--- title: "BASH : Comment débugger un problème SSH côté serveur ?" canonical: "https://blog.kaptus.net/space/BKAP/blog/166395907/BASH%20%3A%20Comment%20d%C3%A9bugger%20un%20probl%C3%A8me%20SSH%20c%C3%B4t%C3%A9%20serveur%20%3F" format: markdown --- ## Problème Comment débugger un problème de connexion ssh côté serveur ? ## Solution Il suffit de lancer le serveur sshd en mode débug sur un port spécifique : ```shell /usr/sbin/sshd -p 2222 -d ``` > ✅ debug1: sshd version OpenSSH_7.9, OpenSSL 1.1.1d 10 Sep 2019 > ✅ debug1: private host key #0: ssh-rsa SHA256:0tyjYDs+qXFLy0xES3WrN9VsMXndrLeDGyQlRSclvbQ > ✅ debug1: private host key #1: ecdsa-sha2-nistp256 SHA256:pAte8iSmv8/XjpWlaEQ/ZcqeU9K5p8bEDtvYlpWYTZw > ✅ debug1: private host key #2: ssh-ed25519 SHA256:1k9ccp+epCjD0lb8UKubSjWp5BiXWkdRBitGs3Qz8Lo > ✅ debug1: rexec_argv[0]='/usr/sbin/sshd' > ✅ debug1: rexec_argv[1]='-p' > ✅ debug1: rexec_argv[2]='2222' > ✅ debug1: rexec_argv[3]='-d' > ✅ debug1: Set /proc/self/oom_score_adj from 0 to -1000 > ✅ debug1: Bind to port 2222 on 0.0.0.0. > ✅ Server listening on 0.0.0.0 port 2222. > ✅ debug1: Bind to port 2222 on ::. > ✅ Server listening on :: port 2222. > ✅ debug1: Server will not fork when running in debugging mode. > ✅ debug1: rexec start in 5 out 5 newsock 5 pipe -1 sock 8 > ✅ debug1: inetd sockets after dupping: 3, 3 > ✅ Connection from 77.140.85.93 port 61777 on 212.129.31.20 port 2222 > ✅ debug1: Client protocol version 2.0; client software version OpenSSH_7.8 > ✅ debug1: match: OpenSSH_7.8 pat OpenSSH* compat 0x04000000 > ✅ debug1: Local version string SSH-2.0-OpenSSH_7.9p1 Debian-10+deb10u1 > ✅ debug1: permanently_set_uid: 106/65534 [preauth] > ✅ debug1: list_hostkey_types: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519 [preauth] > ✅ debug1: SSH2_MSG_KEXINIT sent [preauth] > ✅ debug1: SSH2_MSG_KEXINIT received [preauth] > ✅ debug1: kex: algorithm: curve25519-sha256 [preauth] > ✅ debug1: kex: host key algorithm: ecdsa-sha2-nistp256 [preauth] > ✅ debug1: kex: client->server cipher: [chacha20-poly1305@openssh.com](mailto:chacha20-poly1305@openssh.com) MAC: compression: none [preauth] > ✅ debug1: kex: server->client cipher: [chacha20-poly1305@openssh.com](mailto:chacha20-poly1305@openssh.com) MAC: compression: none [preauth] > ✅ debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth] > ✅ debug1: rekey after 134217728 blocks [preauth] > ✅ debug1: SSH2_MSG_NEWKEYS sent [preauth] > ✅ debug1: expecting SSH2_MSG_NEWKEYS [preauth] > ✅ debug1: SSH2_MSG_NEWKEYS received [preauth] > ✅ debug1: rekey after 134217728 blocks [preauth] > ✅ debug1: KEX done [preauth] > ✅ debug1: userauth-request for user prevoir service ssh-connection method none [preauth] > ✅ debug1: attempt 0 failures 0 [preauth] > ✅ debug1: user prevoir matched group list sftponly at line 136 > ✅ debug1: PAM: initializing for "prevoir" > ✅ debug1: PAM: