Ytdyklly

This weekend I really dove into unix and got a Arch installed on an old computer and got it to serve my website.

Today I went to copy a database file from my Mac laptop to my newfangled server with scp and when I tried to log into the user that manages Nginx, I got a password failure. I'm sure I'm typing the password correctly, but just to be sure I opened up a separate terminal window, logged into my regular user, and changed the Nginx user's password from su. scp still rejected the simplified password.

I became more intrigued. I tried to ssh directly into my Nginx user with the simplified password, but it still rejected it. So I logged into my regular user again and then used su - to login to the other user. And that worked.

So why does the password work locally, when I'm logged in as another user, but not over ssh or scp?

NB: both of the users are enabled for ssh in the sshd_config file. But that's really all I know.

Here's a printout from ssh -vv, mildly edited for anonymity:

11:User-~$ ssh rserver@example.com -p 2602 -vv

OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011

debug1: Reading configuration data /Users/User/.ssh/config

debug1: Reading configuration data /etc/ssh_config

debug1: /etc/ssh_config line 20: Applying options for *

debug2: ssh_connect: needpriv 0

debug1: Connecting to example.com [67.190.118.135] port 2602.

debug1: Connection established.

debug1: identity file /Users/User/.ssh/id_rsa type 1

debug1: identity file /Users/User/.ssh/id_rsa-cert type -1

debug1: identity file /Users/User/.ssh/id_dsa type -1

debug1: identity file /Users/User/.ssh/id_dsa-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_7.2

debug1: match: OpenSSH_7.2 pat OpenSSH*

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: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa,ssh-dss-cert-v01@openssh.com,ssh-dss-cert-v00@openssh.com,ssh-dss

debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se

debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se

debug2: kex_parse_kexinit: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96

debug2: kex_parse_kexinit: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96

debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib

debug2: kex_parse_kexinit: none,zlib@openssh.com,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: curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1

debug2: kex_parse_kexinit: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519

debug2: kex_parse_kexinit: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com

debug2: kex_parse_kexinit: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com

debug2: kex_parse_kexinit: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1

debug2: kex_parse_kexinit: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1

debug2: kex_parse_kexinit: none,zlib@openssh.com

debug2: kex_parse_kexinit: none,zlib@openssh.com

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-sha1-etm@openssh.com

debug1: kex: server->client aes128-ctr hmac-sha1-etm@openssh.com none

debug2: mac_setup: found hmac-sha1-etm@openssh.com

debug1: kex: client->server aes128-ctr hmac-sha1-etm@openssh.com none

debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<2048<8192) sent

debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP

debug2: dh_gen_key: priv key bits set: 158/320

debug2: bits set: 994/2048

debug1: SSH2_MSG_KEX_DH_GEX_INIT sent

debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY

debug1: Server host key: RSA {KEY}

debug1: Host '[example.com]:2602' is known and matches the RSA host key.

debug1: Found key in /Users/User/.ssh/known_hosts:9

debug2: bits set: 999/2048

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: SSH2_MSG_SERVICE_REQUEST sent

debug2: service_accept: ssh-userauth

debug1: SSH2_MSG_SERVICE_ACCEPT received

debug2: key: /Users/User/.ssh/id_rsa (0x7fb818416130),

debug2: key: /Users/User/.ssh/id_dsa (0x0),

debug1: Authentications that can continue: publickey,password

debug1: Next authentication method: publickey

debug1: Offering RSA public key: /Users/User/.ssh/id_rsa

debug2: we sent a publickey packet, wait for reply

debug1: Authentications that can continue: publickey,password

debug1: Trying private key: /Users/User/.ssh/id_dsa

debug2: we did not send a packet, disable method

debug1: Next authentication method: password

rserver@example.com's password: 

debug2: we sent a password packet, wait for reply

debug1: Authentications that can continue: publickey,password

Permission denied, please try again.

rserver@example.com's password: 

debug2: we sent a password packet, wait for reply

debug1: Authentications that can continue: publickey,password

Permission denied, please try again.

rserver@example.com's password: 

debug2: we sent a password packet, wait for reply

debug1: Authentications that can continue: publickey,password

debug2: we did not send a packet, disable method

debug1: No more authentication methods to try.

Permission denied (publickey,password).

I know this is an old post, but I had the same problem and foud the solution so I'll post in case someone has the same issue.

In my case the problem was that I didn't have PAM active on sshd_config file, so adding the next line solved my issue:

UsePAM yes

Remember to restart sshd:

service sshd restart