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Authentication improvements:

Browse Source 
A new pg_hba.conf column, USER
Allow specifiction of lists of users separated by commas
Allow group names specified by +
Allow include files containing lists of users specified by @
Allow lists of databases, and database files
Allow samegroup in database column to match group name matching dbname
Removal of secondary password files
Remove pg_passwd utility
Lots of code cleanup in user.c and hba.c
New data/global/pg_pwd format
New data/global/pg_group file
This commit is contained in:
Bruce Momjian
2002-04-04 04:25:54 +00:00
parent af10378ab0
commit 43a3543a4e
25 changed files with 1453 additions and 1931 deletions
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605
doc/src/sgml/client-auth.sgml
View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/client-auth.sgml,v 1.33 2002/03/22 19:20:06 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/client-auth.sgml,v 1.34 2002/04/04 04:25:44 momjian Exp $
-->
<chapter id="client-authentication">
@ -10,14 +10,13 @@ $Header: /cvsroot/pgsql/doc/src/sgml/client-auth.sgml,v 1.33 2002/03/22 19:20:06
</indexterm>
<para>
When a client application connects to the database server, it specifies which
<productname>PostgreSQL</productname> user name it wants to connect as,
much the same way one logs into a Unix computer as a particular user.
Within the SQL environment the active
database user name determines access privileges to database
objects -- see <xref linkend="user-manag"> for more information
about that. It is therefore obviously essential to restrict which
database user name(s) a given client can connect as.
When a client application connects to the database server, it
specifies which <productname>PostgreSQL</productname> user name it
wants to connect as, much the same way one logs into a Unix computer
as a particular user. Within the SQL environment the active database
user name determines access privileges to database objects -- see
<xref linkend="user-manag"> for more information. Therefore, it is
essential to restrict which database users can connect.
</para>
<para>
@ -30,20 +29,19 @@ $Header: /cvsroot/pgsql/doc/src/sgml/client-auth.sgml,v 1.33 2002/03/22 19:20:06
<para>
<productname>PostgreSQL</productname> offers a number of different
client authentication methods. The method to be used can be selected
on the basis of (client) host and database; some authentication methods
allow you to restrict by user name as well.
client authentication methods. The method to be used can be selected
on the basis of (client) host, database, and user.
</para>
<para>
<productname>PostgreSQL</productname> database user names are logically
<productname>PostgreSQL</productname> user names are logically
separate from user names of the operating system in which the server
runs. If all the users of a particular server also have accounts on
runs. If all the users of a particular server also have accounts on
the server's machine, it makes sense to assign database user names
that match their operating system user names. However, a server that accepts remote
connections may have many users who have no local account, and in such
cases there need be no connection between database user names and OS
user names.
that match their operating system user names. However, a server that
accepts remote connections may have many users who have no local
account, and in such cases there need be no connection between
database user names and OS user names.
</para>
<sect1 id="pg-hba-conf">
@ -56,39 +54,39 @@ $Header: /cvsroot/pgsql/doc/src/sgml/client-auth.sgml,v 1.33 2002/03/22 19:20:06
<para>
Client authentication is controlled by the file
<filename>pg_hba.conf</filename> in the data directory, e.g.,
<filename>/usr/local/pgsql/data/pg_hba.conf</filename>. (<acronym>HBA</> stands
for host-based authentication.) A default <filename>pg_hba.conf</filename>
file is installed when the
data area is initialized by <command>initdb</command>.
<filename>/usr/local/pgsql/data/pg_hba.conf</filename>.
(<acronym>HBA</> stands for host-based authentication.) A default
<filename>pg_hba.conf</filename> file is installed when the data area
is initialized by <command>initdb</command>.
</para>
<para>
The general format of the <filename>pg_hba.conf</filename> file is
of a set of records, one per line. Blank lines and lines beginning
with a hash character (<quote>#</quote>) are ignored. A record is
made up of a number of fields which are separated by spaces and/or
tabs. Records cannot be continued across lines.
The general format of the <filename>pg_hba.conf</filename> file is of
a set of records, one per line. Blank lines are ignored, as is any
text after the <quote>#</quote> comment character. A record is made
up of a number of fields which are separated by spaces and/or tabs.
Fields can contain white space if the field value is quoted. Records
cannot be continued across lines.
</para>
<para>
Each record specifies a connection type, a client IP address range
(if relevant for the connection type), a database name or names,
(if relevant for the connection type), a database name, a user name,
and the authentication method to be used for connections matching
these parameters.
The first record that matches the type, client address, and requested
database name of a connection attempt is used to do the
authentication step. There is no <quote>fall-through</> or
these parameters. The first record with a matching connection type,
client address, requested database, and user name is used to perform
authentication. There is no <quote>fall-through</> or
<quote>backup</>: if one record is chosen and the authentication
fails, the following records are not considered. If no record
matches, the access will be denied.
fails, subsequent records are not considered. If no record matches,
access is denied.
