Can’t do socket-based activation of sshd

[nisbet-hubbard]

Checklist

• Using latest version on the App Store
• Read the docs
• Searched for existing GitHub issues

Configuration

OpenSSH9.8 on remote machine.

Using Fedora’s sshd.socket and [email protected]: https://src.fedoraproject.org/rpms/openssh/tree/rawhide

Describe the bug

With sshd.socket enabled and sshd.service inactive, I can log into the machine from the ssh client of OpenSSH but not from Blink. Instead, a blank screen appears, followed by the top blue bar saying Blink has been disconnected for x seconds.

The log has the usual Accepted publickey for user from … entry, but it’s then followed by Connection closed by … after three seconds.

I can log in from Blink only when sshd.socket is disabled and sshd.service is active.

[carloscabanero]

Just to clarify where the issue is as we may be mixing ssh - mosh issues. The top blue bar only shows for Mosh, meaning that Mosh was not able to connect to the remote. If that bar was shown, the flow up to that point was that the ssh connection succeeded and it was able to start mosh-server and grab the result, then ssh disconnected, and mosh-client was not able to connect to the mosh-server with the obtained parameters. So it would be an issue with the server not exposing the UDP ports for mosh.

Could you send a dump of ssh -vvvv so we can pin-point at what step the issue is?

[nisbet-hubbard]

Certainly!

