Si KexAlgorithms
n'est pas configuré explicitement dans un fichier de configuration ssh, quel est l'algorithme d'échange de clé par défaut que Opensh peut utiliser?
La version openssh que j'utilise est OpenSSH_6.4p1.
Après vérification, cette information peut être obtenue de deux manières.
lire la page de manuel pour sshd_config(5)
KexAlgorithms
Specifies the available KEX (Key Exchange) algorithms.
Multiple algorithms must be comma-separated.
The default is
ecdh-sha2-nistp256 ,
ecdh-sha2-nistp384 ,
ecdh-sha2-nistp521 ,
diffie-hellman-group-exchange-sha256 ,
diffie-hellman-group-exchange-sha1 ,
diffie-hellman-group14-sha1 ,
diffie-hellman-group1-sha1 .
read from ssh -vvv
logs (La première partie correspond au kexalgorithm,hmac,ciphers
pris en charge du côté client; la deuxième partie correspond au serveur sshd.)
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,aes192-cbc,aes256-cbc,arcfour256,arcfour128,3des-cbc,blowfish-cbc,cast128-cbc,arcfour
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,aes192-cbc,aes256-cbc,arcfour256,arcfour128,3des-cbc,blowfish-cbc,cast128-cbc,arcfour
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,hmac-sha1-96,hmac-md5-96,hmac-sha2-256,hmac-sha2-512
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,hmac-sha1-96,hmac-md5-96,hmac-sha2-256,hmac-sha2-512
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit: none,[email protected]
requête ssh
pour les algorithmes pris en charge: ssh -Q kex server
(majuscule -Q)
diffie-hellman-group1-sha1
diffie-hellman-group14-sha1
diffie-hellman-group-exchange-sha1
diffie-hellman-group-exchange-sha256
ecdh-sha2-nistp256
ecdh-sha2-nistp384
ecdh-sha2-nistp521
diffie-hellman-group1-sha1
[email protected]
ssh -G 192.168.1.2
montre la configuration qui inclut kexalgorithms . Par exemple,
kexalgorithms 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-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1
Si vous voulez configurer uniquement diffie-hellman-group1-sha1 pour kexalgorithms,
ssh -oKexAlgorithms=diffie-hellman-group1-sha1 [email protected]