chore: Add ajv dependency and refactor server startup code

app/app.js

@@ -6,30 +6,85 @@ const socketIo = require('socket.io')
 const config = require('./config')
 const socketHandler = require('./socket')
 
-const server = http.createServer()
+/**
+ * Creates and configures the HTTP server
+ * @returns {http.Server} The HTTP server instance
+ */
+function createServer() {
+  return http.createServer()
+}
 
-const io = socketIo(server, {
+/**
-  path: '/ssh/socket.io',
+ * Configures Socket.IO with the given server
-  cors: {
+ * @param {http.Server} server - The HTTP server instance
-    origin: config.origin || ["*.*"],
+ * @returns {import('socket.io').Server} The Socket.IO server instance
+ */
+function configureSocketIO(server) {
+  return socketIo(server, {
+    path: '/ssh/socket.io',
+    cors: getCorsConfig()
+  })
+}
+
+/**
+ * Gets the CORS configuration
+ * @returns {Object} The CORS configuration object
+ */
+function getCorsConfig() {
+  return {
+    origin: config.origin || ['*.*'],
     methods: ['GET', 'POST'],
     credentials: true
   }
-})
+}
 
-io.on('connection', (socket) => {
+/**
+ * Sets up Socket.IO event listeners
+ * @param {import('socket.io').Server} io - The Socket.IO server instance
+ */
+function setupSocketIOListeners(io) {
+  socketHandler(io, config)
+}
+
+/**
+ * Handles a new Socket.IO connection
+ * @param {import('socket.io').Socket} socket - The Socket.IO socket
+ */
+function handleConnection(socket) {
+  logNewConnection(socket)
+  setupDisconnectListener(socket)
+}
+
+/**
+ * Logs information about a new connection
+ * @param {import('socket.io').Socket} socket - The Socket.IO socket
+ */
+function logNewConnection(socket) {
   console.log(
     'New connection:',
     socket.id,
     'Transport:',
     socket.conn.transport.name
   )
+}
 
-  socketHandler(io, socket)
+/**
-
+ * Sets up the disconnect listener for a socket
+ * @param {import('socket.io').Socket} socket - The Socket.IO socket
+ */
+function setupDisconnectListener(socket) {
   socket.on('disconnect', (reason) => {
     console.log('Client disconnected:', socket.id, reason)
   })
-})
+}
+
+// Create and configure the server
+const server = createServer()
+const io = configureSocketIO(server)
+
+// Set up Socket.IO listeners
+setupSocketIOListeners(io)
+
+// Log the config object to verify its contents
 
 module.exports = { server, config, io }

app/config.js

@@ -1,11 +1,55 @@
-// config.js
+'use strict'
+
 const path = require('path')
 const fs = require('fs')
-const nodeRoot = path.dirname(require.main.filename)
+const readConfig = require('read-config-ng')
-const configPath = path.join(nodeRoot, 'config.json')
+const Ajv = require('ajv')
 
-// Default configuration
+/**
-let config = {
+ * @typedef {Object} Config
+ * @property {Object} listen - Listening configuration
+ * @property {string} listen.ip - IP address to listen on
+ * @property {number} listen.port - Port to listen on
+ * @property {Object} http - HTTP configuration
+ * @property {string[]} http.origins - Allowed origins
+ * @property {Object} user - User configuration
+ * @property {string|null} user.name - Username
+ * @property {string|null} user.password - Password
+ * @property {Object} ssh - SSH configuration
+ * @property {string|null} ssh.host - SSH host
+ * @property {number} ssh.port - SSH port
+ * @property {string} ssh.term - Terminal type
+ * @property {number} ssh.readyTimeout - Ready timeout
+ * @property {number} ssh.keepaliveInterval - Keepalive interval
+ * @property {number} ssh.keepaliveCountMax - Max keepalive count
+ * @property {Object} terminal - Terminal configuration
+ * @property {boolean} terminal.cursorBlink - Whether cursor blinks
+ * @property {number} terminal.scrollback - Scrollback limit
+ * @property {number} terminal.tabStopWidth - Tab stop width
+ * @property {string} terminal.bellStyle - Bell style
+ * @property {Object} header - Header configuration
+ * @property {string|null} header.text - Header text
+ * @property {string} header.background - Header background color
+ * @property {Object} options - Options configuration
+ * @property {boolean} options.challengeButton - Challenge button enabled
+ * @property {boolean} options.allowreauth - Allow reauthentication
+ * @property {Object} algorithms - Encryption algorithms
+ * @property {string[]} algorithms.kex - Key exchange algorithms
+ * @property {string[]} algorithms.cipher - Cipher algorithms
+ * @property {string[]} algorithms.hmac - HMAC algorithms
+ * @property {string[]} algorithms.compress - Compression algorithms
+ * @property {Object} serverlog - Server log configuration
+ * @property {boolean} serverlog.client - Client logging enabled
+ * @property {boolean} serverlog.server - Server logging enabled
+ * @property {boolean} accesslog - Access logging enabled
+ * @property {boolean} verify - Verification enabled
+ */
+
+/**
+ * Default configuration
+ * @type {Config}
+ */
+const defaultConfig = {
   listen: {
     ip: '0.0.0.0',
     port: 2222
@@ -37,7 +81,8 @@ let config = {
   },
   options: {
     challengeButton: true,
-    allowreauth: true
+    allowreauth: false,
+    allowReplay: false
   },
   algorithms: {
     kex: [
@@ -68,24 +113,196 @@ let config = {
   verify: false
 }
 
