# ssh n'utilise pas mes clés privées et publiques

**URL:** https://community.ovhcloud.com/t/ssh-nutilise-pas-mes-cles-privees-et-publiques/53886
**Category:** Bare Metal et VPS
**Tags:** vps
**Created:** [Septembre 9, 2026, 7:27 UTC](https://community.ovhcloud.com/t/ssh-nutilise-pas-mes-cles-privees-et-publiques/53886 "2026-09-09T07:27:17Z")
**Posts on this page:** 5
**Page:** 1

<div class="post-metadata">

### Author: ![MartinR2](https://community.ovhcloud.com/letter_avatar/martinr2/32/5_5575768a8748004e209b776fc1b2916d.png) [@MartinR2](https://community.ovhcloud.com/u/MartinR2)
#### Post date: [Septembre 9, 2026, 7:27 UTC](https://community.ovhcloud.com/t/ssh-nutilise-pas-mes-cles-privees-et-publiques/53886/1 "2026-09-09T07:27:17Z")

</div>

Bonjour

Je souhaite accéder depuis un serveur Kimsuffi Ubuntu 24.04 à un autre serveur cible Debian, en ssh avec des clés publiques et privées, afin de copier des fichiers de l'un vers l'autre.

J'ai généré la paire de clés sur le client et copié la clé publique sur le serveur cible comme d'habitude.

Cela fonctionne bien, mais une seule fois. Au bout d'un moment, un mot de passe est demandé parce qu'apparemment l'authentification par clé ne marche plus. Pour l'instant j'ai autorisé cette identification par mot de passe, mais je souhaite évidemment l'interdire.

