应该是电信出口进口太烂把，家里移动的网， do 旧金山的 ss ， youtube720p 能看，学校电信网， ss 没变， youtube 根本没发看。也有可能是电信墙格外高。。。

@Bardon @c742435 @ryd994 谢谢大家,问题已经解决了
昨天没法使用公钥认证的问题是.ssh 目录的权限是 770
然而我一直没有找到问题所在,在 sshd_config 里面将这一项:
AuthorizedKeysFile .ssh/authorized_keys 修改为了
AuthorizedKeysFile ~/.ssh/authorized_keys
所以在今天我修改权限以后,sshd 一直找不到该文件,今天看到了
将其该回来了,于是就能够公钥认证了.
我认为是在还没有登录以前 HOME 变量是不存在的,所以找不到~/.ssh/authorized_keys
是我脑子抽了,谢谢大家

@Bardon 在我本机是有 home/cxy/.ssh/id_rsa 的.远端上也有 publuc key , root 和普通用户的家目录都有,因为 root 是能够使用公钥登录的.
一下是 ssh -vvv 的信息:
OpenSSH_6.7p1 Debian-5, OpenSSL 1.0.1k 8 Jan 2015
debug1: Reading configuration data /home/cxy/.ssh/config
debug1: /home/cxy/.ssh/config line 1: Applying options for TX
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Hostname has changed; re-reading configuration
debug1: Reading configuration data /home/cxy/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 182.254.209.40 [182.254.209.40] port 2200.
debug1: Connection established.
debug1: identity file /home/cxy/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /home/cxy/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/cxy/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/cxy/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/cxy/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/cxy/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/cxy/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/cxy/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.7p1 Debian-5
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH_5* compat 0x0c000000
debug2: fd 3 setting O_NONBLOCK
debug3: put_host_port: [182.254.209.40]:2200
debug3: load_hostkeys: loading entries for host "[182.254.209.40]:2200" from file "/home/cxy/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /home/cxy/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],ssh-rsa
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: [email protected],[email protected],ssh-rsa,[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],[email protected],arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],[email protected],arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1,[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1,[email protected],[email protected],[email protected],[email protected],hmac-md5,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-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: 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,[email protected]
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,[email protected]
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit: none,[email protected]
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: setup [email protected]
debug1: kex: server->client aes128-ctr [email protected] none
debug2: mac_setup: setup [email protected]
debug1: kex: client->server aes128-ctr [email protected] none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<3072<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: bits set: 1563/3072
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: RSA 90:c1:b4:87:e3:29:df:bd:1e:f6:42:8a:89:b7:86:01
debug3: put_host_port: [182.254.209.40]:2200
debug3: put_host_port: [182.254.209.40]:2200
debug3: load_hostkeys: loading entries for host "[182.254.209.40]:2200" from file "/home/cxy/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /home/cxy/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys
debug3: load_hostkeys: loading entries for host "[182.254.209.40]:2200" from file "/home/cxy/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /home/cxy/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys
debug1: Host '[182.254.209.40]:2200' is known and matches the RSA host key.
debug1: Found key in /home/cxy/.ssh/known_hosts:1
debug2: bits set: 1548/3072
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: /home/cxy/.ssh/id_rsa (0x7f353b34b1c0),
debug2: key: /home/cxy/.ssh/id_dsa ((nil)),
debug2: key: /home/cxy/.ssh/id_ecdsa ((nil)),
debug2: key: /home/cxy/.ssh/id_ed25519 ((nil)),
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic,password
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup gssapi-keyex
debug3: remaining preferred: gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-keyex
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug2: we did not send a packet, disable method
debug3: authmethod_lookup gssapi-with-mic
debug3: remaining preferred: publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-with-mic
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available

debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available

debug1: Unspecified GSS failure. Minor code may provide more information


debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available

debug2: we did not send a packet, disable method
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/cxy/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Trying private key: /home/cxy/.ssh/id_dsa
debug3: no such identity: /home/cxy/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /home/cxy/.ssh/id_ecdsa
debug3: no such identity: /home/cxy/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/cxy/.ssh/id_ed25519
debug3: no such identity: /home/cxy/.ssh/id_ed25519: No such file or directory
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

@ryd994 这个是 /var/log/secure 文件的信息.不知道是不是这个,但是这个信息更少,只有一条密码错误和密码正确
Nov 1 09:22:43 localhost sshd[2242]: Connection closed by 113.140.84.101
Nov 1 09:23:00 localhost sshd[2243]: Failed password for cxy from 113.140.28.66 port 16310 ssh2
Nov 1 09:23:06 localhost sshd[2243]: Accepted password for cxy from 113.140.28.66 port 16310 ssh2
Nov 1 09:23:50 localhost sudo: cxy : TTY=pts/1 ; PWD=/home/cxy ; USER=root ; COMMAND=/usr/bin/tail -F /var/log/secure-20151101
Nov 1 09:24:23 localhost sudo: cxy : TTY=pts/1 ; PWD=/home/cxy ; USER=root ; COMMAND=/bin/cat /var/log/secure
Nov 1 09:26:10 localhost sudo: cxy : TTY=pts/2 ; PWD=/home/cxy ; USER=root ; COMMAND=/bin/cat /var/log/secure /var/log/secure-20151022 /var/log/secure-20151025 /var/log/secure-20151101
Nov 1 09:27:01 localhost sudo: cxy : TTY=pts/2 ; PWD=/home/cxy ; USER=root ; COMMAND=/bin/cat /var/log/secure-20151101
Nov 1 09:29:02 localhost sudo: cxy : TTY=pts/2 ; PWD=/home/cxy ; USER=root ; COMMAND=/sbin/service sshd restart
Nov 1 09:29:02 localhost sshd[1019]: Received signal 15; terminating.