-.TH SLAPD.ACCESS 5 "28 Oct 2001" "OpenLDAP LDVERSION"
-.\" Copyright 1998-2002 The OpenLDAP Foundation All Rights Reserved.
+.TH SLAPD.ACCESS 5 "RELEASEDATE" "OpenLDAP LDVERSION"
+.\" Copyright 1998-2004 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
daemon. This configuration file is also used by the
.BR slurpd (8)
replication daemon and by the SLAPD tools
+.BR slapacl (8),
.BR slapadd (8),
+.BR slapauth (8),
.BR slapcat (8),
+.BR slapdn (8),
+.BR slapindex (8),
and
-.BR slapindex (8).
+.BR slaptest (8).
.LP
The
.B slapd.conf
...
.fi
.LP
-Both the global configuration and each backend-specific section can contain
-access information.
-Backend-specific access control directives are used for those entries
-that belong to the backend, according to their naming context.
-In case no access control directives are defined for a backend,
-the appropriate directives from the global configuration section
-are used.
-.LP
-Arguments that should be replaced by actual text are shown in brackets <>.
+Both the global configuration and each backend-specific section can
+contain access information. Backend-specific access control
+directives are used for those entries that belong to the backend,
+according to their naming context. In case no access control
+directives are defined for a backend or those which are defined are
+not applicable, the directives from the global configuration section
+are then used.
+.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.
+.LP
+Arguments that should be replaced by actual text are shown in
+brackets <>.
+.SH THE ACCESS DIRECTIVE
The structure of the access control directives is
.TP
-.B access to <what> [ by <who> <access> [ <control> ] ]+
+.B access to <what> "[ by <who> <access> [ <control> ] ]+"
Grant access (specified by
.BR <access> )
to a set of entries and/or attributes (specified by
.BR <what> )
by one or more requestors (specified by
.BR <who> ).
-.LP
+.SH THE <WHAT> FIELD
The field
.BR <what>
specifies the entity the access control directive applies to.
.LP
.nf
*
- [dn[.<dnstyle>]=<pattern>]
+ [dn[.<dnstyle>]=<DN>]
[filter=<ldapfilter>]
- [attrs=<attrlist>]
+ [attrs=<attrlist>[ val[.<style>]=<attrval>]]
.fi
.LP
The wildcard
stands for all the entries.
.LP
The statement
-.B dn=<pattern>
+.B dn=<DN>
selects the entries based on their naming context.
-The optional style qualificator
-.B <dnstyle>
-can be
-.BR regex ,
-which implies a regular expression pattern, as detailed in
-.BR regex (7),
-will be used (the default),
-.B base
+The pattern is a string representation of the entry's DN.
+.BR base ,
+the default,
or
.B exact
(an alias of
.BR base )
-for an exact match of the entry,
+indicates the entry whose DN is equal to the pattern;
.B one
-to indicate all the entries immediately below the
+(synonym of
+.BR onelevel )
+indicates all the entries immediately below the
.BR pattern ,
.B sub
-to indicate all the subentries of an entry including the entry itself,
+(synonym of
+.BR subtree )
+indicates all entries in the subtree at the pattern,
.B children
-to indicate all the subentries of an entry not including the entry itself.
-Note that
-.B dn=".*"
-is equivalent to
-.BR * .
-The regex form of the pattern does not support UTF-8 (7) yet.
+indicates all the entries below (subordinate to) the pattern.
+.LP
+If the
+.B <dnstyle>
+qualifier is
+.BR regex ,
+then the value is a regular expression pattern,
+as detailed in
+.BR regex (7),
+matching a normalized string representation of the entry's DN.
+The regex form of the pattern does not (yet) support UTF-8.
.LP
The statement
.B filter=<ldapfilter>
.BR entry ,
indicating access to the entry itself, and
.BR children ,
-indicating access to the entry's children.
+indicating access to the entry's children. ObjectClass names may also
+be specified in this list, which will affect all the attributes that
+are required and/or allowed by that objectClass.
+Actually, names in
+.B <attrlist>
+that are prefixed by
+.B @
+are directly treated as objectClass names. A name prefixed by
+.B !
+is also treated as an objectClass, but in this case the access rule
+affects the attributes that are not required nor allowed
+by that objectClass.
+.LP
+Using the form
+.B attrs=<attr> val[.<style>]=<value>
+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
+.B exact
+(the default) uses the attribute's equality matching rule to compare the
+value. If the value
+.B <style>
+is
+.BR regex ,
+the provided value is used as a regular expression pattern.
+If the attribute has DN syntax, the value
+.B <style>
+can be any of
+.BR base ,
+.BR onelevel ,
+.B subtree
+or
+.BR children ,
+resulting in base, onelevel, subtree or children match, respectively.