-try {
+/**
-  if (fs.existsSync(configPath)) {
+ * Schema for validating the config
-    console.log('WebSSH2 service reading config from: ' + configPath)
+ */
-    config = require('read-config-ng')(configPath)
+const configSchema = {
-  } else {
+  type: 'object',
-    console.error(
+  properties: {
-      '\n\nERROR: Missing config.json for webssh. Current config: ' +
+    listen: {
-        JSON.stringify(config)
+      type: 'object',
-    )
+      properties: {
-    console.error('\n  See config.json.sample for details\n\n')
+        ip: { type: 'string', format: 'ipv4' },
-  }
+        port: { type: 'integer', minimum: 1, maximum: 65535 }
-} catch (err) {
+      },
-  console.error(
+      required: ['ip', 'port']
-    '\n\nERROR: Missing config.json for webssh. Current config: ' +
+    },
-      JSON.stringify(config)
+    http: {
-  )
+      type: 'object',
-  console.error('\n  See config.json.sample for details\n\n')
+      properties: {
-  console.error('ERROR:\n\n  ' + err)
+        origins: {
+          type: 'array',
+          items: { type: 'string' }
+        }
+      },
+      required: ['origins']
+    },
+    user: {
+      type: 'object',
+      properties: {
+        name: { type: ['string', 'null'] },
+        password: { type: ['string', 'null'] }
+      },
+      required: ['name', 'password']
+    },
+    ssh: {
+      type: 'object',
+      properties: {
+        host: { type: ['string', 'null'] },
+        port: { type: 'integer', minimum: 1, maximum: 65535 },
+        term: { type: 'string' },
+        readyTimeout: { type: 'integer' },
+        keepaliveInterval: { type: 'integer' },
+        keepaliveCountMax: { type: 'integer' }
+      },
+      required: ['host', 'port', 'term', 'readyTimeout', 'keepaliveInterval', 'keepaliveCountMax']
+    },
+    terminal: {
+      type: 'object',
+      properties: {
+        cursorBlink: { type: 'boolean' },
+        scrollback: { type: 'integer' },
+        tabStopWidth: { type: 'integer' },
+        bellStyle: { type: 'string' }
+      },
+      required: ['cursorBlink', 'scrollback', 'tabStopWidth', 'bellStyle']
+    },
+    header: {
+      type: 'object',
+      properties: {
+        text: { type: ['string', 'null'] },
+        background: { type: 'string' }
+      },
+      required: ['text', 'background']
+    },
+    options: {
+      type: 'object',
+      properties: {
+        challengeButton: { type: 'boolean' },
+        allowreauth: { type: 'boolean' },
+        allowReplay: { type: 'boolean' }
+      },
+      required: ['challengeButton', 'allowreauth', 'allowReplay']
+    },
+    algorithms: {
+      type: 'object',
+      properties: {
+        kex: {
+          type: 'array',
+          items: { type: 'string' }
+        },
+        cipher: {
+          type: 'array',
+          items: { type: 'string' }
+        },
+        hmac: {
+          type: 'array',
+          items: { type: 'string' }
+        },
+        compress: {
+          type: 'array',
+          items: { type: 'string' }
+        }
+      },
+      required: ['kex', 'cipher', 'hmac', 'compress']
+    },
+    serverlog: {
+      type: 'object',
+      properties: {
+        client: { type: 'boolean' },
+        server: { type: 'boolean' }
+      },
+      required: ['client', 'server']
+    },
+    accesslog: { type: 'boolean' },
+    verify: { type: 'boolean' }
+  },
+  required: ['listen', 'http', 'user', 'ssh', 'terminal', 'header', 'options', 'algorithms', 'serverlog', 'accesslog', 'verify']
 }
 
