我正在尝试在两台计算机之间设置无密码 SSH 配置，但遇到问题。我遵循了很多方法，但都没有成功。这是我已采取的步骤
在客户端上生成身份验证密钥。 （当提示输入密码时按 Enter 键）
[root@box1:.ssh/$] ssh-keygen -t rsa将公钥复制到服务器。
[root@box1:.ssh/$] scp id_rsa.pub root@box2:.ssh/authorized_keys验证授权密钥已在服务器上成功创建
执行以下命令：
[root@box1:.ssh/$] ssh root@box2 ls
仍然提示我输入密码。我读到一篇指南的注释说“取决于正在运行的 SSH 版本...”（尽管它没有指定哪些版本需要这个），它可能需要：
- .ssh/authorized_keys2 中的公钥
- .ssh的权限为700
- .ssh/authorized_keys2 的权限为 640
我也按照这些步骤进行操作，但没有成功。我已经验证了 home、root 和 .ssh 目录不可按组写入（根据https://unix.stackexchange.com/tags/ssh/info）。
有人知道我缺少什么吗？
谢谢
编辑：我还使用 ssh-copy-id 命令将公钥复制到第二个盒子并生成文件.ssh/authorized_keys。
[root@box1:.ssh/$] ssh-copy-id -i id_rsa.pub root@box2
EDIT2：包括版本信息
// box1（系统密钥生成于）
- Linux 2.6.34
- OpenSSH_5.5p1 Debian-6、OpenSSL 0.9.8o 2010 年 6 月 1 日
// 盒子2
- Linux 2.6.33
- Dropbear客户端 v0.52
EDIT3：调试输出
[root@box1:.ssh/$] ssh -vvv root@box2 ls
OpenSSH_5.5p1 Debian-6, OpenSSL 0.9.8o 01 Jun 2010
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to box2 [box2] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug3: Not a RSA1 key file /root/.ssh/id_rsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /root/.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 /root/.ssh/id_rsa-cert type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: Remote protocol version 2.0, remote software version dropbear_0.52
debug1: no match: dropbear_0.52
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.5p1 Debian-6
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit:
diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-
group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit:
[email protected],[email protected],ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-
cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysatoe
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-
cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysatoe
debug2: kex_parse_kexinit:
hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-
sha1-96,hmac-md5-96
debug2: kex_parse_kexinit:
hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-
sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit: diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:
aes128-ctr,3des-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes256-cbc,twofish256-cbc,twofish-
cbc,twofish128-cbc,blowfish-cbc
debug2: kex_parse_kexinit:
aes128-ctr,3des-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes256-cbc,twofish256-cbc,twofish-
cbc,twofish128-cbc,blowfish-cbc
debug2: kex_parse_kexinit: hmac-sha1-96,hmac-sha1,hmac-md5
debug2: kex_parse_kexinit: hmac-sha1-96,hmac-sha1,hmac-md5
debug2: kex_parse_kexinit: zlib,[email protected],none
debug2: kex_parse_kexinit: zlib,[email protected],none
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_setup: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_setup: found hmac-md5
debug1: kex: client->server aes128-ctr hmac-md5 none
debug2: dh_gen_key: priv key bits set: 132/256
debug2: bits set: 515/1024
debug1: sending SSH2_MSG_KEXDH_INIT
debug1: expecting SSH2_MSG_KEXDH_REPLY
debug3: check_host_in_hostfile: host 192.168.20.10 filename
/root/.ssh/known_hosts
debug3: check_host_in_hostfile: host 192.168.20.10 filename
/root/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 3
debug1: Host 'box2' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:3
debug2: bits set: 522/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /root/.ssh/id_rsa (0x54b1c340)
debug2: key: /root/.ssh/id_dsa ((nil))
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred
gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /root/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,password
debug1: Trying private key: /root/.ssh/id_dsa
debug3: no such identity: /root/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
EDIT4：另一个有趣的发展。我没有在 box1（运行 OpenSSH）上生成密钥并将它们复制到 box2（运行 dropbear），而是相反：
[root@box2:.ssh/$] dropbearkey -t rsa -f id_rsa
[root@box2:.ssh/$] dropbearkey -y -f id_rsa | grep "^ssh-rsa" >> authorized_keys
[root@box2:.ssh/$] scp authorized_keys root@box1:.ssh/
这样，只有当我指定 ID 文件时，我才能成功地从 box2 到 box1 发出无密码命令：
[root@box2:.ssh/$] ssh -i id_rsa root@box1 ls
仍然无法从 box1 (OpenSSH) 向 box2 (dropbear) 发出命令。
答案1
我找到了问题的根源。里面有一条/var/log/messages关于奇怪的所有权的模糊信息给了我提示。于是我检查了一下， /root、/root/.ssh、的权限/root/.ssh/*都是正确的（700），但所有权是default.default。我不知道这是怎么发生的......但我跑了：
[root@box1:.ssh/$] chown root.root /root
[root@box1:.ssh/$] chown root.root /root/.ssh
[root@box1:.ssh/$] chown root.root /root/.ssh/*
将所有权更改为 root 和无密码登录是双向的。
答案2
您能确认是否允许 root 登录 ssh 吗？ keygen 通常会提示输入密码。您在注册机时设置过密码吗？如果是，则提示输入该密码。如果您希望无头帐户进行无密码访问，请创建无密码私钥。
答案3
从调试来看：debug2: key_type_from_name: unknown key type '-----BEGIN'看起来您的authorized_keys文件格式不正确。
删除第一行（两行？）、最后一行（-----End）和任何其他换行符应该可以解决问题。
Linux 的密钥文件不使用与许多 Windows（和某些 Linux）生成器相同的密钥文件。例如，PuTTY 启动私钥，---- BEGIN SSH2 PUBLIC KEY ----但 Linux 正在寻找ssh-rsa AAAAB3NzaC1yc2E...G8HAaGz8ob6IXx3841ASs= Example@server
完整的规范可以在此处找到：http://man.he.net/man5/authorized_keys
但简短的版本是： *没有换行符
*以协议（ssh-rsa、ssh-dsa）开头
*公钥
*以“=”和密钥名称结尾
让我知道这是否有帮助