PHP7.3 New ssh generate key pair doesn't work to connect on git

I need some help on a bug a bit strange. We migrated yesterday our production environnement from rh-php72 to rh-php73. The server is a centos 7.7.

Now we have a strange behavior : All key pair generated before 5th October work correctly. So all developers arrived in team before this date can pull, push by ssh without any problem. Our new member of the team arrived the 5 October can’t authenticate on SSH since migration on php7.3.

The new generated ssh key pair seems to be not accepted during authentication by SSH.

Test done

  • I create a new key pair on phabricator : so have one with id 1 (creates a long time ago :slight_smile:) et another with id 195 (created yesterday)
  • When i use key pair:
    • the first: ssh -T git@phabricatorURL -i keypair1 => OK
    • the second: ssh -T git@phabricatorURL -i keypair195 => Permission denied
  • I called ssh-auth.php and extracted the 2 public key
  • then i generate public key with ssh-keygen and private key
  • The two publics keys generated are completely identic so i don’t understand why we get permission denied on the recent key.

Log

  • secure:
    Oct 20 17:38:55 plam0075 sshd[10542]: error: AuthorizedKeysCommand /phabricator-ssh-hook/phabricator-ssh-hook.sh git failed, status 255
    Oct 20 17:38:55 plam0075 sshd[10542]: Connection closed by 172.23.48.206 port 64006 [preauth]
  • ssh -T -vvvv old key pair:
    C:\Users\bmerlier>ssh.exe -T git@it-prod-eu-phabricator.intramatch.eu -i z:\.ssh\id_rsa_phabricator.key -vvv
    OpenSSH_8.0p1, OpenSSL 1.1.1c  28 May 2019
    debug1: Reading configuration data /etc/ssh/ssh_config
    debug2: resolving "it-prod-eu-phabricator.intramatch.eu" port 22
    debug2: ssh_connect_direct
    debug1: Connecting to it-prod-eu-phabricator.intramatch.eu [172.23.80.12] port 22.
    debug1: Connection established.
    debug1: identity file z:\\.ssh\\id_rsa_phabricator.key type -1
    debug1: identity file z:\\.ssh\\id_rsa_phabricator.key-cert type -1
    debug1: Local version string SSH-2.0-OpenSSH_8.0
    debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
    debug1: match: OpenSSH_7.4 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 it-prod-eu-phabricator.intramatch.eu:22 as 'git'
    debug3: hostkeys_foreach: reading file "/z/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /z/.ssh/known_hosts:1
    debug3: record_hostkey: found key type RSA in file /z/.ssh/known_hosts:6
    debug3: load_hostkeys: loaded 2 keys from it-prod-eu-phabricator.intramatch.eu
    debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,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,curve25519-sha256@libssh.org,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: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-ed25519-cert-v01@openssh.com,ssh-ed25519
    debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,aes256-cbc,aes192-cbc
    debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,aes256-cbc,aes192-cbc
    debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
    debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
    debug2: compression ctos: none,zlib@openssh.com,zlib
    debug2: compression stoc: none,zlib@openssh.com,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,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
    debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
    debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,blowfish-cbc,cast128-cbc,3des-cbc
    debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,blowfish-cbc,cast128-cbc,3des-cbc
    debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
    debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
    debug2: compression ctos: none,zlib@openssh.com
    debug2: compression stoc: none,zlib@openssh.com
    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: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
    debug1: kex: client->server cipher: chacha20-poly1305@openssh.com 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:e7bCcT5AK4aglLfUFF3bjHF4EppPM4C5fNSYjKJHUAw
    debug3: hostkeys_foreach: reading file "/z/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /z/.ssh/known_hosts:1
    debug3: record_hostkey: found key type RSA in file /z/.ssh/known_hosts:6
    debug3: load_hostkeys: loaded 2 keys from it-prod-eu-phabricator.intramatch.eu
    debug3: hostkeys_foreach: reading file "/z/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /z/.ssh/known_hosts:3
    debug3: load_hostkeys: loaded 1 keys from 172.23.80.12
    debug1: Host 'it-prod-eu-phabricator.intramatch.eu' is known and matches the ECDSA host key.
    debug1: Found key in /z/.ssh/known_hosts:1
    debug3: send packet: type 21
    debug2: set_newkeys: mode 1
    debug1: rekey out 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 in after 134217728 blocks
    debug1: Will attempt key: z:\\.ssh\\id_rsa_phabricator.key  explicit
    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 51
    debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
    debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic
    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: Trying private key: z:\\.ssh\\id_rsa_phabricator.key
    debug3: sign_and_send_pubkey: RSA SHA256:mKJVgcCsGSH2MLbfg3KcM5lB7IS3dgiFCXFX0/xD6B4
    debug3: sign_and_send_pubkey: signing using rsa-sha2-512
    debug3: send packet: type 50
    debug2: we sent a publickey packet, wait for reply
    debug3: receive packet: type 52
    debug1: Authentication succeeded (publickey).
    Authenticated to it-prod-eu-phabricator.intramatch.eu ([172.23.80.12]: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 no-more-sessions@openssh.com
    debug3: send packet: type 80
    debug1: Entering interactive session.
    debug1: pledge: network
    debug3: receive packet: type 80
    debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
    debug3: receive packet: type 4
    debug1: Remote: Forced command.
    debug3: receive packet: type 4
    debug1: Remote: Port forwarding disabled.
    debug3: receive packet: type 4
    debug1: Remote: X11 forwarding disabled.
    debug3: receive packet: type 4
    debug1: Remote: Agent forwarding disabled.
    debug3: receive packet: type 4
    debug1: Remote: PTY allocation disabled.
    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 0x20
    debug2: client_session2_setup: id 0
    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
    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
    debug2: channel 0: rcvd ext data 447
    debug3: receive packet: type 96
    debug2: channel 0: rcvd eof
    debug2: channel 0: output open -> drain
    debug2: channel 0: obuf_empty delayed efd 6/(447)
    phabricator-ssh-exec: Welcome to Phabricator.

