linux - Linux ssh 无密码登录不起作用？

Question

bharathi-1397@bharathi-1397:~$ ssh-keygen 
Generating public/private rsa key pair.
Enter file in which to save the key (/home/local/bharathi-1397/.ssh/id_rsa): 
/home/local/bharathi-1397/.ssh/id_rsa already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/local/bharathi-1397/.ssh/id_rsa.
Your public key has been saved in /home/local/bharathi-1397/.ssh/id_rsa.pub.
The key fingerprint is:
de:e3:e5:f6:a3:8e:83:76:f0:7d:d6:e1:b3:d6:cc:93 bharathi-1397@bharathi-1397
The key's randomart image is:
+--[ RSA 2048]----+
|                 |
|                 |
|                 |
|                 |
|        S        |
|       ...     . |
|        .+o.. .++|
|        o.+=o +E=|
|       . .o++=oo+|
+-----------------+

接下来我从 .ssh/id_rsa.pub 复制内容并存储在远程机器中。

 bharathikannan.r@172.20.2.7:~$ mkdir .ssh
 bharathikannan.r@172.20.2.7:~$ vi authorized_keys

将复制的内容粘贴到 authorized_keys 但下次我尝试登录时会询问密码为什么？ssh bharathikannan.r@172.20.2.7 bharathikannan.r@172.20.2.7的密码：

为什么它要求密码？. 我按照正确的步骤操作。不知道为什么要密码？

ssh -v bharathikannan.r@172.20.2.7
OpenSSH_5.8p1 Debian-7ubuntu1, OpenSSL 1.0.0e 6 Sep 2011
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to integ-build3 [192.168.5.173] port 22.
debug1: Connection established.
debug1: identity file /home/local/bharathi-1397/.ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
debug1: identity file /home/local/bharathi-1397/.ssh/id_rsa-cert type -1
debug1: identity file /home/local/bharathi-1397/.ssh/id_dsa type -1
debug1: identity file /home/local/bharathi-1397/.ssh/id_dsa-cert type -1
debug1: identity file /home/local/bharathi-1397/.ssh/id_ecdsa type -1
debug1: identity file /home/local/bharathi-1397/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3
debug1: match: OpenSSH_4.3 pat OpenSSH_4*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.8p1 Debian-7ubuntu1
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: Server host key: RSA 66:3e:67:25:65:22:f0:70:3d:e3:ce:3b:14:49:7e:76
debug1: Host '172.20.2.7' is known and matches the RSA host key.
debug1: Found key in /home/local/bharathi-1397/.ssh/known_hosts:5
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/local/bharathi-1397/.ssh/id_rsa
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug1: Trying private key: /home/local/bharathi-1397/.ssh/id_dsa
debug1: Trying private key: /home/local/bharathi-1397/.ssh/id_ecdsa
debug1: Next authentication method: password
bharathikannan.r@172.20.2.7's password: 

Answer 1

根据您的描述，您在您的家中创建了 .ssh 目录，然后在同一目录中创建了 .authorized_keys 文件（您的家，不在 ~/.ssh/ 中）。请确保文件在正确的位置。

此外，以下命令可以轻松设置您：

user@host:~$ ssh-copy-id user@otherhost

希望有帮助。

Answer 2

您可能没有 ~/.ssh 目录或没有 .ssh/authorized_keys 文件。请注意，在手动创建 ~/.ssh/authorized_keys 文件时，您很容易获得错误的权限之一。

chmod 700 ~/.ssh
chmod 600 ~/.ssh/id_rsa
chmod 644 ~/.ssh/id_rsa.pub  
chmod 644 ~/.ssh/authorized_keys
chmod 644 ~/.ssh/known_hosts
restorecon -R ~/.ssh

真正的问题是最后一个，SELINUX（这是我偶然发现的，我总是这样做）。您可以随时尝试将其设置为允许和/或检查 audit.log。

# ll -Z ~/.ssh/authorized_keys
-rw-r--r--. root root unconfined_u:object_r:admin_home_t:s0 /root/.ssh/authorized_keys
# restorecon -R ~/.ssh
# ll -Z ~/.ssh/authorized_keys
-rw-r--r--. root root unconfined_u:object_r:ssh_home_t:s0 /root/.ssh/authorized_keys

失败所有这些登录到目标机器并创建完整的密钥结构

ssh-keygen

Answer 3

它要求输入密码，因为您没有告诉客户端机器使用什么密钥。

您可以通过以下两种方式之一执行此操作：

1）当您终端进入远程机器时，使用以下命令：

ssh -i /path/to/your/privatekey user@host

2）~/.ssh/config在您的客户端计算机上创建文件并插入以下内容：

Host your.hostname.tld
IdentityFile /path/to/your/privatekey

如果您要使用多个不同的键，则方法 1 很棒。每次连接到给定主机时，方法 2 都是自动的。

Answer 4

.ssh目录应该在700两个系统上。

drwx------ .ssh