feature: Add support for auth-agent (server) with adjusted test

README.md

@@ -1217,6 +1217,9 @@ You can find more examples in the `examples` directory of this repository.
 
 * **forwardOut**(< _string_ >boundAddr, < _integer_ >boundPort, < _string_ >remoteAddr, < _integer_ >remotePort, < _function_ >callback) - _(void)_ - Alert the client of an incoming TCP connection on `boundAddr` on port `boundPort` from `remoteAddr` on port `remotePort`. `callback` has 2 parameters: < _Error_ >err, < _Channel_ >stream.
 
+* **openssh_authAgent**(< _function_ >callback) - _boolean_ - Alert the client of an incoming `ssh-agent` socket connection. `callback` has 2 parameters: < _Error_ >err, < _Channel_ >stream. Returns `false` if you should wait for the `continue` event before sending any more traffic.
+
+
 * **openssh_forwardOutStreamLocal**(< _string_ >socketPath, < _function_ >callback) - _(void)_ - Alert the client of an incoming UNIX domain socket connection on `socketPath`. `callback` has 2 parameters: < _Error_ >err, < _Channel_ >stream.
 
 * **rekey**([< _function_ >callback]) - _(void)_ - Initiates a rekey with the client. If `callback` is supplied, it is added as a one-time handler for the `rekey` event.

lib/server.js

@@ -1298,6 +1298,12 @@ class Client extends EventEmitter {
     return this;
   }
 
+
+  openssh_authAgent(cb) {
+    openChannel(this, 'auth-agent@openssh.com', cb);
+    return this;
+  }
+
   openssh_forwardOutStreamLocal(socketPath, cb) {
     const opts = { socketPath };
     openChannel(this, 'forwarded-streamlocal@openssh.com', opts, cb);
@@ -1362,6 +1368,9 @@ function openChannel(self, type, opts, cb) {
     case 'x11':
       self._protocol.x11(localChan, initWindow, maxPacket, opts);
       break;
+    case 'auth-agent@openssh.com':
+      self._protocol.openssh_authAgent(localChan, initWindow, maxPacket);
+      break;
     case 'forwarded-streamlocal@openssh.com':
       self._protocol.openssh_forwardedStreamLocal(
         localChan, initWindow, maxPacket, opts

test/test-openssh.js

@@ -1,6 +1,8 @@
 'use strict';
 
 const assert = require('assert');
+const fs = require('fs');
+const net = require('net');
 const { inspect } = require('util');
 
 const {
@@ -259,3 +261,76 @@ const serverCfg = { hostKeys: [ fixture('ssh_host_rsa_key') ] };
     accept();
   }));
 }
+
+{
+  const { join } = require('path');
+  const { tmpdir } = require('os');
+
+  const agentSockPath = process.platform === 'win32'
+    ? `\\\\.\\pipe\\ssh2-test-agent-${process.pid}`
+    : join(tmpdir(), `ssh2-test-agent-${process.pid}.sock`);
+
+  const isWin = process.platform === 'win32';
+
+  if (!isWin && fs.existsSync(agentSockPath))
+    fs.unlinkSync(agentSockPath);
+
+  // Fake agent: echoes back whatever it receives
+  const agentServer = net.createServer(mustCall((sock) => {
+    sock.on('data', mustCallAtLeast((data) => {
+      sock.write(data);
+    }));
+  }));
+
+  agentServer.listen(agentSockPath);
+
+  const { client, server } = setup_(
+    'Server-initiated openssh_authAgent channel',
+    {
+      client: {
+        ...clientCfg,
+        agent: agentSockPath,
+      },
+      server: serverCfg,
+      debug,
+    },
+  );
+
+  server.on('connection', mustCall((conn) => {
+    conn.on('authentication', mustCall((ctx) => {
+      ctx.accept();
+    })).on('ready', mustCall(() => {
+      conn.on('session', mustCall((accept, reject) => {
+        accept().on('auth-agent', mustCall((accept, reject) => {
+          accept && accept();
+        })).on('exec', mustCall((accept, reject, info) => {
+          const stream = accept();
+          stream.exit(0);
+          stream.end();
+
+          conn.openssh_authAgent(mustCall((err, agentStream) => {
+            assert(!err, `Unexpected openssh_authAgent error: ${err}`);
+
+            const testData = 'agent-ping';
+            agentStream.on('data', mustCallAtLeast((data) => {
+              assert(data.toString() === testData,
+                `Expected '${testData}', got: '${data}'`);
+              conn.end();
+              agentServer.close();
+              if (!isWin && fs.existsSync(agentSockPath))
+                fs.unlinkSync(agentSockPath);
+            }));
+            agentStream.write(testData);
+          }));
+        }));
+      }));
+    }));
+  }));
+
+  client.on('ready', mustCall(() => {
+    client.exec('foo', { agentForward: true }, mustCall((err, stream) => {
+      assert(!err, `Unexpected exec error: ${err}`);
+      stream.resume();
+    }));
+  }));
+}