ssh: Add Linux ssh-agent support

sedwards2009 · Jun 9, 2024 · f8da11c · f8da11c
1 parent bb19059
commit f8da11c
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Showing 3 changed files with 42 additions and 5 deletions.
diff --git a/extensions/SSHSessionBackend/src/SSHPty.ts b/extensions/SSHSessionBackend/src/SSHPty.ts
@@ -26,6 +26,7 @@ export interface PtyOptions {
   username: string;
   privateKeyFilenames?: string[];
   tryPasswordAuth: boolean;
+  agentSocketPath?: string;
 }
 
 enum PtyState {
@@ -48,6 +49,7 @@ export class SSHPty implements Pty {
   #password: string = "";
 
   #ptyOptions: PtyOptions = null;
+  #tryAgentAuth = false;
   #verifyCallback: ssh2.VerifyCallback = null;
 
   #permittedDataSize = 0;
@@ -154,11 +156,14 @@ export class SSHPty implements Pty {
       });
     });
 
+    this.#tryAgentAuth = options.agentSocketPath !== undefined;
+
     this.#sshConnection.connect({
       host: options.host,
       port: options.port,
       username: options.username,
       tryKeyboard: true,
+      agent: options.agentSocketPath,
       authHandler: (
           methodsLeft: ssh2.AuthenticationType[],
           partialSuccess: boolean,
@@ -359,6 +364,12 @@ export class SSHPty implements Pty {
       partialSuccess: boolean,
       callback: ssh2.NextAuthHandler): void {
 
+    if (this.#tryAgentAuth) {
+      this.#tryAgentAuth = false;
+      callback({type: "agent", agent: this.#ptyOptions.agentSocketPath, username: this.#ptyOptions.username});
+      return;
+    }
+
     while (this.#remainingPrivateKeyFilenames.length !== 0) {
       const keyFilename = this.#remainingPrivateKeyFilenames.pop();
       if (this.#handlePrivateKeyAuth(keyFilename, callback)) {
@@ -368,6 +379,7 @@ export class SSHPty implements Pty {
 
     if (this.#tryPasswordAuth) {
       this.#startPasswordInput(callback);
+      return;
     }
 
     callback(<any>false);

diff --git a/extensions/SSHSessionBackend/src/SSHSessionBackendExtension.ts b/extensions/SSHSessionBackend/src/SSHSessionBackendExtension.ts
@@ -16,7 +16,8 @@ import { PtyOptions, SSHPty } from "./SSHPty";
 enum AuthenticationMethod {
   DEFAULT_KEYS_PASSWORD,
   PASSWORD_ONLY,
-  KEY_FILE_ONLY
+  KEY_FILE_ONLY,
+  SSH_AGENT_ONLY,
 };
 
 // Note: This is duplicated in SSHSessionEditorExtension.ts.
@@ -63,12 +64,15 @@ class SSHBackend implements SessionBackend {
         tryPasswordAuth = true;
         break;
 
+      case AuthenticationMethod.KEY_FILE_ONLY:
+        privateKeyFilenames.push(sessionConfig.keyFilePath);
+        break;
+
       case AuthenticationMethod.PASSWORD_ONLY:
         tryPasswordAuth = true;
         break;
 
-      case AuthenticationMethod.KEY_FILE_ONLY:
-        privateKeyFilenames.push(sessionConfig.keyFilePath);
+      default:
         break;
     }
 
@@ -82,11 +86,26 @@ class SSHBackend implements SessionBackend {
       username: username,
       privateKeyFilenames,
       tryPasswordAuth,
+      agentSocketPath: this.#createAgentSocketPath(sessionConfig),
     };
 
     return new SSHPty(this._log, options);
   }
 
+  #createAgentSocketPath(sessionConfig: SSHSessionConfiguration): string {
+    const needAgent = sessionConfig.authenicationMethod === AuthenticationMethod.DEFAULT_KEYS_PASSWORD ||
+                      sessionConfig.authenicationMethod === AuthenticationMethod.SSH_AGENT_ONLY;
+    if (! needAgent) {
+      return undefined;
+    }
+
+    if (process.platform === "win32") {
+      return undefined;
+    } else {
+      return process.env.SSH_AUTH_SOCK;
+    }
+  }
+
   #createEnv(sessionOptions: CreateSessionOptions): EnvironmentMap {
     const ptyEnv: EnvironmentMap = {};
     const processEnv = process.env;

diff --git a/extensions/SSHSessionEditor/src/SSHSessionEditorExtension.ts b/extensions/SSHSessionEditor/src/SSHSessionEditorExtension.ts
@@ -14,10 +14,16 @@ let log: Logger = null;
 enum AuthenticationMethod {
   DEFAULT_KEYS_PASSWORD,
   PASSWORD_ONLY,
-  KEY_FILE_ONLY
+  KEY_FILE_ONLY,
+  SSH_AGENT_ONLY,
 };
 
-const AUTHENTICATION_METHOD_LABELS = ["Default OpenSSH keys, Password", "Password only", "Key file only"];
+const AUTHENTICATION_METHOD_LABELS = [
+  "SSH Agent, Default OpenSSH keys, Password",
+  "Password only",
+  "Key file only",
+  "SSH Agent only"
+];
 
 // Note: This is duplicated in SSHSessionBackendExtension.ts.
 interface SSHSessionConfiguration extends SessionConfiguration {