Dotaz: scponly v chrootu

[pele]

Zdravim, pred nedavnem jsem se pokousel robehat scponly v chrootu v debianu, vse dopadlo vyborne az na jedu vec, kterou zminim v zveru.

Nyni sem se vsak dostal k Ubuntu a trochu sem se zaseknul. Normalne scp nainstaluju. Popisi postup:

apt-get install scponly
dpkg-reconfigure -plow scponly

zvolim "Yes".

cd /usr/share/doc/scponly/setup_chroot
sudo gunzip setup_chroot.sh.gz
sudo chmod +x setup_chroot.sh
sudo ./setup_chroot.sh

Vytvorim tim noveho uzivatele, dejme tomu sftpuser.

mkdir /home/sftpuser/dev 
mknod -m 666 /home/sftpuser/dev/null c 1 3

Provedu drobnou upravu v /etc/passwd, asi nejak takhle:

sftpguest:x:1001:1001::/home/sftpguest//incoming:/usr/sbin/scponlyc

A melo by to jet. Ale pokud se pokusim prihlasit:

 sftp -vvv sftpuser@host
Connecting to host...
OpenSSH_4.6p1 Debian-5, OpenSSL 0.9.8e 23 Feb 2007
debug1: Reading configuration data /home/tom/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to kompik [10.0.0.139] port 22.
debug1: Connection established.
debug1: identity file /home/tom/.ssh/id_rsa type 1
debug1: identity file /home/tom/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3p2 Debian-8ubuntu1
debug1: match: OpenSSH_4.3p2 Debian-8ubuntu1 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.6p1 Debian-5
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: kex: client->server aes128-cbc hmac-md5 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: Host 'host' is known and matches the RSA host key.
debug1: Found key in /home/tom/.ssh/known_hosts:1
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received

*****************************************************************
*This is a private SSH service. You are not supposed to be here.*
*Please leave immediately.                                      *
*****************************************************************
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering public key: /home/tom/.ssh/id_rsa
debug1: Authentications that can continue: publickey,password
debug1: Trying private key: /home/tom/.ssh/id_dsa
debug1: Next authentication method: password
sftpuser@host's password: 
debug1: Authentications that can continue: publickey,password
Permission denied, please try again.

Heslo zadavam zcela jiste spravne, zkousel sem i zmenit. Pokud se prihlasim lokalne pres su vse funguje, tedy v ramci scponly shellu.

Druhou veci, kterou jsem slibil zminit na zacatku je skutecnost ktera me pomerne zarazila. Pripojim-li se (k fungujicimu scponly) pres sftp chroot funguje tak jak ma, ale pokud pouziji treba gftp pak se dostanu ven chrootu, je to mozne? Stava se Vam to take?

Dekuji za odpovedi a preju hezky svatecni den.

Odpovědi

[juzna]

Mam na kubuntu podobny problem. Nenapise mi to Permission denied, ale stejnak to spojeni hnedka skonci.

Vypis logu po zadani hesla:

pepik@juzna.cz's password:
debug1: Authentication succeeded (password).
debug1: channel 0: new [client-session]
debug1: Entering interactive session.
debug1: Sending environment.
debug1: Sending env LANG = en_US.UTF-8
debug1: Sending subsystem: sftp
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug1: channel 0: free: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: Transferred: stdin 0, stdout 0, stderr 0 bytes in 0.1 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0
debug1: Exit status 1
Connection closed

Je tu nekdo, komu to chodit?

[juzna]

Haha klasika, jako vzdycky.

Dva dny resim problem a az uz projdu cely internet a vsecko prectu, a furt mi to nejde, tak se zeptam. A v zapeti to vyresim :o)

Takze vysledek: v (k)ubuntu nema scponlyc nastaven setuid bit, takze to musite nastavit explicitne: chmod u+s /usr/sbin/scponlyc

A pak uz to jde.

Na puvodni dotaz ale fakt nevim :(

[panko]

mal som uplne rovnaky problem a podla logu som tiez neprisiel na riesenie, ale niekde na forach som vyhrabal, ze shell

scponlyc

potrebuje

/dev/null

v chroot prostredi, takze v chroot adresari staci

mkdir dev

touch dev/null

a

chmod 666 dev/null

a malo by to fungovat, v mojom pripade to pomohlo

[zelial]

jen malé doplnění: takto vytvořený dev null nebude mít vlastnosti pravého nullu - nebudou se v něm nenávratně ztrácet data. takže bude narůstat a půjde z nej číst, což představuje riziko.

radši zkopíruj opravdový /dev/null nebo si vytvoř nový (/sbin/MKDEV null)