ubuntu 22，openssh server 升级了
putty登录，提示错误：server refused our key
/var/log/auth.log: userauth_pubkey: key type ssh-rsa not in PubkeyAcceptedAlgorithms [preauth]
解决办法：
vi /etc/ssh/sshd_config，加入
PubkeyAuthentication yes
PubkeyAcceptedAlgorithms +ssh-rsa
KexAlgorithms
curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
HostKeyAlgorithms=+ssh-rsa,ssh-dss
再 systemctl restart sshd
就可以用putty登录
puttygen.exe
"file>Load Private key",选择 2023.ppk，再“save public key”保存为2023.pub，再“Conversions>Export OpenSSH key”保存为2023.pem
secureCRT，2023.pem 为 “SSH2 > Authentication > PublicKey > Properties > Use identity or certificate file”
就可以用secureCRT登录
The ssh-rsa signature scheme uses SHA-1 and it's sensible to chosen-prefix attacks.
If you can't upgrade the server, you can create new keys using ed25519, or ecdsa.
ssh-keygen -t ecdsa -a 64 -b 384
或者 用 puttygen.exe 最下方 不选择 RSA 而是选择 ECDSA
参考：
https://dev.to/cloudx/why-openssh-8-8-cannot-find-a-host-key-type-if-ssh-rsa-is-provided-49i
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本帖最后由 linda 于 2022-12-23 17:41 编辑 ]
