Analysing the SSH Login and Logout Process

SSH Login Process and SSH Logout Process – Analysis

[email protected]:~# packet_write_wait: Connection to 172.16.149.32 port 22: Broken pipe

[email protected] ~ % ssh kali -vvv

OpenSSH_7.9p1, LibreSSL 2.7.3

debug1: Reading configuration data /Users/krishnag/.ssh/config

debug1: /Users/krishnag/.ssh/config line 19: Applying options for kali

debug1: Reading configuration data /etc/ssh/ssh_config

debug1: /etc/ssh/ssh_config line 48: Applying options for *

debug2: resolve_canonicalize: hostname 172.16.149.32 is address

debug2: ssh_connect_direct

debug1: Connecting to 172.16.149.32 [172.16.149.32] port 22.

debug1: Connection established.

debug1: identity file /Users/krishnag/.ssh/id_rsa type -1

debug1: identity file /Users/krishnag/.ssh/id_rsa-cert type -1

debug1: identity file /Users/krishnag/.ssh/id_dsa type -1

debug1: identity file /Users/krishnag/.ssh/id_dsa-cert type -1

debug1: identity file /Users/krishnag/.ssh/id_ecdsa type -1

debug1: identity file /Users/krishnag/.ssh/id_ecdsa-cert type -1

debug1: identity file /Users/krishnag/.ssh/id_ed25519 type 3

debug1: identity file /Users/krishnag/.ssh/id_ed25519-cert type -1

debug1: identity file /Users/krishnag/.ssh/id_xmss type -1

debug1: identity file /Users/krishnag/.ssh/id_xmss-cert type -1

debug1: Local version string SSH-2.0-OpenSSH_7.9

debug1: Remote protocol version 2.0, remote software version OpenSSH_8.1p1 Debian-1

debug1: match: OpenSSH_8.1p1 Debian-1 pat OpenSSH* compat 0x04000000

debug2: fd 3 setting O_NONBLOCK

debug1: Authenticating to 172.16.149.32:22 as ‘root’

debug3: hostkeys_foreach: reading file “/Users/krishnag/.ssh/known_hosts”

debug3: record_hostkey: found key type ECDSA in file /Users/krishnag/.ssh/known_hosts:2

debug3: load_hostkeys: loaded 1 keys from 172.16.149.32

debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],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,[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],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],[email protected],[email protected],ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa

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: 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

debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256,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]

debug2: compression stoc: none,[email protected]

debug2: languages ctos: 

debug2: languages stoc: 

debug2: first_kex_follows 0 

debug2: reserved 0 

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

debug3: send packet: type 30

debug1: expecting SSH2_MSG_KEX_ECDH_REPLY

debug3: receive packet: type 31

debug1: Server host key: ecdsa-sha2-nistp256 SHA256:2lsoza5yUzOHdFUBUovBsp6DzghSOYy9LqEv7WACtKI

debug3: hostkeys_foreach: reading file “/Users/krishnag/.ssh/known_hosts”

debug3: record_hostkey: found key type ECDSA in file /Users/krishnag/.ssh/known_hosts:2

debug3: load_hostkeys: loaded 1 keys from 172.16.149.32

debug1: Host ‘172.16.149.32’ is known and matches the ECDSA host key.

debug1: Found key in /Users/krishnag/.ssh/known_hosts:2

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: /Users/krishnag/.ssh/id_ed25519 ED25519 SHA256:HRkHKyrGENGnh9+b+CiNDOq6EV/lVNnzuIDanKZVF9c agent

debug1: Will attempt key: krishnag.me ED25519 SHA256:WpT3yHWidjxPaFXFHlhe9OSwfAFOF9hhP1qzqIi2qKs agent

debug1: Will attempt key: /Users/krishnag/.ssh/id_rsa 

debug1: Will attempt key: /Users/krishnag/.ssh/id_dsa 

debug1: Will attempt key: /Users/krishnag/.ssh/id_ecdsa 

debug1: Will attempt key: /Users/krishnag/.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=<ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521>

