如何在C / C ++跨平台上以编程方式创建ssh隧道？

Question

I need to connect via TCP to a port that's behind a firewall, accessible through an SSH tunnel. I can achieve connection by opening a tunnel and hittting that port, but I want to build this tunneling in to my application.

Additionally, I want to be able to provide automatic login by use of having authorized keys on the server

This must work on the following platforms (in order of importance)

• iOS (trickiest because I can't fork an ssh tunnel like I can on other platforms)
• OS X
• Linux
• Windows

What's the easy way to do this? I don't want to spend a great deal of effort obviously since this isn't the meat of my application. But I'll reuse it so I may care enough to "do things right"

Answer 1

But libssh2 is BSD-licensed and appears to have the functionality needed

Looks like: libssh2_channel_direct_tcpip_ex will be the call

Note that the LGPL'd libssh is a problem because on iOS apps you MUST statically link and CANNOT dynamically link to libraries. Therefore, using an LGPL'd library means my source becomes open source.

Answer 2

Libssh is a very good client implementation for SSH protocol. I have written a blog on this. There is also a sample application demonstrating the same. We use the same technique in MONyog (MySQL monitor).

Answer 3

如果你想查看商业LIB，www.chilkatsoft.com/，它是适用于所有语言的genric C ++库，其中支持IOS的SSH隧道。

Answer 4

Does the LGPL differentiate between linking dynamically and statically? I don't think so.

The library code (ie embedding your own SSH implementation) looks most versatile to me. Except the fact that you might inherit security problems.

On MacOSX/Linux/Unix, you can simply invoke 'ssh' and assume it exists (or make it as a precondition). On Windows, you would rely on putty and friends. I don't think that's a good idea.