갑자기 이전에 SSH를 통해 연결했던 컴퓨터에 SSH를 통해 연결할 수 없습니다.
내가 A에서 B로 간다고 가정해보자.
출력을 실행할 때
ssh root@ip_addr_of_B
나는 얻다:
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
ssh -vv root@ip_addr_of_BA에서 실행할 때의 출력
OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 64.103.232.105 [64.103.232.105] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug2: key_type_from_name: unknown key type '-----END'
debug1: identity file /root/.ssh/id_rsa type 1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.3
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_setup: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_setup: found hmac-md5
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
debug2: dh_gen_key: priv key bits set: 124/256
debug2: bits set: 523/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host '64.103.232.105' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:3
debug2: bits set: 522/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /root/.ssh/identity ((nil))
debug2: key: /root/.ssh/id_rsa (0x7f972bb77030)
debug2: key: /root/.ssh/id_dsa ((nil))
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug2: we did not send a packet, disable method
debug1: Next authentication method: gssapi-with-mic
debug1: An invalid name was supplied
Cannot determine realm for numeric host address
debug1: An invalid name was supplied
Cannot determine realm for numeric host address
debug1: An invalid name was supplied
debug1: An invalid name was supplied
debug2: we did not send a packet, disable method
debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/identity
debug1: Offering public key: /root/.ssh/id_rsa
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
debug1: Trying private key: /root/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
다음은 B의 sshd_config 파일이다.
# $OpenBSD: sshd_config,v 1.80 2008/07/02 02:24:18 djm Exp $
# This is the sshd server system-wide configuration file. See
# sshd_config(5) for more information.
# This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin
# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented. Uncommented options change a
# default value.
Port 22
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::
# Disable legacy (protocol version 1) support in the server for new
# installations. In future the default will change to require explicit
# activation of protocol 1
Protocol 2
# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key
# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 1024
# Logging
# obsoletes QuietMode and FascistLogging
#SyslogFacility AUTH
SyslogFacility AUTHPRIV
#LogLevel INFO
# Authentication:
#LoginGraceTime 2m
#PermitRootLogin yes
#StrictModes yes
#MaxAuthTries 6
#MaxSessions 10
#RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile .ssh/authorized_keys
#AuthorizedKeysCommand none
#AuthorizedKeysCommandRunAs nobody
# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes
# To disable tunneled clear text passwords, change to no here!
#PasswordAuthentication yes
#PermitEmptyPasswords no
PasswordAuthentication no
# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes
ChallengeResponseAuthentication no
# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no
#KerberosUseKuserok yes
# GSSAPI options
#GSSAPIAuthentication no
GSSAPIAuthentication yes
#GSSAPICleanupCredentials yes
GSSAPICleanupCredentials yes
#GSSAPIStrictAcceptorCheck yes
#GSSAPIKeyExchange no
# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication. Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
#UsePAM no
UsePAM yes
# Accept locale-related environment variables
AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE
AcceptEnv XMODIFIERS
#AllowAgentForwarding yes
#AllowTcpForwarding yes
#GatewayPorts no
#X11Forwarding no
X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#PrintMotd yes
#PrintLastLog yes
#TCPKeepAlive yes
#UseLogin no
#UsePrivilegeSeparation yes
#PermitUserEnvironment no
#Compression delayed
#ClientAliveInterval 0
#ClientAliveCountMax 3
#ShowPatchLevel no
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10
#PermitTunnel no
#ChrootDirectory none
# no default banner path
#Banner none
# override default of no subsystems
Subsystem sftp /usr/libexec/openssh/sftp-server
# Example of overriding settings on a per-user basis
#Match User anoncvs
# X11Forwarding no
# AllowTcpForwarding no
# ForceCommand cvs server
B의 /var/log/secure에는 다음 줄만 포함됩니다.
server sshd: connection closed by ip_addr_of_A
B에서 A로 SSH를 통해 연결할 수 있습니다. 문제는 A에서 B로 SSH를 연결할 때만 발생합니다. 또한 A에서 B가 아닌 다른 컴퓨터로 SSH를 통해 연결할 수 있습니다.
답변1
분명히 비밀번호 인증이 비활성화되어 있고 SSH 키가 없으며 Kerberos가 구성되지 않았습니다. 로컬로 로그인하거나 직렬 콘솔 또는 KVM을 통해 로그인하거나, 서버급 컴퓨터가 있는 경우 로컬 직렬 포트 또는 그래픽 콘솔 리디렉션에 대한 원격 액세스를 허용하는 관리 인터페이스(BMC)가 있어야 합니다. 이 관점에서 볼 때 당신은 운이 좋지 않습니다.
답변2
다른 사람이 B의 sshd_config를 변경한 것 같습니다. PasswordAuthentication을 yes로 변경하고 서비스를 다시 시작하면 문제가 해결되었습니다.
답변3
Disable login: Prompts on Serial Ports
Configuration Level Level-I
Hardware Platform All
OS Default No
Zone Support Global zone only
Reboot Required No
Solaris Security Toolkit Use the disable-serial-login.fin Finish script.
Scorable Item Yes
Description:
The pmadm command provides service administration for the lower level of the Service
Access Facility hierarchy and can be used to disable the ability to login on a particular port.
이유:
시스템의 직렬 장치에 대한 로그인을 비활성화함으로써: 팁, 무단 사용자가 모뎀, 터미널 및 기타 원격 액세스 장치를 이러한 포트에 연결하여 액세스하는 기능이 제한됩니다. 콘솔 장치의 login: 프롬프트가 다른 메커니즘을 통해 제공되기 때문에 시스템에 대한 콘솔 액세스가 직렬 포트를 통해 제공되는 경우에도 이 작업을 안전하게 수행할 수 있습니다.
해결 방법: 권장 상태를 구현하려면 다음 작업을 수행하십시오.
# pmadm -d -p zsmon -s ttya
# pmadm -d -p zsmon -s ttyb
감사: 시스템이 권장대로 구성되었는지 확인하려면 다음 작업을 수행하십시오.
# pmadm -L | awk -F: '($4 == “ux”) { print $3 }'
ttya
ttyb