我有几台 CentOS 9 和一台 CentOS 7 虚拟机。所有这些都配置为信任我的 SSH CA 进行密钥验证。我可以使用密钥 A ssh 到所有这些密钥，但 CentOS 7 VM 拒绝密钥 B。我似乎无法弄清楚出了什么问题，两者都是由同一个 CA 签名的，登录原理相同。详细信息键 A 是：
.ssh/id_rsa-cert.pub:
Type: [email protected] user certificate
Public key: RSA-CERT SHA256:u75yZ/08ZApB3/Vyq0Y48gACwNHL/WrLKtDQP51ftMg
Signing CA: RSA SHA256:L4QSnMqV0ohHA7qMlS58VBcKVlmL1FB/vaIAs7vC6zw (using rsa-sha2-512)
Key ID: "matt"
Serial: 1
Valid: forever
Principals:
matt
Critical Options: (none)
Extensions:
permit-X11-forwarding
permit-agent-forwarding
permit-port-forwarding
permit-pty
permit-user-rc
按键B：
.ssh/id_rsa-cert.pub:
Type: [email protected] user certificate
Public key: RSA-CERT SHA256:RAxiw1VaHXlE3rjagbQDt1dMs7dJWxECftlJbEW0zqg
Signing CA: RSA SHA256:L4QSnMqV0ohHA7qMlS58VBcKVlmL1FB/vaIAs7vC6zw (using rsa-sha2-512)
Key ID: "ans-usr"
Serial: 2
Valid: forever
Principals:
matt
Critical Options: (none)
Extensions:
permit-X11-forwarding
permit-agent-forwarding
permit-port-forwarding
permit-pty
permit-user-rc
CentOS 7服务器上的sshd_config文件是：
PubkeyAuthentication yes
TrustedUserCAKeys /etc/ssh/ca.pub
PasswordAuthentication no
PermitEmptyPasswords no
KbdInteractiveAuthentication yes
CentOS 7 服务器上的 sshd 拒绝登录尝试时的调试输出如下：
debug2: load_server_config: filename /etc/ssh/sshd_config
debug2: load_server_config: done config len = 349
debug2: parse_server_config: config /etc/ssh/sshd_config len 349
debug3: /etc/ssh/sshd_config:39 setting PubkeyAuthentication yes
debug3: /etc/ssh/sshd_config:40 setting TrustedUserCAKeys /etc/ssh/ca.pub
debug3: /etc/ssh/sshd_config:44 setting AuthorizedKeysFile .ssh/authorized_keys
debug3: /etc/ssh/sshd_config:60 setting PasswordAuthentication no
debug3: /etc/ssh/sshd_config:61 setting PermitEmptyPasswords no
debug3: /etc/ssh/sshd_config:64 setting KbdInteractiveAuthentication yes
debug3: /etc/ssh/sshd_config:118 setting Subsystem sftp /usr/libexec/openssh/sftp-server
debug1: sshd version OpenSSH_7.4, OpenSSL 1.0.2k-fips 26 Jan 2017
debug1: private host key #0: ssh-rsa SHA256:hp3aeqNIbNsm3Go1vVcFJ4BxpME1At1S548JUxgkYnQ
debug1: key_load_private: No such file or directory
debug1: key_load_public: No such file or directory
Could not load host key: /etc/ssh/ssh_host_dsa_key
debug1: private host key #2: ecdsa-sha2-nistp256 SHA256:lJGDucK20d0Ng5QPUGaLtyF2wKgw0LnOu8yIno/qc3s
debug1: private host key #3: ssh-ed25519 SHA256:sLq1CZONobN4r2GZPC5oXdRgMw33veo7sdeBu8NiFyg
debug1: rexec_argv[0]='/usr/sbin/sshd'
debug1: rexec_argv[1]='-ddd'
debug3: oom_adjust_setup
debug1: Set /proc/self/oom_score_adj from 0 to -1000
debug2: fd 3 setting O_NONBLOCK
debug1: Bind to port 22 on 0.0.0.0.
