs1.html">crypto/pkcs1</a></li><li><a href="public_key.html">crypto/public_key</a></li><li><a href="dsa.html">crypto/public_key/dsa</a></li><li><a href="elgamal.html">crypto/public_key/elgamal</a></li><li><a href="jsbn.html">crypto/public_key/jsbn</a></li><li><a href="rsa.html">crypto/public_key/rsa</a></li><li><a href="random.html">crypto/random</a></li><li><a href="signature.html">crypto/signature</a></li><li><a href="armor.html">encoding/armor</a></li><li><a href="base64.html">encoding/base64</a></li><li><a href="module-enums.html">enums</a></li><li><a href="module-key.html">key</a></li><li><a href="module-keyring.html">keyring</a></li><li><a href="keyring.html">keyring/keyring</a></li><li><a href="localstore.html">keyring/localstore</a></li><li><a href="module-message.html">message</a></li><li><a href="module-openpgp.html">openpgp</a></li><li><a href="module-packet.html">packet</a></li><li><a href="compressed.html">packet/compressed</a></li><li><a href="literal.html">packet/literal</a></li><li><a href="marker.html">packet/marker</a></li><li><a href="one_pass_signature.html">packet/one_pass_signature</a></li><li><a href="packet.html">packet/packet</a></li><li><a href="packetlist.html">packet/packetlist</a></li><li><a href="public_key_.html">packet/public_key</a></li><li><a href="public_key_encrypted_session_key.html">packet/public_key_encrypted_session_key</a></li><li><a href="public_subkey.html">packet/public_subkey</a></li><li><a href="secret_key.html">packet/secret_key</a></li><li><a href="secret_subkey.html">packet/secret_subkey</a></li><li><a href="signature_.html">packet/signature</a></li><li><a href="sym_encrypted_integrity_protected.html">packet/sym_encrypted_integrity_protected</a></li><li><a href="sym_encrypted_session_key.html">packet/sym_encrypted_session_key</a></li><li><a href="symmetrically_encrypted.html">packet/symmetrically_encrypted</a></li><li><a href="trust.html">packet/trust</a></li><li><a href="user_attribute.html">packet/user_attribute</a></li><li><a href="userid.html">packet/userid</a></li><li><a href="keyid.html">type/keyid</a></li><li><a href="mpi.html">type/mpi</a></li><li><a href="s2k.html">type/s2k</a></li><li><a href="module-util.html">util</a></li></ul><h3>Classes</h3><ul><li><a href="JXG.Util.html">JXG.Util</a></li><li><a href="module-cleartext-CleartextMessage.html">cleartext~CleartextMessage</a></li><li><a href="localStorage-LocalStorage.html">config/localStorage~LocalStorage</a></li><li><a href="keyring-Keyring.html">keyring/keyring~Keyring</a></li><li><a href="module-key-Key.html">key~Key</a></li><li><a href="module-key-SubKey.html">key~SubKey</a></li><li><a href="module-key-User.html">key~User</a></li><li><a href="module-message-Message.html">message~Message</a></li><li><a href="compressed-Compressed.html">packet/compressed~Compressed</a></li><li><a href="literal-Literal.html">packet/literal~Literal</a></li><li><a href="marker-Marker.html">packet/marker~Marker</a></li><li><a href="one_pass_signature-OnePassSignature.html">packet/one_pass_signature~OnePassSignature</a></li><li><a href="packetlist-Packetlist.html">packet/packetlist~Packetlist</a></li><li><a href="public_key_encrypted_session_key-PublicKeyEncryptedSessionKey.html">packet/public_key_encrypted_session_key~PublicKeyEncryptedSessionKey</a></li><li><a href="public_key-PublicKey.html">packet/public_key~PublicKey</a></li><li><a href="public_subkey-PublicSubkey.html">packet/public_subkey~PublicSubkey</a></li><li><a href="secret_key-SecretKey.html">packet/secret_key~SecretKey</a></li><li><a href="secret_subkey-SecretSubkey.html">packet/secret_subkey~SecretSubkey</a></li><li><a href="signature-Signature.html">packet/signature~Signature</a></li><li><a href="sym_encrypted_integrity_protected-SymEncryptedIntegrityProtected.html">packet/sym_encrypted_integrity_protected~SymEncryptedIntegrityProtected</a></li><li><a href="sym_encrypted_session_key-SymEncryptedSessionKey.html">packet/sym_encrypted_session_key~SymEncryptedSessionKey</a></li><li><a href="symmetrically_encrypted-SymmetricallyEncrypted.html">packet/symmetrically_encrypted~SymmetricallyEncrypted</a></li><li><a href="trust-Trust.html">packet/trust~Trust</a></li><li><a href="user_attribute-UserAttribute.html">packet/user_attribute~UserAttribute</a></li><li><a href="userid-Userid.html">packet/userid~Userid</a></li><li><a href="keyid-Keyid.html">type/keyid~Keyid</a></li><li><a href="mpi-MPI.html">type/mpi~MPI</a></li><li><a href="s2k-S2K.html">type/s2k~S2K</a></li></ul>
</nav>

<br clear="both">

<footer>
    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.2.2</a> on Thu Jan 09 2014 02:24:28 GMT-0800 (PST)
</footer>

<script> prettyPrint(); </script>
<script src="scripts/linenumber.js"> </script>
</body>
</html>