ssh issue

Hello,
I have two computers at my desk, let's call them A and B. I have some tasks that can only be performed on one of them and some on the other, so I need to be able to ssh from one to the other and vice versa to transfer files, etc.
A can ssh to B without problem: I even copied the public key across so that the login is passwordless. File transfer works fine and everything is ok. However, B cannot ssh to A smoothly. My command is usually this:

ssh user@ip.address

whereupon I'm prompted for a password; I give the correct one, but it says "permission denied", and after three tries it returns to command prompt.
If I try this:

ssh root@ip.address

and I give the root password, then I do connect to A, after which I can

su user

to use the specific user.
The question is, how can I enable ssh with the user? I tried mucking about with /etc/ssh/sshd_config on both machines, tried adding the user to AllowUsers, I shared the public keys in the authorized_keys file in .ssh, but nothing has worked.
I'm happy to provide any details you may require in helping me.
Thanks in advance

what does it say when you do the below on A.

ssh user@localhoost

It gives the same response as with B. I'm asked for a password, I give the right one, and tells me permission is denied. If I try

ssh root@localhost

and I give the root password, then I can login into A no problem.

You need to run ssh with more verbosity to understand why authentication is failing.

ssh -vvv username@host

On the server end, look in the logs. /var/log/auth.log will give you a pretty good idea about what happens when you try to login, look for messages that contain "sshd".

There is no /var/log/auth.log file.
In verbose mode, it says many things, anything in particular I should pay attention to?

Leo B - What OS are you running?

Things to look for as a start:
restart the sshd service on both boxes (as root)
Try:

ssh -vvv hostname

and post the result.

A is running Redhat 5, B is running Fedora 11.
I restarted sshd with

/etc/init.d/sshd restart

This is the output:

OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to hostname [ip.address] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug3: Not a RSA1 key file /root/.ssh/id_rsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /root/.ssh/id_rsa type 1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: loaded 2 keys
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3
debug1: match: OpenSSH_4.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.3
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: 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,rijndael-cbc@lysator.liu.se
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,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,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: 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,rijndael-cbc@lysator.liu.se
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,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
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_init: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_init: found hmac-md5
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 118/256
debug2: bits set: 528/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 2
debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 2
debug1: Host 'hostname' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:2
debug2: bits set: 493/1024
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: /root/.ssh/id_rsa (0x2b7fe3eecb00)
debug2: key: /root/.ssh/id_dsa ((nil))
debug3: input_userauth_banner

Unauthorised Access Is Prohibited

debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug3: start over, passed a different list publickey,gssapi-with-mic,password
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
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
debug3: Trying to reverse map address ip.address.
debug1: Unspecified GSS failure.  Minor code may provide more information
Server not found in Kerberos database

debug1: Unspecified GSS failure.  Minor code may provide more information
Server not found in Kerberos database

debug1: Unspecified GSS failure.  Minor code may provide more information
Server not found in Kerberos database