.LP
-The last three statements are additive; they can be used in sequence
+The dn, filter, and attrs statements are additive; they can be used in sequence
to select entities the access rule applies to based on naming context,
value and attribute type simultaneously.
-.LP
+.SH THE <WHO> FIELD
The field
.B <who>
indicates whom the access rules apply to.
users
self
- dn[.<dnstyle>]=<pattern>
+ dn[.<dnstyle>[,<modifier>]]=<DN>
dnattr=<attrname>
group[/<objectclass>[/<attrname>]]
- [.<style>]=<pattern>
- peername[.<style>]=<pattern>
- sockname[.<style>]=<pattern>
- domain[.<style>]=<pattern>
- sockurl[.<style>]=<pattern>
- set[.<style>]=<pattern>
+ [.<groupstyle>]=<group>
+ peername[.<peernamestyle>]=<peername>
+ sockname[.<style>]=<sockname>
+ domain[.<domainstyle>[,<modifier>]]=<domain>
+ sockurl[.<style>]=<sockurl>
+ set[.<s
etstyle>]=<pattern>
ssf=<n>
transport_ssf=<n>
aci=<attrname>
.fi
.LP
+with
+.LP
+.nf
+ <dnstyle>={{exact|base}|regex|sub(tree)|one(level)|children}
+ <groupstyle>={exact|expand}
+ <style>={exact|regex|expand}
+ <peernamestyle>={<style>|ip|path}
+ <domainstyle>={exact|regex|sub(tree)}
+ <setstyle>={exact|regex}
+ <modifier>={expand}
+.fi
+.LP
They may be specified in combination.
.LP
.nf
.LP
The keyword
.B anonymous
-means access is granted to unauthenticated users; it is moslty used
+means access is granted to unauthenticated clients; it is mostly used
to limit access to authentication resources (e.g. the
.B userPassword
-attribute) to unauthenticated users for authentication purposes.
+attribute) to unauthenticated clients for authentication purposes.
.LP
The keyword
.B users
-means access is granted to authenticated users.
+means access is granted to authenticated clients.
.LP
The keyword
.B self
being accessed and the requesting entry must be the same).
.LP
The statement
-.B dn=<pattern>
-means that access is granted to the matching dn.
-The optional style qualificator
+.B dn=<DN>
+means that access is granted to the matching DN.
+The optional style qualifier
.B dnstyle
allows the same choices of the dn form of the
.B <what>
-field.
-In detail, the
+field. In addition, the
.B regex
-form of
-.B pattern
-can exploit substring substitution of submatches in the
+style can exploit substring substitution of submatches in the
.B <what>
-dn by using the form
+dn.regex clause by using the form
.BR $<digit> ,
with
.B digit
ranging from 1 to 9.
+Since the dollar character is used to indicate a substring replacement,
+the dollar character that is used to indicate match up to the end of
+the string must be escaped by a second dollar character, e.g.
+.LP
+.nf
+ access to dn.regex="^(.+,)?uid=([^,]+),dc=[^,]+,dc=com$"
+ by dn.regex="^uid=$2,dc=[^,]+,dc=com$$" write
+.fi
+.LP
+The style qualifier
+allows an optional
+.BR modifier .
+At present, the only type allowed is
+.BR expand ,
+which causes substring substitution of submatches to take place
+even if
+.B dnstyle
+is not
+.BR regex .
+Note that the
+.I regex
+dnstyle in the above example may be of use only if the
+.B by
+clause needs to be a regex; otherwise, if the
+value of the second (from the right)
+.I dc=
+portion of the DN in the above example were fixed, the form
+.LP
+.nf
+ access to dn.regex="^(.+,)?uid=([^,]+),dc=example,dc=com$"
+ by dn.exact,expand="uid=$2,dc=example,dc=com" write
+.fi
+.LP
+could be used; if it had to match the value in the
+.B what
+clause, the form
+.LP
+.nf
+ access to dn.regex="^(.+,)?uid=([^,]+),dc=([^,]+),dc=com$"
+ by dn.exact,expand="uid=$2,dc=$3,dc=com" write
+.fi
+.LP
+could be used.
+.LP
+It is perfectly useless to give any access privileges to a DN
+that exactly matches the
+.B rootdn
+of the database the ACLs apply to, because it implicitly
+possesses write privileges for the entire tree of that database.
+Actually, access control is bypassed for the
+.BR rootdn ,
+to solve the intrinsic chicken-and-egg problem.
.LP
The statement
.B dnattr=<attrname>
-means that access is granted to requests whose dn is listed in the
+means that access is granted to requests whose DN is listed in the
entry being accessed under the
-.B attrname
+.B <attrname>
attribute.
.LP
The statement
-.B group=<pattern>
-means that access is granted to requests whose dn is listed
-in the group entry whose dn is given by
-.BR pattern .