Server listening on 0.0.0.0 port 22.
debug2: fd 4 setting O_NONBLOCK
debug3: sock_set_v6only: set socket 4 IPV6_V6ONLY
debug1: Bind to port 22 on ::.
Server listening on :: port 22.
debug3: fd 5 is not O_NONBLOCK
debug1: Server will not fork when running in debugging mode.
debug3: send_rexec_state: entering fd = 8 config len 349
debug3: ssh_msg_send: type 0
debug3: send_rexec_state: done
debug1: rexec start in 5 out 5 newsock 5 pipe -1 sock 8
debug1: inetd sockets after dupping: 3, 3
Connection from 192.168.2.52 port 50574 on 192.168.2.10 port 22
debug1: Client protocol version 2.0; client software version OpenSSH_8.7
debug1: match: OpenSSH_8.7 pat OpenSSH* compat 0x04000000
debug1: Local version string SSH-2.0-OpenSSH_7.4
debug1: Enabling compatibility mode for protocol 2.0
debug2: fd 3 setting O_NONBLOCK
debug3: ssh_sandbox_init: preparing seccomp filter sandbox
debug2: Network child is on pid 2451
debug3: preauth child monitor started
debug1: SELinux support enabled [preauth]
debug3: ssh_selinux_change_context: setting context from 'unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023' to 'unconfined_u:unconfined_r:sshd_net_t:s0-s0:c0.c1023' [preauth]
debug3: ssh_selinux_change_context: setcon unconfined_u:unconfined_r:sshd_net_t:s0-s0:c0.c1023 from unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 failed with Invalid argument [preauth]
debug3: privsep user:group 74:74 [preauth]
debug1: permanently_set_uid: 74/74 [preauth]
debug3: ssh_sandbox_child: setting PR_SET_NO_NEW_PRIVS [preauth]
debug3: ssh_sandbox_child: attaching seccomp filter program [preauth]
debug1: list_hostkey_types: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519 [preauth]
debug3: send packet: type 20 [preauth]
debug1: SSH2_MSG_KEXINIT sent [preauth]
debug3: receive packet: type 20 [preauth]
debug1: SSH2_MSG_KEXINIT received [preauth]
debug2: local server KEXINIT proposal [preauth]
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 [preauth]
debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519 [preauth]
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc,blowfish-cbc,cast128-cbc,3des-cbc [preauth]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc,blowfish-cbc,cast128-cbc,3des-cbc [preauth]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1 [preauth]
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1 [preauth]
debug2: compression ctos: none,[email protected] [preauth]
debug2: compression stoc: none,[email protected] [preauth]
debug2: languages ctos: [preauth]
debug2: languages stoc: [preauth]
debug2: first_kex_follows 0 [preauth]
debug2: reserved 0 [preauth]
debug2: peer client KEXINIT proposal [preauth]
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ext-info-c [preauth]
debug2: host key algorithms: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],rsa-sha2-512,rsa-sha2-256,ssh-rsa [preauth]
debug2: ciphers ctos: [email protected],[email protected],aes256-ctr,[email protected],aes128-ctr [preauth]
