helpers/peertubeCrypto.js

   1 'use strict'
   2
   3 var config = require('config')
   4 var crypto = require('crypto')
   5 var fs = require('fs')
   6 var openssl = require('openssl-wrapper')
   7 var path = require('path')
   8 var ursa = require('ursa')
   9
  10 var logger = require('./logger')
  11
  12 var certDir = path.join(__dirname, '..', config.get('storage.certs'))
  13 var algorithm = 'aes-256-ctr'
  14
  15 var peertubeCrypto = {
  16   checkSignature: checkSignature,
  17   createCertsIfNotExist: createCertsIfNotExist,
  18   decrypt: decrypt,
  19   encrypt: encrypt,
  20   getCertDir: getCertDir,
  21   sign: sign
  22 }
  23
  24 function checkSignature (public_key, raw_data, hex_signature) {
  25   var crt = ursa.createPublicKey(public_key)
  26   var is_valid = crt.hashAndVerify('sha256', new Buffer(raw_data).toString('hex'), hex_signature, 'hex')
  27   return is_valid
  28 }
  29
  30 function createCertsIfNotExist (callback) {
  31   certsExist(function (exist) {
  32     if (exist === true) {
  33       return callback(null)
  34     }
  35
  36     createCerts(function (err) {
  37       return callback(err)
  38     })
  39   })
  40 }
  41
  42 function decrypt (key, data, callback) {
  43   fs.readFile(getCertDir() + 'peertube.key.pem', function (err, file) {
  44     if (err) return callback(err)
  45
  46     var my_private_key = ursa.createPrivateKey(file)
  47     var decrypted_key = my_private_key.decrypt(key, 'hex', 'utf8')
  48     var decrypted_data = symetricDecrypt(data, decrypted_key)
  49
  50     return callback(null, decrypted_data)
  51   })
  52 }
  53
  54 function encrypt (public_key, data, callback) {
  55   var crt = ursa.createPublicKey(public_key)
  56
  57   symetricEncrypt(data, function (err, dataEncrypted) {
  58     if (err) return callback(err)
  59
  60     var key = crt.encrypt(dataEncrypted.password, 'utf8', 'hex')
  61     var encrypted = {
  62       data: dataEncrypted.crypted,
  63       key: key
  64     }
  65
  66     callback(null, encrypted)
  67   })
  68 }
  69
  70 function getCertDir () {
  71   return certDir
  72 }
  73
  74 function sign (data) {
  75   var myKey = ursa.createPrivateKey(fs.readFileSync(certDir + 'peertube.key.pem'))
  76   var signature = myKey.hashAndSign('sha256', data, 'utf8', 'hex')
  77
  78   return signature
  79 }
  80
  81 // ---------------------------------------------------------------------------
  82
  83 module.exports = peertubeCrypto
  84
  85 // ---------------------------------------------------------------------------
  86
  87 function certsExist (callback) {
  88   fs.exists(certDir + 'peertube.key.pem', function (exists) {
  89     return callback(exists)
  90   })
  91 }
  92
  93 function createCerts (callback) {
  94   certsExist(function (exist) {
  95     if (exist === true) {
  96       var string = 'Certs already exist.'
  97       logger.warning(string)
  98       return callback(new Error(string))
  99     }
 100
 101     logger.info('Generating a RSA key...')
 102     openssl.exec('genrsa', { 'out': certDir + 'peertube.key.pem', '2048': false }, function (err) {
 103       if (err) {
 104         logger.error('Cannot create private key on this pod.')
 105         return callback(err)
 106       }
 107       logger.info('RSA key generated.')
 108
 109       logger.info('Manage public key...')
 110       openssl.exec('rsa', { 'in': certDir + 'peertube.key.pem', 'pubout': true, 'out': certDir + 'peertube.pub' }, function (err) {
 111         if (err) {
 112           logger.error('Cannot create public key on this pod.')
 113           return callback(err)
 114         }
 115
 116         logger.info('Public key managed.')
 117         return callback(null)
 118       })
 119     })
 120   })
 121 }
 122
 123 function generatePassword (callback) {
 124   crypto.randomBytes(32, function (err, buf) {
 125     if (err) return callback(err)
 126
 127     callback(null, buf.toString('utf8'))
 128   })
 129 }
 130
 131 function symetricDecrypt (text, password) {
 132   var decipher = crypto.createDecipher(algorithm, password)
 133   var dec = decipher.update(text, 'hex', 'utf8')
 134   dec += decipher.final('utf8')
 135   return dec
 136 }
 137
 138 function symetricEncrypt (text, callback) {
 139   generatePassword(function (err, password) {
 140     if (err) return callback(err)
 141
 142     var cipher = crypto.createCipher(algorithm, password)
 143     var crypted = cipher.update(text, 'utf8', 'hex')
 144     crypted += cipher.final('hex')
 145     callback(null, { crypted: crypted, password: password })
 146   })
 147 }