Voici une sortie avec

ssh -v monuser@nas

OpenSSH\_9.6p1 Ubuntu-3ubuntu13.19, OpenSSL 3.0.13 30 Jan 2024  
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 \*  
debug1: Connecting to nas [192.168.27.70] port 22.  
debug1: Connection established.  
debug1: identity file /home/monuser/.ssh/id\_rsa type -1  
debug1: identity file /home/monuser/.ssh/id\_rsa-cert type -1  
debug1: identity file /home/monuser/.ssh/id\_ecdsa type -1  
debug1: identity file /home/monuser/.ssh/id\_ecdsa-cert type -1  
debug1: identity file /home/monuser/.ssh/id\_ecdsa\_sk type -1  
debug1: identity file /home/monuser/.ssh/id\_ecdsa\_sk-cert type -1  
debug1: identity file /home/monuser/.ssh/id\_ed25519 type -1  
debug1: identity file /home/monuser/.ssh/id\_ed25519-cert type -1  
debug1: identity file /home/monuser/.ssh/id\_ed25519\_sk type -1  
debug1: identity file /home/monuser/.ssh/id\_ed25519\_sk-cert type -1  
debug1: identity file /home/monuser/.ssh/id\_xmss type -1  
debug1: identity file /home/monuser/.ssh/id\_xmss-cert type -1  
debug1: identity file /home/monuser/.ssh/id\_dsa type -1  
debug1: identity file /home/monuser/.ssh/id\_dsa-cert type -1  
debug1: Local version string SSH-2.0-OpenSSH\_9.6p1 Ubuntu-3ubuntu13.19  
debug1: Remote protocol version 2.0, remote software version OpenSSH\_9.2p1 Debian-2+deb12u6  
debug1: compat\_banner: match: OpenSSH\_9.2p1 Debian-2+deb12u6 pat OpenSSH_ compat 0x04000000  
debug1: Authenticating to nas:22 as 'monuser'  
debug1: load\_hostkeys: fopen /home/monuser/.ssh/known\_hosts2: No such file or directory  
debug1: load\_hostkeys: fopen /etc/ssh/ssh\_known\_hosts: No such file or directory  
debug1: load\_hostkeys: fopen /etc/ssh/ssh\_known\_hosts2: No such file or directory  
debug1: SSH2\_MSG\_KEXINIT sent  
debug1: SSH2\_MSG\_KEXINIT received  
debug1: kex: algorithm: curve25519-sha256  
debug1: kex: host key algorithm: ssh-ed25519  
debug1: kex: server-\>client cipher: [chacha20-poly1305@openssh.com](mailto:chacha20-poly1305@openssh.com) MAC: compression: none  
debug1: kex: client-\>server cipher: [chacha20-poly1305@openssh.com](mailto:chacha20-poly1305@openssh.com) MAC: compression: none  
debug1: expecting SSH2\_MSG\_KEX\_ECDH\_REPLY  
debug1: SSH2\_MSG\_KEX\_ECDH\_REPLY received  
debug1: Server host key: ssh-ed25519 SHA256:tF85nkKWqKg0GoHiZMOEM0DS/TO1m0kVQ92+KMiKp1M  
debug1: load\_hostkeys: fopen /home/monuser/.ssh/known\_hosts2: No such file or directory  
debug1: load\_hostkeys: fopen /etc/ssh/ssh\_known\_hosts: No such file or directory  
debug1: load\_hostkeys: fopen /etc/ssh/ssh\_known\_hosts2: No such file or directory  
debug1: Host 'nas' is known and matches the ED25519 host key.  
debug1: Found key in /home/monuser/.ssh/known\_hosts:5  
debug1: ssh\_packet\_send2\_wrapped: resetting send seqnr 3  
debug1: rekey out after 134217728 blocks  
debug1: SSH2\_MSG\_NEWKEYS sent  
debug1: expecting SSH2\_MSG\_NEWKEYS  
debug1: ssh\_packet\_read\_poll2: resetting read seqnr 3  
debug1: SSH2\_MSG\_NEWKEYS received  
debug1: rekey in after 134217728 blocks  
debug1: SSH2\_MSG\_EXT\_INFO received  
debug1: kex\_ext\_info\_client\_parse: server-sig-algs=\<[ssh-ed25519,sk-ssh-ed25519@openssh.com](mailto:ssh-ed25519,sk-ssh-ed25519@openssh.com),ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,sk-ecdsa-sha2-nistp256@openssh.com,webauthn-sk-ecdsa-sha2-nistp256@openssh.com,ssh-dss,ssh-rsa,rsa-sha2-256,rsa-sha2-512\>  
debug1: kex\_ext\_info\_check\_ver: publickey-hostbound@openssh.com=\<0\>  
debug1: SSH2\_MSG\_SERVICE\_ACCEPT received  
debug1: Authentications that can continue: publickey,password  
debug1: Next authentication method: publickey  
debug1: Will attempt key: /home/monuser/.ssh/id\_rsa  
debug1: Will attempt key: /home/monuser/.ssh/id\_ecdsa  
debug1: Will attempt key: /home/monuser/.ssh/id\_ecdsa\_sk  
debug1: Will attempt key: /home/monuser/.ssh/id\_ed25519  
debug1: Will attempt key: /home/monuser/.ssh/id\_ed25519\_sk  
debug1: Will attempt key: /home/monuser/.ssh/id\_xmss  
debug1: Will attempt key: /home/monuser/.ssh/id\_dsa  
debug1: Trying private key: /home/monuser/.ssh/id\_rsa  
debug1: Trying private key: /home/monuser/.ssh/id\_ecdsa  
debug1: Trying private key: /home/monuser/.ssh/id\_ecdsa\_sk  
debug1: Trying private key: /home/monuser/.ssh/id\_ed25519  
debug1: Trying private key: /home/monuser/.ssh/id\_ed25519\_sk  
debug1: Trying private key: /home/monuser/.ssh/id\_xmss  
debug1: Trying private key: /home/monuser/.ssh/id\_dsa  
debug1: Next authentication method: password  
monuser@nas's password:

J'ai vérifié que la clé publique reste bien présente sur le serveur cible sur une ligne du fichier .ssh/authorized\_keys et que la clé privée est toujours dans mon dossier .ssh

Je ne comprends pas pourquoi il essaie la clé privée /home/monuser/.ssh/id\_rsa et les 6 suivantes, alors que ces fichiers n'existent pas. Ils existent dans /etc/ssh pour l'user root, mais pas dans /home/monuser/.ssh. La clé que j'ai généré a un autre nom, mais n'est pas essayée.

