Paramiko - 错误的身份验证类型 [Cisco SG-300 交换机] [已关闭]

Question

我在以下链接上通过 ssh 使用配置脚本。脚本并不重要，重要的是导入 parmaiko 模块。但我添加了一个链接：

https://github.com/enessanal/NetConfPy/blob/master/netconf.py

以及相关代码：

import paramiko
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
try:
    ssh.connect(hostname=host,port=port,username=username,password=password,timeout=timeout)
except Exception as exception:
    print(str(exception))

该脚本可在所有 Linux 设备上成功运行，包括旧型号 HP 交换机，但一台设备 Cisco SG-300 交换机除外。我想我明白这个问题了。问题出在 Switch 上。 这种类型的开关表现不同。当使用 ssh 命令或通过 Putty 尝试正常的 ssh 连接时，会出现两种身份验证机制。第一个是“登录身份”，另一个是“用户名”。我们对第二个感兴趣。但是程序（paramiko客户端）无法绕过“登录为”部分。并每次都会抛出“错误的身份验证类型”异常。 我怎么解决这个问题？或者还有另一种通过 ssh 连接自动配置的方法吗？

调试信息：

OpenSSH_7.9p1 Debian-1, OpenSSL 1.1.1  11 Sep 2018

debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: resolve_canonicalize: hostname 10.39.31.11 is address
debug2: ssh_connect_direct
debug1: Connecting to 10.39.31.11 [10.39.31.11] port 22.
debug1: Connection established.
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: identity file /root/.ssh/id_ed25519 type -1
debug1: identity file /root/.ssh/id_ed25519-cert type -1
debug1: identity file /root/.ssh/id_xmss type -1
debug1: identity file /root/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.9p1 Debian-1
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.3p1.RL
debug1: match: OpenSSH_7.3p1.RL pat OpenSSH_7.0*,OpenSSH_7.1*,OpenSSH_7.2*,OpenSSH_7.3*,OpenSSH_7.4*,OpenSSH_7.5*,OpenSSH_7.6*,OpenSSH_7.7* compat 0x04000002
debug2: fd 5 setting O_NONBLOCK
debug1: Authenticating to 10.39.31.11:22 as 'root'
debug3: hostkeys_foreach: reading file "/root/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /root/.ssh/known_hosts:9
debug3: load_hostkeys: loaded 1 keys from 10.39.31.11
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
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-group14-sha256,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: [email protected],[email protected],[email protected],rsa-sha2-512,rsa-sha2-256,ssh-rsa,[email protected],[email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
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
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
debug2: compression ctos: none,[email protected],zlib
debug2: compression stoc: none,[email protected],zlib
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1,diffie-hellman-group14-sha1
debug2: host key algorithms: ssh-rsa,ssh-dss
debug2: ciphers ctos: aes128-ctr,aes192-ctr,aes256-ctr,[email protected]
debug2: ciphers stoc: aes128-ctr,aes192-ctr,aes256-ctr,[email protected]
debug2: MACs ctos: hmac-sha1
debug2: MACs stoc: hmac-sha1
debug2: compression ctos: none
debug2: compression stoc: none
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug1: kex: algorithm: diffie-hellman-group14-sha1
debug1: kex: host key algorithm: ssh-rsa
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: sending SSH2_MSG_KEXDH_INIT
debug2: bits set: 1001/2048
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEXDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ssh-rsa SHA256:dS79N4clCGySrehvWW5kpCRgm3VXlYClD0pyoaYSNoQ
debug3: hostkeys_foreach: reading file "/root/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /root/.ssh/known_hosts:9
debug3: load_hostkeys: loaded 1 keys from 10.34.35.11
debug1: Host '10.39.31.11' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:9
debug2: bits set: 1068/2048
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug1: Will attempt key: /root/.ssh/id_rsa 
debug1: Will attempt key: /root/.ssh/id_dsa 
debug1: Will attempt key: /root/.ssh/id_ecdsa 
debug1: Will attempt key: /root/.ssh/id_ed25519 
debug1: Will attempt key: /root/.ssh/id_xmss 
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 52
debug1: Authentication succeeded (none).

Authenticated to 10.39.31.11 ([10.39.31.11]:22).

debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug3: send packet: type 90
debug1: Requesting [email protected]
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: network
debug3: receive packet: type 91
debug2: channel_input_open_confirmation: channel 0: callback start
debug2: fd 5 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IP_TOS 0x08
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug3: send packet: type 98
debug1: Sending environment.
debug3: Ignored env LS_COLORS
debug3: Ignored env SSH_CONNECTION
debug1: Sending env LANG = en_US.UTF-8
debug2: channel 0: request env confirm 0
debug3: send packet: type 98
debug3: Ignored env XDG_SESSION_ID
debug3: Ignored env USER
debug3: Ignored env PWD
debug3: Ignored env HOME
debug3: Ignored env SSH_CLIENT
debug3: Ignored env SSH_TTY
debug3: Ignored env MAIL
debug3: Ignored env TERM
debug3: Ignored env SHELL
debug3: Ignored env SHLVL
debug3: Ignored env LOGNAME
debug3: Ignored env DBUS_SESSION_BUS_ADDRESS
debug3: Ignored env XDG_RUNTIME_DIR
debug3: Ignored env PATH
debug3: Ignored env _
debug2: channel 0: request shell confirm 1
debug3: send packet: type 98
debug2: channel_input_open_confirmation: channel 0: callback done
debug2: channel 0: open confirm rwindow 2097152 rmax 32768
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0




