sign_and_send_pubkey：簽名失敗：代理拒絕操作

使用 xfce 執行 xubuntu 16.04，我正在嘗試使用帶有密碼片語的 ssh 密鑰。我想將我的密碼密鑰添加到我的 ssh-agent，但我不知道為什麼我不能添加它。在我的啟動中，我沒有啟用 gnome 密鑰環或任何類似的東西。ssh-add privatekey，添加密鑰，但是當我再次嘗試 ssh 時，它只會列印兩次錯誤。一些修復程序說要在啟動時禁用 gnome 密鑰環，但我已經禁用了它。當我為我的樹莓派替換 ssh 密鑰時，這一切都發生了。

> OpenSSH_7.2p2 Ubuntu-4ubuntu2.1, OpenSSL 1.0.2g  1 Mar 2016
debug1: Reading configuration data /home/potato/.ssh/config
debug1: /home/potato/.ssh/config line 1: Applying options for paj
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 111.229.105 [111.229.105] port 22253.
debug1: Connection established.
debug1: identity file /home/potato/.ssh/hplaptop_to_pi type 1
debug1: key_load_public: No such file or directory
debug1: identity file /home/potato/.ssh/hplaptop_to_pi-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.7p1 Raspbian-5+deb8u3
debug1: match: OpenSSH_6.7p1 Raspbian-5+deb8u3 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 111.229.105:22253 as 'pi'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve22219-sha256@libssh.org
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:zrjeaaHD8TjzsdsdssssA2fXnG3gxp2U
debug1: Host '[111.229.105]:22253' is known and matches the ECDSA host key.
debug1: Found key in /home/potato/.ssh/known_hosts:2
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/potato/.ssh/hplaptop_to_pi
debug1: Server accepts key: pkalg ssh-rsa blen 535
sign_and_send_pubkey: signing failed: agent refused operation
debug1: Offering RSA public key: potato@potato-HP-tomato
debug1: Authentications that can continue: publickey
debug1: Offering RSA public key: potato@hplaptop
debug1: Authentications that can continue: publickey
debug1: Offering RSA public key: potato@hplaptop
debug1: Server accepts key: pkalg ssh-rsa blen 535
sign_and_send_pubkey: signing failed: agent refused operation
debug1: Offering RSA public key: rsa-key-20141222
debug1: Authentications that can continue: publickey
debug1: Offering RSA public key: potato@potatolaptop
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).

因此，經過數小時無意識的Google搜尋和幫助，問題被發現了。我正在使用 ssh-keygen 生成我的 ssh 密鑰，並添加了一個附加參數“-o”，它為 openSSH 生成了新格式的密鑰。問題是我的 gnome-keyring 不支持這樣的密鑰，因為這些密鑰具有 Ed255519 簽名方案。Gnome-keyring 自 3.20 起不支持該功能。我恢復到 RSA 並且沒有更多問題了！

在我的情況下，問題是 GNOME 密鑰環為要使用的 ssh 密鑰持有無效的密碼。在花費大量時間解決此問題後，我執行seahorse並找到包含空字元串的條目。

我只能猜測這是由於在第一次使用時輸入錯誤密碼造成的，然後可能會取消請求者左右以回退到命令行。

• 使用正確的密碼更新條目立即解決了問題。
• 刪除該條目（從“登錄”密鑰環）並在第一個提示時重新輸入密碼（並選中相應的複選框）也可以解決此問題。

現在代理從名為“login”的登錄密鑰環中解鎖的正確密碼，不再要求輸入密碼或“拒絕操作”。當然是 YMMV。

引用自：https://unix.stackexchange.com/questions/350768