.TH SLAPD.ACCESS 5 "RELEASEDATE" "OpenLDAP LDVERSION"
-.\" Copyright 1998-2004 The OpenLDAP Foundation All Rights Reserved.
+.\" Copyright 1998-2005 The OpenLDAP Foundation All Rights Reserved.
.\" Copying restrictions apply. See COPYRIGHT/LICENSE.
.SH NAME
slapd.access \- access configuration for slapd, the stand-alone LDAP daemon
not applicable, the directives from the global configuration section
are then used.
.LP
+If no access controls are present, the default policy
+allows anyone and everyone to read anything but restricts
+updates to rootdn. (e.g., "access to * by * read").
+The rootdn can always read and write EVERYTHING!
+.LP
For entries not held in any backend (such as a root DSE), the
directives of the first backend (and any global directives) are
used.
.nf
[dn[.<dnstyle>]=]<dnpattern>
filter=<ldapfilter>
- attrs=<attrlist>[ val[.<attrstyle>]=<attrval>]
+ attrs=<attrlist>[ val[/matchingRule][.<attrstyle>]=<attrval>]
.fi
.LP
with
.BR regex ,
then
.B <dnpattern>
-is a regular expression pattern,
+is a POSIX (''extended'') regular expression pattern,
as detailed in
-.BR regex (7),
+.BR regex (7)
+and/or
+.BR re_format (7),
matching a normalized string representation of the entry's DN.
-The regex form of the pattern does not (yet) support UTF-8.
+The regex form of the pattern does not (yet) support UTF\-8.
.LP
The statement
.B filter=<ldapfilter>
is implied, i.e. all attributes are addressed.
.LP
Using the form
-.B attrs=<attr> val[.<style>]=<attrval>
+.B attrs=<attr> val[/matchingRule][.<attrstyle>]=<attrval>
specifies access to a particular value of a single attribute.
-In this case, only a single attribute type may be given. A value
-.B <style>
-of
+In this case, only a single attribute type may be given. The
+.B <attrstyle>
.B exact
(the default) uses the attribute's equality matching rule to compare the
-value. If the value
-.B <style>
+value, unless a different (and compatible) matching rule is specified. If the
+.B <attrstyle>
is
.BR regex ,
-the provided value is used as a regular expression pattern.
-If the attribute has DN syntax, the value
-.B <style>
+the provided value is used as a POSIX (''extended'') regular
+expression pattern. If the attribute has DN syntax, the
+.B <attrstyle>
can be any of
.BR base ,
.BR onelevel ,
*
anonymous
users
- self
+ self[.<selfstyle>]
dn[.<dnstyle>[,<modifier>]]=<DN>
dnattr=<attrname>
+
+ realanonymous
+ realusers
+ realself[.<selfstyle>]
+
+ realdn[.<dnstyle>[,<modifier>]]=<DN>
+ realdnattr=<attrname>
+
group[/<objectclass>[/<attrname>]]
[.<groupstyle>]=<group>
peername[.<peernamestyle>]=<peername>
tls_ssf=<n>
sasl_ssf=<n>
- aci=<attrname>
+ aci[=<attrname>]
+ dynacl/name[/<options>][.<dynstyle>][=<pattern>]
.fi
.LP
with
.LP
.nf
<style>={exact|regex|expand}
+ <selfstyle>={level{<n>}}
<dnstyle>={{exact|base(object)}|regex
- |one(level)|sub(tree)|children}
+ |one(level)|sub(tree)|children|level{<n>}}
<groupstyle>={exact|expand}
<peernamestyle>={<style>|ip|path}
<domainstyle>={exact|regex|sub(tree)}
.B *
refers to everybody.
.LP
+The keywords prefixed by
+.B real
+act as their counterparts without prefix; the checking respectively occurs
+with the \fIauthentication\fP DN and the \fIauthorization\fP DN.
+.LP
The keyword
.B anonymous
means access is granted to unauthenticated clients; it is mostly used
.B self
means access to an entry is allowed to the entry itself (e.g. the entry
being accessed and the requesting entry must be the same).
+It allows the
+.B level{<n>}
+style, where \fI<n>\fP indicates what ancestor of the DN
+is to be used in matches.
+A positive value indicates that the <n>-th ancestor of the user's DN
+is to be considered; a negative value indicates that the <n>-th ancestor
+of the target is to be considered.
+For example, a "\fIby self.level{1} ...\fP" clause would match
+when the object "\fIdc=example,dc=com\fP" is accessed
+by "\fIcn=User,dc=example,dc=com\fP".
+A "\fIby self.level{-1} ...\fP" clause would match when the same user
+accesses the object "\fIou=Address Book,cn=User,dc=example,dc=com\fP".
.LP
The statement
.B dn=<DN>
.BR $<digit> ,
with
.B digit
-ranging from 1 to 9.