User Name:wrong_credentils_don't_effect_the_logs
Password:***

User Name:cisco
Password:************

Switch1>exit
debug3: receive packet: type 97
debug2: channel 0: rcvd close
debug2: channel 0: output open -> drain
debug2: channel 0: chan_shutdown_read (i0 o1 sock -1 wfd 6 efd 8 [write])
debug2: channel 0: input open -> closed
debug3: channel 0: will not send data after close
debug3: channel 0: will not send data after close
debug2: channel 0: obuf empty
debug2: channel 0: chan_shutdown_write (i3 o1 sock -1 wfd 7 efd 8 [write])
debug2: channel 0: output drain -> closed
debug2: channel 0: almost dead
debug2: channel 0: gc: notify user
debug2: channel 0: gc: user detached
debug2: channel 0: send close
debug3: send packet: type 97
debug2: channel 0: is dead
debug2: channel 0: garbage collecting
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
  #0 client-session (t4 r0 i3/0 o3/0 e[write]/0 fd -1/-1/8 sock -1 cc -1)

debug3: send packet: type 1
debug3: fd 1 is not O_NONBLOCK
Connection to 10.39.31.11 closed.
Transferred: sent 3552, received 2776 bytes, in 28.7 seconds
Bytes per second: sent 123.9, received 96.8
debug1: Exit status -1

还有 paramiko 日志文件：

DEB [20181204-11:25:17.677] thr=1   paramiko.transport: starting thread (client mode): 0x3c1fed0
DEB [20181204-11:25:17.677] thr=1   paramiko.transport: Local version/idstring: SSH-2.0-paramiko_2.4.2
DEB [20181204-11:25:17.695] thr=1   paramiko.transport: Remote version/idstring: SSH-2.0-OpenSSH_7.3p1.RL
INF [20181204-11:25:17.695] thr=1   paramiko.transport: Connected (version 2.0, client OpenSSH_7.3p1.RL)
DEB [20181204-11:25:18.015] thr=1   paramiko.transport: kex algos:['diffie-hellman-group-exchange-sha1', 'diffie-hellman-group1-sha1', 'diffie-hellman-group14-sha1'] server key:['ssh-rsa', 'ssh-dss'] client encrypt:['aes128-ctr', 'aes192-ctr', 'aes256-ctr', '[email protected]'] server encrypt:['aes128-ctr', 'aes192-ctr', 'aes256-ctr', '[email protected]'] client mac:['hmac-sha1'] server mac:['hmac-sha1'] client compress:['none'] server compress:['none'] client lang:[''] server lang:[''] kex follows?False
DEB [20181204-11:25:18.016] thr=1   paramiko.transport: Kex agreed: diffie-hellman-group-exchange-sha1
DEB [20181204-11:25:18.016] thr=1   paramiko.transport: HostKey agreed: ssh-rsa
DEB [20181204-11:25:18.016] thr=1   paramiko.transport: Cipher agreed: aes128-ctr
DEB [20181204-11:25:18.016] thr=1   paramiko.transport: MAC agreed: hmac-sha1
DEB [20181204-11:25:18.016] thr=1   paramiko.transport: Compression agreed: none
DEB [20181204-11:25:18.027] thr=1   paramiko.transport: Got server p (2048 bits)
DEB [20181204-11:25:18.459] thr=1   paramiko.transport: kex engine KexGex specified hash_algo <built-in function openssl_sha1>
DEB [20181204-11:25:18.459] thr=1   paramiko.transport: Switch to new keys ...
DEB [20181204-11:25:18.460] thr=2   paramiko.transport: Adding ssh-rsa host key for 10.39.31.11: b'd6d12a09458873202a0e271b90d38a7d'
DEB [20181204-11:25:18.936] thr=1   paramiko.transport: userauth is OK
DEB [20181204-11:25:18.940] thr=1   paramiko.transport: Authentication type (password) not permitted.
DEB [20181204-11:25:18.940] thr=1   paramiko.transport: Allowed methods: ['']
DEB [20181204-11:25:18.941] thr=1   paramiko.transport: EOF in transport thread
DEB [20181204-11:25:18.946] thr=3   paramiko.transport: starting thread (client mode): 0x386b0f0
DEB [20181204-11:25:18.947] thr=3   paramiko.transport: Local version/idstring: SSH-2.0-paramiko_2.4.2
DEB [20181204-11:25:19.245] thr=3   paramiko.transport: Remote version/idstring: SSH-2.0-OpenSSH_7.3p1.RL
INF [20181204-11:25:19.245] thr=3   paramiko.transport: Connected (version 2.0, client OpenSSH_7.3p1.RL)
DEB [20181204-11:25:19.566] thr=3   paramiko.transport: kex algos:['diffie-hellman-group-exchange-sha1', 'diffie-hellman-group1-sha1', 'diffie-hellman-group14-sha1'] server key:['ssh-rsa', 'ssh-dss'] client encrypt:['aes128-ctr', 'aes192-ctr', 'aes256-ctr', '[email protected]'] server encrypt:['aes128-ctr', 'aes192-ctr', 'aes256-ctr', '[email protected]'] client mac:['hmac-sha1'] server mac:['hmac-sha1'] client compress:['none'] server compress:['none'] client lang:[''] server lang:[''] kex follows?False
DEB [20181204-11:25:19.566] thr=3   paramiko.transport: Kex agreed: diffie-hellman-group-exchange-sha1
DEB [20181204-11:25:19.566] thr=3   paramiko.transport: HostKey agreed: ssh-rsa
DEB [20181204-11:25:19.566] thr=3   paramiko.transport: Cipher agreed: aes128-ctr
DEB [20181204-11:25:19.566] thr=3   paramiko.transport: MAC agreed: hmac-sha1
DEB [20181204-11:25:19.567] thr=3   paramiko.transport: Compression agreed: none
DEB [20181204-11:25:19.576] thr=3   paramiko.transport: Got server p (2048 bits)
DEB [20181204-11:25:19.946] thr=3   paramiko.transport: kex engine KexGex specified hash_algo <built-in function openssl_sha1>
DEB [20181204-11:25:19.946] thr=3   paramiko.transport: Switch to new keys ...
DEB [20181204-11:25:19.947] thr=2   paramiko.transport: Adding ssh-rsa host key for 10.39.31.11: b'd6d12a09458873202a0e271b90d38a7d'
DEB [20181204-11:25:20.486] thr=3   paramiko.transport: userauth is OK
DEB [20181204-11:25:20.491] thr=3   paramiko.transport: Authentication type (password) not permitted.
DEB [20181204-11:25:20.491] thr=3   paramiko.transport: Allowed methods: ['']
DEB [20181204-11:25:20.492] thr=3   paramiko.transport: EOF in transport thread