+.B group=<group>
+means that access is granted to requests whose DN is listed
+in the group entry whose DN is given by
+.BR <group> .
The optional parameters
-.B objectclass
+.B <objectclass>
and
-.B attrname
+.B <attrname>
define the objectClass and the member attributeType of the group entry.
-The optional style qualificator
-.B style
+The optional style qualifier
+.B <style>
can be
-.BR regex ,
+.BR expand ,
which means that
-.B pattern
-will be expanded accorging to regex (7), and
-.B base
+.B <group>
+will be expanded as a replacement string (but not as a regular expression)
+according to regex (7), and
+.BR exact ,
+which means that exact match will be used.
+.LP
+For static groups, the specified attributeType must have
+.B DistinguishedName
or
-.B exact
-(an alias of
-.BR base ),
-which means that an exact match will be used.
+.B NameAndOptionalUID
+syntax. For dynamic groups the attributeType must
+be a subtype of the
+.B labeledURI
+attributeType. Only LDAP URIs of the form
+.B ldap:///<base>??<scope>?<filter>
+will be evaluated in a dynamic group, by searching the local server only.
.LP
The statements
-.BR peername=<pattern> ,
-.BR sockname=<pattern> ,
-.BR domain=<pattern> ,
+.BR peername=<peername> ,
+.BR sockname=<sockname> ,
+.BR domain=<domain> ,
and
-.BR sockurl=<pattern>
-mean that the contacting host IP for
+.BR sockurl=<sockurl>
+mean that the contacting host IP (in the form
+.BR "IP=<ip>:<port>" )
+or the contacting host named pipe file name (in the form
+.B "PATH=<path>"
+if connecting through a named pipe) for
.BR peername ,
the named pipe file name for
.BR sockname ,
.B style
rules for pattern match described for the
.B group
-case apply.
+case apply, plus the
+.B regex
+style, which implies submatch
+.B expand
+and
+.BR regex (7)
+match of the corresponding connection parameters.
+The
+.B exact
+style of the
+.BR peername
+clause (the default) implies a case-exact match on the client's
+.BR IP ,
+including the
+.B "IP="
+prefix and the trailing
+.BR ":<port>" ,
+or the client's
+.BR path ,
+including the
+.B "PATH="
+prefix if connecting through a named pipe.
+The special
+.B ip
+style interprets the pattern as
+.BR <peername>=<ip>[%<mask>][{<n>}] ,
+where
+.B <ip>
+and
+.B <mask>
+are dotted digit representations of the IP and the mask, while
+.BR <n> ,
+delimited by curly brackets, is an optional port.
+When checking access privileges, the IP portion of the
+.BR peername
+is extracted, eliminating the
+.B "IP="
+prefix and the
+.B ":<port>"
+part, and it is compared against the
+.B <ip>
+portion of the pattern after masking with
+.BR <mask> .
+As an example,
+.B peername.ip=127.0.0.1
+alows connections only from localhost,
+.B peername.ip=192.168.1.0%255.255.255.0
+allows connections from any IP in the 192.168.1 class C domain, and
+.B peername.ip=192.168.1.16%255.255.255.240{9009}
+allows connections from any IP in the 192.168.1.[16-31] range
+of the same domain, only if port 9009 is used.
+The special
+.B path
+style eliminates the
+.B "PATH="
+prefix from the
+.B peername
+when connecting through a named pipe, and performs an exact match
+on the given pattern.
+The
+.BR domain
+clause also allows the
+.B subtree
+style, which succeeds when a fully qualified name exactly matches the
+.BR domain
+pattern, or its trailing part, after a
+.BR dot ,
+exactly matches the
+.BR domain
+pattern.
+The
+.B expand
+style is allowed, implying an
+.B exact
+match with submatch expansion; the use of
+.B expand
+as a style modifier is considered more appropriate.
+As an example,
+.B domain.subtree=example.com
+will match www.example.com, but will not match www.anotherexample.com.
+The
+.B domain
+of the contacting host is determined by performing a DNS reverse lookup.
+As this lookup can easily be spoofed, use of the
+.B domain
+statement is strongly discouraged. By default, reverse lookups are disabled.
+The optional
+.B domainstyle
+qualifier of the
+.B domain
+clause allows a
+.B modifier
+option; the only value currently supported is
+.BR expand ,
+which causes substring substitution of submatches to take place even if
+the
+.B domainstyle
+is not
+.BR regex ,
+much like the analogous usage in
+.B dn
+clause.
.LP
The statement
.B set=<pattern>
and
.BR sasl_ssf=<n>
set the required Security Strength Factor (ssf) required to grant access.