</para>
<para>
A record may have one of the three formats
<synopsis>
local <replaceable>database</replaceable> <replaceable>authentication-method</replaceable> [ <replaceable>authentication-option</replaceable> ]
host <replaceable>database</replaceable> <replaceable>IP-address</replaceable> <replaceable>IP-mask</replaceable> <replaceable>authentication-method</replaceable> [ <replaceable>authentication-option</replaceable> ]
hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable> <replaceable>IP-mask</replaceable> <replaceable>authentication-method</replaceable> [ <replaceable>authentication-option</replaceable> ]
local <replaceable>database</replaceable> <replaceable>user</replaceable> <replaceable>authentication-method</replaceable> [ <replaceable>authentication-option</replaceable> ]
host <replaceable>database</replaceable> <replaceable>user</replaceable> <replaceable>IP-address</replaceable> <replaceable>IP-mask</replaceable> <replaceable>authentication-method</replaceable>
hostssl <replaceable>database</replaceable> <replaceable>user</replaceable> <replaceable>IP-address</replaceable> <replaceable>IP-mask</replaceable> <replaceable>authentication-method</replaceable>
</synopsis>
The meaning of the fields is as follows:
@ -97,7 +95,7 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><literal>local</literal></term>
<listitem>
<para>
This record pertains to connection attempts over Unix domain
This record applies to connection attempts using Unix domain
sockets.
</para>
</listitem>
@ -107,10 +105,11 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><literal>host</literal></term>
<listitem>
<para>
This record pertains to connection attempts over TCP/IP
networks. Note that TCP/IP connections are completely disabled
unless the server is started with the <option>-i</option> switch or
the equivalent configuration parameter is set.
This record applied to connection attempts using TCP/IP networks.
Note that TCP/IP connections are disabled unless the server is
started with the <option>-i</option> option or the
<literal>tcpip_socket</> <filename>postgresql.conf</>
configuration parameter is enabled.
</para>
</listitem>
</varlistentry>
@ -119,13 +118,13 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><literal>hostssl</literal></term>
<listitem>
<para>
This record pertains to connection attempts with SSL over
This record applies to connection attempts using SSL over
TCP/IP. To make use of this option the server must be
built with SSL support enabled. Furthermore, SSL must be
enabled with the <option>-l</> option or equivalent configuration
setting when the server is started. (Note: <literal>host</literal>
records will match either SSL or non-SSL connection attempts, but
<literal>hostssl</literal> records match only SSL connections.)
<literal>hostssl</literal> records requires SSL connections.)
</para>
</listitem>
</varlistentry>
@ -134,12 +133,35 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><replaceable>database</replaceable></term>
<listitem>
<para>
Specifies the database that this record applies to. The value
Specifies the database for this record. The value
<literal>all</literal> specifies that it applies to all
databases, while the value <literal>sameuser</> identifies the
database with the same name as the connecting user. Otherwise,
this is the name of a specific <productname>PostgreSQL</productname>
database.
database with the same name as the connecting user. The value
<literal>samegroup</> identifies a group with the same name as
the database name. Only members of this group can connect to the
database. Otherwise, this is the name of a specific
<productname>PostgreSQL</productname> database. Multiple database
names can be supplied by separating them with commas. A file
containing database names can be specified by preceding the file
name with <literal>@</>. The file must be in the same directory
as <filename>pg_hba.conf</>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>user</replaceable></term>
<listitem>
<para>
Specifies the user for this record. The value
<literal>all</literal> specifies that it applies to all users.
Otherwise, this is the name of a specific
<productname>PostgreSQL</productname> user. Multiple user names
can be supplied by separating them with commas. Group names can
be specified by preceding the group name with <literal>+</>. A
file containing user names can be specified by preceding the file
name with <literal>@</>. The file must be in the same directory
as <filename>pg_hba.conf</>.
</para>
</listitem>
</varlistentry>
@ -149,10 +171,9 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><replaceable>IP mask</replaceable></term>
<listitem>
<para>
These two fields specify to which client machines a
<literal>host</literal> or <literal>hostssl</literal>
record applies, based on their IP
address. (Of course IP addresses can be spoofed but this
These two fields specify the client machine IP addresses
(<literal>host</literal> or <literal>hostssl</literal>) for this
record. (Of course IP addresses can be spoofed but this
consideration is beyond the scope of
<productname>PostgreSQL</productname>.) The precise logic is that
<blockquote>
@ -169,10 +190,9 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><replaceable>authentication method</replaceable></term>
<listitem>
<para>
Specifies the method that users must use to authenticate themselves
when connecting under the control of this authentication record.
The possible choices are summarized here,
details are in <xref linkend="auth-methods">.
Specifies the authentication method to use when connecting via
this record. The possible choices are summarized here; details
are in <xref linkend="auth-methods">.
<variablelist>
<varlistentry>
@ -190,31 +210,8 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><literal>reject</></term>
<listitem>
<para>
The connection is rejected unconditionally. This is mostly
useful to <quote>filter out</> certain hosts from a group.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>password</></term>
<listitem>
<para>
The client is required to supply a password which is required to
match the database password that was set up for the user.
</para>
<para>
An optional file name may be specified after the
<literal>password</literal> keyword. This file is expected to
contain a list of users who may connect using this record,
and optionally alternative passwords for them.