debug2: ciphers stoc: [email protected],[email protected],aes256-ctr,[email protected],aes128-ctr [preauth]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha1,[email protected],hmac-sha2-512 [preauth]
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha1,[email protected],hmac-sha2-512 [preauth]
debug2: compression ctos: none,[email protected],zlib [preauth]
debug2: compression stoc: none,[email protected],zlib [preauth]
debug2: languages ctos: [preauth]
debug2: languages stoc: [preauth]
debug2: first_kex_follows 0 [preauth]
debug2: reserved 0 [preauth]
debug1: kex: algorithm: curve25519-sha256 [preauth]
debug1: kex: host key algorithm: ssh-ed25519 [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=32 dh_need=32 [preauth]
debug3: mm_request_send entering: type 120 [preauth]
debug3: mm_request_receive_expect entering: type 121 [preauth]
debug3: mm_request_receive entering [preauth]
debug3: mm_request_receive entering
debug3: monitor_read: checking request 120
debug3: mm_request_send entering: type 121
debug1: kex: curve25519-sha256 need=32 dh_need=32 [preauth]
debug3: mm_request_send entering: type 120 [preauth]
debug3: mm_request_receive_expect entering: type 121 [preauth]
debug3: mm_request_receive entering [preauth]
debug3: mm_request_receive entering
debug3: monitor_read: checking request 120
debug3: mm_request_send entering: type 121
debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth]
debug3: receive packet: type 30 [preauth]
debug3: mm_key_sign entering [preauth]
debug3: mm_request_send entering: type 6 [preauth]
debug3: mm_key_sign: waiting for MONITOR_ANS_SIGN [preauth]
debug3: mm_request_receive_expect entering: type 7 [preauth]
debug3: mm_request_receive entering [preauth]
debug3: mm_request_receive entering
debug3: monitor_read: checking request 6
debug3: mm_answer_sign
debug3: mm_answer_sign: hostkey proof signature 0x55cbcccd2b70(83)
debug3: mm_request_send entering: type 7
debug2: monitor_read: 6 used once, disabling now
debug3: send packet: type 31 [preauth]
debug3: send packet: type 21 [preauth]
debug2: set_newkeys: mode 1 [preauth]
debug1: rekey after 4294967296 blocks [preauth]
debug1: SSH2_MSG_NEWKEYS sent [preauth]
debug1: expecting SSH2_MSG_NEWKEYS [preauth]
debug3: send packet: type 7 [preauth]
debug3: receive packet: type 21 [preauth]
debug1: SSH2_MSG_NEWKEYS received [preauth]
debug2: set_newkeys: mode 0 [preauth]
debug1: rekey after 4294967296 blocks [preauth]
debug1: KEX done [preauth]
debug3: receive packet: type 5 [preauth]
debug3: send packet: type 6 [preauth]
debug3: receive packet: type 50 [preauth]
debug1: userauth-request for user matt service ssh-connection method none [preauth]
debug1: attempt 0 failures 0 [preauth]
debug3: mm_getpwnamallow entering [preauth]
debug3: mm_request_send entering: type 8 [preauth]
debug3: mm_getpwnamallow: waiting for MONITOR_ANS_PWNAM [preauth]
debug3: mm_request_receive_expect entering: type 9 [preauth]
debug3: mm_request_receive entering [preauth]
debug3: mm_request_receive entering
debug3: monitor_read: checking request 8
debug3: mm_answer_pwnamallow
debug3: Trying to reverse map address 192.168.2.52.