+/**
+ * Gets the path to the config file
+ * @returns {string} The path to the config file
+ */
+function getConfigPath() {
+  const nodeRoot = path.dirname(require.main.filename)
+  return path.join(nodeRoot, 'config.json')
+}
+
+/**
+ * Reads the config file
+ * @param {string} configPath - The path to the config file
+ * @returns {Config} The configuration object
+ */
+function readConfigFile(configPath) {
+  console.log('WebSSH2 service reading config from: ' + configPath)
+  return readConfig(configPath)
+}
+
+/**
+ * Validates the configuration against the schema
+ * @param {Object} config - The configuration object to validate
+ * @returns {Object} The validated configuration object
+ * @throws {Error} If the configuration is invalid
+ */
+function validateConfig(config) {
+  const ajv = new Ajv()
+  const validate = ajv.compile(configSchema)
+  const valid = validate(config)
+  console.log('WebSSH2 service validating config')
+  if (!valid) {
+    throw new Error('Config validation error: ' + ajv.errorsText(validate.errors))
+  }
+  console.log("config: ", JSON.stringify(config, null, 2))
+  return config
+}
+
+/**
+ * Logs an error message
+ * @param {string} message - The error message
+ * @param {Error} [error] - The error object
+ */
+function logError(message, error) {
+  console.error(message)
+  if (error) {
+    console.error('ERROR:\n\n  ' + error)
+  }
+}
+
+/**
+ * Loads the configuration
+ * @returns {Config} The loaded configuration
+ */
+function loadConfig() {
+  const configPath = getConfigPath()
+
+  try {
+    if (fs.existsSync(configPath)) {
+      const config = readConfigFile(configPath)
+      return validateConfig(config)
+    } else {
+      logError(
+        '\n\nERROR: Missing config.json for webssh. Current config: ' +
+          JSON.stringify(defaultConfig) +
+          '\n\n  See config.json.sample for details\n\n'
+      )
+      return defaultConfig
+    }
+  } catch (err) {
+    logError(
+      '\n\nERROR: Missing config.json for webssh. Current config: ' +
+        JSON.stringify(defaultConfig) +
+        '\n\n  See config.json.sample for details\n\n',
+      err
+    )
+    return defaultConfig
+  }
+}
+
+/**
+ * The loaded configuration
+ * @type {Config}
+ */
+const config = loadConfig()
+
 module.exports = config

app/socket.js

@@ -5,142 +5,316 @@ const debug = require('debug')
 const debugWebSSH2 = require('debug')('WebSSH2')
 const SSH = require('ssh2').Client
 
-module.exports = function (io) {
+let conn = null;
-  io.on('connection', (socket) => {
+let stream = null;
-    let conn = null
-    let stream = null
-    console.log(`SOCKET CONNECT: ${socket.id}`)
 