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

debug3: start over, passed a different list publickey,password

debug3: preferred 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: /Users/krishnag/.ssh/id_ed25519 ED25519 SHA256:HRkHKyrGENGnh9+b+CiNDOq6EV/lVNnzuIDanKZVF9c agent

debug3: send packet: type 50

debug2: we sent a publickey packet, wait for reply

debug3: receive packet: type 60

debug1: Server accepts key: /Users/krishnag/.ssh/id_ed25519 ED25519 SHA256:HRkHKyrGENGnh9+b+CiNDOq6EV/lVNnzuIDanKZVF9c agent

debug3: sign_and_send_pubkey: ED25519 SHA256:HRkHKyrGENGnh9+b+CiNDOq6EV/lVNnzuIDanKZVF9c

debug3: sign_and_send_pubkey: signing using ssh-ed25519

debug3: send packet: type 50

debug3: receive packet: type 52

debug1: Authentication succeeded (publickey).

Authenticated to 172.16.149.132 ([172.16.149.132]: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 80

debug1: client_input_global_request: rtype [email protected] want_reply 0

debug3: receive packet: type 4

debug1: Remote: /root/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding

debug3: receive packet: type 4

debug1: Remote: /root/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding

debug3: receive packet: type 91

debug2: channel_input_open_confirmation: channel 0: callback start

debug2: fd 3 setting TCP_NODELAY

debug3: ssh_packet_set_tos: set IP_TOS 0x48

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 TMPDIR

debug3: Ignored env XPC_FLAGS

debug3: Ignored env TERM_PROGRAM_VERSION

debug3: Ignored env TERM_PROGRAM

debug3: Ignored env XPC_SERVICE_NAME

debug3: Ignored env TERM_SESSION_ID

debug3: Ignored env TERM

debug3: Ignored env SSH_AUTH_SOCK

debug3: Ignored env SHELL

debug3: Ignored env HOME

debug3: Ignored env LOGNAME

debug3: Ignored env USER

debug3: Ignored env PATH

debug3: Ignored env SHLVL

debug3: Ignored env PWD

debug3: Ignored env OLDPWD

debug1: Sending env LC_CTYPE = UTF-8

debug2: channel 0: request env confirm 0

debug3: send packet: type 98

debug3: Ignored env _

debug3: Ignored env __CF_USER_TEXT_ENCODING

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

Linux kali 5.3.0-kali3-amd64 #1 SMP Debian 5.3.15-1kali1 (2019-12-09) x86_64

The programs included with the Kali GNU/Linux system are free software;

the exact distribution terms for each program are described in the

individual files in /usr/share/doc/*/copyright.

Kali GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent

permitted by applicable law.

Last login: Mon Dec 23 05:01:22 2019 from 172.16.169.1

[email protected]:~

[email protected]:~# debug3: send packet: type 1

packet_write_wait: Connection to 172.16.149.32 port 22: Broken pipe

[email protected] ~ %       

[email protected]:~# exit

[email protected]:~# exitdebug3: 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 [email protected] reply 0

debug2: channel 0: rcvd eow

debug2: channel 0: chan_shutdown_read (i0 o0 sock -1 wfd 5 efd 7 [write])

debug2: channel 0: input open -> closed

debug3: receive packet: type 96

debug2: channel 0: rcvd eof

debug2: channel 0: output open -> drain

debug3: receive packet: type 97

debug2: channel 0: rcvd close

debug3: channel 0: will not send data after close

logout

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 6 efd 7 [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/-1/7 sock -1 cc -1)

debug3: send packet: type 1

debug3: fd 1 is not O_NONBLOCK

Connection to 172.16.149.32 closed.

Transferred: sent 5692, received 157396 bytes, in 365.7 seconds

Bytes per second: sent 15.6, received 430.4

debug1: Exit status 0