Setting up connection callbacks.
Starting connection to xxx.xxx.xx.xx
ssh_connect: libssh 0.9.8 (c) 2003-2021 Aris Adamantiadis, Andreas Schneider and libssh contributors. Distributed under the LGPL, please refer to COPYING file for information about your rights, using threading threads_pthread
ssh_connect: Socket connecting, now waiting for the callbacks to work
ssh_connect: current state : 1
-[IO stream:handleEvent:]: Received POLLOUT in connecting state
socket_callback_connected: Socket connection callback: 1 (0)
ssh_client_connection_callback: session_state=2
Starting connection to xxx.xxx.xx.xx
ssh_connect: current state : 2
callback_receive_banner: Received banner: SSH-2.0-OpenSSH_9.8
ssh_client_connection_callback: session_state=3
ssh_client_connection_callback: SSH server banner: SSH-2.0-OpenSSH_9.8
ssh_analyze_banner: Analyzing banner: SSH-2.0-OpenSSH_9.8
ssh_analyze_banner: We are talking to an OpenSSH client version: 9.8 (90800)
ssh_client_select_hostkeys: Order of wanted host keys: "ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-dss"
ssh_known_hosts_read_entries: Failed to open the known_hosts file '/etc/ssh/ssh_known_hosts': No such file or directory
ssh_client_select_hostkeys: Algorithms found in known_hosts files: "ssh-ed25519"
ssh_client_select_hostkeys: Changing host key method to "ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-dss"
ssh_send_kex: Sending KEXINIT packet, first_kex_packet_follows = 0
ssh_list_kex: kex algos: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group18-sha512,diffie-hellman-group16-sha512,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,ext-info-c,[email protected]
ssh_list_kex: server host key algo: ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-dss
ssh_list_kex: encryption client->server: [email protected],[email protected],aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-cbc
ssh_list_kex: encryption server->client: [email protected],[email protected],aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-cbc
ssh_list_kex: mac algo client->server: [email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
ssh_list_kex: mac algo server->client: [email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
ssh_list_kex: compression algo client->server: [email protected],zlib,none
ssh_list_kex: compression algo server->client: [email protected],zlib,none
ssh_list_kex: languages client->server: 
ssh_list_kex: languages server->client: 
packet_send2: packet: wrote [type=20, len=1044, padding_size=5, comp=1038, payload=1038]
ssh_send_kex: SSH_MSG_KEXINIT sent
Starting connection to xxx.xxx.xx.xx
ssh_connect: current state : 4
ssh_packet_socket_callback: packet: read type 20 [len=1068,padding=5,comp=1062,payload=1062]
ssh_packet_process: Dispatching handler for packet type 20
ssh_packet_kexinit: KEXINIT received
ssh_packet_kexinit: Server supports strict kex, enabling.
ssh_client_connection_callback: session_state=5
ssh_list_kex: kex algos: [email protected],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,ext-info-s,[email protected]
ssh_list_kex: server host key algo: ssh-ed25519
ssh_list_kex: encryption client->server: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
ssh_list_kex: encryption server->client: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
ssh_list_kex: mac algo client->server: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
ssh_list_kex: mac algo server->client: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
ssh_list_kex: compression algo client->server: none,[email protected]
ssh_list_kex: compression algo server->client: none,[email protected]
ssh_list_kex: languages client->server: 
ssh_list_kex: languages server->client: 
ssh_kex_select_methods: Negotiated curve25519-sha256,ssh-ed25519,[email protected],[email protected],aead-gcm,aead-gcm,[email protected],[email protected],,
dh_handshake: dh_handshake_state = 0, kex_type = 9
packet_send2: packet: wrote [type=30, len=44, padding_size=6, comp=37, payload=37]
Starting connection to xxx.xxx.xx.xx
ssh_connect: current state : 6
ssh_packet_socket_callback: packet: read type 31 [len=188,padding=8,comp=179,payload=179]
ssh_packet_process: Dispatching handler for packet type 31
packet_send2: packet: wrote [type=21, len=12, padding_size=10, comp=1, payload=1]
ssh_packet_set_newkeys: called, direction = OUT 
crypt_set_algorithms2: Set output algorithm to [email protected]
crypt_set_algorithms2: Set HMAC output algorithm to aead-gcm
crypt_set_algorithms2: Set input algorithm to [email protected]
crypt_set_algorithms2: Set HMAC input algorithm to aead-gcm
ssh_init_rekey_state: Set rekey after 4294967296 blocks
ssh_init_rekey_state: Set rekey after 4294967296 blocks
ssh_packet_send_newkeys: SSH_MSG_NEWKEYS sent
ssh_packet_socket_callback: Processing 308 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 21 [len=12,padding=10,comp=1,payload=1]
ssh_packet_process: Dispatching handler for packet type 21
ssh_packet_newkeys: Received SSH_MSG_NEWKEYS
ssh_pki_signature_verify: Going to verify a ssh-ed25519 type signature
pki_verify_data_signature: Signature valid
ssh_packet_newkeys: Signature verified and valid
ssh_packet_set_newkeys: called, direction = IN 
ssh_client_connection_callback: session_state=6
ssh_packet_socket_callback: Processing 292 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 7 [len=272,padding=19,comp=252,payload=252]
ssh_packet_process: Dispatching handler for packet type 7
ssh_packet_ext_info: Received SSH_MSG_EXT_INFO
ssh_packet_ext_info: Follows 3 extensions
