[GUACAMOLE-1315] SSH Handshake failed in verbose logging

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.3.0
• Component/s: guacd, guacd-docker
• Environment: Docker version 19.03.12, build 48a66213fe on Ubuntu 20.04.2 LTS 5.4.0-67-generic #75-Ubuntu SMP Fri Feb 19 18:03:38 UTC 2021
• Assignee: Unassigned
• Reporter: Adyanth H
• Created: 26/Mar/21 13:05
• Updated: 18/Nov/21 06:48
• Resolved: 27/Mar/21 18:36

Description

I am trying to connect to an appliance (Cisco FirePower Management Center) using guacd but getting the below error in the logs:

 guacd_1 | guacd[6]: INFO: Creating new client for protocol "ssh"
 guacd_1 | guacd[6]: INFO: Connection ID is "$5cb571ab-7aeb-41ce-a927-c1c7372e1cf1"
 guacd_1 | guacd[19]: DEBUG: Processing instruction: size
 guacd_1 | guacd[19]: DEBUG: Processing instruction: audio
 guacd_1 | guacd[19]: DEBUG: Processing instruction: video
 guacd_1 | guacd[19]: DEBUG: Processing instruction: image
 guacd_1 | guacd[19]: DEBUG: Processing instruction: timezone
 guacd_1 | guacd[19]: DEBUG: Parameter "font-name" omitted. Using default value of "monospace".
 guacd_1 | guacd[19]: DEBUG: Parameter "font-size" omitted. Using default value of 12.
 guacd_1 | guacd[19]: DEBUG: Parameter "color-scheme" omitted. Using default value of "".
 guacd_1 | guacd[19]: DEBUG: Parameter "enable-sftp" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "sftp-root-directory" omitted. Using default value of "/".
 guacd_1 | guacd[19]: DEBUG: Parameter "sftp-disable-download" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "sftp-disable-upload" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "port" omitted. Using default value of "22".
 guacd_1 | guacd[19]: DEBUG: Parameter "read-only" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "typescript-name" omitted. Using default value of "typescript".
 guacd_1 | guacd[19]: DEBUG: Parameter "create-typescript-path" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "recording-name" omitted. Using default value of "recording".
 guacd_1 | guacd[19]: DEBUG: Parameter "recording-exclude-output" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "recording-exclude-mouse" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "recording-include-keys" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "create-recording-path" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "server-alive-interval" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "backspace" omitted. Using default value of 127.
 guacd_1 | guacd[19]: DEBUG: Parameter "terminal-type" omitted. Using default value of "linux".
 guacd_1 | guacd[19]: DEBUG: Parameter "timezone" omitted. Using default value of "Asia/Calcutta".
 guacd_1 | guacd[19]: DEBUG: Parameter "disable-copy" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "disable-paste" omitted. Using default value of 0.
 guacd_1 | guacd[19]: DEBUG: Parameter "wol-send-packet" omitted. Using default value of 0.
 guacd_1 | guacd[19]: INFO: User "@62181b81-346d-4cfb-b185-b402c228485e" joined connection "$5cb571ab-7aeb-41ce-a927-c1c7372e1cf1" (1 users now present)
 guacd_1 | guacd[19]: DEBUG: Client is using protocol version "VERSION_1_3_0"
 guacd_1 | guacd[19]: DEBUG: Successfully connected to host 10.106.107.228, port 22
 guacd_1 | guacd[19]: ERROR: SSH handshake failed.
 guacd_1 | guacd[19]: INFO: User "@62181b81-346d-4cfb-b185-b402c228485e" disconnected (0 users remain)
 guacd_1 | guacd[19]: INFO: Last user of connection "$5cb571ab-7aeb-41ce-a927-c1c7372e1cf1" disconnected
 guacd_1 | guacd[19]: DEBUG: Requesting termination of client...
 guacd_1 | guacd[19]: DEBUG: Client terminated successfully.
 guacd_1 | guacd[6]: INFO: Connection "$5cb571ab-7aeb-41ce-a927-c1c7372e1cf1" removed.

 

Guacd version:

adyanth@ubuntu-server:~/rd-gateway$ docker image ls | grep guacd
guacamole/guacd                                   latest              20e0b499517f        2 months ago        270MB
adyanth@ubuntu-server:~/rd-gateway$

Here is the sshd_config from the server:

admin@fmc:~$ grep '^[^#]' /etc/ssh/sshd_config
Ciphers [e-mail],[e-mail],aes256-ctr,aes128-ctr,aes192-ctr
MACs hmac-sha2-256,hmac-sha2-512,[e-mail],[e-mail]
KexAlgorithms [e-mail],ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256
LoginGraceTime 60
PermitRootLogin no
UsePAM yes
X11Forwarding no
PermitUserEnvironment no
GatewayPorts no
PermitTunnel no
MaxSessions 1
StrictModes yes
Compression delayed
Banner /etc/issue
Subsystem       sftp    /usr/libexec/sftp-server
AllowTcpForwarding no
UseDNS yes
MaxAuthTries 3

admin@fmc:~$ grep admin /etc/passwd
admin:x:100:100::/Volume/home/admin:/usr/bin/clish

