第 3 部分:SSH Daemon

知道目標的地址後,即可驗證 SSH 連線。您可以嘗試使用

ssh -i ~/.ssh/fuchsia_ed25519 fe80::ca63:14ff:fe70:51db%zx-c863147051da

這會連線並嘗試使用位於 ~/.ssh/fuchsia_ed25519 的 SSH 私密金鑰進行驗證。如果連線失敗,請將 -v 標記傳遞至 ssh,以取得更詳細的診斷資訊:

ssh -v -i ~/.ssh/fuchsia_ed25519 fe80::ca63:14ff:fe70:51db%zx-c863147051da

系統會產生大量輸出內容。在查看失敗情形之前,建議先瞭解成功連線的條件。以下是主要注意事項:

bash$ ssh -v -i ~/.ssh/fuchsia_ed25519 fe80::ca63:14ff:fe70:51db%zx-c863147051da
...
debug1: Connecting to fe80::ca63:14ff:fe70:51db%zx-c863147051da [fe80::ca63:14ff:fe70:51db%zx-c863147051da] port 22.
debug1: using TCP window size of 4194304 / 4194304
debug1: fd 3 clearing O_NONBLOCK
debug1: Connection established.
...
debug1: Offering public key: /home/user/.ssh/fuchsia_ed25519 ED25519 SHA256:<snip>
debug1: Server accepts key: /home/user/.ssh/fuchsia_ed25519 ED25519 SHA256:<snip>
Authenticated to fe80::ca63:14ff:fe70:51db%zx-c863147051da ([fe80::ca63:14ff:fe70:51db%zx-c863147051da]:22) using "publickey"
...
$

您可以看到用戶端先建立連線,然後提供已接受的金鑰進行驗證。如果金鑰遭拒,工作階段會以以下訊息結束:

debug1: Next authentication method: keyboard-interactive
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: No more authentication methods to try.
user@fe80::ca63:14ff:fe70:51db%zx-c863147051da: Permission denied (publickey,keyboard-interactive).

這表示伺服器未設定對應金鑰的公開部分。這幾乎總是表示 Fuchsia 目標未佈建金鑰,或是本機主機和 Fuchsia 目標的金鑰不符。