ssh_packet_ext_info: Extension: server-sig-algs=<ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],rsa-sha2-512,rsa-sha2-256>
Starting connection to xxx.xxx.xx.xx
ssh_connect: current state : 7
Connection succeeded...
Authenticating...
Trying none...
packet_send2: packet: wrote [type=5, len=32, padding_size=14, comp=17, payload=17]
ssh_service_request: Sent SSH_MSG_SERVICE_REQUEST (service ssh-userauth)
ssh_packet_socket_callback: packet: read type 6 [len=32,padding=14,comp=17,payload=17]
ssh_packet_process: Dispatching handler for packet type 6
ssh_packet_service_accept: Received SSH_MSG_SERVICE_ACCEPT
packet_send2: packet: wrote [type=50, len=48, padding_size=12, comp=35, payload=35]
ssh_packet_socket_callback: packet: read type 51 [len=32,padding=7,comp=24,payload=24]
ssh_packet_process: Dispatching handler for packet type 51
ssh_packet_userauth_failure: Access denied for 'none'. Authentication that can continue: publickey,password
ssh_packet_userauth_failure: Access denied for 'none'. Authentication that can continue: publickey,password
Trying publickey...
agent_talk: Request length: 1
ssh_agent_get_ident_count: Answer type: 12, expected answer: 12
ssh_agent_get_ident_count: Agent count: 1
ssh_userauth_agent: Trying identity ssh_host_ed25519_key
ssh_key_algorithm_allowed: Checking ssh-ed25519 with list <[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-dss>
packet_send2: packet: wrote [type=50, len=128, padding_size=16, comp=111, payload=111]
ssh_packet_socket_callback: packet: read type 60 [len=80,padding=8,comp=71,payload=71]
ssh_packet_process: Dispatching handler for packet type 60
ssh_packet_userauth_pk_ok: Received SSH_USERAUTH_PK_OK/INFO_REQUEST/GSSAPI_RESPONSE
ssh_packet_userauth_pk_ok: Assuming SSH_USERAUTH_PK_OK
ssh_userauth_agent: Public key of ssh_host_ed25519_key accepted by server
ssh_key_algorithm_allowed: Checking ssh-ed25519 with list <[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-dss>
agent_talk: Request length: 211
packet_send2: packet: wrote [type=50, len=208, padding_size=9, comp=198, payload=198]
ssh_packet_socket_callback: packet: read type 52 [len=16,padding=14,comp=1,payload=1]
ssh_packet_process: Dispatching handler for packet type 52
ssh_packet_userauth_success: Authentication successful
ssh_packet_userauth_success: Received SSH_USERAUTH_SUCCESS
ssh_packet_userauth_success: Enabling delayed compression OUT
ssh_packet_userauth_success: Enabling delayed compression IN
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=21, in_blocks=21
Connected to xxx.xxx.xx.xx
SHELL Opening channel
channel_open: Creating a channel 43 with 64000 window and 32768 max packet
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=22, in_blocks=22
packet_send2: packet: wrote [type=90, len=32, padding_size=5, comp=26, payload=24]
channel_open: Sent a SSH_MSG_CHANNEL_OPEN type session for channel 43
ssh_packet_socket_callback: packet: read type 80 [len=96,padding=10,comp=85,payload=84]
ssh_packet_process: Dispatching handler for packet type 80
ssh_packet_global_request: Received SSH_MSG_GLOBAL_REQUEST packet
ssh_packet_global_request: UNKNOWN SSH_MSG_GLOBAL_REQUEST [email protected], want_reply = 0
ssh_packet_global_request: The requester doesn't want to know the request failed!
ssh_packet_global_request: Invalid SSH_MSG_GLOBAL_REQUEST packet
ssh_packet_socket_callback: Processing 152 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 4 [len=96,padding=10,comp=85,payload=112]
ssh_packet_process: Dispatching handler for packet type 4
ssh_packet_ignore_callback: Received SSH_MSG_DEBUG packet
ssh_packet_socket_callback: Processing 36 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 4 [len=16,padding=10,comp=5,payload=112]
ssh_packet_process: Dispatching handler for packet type 4
ssh_packet_ignore_callback: Received SSH_MSG_DEBUG packet
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=22, in_blocks=40
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=22, in_blocks=40
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=22, in_blocks=40
SHELL Opening channel
ssh_packet_socket_callback: packet: read type 91 [len=16,padding=4,comp=11,payload=17]
ssh_packet_process: Dispatching handler for packet type 91
ssh_packet_channel_open_conf: Received SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
ssh_packet_channel_open_conf: Received a CHANNEL_OPEN_CONFIRMATION for channel 43:0
ssh_packet_channel_open_conf: Remote window : 0, maxpacket : 32768
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=22, in_blocks=41
SHELL Opening channel
SHELL Request PTY
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=25, in_blocks=44
packet_send2: packet: wrote [type=98, len=48, padding_size=6, comp=41, payload=56]
channel_request: Sent a SSH_MSG_CHANNEL_REQUEST pty-req
ssh_packet_socket_callback: packet: read type 99 [len=16,padding=10,comp=5,payload=5]
ssh_packet_process: Dispatching handler for packet type 99
ssh_packet_channel_success: Received SSH_CHANNEL_SUCCESS on channel (43:0)
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=25, in_blocks=41
SHELL Request PTY
channel_request: Channel request pty-req success
Requesting Env Var LANG
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=27, in_blocks=43
packet_send2: packet: wrote [type=98, len=48, padding_size=18, comp=29, payload=36]
channel_request: Sent a SSH_MSG_CHANNEL_REQUEST env
ssh_packet_socket_callback: packet: read type 100 [len=16,padding=10,comp=5,payload=5]
ssh_packet_process: Dispatching handler for packet type 100
