SFTP access by SSH on port 9122 doesn't works

Hello,

I have created a SFTP access by SSH with an authentification by private key. For that connection I have to use the port 9122 but it doesn't works. When I want to connect, a winws asking SSH password open, I put into the passphrase of my private key put it fails.
Capture d’écran 2024-06-06 181500

All the parameters have been tested succefully with WinSCP but doesn't works with Opus. Any idea what's wrong ?

Thanks by advance for your help

Regards,

Yorik

What does the FTP log say?

The problem seems coming from the key that can't be loaded (I don't understand why and what "PuTTY key format too new" means). Does the private key has to be in a specific folder to be retrieved ?) :

Ouverture de connexion sftpgw.allianz.com:9122
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "ubyriskfr".
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "ubyriskfr".
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\sftp_allianz_key"
Unable to use this key file (OpenSSH SSH-2 private key (new format))
Unable to use key file "D:\Documents\Ubyrisk\Logiciels\sftp_allianz_key" (OpenSSH SSH-2 private key (new format))
Using username "EXT_R11521261".
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\sftp_allianz_key"
Unable to use this key file (OpenSSH SSH-2 private key (new format))
Unable to use key file "D:\Documents\Ubyrisk\Logiciels\sftp_allianz_key" (OpenSSH SSH-2 private key (new format))
Using username "EXT_R11521261".
Reading key file "D:\Documents\Ubyrisk\Logiciels\sftp_allianz_key"
Unable to use this key file (OpenSSH SSH-2 private key (new format))
Unable to use key file "D:\Documents\Ubyrisk\Logiciels\sftp_allianz_key" (OpenSSH SSH-2 private key (new format))
Using username "EXT_R11521261".
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Keyboard-interactive authentication failed
Access denied
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Keyboard-interactive authentication failed
Access denied
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Using username "EXT_R11521261".
Keyboard-interactive authentication failed
Access denied
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Keyboard-interactive authentication failed
Access denied
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Keyboard-interactive authentication failed
Access denied
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
Ouverture de connexion sftpgw.allianz.com:9122
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée
Ouverture de connexion sftpgw.allianz.com:9122
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
Ouverture de connexion sftpgw.allianz.com:9122
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server version: SSH-2.0-SFTP Server
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Host key fingerprint is:
ssh-rsa 2048 4a:87:3a:74:b7:f1:65:95:55:b5:75:8e:4a:40:2d:fc
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised zlib (RFC1950) compression
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Initialised zlib (RFC1950) decompression
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Reading key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "D:\Documents\Ubyrisk\Logiciels\private_key_sftp_allianz_key.ppk" (PuTTY key format too new)
Using username "EXT_R11521261".
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connexion fermée

You can use PuttyGen to convert the key to the V2 format:

We hope to add support for the newer format in the future, as part of replacing the SFTP code in general with an improved version.

Thanks it works now !!!

Another question : is there a way to avoid to enter the pass-phrase at each connection ?

You can use Pageant (part of PuTTY) to load a key into memory, where you only have to enter the password the first time you load it (after a reboot).

It may also be possible to have keys without any password, but I'm not sure off the top of my head (and they'd obviously be usable to anyone who had access to the file then).