Htaccess

htaccess configuration using custom templates

Problem

You want to implement custom restrictions or directives for a web-accessible directory on your SME Server. These might include limiting access to a specified range of IP addresses, enabling the Apache rewrite engine (and specifying rewrite rules), or requiring a password to access a subdirectory of an ibay. The examples on this page assume you want to implement secure authorised access to folders/subfolders in your SME Server ibays. The default settings in SME Server allow you to secure the ibays using the Information Bay panel in server manager, by creating an ibay password which is used to allow authorised access to the ibay from the Internet, but this does not control access to individual folders.

Solution

The use of a .htaccess file and associated password file can control the security of subfolders within ibays by username and password. Htaccess is not enabled by default and .htaccess files are inherently exposed to the Internet and require the correct permissions to be applied to ensure that unauthorised access is not allowed, therefore creating a security risk.

The recommended way to implement .htaccess on a SME server, is to use custom templates, which are only under the control of the administrator and cannot be tampered with by anonymous Internet users. Using this method you do NOT need to install any contrib rpm.

Determining contents of htaccess fragment

This method involves creating a httpd.conf custom template fragment with the required information.

Initially you will need to determine the contents of your .htacess file to be used in the fragment. Refer to the .htaccess web site links below for more details but a basic .htaccess file would contain the following (see specific examples in following sections):

AuthUserFile /etc/passwordfilename
AuthGroupFile /dev/null
AuthName "My Site Security Group"
AuthType Basic
<Limit GET>
order deny,allow
require valid-user
</Limit>

The AuthUserFile will be the location on your sme server of the htaccess password file. You can choose whichever name and location you want, but the password file SHOULD NOT be placed in a publicly accessible area ie NOT in web site folders. Note that this file is created using the htpasswd command (see steps later).

The AuthName can be any name you want.

The rest of the details are basic and can be amended to suit your particular requirements.

	Warning:
	Please choose your AuthUserFile password file name carefully so that it does not correspond with existing filenames. Do not name the file passwd as that filename already exists, and you will overwrite the original system file and make your server inaccessible. Choose a meaningful name like ibaypasswords or similar.

Procedure - authentication against a user password file

Determine the contents of your .htacess file to be used in the fragment, as mentioned previously. The contents shown below will suffice for standard situations.

Custom template creation

Next you need to create the custom template.

Log on to your server command prompt as root or with root privileges and do: (assuming that it does not already exist)

mkdir -p /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf

Create a fragment with a name of your choice

cd /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf
nano -w 50AddSecureIbayFolder

Using the htaccess file contents example from above, and assuming we want to secure an ibay subfolder called /home/e-smith/files/ibays/ibayname/html/foldername/subfoldername

edit the fragment file to contain the following (ensure there is an empty line at the end)

<Directory /home/e-smith/files/ibays/ibayname/html/foldername/subfoldername>
AuthUserFile /etc/passwordfilename
AuthGroupFile /dev/null
AuthName "My Site Security Group"
AuthType Basic
<Limit GET>
order deny,allow
require valid-user
</Limit>
</Directory>

save by ctrl+x

	Note:
	in according with bugzilla:7871 and bugzilla:7890 the following apache modules are loaded by default in the SME8 and also in the future release of SME9. auth_basic authn_file, authz_groupfile there is no longer the requirement to add these by using a custom template 20LoadModule55

Password file creation

Now you need to create the password file, change to the location you want the password file in

cd /etc

then do

htpasswd -c passwordfilename user1

then you will be asked to enter the password

and then asked to confirm the password

The user name and password will be encoded into the password file

To add a second user and password do

htpasswd passwordfilename user2

then you will be asked to enter the password

and then asked to confirm the password

To add a third user and password do

htpasswd passwordfilename user3

then you will be asked to enter the password

and then asked to confirm the password

and so on.

You should only use the -c switch when entering the first user.

If you use the -c switch when entering additional user details you will overwrite the password file completely and only have the one user entry there.

Procedure - authentication against all sme users

Determine the contents of your .htacess file to be used in the fragment, as mentioned previously. The contents shown below will suffice for standard situations.

Custom template creation

mkdir -p /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf
cd /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf
nano -w 50AddSecureIbayFolder

Assuming we want to secure an ibay subfolder called /home/e-smith/files/ibays/ibayname/html/foldername/subfoldername

edit the fragment file to contain the following (ensure there is an empty line at the end)

<Directory /home/e-smith/files/ibays/ibayname/html/foldername/subfoldername>
AuthName "My Site Security Group"
AuthType Basic
AuthExternal pwauth
<Limit GET>
order deny,allow
require valid-user
</Limit>
</Directory>

	Note:
	the "valid-user" setting will allow any valid sme user to gain access

• With SME9 you have to slightly modified the code due to the new authentication authnz_external_module

<Directory /home/e-smith/files/ibays/ibayname/html/foldername/subfoldername>
AuthName "My Site Security Group"
AuthBasicProvider external
AuthType Basic
AuthExternal pwauth
<Limit GET>
order deny,allow
require valid-user
</Limit>
</Directory>

	Note:
	in according with bugzilla:7871 and bugzilla:7890 the following apache modules are loaded by default in the SME8 and also in the future release of SME9. auth_basic authn_file, authz_groupfile there is no longer the requirement to add these by using a custom template 20LoadModule55

Procedure - authentication against specified sme users

Determine the contents of your .htacess file to be used in the fragment, as mentioned previously. The contents shown below will suffice for standard situations.