</para>
<para>
The password is sent over the wire in clear text. For better
protection, use the <literal>md5</literal> or
<literal>crypt</literal> methods.
The connection is rejected unconditionally. This is useful for
<quote>filtering out</> certain hosts from a group.
</para>
</listitem>
</varlistentry>
@ -223,17 +220,9 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><literal>md5</></term>
<listitem>
<para>
Like the <literal>password</literal> method, but the password
is sent over the wire encrypted using a simple
challenge-response protocol. This protects against incidental
wire-sniffing. This is now the recommended choice for
password-based authentication.
</para>
<para>
The name of a file may follow the
<literal>md5</literal> keyword. It contains a list of users
who may connect using this record.
Requires the client to supply an MD5 encrypted password for
authentication. This is the only method that allows encrypted
passwords to be stored in pg_shadow.
</para>
</listitem>
</varlistentry>
@ -242,14 +231,20 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><literal>crypt</></term>
<listitem>
<para>
Like the <literal>md5</literal> method but uses older crypt
encryption, which is needed for pre-7.2
clients. <literal>md5</literal> is
preferred for 7.2 and later clients. The <literal>crypt</>
method is not compatible with encrypting passwords in
<filename>pg_shadow</>, and may fail if client and server
machines have different implementations of the crypt() library
routine.
Like <literal>md5</literal> method but uses older crypt
encryption, which is needed for pre-7.2 clients.
<literal>md5</literal> is preferred for 7.2 and later clients.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>password</></term>
<listitem>
<para>
Same as "md5", but the password is sent in cleartext over the
network. This should not be used on untrusted networks.
</para>
</para>
</listitem>
</varlistentry>
@ -278,34 +273,36 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<term><literal>ident</></term>
<listitem>
<para>
The identity of the user as determined on login to the
operating system is used by <productname>PostgreSQL</productname>
to determine whether the user
is allowed to connect as the requested database user.
For TCP/IP connections the user's identity is determined by
contacting the <firstterm>ident</firstterm> server on the client
host. (Note that this is only as reliable as the remote ident
server; ident authentication should never be used for remote hosts
whose administrators are not trustworthy.)
On operating systems
supporting <symbol>SO_PEERCRED</> requests for Unix domain sockets,
ident authentication is possible for local connections;
the system is then asked for the connecting user's identity.
For TCP/IP connections, authentication is done by contacting
the <firstterm>ident</firstterm> server on the client host.
This is only as secure as the client machine. You must specify
the map name after the 'ident' keyword. It determines how to
map remote user names to PostgreSQL user names. If you use
"sameuser", the user names are assumed to be identical. If
not, the map name is looked up in the $PGDATA/pg_ident.conf
file. The connection is accepted if that file contains an
entry for this map name with the ident-supplied user name and
the requested PostgreSQL user name.
</para>
<para>
On machines that support unix-domain socket credentials
(currently Linux, FreeBSD, NetBSD, and BSD/OS), ident allows
reliable authentication of 'local' connections without ident
running on the local machine.
</para>
<para>
On systems without <symbol>SO_PEERCRED</> requests, ident
authentication is only available for TCP/IP connections. As a
work around, it is possible to specify the <systemitem
class="systemname">localhost</> address <systemitem
class="systemname">127.0.0.1</> and make connections to this
address.
</para>
<para>
On systems without <symbol>SO_PEERCRED</> requests, ident authentication
is only available for TCP/IP connections. As a workaround,
it is possible to
specify the <systemitem class="systemname">localhost</> address
<systemitem class="systemname">127.0.0.1</> and make connections
to this address.
</para>
<para>
The <replaceable>authentication option</replaceable> following
the <literal>ident</> keyword specifies the name of an
<firstterm>ident map</firstterm> that specifies which operating
system users equate with which database users. See below for
details.
Following the <literal>ident</> keyword, an <firstterm>ident
map</firstterm> name should be supplied which specifies which
operating system users equate with which database users. See
below for details.
</para>
</listitem>
</varlistentry>
@ -315,17 +312,16 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<listitem>
<para>
This authentication type operates similarly to
<firstterm>password</firstterm>, with the main difference that
it will use PAM (Pluggable Authentication Modules) as the
authentication mechanism. The <replaceable>authentication
option</replaceable> following the <literal>pam</> keyword
specifies the service name that will be passed to PAM. The
default service name is <literal>postgresql</literal>.
For more information about PAM, please read the <ulink
url="http://www.kernel.org/pub/linux/libs/pam/"><productname>Linux-PAM</productname>
Page</ulink> and/or the <ulink
url="http://www.sun.com/software/solaris/pam/"><systemitem class="osname">Solaris</> PAM
Page</ulink>.
<firstterm>password</firstterm> except that it uses PAM
(Pluggable Authentication Modules) as the authentication
mechanism. The default PAM service name is
<literal>postgresql</literal>. You can optionally supply you
own service name after the <literal>pam</> keyword in the
file. For more information about PAM, please read the <ulink
url="http://www.kernel.org/pub/linux/libs/pam/"><productname>L
inux-PAM</productname> Page</ulink> and the <ulink
url="http://www.sun.com/software/solaris/pam/"><systemitem
class="osname">Solaris</> PAM Page</ulink>.