debug2: parse_server_config: config reprocess config len 349
debug3: auth_shadow_acctexpired: today 19015 sp_expire -1 days left -19016
debug3: account expiration disabled
debug3: mm_answer_pwnamallow: sending MONITOR_ANS_PWNAM: 1
debug3: mm_request_send entering: type 9
debug2: monitor_read: 8 used once, disabling now
debug2: input_userauth_request: setting up authctxt for matt [preauth]
debug3: mm_inform_authserv entering [preauth]
debug3: mm_request_send entering: type 4 [preauth]
debug3: mm_inform_authrole entering [preauth]
debug3: mm_request_send entering: type 80 [preauth]
debug2: input_userauth_request: try method none [preauth]
debug3: userauth_finish: failure partial=0 next methods="publickey,keyboard-interactive" [preauth]
debug3: send packet: type 51 [preauth]
debug3: mm_request_receive entering
debug3: monitor_read: checking request 4
debug3: mm_answer_authserv: service=ssh-connection, style=
debug2: monitor_read: 4 used once, disabling now
debug3: mm_request_receive entering
debug3: monitor_read: checking request 80
debug3: mm_answer_authrole: role=
debug2: monitor_read: 80 used once, disabling now
debug3: receive packet: type 50 [preauth]
debug1: userauth-request for user matt service ssh-connection method publickey [preauth]
debug1: attempt 1 failures 0 [preauth]
debug2: input_userauth_request: try method publickey [preauth]
debug1: userauth_pubkey: test whether pkalg/pkblob are acceptable for RSA SHA256:RAxiw1VaHXlE3rjagbQDt1dMs7dJWxECftlJbEW0zqg [preauth]
debug3: mm_key_allowed entering [preauth]
debug3: mm_request_send entering: type 22 [preauth]
debug3: mm_key_allowed: waiting for MONITOR_ANS_KEYALLOWED [preauth]
debug3: mm_request_receive_expect entering: type 23 [preauth]
debug3: mm_request_receive entering [preauth]
debug3: mm_request_receive entering
debug3: monitor_read: checking request 22
debug3: mm_answer_keyallowed entering
debug3: mm_answer_keyallowed: key_from_blob: 0x55cbcccd4e10
debug1: temporarily_use_uid: 1000/1000 (e=0/0)
debug1: trying public key file /home/matt/.ssh/authorized_keys
debug1: Could not open authorized keys '/home/matt/.ssh/authorized_keys': No such file or directory
debug1: restore_uid: 0/0
debug3: mm_answer_keyallowed: key 0x55cbcccd4e10 is not allowed
Failed publickey for matt from 192.168.2.52 port 50574 ssh2: RSA SHA256:RAxiw1VaHXlE3rjagbQDt1dMs7dJWxECftlJbEW0zqg
debug3: mm_request_send entering: type 23
debug2: userauth_pubkey: authenticated 0 pkalg rsa-sha2-256 [preauth]
debug3: userauth_finish: failure partial=0 next methods="publickey,keyboard-interactive" [preauth]
debug3: send packet: type 51 [preauth]
debug3: receive packet: type 50 [preauth]
debug1: userauth-request for user matt service ssh-connection method keyboard-interactive [preauth]
debug1: attempt 2 failures 1 [preauth]
debug2: input_userauth_request: try method keyboard-interactive [preauth]
debug1: keyboard-interactive devs [preauth]
debug1: auth2_challenge: user=matt devs= [preauth]
debug1: kbdint_alloc: devices '' [preauth]
debug2: auth2_challenge_start: devices [preauth]
debug3: userauth_finish: failure partial=0 next methods="publickey,keyboard-interactive" [preauth]
debug3: send packet: type 51 [preauth]
Connection closed by 192.168.2.52 port 50574 [preauth]
debug1: do_cleanup [preauth]
debug3: mm_request_send entering: type 124 [preauth]
debug3: mm_request_send entering: type 122 [preauth]
debug3: mm_request_receive_expect entering: type 123 [preauth]
debug3: mm_request_receive entering [preauth]
debug3: mm_request_receive entering
debug3: monitor_read: checking request 124
debug3: mm_request_receive entering
debug3: monitor_read: checking request 122
debug3: mm_request_send entering: type 123
debug1: monitor_read_log: child log fd closed
debug3: mm_request_receive entering
debug1: do_cleanup
debug1: Killing privsep child 2451
这里有什么东西可以帮助我了解为什么该密钥无法通过身份验证吗？我似乎无法弄清楚。我能想到的唯一潜在问题是密钥 B 持有者的用户名不是“matt”，但由于原则是，并且指定
ssh matt@centos7vm我不认为这会成为问题，因为它适用于每个 CentOS 9我的VM毫无故障。感谢您的帮助。
更新：我还可以使用此 sshd_config 文件进入 Ubuntu 虚拟机，因此该问题至少似乎是 CentOS 7 特有的。