-    // Remove existing listeners to prevent duplicates
+/**
-    socket.removeAllListeners('authenticate')
+ * Handles WebSocket connections for SSH
-    socket.removeAllListeners('data')
+ * @param {import('socket.io').Server} io - The Socket.IO server instance
-    socket.removeAllListeners('resize')
+ * @param {Object} config - The configuration object
-    socket.removeAllListeners('disconnect')
+ */
-
+module.exports = function (io, config) {
-    // Authenticate user
+  io.on('connection', (socket) => handleConnection(socket, config))
-    socket.on('authenticate', (credentials) => {
+}
-      console.log(`SOCKET AUTHENTICATE: ${socket.id}`)
+
-      if (isValidCredentials(credentials)) {
+/**
-        console.log(`SOCKET AUTHENTICATE SUCCESS: ${socket.id}`)
+ * Handles a new WebSocket connection
-        initializeConnection(socket, credentials)
+ * @param {import('socket.io').Socket} socket - The Socket.IO socket
-      } else {
+ * @param {Object} config - The configuration object
-        console.log(`SOCKET AUTHENTICATE FAILED: ${socket.id}`)
+ */
-        socket.emit('auth_result', {
+function handleConnection(socket, config) {
-          success: false,
+  let isConnectionClosed = false;
-          message: 'Invalid credentials'
+
-        })
+  console.log(`SOCKET CONNECT: ${socket.id}`);
-      }
+
-    })
+  removeExistingListeners(socket)
-
+  setupInitialSocketListeners(socket, config)
-    socket.on('disconnect', (reason) => {
+
-      debugWebSSH2(`SOCKET DISCONNECT: ${socket.id}, Reason: ${reason}`)
+  /**
-      if (conn) {
+   * Removes existing listeners to prevent duplicates
-        conn.end()
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
-      }
+   */
-      // Clean up listeners
+  function removeExistingListeners(socket) {
-      socket.removeAllListeners()
+    ['authenticate', 'data', 'resize', 'disconnect', 'control'].forEach(event => {
-    })
+      socket.removeAllListeners(event)
-
+    })
-    socket.on('data', (data) => {
+  }
-      if (stream) {
+
-        stream.write(data)
+  /**
-      }
+   * Sets up initial socket event listeners
-    })
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
-
+   * @param {Object} config - The configuration object
-    socket.on('resize', (data) => {
+   */
-      if (stream) {
+  function setupInitialSocketListeners(socket, config) {
-        stream.setWindow(data.rows, data.cols)
+    socket.on('authenticate', creds => handleAuthentication(socket, creds, config))
-      }
+    socket.on('disconnect', reason => handleDisconnect(socket, reason))
-    })
+  }
-
+
-    function initializeConnection (socket, credentials) {
+  /**
-      if (conn) {
+   * Handles authentication attempts
-        // If there's an existing connection, end it before creating a new one
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
-        conn.end()
+   * @param {Credentials} creds - The credentials for authentication
-      }
+   * @param {Object} config - The configuration object
-
+   */
-      conn = new SSH()
+  function handleAuthentication(socket, creds, config) {
-
+    console.log(`SOCKET AUTHENTICATE: ${socket.id}`)
-      conn.on('ready', () => {
+    if (isValidCredentials(creds)) {
-        console.log(
+      console.log(`SOCKET AUTHENTICATE SUCCESS: ${socket.id}`)
-          `WebSSH2 Login: user=${credentials.username} from=${socket.handshake.address} host=${credentials.host} port=${credentials.port} sessionID=${socket.id}`
+      initializeConnection(socket, creds, config)
-        )
+    } else {
-
+      console.log(`SOCKET AUTHENTICATE FAILED: ${socket.id}`)
-        socket.emit('auth_result', { success: true })
+      socket.emit('auth_result', { success: false, message: 'Invalid credentials' })
-        socket.emit('allowreauth', true)
+    }
-        socket.emit('allowreplay', true)
+  }
-        socket.emit('title', `ssh://${credentials.host}`)
+
-        socket.emit('status', 'SSH CONNECTION ESTABLISHED')
+  /**
-        socket.emit('statusBackground', 'green')
+   * Initializes an SSH connection
-
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
-        conn.shell(
+   * @param {Credentials} creds - The user credentials
-          {
+   * @param {Object} config - The configuration object
-            term: credentials.term,
+   */
-            cols: credentials.cols,
+  function initializeConnection(socket, creds, config) {
-            rows: credentials.rows
+    if (conn) {
-          },
+      conn.end()
-          (err, str) => {
+    }
-            if (err) {
+
-              return SSHerror('EXEC ERROR', err)
+    conn = new SSH()
-            }
+
-            stream = str
+    conn.on('ready', () => {
-
+      console.log(`SSH CONNECTION READY: ${socket.id}`)
-            stream.on('data', (data) => {
+      socket.emit('auth_result', { success: true })
-              socket.emit('data', data.toString('utf-8'))
+      socket.emit('allowreplay', config.options.allowReplay || false)
-            })
+      socket.emit('allowreauth', config.options.allowreauth || false)
-
+      setupSSHListeners(socket, creds)
-            stream.on('close', (code, signal) => {
+      initializeShell(socket, creds)
-              SSHerror('STREAM CLOSE', {
+    })
-                message:
+
-                  code || signal
+    conn.on('error', err => {
-                    ? `CODE: ${code} SIGNAL: ${signal}`
+      console.log(`SSH CONNECTION ERROR: ${socket.id}`, err)
-                    : undefined
+      handleError(socket, 'SSH CONNECTION ERROR', err)
-              })
+    })
-            })
+
-
+    conn.connect(getSSHConfig(creds, config))
-            stream.stderr.on('data', (data) => {
+  }
-              console.log('STDERR: ' + data)
+
-            })
+  /**
-          }
+   * Sets up SSH-specific event listeners
-        )
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
-      })
+   * @param {Credentials} creds - The user credentials
-
+   */
-      conn.on('banner', (data) => {
+  function setupSSHListeners(socket, creds) {
-        socket.emit('data', data.replace(/\r?\n/g, '\r\n'))
+    conn.on('banner', data => handleBanner(socket, data))
-      })
+    conn.on('end', () => handleSSHEnd(socket))
-
+    conn.on('close', () => handleSSHClose(socket))
-      conn.on('end', () => SSHerror('CONN END BY HOST'))
+
-      conn.on('close', () => SSHerror('CONN CLOSE'))
+    socket.on('data', data => handleData(socket, stream, data))
-      conn.on('error', (err) => SSHerror('CONN ERROR', err))
+    socket.on('resize', data => handleResize(stream, data))
-
+    socket.on('control', controlData => handleControl(socket, stream, creds, controlData, config))
-      conn.connect({
+  }
-        host: credentials.host,
+
-        port: credentials.port,
+  /**
-        username: credentials.username,
+   * Initializes the SSH shell
-        password: credentials.password,
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
-        tryKeyboard: true,
+   * @param {Credentials} creds - The user credentials
-        algorithms: credentials.algorithms,
+   */
-        readyTimeout: credentials.readyTimeout,
+  function initializeShell(socket, creds) {