</para>
</listitem>
</varlistentry>
@ -336,42 +332,33 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>authentication option</replaceable></term>
<listitem>
<para>
This field is interpreted differently depending on the
authentication method, as described above.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
<para>
Since the <filename>pg_hba.conf</filename> records are examined
sequentially for each connection attempt, the order of the records is
very significant. Typically, earlier records will have tight
connection match parameters and weaker authentication methods,
while later records will have looser match parameters and stronger
authentication methods. For example, one might wish to use
<literal>trust</> authentication for local TCP connections but
require a password for remote TCP connections. In this case a
record specifying <literal>trust</> authentication for connections
from 127.0.0.1 would appear before a record specifying password
authentication for a wider range of allowed client IP addresses.
significant. Typically, earlier records will have tight connection
match parameters and weaker authentication methods, while later
records will have looser match parameters and stronger authentication
methods. For example, one might wish to use <literal>trust</>
authentication for local TCP connections but require a password for
remote TCP connections. In this case a record specifying
<literal>trust</> authentication for connections from 127.0.0.1 would
appear before a record specifying password authentication for a wider
range of allowed client IP addresses.
</para>
<para>
<indexterm>
<primary>SIGHUP</primary>
</indexterm>
The <filename>pg_hba.conf</filename> file is read on start-up
and when the <application>postmaster</> receives a
The <filename>pg_hba.conf</filename> file is read on start-up and when
the <application>postmaster</> receives a
<systemitem>SIGHUP</systemitem> signal. If you edit the file on an
active system, you will need to signal the <application>postmaster</>
(using <literal>pg_ctl reload</> or <literal>kill -HUP</>)
to make it re-read the file.
(using <literal>pg_ctl reload</> or <literal>kill -HUP</>) to make it
re-read the file.
</para>
<para>
@ -382,27 +369,27 @@ hostssl <replaceable>database</replaceable> <replaceable>IP-address</replaceable
<example id="example-pg-hba.conf">
<title>An example <filename>pg_hba.conf</filename> file</title>
<programlisting>
# TYPE DATABASE IP_ADDRESS MASK AUTHTYPE MAP
# TYPE DATABASE USER IP_ADDRESS MASK AUTHTYPE
# Allow any user on the local system to connect to any
# database under any username, but only via an IP connection:
# database under any user name, but only via an IP connection:
host all 127.0.0.1 255.255.255.255 trust
host all all 127.0.0.1 255.255.255.255 trust
# The same, over Unix-socket connections:
local all trust
local all all trust
# Allow any user from any host with IP address 192.168.93.x to
# connect to database "template1" as the same username that ident on that
# host identifies him as (typically his Unix username):
# connect to database "template1" as the same user name that ident on that
# host identifies him as (typically his Unix user name):
host template1 192.168.93.0 255.255.255.0 ident sameuser
host template1 all 192.168.93.0 255.255.255.0 ident sameuser
# Allow a user from host 192.168.12.10 to connect to database "template1"
# if the user's password in pg_shadow is correctly supplied:
# if the user's password is correctly supplied:
host template1 192.168.12.10 255.255.255.255 md5
host template1 all 192.168.12.10 255.255.255.255 md5
# In the absence of preceding "host" lines, these two lines will reject
# all connection attempts from 192.168.54.1 (since that entry will be
@ -410,8 +397,8 @@ host template1 192.168.12.10 255.255.255.255 md5
# else on the Internet. The zero mask means that no bits of the host IP
# address are considered, so it matches any host:
host all 192.168.54.1 255.255.255.255 reject
host all 0.0.0.0 0.0.0.0 krb5
host all all 192.168.54.1 255.255.255.255 reject
host all all 0.0.0.0 0.0.0.0 krb5
# Allow users from 192.168.x.x hosts to connect to any database, if they
# pass the ident check. If, for example, ident says the user is "bryanh"
@ -419,7 +406,7 @@ host all 0.0.0.0 0.0.0.0 krb5
# is allowed if there is an entry in pg_ident.conf for map "omicron" that
# says "bryanh" is allowed to connect as "guest1":
host all 192.168.0.0 255.255.0.0 ident omicron
host all all 192.168.0.0 255.255.0.0 ident omicron
# If these are the only two lines for local connections, they will allow
# local users to connect only to their own databases (database named the
@ -429,8 +416,8 @@ host all 192.168.0.0 255.255.0.0 ident omicron
# cases. (If you prefer to use ident authorization, an ident map can
# serve a parallel purpose to the password list file used here.)
local sameuser md5
local all md5 admins
local sameuser all md5
local all @admins md5
</programlisting>
</example>
</para>
@ -490,86 +477,49 @@ local all md5 admins
<title>Password authentication</title>
<indexterm>
<primary>password</primary>
<primary>MD5</>
</indexterm>
<indexterm>
<primary>MD5</>
<primary>crypt</>
</indexterm>
<indexterm>
<primary>password</primary>
</indexterm>
<para>
Password-based authentication methods include <literal>md5</>,
<literal>crypt</>, and <literal>password</>. These methods operate
<literal>crypt</>, and <literal>password</>. These methods operate
similarly except for the way that the password is sent across the
connection. If you are at all concerned about password <quote>sniffing</>
attacks then <literal>md5</> is preferred, with <literal>crypt</> a
second choice if you must support obsolete clients. Plain
<literal>password</> should especially be avoided for connections over
the open Internet (unless you use SSL, SSH, or other communications
security wrappers around the connection).
