我有 2 台相同的服务器，运行 CentOS Linux 版本 7.4.1708（核心）x64。两者都使用相同的软件包安装。
在两台服务器中，我都安装了私钥（我在笔记本电脑上使用的私钥），但在服务器中我没有任何 id_rsa 密钥。
我习惯登录到服务器，然后从该服务器 sshing 到另一个服务器来提取文件或一些随机的东西。我一直都能做到，并且 SSH 使用密钥转发没有任何问题。
现在在这台服务器之间它不起作用，我收到：“sign_and_send_pubkey：签名失败：代理拒绝操作”消息。但真正奇怪的是它只在这两台服务器之间。如果我通过 SSH 连接到其中一台服务器，然后通过 SSH 连接到另一台服务器，则它可以正常工作。我不知道这是否与 OpenSSH 版本有关（sshd 版本 OpenSSH_7.4，OpenSSL 1.0.2k-fips 26 Jan 2017），这是我发现的唯一区别。
我已经尝试过描述 ssh-add 等的方法，但都不起作用。ssh-add -l确实显示了我的钥匙。正如我已经提到的，如果我 ssh 到另一台服务器，它就可以工作。我不知道是什么导致了这个问题。以下是来自客户端和服务器的登录尝试日志：
客户端尝试：
OpenSSH_7.4p1, OpenSSL 1.0.2k-fips 26 Jan 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 58: Applying options for *
debug1: Connecting to 192.168.0.22 [192.168.0.22] port 7922.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 192.168.0.22:7922 as 'root'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: curve25519-sha256 need=64 dh_need=64
debug1: kex: curve25519-sha256 need=64 dh_need=64
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:oWEB74igSY8hrsToszYlI71rlQHFUkxqZp3V9ZLDyeU
debug1: Host '[192.168.0.22]:7922' is known and matches the ECDSA host key.
debug1: Found key in /root/.ssh/known_hosts:1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey after 134217728 blocks
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,gssapi-keyex,gssapi-with-mic
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available (default cache: KEYRING:persistent:0)
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available (default cache: KEYRING:persistent:0)
debug1: Next authentication method: publickey
debug1: Offering DSA public key: [1024-bit dsa, JGGV@the-best, Mon Oct 07 2002 21:53:53]
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
debug1: Offering RSA public key: Laundry Dispens-inators root key
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
debug1: Offering RSA public key: pvera@VCLP06
debug1: Server accepts key: pkalg rsa-sha2-512 blen 279
sign_and_send_pubkey: signing failed: agent refused operation
debug1: Offering RSA public key: jggv@JGGV
debug1: Server accepts key: pkalg rsa-sha2-512 blen 277
sign_and_send_pubkey: signing failed: agent refused operation
debug1: Offering RSA public key: pvera@VCLP06
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
debug1: Trying private key: /root/.ssh/id_rsa
debug1: Trying private key: /root/.ssh/id_dsa
debug1: Trying private key: /root/.ssh/id_ecdsa
debug1: Trying private key: /root/.ssh/id_ed25519
debug1: No more authentication methods to try.