-        keepaliveInterval: credentials.keepaliveInterval,
+    conn.shell(
-        keepaliveCountMax: credentials.keepaliveCountMax,
+      {
-        debug: debug('ssh2')
+        term: creds.term,
-      })
+        cols: creds.cols,
-    }
+        rows: creds.rows
-
+      },
-    function SSHerror (myFunc, err) {
+      (err, str) => {
-      const errorMessage = err ? `: ${err.message}` : ''
+        if (err) {
-      console.log(`WebSSH2 error: ${myFunc}${errorMessage}`)
+          return handleError(socket, 'EXEC ERROR', err)
-      socket.emit('ssherror', `SSH ${myFunc}${errorMessage}`)
+        }
-      if (conn) {
+        stream = str
-        conn.end()
+
-      }
+        stream.on('data', data => socket.emit('data', data.toString('utf-8')))
-      // Don't disconnect the socket here, let the client handle reconnection if necessary
+        stream.on('close', (code, signal) => {
-      // socket.disconnect(true);
+          handleError(socket, 'STREAM CLOSE', {
-    }
+            message: code || signal ? `CODE: ${code} SIGNAL: ${signal}` : undefined
-
+          })
-    function isValidCredentials (credentials) {
+        })
-      // Implement your credential validation logic here
+        stream.stderr.on('data', data => console.log('STDERR: ' + data))
-      return credentials && credentials.username && credentials.password
+      }
-    }
+    )
-  })
+  }
+
+  /**
+   * Handles the 'banner' event of the SSH connection
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   * @param {string} data - The banner data
+   */
+  function handleBanner(socket, data) {
+    socket.emit('data', data.replace(/\r?\n/g, '\r\n'))
+  }
+
+  /**
+   * Handles the SSH connection end event
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   */
+  function handleSSHEnd(socket) {
+    console.log(`SSH CONNECTION ENDED: ${socket.id}`)
+    handleConnectionClose(socket)
+  }
+
+  /**
+   * Handles the SSH connection close event
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   */
+  function handleSSHClose(socket) {
+    console.log(`SSH CONNECTION CLOSED: ${socket.id}`)
+    handleConnectionClose(socket)
+  }
+
+  /**
+   * Handles the closure of the SSH connection
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   */
+  function handleConnectionClose(socket) {
+    isConnectionClosed = true
+    if (stream) {
+      stream.end()
+      stream = null
+    }
+    if (conn) {
+      conn.end()
+      conn = null
+    }
+    socket.emit('connection_closed')
+  }
+
+  /**
+   * Handles socket disconnection
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   * @param {string} reason - The reason for disconnection
+   */
+  function handleDisconnect(socket, reason) {
+    console.log(`SOCKET DISCONNECT: ${socket.id}, Reason: ${reason}`)
+    handleConnectionClose(socket)
+  }
+
+  /**
+   * Handles incoming data from the client
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   * @param {import('ssh2').Channel} stream - The SSH stream
+   * @param {string} data - The incoming data
+   */
+  function handleData(socket, stream, data) {
+    if (stream && !isConnectionClosed) {
+      try {
+        stream.write(data)
+      } catch (error) {
+        console.log('Error writing to stream:', error.message)
+        handleConnectionClose(socket)
+      }
+    } else if (isConnectionClosed) {
+      console.log('Attempted to write to closed connection')
+      socket.emit('connection_closed')
+    }
+  }
+
+  /**
+   * Handles terminal resize events
+   * @param {import('ssh2').Channel} stream - The SSH stream
+   * @param {Object} data - The resize data
+   * @param {number} data.rows - The number of rows
+   * @param {number} data.cols - The number of columns
+   */
+  function handleResize(stream, data) {
+    if (stream) {
+      stream.setWindow(data.rows, data.cols)
+    }
+  }
+
+  /**
+   * Handles control commands from the client
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   * @param {import('ssh2').Channel} stream - The SSH stream
+   * @param {Credentials} credentials - The user credentials
+   * @param {string} controlData - The control command
+   * @param {Object} config - The configuration object
+   */
+  function handleControl(socket, stream, credentials, controlData, config) {
+    console.log(`Received control data: ${controlData}`);
+  
+    if (controlData === 'replayCredentials' && stream && credentials) {
+      replayCredentials(socket, stream, credentials, config);
+    } else if (controlData === 'reauth' && config.options.allowreauth) {
+      handleReauth(socket);
+    }
+  }
+  
+  /**
+   * Replays the user credentials to the SSH stream
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   * @param {import('ssh2').Channel} stream - The SSH stream
+   * @param {Credentials} credentials - The user credentials
+   * @param {Object} config - The configuration object
+   */
+  function replayCredentials(socket, stream, credentials, config) {
+    let allowReplay = config.options.allowReplay || false;
+    
+    if (allowReplay) {
+      console.log(`Replaying credentials for ${socket.id}`);
+      stream.write(credentials.password + '\n');
+    } else {
+      console.log(`Credential replay not allowed for ${socket.id}`);
+    }
+  }
+
+  /**
+   * Handles reauthentication request
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   */
+  function handleReauth(socket) {
+    console.log(`Reauthentication requested for ${socket.id}`);
+    handleConnectionClose(socket);
+    socket.emit('reauth');
+  }
+
+  /**
+   * Handles SSH errors
+   * @param {import('socket.io').Socket} socket - The Socket.IO socket
+   * @param {string} context - The context where the error occurred
+   * @param {Error} [err] - The error object
+   */
+  function handleError(socket, context, err) {
+    const errorMessage = err ? `: ${err.message}` : ''
+    console.log(`WebSSH2 error: ${context}${errorMessage}`)
+    socket.emit('ssherror', `SSH ${context}${errorMessage}`)
+    handleConnectionClose(socket)
+  }
+
+  /**
+   * Validates the provided credentials
+   * @param {Credentials} credentials - The credentials to validate
+   * @returns {boolean} Whether the credentials are valid
+   */
+  function isValidCredentials(credentials) {
+    // Implement your credential validation logic here
+    return credentials && credentials.username && credentials.password
+  }
+
+  /**
+   * Generates the SSH configuration object
+   * @param {Credentials} credentials - The user credentials
+   * @param {Object} config - The configuration object
+   * @returns {import('ssh2').ConnectConfig} The SSH configuration object
+   */
+  function getSSHConfig(credentials, config) {
+    return {
+      host: credentials.host,
+      port: credentials.port,
+      username: credentials.username,
+      password: credentials.password,
+      tryKeyboard: true,
+      algorithms: credentials.algorithms,
+      readyTimeout: credentials.readyTimeout,
+      keepaliveInterval: credentials.keepaliveInterval,
+      keepaliveCountMax: credentials.keepaliveCountMax,
+      debug: debug('ssh2')
+    }
+  }
 }