connection. If you are at all concerned about password
<quote>sniffing</> attacks then <literal>md5</> is preferred, with
<literal>crypt</> a second choice if you must support pre-7.2
clients. Plain <literal>password</> should especially be avoided for
connections over the open Internet (unless you use SSL, SSH, or
other communications security wrappers around the connection).
</para>
<para>
<productname>PostgreSQL</productname> database passwords are separate from
operating system user passwords. Ordinarily, the password for each
database user is stored in the pg_shadow system catalog table.
Passwords can be managed with the query language commands
<command>CREATE USER</command> and <command>ALTER USER</command>,
e.g., <userinput>CREATE USER foo WITH PASSWORD
'secret';</userinput>. By default, that is, if no password has
been set up, the stored password is <literal>NULL</literal>
and password authentication will always fail for that user.
<productname>PostgreSQL</productname> database passwords are
separate from operating system user passwords. Ordinarily, the
password for each database user is stored in the pg_shadow system
catalog table. Passwords can be managed with the query language
commands <command>CREATE USER</command> and <command>ALTER
USER</command>, e.g., <userinput>CREATE USER foo WITH PASSWORD
'secret';</userinput>. By default, that is, if no password has been
set up, the stored password is <literal>NULL</literal> and password
authentication will always fail for that user.
</para>
<para>
To restrict the set of users that are allowed to connect to certain
databases, list the set of users in a separate file (one user name
per line) in the same directory that <filename>pg_hba.conf</> is in,
and mention the (base) name of the file after the
<literal>password</>, <literal>md5</>, or <literal>crypt</> keyword,
respectively, in <filename>pg_hba.conf</>. If you do not use this
feature, then any user that is known to the database system can
connect to any database (so long as he supplies the correct password,
of course).
</para>
<para>
These files can also be used to apply a different set of passwords
to a particular database or set thereof. In that case, the files
have a format similar to the standard Unix password file
<filename>/etc/passwd</filename>, that is,
<synopsis>
<replaceable>username</replaceable>:<replaceable>password</replaceable>
</synopsis>
Any extra colon-separated fields following the password are
ignored. The password is expected to be encrypted using the
system's <function>crypt()</function> function. The utility
program <application>pg_passwd</application> that is installed
with <productname>PostgreSQL</productname> can be used to manage
these password files.
</para>
<para>
Lines with and without passwords can be mixed in secondary
password files. Lines without password indicate use of the main
password in <literal>pg_shadow</> that is managed by
<command>CREATE USER</> and <command>ALTER USER</>. Lines with
passwords will cause that password to be used. A password entry of
<quote>+</quote> also means using the pg_shadow password.
</para>
<para>
Alternative passwords cannot be used when using the <literal>md5</>
or <literal>crypt</> methods. The file will be read as
usual, but the password field will simply be ignored and the
<literal>pg_shadow</> password will always be used.
</para>
<para>
Note that using alternative passwords like this means that one can
no longer use <command>ALTER USER</command> to change one's
password. It will appear to work but the password one is
changing is not the password that the system will end up
using.
databases, list the users separated by commas, or in a separate
file. The file should contain user names separated by commas or one
user name per line, and be in the same directory as
<filename>pg_hba.conf</>. Mention the (base) name of the file
preceded with <literal>@</>in the <literal>USER</> column. The
<literal>DATABASE</> column can similarly accept a list of values or
a file name. You can also specify group names by preceding the group
name with <literal>+</>.
</para>
</sect2>
@ -588,10 +538,10 @@ local all md5 admins
<productname>Kerberos</productname> system is far beyond the scope
of this document; in all generality it can be quite complex (yet
powerful). The <ulink
url="http://www.nrl.navy.mil/CCS/people/kenh/kerberos-faq.html">Kerberos
<acronym>FAQ</></ulink> or <ulink
url="ftp://athena-dist.mit.edu">MIT Project Athena</ulink> can be
a good starting point for exploration. Several sources for
url="http://www.nrl.navy.mil/CCS/people/kenh/kerberos-faq.html">Kerb
eros <acronym>FAQ</></ulink> or <ulink
url="ftp://athena-dist.mit.edu">MIT Project Athena</ulink> can be a
good starting point for exploration. Several sources for
<productname>Kerberos</> distributions exist.
</para>
@ -606,34 +556,33 @@ local all md5 admins
<para>
<productname>PostgreSQL</> operates like a normal Kerberos service.