Auriez-vous une idée de ce qui peut se passer, ou de ce que je peux vérifier ?

Merci.

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<div class="post-metadata">

### Author: ![le\_sbraz](https://community.ovhcloud.com/user_avatar/community.ovhcloud.com/le_sbraz/32/45_2.png) [@le\_sbraz](https://community.ovhcloud.com/u/le_sbraz)
#### Post date: [Septembre 9, 2026, 9:28 UTC](https://community.ovhcloud.com/t/ssh-nutilise-pas-mes-cles-privees-et-publiques/53886/2 "2026-09-09T09:28:07Z")

</div>

Bonjour, vous pouvez jeter un œil aux logs côté serveur avec `journalctl -u ssh.service`. Si ça ne donne pas assez d'information, vous pouvez ajouiter `LogLevel VERBOSE` à `sshd_config`.

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<div class="post-metadata">

### Author: ![MartinR2](https://community.ovhcloud.com/letter_avatar/martinr2/32/5_5575768a8748004e209b776fc1b2916d.png) [@MartinR2](https://community.ovhcloud.com/u/MartinR2)
#### Post date: [Septembre 9, 2026, 10:52 UTC](https://community.ovhcloud.com/t/ssh-nutilise-pas-mes-cles-privees-et-publiques/53886/3 "2026-09-09T10:52:41Z")

</div>

`journalctl -u ssh.service` (sans ajouter `LogLevel VERBOSE`) me retourne :

`sept. 09 12:41:33 NAS sshd[8680]: Received signal 15; terminating.`  
`sept. 09 12:41:33 NAS sshd[2089338]: Server listening on 0.0.0.0 port 22.`  
`sept. 09 12:41:33 NAS sshd[2089338]: Server listening on :: port 22.`  
`sept. 09 12:41:42 NAS sshd[2089351]: Connection closed by authenticating user monuser 192.168.27.71 port 38296 [preauth]`

Qu'est-ce que cela signifie ? Pourquoi mon serveur OVH envoie-t-il un `signal 15` ?  
Pour rappel je me connecte bien depuis d'autres clients laptops Ubuntu et sur le serveur on a :

`sept. 09 12:47:18 NAS sshd[2089833]: Accepted publickey for monuser from 192.168.27.75 port 57576 ssh2: ED25519 SHA256:RcCaZ3DzHMG7mIQ9XemijsSPsucdCBnt5v7RRETi2KA`  
`sept. 09 12:47:18 NAS sshd[2089833]: pam_unix(sshd:session): session opened for user monuser(uid=1000) by (uid=0)`

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<div class="post-metadata">

### Author: ![MartinR2](https://community.ovhcloud.com/letter_avatar/martinr2/32/5_5575768a8748004e209b776fc1b2916d.png) [@MartinR2](https://community.ovhcloud.com/u/MartinR2)
#### Post date: [Septembre 9, 2026, 1:49 UTC](https://community.ovhcloud.com/t/ssh-nutilise-pas-mes-cles-privees-et-publiques/53886/4 "2026-09-09T13:49:35Z")

</div>

Cela fonctionne en indiquant la clé privée à utiliser, avec le paramètre -i

`ssh -i .ssh/mon_certificat monuser@serveur`

Pourquoi est-ce nécessaire sur ce serveur KimSuffi et pas sur d'autres machines Ubuntu, ça je l'ignore...

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<div class="post-metadata">

### Author: ![system](https://community.ovhcloud.com/user_avatar/community.ovhcloud.com/system/32/5_2.png) [@system](https://community.ovhcloud.com/u/system)
#### Post date: [Septembre 11, 2026, 1:49 UTC](https://community.ovhcloud.com/t/ssh-nutilise-pas-mes-cles-privees-et-publiques/53886/5 "2026-09-11T13:49:52Z")

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