index.js

@@ -1,20 +1,51 @@
 'use strict'
-/* jshint esversion: 6, asi: true, node: true */
+
-/*
+/**
  * index.js
  *
  * WebSSH2 - Web to SSH2 gateway
  * Bill Church - https://github.com/billchurch/WebSSH2 - May 2017
- *
  */
+
 const { server, config } = require('./app/app')
 
-server.listen(config.listen.port, config.listen.ip, () => {
+/**
-  console.log(
+ * Starts the server
-    `WebSSH2 service listening on ${config.listen.ip}:${config.listen.port}`
+ * @param {Object} config - The server configuration
-  )
+ * @param {string} config.listen.ip - The IP address to listen on
-})
+ * @param {number} config.listen.port - The port to listen on
+ * @param {import('http').Server} server - The HTTP server instance
+ */
+function startServer(config, server) {
+  server.listen(config.listen.port, config.listen.ip, () => {
+    console.log(
+      `WebSSH2 service listening on ${config.listen.ip}:${config.listen.port}`
+    )
+  })
 
-server.on('error', function (err) {
+  server.on('error', handleServerError)
-  console.log('WebSSH2 server.listen ERROR: ' + err.code)
+}
-})
+
+/**
+ * Handles server errors
+ * @param {Error} err - The error object
+ */
+function handleServerError(err) {
+  console.error('WebSSH2 server.listen ERROR:', err.code)
+}
+
+/**
+ * Main function to start the application
+ */
+function main() {
+  startServer(config, server)
+}
+
+// Run the application
+main()
+
+// For testing purposes, export the functions
+module.exports = {
+  startServer,
+  handleServerError
+}