The name of the service principal is
<replaceable>servicename/hostname@realm</>, where
<replaceable>servicename</> is <literal>postgres</literal>
(unless a different service name was selected at configure time
with <literal>./configure --with-krb-srvnam=whatever</>).
<replaceable>hostname</> is the fully qualified domain name of the server
machine. The service principal's realm is the preferred realm of the
server machine.
<replaceable>servicename/hostname@realm</>, where
<replaceable>servicename</> is <literal>postgres</literal> (unless a
different service name was selected at configure time with
<literal>./configure --with-krb-srvnam=whatever</>).
<replaceable>hostname</> is the fully qualified domain name of the
server machine. The service principal's realm is the preferred realm
of the server machine.
</para>
<para>
Client principals must have their <productname>PostgreSQL</> user name as
their first component, for example
<replaceable>pgusername/otherstuff@realm</>.
At present the realm of the client is not checked by
<productname>PostgreSQL</>; so
if you have cross-realm authentication enabled, then any principal
in any realm that can communicate with yours will be accepted.
Client principals must have their <productname>PostgreSQL</> user
name as their first component, for example
<replaceable>pgusername/otherstuff@realm</>. At present the realm of
the client is not checked by <productname>PostgreSQL</>; so if you
have cross-realm authentication enabled, then any principal in any
realm that can communicate with yours will be accepted.
</para>
<para>
Make sure that your server key file is readable (and
preferably only readable) by the
<productname>PostgreSQL</productname> server account (see
<xref linkend="postgres-user">). The location of the key file
is specified with the <varname>krb_server_keyfile</> run time
configuration parameter. (See also <xref linkend="runtime-config">.)
The default is <filename>/etc/srvtab</> if you are using Kerberos 4
and <filename>FILE:/usr/local/pgsql/etc/krb5.keytab</> (or whichever
Make sure that your server key file is readable (and preferably only
readable) by the <productname>PostgreSQL</productname> server
account (see <xref linkend="postgres-user">). The location of the
key file is specified with the <varname>krb_server_keyfile</> run
time configuration parameter. (See also <xref
linkend="runtime-config">.) The default is <filename>/etc/srvtab</>
if you are using Kerberos 4 and
<filename>FILE:/usr/local/pgsql/etc/krb5.keytab</> (or whichever
directory was specified as <varname>sysconfdir</> at build time)
with Kerberos 5.
</para>
@ -649,18 +598,20 @@ local all md5 admins
<para>
When connecting to the database make sure you have a ticket for a
principal matching the requested database user name.
An example: For database user name <literal>fred</>, both principal
principal matching the requested database user name. An example: For
database user name <literal>fred</>, both principal
<literal>fred@EXAMPLE.COM</> and
<literal>fred/users.example.com@EXAMPLE.COM</> can be
used to authenticate to the database server.
<literal>fred/users.example.com@EXAMPLE.COM</> can be used to
authenticate to the database server.
</para>
<para>
If you use <application>mod_auth_krb</application> and <application>mod_perl</application> on your <productname>Apache</productname> web server,
you can use <literal>AuthType KerberosV5SaveCredentials</literal> with a <application>mod_perl</application>
script. This gives secure database access over the web, no extra
passwords required.
If you use <application>mod_auth_krb</application> and
<application>mod_perl</application> on your
<productname>Apache</productname> web server, you can use
<literal>AuthType KerberosV5SaveCredentials</literal> with a
<application>mod_perl</application> script. This gives secure
database access over the web, no extra passwords required.
</para>
</sect2>
@ -707,55 +658,54 @@ local all md5 admins
</para>
<para>
On systems supporting <symbol>SO_PEERCRED</symbol> requests for Unix-domain sockets,
ident authentication can also be applied to local connections. In this
case, no security risk is added by using ident authentication; indeed
it is a preferable choice for local connections on such a system.
On systems supporting <symbol>SO_PEERCRED</symbol> requests for
Unix-domain sockets, ident authentication can also be applied to
local connections. In this case, no security risk is added by using
ident authentication; indeed it is a preferable choice for local
connections on such systems.
</para>
<para>
When using ident-based authentication, after having determined the
name of the operating system user that initiated the connection,
<productname>PostgreSQL</productname> checks whether that user is allowed
to connect as the database user he is requesting to connect as.
This is controlled by the ident map
argument that follows the <literal>ident</> keyword in the
<filename>pg_hba.conf</filename> file. There is a predefined ident map
<literal>sameuser</literal>, which allows any operating system
user to connect as the database user of the same name (if the
latter exists). Other maps must be created manually.
<productname>PostgreSQL</productname> checks whether that user is
allowed to connect as the database user he is requesting to connect
as. This is controlled by the ident map argument that follows the
<literal>ident</> keyword in the <filename>pg_hba.conf</filename>
file. There is a predefined ident map <literal>sameuser</literal>,
which allows any operating system user to connect as the database
user of the same name (if the latter exists). Other maps must be
created manually.
