我正在尝试通过网关连接到 EC2 实例。
如果我连接到网关
local> ssh gateway
然后我可以不用密码连接到 EC2
gateway> ssh ec2 # works
但是，尝试通过代理连接似乎需要身份文件。
Host gateway
HostName <gateway>
Host ec2
HostName ec2-<ec2>.compute.amazonaws.com
ProxyCommand ssh gateway -W %h:%p
local> ssh ec2
Permission denied (publickey).
我以为 ProxyCommand 基本上是将我登录到网关，然后登录到最终目的地。如果是这样，为什么它会要求我输入公钥，而网关设置为不需要公钥？我如何以与 ssh 进入网关然后 ssh 进入 ec2 相同的方式连接到 ec2 实例？
编辑：rsync 正常工作（不要求密钥文件）
rsync -pthrvz --rsync-path=/usr/bin/rsync --rsh='ssh gateway ssh' . ec2:/path
ssh -v 输出来自gateway> ssh ec2
gateway> ssh -v ec2
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to ec2 port 22.
debug1: Connection established.
debug1: identity file <snip> type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.2
debug1: match: OpenSSH_6.2 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.3
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'ec2' is known and matches the RSA host key.
debug1: Found key in ~/.ssh/known_hosts:63
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: ~/.ssh/identity
debug1: Offering public key: ~/.ssh/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug1: read PEM private key done: type RSA
debug1: Authentication succeeded (publickey).
debug1: channel 0: new [client-session]
debug1: Requesting [email protected]
debug1: Entering interactive session.
debug1: Sending environment.
尝试通过代理连接的 ssh -v 输出
local$ ssh -v ec2
OpenSSH_6.7p1 Ubuntu-5ubuntu1.3, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /home/matt/.ssh/config
debug1: /home/matt/.ssh/config line 9: Applying options for ec2
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Hostname has changed; re-reading configuration
debug1: Reading configuration data /home/matt/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Executing proxy command: exec ssh gateway -W ec2:22
debug1: permanently_drop_suid: 1000
debug1: identity file /home/matt/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.7p1 Ubuntu-5ubuntu1.3
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.2
debug1: match: OpenSSH_6.2 pat OpenSSH* compat 0x04000000
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr [email protected] none
debug1: kex: client->server aes128-ctr [email protected] none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA 73:<snip>:0c
debug1: Host 'ec2.compute.amazonaws.com' is known and matches the ECDSA host key.
debug1: Found key in /home/matt/.ssh/known_hosts:11
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/matt/.ssh/id_rsa
debug1: Authentications that can continue: publickey
debug1: Trying private key: /home/matt/.ssh/id_dsa
debug1: Trying private key: /home/matt/.ssh/id_ecdsa
debug1: Trying private key: /home/matt/.ssh/id_ed25519
debug1: No more authentication methods to try.
Permission denied (publickey).
问题似乎是它试图在我的计算机上找到密钥，而不是从网关机器上获取密钥。
答案1
ProxyCommand 的工作方式与您想象的不一样。指定的命令未在网关计算机上运行。而是在连接计算机上运行。
因此执行流程如下：
在“本地”机器上执行 ProxyCommand“ssh gateway -W %h:%p”。这将使用本地机器上的 RSA 身份建立到网关的 SSH 会话。-W 标志指定 stdin 和 stdout 将连接到网关上的 TCP 会话发起端，以连接到最终目的地。
建立代理会话后，本地设备上的 ssh 再次使用该会话向远程 SSH 服务器进行身份验证，同样使用本地凭据。
这有点令人困惑，但可以认为 ProxyCommand 只是在本地 SSH 客户端和作为最终目的地的 SSH 服务器之间设置了一个“管道”。然后，本地 SSH 客户端将使用该哑管道与最终目的地的 SSH 服务进行通信。
关键在于二在您的本地机器上运行的 SSH 实例，其中一个是 ProxyCommand，另一个是您想要建立的实际 SSH 连接！您应该能够通过查看本地机器上的“ps aux”输出来验证这一点。
这就可以解释为什么它尝试使用你本地盒子上的密钥材料而不是网关上的密钥材料进行身份验证。:-)
rsync 之所以有效，是因为你实际上是在执行“ssh gateway ssh”作为 --rsh 命令，它实际上在本地机器上运行一次 ssh 来连接到网关，然后在远程机器上再次运行一次 ssh，然后使用远程密钥材料。
希望这可以帮助。