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公開鍵/秘密鍵でのssh認証の失敗

Gitlabで継続的デプロイパイプラインを設定しています。残念ながら、パイプラインからターゲットサーバーにSSHで接続しようとすると、認証は失敗します。

問題はUNIXに関連していて、gitlabではないと確信しているので、ここで質問します。

設定は次のとおりです。

  • Ssh-keygenを使用して、キーペアを作成しました。
  • サーバーの〜/ .ssh/authorized_keysに公開鍵を追加しました。
  • 秘密鍵は、クライアントサーバーの環境変数「SSH_PRIVATE_KEY」にエクスポートされます。
  • サーバーの権限：〜/ .ssh 700、〜/ .ssh/authorized_keys 600
  • サーバー上のsshd構成はすべてデフォルトです。

コミット時に、gitlabはdocker executor（docker image node：11.2）を起動します。次に、これらのコマンドはコンテナ内で実行されます。

'which ssh-agent || ( apt-get update -y && apt-get install openssh-client -y )'
eval $(ssh-agent -s)

    ##
    ## Add the SSH key stored in SSH_PRIVATE_KEY variable to the agent store
    ## We're using tr to fix line endings which makes ed25519 keys work
    ## without extra base64 encoding.
    ## https://gitlab.com/gitlab-examples/ssh-private-key/issues/1#note_48526556
    ##
echo "$SSH_PRIVATE_KEY" | tr -d '\r' | ssh-add - > /dev/null

mkdir -p ~/.ssh
chmod 700 ~/.ssh

echo "$SSH_PRIVATE_KEY" > ~/.ssh/known_hosts
chmod 644 ~/.ssh/known_hosts
ssh -vvv user@server

