您的要求不明确.
我建议您阅读有关 SSH [ rfc [ ^ ]的链接详细信息)，并获取源代码腻子 [ ^ ]是金矿:)

OpenSSH也是一个不错的选择

Your requirement is not clear.
I would suggest you read about SSH[^](secure shell host) protocol(also see the rfc[^] link for the protocol detail) And for Source code Putty[^] is the gold mine :)

OpenSSH is also a good option