ssh_packet_channel_failure: Received SSH_CHANNEL_FAILURE on channel (43:0)
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=27, in_blocks=41
Requesting Env Var LANG
channel_request: Channel request env failed
Error requesting Env Var LANG
Requesting Env Var TERM
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=43
packet_send2: packet: wrote [type=98, len=16, padding_size=4, comp=11, payload=39]
channel_request: Sent a SSH_MSG_CHANNEL_REQUEST env
ssh_packet_socket_callback: packet: read type 100 [len=16,padding=11,comp=4,payload=5]
ssh_packet_process: Dispatching handler for packet type 100
ssh_packet_channel_failure: Received SSH_CHANNEL_FAILURE on channel (43:0)
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=41
Requesting Env Var TERM
channel_request: Channel request env failed
Error requesting Env Var TERM
SHELL Start
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=41
packet_send2: packet: wrote [type=98, len=32, padding_size=19, comp=12, payload=15]
channel_request: Sent a SSH_MSG_CHANNEL_REQUEST shell
ssh_packet_socket_callback: packet: read type 93 [len=16,padding=6,comp=9,payload=9]
ssh_packet_process: Dispatching handler for packet type 93
channel_rcv_change_window: Adding 2097152 bytes to channel (43:0) (from 0 bytes)
ssh_packet_socket_callback: Processing 136 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 99 [len=16,padding=11,comp=4,payload=5]
ssh_packet_process: Dispatching handler for packet type 99
ssh_packet_channel_success: Received SSH_CHANNEL_SUCCESS on channel (43:0)
ssh_packet_socket_callback: Processing 100 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 94 [len=80,padding=15,comp=64,payload=66]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 57 bytes data in 0 (local win=64000 remote win=2097152)
channel_default_bufferize: placing 57 bytes into channel buffer (stdout)
channel_rcv_data: Channel windows are now (local win=63943 remote win=2097152)
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=45
packet_send2: packet: wrote [type=93, len=16, padding_size=7, comp=8, payload=9]
grow_window: growing window (channel 43:0) to 1280000 bytes
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=45
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=45
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=45
SHELL Start
channel_request: Channel request shell success
ssh_channel_read_timeout: Read (57) buffered : 57 bytes. Window: 1280000
Read 57 async from 0x00000003022a87e0
Bytes Read 57
Resetting demand
Setting up callbacks for Reading
Read 0 async from 0x00000003022a87e0
Setting up callbacks for Reading
Last login: Thu Sep 12 07:28:59 2024 from 84.17.45.206
Connect 57 bytes from stdout 57
Read 0 async from 0x00000003022a87e0
ssh_packet_socket_callback: packet: read type 94 [len=48,padding=10,comp=37,payload=43]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 34 bytes data in 0 (local win=1280000 remote win=2097152)
channel_default_bufferize: placing 34 bytes into channel buffer (stdout)
channel_rcv_data: Channel windows are now (local win=1279966 remote win=2097152)
Data callback
Reading from channel 34 out of 34
Bytes Read 91
Resetting demand
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=47
$ Connect 34 bytes from stdout 91
Read 0 async from 0x00000003022a87e0
Trying to write 1 with window 2097152
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=47
packet_send2: packet: wrote [type=94, len=16, padding_size=8, comp=7, payload=10]
channel_write_common: channel_write wrote 1 bytes
Connect 1 bytes from stdin 91
ssh_packet_socket_callback: packet: read type 94 [len=32,padding=19,comp=12,payload=17]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 8 bytes data in 0 (local win=1279966 remote win=2097151)
channel_default_bufferize: placing 8 bytes into channel buffer (stdout)
channel_rcv_data: Channel windows are now (local win=1279958 remote win=2097151)
Data callback
Reading from channel 8 out of 8
Bytes Read 99
Resetting demand
ssh_packet_socket_callback: Processing 124 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 98 [len=32,padding=11,comp=20,payload=25]
ssh_packet_process: Dispatching handler for packet type 98
channel_rcv_request: received exit-status 0
ssh_packet_socket_callback: Processing 72 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 96 [len=16,padding=10,comp=5,payload=5]
ssh_packet_process: Dispatching handler for packet type 96
channel_rcv_eof: Received eof on channel (43:0)
Received channel EOF event callback
Received channel EOF event callback
logout
ssh_packet_socket_callback: Processing 36 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 97 [len=16,padding=9,comp=6,payload=5]
ssh_packet_process: Dispatching handler for packet type 97
channel_rcv_close: Received close on channel (43:0)
Received channel close event callback
Received channel close event callback
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=49
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=49
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=49
ssh_packet_need_rekey: packet: [data_rekey_needed=0, out_blocks=29, in_blocks=49
Connect 8 bytes from stdout 99
Read -127 async from 0x00000003022a87e0
Received EOF on Channel
Reading complete
Read -127 async from 0x00000003022a87e0
Received EOF on Channel
Reading complete
Read -127 async from 0x00000003022a87e0
Received EOF on Channel
Reading complete
Removing callbacks for Reading
Outstream deinit
Read -127 async from 0x00000003022a87e0
Received EOF on Channel