Add support for ssh algorithms, compaitibale with old embeded devices

Author: FANG.Ge

README.md

@@ -122,7 +122,7 @@ Debugging using ssh automatically converts all paths between client & server and
 redirects X11 output from the server to the client.  
 Simply add a `ssh` object in your `launch` request.
 
-```
+```jsonc
 "request": "launch",
 "target": "./executable",
 "cwd": "${workspaceRoot}",
@@ -137,7 +137,11 @@ Simply add a `ssh` object in your `launch` request.
 	// x11port may also be specified as string containing only numbers (useful to use configuration variables)
 	"x11port": 6000,
 	// Optional, content will be executed on the SSH host before the debugger call.
-	"bootstrap": "source /home/remoteUser/some-env"
+	"bootstrap": "source /home/remoteUser/some-env",
+	// Optional, override the default transport layer algorithms used for the connection
+	"algorithms": {
+		"kex" : [ "diffie-hellman-group-exchange-sha1" ]
+  }
 }
 ```
 
@@ -151,6 +155,9 @@ For X11 forwarding to work you first need to enable it in your Display Manager a
 connections. To allow connections you can either add an entry for applications or run `xhost +`
 in the console while you are debugging and turn it off again when you are done using `xhost -`.
 
+
+SSH algorithms used by some old embedded devices may be out of date, there is a compatible method using `algorithms`. `kex`, `cipher`,`compress`, `hmac`, `serverHostKey` are known to be supported in algorithms. The data format of these keys is array. Supported values can be found in [`msc/ssh`](https://github.com/mscdex/ssh2/blob/master/README.md#client-methods) (Client methods->connect->algorithms).
+
 Because some builds requires one or more environment files to be sourced before running any
 command, you can use the `ssh.bootstrap` option to add some extra commands which will be prepended
 to the debugger call (using `&&` to join both).

package.json

@@ -288,6 +288,32 @@
 									"bootstrap": {
 										"type": "string",
 										"description": "Content will be executed on the SSH host before the debugger call."
+									},
+									"algorithms": {
+										"type": "object",
+										"description": "This option allows you to explicitly override the default transport layer algorithms used for the connection.",
+										"properties": {
+											"cipher": {
+												"type": "array",
+												"description": "Ciphers."
+											},
+											"compress": {
+												"type": "array",
+												"description": "Compression algorithms."
+											},
+											"hmac": {
+												"type": "array",
+												"description": "(H)MAC algorithms."
+											},
+											"kex": {
+												"type": "array",
+												"description": "Key exchange algorithms."
+											},
+											"serverHostKey": {
+												"type": "array",
+												"description": "Server host key formats."
+											}
+										}
 									}
 								}
 							}

src/backend/backend.ts

@@ -47,6 +47,7 @@ export interface SSHArguments {
 	x11host: string;
 	bootstrap: string;
 	sourceFileMap: { [index: string]: string };
+	algorithms: any;
 }
 
 export interface IBackend {

src/backend/mi2/mi2.ts

@@ -135,6 +135,10 @@ export class MI2 extends EventEmitter implements IBackend {
 				connectionArgs.password = args.password;
 			}
 
+			if (args.algorithms) {
+				connectionArgs.algorithms = args.algorithms;
+			}
+
 			this.sshConn.on("ready", () => {
 				this.log("stdout", "Running " + this.application + " over ssh...");
 				const execArgs: any = {};