我設定了一個金鑰，這樣我就可以在機器之間進行 ssh，而無需輸入密碼，並且一切正常一段時間，但突然間，某些機器上提示我輸入密碼。我驗證了密鑰 - 一切似乎都正常。我運行 ssh -v 這是輸出。據我所知，密鑰已成功驗證，那麼為什麼要求我輸入密碼？
ssh XXX.XXX.XXX.XXX -v
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to XXX.XXX.XXX.XXX [XXX.XXX.XXX.XXX] port 22.
debug1: Connection established.
debug1: identity file /nethome/username/.ssh/identity type -1
debug1: identity file /nethome/username/.ssh/id_rsa type 1
debug1: identity file /nethome/username/.ssh/id_dsa type 2
debug1: loaded 3 keys
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.3
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'XXX.XXX.XXX.XXX' is known and matches the RSA host key.
debug1: Found key in /nethome/username/.ssh/known_hosts:43
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more information
No credentials cache found
debug1: Unspecified GSS failure. Minor code may provide more information
No credentials cache found
debug1: Unspecified GSS failure. Minor code may provide more information
No credentials cache found
debug1: Next authentication method: publickey
debug1: Trying private key: /nethome/username/.ssh/identity
debug1: Offering public key: /nethome/username/.ssh/id_rsa
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Offering public key: /nethome/username/.ssh/id_dsa
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Next authentication method: password
順便說一句，我沒有看到伺服器接受身份驗證的訊息：
debug1: Server accepts key: pkalg ssh-rsa blen 277
~/.ssh/ 的模式為 700，我嘗試運行 ssh-copy-id ，這似乎有效。可以肯定的是，我在兩台機器上的 id_rsa.pub 上運行了 md5sum，它們是相同的。此外，目標電腦上的authorized_keys 的校驗和與公鑰的校驗和匹配（因為它是授權金鑰中的唯一金鑰）。
答案1
事實證明，不僅 .ssh 很重要，$HOME 權限也很重要！ $HOME 的權限設定不得高於 751。