"Failed to connect to the host via ssh: Permission denied (publickey).", [duplicate] - ssh

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 hmac-md5-etm#openssh.com none
debug1: kex: client->server aes128-ctr hmac-md5-etm#openssh.com 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.

Answer 2

debug1: identity file /Users/tudouya/.ssh/vm/vm_id_rsa.pub type 1
It appears that you're trying to use the wrong key file. The file with the ".pub" extension contains the public portion of the key. The corresponding file without the ".pub" extension contains the private part of the key. When you run an ssh client to connect to a remote server, you have to provide the private key file to the ssh client.
You probably have a line in the your .ssh/config file (or /etc/ssh_config) which looks like this:
IdentityFile .../.ssh/vm/vm_id_rsa.pub
You need to remove the ".pub" extension from the filename:
IdentityFile .../.ssh/vm/vm_id_rsa

Answer 3

Key should be readable by the logged in user.
Try this:
chmod 400 ~/.ssh/Key file
chmod 400 ~/.ssh/vm_id_rsa.pub

Answer 4

chmod 400 path/to/filename
This work for me. When I did this file I am able to connect to my EC2 instance

Answer 5

change your KEY permission to
chmod 400 your_key.pem
It should work !

Answer 6

After running below command it works for me
sudo chmod 600 /path/to/my/key.pem

Answer 7

In my case, it was a .pem file. Turns out holds good for that too. Changed permissions of the file and it worked.
chmod 400 ~/.ssh/dev-shared.pem
Thanks for all of those who helped above.

Answer 8

SSH keys are meant to be private so a 644 permission is too open.
Binary references to set Permissions
r(read) = 4
w(write) = 2
x(execute) = 1
So by adding these numbers and by passing the summed digit to chmod command,We set the permission of file/directory.
The first digit sets permission for the owner, second digit for group and the third one for all other users on the system who have no right to the file.
A permission of 644 means
(4+2) = read/write permission for the owner
(4) = read permission for the group
(4) = read permission for all other users
By changing the the permission of the file to 400 using
chmod 400 <filename>
solves the issue. As it makes the key read-only accessible to the owner.
Ref: https://www.linux.com/training-tutorials/understanding-linux-file-permissions/

Answer 9

Lot's of similar answers but no explanations...
The error is thrown because the private key file permissions are too open. It is a security risk.
Change the permissions on the private key file to be minimal (read only by owner)
Change owner chown <unix-name> <private-key-file>
Set minimal permissions (read only to file owner) chmod 400 <private-key-file>

Answer 10

If the keys are in the ~/.ssh directory , use
chmod 400 ~/.ssh/id_rsa
If the keys are in different directory, use
chmod 400 directory_path/id_rsa
This worked for me.

Answer 11

chmod 600 id_rsa
Run above command from path where key is stored in vm ex: cd /home/opc/.ssh

Answer 12

I have similar issue and solved it by changing the permission of the respective files and folder worked for me.
This is the solution which is worked for me:
$ chmod 0600 ~/.ssh/id_rsa.pub
$ chmod 0600 ~/.ssh/authorized_keys
$ chmod 0600 ~/.ssh/id_rsa
$ chmod 0700 ~/.ssh

Answer 13

You have to run the command bellow
chmod 400 /path/to/my/key.pem

Answer 14

As for me, the default mode of id_rsa is 600, which means readable and writable.
After I push this file to a git repo and pull it from another pc, sometimes the mode of the private key file becomes -rw-r--r--.
When I pull the repo with ssh after specify the private key file, it failed and prompted warnings the same with you. Following is my script.
ssh-agent bash -c "ssh-add $PATH_OF_RSA/id_rsa; \
git pull git#gitee.com:someone/somerepo.git "
I fix this problem just by changing the mode to 600.
chmod 600 $PATH_TO_RSA/id_rsa

Answer 15

giving permision 400 makes the key private and not accessible by someone unknown. It makes the key as a protected one.
chmod 400 /Users/tudouya/.ssh/vm/vm_id_rsa.pub

Answer 16

Just run below to your pem's
sudo chmod 600 /path/to/my/key.pem

Answer 17

If youre using a .ssh/config file try to
chmod 0400 .ssh/config
then:
chmod 0400 .ssh/<<KEYFILE_PATH>>

Answer 18

This should do the trick:
chmod 600 id_rsa

Answer 19

chmod 400 /etc/ssh/* works for me.

Answer 20

Those who suggested chmod 400 id_rsa.pub did not sound right at all. It was quite possible that op used pub key instead of private key to ssh.
So it might be as simple as ssh -i /Users/tudouya/.ssh/vm/vm_id_rsa (the private key) user#host to fix it.
--- update ---
Check this article https://www.digitalocean.com/community/tutorials/how-to-set-up-ssh-keys--2 for how to set up ssh key

Answer 21

I had this issue with a macbook m1, I later realized that i was missing sudo from the connection script
sudo ssh -i "key.pem" ubuntu#IP_Address
Ensure you are not missing the sudo in your connection script if you are using a macbook.

Answer 22

This problem had a quick and easy fix. You just had to change the permissions on the pem file using the following command.
chmod 400 /Users/yourUserName/pathOfYourFile/fileName.pem
This command will make the file read only and remove all other permissions on the file

Answer 23

There has been a lot of great explanation above, so I recommend reading and understanding.
Here is my simple step by step solution:
On your terminal, run:
open ~/.ssh/config
In your file, you will see something similar to this (in my personal case):
Host *
IgnoreUnknown UseKeychain
AddKeysToAgent yes
IdentityFile ~/.ssh/id_ed25519.pub
or like this (as per the example in this question).
Hostname 10.211.55.17
PreferredAuthentications publickey
IdentityFile /Users/tudouya/.ssh/vm/vm_id_rsa.pub
Remove the ".pub" extention from the last line, which should look like:
Hostname 10.211.55.17
PreferredAuthentications publickey
IdentityFile /Users/tudouya/.ssh/vm/vm_id_rsa
or in my case:
Host *
IgnoreUnknown UseKeychain
AddKeysToAgent yes
IdentityFile ~/.ssh/id_ed25519
Save the file and test your ssh connection.

Answer 24

i had similar issues and this was what i did and it worked.
sudo ssh -i webhost.pem ubuntu#ipaddress

Answer 25

I removed the .pub file, and it worked.