Ubuntu 16.04中对本地主机的无密码ssh

Question

我似乎无法设置到localhost的无密码ssh连接，我也不知道为什么。

在~/.ssh中我有id_rsa，authorized_keys，id_rsa.pub和known_hosts

diff authorized_keys id_rsa

一事无成

ls -al 

给出

-rw-------  1 long long 1675 Jun  3 02:24 authorized_keys
-rw-------  1 long long 1675 Jun  3 02:23 id_rsa
-rw-r--r--  1 long long  438 Jun  3 02:23 id_rsa.pub
-rw-r--r--  1 long long  444 Jun  3 02:57 known_hosts

.ssh文件夹的权限为

drwx------  2 long long 4096 Jun  3 03:29 .ssh

我的主文件夹的权限是

drwxr-xr-x 23 long long 4096 Jun  3 02:23 long

在/etc/ssh/sshd_config中，我将PermitEmptyPasswords改为yes

的详细输出

ssh -v localhost

是

OpenSSH_7.2p2 Ubuntu-4ubuntu2.4, OpenSSL 1.0.2g  1 Mar 2016
debug1: Reading configuration data /home/long/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: identity file /home/long/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /home/long/.ssh/id_rsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 
Ubuntu-4ubuntu2.4
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to localhost:22 as 'long'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-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:XK9dVu0tdSA4YSbcifizhFhigKZU2LZl+W91Eesdimw
debug1: Host 'localhost' is known and matches the ECDSA host key.
debug1: Found key in /home/long/.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_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/long/.ssh/id_rsa
debug1: Authentications that can continue: publickey,password
debug1: Offering RSA public key: long@long-MS-7885-Invalid-entry-length-16-
Fixed-up-to-11
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: password
long@localhost's password: 

我们将非常感谢您的帮助。

Answer 1

PermitEmptyPasswords设置允许SSH接受空白密码，但这并不意味着SSH不会提示输入密码：

PermitEmptyPasswords -当允许密码身份验证时，它指定服务器是否允许登录到具有空密码字符串的帐户。默认为否。- man sshd_config

要允许在没有密码的情况下登录，需要设置公钥身份验证。正如Fox所提到的，命令diff authorized_keys id_rsa的输出建议您的authorized_keys文件中只有私有SSH密钥；该文件不应该有任何私钥。您可以运行cat ~/.ssh/id_rsa.pub > ~/.ssh/authorized_keys来替换为您的公钥。

然后您就可以去掉那个空白密码:)