    You are logged in as bmerlier.

    You have not specified a command to run. This means you are requesting an interactive shell, but Phabricator does not provide interactive shells over SSH.

    (Usually, you should run a command like "git clone" or "hg push" instead of connecting directly with SSH.)

    Supported commands are: conduit, git-lfs-authenticate, git-receive-pack, git-upload-pack, hg, svnserve.
    debug2: channel 0: written 447 to efd 6
    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 eow@openssh.com reply 0
    debug2: channel 0: rcvd eow
    debug2: channel 0: chan_shutdown_read (i0 o1 sock -1 wfd 4 efd 6 [write])
    debug2: channel 0: input open -> closed
    debug3: receive packet: type 97
    debug2: channel 0: rcvd 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 5 efd 6 [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/-1/6 sock -1 cc -1)

    debug3: send packet: type 1
    debug3: fd 1 is not O_NONBLOCK
    Transferred: sent 2416, received 3088 bytes, in 0.3 seconds
    Bytes per second: sent 8898.8, received 11374.0
    debug1: Exit status 1
  • ssh -T -vvvv new key pair:
    C:\Users\bmerlier>ssh.exe -T git@it-prod-eu-phabricator.intramatch.eu -i z:\.ssh\id_rsa_phabricator2.key -vvv
    OpenSSH_8.0p1, OpenSSL 1.1.1c  28 May 2019
    debug1: Reading configuration data /etc/ssh/ssh_config
    debug2: resolving "it-prod-eu-phabricator.intramatch.eu" port 22
    debug2: ssh_connect_direct
    debug1: Connecting to it-prod-eu-phabricator.intramatch.eu [172.23.80.12] port 22.
    debug1: Connection established.
    debug1: identity file z:\\.ssh\\id_rsa_phabricator2.key type -1
    debug1: identity file z:\\.ssh\\id_rsa_phabricator2.key-cert type -1
    debug1: Local version string SSH-2.0-OpenSSH_8.0
    debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
    debug1: match: OpenSSH_7.4 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 it-prod-eu-phabricator.intramatch.eu:22 as 'git'
    debug3: hostkeys_foreach: reading file "/z/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /z/.ssh/known_hosts:1
    debug3: record_hostkey: found key type RSA in file /z/.ssh/known_hosts:6
    debug3: load_hostkeys: loaded 2 keys from it-prod-eu-phabricator.intramatch.eu
    debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,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,curve25519-sha256@libssh.org,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: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-ed25519-cert-v01@openssh.com,ssh-ed25519
    debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,aes256-cbc,aes192-cbc
    debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,aes256-cbc,aes192-cbc
    debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
    debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
    debug2: compression ctos: none,zlib@openssh.com,zlib
    debug2: compression stoc: none,zlib@openssh.com,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,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
    debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
    debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,blowfish-cbc,cast128-cbc,3des-cbc
    debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,blowfish-cbc,cast128-cbc,3des-cbc
    debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
    debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
    debug2: compression ctos: none,zlib@openssh.com
