Getting “permission denied” with PROFTPD SFTP in C

I want configured a SFTP server with CentOS 6. But when I use "put" with Filezila client, I have this message :

open for write: permission denied

In my logs sftp I Have this when I use 'put':

...
unsupported 'simply@putty.projects.tartarus.org' channel requested, ignoring
'subsystem' channel request for 'sftp' subsystem
..
error checking 'namefile' for REALPATH : Aucun fichier ou dossier de ce type
error opening 'filename'; Permission non accordée

I do not understand because on Debian it works very well...

install Proftpd :

sudo rpm –Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
sudo yum install proftpd

For my tests, I blocked the firewall :

service iptables stop

I commented the line "Subsystem" in ssh configuration file "sshd_config"

# Subsystem sftp ....

I add this lines in proftpd configuration file "proftpd.conf" :

nano /etc/proftpd.conf

LoadModule mod_sftp.c
LoadModule mod_sftp_pam.c

<IfModule mod_sftp.c>
# On écoute sur le port 2222
Port                2222
# On active le mode SFTP
SFTPEngine          on

# Emplacement des clés de cryptage
SFTPHostKey         /etc/ssh/ssh_host_rsa_key2
SFTPHostKey         /etc/ssh/ssh_host_dsa_key2

# Pour le moment, on met authentification par mot de passé
# On changera après par authentification par clé
SFTPAuthMethods     password

# L’utilisateur est bloqué au repertoire qu’on lui a attribué
lors de sa création
DefaultRoot         ~

   # On ajoute les fichiers log pour le sftp
SFTPLog         /etc/sftp/log/sftp.log
TransferLog         /etc/sftp/log/sftp-transfer.log
</IfModule>

I add a new user and new group :

groupadd upload
adduser --home /etc/sftp/home nom_utilisateur
# On associe le nouvel utilisateur à un des groupes (upload ou download)
usermod –g nom_groupe nom_utilisateur

I can connect to SFTP (the log file fills) but I can not use "put".. When I create a file "test" in a server, in filezila the file is rename 'avril 28 12:45 test"..

Permissions of file /home is 777.

This is this proftpd.conf :

# This is the ProFTPD configuration file
ServerName          "ProFTPD server"
ServerIdent         on "FTP Server ready."
ServerAdmin         root@localhost
DefaultServer           on

VRootEngine         on
VRootAlias          /etc/security/pam_env.conf etc/security/pam_env.conf
# Use pam to authenticate (default) and be authoritative
AuthPAMConfig           proftpd
AuthOrder           mod_auth_pam.c* mod_auth_unix.c
# If you use NIS/YP/LDAP you may need to disable PersistentPasswd
PersistentPasswd        off
# Don't do reverse DNS lookups (hangs on DNS problems)
UseReverseDNS           off
# Set the user and group that the server runs as
User               nobody
Group              nobody
# Disable sendfile by default since it breaks displaying the download speeds in
# ftptop and ftpwho
UseSendfile         on
# Define the log formats
LogFormat           default "%h %l %u %t \"%r\" %s %b"
LogFormat           auth    "%v [%P] %h %t \"%r\" %s"
LoadModule mod_sftp.c
LoadModule mod_sftp_pam.c
# Dynamic ban lists (http://www.proftpd.org/docs/contrib/mod_ban.html)
# Enable this with PROFTPD_OPTIONS=-DDYNAMIC_BAN_LISTS in /etc/sysconfig/proftpd
<IfDefine DYNAMIC_BAN_LISTS>
LoadModule            mod_ban.c
BanEngine         on
BanLog            /var/log/proftpd/ban.log
BanTable          /var/run/proftpd/ban.tab
BanOnEvent            MaxLoginAttempts 2/00:10:00 01:00:00
BanControlsACLs       all allow user ftpadm
</IfDefine>
<Global>
# Umask 022 is a good standard umask to prevent new dirs and files
# from being group and world writable
Umask             022
# Allow users to overwrite files and change permissions
AllowOverwrite        on
<Limit ALL SITE_CHMOD>
AllowAll
</Limit>
</Global>

## SFTP
....

回答1:

By default SElinux protect you server and disallow access to directories.

You can allow acces by creating rules using chcon.

Example for a web site :

test the selinux right : ls -dZ /home/myusergrp/myuser/ftp
Allow access right : chcon -R -t httpd_sys_content_t /home/myusergrp/myuser/ftp

Dont remove selinux, prefert go to /etc/selinux/config and configure SELINUX=permissive instead SELINUX=enforcing (and reboot the server). It show you all access problem, that you can solve, and re-enable the enforcing mode after you solve it.

To know more : http://selinuxproject.org/page/FTPRecipes

I hope this help, Mike

回答2:

Solution found! The security service of CentOS restricts access to some directory. So just to disable.

nano  /etc/selinux/config
SELINUX=disabled
#reboot system