Permission denied (publickey,password,keyboard-interactive) error

Question

I am trying to scp from Bitbucket pipeline wto Windows Server 2016. The Windows server has Win32-OpenSSH installed.

Command output:

+ scp -v sample.conf [email protected]:/C:/Users/john.doe
Executing: program /usr/bin/ssh host xx.yyy.zzz.xyz, user john.doe, command scp -v -d -t /C:/Users/john.doe
OpenSSH_7.7p1, LibreSSL 2.7.4
debug1: Reading configuration data /home/gradle/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to xx.yyy.zzz.xyz [xx.yyy.zzz.xyz] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /home/gradle/.ssh/id_pipelines type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/gradle/.ssh/id_pipelines-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.7
debug1: Remote protocol version 2.0, remote software version OpenSSH_for_Windows_7.7
debug1: match: OpenSSH_for_Windows_7.7 pat OpenSSH* compat 0x04000000
debug1: Authenticating to xx.yyy.zzz.xyz:22 as 'john.doe'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: rsa-sha2-512
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ssh-rsa SHA256:wkXf3e9jgd5W/QY/LwBF41XgeJIC/wLZBeavZI/xYM
debug1: Host 'xx.yyy.zzz.xyz' is known and matches the RSA host key.
debug1: Found key in /home/gradle/.ssh/known_hosts:3
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Trying private key: /home/gradle/.ssh/id_pipelines
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: keyboard-interactive
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: password
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug1: Authentications that can continue: publickey,password,keyboard-interactive
Permission denied, please try again.
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug1: Authentications that can continue: publickey,password,keyboard-interactive
Permission denied, please try again.
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: No more authentication methods to try.
[email protected]: Permission denied (publickey,password,keyboard-interactive).
lost connection

Uncommented lines in C:\ProgramData\ssh\sshd_config

Port 22
PubkeyAuthentication yes
AuthorizedKeysFile  .ssh/authorized_keys
PasswordAuthentication yes
PermitEmptyPasswords no
Subsystem   sftp    sftp-server.exe

On Windows server, public key is present in C:\Users\john.doe\.ssh\authorized_keys

I am just not sure what's wrong with the configuration. Any idea?

Solution

Maybe it is a file permission problem.

In the file contrib/win32/win32compat/w32-sshfileperm.c, there is this comment:

/*
 * The function is to check if current user is secure to access to the file. 
 * Check the owner of the file is one of these types: Local Administrators groups, system account, current user account
 * Check the users have access permission to the file don't voilate the following rules:
 *        1. no user other than local administrators group, system account, and pwd user have write permission on the file
 *        2. sshd account can only have read permission
 * Returns 0 on success and -1 on failure
 */
int
check_secure_file_permission(const char *input_path, struct passwd * pw)

You need to check that permissions are correct:

• On the user's home directory (C:\Users\john.doe)
• On the .ssh directory (C:\Users\john.doe\.ssh)
• And on the authorized_keys file (C:\Users\john.doe\.ssh\authorized_keys).

Reference:

[1] https://askubuntu.com/questions/1078884/key-rejection-when-do-ssh

Comments

[Technext]

That exactly was the issue and it happened because i was trying scp with two accounts (mine and a build user's a/c). Since i was able to login remotely using either of these accounts and since both have admin rights on the Windows server, i accidentally ended up modifying my authorized_keys file using the build user's account while troubleshooting. Never thought i would have messed up things like this on Windows. Now i realize permissions matter on Windows as well as far as SSH is concerned. Thank you for pasting the comment from w32-sshfileperm.c file Marcelo! That really helped. :)