+ranging from 0 to 9 (where 0 matches the entire string),
+or the form
+.BR ${<digit>+} ,
+for submatches higher than 9.
Since the dollar character is used to indicate a substring replacement,
the dollar character that is used to indicate match up to the end of
the string must be escaped by a second dollar character, e.g.
Note that the
.B regex
dnstyle in the above example may be of use only if the
-.B by
+.B <by>
clause needs to be a regex; otherwise, if the
value of the second (from the right)
.B dc=
.fi
.LP
could be used; if it had to match the value in the
-.B what
+.B <what>
clause, the form
.LP
.nf
.LP
could be used.
.LP
+Forms of the
+.B <what>
+clause other than regex may provide submatches as well.
+The
+.BR base(object) ,
+the
+.BR sub(tree) ,
+the
+.BR one(level) ,
+and the
+.BR children
+forms provide
+.B $0
+as the match of the entire string.
+The
+.BR sub(tree) ,
+the
+.BR one(level) ,
+and the
+.BR children
+forms also provide
+.B $1
+as the match of the rightmost part of the DN as defined in the
+.B <what>
+clause.
+This may be useful, for instance, to provide access to all the
+ancestors of a user by defining
+.LP
+.nf
+ access to dn.subtree="dc=com"
+ by dn.subtree,expand="$1" read
+.fi
+.LP
+which means that only access to entries that appear in the DN of the
+.B <by>
+clause is allowed.
+.LP
+The
+.BR level{<n>}
+form is an extension and a generalization of the
+.BR onelevel
+form, which matches all DNs whose <n>-th ancestor is the pattern.
+So, \fIlevel{1}\fP is equivalent to \fIonelevel\fP,
+and \fIlevel{0}\fP is equivalent to \fIbase\fP.
+.LP
It is perfectly useless to give any access privileges to a DN
that exactly matches the
.B rootdn
and
.B <attrname>
define the objectClass and the member attributeType of the group entry.
+The defaults are
+.B groupOfNames
+and
+.BR member ,
+respectively.
The optional style qualifier
.B <style>
can be
which means that
.B <group>
will be expanded as a replacement string (but not as a regular expression)
-according to regex (7), and
+according to
+.BR regex (7)
+and/or
+.BR re_format (7),
+and
.BR exact ,
which means that exact match will be used.
+If the style of the DN portion of the
+.B <what>
+clause is regex, the submatches are made available according to
+.BR regex (7)
+and/or
+.BR re_format (7);
+other styles provide limited submatches as discussed above about
+the DN form of the
+.B <by>
+clause.
.LP
For static groups, the specified attributeType must have
.B DistinguishedName
.B regex
style, which implies submatch
.B expand
-and
-.BR regex (7)
-match of the corresponding connection parameters.
+and regex match of the corresponding connection parameters.
The
.B exact
style of the
-.BR peername
+.BR <peername>
clause (the default) implies a case-exact match on the client's
.BR IP ,
including the
when connecting through a named pipe, and performs an exact match
on the given pattern.
The
-.BR domain
+.BR <domain>
clause also allows the
.B subtree
style, which succeeds when a fully qualified name exactly matches the
The optional
.B domainstyle
qualifier of the
-.B domain
+.B <domain>
clause allows a
.B modifier
option; the only value currently supported is
is not
.BR regex ,
much like the analogous usage in
-.B dn
+.B <dn>
clause.
.LP
The statement
is undocumented yet.
.LP
The statement
-.B aci=<attrname>
+.B aci[=<attrname>]
means that the access control is determined by the values in the
.B attrname
of the entry itself.
+The optional
+.B <attrname>
+indicates what attributeType holds the ACI information in the entry.
+By default, the
+.B OpenLDAPaci
+operational attribute is used.
ACIs are experimental; they must be enabled at compile time.
.LP
+The statement
+.B dynacl/<name>[/<options>][.<dynstyle>][=<pattern>]
+means that access checking is delegated to the admin-defined method
+indicated by
+.BR <name> ,
+which can be registered at run-time by means of the
+.B moduleload
+statement.
+The fields
+.BR <options> ,
+.B <dynstyle>
+and
+.B <pattern>
+are optional, and are directly passed to the registered parsing routine.
+Dynacl is experimental; it must be enabled at compile time.
+If dynacl and ACIs are both enabled, ACIs are cast into the dynacl scheme,
+where
+.B <name>=aci
+and, optionally,
+.BR <patten>=<attrname> .
+However, the original ACI syntax is preserved for backward compatibility.
+.LP
The statements
.BR ssf=<n> ,
.BR transport_ssf=<n> ,
to grant access. The value should be positive integer.
.SH THE <ACCESS> FIELD
The field
-.B <access> ::= [self]{<level>|<priv>}
+.B <access> ::= [[real]self]{<level>|<priv>}
determines the access level or the specific access privileges the
.B who
field will have.