setting PAM_RHOST to "77.140.85.93" > ✅ debug1: PAM: setting PAM_TTY to "ssh" > ✅ debug1: userauth-request for user prevoir service ssh-connection method publickey [preauth] > ✅ debug1: attempt 1 failures 0 [preauth] > ✅ debug1: userauth_pubkey: test pkalg rsa-sha2-512 pkblob RSA SHA256:mL0EBxk5nsvTSQRe1lR8BEuZEv7wGSPpLPhBJF5w4IE [preauth] > ✅ debug1: temporarily_use_uid: 1005/1005 (e=0/0) > ✅ debug1: trying public key file /opt/naos/users/prevoir/.ssh/authorized_keys > ✅ debug1: Could not open authorized keys '/opt/naos/users/prevoir/.ssh/authorized_keys': No such file or directory > ✅ debug1: restore_uid: 0/0 > ✅ debug1: temporarily_use_uid: 1005/1005 (e=0/0) > ✅ debug1: trying public key file /opt/naos/users/prevoir/.ssh/authorized_keys2 > ✅ debug1: Could not open authorized keys '/opt/naos/users/prevoir/.ssh/authorized_keys2': No such file or directory > ✅ debug1: restore_uid: 0/0 > ✅ Failed publickey for prevoir from 77.140.85.93 port 61777 ssh2: RSA SHA256:mL0EBxk5nsvTSQRe1lR8BEuZEv7wGSPpLPhBJF5w4IE > ✅ debug1: userauth-request for user prevoir service ssh-connection method publickey [preauth] > ✅ debug1: attempt 2 failures 1 [preauth] > ✅ debug1: userauth_pubkey: test pkalg ssh-ed25519 pkblob ED25519 SHA256:0p6glDFVNMo5pF4wnMAOcdF0gdIGjTWIgNu6rusBSMU [preauth] > ✅ debug1: temporarily_use_uid: 1005/1005 (e=0/0) > ✅ debug1: trying public key file /opt/naos/users/prevoir/.ssh/authorized_keys > ✅ debug1: Could not open authorized keys '/opt/naos/users/prevoir/.ssh/authorized_keys': No such file or directory > ✅ debug1: restore_uid: 0/0 > ✅ debug1: temporarily_use_uid: 1005/1005 (e=0/0) > ✅ debug1: trying public key file /opt/naos/users/prevoir/.ssh/authorized_keys2 > ✅ debug1: Could not open authorized keys '/opt/naos/users/prevoir/.ssh/authorized_keys2': No such file or directory > ✅ debug1: restore_uid: 0/0 > ✅ Failed publickey for prevoir from 77.140.85.93 port 61777 ssh2: ED25519 SHA256:0p6glDFVNMo5pF4wnMAOcdF0gdIGjTWIgNu6rusBSMU > ✅ debug1: userauth-request for user prevoir service ssh-connection method password [preauth] > ✅ debug1: attempt 3 failures 2 [preauth] > ✅ debug1: PAM: password authentication accepted for prevoir > ✅ debug1: do_pam_account: called > ✅ Accepted password for prevoir from 77.140.85.93 port 61777 ssh2 > ✅ debug1: monitor_child_preauth: prevoir has been authenticated by privileged process > ✅ debug1: monitor_read_log: child log fd closed > ✅ debug1: PAM: establishing credentials > ✅ User child is on pid 8074 > ✅ debug1: SELinux support disabled > ✅ debug1: PAM: establishing credentials > ✅ **bad ownership or modes for chroot directory component "/opt/naos/"** > ✅ debug1: do_cleanup > ✅ debug1: do_cleanup > ✅ debug1: PAM: cleanup > ✅ debug1: PAM: closing session > ✅ debug1: PAM: deleting credentials > ✅ debug1: audit_event: unhandled event 12 ## Articles connexes > Macro (contentbylabel)