将 ssh (security shell) 移植到 vxworks

openssh 依赖 openssl，这两个东西主要针对posix系统，移植到 vxworks 等实时系统有相当的难度。

可以考虑移植如下的库(ssh server)：

dropbear：

https://matt.ucc.asn.au/dropbear/dropbear.html

https://github.com/mkj/dropbear

https://github.com/mkj/dropbear/blob/master/config.sub

iconfidant:   (似乎是商业版)

http://www.iconlabs.com/prod/products/secure-remote-access/iconfidant

nanossh:    (似乎也要钱)

https://www.mocana.com/iot-security/nanossh

http://archive.eetasia.com/www.eetasia.com/ART_8800623277_499495_NP_e41f0a39.HTM                     (freescale 的cpu架构下的nanossh是要钱的)

http://linuxmafia.com/ssh/vxworks.html

ssh client:

http://lists.mindrot.org/pipermail/openssh-unix-dev/2008-May/026439.html

ssh源代码中的 KEX 是什么意思：

The listed KEXs are the algorithms allowed by the server for key exchange.

下面是一些ssh的开源库：

https://github.com/substack/libssh           mulitplatform C library implementing the SSHv2 and SSHv1 protocol on client and server side

https://github.com/diogo-fernan/carapaca         A Java implementation of a simpler version of SSH.

https://github.com/gpg/gsti                       This is a "C" library which implements a basic part of the protocol used by SSH to create a secure transport channel。

https://github.com/hierynomus/sshj          ssh, scp and sftp for java

https://github.com/ePaul/jsch-documentation      A variant of JSch with javadoc for the public methods。 （The gritty terminal was written to use Jsch, but with better handling and vt102 emulation）

https://github.com/openssh/openssh-portable

https://github.com/paramiko/paramiko             The leading native Python SSHv2 protocol library.

https://github.com/ronf/asyncssh            a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python asyncio framework.

https://mina.apache.org/sshd-project/embedding_ssh.html        Embedding SSHD in 5 minutes, java mina

openssl 对不同架构的configure方式：

./configure no-asm no-threads --openssldir=d:\\openssl-0.9.7b vxworks-ppc405