Apache Module mod_auth_pgsql

PostgreSQL Authentication 

• Authentication

	One database, and one (or two) tables.  One table holds the username and the encryped (or plain) password.
 	The other table holds the username and the names of the group to which the user belongs.  
	It is possible to have username, groupname and password in the same table. 

• Access Logging

	Every authentication access is logged in the same database of the authentication table, but in different table.
	User name and date of the request are logged.
	As option, it can log password, ip address, request line.

This page documents version 0.9.12 (2002 01 11) of mod_auth_pgsql require Apache >= 1.3.9 (tested up to 1.3.20)  and PostreSQL >=  7.x 

Module Directives | Download | Compilation & Installation Notes | Example | Technical Notes | Changelog

Directives

• Auth_PG_host
• Auth_PG_port
• Auth_PG_options
• Auth_PG_database
• Auth_PG_user
• Auth_PG_pwd
• Auth_PG_pwd_table
• Auth_PG_grp_table
• Auth_PG_uid_field
• Auth_PG_pwd_field
• Auth_PG_gid_field
• Auth_PG_nopasswd
• Auth_PG_authoritative
• Auth_PG_lowercase_uid
• Auth_PG_uppercase_uid
• Auth_PG_pwd_ignore_case
  
• Auth_PG_encrypted
• Auth_PG_hash_type
  
• Auth_PG_pwd_whereclause
• Auth_PG_grp_whereclause
• Auth_PG_cache_passwords
  
• Auth_PG_log_table
• Auth_PG_log_uname_field
• Auth_PG_log_date_field
• Auth_PG_log_uri_field
• Auth_PG_log_addrs_field
• Auth_PG_log_pwd_field

Auth_PG_host

Specifies the host on which the postmaster is running. The effective uid of the server should be allowed access, otherwise a trusted user or user with password must be specified.

Auth_PG_port

Specifies the TCP/IP port number at which the postmaster can be found.

Auth_PG_options

Specifies an option string to be passed to the postgreSQL backend process. Refer to the PostgreSQL user manual for a description of the available options.

Auth_PG_database

Specifies the name of the database that stores the authentication information.

Auth_PG_user

Auth_PG_pwd

Syntax: Auth_PG_pwd password
Context: directory, .htaccess
Override: AuthConfig
Status: Extension

Specifies the user password for the user who access the PostgreSQL.
Needed if the user specified with Auth_PG_user is not trusted.

Auth_PG_pwd_table

Gives the name of the relation which contains the username and password information.
See Auth_PG_encrypted, by default the password is encrypted.

Auth_PG_grp_table

Gives the name of the relation which contains the username and group information. This can be the same table specified with Auth_PG_pwd_table. This directive is only necessary if you want to authenticate by user groups. A user within multiple groups has therefore multiple entries.

Auth_PG_uid_field

Specifies the attribute name of the field containing the user name in the Auth_PG_pwd_table relation.

Auth_PG_pwd_field

Specifies the attribute name of the field containing the encrypted (see Auth_PG_encrypted) password in the Auth_PGpwd_table relation.

Auth_PG_gid_field

Specifies the attribute name of the field containing the group name in the Auth_PG_grp_table relation. This directive is only necessary if you want to authenticate by user groups.

Auth_PG_nopasswd

This option is off by default. Turning it on will cause a user to be validated when their password field is empty. The password entered will be ignored. Exercise caution when turning this on.

Auth_PG_authoritative

This option is on by default. Turning it off will cause low level errors such a user not being found or a simple configuration error to fall through to other authentication directives which may be defined for this area. For example, if a parent directory has another authorization scheme and a user name is not found for the PostgreSQL scheme, the parent directory scheme will be given the chance to try and authenticate the user. Exercise caution when turning this option off. It can be a security risk. Can be used to use two authentication schemes for the same dir.

Auth_PG_lowercase_uid

This option is off by default. Controls whether this module converts user UIDs to lowercase before looking them up. When turned on this does not affect the case of the original user ID should this module decline to authenticate and a lower level is called.

Auth_PG_uppercase_uid

This option is off by default. Controls whether this module converts user UIDs to uppercase before looking them up. When turned on this does not affect the case of the original user ID should this module decline to authenticate and a lower level is called.

Auth_PG_pwd_ignore_case

This option is off by default. Controls whether this module ignore the upper/lowercase of password from user, when looking up clear text password from db. 

Auth_PG_encrypted

Defaults to on. Controls weather this module expects passwords in the database to be encrypted or not. When turned off, you can use unencrypted passwords in your database. Exercise caution when deciding to turn this off!

Auth_PG_hash_type

Set the encryption type for the password stored in the database.
Defaults to CRYPT. 

Auth_PG_pwd_whereclause

This option allows you to exercise greater control over the SQL code used to retrieve the user name and password from the database. You can use this to search for the username using more attributes in the table than the pwd_field.

The basic SQL statement used to retrieve a user's password for checking looks like this:

select <pwd_field> from <pwd_table> where <uid_field> ='<remote_user> '

The pwd_whereclause will be added to the end of this statement and must fit logically. The where clause must be double quoted, with initial space .

