我正在尝试使用以下命令连接到SFTP服务器：
<?php
ssh2_connect("my-host.com", 443, array("client_to_server" => array("mac" => "hmac-sha2-256,hmac-sha2-512,umac-64@openssh.com")));
但是我收到以下错误消息：
PHP Warning: ssh2_connect(): Error starting up SSH connection(-5): Unable to exchange encryption keys in Command line code on line 1
PHP Stack trace:
PHP 1. {main}() Command line code:0
PHP 2. ssh2_connect() Command line code:1
PHP Warning: ssh2_connect(): Unable to connect to my-host.com in Command line code on line 1
PHP Stack trace:
PHP 1. {main}() Command line code:0
PHP 2. ssh2_connect() Command line code:1
当我检查我的SFTP服务器的日志时，我可以看到：
2016-08-17 15:32:43,104 mod_sftp/0.9.9[10701]: no shared client-to-server MAC algorithm found (client sent 'hmcom', server sent 'hmac-sha2-256,hmac-sha2-512,umac-64@openssh.com')