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
服务器日志：
Connection from 192.168.0.27 port 33958 on 192.168.0.22 port 7922
debug1: Client protocol version 2.0; client software version OpenSSH_7.4
debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000
debug1: Local version string SSH-2.0-OpenSSH_7.4
debug1: Enabling compatibility mode for protocol 2.0
debug1: SELinux support disabled [preauth]
debug1: permanently_set_uid: 74/74 [preauth]
debug1: list_hostkey_types: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519 [preauth]
debug1: SSH2_MSG_KEXINIT sent [preauth]
debug1: SSH2_MSG_KEXINIT received [preauth]
debug1: kex: algorithm: curve25519-sha256 [preauth]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256 [preauth]
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none [preauth]
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none [preauth]
debug1: kex: curve25519-sha256 need=64 dh_need=64 [preauth]
debug1: kex: curve25519-sha256 need=64 dh_need=64 [preauth]
debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth]
debug1: rekey after 134217728 blocks [preauth]
debug1: SSH2_MSG_NEWKEYS sent [preauth]
debug1: expecting SSH2_MSG_NEWKEYS [preauth]
debug1: SSH2_MSG_NEWKEYS received [preauth]
debug1: rekey after 134217728 blocks [preauth]
debug1: KEX done [preauth]
debug1: userauth-request for user root service ssh-connection method none [preauth]
debug1: attempt 0 failures 0 [preauth]
debug1: PAM: initializing for "root"
debug1: PAM: setting PAM_RHOST to "192.168.0.27"
debug1: PAM: setting PAM_TTY to "ssh"
debug1: userauth-request for user root service ssh-connection method publickey [preauth]
debug1: attempt 1 failures 0 [preauth]
debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for DSA SHA256:Klpud/mybsWXCWRyLvrNeEe05arBwTwU6uz5kcAkEEA [preauth]
debug1: temporarily_use_uid: 0/0 (e=0/0)
debug1: trying public key file /root/.ssh/authorized_keys
debug1: fd 4 clearing O_NONBLOCK
debug1: restore_uid: 0/0
Failed publickey for root from 192.168.0.27 port 33958 ssh2: DSA SHA256:Klpud/mybsWXCWRyLvrNeEe05arBwTwU6uz5kcAkEEA
debug1: userauth-request for user root service ssh-connection method publickey [preauth]
debug1: attempt 2 failures 1 [preauth]
debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for RSA SHA256:rpYwsIO0JjUvi4GOM3X7GinFIZ/AKNvdujvmesW+xOA [preauth]
debug1: temporarily_use_uid: 0/0 (e=0/0)
debug1: trying public key file /root/.ssh/authorized_keys
debug1: fd 4 clearing O_NONBLOCK
debug1: restore_uid: 0/0
Failed publickey for root from 192.168.0.27 port 33958 ssh2: RSA SHA256:rpYwsIO0JjUvi4GOM3X7GinFIZ/AKNvdujvmesW+xOA
debug1: userauth-request for user root service ssh-connection method publickey [preauth]
debug1: attempt 3 failures 2 [preauth]
debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for RSA SHA256:mpZgL1m3o8uJEVxBHWJwb2txIJPgPGpQWz2zvYkoaSk [preauth]
debug1: temporarily_use_uid: 0/0 (e=0/0)
debug1: trying public key file /root/.ssh/authorized_keys
debug1: fd 4 clearing O_NONBLOCK
debug1: matching key found: file /root/.ssh/authorized_keys, line 2 RSA SHA256:mpZgL1m3o8uJEVxBHWJwb2txIJPgPGpQWz2zvYkoaSk
debug1: restore_uid: 0/0
Postponed publickey for root from 192.168.0.27 port 33958 ssh2 [preauth]
debug1: userauth-request for user root service ssh-connection method publickey [preauth]
debug1: attempt 4 failures 2 [preauth]
debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for RSA SHA256:nhJgL2r5V1K6Z6DRw6jjKL6O4Pqv3/vYRtq35oqERwc [preauth]
debug1: temporarily_use_uid: 0/0 (e=0/0)
debug1: trying public key file /root/.ssh/authorized_keys
debug1: fd 4 clearing O_NONBLOCK
debug1: matching key found: file /root/.ssh/authorized_keys, line 1 RSA SHA256:nhJgL2r5V1K6Z6DRw6jjKL6O4Pqv3/vYRtq35oqERwc
debug1: restore_uid: 0/0
Postponed publickey for root from 192.168.0.27 port 33958 ssh2 [preauth]
debug1: userauth-request for user root service ssh-connection method publickey [preauth]
debug1: attempt 5 failures 2 [preauth]
debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for RSA SHA256:cmo8wJpMpQbjZHEtMDjroxvyzjbe/rQtRNfaJ15hi1A [preauth]
debug1: temporarily_use_uid: 0/0 (e=0/0)
debug1: trying public key file /root/.ssh/authorized_keys
debug1: fd 4 clearing O_NONBLOCK
debug1: restore_uid: 0/0
Failed publickey for root from 192.168.0.27 port 33958 ssh2: RSA SHA256:cmo8wJpMpQbjZHEtMDjroxvyzjbe/rQtRNfaJ15hi1A
Connection closed by 192.168.0.27 port 33958 [preauth]
debug1: do_cleanup [preauth]
debug1: monitor_read_log: child log fd closed
debug1: do_cleanup
debug1: PAM: cleanup
debug1: Killing privsep child 5251
我真的不知道还能做什么，我已经花了一天多的时间了。