ここの指示に従いました： https://docs.gitlab.com/ce/ci/ssh_keys/

これが私の実行の出力です：

Running with gitlab-runner 11.5.0 (3afdaba6)
  on Runner2 7eb17b67
Using Docker executor with image node:11.2 ...
Pulling docker image node:11.2 ...
Using docker image sha256:e9737a5f718d8364a4bde8d82751bf0d2bace3d1b6492f6c16f1526b6e73cfa4 for node:11.2 ...
Running on runner-7eb17b67-project-40-concurrent-0 via server...
Fetching changes...
Removing node_modules/
HEAD is now at aa4a605 removing bugged command line
Checking out aa4a6054 as integrate_cd...
Skipping Git submodules setup
Checking cache for default...
No URL provided, cache will be not downloaded from shared cache server. Instead a local version of cache will be extracted. 
Successfully extracted cache
$ which ssh-agent || ( apt-get update -y && apt-get install openssh-client -y )
/usr/bin/ssh-agent
$ eval $(ssh-agent -s)
Agent pid 14
$ echo "$SSH_PRIV_KEY" | ssh-add - > /dev/null
Identity added: (stdin) ((stdin))
$ mkdir -p ~/.ssh
$ chmod 700 ~/.ssh
$ echo "$SSH_KNOWNHOST_KEY" > ~/.ssh/known_hosts
$ chmod 644 ~/.ssh/known_hosts
$ ssh -p 5555 -vvv user@server
OpenSSH_7.4p1 Debian-10+deb9u4, OpenSSL 1.0.2l  25 May 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
Pseudo-terminal will not be allocated because stdin is not a terminal.
debug2: resolving "server" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to servee[x.x.x.x] port 22
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.4p1 Debian-10+deb9u4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2
debug1: match: OpenSSH_7.2 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to server:22 as 'user'
debug3: put_Host_port: [server]:22
debug3: hostkeys_foreach: reading file "/root/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /root/.ssh/known_hosts:2
debug3: record_hostkey: found key type ECDSA in file /root/.ssh/known_hosts:4
debug3: record_hostkey: found key type ED25519 in file /root/.ssh/known_hosts:6
debug3: load_hostkeys: loaded 3 keys from [server]:22
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
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,[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,ext-info-c
debug2: Host key algorithms: [email protected],[email protected],[email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected],zlib
debug2: compression stoc: none,[email protected],zlib
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1
debug2: Host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ssh-dss,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug1: kex: algorithm: [email protected]
debug1: kex: Host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] 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 SHA256:1MfReEPXf/ResuMnmG/nEgimB5TxF1AcA2j4LBHBbTU
debug3: put_Host_port: [x.x.x.x]:22
debug3: put_Host_port: [server]:22
debug3: hostkeys_foreach: reading file "/root/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /root/.ssh/known_hosts:2
debug3: record_hostkey: found key type ECDSA in file /root/.ssh/known_hosts:4
debug3: record_hostkey: found key type ED25519 in file /root/.ssh/known_hosts:6
debug3: load_hostkeys: loaded 3 keys from [server]:22
debug3: hostkeys_foreach: reading file "/root/.ssh/known_hosts"
debug1: Host '[server]:22' is known and matches the ECDSA Host key.
debug1: Found key in /root/.ssh/known_hosts:4
Warning: Permanently added the ECDSA Host key for IP address '[x.x.x.x]:22' to the list of known hosts.
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey 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 after 134217728 blocks
debug2: key: (stdin) (0x55ff2d56d630), agent
debug2: key: /root/.ssh/id_rsa ((nil))
debug2: key: /root/.ssh/id_dsa ((nil))
debug2: key: /root/.ssh/id_ecdsa ((nil))
debug2: key: /root/.ssh/id_ed25519 ((nil))
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,keyboard-interactive
debug3: start over, passed a different list publickey,keyboard-interactive
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: (stdin)
debug3: send_pubkey_test
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Trying private key: /root/.ssh/id_rsa
debug3: no such identity: /root/.ssh/id_rsa: No such file or directory
debug1: Trying private key: /root/.ssh/id_dsa
debug3: no such identity: /root/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /root/.ssh/id_ecdsa
debug3: no such identity: /root/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /root/.ssh/id_ed25519
debug3: no such identity: /root/.ssh/id_ed25519: No such file or directory
debug2: we did not send a packet, disable method
debug3: authmethod_lookup keyboard-interactive
debug3: remaining preferred: password
debug3: authmethod_is_enabled keyboard-interactive
debug1: Next authentication method: keyboard-interactive
debug2: userauth_kbdint
debug3: send packet: type 50
debug2: we sent a keyboard-interactive packet, wait for reply
debug3: receive packet: type 60
debug2: input_userauth_info_req
debug2: input_userauth_info_req: num_prompts 1
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug3: send packet: type 61
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,keyboard-interactive
debug2: userauth_kbdint
debug3: send packet: type 50
debug2: we sent a keyboard-interactive packet, wait for reply
debug3: receive packet: type 60
debug2: input_userauth_info_req
debug2: input_userauth_info_req: num_prompts 1
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug3: send packet: type 61
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,keyboard-interactive
debug2: userauth_kbdint
debug3: send packet: type 50
debug2: we sent a keyboard-interactive packet, wait for reply
debug3: receive packet: type 60
debug2: input_userauth_info_req
debug2: input_userauth_info_req: num_prompts 1
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug3: send packet: type 61
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,keyboard-interactive
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey,keyboard-interactive).
ERROR: Job failed: exit code 1

私はsshの興味深い部分はこれだと思います：

debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: (stdin)
debug3: send_pubkey_test
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Trying private key: /root/.ssh/id_rsa
debug3: no such identity: /root/.ssh/id_rsa: No such file or directory
debug1: Trying private key: /root/.ssh/id_dsa
debug3: no such identity: /root/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /root/.ssh/id_ecdsa
debug3: no such identity: /root/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /root/.ssh/id_ed25519
debug3: no such identity: /root/.ssh/id_ed25519: No such file or directory
debug2: we did not send a packet, disable method
debug3: authmethod_lookup keyboard-interactive
debug3: remaining preferred: password

認証を試みます

debug2：公開鍵パケットを送信しました。応答を待ちます

しかし、直後にSSH_MSG_USERAUTH_FAILUREで失敗しました

debug3：パケットの受信：タイプ51

次に、ランナーに存在しないいくつかの公開鍵を試します。

何が起こっているのですか？ SSH_MSG_USERAUTH_FAILUREの原因は何ですか？

ありがとうございました。

sshopensshssh-keysgitlab
2
Jean-Francois

答えが見つかりました。接続しようとしたサーバーからもログを取得しました。

sshd [40354]：認証が拒否されました：ディレクトリ/ webの所有権またはモードが正しくありません

ユーザーは自分のホームリポジトリにあるはずのより多くの権限を持っていたことがわかりました。 drwxr-xr-xに修正して問題を解決しました。

したがって、sshは次のモードを検証しているようです

  • .ssh /
  • .ssh/authorized_keys
  • ユーザーのHOMEリポジトリ
1
Jean-Francois