Its component are defined as
.LP
.nf
- <level> ::= none|auth|compare|search|read|write
- <priv> ::= {=|+|-}{w|r|s|c|x|0}+
+ <level> ::= none|disclose|auth|compare|search|read|write
+ <priv> ::= {=|+|-}{w|r|s|c|x|d|0}+
.fi
.LP
The modifier
allows special operations like having a certain access level or privilege
only in case the operation involves the name of the user that's requesting
the access.
-It implies the user that requests access is bound.
+It implies the user that requests access is authorized.
+The modifier
+.B realself
+refers to the authenticated DN as opposed to the authorized DN of the
+.B self
+modifier.
An example is the
.B selfwrite
access to the member attribute of a group, which allows one to add/delete
privileges.
The possible levels are
.BR none ,
+.BR disclose ,
.BR auth ,
.BR compare ,
.BR search ,
Each access level implies all the preceding ones, thus
.B write
access will imply all accesses.
-While
-.B none
-is trivial,
+.LP
+The
+.B none
+access level disallows all access including disclosure on error.
+.LP
+The
+.B disclose
+access level allows disclosure of information on error.
+.LP
+The
.B auth
-access means that one is allowed access to an attribute to perform
+access level means that one is allowed access to an attribute to perform
authentication/authorization operations (e.g.
.BR bind )
with no other access.
.B s
for search,
.B c
-for compare, and
+for compare,
.B x
-for authentication.
+for authentication, and
+.B d
+for disclose.
More than one of the above privileges can be added in one statement.
.B 0
indicates no privileges and is used only by itself (e.g., +0).
-.LP
+If no access is given, it defaults to
+.BR +0 .
+.SH THE <CONTROL> FIELD
The optional field
.B <control>
controls the flow of access rule application.
.LP
which grants everybody search and compare privileges, and adds read
privileges to authenticated clients.
+.LP
+One useful application is to easily grant write privileges to an
+.B updatedn
+that is different from the
+.BR rootdn .
+In this case, since the
+.B updatedn
+needs write access to (almost) all data, one can use
+.LP
+.nf
+ access to *
+ by dn.exact="cn=The Update DN,dc=example,dc=com" write
+ by * break
+.fi
+.LP
+as the first access rule.
+As a consequence, unless the operation is performed with the
+.B updatedn
+identity, control is passed straight to the subsequent rules.
.SH OPERATION REQUIREMENTS
Operations require different privileges on different portions of entries.
The following summary applies to primary database backends such as
.B modify
operation requires
.B write (=w)
-privileges on the attibutes being modified.
+privileges on the attributes being modified.
.LP
The
.B modrdn
.LP
The
.B search
-operation, for each entry, requires
+operation, requires
+.B search (=s)
+privileges on the
+.B entry
+pseudo-attribute of the searchBase (NOTE: this was introduced with 2.3).
+Then, for each entry, it requires
.B search (=s)
privileges on the attributes that are defined in the filter.
-Then, the resulting entries are tested for
+The resulting entries are finally tested for
.B read (=r)
privileges on the pseudo-attribute
.B entry
attribute of the authorizing identity and/or on the
.B authzFrom
attribute of the authorized identity.
+
+.LP
+Access control to search entries is checked by the frontend,
+so it is fully honored by all backends; for all other operations
+and for the discovery phase of the search operation,
+full ACL semantics is only supported by the primary backends, i.e.
+.BR back-bdb (5),
+.BR back-hdb (5),
+and
+.BR back-ldbm (5).
+
+Some other backend, like
+.BR back-sql (5),
+may fully support them; others may only support a portion of the
+described semantics, or even differ in some aspects.
+The relevant details are described in the backend-specific man pages.
+
.SH CAVEATS
It is strongly recommended to explicitly use the most appropriate
.B <dnstyle>
and
.B <who>
clauses, to avoid possible incorrect specifications of the access rules
-as well as for performance (avoid unrequired regex matching when an exact
+as well as for performance (avoid unnecessary regex matching when an exact
match suffices) reasons.
.LP
An administrator might create a rule of the form:
.B <dnstyle>
use; for instance, to allow access to the subtree of the user
that matches the
-.B what
+.B <what>
clause, one could use
.LP
.nf
.fi
.LP
However, since all that is required in the
-.B by
+.B <by>
clause is substring expansion, a more efficient solution is
.LP
.nf
default slapd configuration file
.SH SEE ALSO
.BR slapd (8),
+.BR slapd-* (5),
.BR slapacl (8),
+.BR regex (7),
+.BR re_format (7)
.LP
"OpenLDAP Administrator's Guide" (http://www.OpenLDAP.org/doc/admin/)
.SH ACKNOWLEDGEMENTS