一般ユーザーで公開鍵認証ができない

Question

Conoha VPSのCentOS Stream 8 のVPSで、一般ユーザーでの公開鍵認証ができません。
一般ユーザーで公開鍵認証を使用してSSHログインするを参考にしましたが、Permission denied (publickey,gssapi-keyex,gssapi-with-mic)と出てしまいます。
ちなみに、vオプションのログはこのようになっておりました。

OpenSSH_for_Windows_8.1p1, LibreSSL 3.0.2
debug3: Failed to open file:C:/Users/fufl/.ssh/config error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_config error:2
debug2: resolve_canonicalize: hostname xxx.xx.xx.xxx is address
debug2: ssh_connect_direct
debug1: Connecting to xxx.xx.xx.xxx [xxx.xx.xx.xxx] port xx.
debug1: Connection established.
debug3: Failed to open file:C:/Users/fufl/.ssh/id_rsa.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_rsa type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_rsa-cert error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_rsa-cert.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_rsa-cert type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_dsa error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_dsa.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_dsa type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_dsa-cert error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_dsa-cert.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_dsa-cert type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_ecdsa error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_ecdsa.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_ecdsa type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_ecdsa-cert error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_ecdsa-cert.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_ecdsa-cert type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_ed25519 error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_ed25519.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_ed25519 type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_ed25519-cert error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_ed25519-cert.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_ed25519-cert type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_xmss error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_xmss.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_xmss type -1
debug3: Failed to open file:C:/Users/fufl/.ssh/id_xmss-cert error:2
debug3: Failed to open file:C:/Users/fufl/.ssh/id_xmss-cert.pub error:2
debug1: identity file C:\Users\fufl/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_for_Windows_8.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_8.0
debug1: match: OpenSSH_8.0 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to xxx.xx.xx.xxx:xx as 'fufl'
debug3: hostkeys_foreach: reading file "C:\Users\fufl/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file C:\Users\fufl/.ssh/known_hosts:2
debug3: load_hostkeys: loaded 1 keys from xxx.xx.xx.xxx
debug3: Failed to open file:C:/Users/fufl/.ssh/known_hosts2 error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_known_hosts error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_known_hosts2 error:2
debug3: order_hostkeyalgs: prefer hostkeyalgs: [e-mail],[e-mail],[e-mail],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[e-mail],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: [e-mail],[e-mail],[e-mail],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[e-mail],[e-mail],[e-mail],[e-mail],ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: [e-mail],aes128-ctr,aes192-ctr,aes256-ctr,[e-mail],[e-mail]
debug2: ciphers stoc: [e-mail],aes128-ctr,aes192-ctr,aes256-ctr,[e-mail],[e-mail]
debug2: MACs ctos: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[e-mail],zlib
debug2: compression stoc: none,[e-mail],zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[e-mail],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [e-mail],[e-mail],aes256-ctr,aes256-cbc,[e-mail],aes128-ctr,aes128-cbc
debug2: ciphers stoc: [e-mail],[e-mail],aes256-ctr,aes256-cbc,[e-mail],aes128-ctr,aes128-cbc
debug2: MACs ctos: [e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha1,[e-mail],hmac-sha2-512
debug2: MACs stoc: [e-mail],[e-mail],[e-mail],[e-mail],hmac-sha2-256,hmac-sha1,[e-mail],hmac-sha2-512
debug2: compression ctos: none,[e-mail]
debug2: compression stoc: none,[e-mail]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [e-mail] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [e-mail] MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:XX...
debug3: hostkeys_foreach: reading file "C:\Users\fufl/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file C:\Users\fufl/.ssh/known_hosts:2
debug3: load_hostkeys: loaded 1 keys from xxx.xx.xx.xxx
debug3: Failed to open file:C:/Users/fufl/.ssh/known_hosts2 error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_known_hosts error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_known_hosts2 error:2
debug1: Host 'xxx.xx.xx.xxx' is known and matches the ECDSA host key.
debug1: Found key in C:\Users\fufl/.ssh/known_hosts:2
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey in after 134217728 blocks

Windows10からログインしようとしています。

ちなみにSSH Keyを登録するの方ではログインまで行えました。

Comments

[yukky1201]

Windows側の鍵保存ディレクトリは下記ですがちゃんと存在していますか

C:/Users/fufl/.ssh/

[pice]

ありがとうございます。存在しています。

Answer 1

まずは下記を確認してみてはどうでしょうか？
それでも、解決しなければ、その確認結果を質問に追記するとさらに回答が集まりやすいかと思います。

可能性
・鍵やディレクトリのアクセス権が間違っている
・鍵のペアが間違っている

確認点
・サーバ側のログに何が出ているか
・サーバ側に置いたファイルの権限が適切か
・クライアント側の秘密鍵の権限が適切か

参考
https://teratail.com/questions/16932
https://qiita.com/youcune/items/2f427979403771f2e03a

また、質問文にデバッグ表示だけでなく、エラーが出たときに実行したコマンドとエラーの表示も記載すると分かりやすいですね。
お試しの環境では、sshコマンドを使ったと思いますが、どんなオプション付きで実行したか分かりません。

Comments

[pice]

ありがとうございました。結果的に何が悪いか特定には至りませんでしたが、サーバー側でssh-keygen -m pemとして鍵を作成し、秘密鍵をクライアント側でTeratermから貼り付けして、サーバー側のディレクトリ、ファイルを適切な権限にすることで認証させることができるようになりました。細かく確認点等教えて頂きありがとうございました。

[pice]

以下の記事を参考にさせて頂きました。
https://qiita.com/YuuT_38/items/6b27cba9dc943f53ab30

https://www.server-world.info/query?os=CentOS_8&p=ssh&f=4