</para>
<para>
<indexterm><primary>pg_ident.conf</primary></indexterm>
Ident maps other than <literal>sameuser</literal> are defined
in the file <filename>pg_ident.conf</filename>
in the data directory, which contains lines of the general form:
<indexterm><primary>pg_ident.conf</primary></indexterm> Ident maps
other than <literal>sameuser</literal> are defined in the file
<filename>pg_ident.conf</filename> in the data directory, which
contains lines of the general form:
<synopsis>
<replaceable>map-name</> <replaceable>ident-username</> <replaceable>database-username</>
</synopsis>
Comments and whitespace are handled in the usual way.
The <replaceable>map-name</> is an arbitrary name that will be
used to refer to this mapping in <filename>pg_hba.conf</filename>.
The other two fields specify which operating system user is
allowed to connect as which database user. The same
<replaceable>map-name</> can be used repeatedly to specify more
user-mappings within a single map. There is no restriction regarding
how many
database users a given operating system user may correspond to and vice
versa.
Comments and whitespace are handled in the usual way. The
<replaceable>map-name</> is an arbitrary name that will be used to
refer to this mapping in <filename>pg_hba.conf</filename>. The other
two fields specify which operating system user is allowed to connect
as which database user. The same <replaceable>map-name</> can be
used repeatedly to specify more user-mappings within a single map.
There is no restriction regarding how many database users a given
operating system user may correspond to and vice versa.
</para>
<para>
<indexterm>
<primary>SIGHUP</primary>
</indexterm>
The <filename>pg_ident.conf</filename> file is read on start-up
and when the <application>postmaster</> receives a
The <filename>pg_ident.conf</filename> file is read on start-up and
when the <application>postmaster</> receives a
<systemitem>SIGHUP</systemitem> signal. If you edit the file on an
active system, you will need to signal the <application>postmaster</>
(using <literal>pg_ctl reload</> or <literal>kill -HUP</>)
to make it re-read the file.
(using <literal>pg_ctl reload</> or <literal>kill -HUP</>) to make it
re-read the file.
</para>
<para>
@ -763,13 +713,14 @@ local all md5 admins
conjunction with the <filename>pg_hba.conf</> file in <xref
linkend="example-pg-hba.conf"> is shown in <xref
linkend="example-pg-ident.conf">. In this example setup, anyone
logged in to a machine on the 192.168 network that does not have
the Unix user name <systemitem>bryanh</>, <systemitem>ann</>, or <systemitem>robert</> would not be granted access.
Unix user <systemitem>robert</> would only be allowed access when he tries to
connect as <productname>PostgreSQL</> user <systemitem>bob</>,
not as <systemitem>robert</>
or anyone else. <systemitem>ann</> would only be allowed to connect as
<systemitem>ann</>. User <systemitem>bryanh</> would be allowed to connect as either
logged in to a machine on the 192.168 network that does not have the
Unix user name <systemitem>bryanh</>, <systemitem>ann</>, or
<systemitem>robert</> would not be granted access. Unix user
<systemitem>robert</> would only be allowed access when he tries to
connect as <productname>PostgreSQL</> user <systemitem>bob</>, not
as <systemitem>robert</> or anyone else. <systemitem>ann</> would
only be allowed to connect as <systemitem>ann</>. User
<systemitem>bryanh</> would be allowed to connect as either
<systemitem>bryanh</> himself or as <systemitem>guest1</>.
</para>
@ -780,7 +731,7 @@ local all md5 admins
omicron bryanh bryanh
omicron ann ann
# bob has username robert on these machines
# bob has user name robert on these machines
omicron robert bob
# bryanh can also connect as guest1
omicron bryanh guest1
@ -799,30 +750,30 @@ omicron bryanh guest1
<para>
<ProgramListing>
No pg_hba.conf entry for host 123.123.123.123, user joeblow, database testdb
No pg_hba.conf entry for host 123.123.123.123, user andym, database testdb
</ProgramListing>
This is what you are most likely to get if you succeed in
contacting the server, but it does not want to talk to you. As the
message suggests, the server refused the connection request
because it found no authorizing entry in its <filename>pg_hba.conf</filename>
This is what you are most likely to get if you succeed in contacting
the server, but it does not want to talk to you. As the message
suggests, the server refused the connection request because it found
no authorizing entry in its <filename>pg_hba.conf</filename>
configuration file.
</para>
<para>
<ProgramListing>
Password authentication failed for user 'joeblow'
Password authentication failed for user 'andym'
</ProgramListing>
Messages like this indicate that you contacted the server, and
it is willing to talk to you, but not until you pass the
authorization method specified in the
<filename>pg_hba.conf</filename> file. Check the password you are
providing, or check your Kerberos or ident software if the
complaint mentions one of those authentication types.
Messages like this indicate that you contacted the server, and it is
willing to talk to you, but not until you pass the authorization
method specified in the <filename>pg_hba.conf</filename> file. Check
the password you are providing, or check your Kerberos or ident
software if the complaint mentions one of those authentication
types.
</para>
<para>
<ProgramListing>
FATAL 1: user "joeblow" does not exist
FATAL 1: user "andym" does not exist
</ProgramListing>
The indicated user name was not found.
</para>
@ -837,9 +788,9 @@ FATAL 1: Database "testdb" does not exist in the system catalog.
