fix: properly handle SSH PTY dimensions on initial connection (#350)

  - Store terminal dimensions (cols/rows) in sessionState during authentication
  - Separate PTY options from environment options in SSH shell() method
  - Fix SSH2 library parameter interpretation issue that prevented initial dimensions from being applied

  This ensures the SSH2 library correctly sets PTY dimensions when creating the shell,
  resolving the issue where terminals would show 24x80 instead of actual dimensions.

Author: billchurch

app/socket.js

@@ -106,11 +106,23 @@ class WebSSH2Socket extends EventEmitter {
 
   handleAuthenticate(creds) {
     debug(`handleAuthenticate: ${this.socket.id}, %O`, maskSensitiveData(creds))
+    debug(`handleAuthenticate: received cols=${creds.cols}, rows=${creds.rows}`)
 
     if (isValidCredentials(creds)) {
       // Set term if provided, otherwise use config default
       this.sessionState.term = validateSshTerm(creds.term) ? creds.term : this.config.ssh.term
 
+      // Store terminal dimensions if provided with credentials
+      if (creds.cols && validator.isInt(creds.cols.toString())) {
+        this.sessionState.cols = parseInt(creds.cols, 10)
+        debug(`handleAuthenticate: storing cols: ${this.sessionState.cols}`)
+      }
+      if (creds.rows && validator.isInt(creds.rows.toString())) {
+        this.sessionState.rows = parseInt(creds.rows, 10)
+        debug(`handleAuthenticate: storing rows: ${this.sessionState.rows}`)
+      }
+      debug(`handleAuthenticate: sessionState now has cols=${this.sessionState.cols}, rows=${this.sessionState.rows}`)
+
       this.initializeConnection(creds)
     } else {
       debug(`handleAuthenticate: ${this.socket.id}, CREDENTIALS INVALID`)
@@ -212,15 +224,16 @@ class WebSSH2Socket extends EventEmitter {
     // Get envVars from socket session if they exist
     const envVars = this.socket.request.session.envVars || null
 
+    const shellOptions = {
+      term: this.sessionState.term || 'xterm-color',
+      cols: this.sessionState.cols || 80,
+      rows: this.sessionState.rows || 24,
+    }
+    
+    debug(`createShell: Creating shell with options:`, shellOptions)
+
     this.ssh
-      .shell(
-        {
-          term: this.sessionState.term,
-          cols: this.sessionState.cols,
-          rows: this.sessionState.rows,
-        },
-        envVars
-      )
+      .shell(shellOptions, envVars)
       .then((stream) => {
         stream.on('data', (data) => {
           this.socket.emit('data', data.toString('utf-8'))

app/ssh.js

@@ -276,12 +276,26 @@ class SSHConnection extends EventEmitter {
    * @returns {Promise<Object>} - A promise that resolves with the SSH shell stream
    */
   shell(options, envVars) {
-    const shellOptions = Object.assign({}, options, {
-      env: this.getEnvironment(envVars),
-    })
+    // Separate PTY options from environment options
+    // SSH2 expects them as separate parameters
+    const ptyOptions = {
+      term: options.term,
+      rows: options.rows,
+      cols: options.cols,
+      width: options.width,
+      height: options.height,
+    }
+    
+    // Only include environment options if we have envVars
+    const envOptions = envVars ? {
+      env: this.getEnvironment(envVars)
+    } : undefined
+    
+    debug(`shell: Creating shell with PTY options:`, ptyOptions, 'and env options:', envOptions)
 
     return new Promise((resolve, reject) => {
-      this.conn.shell(shellOptions, (err, stream) => {
+      // Pass PTY options as first param, env options as second
+      this.conn.shell(ptyOptions, envOptions, (err, stream) => {
         if (err) {
           reject(err)
         } else {

package-lock.json

@@ -40,7 +40,7 @@
     "jsmasker": "^1.4.0",
     "read-config-ng": "~3.0.7",
     "socket.io": "^4.8.1",
-    "ssh2": "1.16",
+    "ssh2": "1.17",
     "validator": "^13.15.15",
     "webssh2_client": "^0.2.29"
   },