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 public key: /root/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug1: Trying private key: /root/.ssh/id_dsa
debug3: no such identity: /root/.ssh/id_dsa
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
root@hostname's password:
debug3: packet_send2: adding 64 (len 57 padlen 7 extra_pad 64)
debug2: we sent a password packet, wait for reply
debug1: Authentication succeeded (password).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug1: Entering interactive session.
debug2: callback start
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 0
debug3: tty_make_modes: ospeed 38400
debug3: tty_make_modes: ispeed 38400
debug3: tty_make_modes: 1 3
debug3: tty_make_modes: 2 28
debug3: tty_make_modes: 3 127
debug3: tty_make_modes: 4 21
debug3: tty_make_modes: 5 4
debug3: tty_make_modes: 6 255
debug3: tty_make_modes: 7 255
debug3: tty_make_modes: 8 17
debug3: tty_make_modes: 9 19
debug3: tty_make_modes: 10 26
debug3: tty_make_modes: 12 18
debug3: tty_make_modes: 13 23
debug3: tty_make_modes: 14 22
debug3: tty_make_modes: 18 15
debug3: tty_make_modes: 30 0
debug3: tty_make_modes: 31 0
debug3: tty_make_modes: 32 0
debug3: tty_make_modes: 33 0
debug3: tty_make_modes: 34 0
debug3: tty_make_modes: 35 0
debug3: tty_make_modes: 36 1
debug3: tty_make_modes: 37 0
debug3: tty_make_modes: 38 1
debug3: tty_make_modes: 39 1
debug3: tty_make_modes: 40 0
debug3: tty_make_modes: 41 1
debug3: tty_make_modes: 50 1
debug3: tty_make_modes: 51 1
debug3: tty_make_modes: 52 0
debug3: tty_make_modes: 53 1
debug3: tty_make_modes: 54 1
debug3: tty_make_modes: 55 1
debug3: tty_make_modes: 56 0
debug3: tty_make_modes: 57 0
debug3: tty_make_modes: 58 0
debug3: tty_make_modes: 59 1
debug3: tty_make_modes: 60 1
debug3: tty_make_modes: 61 1
debug3: tty_make_modes: 62 0
debug3: tty_make_modes: 70 1
debug3: tty_make_modes: 71 0
debug3: tty_make_modes: 72 1
debug3: tty_make_modes: 73 0
debug3: tty_make_modes: 74 0
debug3: tty_make_modes: 75 0
debug3: tty_make_modes: 90 1
debug3: tty_make_modes: 91 1
debug3: tty_make_modes: 92 0
debug3: tty_make_modes: 93 0
debug1: Sending environment.
debug3: Ignored env MAC
debug3: Ignored env SSH_AGENT_PID
debug3: Ignored env HOSTNAME
debug3: Ignored env SHELL
debug3: Ignored env TERM
debug3: Ignored env DESKTOP_STARTUP_ID
debug3: Ignored env HISTSIZE
debug3: Ignored env SYSADMIN
debug3: Ignored env GTK_RC_FILES
debug3: Ignored env WINDOWID
debug3: Ignored env OLDPWD
debug3: Ignored env USER
debug3: Ignored env LS_COLORS
debug3: Ignored env CLASSES
debug3: Ignored env SSH_AUTH_SOCK
debug3: Ignored env GNOME_KEYRING_SOCKET
debug3: Ignored env USERNAME
debug3: Ignored env AMBER12
debug3: Ignored env SESSION_MANAGER
debug3: Ignored env DESKTOP_SESSION
debug3: Ignored env PATH
debug3: Ignored env MAIL
debug3: Ignored env OWNER
debug3: Ignored env GDM_XSERVER_LOCATION
debug3: Ignored env CUSTODIAN
debug3: Ignored env PWD
debug3: Ignored env INPUTRC
debug3: Ignored env GS_OPTIONS
debug3: Ignored env XMODIFIERS
debug1: Sending env LANG = en_GB.UTF-8
debug2: channel 0: request env confirm 0
debug3: Ignored env GDMSESSION
debug3: Ignored env KRB5CCNAME
debug3: Ignored env SSH_ASKPASS
debug3: Ignored env HOME
debug3: Ignored env SHLVL
debug3: Ignored env GNOME_DESKTOP_SESSION_ID
debug3: Ignored env LOGNAME
debug3: Ignored env CVS_RSH
debug3: Ignored env ISLAPTOP
debug3: Ignored env DBUS_SESSION_BUS_ADDRESS
debug3: Ignored env DEPT
debug3: Ignored env LESSOPEN
debug3: Ignored env ICGROUP
debug3: Ignored env DISPLAY
debug3: Ignored env IP
debug3: Ignored env AMBERHOME
debug3: Ignored env G_BROKEN_FILENAMES
debug3: Ignored env XAUTHORITY
debug3: Ignored env COLORTERM
debug3: Ignored env _
debug2: channel 0: request shell confirm 0
debug2: fd 3 setting TCP_NODELAY
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug2: channel 0: rcvd adjust 2097152

I substituted the ip address and the hostname. If I try with user@hostname, it goes to the password prompt but always tells me that permission is denied.

---------- Post updated at 03:44 PM ---------- Previous update was at 03:20 PM ----------

The output of

ssh -vvv root@hostname

I mean.