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "webssh2-server",
-  "version": "0.2.13",
+  "version": "0.2.14",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -31,15 +31,12 @@
       "integrity": "sha512-QbJ0NTQ/I9DI3uSJA4cbexiwQeRAfjPScqIbSjUDd9TOrcg6pTkdgziesOqxBMBzit8vFCTwrP27t13vFOORRA=="
     },
     "ajv": {
-      "version": "6.12.6",
+      "version": "4.11.8",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-4.11.8.tgz",
-      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
+      "integrity": "sha512-I/bSHSNEcFFqXLf91nchoNB9D1Kie3QKcWdchYUaoIg1+1bdWDkdfdlvdIOJbi9U8xR0y+MWc5D+won9v95WlQ==",
-      "dev": true,
       "requires": {
-        "fast-deep-equal": "^3.1.1",
+        "co": "^4.6.0",
-        "fast-json-stable-stringify": "^2.0.0",
+        "json-stable-stringify": "^1.0.1"
-        "json-schema-traverse": "^0.4.1",
-        "uri-js": "^4.2.2"
       }
     },
     "ajv-keywords": {
@@ -446,7 +443,6 @@
       "version": "1.0.7",
       "resolved": "https://registry.npmjs.org/call-bind/-/call-bind-1.0.7.tgz",
       "integrity": "sha512-GHTSNSYICQ7scH7sZ+M2rFopRoLh8t2bLSW6BbgrtLsahOIB5iyAVJf9GjWK3cYTDaMj4XdBpM1cA6pIS0Kv2w==",
-      "dev": true,
       "requires": {
         "es-define-property": "^1.0.0",
         "es-errors": "^1.3.0",
@@ -580,6 +576,11 @@
       "integrity": "sha512-GRMWDxpOB6Dgk2E5Uo+3eEBvtOOlimMmpbFiKuLFnQzYDavtLFY3K5ona41jgN/WdRZtG7utuVSVTL4HbZHGkw==",
       "dev": true
     },
+    "co": {
+      "version": "4.6.0",
+      "resolved": "https://registry.npmjs.org/co/-/co-4.6.0.tgz",
+      "integrity": "sha512-QVb0dM5HvG+uaxitm8wONl7jltx8dqhfU33DcqtOZcLSVIKSDDLDi7+0LbAKiyI8hD9u42m2YxXSkMGWThaecQ=="
+    },
     "collection-visit": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/collection-visit/-/collection-visit-1.0.0.tgz",
@@ -789,7 +790,6 @@
       "version": "1.1.4",
       "resolved": "https://registry.npmjs.org/define-data-property/-/define-data-property-1.1.4.tgz",
       "integrity": "sha512-rBMvIzlpA8v6E+SJZoo++HAYqsLrkg7MSfIinMPFhmkorw7X+dOXVJQs+QT69zGkzMyfDnIMN2Wid1+NbL3T+A==",
-      "dev": true,
       "requires": {
         "es-define-property": "^1.0.0",
         "es-errors": "^1.3.0",
@@ -1015,7 +1015,6 @@
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/es-define-property/-/es-define-property-1.0.0.tgz",
       "integrity": "sha512-jxayLKShrEqqzJ0eumQbVhTYQM27CfT1T35+gCgDFoL82JLsXqTJ76zv6A0YLOgEnLUMvLzsDsGIrl8NFpT2gQ==",
-      "dev": true,
       "requires": {
         "get-intrinsic": "^1.2.4"
       }
@@ -1023,8 +1022,7 @@
     "es-errors": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/es-errors/-/es-errors-1.3.0.tgz",
-      "integrity": "sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw==",
+      "integrity": "sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw=="
-      "dev": true
     },
     "es-object-atoms": {
       "version": "1.0.0",
@@ -1109,6 +1107,18 @@
         "text-table": "^0.2.0"
       },
       "dependencies": {
+        "ajv": {
+          "version": "6.12.6",
+          "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
+          "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
+          "dev": true,
+          "requires": {
+            "fast-deep-equal": "^3.1.1",
+            "fast-json-stable-stringify": "^2.0.0",
+            "json-schema-traverse": "^0.4.1",
+            "uri-js": "^4.2.2"
+          }
+        },
         "argparse": {
           "version": "1.0.10",
           "resolved": "https://registry.npmjs.org/argparse/-/argparse-1.0.10.tgz",
@@ -1675,8 +1685,7 @@
     "function-bind": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.2.tgz",
-      "integrity": "sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==",
+      "integrity": "sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA=="
-      "dev": true
     },
     "function.prototype.name": {
       "version": "1.1.6",
@@ -1706,7 +1715,6 @@
       "version": "1.2.4",
       "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.2.4.tgz",
       "integrity": "sha512-5uYhsJH8VJBTv7oslg4BznJYhDoRI6waYCxMmCdnTrcCrHA/fCFKoTFz2JKKE0HdDFUF7/oQuhzumXJK7paBRQ==",
-      "dev": true,
       "requires": {
         "es-errors": "^1.3.0",
         "function-bind": "^1.1.2",
@@ -1808,7 +1816,6 @@
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/gopd/-/gopd-1.0.1.tgz",
       "integrity": "sha512-d65bNlIadxvpb/A2abVdlqKqV563juRnZ1Wtk6s1sIR8uNsXR70xqIzVqxVf1eTqDunwT2MkczEeaezCKTZhwA==",
-      "dev": true,
       "requires": {
         "get-intrinsic": "^1.1.3"
       }
@@ -1890,7 +1897,6 @@
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/has-property-descriptors/-/has-property-descriptors-1.0.2.tgz",