</para>
<para>
Note that the server log may contain more information
about an authentication failure than is reported to the client.
If you are confused about the reason for a failure, check the log.
Note that the server log may contain more information about an
authentication failure than is reported to the client. If you are
confused about the reason for a failure, check the log.
</para>
</sect1>

3
doc/src/sgml/ref/allfiles.sgml
View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/allfiles.sgml,v 1.36 2002/03/19 02:18:12 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/allfiles.sgml,v 1.37 2002/04/04 04:25:45 momjian Exp $
PostgreSQL documentation
Complete list of usable sgml source files in this directory.
-->
@ -125,7 +125,6 @@ Complete list of usable sgml source files in this directory.
<!entity pgCtl system "pg_ctl-ref.sgml">
<!entity pgDump system "pg_dump.sgml">
<!entity pgDumpall system "pg_dumpall.sgml">
<!entity pgPasswd system "pg_passwd.sgml">
<!entity pgRestore system "pg_restore.sgml">
<!entity pgTclSh system "pgtclsh.sgml">
<!entity pgTkSh system "pgtksh.sgml">

123
doc/src/sgml/ref/pg_passwd.sgml
View File

@ -1,123 +0,0 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/Attic/pg_passwd.sgml,v 1.10 2001/12/08 03:24:38 thomas Exp $
PostgreSQL documentation
-->
<refentry id="APP-PG-PASSWD">
<docinfo>
<date>2000-11-18</date>
</docinfo>
<refmeta>
<refentrytitle id="APP-PG-PASSWD-TITLE"><application>pg_passwd</application></refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo>Application</refmiscinfo>
</refmeta>
<refnamediv>
<refname>pg_passwd</refname>
<refpurpose>change a secondary <productname>PostgreSQL</> password file</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>pg_passwd</command>
<arg choice="plain"><replaceable>filename</replaceable></arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id="app-pg-passwd-description">
<title>Description</title>
<para>
<application>pg_passwd</application> is a tool for manipulating flat
text password files. These files can control client authentication of
the <productname>PostgreSQL</productname> server. More information
about setting up this authentication mechanism can be found in the
<citetitle>Administrator's Guide</citetitle>.
</para>
<para>
The format of a text password file is one entry per line; the fields
of each entry are separated by colons. The first field is the user
name, the second field is the encrypted password. Other fields are
ignored (to allow password files to be shared between applications
that use similar formats). <application>pg_passwd</application>
enables users to interactively add entries to such a file, to alter
passwords of existing entries, and to encrypt such passwords.
</para>
<para>
Supply the name of the password file as argument to the
<application>pg_passwd</application> command. To be used by
PostgreSQL, the file needs to be located in the server's data
directory, and the base name of the file needs to be specified in the
<filename>pg_hba.conf</filename> access control file.
<screen>
<prompt>$</prompt> <userinput>pg_passwd /usr/local/pgsql/data/passwords</userinput>
<computeroutput>File "/usr/local/pgsql/data/passwords" does not exist. Create? (y/n):</computeroutput> <userinput>y</userinput>
<prompt>Username:</prompt> <userinput>guest</userinput>
<prompt>Password:</prompt>
<prompt>Re-enter password:</prompt>
</screen>
where the <literal>Password:</literal> and <literal>Re-enter
password:</literal> prompts require the same password input which
is not displayed on the terminal. Note that the password is limited
to eight useful characters by restrictions of the standard crypt(3)
library routine.
</para>
<para>
The original password file is renamed to
<filename>passwords.bk</filename>.
</para>
<para>
To make use of this password file, put a line like the following in
<filename>pg_hba.conf</filename>:
<programlisting>
host mydb 133.65.96.250 255.255.255.255 password passwords
</programlisting>
which would allow access to database mydb from host 133.65.96.250 using
the passwords listed in the <filename>passwords</filename> file (and
only to the users listed in that file).
</para>
<note>
<para>
It is also useful to have entries in a password file with empty
password fields. (This is different from an empty password.) Such
entries allow you to restrict users who can access the system. These
entries cannot be managed by <application>pg_passwd</application>,
but you can edit password files manually.
</para>
</note>
</refsect1>
<refsect1 id="app-pg-passwd-seealso">
<title>See also</title>
<para>
<citetitle>PostgreSQL Administrator's Guide</citetitle>
</para>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:nil
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"../reference.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:"/usr/lib/sgml/catalog"
sgml-local-ecat-files:nil
End:
-->

3
doc/src/sgml/reference.sgml
View File

@ -1,5 +1,5 @@
<!-- reference.sgml
$Header: /cvsroot/pgsql/doc/src/sgml/reference.sgml,v 1.24 2002/03/19 02:18:11 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/reference.sgml,v 1.25 2002/04/04 04:25:44 momjian Exp $
PostgreSQL Reference Manual
-->
@ -191,7 +191,6 @@ Disable this chapter until we have more functions documented.
&initlocation;
&ipcclean;
&pgCtl;
&pgPasswd;
&postgres;
&postmaster;