Custom template creation

mkdir -p /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf
cd /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf
nano -w 50AddSecureIbayFolder

Assuming we want to secure an ibay subfolder called /home/e-smith/files/ibays/ibayname/html/foldername/subfoldername

edit the fragment file to contain the following (ensure there is an empty line at the end)

<Directory /home/e-smith/files/ibays/ibayname/html/foldername/subfoldername>
AuthName "My Site Security Group"
AuthType Basic
AuthExternal pwauth
<Limit GET>
order deny,allow
require user admin smeusername1 smeusername2 smeusername3 smeusername4
</Limit>
</Directory>

	Note:
	where admin, smeusername1, smeusername2 etc are valid users on the sme server

• With SME9 you have to slightly modified the code due to the new authentication authnz_external_module

<Directory /home/e-smith/files/ibays/ibayname/html/foldername/subfoldername>
AuthName "My Site Security Group"
AuthBasicProvider external
AuthType Basic
AuthExternal pwauth
<Limit GET>
order deny,allow
require user admin smeusername1 smeusername2 smeusername3 smeusername4
</Limit>
</Directory>

	Note:
	in according with bugzilla:7871 and bugzilla:7890 the following apache modules are loaded by default in the SME8 and also in the future release of SME9. auth_basic authn_file, authz_groupfile there is no longer the requirement to add these by using a custom template 20LoadModule55

Procedure - authentication against groups

• Unixgroup

You have to download a plugin of pwauth to authenticate unix group in SME Server 8 : http://code.google.com/p/pwauth/ For SME Server 9 a nfr is raised see bugzilla:3690

wget http://pwauth.googlecode.com/files/pwauth-2.3.10.tar.gz
tar xvzf pwauth-2.3.10.tar.gz
cp pwauth-2.3.10/unixgroup /usr/lib/httpd/modules/
chown root:www /usr/lib/httpd/modules/unixgroup
chmod 750 /usr/lib/httpd/modules/unixgroup

We need to create a new fragment

nano /etc/e-smith/templates/etc/httpd/conf/httpd.conf/35-group-auth

{
       $OUT .= "     AddExternalGroup unixgroup /usr/lib/httpd/modules/unixgroup\n";
       $OUT .= "     SetExternalGroupMethod unixgroup environment\n";
}

[root@sme8 ~]# expand-template /etc/httpd/conf/httpd.conf
[root@sme8 ~]# sv t /service/httpd-e-smith
[root@sme8 ~]# sv s /service/httpd-e-smith

After that you are able to check for group membership using following code in .htaccess-Files: (be sure that you are allowed to "AllowOverride AuthConfig" in your directory-rule from apache.

   AuthName "mySite"
   AuthType Basic
   AuthExternal pwauth
   GroupExternal unixgroup
   Require group mygroup
   Satisfy all

mygroup must be a valid group on your server. After that you are able to check for group-membership. Use this syntax if you have several group : group1 group 2 group 3

If you want to allow groups and certain users you can do like this.

   AuthName "mySite"
   AuthType Basic
   AuthExternal pwauth
   GroupExternal unixgroup
   AuthzUserAuthoritative off
   Require group group1 group2 group3
   Require user admin pierre paul
   Satisfy all

• With SME9 you have to slightly modified the code due to the new authentication authnz_external_module

   AuthName "mySite"
   AuthType Basic
   AuthBasicProvider external
   AuthExternal pwauth
   GroupExternal unixgroup
   AuthzUserAuthoritative off
   Require group group1 group2 group3
   Require user admin pierre paul
   Satisfy all

• Forum's references

Two methods are outlined in this forum post

http://forums.contribs.org/index.php/topic,38959.msg177967.html#msg177967

One method solves this by expanding the group to all members in it and adding them to the required user directive, see

http://forums.contribs.org/index.php/topic,38959.msg177464.html#msg177464

The other method solves this by using the unixgroup check script, see

http://forums.contribs.org/index.php/topic,38959.msg177967.html#msg177967

Testing

Now you can test the web site access.

Ensure you have created the actual web site folder or subfolder, and then browse to your newly secured location ie

www./yourdomain.com/ibayname/foldername/subfoldername

You will be asked for a user Id and password.

Enter any combination that is allowed by your configuration to gain access, ie is in your password file, is any sme user, or is a specfied sme user.

Deletion procedure

To undo any changes you make using this method, do the following, replacing filenames with those actually used

rm /etc/passwordfilename
rm /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf/50AddSecureIbayFolder
rm /etc/e-smith/templates/etc/httpd/conf/httpd.conf/35-group-auth 
expand-template /etc/httpd/conf/httpd.conf
sv t /service/httpd-e-smith
sv s /service/httpd-e-smith

Additional Information

See these resources for further information about creating and using htaccess although much of that information is not applicable to the method outlined in this HOWTO.

It will assist you to determine the contents of the htaccess file that will be placed into the custom template fragment.

http://www.freewebmasterhelp.com/tutorials/htaccess/

http://www.its.queensu.ca/network/policy/htaccess.shtml

http://www.washington.edu/computing/web/publishing/htaccess.html

http://www.htmlite.com/HTA003.php

http://www.cs.hmc.edu/qref/web/htaccess.html

For further information about custom templates see:

http://wiki.contribs.org/SME_Server:Documentation:Developers_Manual

Other References:

http://forums.contribs.org/index.php?topic=42190.0

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