 

To the same server from the docker host with verbose ssh logging: 

adyanth@ubuntu-server:~/rd-gateway$ ssh admin@10.106.107.228 -vvvv
OpenSSH_8.2p1 Ubuntu-4ubuntu0.2, OpenSSL 1.1.1f  31 Mar 2020
debug1: Reading configuration data /home/adyanth/.ssh/config
debug3: kex names ok: [diffie-hellman-group1-sha1]
debug3: kex names ok: [diffie-hellman-group1-sha1]
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug2: resolve_canonicalize: hostname 10.106.107.228 is address
debug2: ssh_connect_direct
debug1: Connecting to 10.106.107.228 [10.106.107.228] port 22.
debug1: Connection established.
debug1: identity file /home/adyanth/.ssh/id_rsa type 0
debug1: identity file /home/adyanth/.ssh/id_rsa-cert type -1
debug1: identity file /home/adyanth/.ssh/id_dsa type -1
debug1: identity file /home/adyanth/.ssh/id_dsa-cert type -1
debug1: identity file /home/adyanth/.ssh/id_ecdsa type -1
debug1: identity file /home/adyanth/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/adyanth/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/adyanth/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/adyanth/.ssh/id_ed25519 type -1
debug1: identity file /home/adyanth/.ssh/id_ed25519-cert type -1
debug1: identity file /home/adyanth/.ssh/id_ed25519_sk type -1
debug1: identity file /home/adyanth/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/adyanth/.ssh/id_xmss type -1
debug1: identity file /home/adyanth/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.2
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.6 PKIX[11.0]
debug1: match: OpenSSH_7.6 PKIX[11.0] 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 3 setting O_NONBLOCK
debug1: Authenticating to 10.106.107.228:22 as 'admin'
debug3: hostkeys_foreach: reading file "/home/adyanth/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/adyanth/.ssh/known_hosts:12
debug3: load_hostkeys: loaded 1 keys from 10.106.107.228
debug3: order_hostkeyalgs: prefer hostkeyalgs: [e-mail],[e-mail],[e-mail],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
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,[e-mail],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,ext-info-c
debug2: host key algorithms: [e-mail],[e-mail],[e-mail],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],ssh-ed25519,[e-mail],rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: [e-mail],aes128-ctr,aes192-ctr,aes256-ctr,[e-mail],[e-mail]
debug2: ciphers stoc: [e-mail],aes128-ctr,aes192-ctr,aes256-ctr,[e-mail],[e-mail]
debug2: MACs ctos: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[e-mail],zlib
debug2: compression stoc: none,[e-mail],zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: [e-mail],ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256
debug2: host key algorithms: ssh-rsa,rsa-sha2-256,rsa-sha2-512,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [e-mail],[e-mail],aes256-ctr,aes128-ctr,aes192-ctr
debug2: ciphers stoc: [e-mail],[e-mail],aes256-ctr,aes128-ctr,aes192-ctr
debug2: MACs ctos: hmac-sha2-256,hmac-sha2-512,[e-mail],[e-mail]
debug2: MACs stoc: hmac-sha2-256,hmac-sha2-512,[e-mail],[e-mail]
debug2: compression ctos: none,[e-mail]
debug2: compression stoc: none,[e-mail]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: [e-mail]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: aes128-ctr MAC: [e-mail] compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: [e-mail] compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:GcsfTKMXDuEEdk3gC5twdz9Ncwt7sJtWKYPl/7bkT+0
debug3: hostkeys_foreach: reading file "/home/adyanth/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/adyanth/.ssh/known_hosts:12
debug3: load_hostkeys: loaded 1 keys from 10.106.107.228
debug1: Host '10.106.107.228' is known and matches the ECDSA host key.
debug1: Found key in /home/adyanth/.ssh/known_hosts:12
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out after 4294967296 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 in after 4294967296 blocks
debug1: Will attempt key: /home/adyanth/.ssh/id_rsa RSA SHA256:K57sMyb6omTQ5pHD8XG03vzaQwMeOrMueJe03KhtBUA
debug1: Will attempt key: /home/adyanth/.ssh/id_dsa
debug1: Will attempt key: /home/adyanth/.ssh/id_ecdsa
debug1: Will attempt key: /home/adyanth/.ssh/id_ecdsa_sk
debug1: Will attempt key: /home/adyanth/.ssh/id_ed25519
debug1: Will attempt key: /home/adyanth/.ssh/id_ed25519_sk
debug1: Will attempt key: /home/adyanth/.ssh/id_xmss
debug2: pubkey_prepare: done
debug3: send packet: type 5
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 51
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug3: start over, passed a different list publickey,password,keyboard-interactive
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /home/adyanth/.ssh/id_rsa RSA SHA256:K57sMyb6omTQ5pHD8XG03vzaQwMeOrMueJe03KhtBUA
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Trying private key: /home/adyanth/.ssh/id_dsa