    debug2: compression stoc: none,zlib@openssh.com
    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: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
    debug1: kex: client->server cipher: chacha20-poly1305@openssh.com 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:e7bCcT5AK4aglLfUFF3bjHF4EppPM4C5fNSYjKJHUAw
    debug3: hostkeys_foreach: reading file "/z/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /z/.ssh/known_hosts:1
    debug3: record_hostkey: found key type RSA in file /z/.ssh/known_hosts:6
    debug3: load_hostkeys: loaded 2 keys from it-prod-eu-phabricator.intramatch.eu
    debug3: hostkeys_foreach: reading file "/z/.ssh/known_hosts"
    debug3: record_hostkey: found key type ECDSA in file /z/.ssh/known_hosts:3
    debug3: load_hostkeys: loaded 1 keys from 172.23.80.12
    debug1: Host 'it-prod-eu-phabricator.intramatch.eu' is known and matches the ECDSA host key.
    debug1: Found key in /z/.ssh/known_hosts:1
    debug3: send packet: type 21
    debug2: set_newkeys: mode 1
    debug1: rekey out 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 in after 134217728 blocks
    debug1: Will attempt key: z:\\.ssh\\id_rsa_phabricator2.key  explicit
    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 51
    debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
    debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic
    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: Trying private key: z:\\.ssh\\id_rsa_phabricator2.key
    debug3: sign_and_send_pubkey: RSA SHA256:QunN0HhN7ruaF46AbKl/2R8PmbQx7Bj8XuOG8rTNy4I
    debug3: sign_and_send_pubkey: signing using rsa-sha2-512
    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,gssapi-keyex,gssapi-with-mic
    debug2: we did not send a packet, disable method
    debug1: No more authentication methods to try.
    git@it-prod-eu-phabricator.intramatch.eu: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).

phabricator version:
commit 2b8bbae5fb276b8ec7c26f6a82335eba680e8357 (phabricator/master)
Author: epriestley git@epriestley.com
Date: Fri Oct 16 14:01:55 2020 -0700
Arcanist version:
commit d41fb709abfacc81ba4356a65dc7d04f6c953f91
Author: epriestley git@epriestley.com
Date: Fri Oct 16 12:30:45 2020 -0700

Serveur:

  • Centos 7.7
  • PHP 7.3 form scl

Update :

  • There are some bad news. It seems that all key generate since May have stopped working
  • Rollback from php7.3.11 to php7.2.24 fixed issue. The problem come from php version but why ? I don’t know
  • Our test envrionement in php 7.3.11, work correctly … I become crazy

How many keys does your install have? (Run this command to figure it out.)

phabricator/ $ ./bin/ssh-auth | wc -l

If it’s a fairly large number (e.g., several hundred), this is probably because of a bug in some versions of OpenSSH. See https://secure.phabricator.com/T11827.

If you’re affected by this issue, updating sshd may fix it. However, the easiest workaround is to update your SSHD config for Phabricator and change this line:

- AuthorizedKeysCommand /usr/libexec/phabricator-ssh-hook.sh
+ AuthorizedKeysCommand /usr/libexec/phabricator-ssh-hook.sh %u --sshd-key %k

We have 179 installed keys.

[phd-user@plam0075 phabricator]$ ./bin/ssh-auth | wc -l
179

I will try to reproduce on our test environnement by install lots of keys and update sshd config.
It’s a little bit strange that this bug appear with php7.3 and back to normal when we rollboack on 7.2

Thanks