SSH Key: “Permissions 0644 for 'id_rsa.pub' are too open.” on mac

Question

I generate a ssh key pair on my mac and add the public key to my ubuntu server(in fact, it is a virtual machine on my mac),but when I try to login the ubuntu server,it says:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @         WARNING: UNPROTECTED PRIVATE KEY FILE!          @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Permissions 0644 for '/Users/tudouya/.ssh/vm/vm_id_rsa.pub' are too open. It is required that your private key files are NOT accessible by others. This private key will be ignored. bad permissions: ignore key: /Users/tudouya/.ssh/vm/vm_id_rsa.pub Permission denied (publickey,password). 

I have tried many ways to solve this, change the key file mode, change the folder mode,as some answer on stackoverflow,but it doesn't work.
the key file permission:

vm dir: drwxr-xr-x   4 tudouya  staff    136  4 29 10:37 vm  key file: -rw-------  1 tudouya  staff  1679  4 29 10:30 vm_id_rsa -rw-r--r--  1 tudouya  staff   391  4 29 10:30 vm_id_rsa.pub 

please give me some idea... =========================================

I write the host infomation to ssh_config:

Host ubuntuvm     Hostname 10.211.55.17     PreferredAuthentications publickey     IdentityFile /Users/tudouya/.ssh/vm/vm_id_rsa.pub 

I run command "ssh -v ubuntuvm",it displays:

ssh -v ubuntuvm OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011 debug1: Reading configuration data /etc/ssh_config debug1: /etc/ssh_config line 20: Applying options for * debug1: /etc/ssh_config line 103: Applying options for * debug1: /etc/ssh_config line 175: Applying options for ubuntuvm debug1: Connecting to 10.211.55.17 [10.211.55.17] port 22. debug1: Connection established. debug1: identity file /Users/tudouya/.ssh/vm/vm_id_rsa.pub type 1 debug1: identity file /Users/tudouya/.ssh/vm/vm_id_rsa.pub-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.2 debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1p1 Ubuntu-8 debug1: match: OpenSSH_6.6.1p1 Ubuntu-8 pat OpenSSH* debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr [email protected] none debug1: kex: client->server aes128-ctr [email protected] 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 55:6d:4f:0f:23:51:ac:8e:70:01:ec:0e:62:9e:1c:10 debug1: Host '10.211.55.17' is known and matches the RSA host key. debug1: Found key in /Users/tudouya/.ssh/known_hosts:54 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,password debug1: Next authentication method: publickey debug1: Offering RSA public key: /Users/tudouya/.ssh/vm/vm_id_rsa.pub debug1: Server accepts key: pkalg ssh-rsa blen 279 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @         WARNING: UNPROTECTED PRIVATE KEY FILE!          @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Permissions 0644 for '/Users/tudouya/.ssh/vm/vm_id_rsa.pub' are too open. It is required that your private key files are NOT accessible by others. This private key will be ignored. bad permissions: ignore key: /Users/tudouya/.ssh/vm/vm_id_rsa.pub debug1: No more authentication methods to try. Permission denied (publickey,password). 

Answer 1

I suggest you to do:

chmod 400 ~/.ssh/id_rsa

It works fine for me.