debug3: no such identity: /home/adyanth/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /home/adyanth/.ssh/id_ecdsa
debug3: no such identity: /home/adyanth/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/adyanth/.ssh/id_ecdsa_sk
debug3: no such identity: /home/adyanth/.ssh/id_ecdsa_sk: No such file or directory
debug1: Trying private key: /home/adyanth/.ssh/id_ed25519
debug3: no such identity: /home/adyanth/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: /home/adyanth/.ssh/id_ed25519_sk
debug3: no such identity: /home/adyanth/.ssh/id_ed25519_sk: No such file or directory
debug1: Trying private key: /home/adyanth/.ssh/id_xmss
debug3: no such identity: /home/adyanth/.ssh/id_xmss: No such file or directory
debug2: we did not send a packet, disable method
debug3: authmethod_lookup keyboard-interactive
debug3: remaining preferred: password
debug3: authmethod_is_enabled keyboard-interactive
debug1: Next authentication method: keyboard-interactive
debug2: userauth_kbdint
debug3: send packet: type 50
debug2: we sent a keyboard-interactive packet, wait for reply
debug3: receive packet: type 60
debug2: input_userauth_info_req
debug2: input_userauth_info_req: num_prompts 1
Password:
debug3: send packet: type 61
debug3: receive packet: type 60
debug2: input_userauth_info_req
debug2: input_userauth_info_req: num_prompts 0
debug3: send packet: type 61
debug3: receive packet: type 52
debug1: Authentication succeeded (keyboard-interactive).
Authenticated to 10.106.107.228 ([10.106.107.228]: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 [e-mail]
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: exec
debug3: receive packet: type 80
debug1: client_input_global_request: rtype [e-mail] want_reply 0
debug3: receive packet: type 91
debug2: channel_input_open_confirmation: channel 0: callback start
debug1: X11 forwarding requested but DISPLAY not set
debug2: fd 3 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IP_TOS 0x10
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 SHELL
debug3: Ignored env NVM_INC
debug3: Ignored env PWD
debug3: Ignored env LOGNAME
debug3: Ignored env XDG_SESSION_TYPE
debug3: Ignored env MOTD_SHOWN
debug3: Ignored env HOME
debug1: Sending env LANG = en_US.UTF-8
debug2: channel 0: request env confirm 0
debug3: send packet: type 98
debug3: Ignored env LS_COLORS
debug3: Ignored env AUTOSSH_PORT
debug3: Ignored env SSH_CONNECTION
debug3: Ignored env NVM_DIR
debug3: Ignored env LESSCLOSE
debug3: Ignored env XDG_SESSION_CLASS
debug3: Ignored env TERM
debug3: Ignored env LESSOPEN
debug3: Ignored env USER
debug3: Ignored env SHLVL
debug3: Ignored env NVM_CD_FLAGS
debug3: Ignored env XDG_SESSION_ID
debug3: Ignored env XDG_RUNTIME_DIR
debug3: Ignored env SSH_CLIENT
debug3: Ignored env XDG_DATA_DIRS
debug3: Ignored env PATH
debug3: Ignored env DBUS_SESSION_BUS_ADDRESS
debug3: Ignored env NVM_BIN
debug3: Ignored env SSH_TTY
debug3: Ignored env OLDPWD
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 0 rmax 32768
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug2: channel 0: rcvd adjust 2097152
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0
Last login: Fri Mar 26 12:48:28 2021 from ubuntu-server.adyah.ciscoCopyright 2004-2020, Cisco and/or its affiliates. All rights reserved.
Cisco is a registered trademark of Cisco Systems, Inc.
All other trademarks are property of their respective owners.Cisco Fire Linux OS v6.6.1 (build 14)
Cisco Firepower Management Center for VMWare v6.6.1 (build 91)> exit
debug3: receive packet: type 98
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug3: receive packet: type 98
debug1: client_input_channel_req: channel 0 rtype [e-mail] reply 0
debug2: channel 0: rcvd eow
debug2: channel 0: chan_shutdown_read (i0 o0 sock -1 wfd 4 efd 6 [write])
debug2: channel 0: input open -> closed
debug3: receive packet: type 96
debug2: channel 0: rcvd eof
debug2: channel 0: output open -> drain
debug2: channel 0: obuf empty
debug2: channel 0: chan_shutdown_write (i3 o1 sock -1 wfd 5 efd 6 [write])
debug2: channel 0: output drain -> closed
debug3: receive packet: type 97
debug2: channel 0: rcvd close
debug3: channel 0: will not send data after close
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/-1/6 sock -1 cc -1)debug3: send packet: type 1
debug3: fd 1 is not O_NONBLOCK
Connection to 10.106.107.228 closed.
Transferred: sent 3056, received 2824 bytes, in 3.3 seconds
Bytes per second: sent 930.8, received 860.1
debug1: Exit status 0
adyanth@ubuntu-server:~/rd-gateway$

Please let me know what else would be needed to troubleshoot since I am at a loss seeing just one ERROR level message when something is failing.

Issue Links

• duplicates: GUACAMOLE-1052 Libssh2 has less key exchange methods when compare to libssh.
• is duplicated by: GUACAMOLE-1461 Include libssh2 1.9.0 or later in guacd Docker image