       "integrity": "sha512-55JNKuIW+vq4Ke1BjOTjM2YctQIvCT7GFzHwmfZPGo5wnrgkid0YQtnAleFSqumZm4az3n2BS+erby5ipJdgrg==",
-      "dev": true,
       "requires": {
         "es-define-property": "^1.0.0"
       }
@@ -1898,14 +1904,12 @@
     "has-proto": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/has-proto/-/has-proto-1.0.3.tgz",
-      "integrity": "sha512-SJ1amZAJUiZS+PhsVLf5tGydlaVB8EdFpaSO4gmiUKUOxk8qzn5AIy4ZeJUmh22znIdk/uMAUT2pl3FxzVUH+Q==",
+      "integrity": "sha512-SJ1amZAJUiZS+PhsVLf5tGydlaVB8EdFpaSO4gmiUKUOxk8qzn5AIy4ZeJUmh22znIdk/uMAUT2pl3FxzVUH+Q=="
-      "dev": true
     },
     "has-symbols": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/has-symbols/-/has-symbols-1.0.3.tgz",
-      "integrity": "sha512-l3LCuF6MgDNwTDKkdYGEihYjt5pRPbEg46rtlmnSPlUbgmB8LOIrKJbYYFBSbnPaJexMKtiPO8hmeRjRz2Td+A==",
+      "integrity": "sha512-l3LCuF6MgDNwTDKkdYGEihYjt5pRPbEg46rtlmnSPlUbgmB8LOIrKJbYYFBSbnPaJexMKtiPO8hmeRjRz2Td+A=="
-      "dev": true
     },
     "has-tostringtag": {
       "version": "1.0.2",
@@ -1952,7 +1956,6 @@
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/hasown/-/hasown-2.0.2.tgz",
       "integrity": "sha512-0hJU9SCPvmMzIBdZFqNPXWa6dqh7WdH0cII9y+CyS8rG3nL48Bclra9HmKhVVUHyPWNH5Y7xDwAB7bfgSjkUMQ==",
-      "dev": true,
       "requires": {
         "function-bind": "^1.1.2"
       }
@@ -2405,6 +2408,24 @@
       "integrity": "sha512-xbbCH5dCYU5T8LcEhhuh7HJ88HXuW3qsI3Y0zOZFKfZEHcpWiHU/Jxzk629Brsab/mMiHQti9wMP+845RPe3Vg==",
       "dev": true
     },
+    "json-stable-stringify": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/json-stable-stringify/-/json-stable-stringify-1.1.1.tgz",
+      "integrity": "sha512-SU/971Kt5qVQfJpyDveVhQ/vya+5hvrjClFOcr8c0Fq5aODJjMwutrOfCU+eCnVD5gpx1Q3fEqkyom77zH1iIg==",
+      "requires": {
+        "call-bind": "^1.0.5",
+        "isarray": "^2.0.5",
+        "jsonify": "^0.0.1",
+        "object-keys": "^1.1.1"
+      },
+      "dependencies": {
+        "isarray": {
+          "version": "2.0.5",
+          "resolved": "https://registry.npmjs.org/isarray/-/isarray-2.0.5.tgz",
+          "integrity": "sha512-xHjhDr3cNBK0BzdUJSPXZntQUx/mwMS5Rw4A7lPJ90XGAO6ISP/ePDNuo0vhqOZU+UD5JoodwCAAoZQd3FeAKw=="
+        }
+      }
+    },
     "json-stable-stringify-without-jsonify": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/json-stable-stringify-without-jsonify/-/json-stable-stringify-without-jsonify-1.0.1.tgz",
@@ -2416,6 +2437,11 @@
       "resolved": "https://registry.npmjs.org/json5/-/json5-2.2.3.tgz",
       "integrity": "sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg=="
     },
+    "jsonify": {
+      "version": "0.0.1",
+      "resolved": "https://registry.npmjs.org/jsonify/-/jsonify-0.0.1.tgz",
+      "integrity": "sha512-2/Ki0GcmuqSrgFyelQq9M05y7PS0mEwuIzrf3f1fPqkVDVRvZrPZtVSMHxdgo8Aq0sxAOb/cr2aqqA3LeWHVPg=="
+    },
     "jsx-ast-utils": {
       "version": "2.4.1",
       "resolved": "https://registry.npmjs.org/jsx-ast-utils/-/jsx-ast-utils-2.4.1.tgz",
@@ -2781,8 +2807,7 @@
     "object-keys": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/object-keys/-/object-keys-1.1.1.tgz",
-      "integrity": "sha512-NuAESUOUMrlIXOfHKzD6bpPu3tYt3xvjNdRIQ+FeT0lNb4K8WR70CaDxhuNguS2XG+GjkyMwOzsN5ZktImfhLA==",
+      "integrity": "sha512-NuAESUOUMrlIXOfHKzD6bpPu3tYt3xvjNdRIQ+FeT0lNb4K8WR70CaDxhuNguS2XG+GjkyMwOzsN5ZktImfhLA=="
-      "dev": true
     },
     "object-visit": {
       "version": "1.0.1",
@@ -3419,7 +3444,6 @@
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/set-function-length/-/set-function-length-1.2.2.tgz",
       "integrity": "sha512-pgRc4hJ4/sNjWCSS9AmnS40x3bNMDTknHgL5UaMBTMyJnU90EgWh1Rz+MC9eFu4BuN/UwZjKQuY/1v3rM7HMfg==",
-      "dev": true,
       "requires": {
         "define-data-property": "^1.1.4",
         "es-errors": "^1.3.0",
@@ -3988,6 +4012,20 @@
         "lodash": "^4.17.4",
         "slice-ansi": "1.0.0",
         "string-width": "^2.1.1"
+      },
+      "dependencies": {
+        "ajv": {
+          "version": "6.12.6",
+          "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
+          "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
+          "dev": true,
+          "requires": {
+            "fast-deep-equal": "^3.1.1",
+            "fast-json-stable-stringify": "^2.0.0",
+            "json-schema-traverse": "^0.4.1",
+            "uri-js": "^4.2.2"
+          }
+        }
       }
     },
     "term-size": {

package.json

@@ -32,6 +32,7 @@
     "url": "https://github.com/billchurch/WebSSH2/issues"
   },
   "dependencies": {
+    "ajv": "^4.11.8",
     "debug": "~4.1.0",
     "read-config-ng": "~3.0.7",
     "socket.io": "~2.2.0",