我正在使用autossh -M 20000 -fN -R 19999:localhost:22 -i mycert.pem ubuntu@myaws.hopto.org建立到我的AWS机器的反向隧道。现在，当我尝试从aws访问计算机时，得到以下信息：
$ ssh ron@localhost -P 19999
Permission denied (publickey).
为什么会这样？详细选项显示：
$ ssh ron@localhost -v -P 19999
OpenSSH_7.2p2 Ubuntu-4ubuntu2.4, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /home/ubuntu/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ubuntu/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ubuntu/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ubuntu/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ubuntu/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ubuntu/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ubuntu/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ubuntu/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to localhost:22 as 'ron'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:kT8pM3YwDEYqE+CFzyWQDiSVCLhgMjPLWBJXYPl1BZs
debug1: Host 'localhost' is known and matches the ECDSA host key.
debug1: Found key in /home/ubuntu/.ssh/known_hosts:5
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/ubuntu/.ssh/id_rsa
debug1: Trying private key: /home/ubuntu/.ssh/id_dsa
debug1: Trying private key: /home/ubuntu/.ssh/id_ecdsa
debug1: Trying private key: /home/ubuntu/.ssh/id_ed25519
debug1: No more authentication methods to try.
Permission denied (publickey).
这是怎么回事？为什么不让我连接？
EDIT1
我发现当我使用autossh -M 20000 -R 19999:localhost:22 -i mycert.pem时，我实际上可以建立一个连接，但是目标计算机仍会保持登录状态，这不是我想要的！为什么-fN导致此功能不起作用？
答案 0 :(得分：1)
我也一直为此苦苦挣扎。我的答案可能很简单，是一个典型的初学者错误，可能不是您的答案，但是我会在这里发布此消息，以防其他人遇到麻烦并对他们有帮助。
您试图将ssh从转换为的计算机的公共密钥必须存在于本地计算机的authorized_keys文件中。
反向SSH连接到本地端口，实际上这是您自己的本地计算机，因此它将在您的本地计算机上查找不存在的public_authors_keys文件中的公共密钥。很容易对此感到困惑，因为您使用的是“ localhost”作为地址，但可以想象一下，您是在某个随机端口上将门户网站打开到远程位置，然后以该远程用户的身份从该位置进行连接到您的港口。当它连接到端口时，仍然需要通过端口请求许可才能向下发送命令。由于它是您家的门户，因此它将在那寻找钥匙。如果端口的另一端没有钥匙，它将无法正常工作。
ELI5风格：
您希望另一个世界向您发送东西，但他们不能这样做，因为您处于秘密位置，因此您将红色端口和蓝色端口连接到另一个世界。
您跳过红色端口，但另一端的人不知道蓝色端口在哪里，因此您必须告诉他们蓝色端口在哪里。他们试图通过港口，但无法进入，因为您尚未授权他们过来，并且今天的安全性也不足。
因此，您让他们在那里制作钥匙卡，然后将其带回自己的世界，并告诉自己的安全性“此钥匙卡不错，请让他们进入。”
现在，您可以再次返回，并告诉他们敲门。这次安全部门发现这些人是朋友，他们被允许进来。
所以：
localuser@localmachine:~$ ssh -r <remote port>:localhost:localport remoteuser@remoteaddress
remoteuser@remoteaddress:~$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/$USER/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/$USER/.ssh/id_rsa.
Your public key has been saved in /home/$USER/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:sadfhjkljashdlkfjahw039ufrg094ut remoteuser@remotemachine
The key's randomart image is:
+---[RSA 2048]----+
|=+ +. ..+ o . |
|o ofake art. . |
|asdfghjk |
|+ . .o. . + . |
|.+R . fx s ++ o |
|B + .. . . |
|=+ +.. . . |
|..o .. 0. 0. |
| + o ++ ==o|
+----[SHA256]-----+
remoteuser@remoteaddress:~$ clip ./ssh/id_rsa.pub (or copy it however you can)
remoteuser@remoteaddress:~$ exit
localuser@localmachine:~$ nano/vi/whatever .ssh/authorized_keys (paste the public key there)
localuser@localmachine:~$ ssh -r <remote port>:localhost:localport remoteuser@remoteaddress
remoteuser@remoteaddress:~$ ssh localhost -p <remote port>
同样，这主要是针对那些具有反向ssh的新功能并且遇到“公钥”错误的人。希望我能帮上忙！