程序抛出的异常字符串：

[*] Testing connection...
[*] Getting banner...
[+] Banner => SSH-2.0-OpenSSH_7.3p1.RL
[-] Failed to connect => 10.39.31.11:22 (('Bad authentication type', ['']) (allowed_types=['']))
[*] Exiting...

非常感谢。

Answer 1

将以下内容添加到您的 Cisco SG3XX 配置中：

ip ssh password-auth

这将使用 paramiko 期望的 SSH 密码身份验证，而不是使用基于 shell 的身份验证。

Answer 2

服务器（交换机）不支持任何SSH认证方式：

DEB [20181204-11:25:18.940] thr=1   paramiko.transport: Authentication type (password) not permitted.
DEB [20181204-11:25:18.940] thr=1   paramiko.transport: Allowed methods: ['']

它实际上使用简单的 I/O（类似于 Telnet）来提示输入凭据。

当您指示 Paramiko 使用标准 SSH 密码身份验证（通过向

SSHClient.connect()

提供密码）时，它会失败。

Paramiko（与

ssh

相反）不支持“无”身份验证（或不直接支持）。

虽然这可能有效：

• 请勿向

  SSHClient.connect()

  提供密码

• SSHClient.connect()

  应该失败，并显示

  SSHException('No authentication methods available')

  - 吞下这个异常

• 现在您已连接到服务器，但尚未经过身份验证。要使用“无”SSH 身份验证进行身份验证，请调用

  Transport.auth_none()

  :

  ssh.get_transport().auth_none(username)
  

现在就 SSH 而言，您应该已经“经过身份验证”。同样，即使在您收到任何凭据提示之前，

ssh

也相信它已通过身份验证：

debug1: Authentication succeeded (none).

Authenticated to 10.39.31.11 ([10.39.31.11]:22).

...

User Name:wrong_credentils_don't_effect_the_logs
Password:***

User Name:cisco
Password:************

---

然后，如果您尝试使用

SSHClient.invoke_shell()

打开“shell”（也许您尝试使用

SSHClient.exec_command()

执行命令 - 尽管我假设服务器不支持此接口），服务器将提示您使用 I/O 输入用户名和密码。

尝试以这种方式提供凭据：

channel = ssh.invoke_shell()
channel.send(username + "\n")
channel.send(password + "\n")

（如果服务器不接受立即提供的凭据，您可能需要在提供凭据之前等待提示 [expect-like]）。

---

强制警告：请勿使用

AutoAddPolicy

，除非您不关心安全性。这样您就会失去针对 MITM 攻击的保护。
正确的解决方案请参阅Paramiko“未知服务器”