Example:

      Auth_PG_pwd_whereclause " and access_level > 100 "

Auth_PG_grp_whereclause

This option allows you to exercise greater control over the SQL code used to retrieve the group name and corresponding user from the database. You can use this to search for the group name using more attributes in the table than the gid_field.

The basic SQL statement used to retrieve a group name and user name for checking looks like this:

select <uid_field> from <grp_table> where <gid_field> ='<required group> '

Auth_PG_cache_passwords

Auth_PG_log_table

Auth_PG_log_uname_field

Auth_PG_log_date_field

Auth_PG_log_uri_field

Auth_PG_log_addrs_field

Auth_PG_log_pwd_field

Example

PostgreSQL trusted user:

	AuthName "My PostgreSQL Authenticator"
	AuthType basic

	Auth_PG_host localhost
	Auth_PG_port 5432
	Auth_PG_user postgres
	Auth_PG_database www
	Auth_PG_pwd_table valid_users
	Auth_PG_uid_field user
	Auth_PG_pwd_field password

	<LIMIT GET POST>
		require valid-user
	</LIMIT>

PostgreSQL trusted user, select only users with access_level > 100:

	AuthName "My PostgreSQL Authenticator"
	AuthType basic

	Auth_PG_host localhost
	Auth_PG_port 5432
	Auth_PG_user postgres
	Auth_PG_database www
	Auth_PG_pwd_table valid_users
	Auth_PG_uid_field user
	Auth_PG_pwd_field password
        Auth_PG_pwd_whereclause " and access_level > 100 "

	<LIMIT GET POST>
		require valid-user
	</LIMIT>

PostgreSQL user with password authentication, with logging:

	AuthName "My PostgreSQL Authenticator"
	AuthType basic

	Auth_PG_host someserver.somenet
	Auth_PG_port 5432
	Auth_PG_user postgres
	Auth_PG_pwd xxxxxxx
	Auth_PG_database www
	Auth_PG_pwd_table valid_users
	Auth_PG_uid_field user
	Auth_PG_pwd_field password
	Auth_PG_log_table access_log
	Auth_PG_log_uname_field login
	Auth_PG_log_date_field date
	Auth_PG_log_uri_field 	request
	Auth_PG_log_addrs_field  ip_address


	<LIMIT GET POST>
		require valid-user
	</LIMIT>

Technical Notes

• If the SQL statement used to retrieve the user or group name returns more than one tuple, it is considered an error. If this is likely to happen, use Auth_PG_pwd_whereclause and Auth_PG_grp_whereclause to create a query that will only return one tuple.
  

Download 

• Latest release:
  http://www.giuseppetanzilli.it /mod_auth_pgsql/dist/
• Homepage and Documentation:
  http://www.giuseppetanzilli.it/mod_auth_pgsql

Compilation & Installation Notes

APACI STATIC Install
	- untar apache source and run ./configure from the apache source dir
		cd /usr/local/src
		tar zxf apache_1.3.X.tar.gz
		cd apache_1.3.X
		./configure

	- untar mod_auth_pgsql  and configure from the module dir:
		cd /usr/local/src
		tar zxf mod_auth_pgsql-X.Y.Z.tar.gz
		cd mod_auth_pgsql-X.Y.Z
		./configure --with-apache=/usr/local/src/apache_1.3.X --with-pgsql=/usr/local/pgsql
		   
		   NOTE: 	--with-apache point to apache source tree   
		   			--with-pgsql specify where pgsql was installed
	- make & install	   
		make
		make install
		
	- run the apache configure with  "--activate-module=src/modules/auth_pgsql/mod_auth_pgsql.c" 
		cd /usr/local/src/apache_1.3.X
		./configure --activate-module=src/modules/auth_pgsql/mod_auth_pgsql.c
	- run the apache make & install
		make
		make install

APXS DSO Install:
	- untar apache source and run ./configure and install
		cd /usr/local/src
		tar zxf apache_1.3.X.tar.gz
		cd apache_1.3.X
		./configure -enable-module=so
		make 
		make install

	- untar mod_auth_pgsql  and configure from the module dir:
		cd /usr/local/src
		tar zxf mod_auth_pgsql-X.Y.Z.tar.gz
		cd mod_auth_pgsql-X.Y.Z
		./configure --with-apxs=/usr/local/apache/bin/apxs --with-pgsql=/usr/local/pgsql
			NOTE: --with-apxs is the apache installation tree (not source)

	- edit /usr/local/apache/bin/apxs and change these two rows:
		FROM:
			my $CFG_LD_SHLIB      = q();          # substituted via Makefile.tmpl
			my $CFG_LDFLAGS_SHLIB = q(); # substituted via Makefile.tmpl
		TO:
			my $CFG_LD_SHLIB      = q(ld);          # substituted via Makefile.tmpl
			my $CFG_LDFLAGS_SHLIB = q(-G); # substituted via Makefile.tmpl
	
	- compile the module 	 
		/usr/local/apache/bin/apxs \
        	-I/usr/local/pgsql/include \
        	-L/usr/local/pgsql/lib -lpq \
        	-o mod_auth_pgsql.so -c mod_auth_pgsql.c auth_pgsql_shared_stub.c
	- install the module
		/usr/local/apache/bin/apxs -i -a -n auth_pgsql mod_auth_pgsql.so

Changelog