-.LP
+.SH THE <ACCESS> FIELD
The field
.B <access> ::= [self]{<level>|<priv>}
determines the access level or the specific access privileges the
.LP
.nf
<level> ::= none|auth|compare|search|read|write
- <priv> ::= {=|+|-}{w|r|s|c|x}+
+ <priv> ::= {=|+|-}{w|r|s|c|x|0}+
.fi
.LP
The modifier
authentication/authorization operations (e.g.
.BR bind )
with no other access.
-This is useful to grant unauthenticated users the least possible
+This is useful to grant unauthenticated clients the least possible
access level to critical resources, like passwords.
.LP
The
for compare, and
.B x
for authentication.
-More than one privilege can be added in one statement.
+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
The optional field
.B <control>
.fi
.LP
which allows search and compare privileges to everybody under
-the "dc=example,dc=com" tree, with the seconf rule allowing
+the "dc=example,dc=com" tree, with the second rule allowing
also read in the "ou=People" subtree,
or the (even more silly) example
.LP
.fi
.LP
which grants everybody search and compare privileges, and adds read
-privileges to authenticated users.
+privileges to authenticated clients.
+.SH OPERATION REQUIREMENTS
+Operations require different privileges on different portions of entries.
+The following summary applies to primary database backends such as
+the LDBM, BDB, and HDB backends. Requirements for other backends may
+(and often do) differ.
+.LP
+The
+.B add
+operation requires
+.B write (=w)
+privileges on the pseudo-attribute
+.B entry
+of the entry being added, and
+.B write (=w)
+privileges on the pseudo-attribute
+.B children
+of the entry's parent.
+.LP
+The
+.B bind
+operation, when credentials are stored in the directory, requires
+.B auth (=x)
+privileges on the attribute the credentials are stored in (usually
+.BR userPassword ).
+.LP
+The
+.B compare
+operation requires
+.B compare (=c)
+privileges on the attribute that is being compared.
+.LP
+The
+.B delete
+operation requires
+.B write (=w)
+privileges on the pseudo-attribute
+.B entry
+of the entry being deleted, and
+.B write (=w)
+privileges on the
+.B children
+pseudo-attribute of the entry's parent.
+.LP
+The
+.B modify
+operation requires
+.B write (=w)
+privileges on the attibutes being modified.
+.LP
+The
+.B modrdn
+operation requires
+.B write (=w)
+privileges on the pseudo-attribute
+.B entry
+of the entry whose relative DN is being modified,
+.B write (=w)
+privileges on the pseudo-attribute
+.B children
+of the old and new entry's parents, and
+.B write (=w)
+privileges on the attributes that are present in the new relative DN.
+.B Write (=w)
+privileges are also required on the attributes that are present
+in the old relative DN if
+.B deleteoldrdn
+is set to 1.
+.LP
+The
+.B search
+operation, for each entry, requires
+.B search (=s)
+privileges on the attributes that are defined in the filter.
+Then, the resulting entries are tested for
+.B read (=r)
+privileges on the pseudo-attribute
+.B entry
+(for read access to the entry itself)
+and for
+.B read (=r)
+access on each value of each attribute that is requested.
+Also, for each
+.B referral
+object used in generating continuation references, the operation requires
+.B read (=r)
+access on the pseudo-attribute
+.B entry
+(for read access to the referral object itself),
+as well as
+.B read (=r)
+access to the attribute holding the referral information
+(generally the
+.B ref
+attribute).
+.LP
+Some internal operations and some
+.B controls
+require specific access privileges.
+The
+.B authzID
+mapping and the
+.B proxyAuthz
+control require
+.B auth (=x)
+privileges on all the attributes that are present in the search filter
+of the URI regexp maps (the right-hand side of the
+.B authz-regexp
+directives).
+.B Auth (=x)
+privileges are also required on the
+.B authzTo
+attribute of the authorizing identity and/or on the
+.B authzFrom
+attribute of the authorized identity.
+.SH CAVEATS
+It is strongly recommended to explicitly use the most appropriate
+.B <dnstyle>
+in
+.B <what>
+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
+match suffices) reasons.
+.LP
+An administrator might create a rule of the form:
+.LP
+.nf
+ access to dn.regex="dc=example,dc=com"
+ by ...
+.fi
+.LP
+expecting it to match all entries in the subtree "dc=example,dc=com".
+However, this rule actually matches any DN which contains anywhere
+the substring "dc=example,dc=com". That is, the rule matches both
+"uid=joe,dc=example,dc=com" and "dc=example,dc=com,uid=joe".
+.LP
+To match the desired subtree, the rule would be more precisely
+written:
+.LP
+.nf
+ access to dn.regex="^(.+,)?dc=example,dc=com$"
+ by ...
+.fi
+.LP
+For performance reasons, it would be better to use the subtree style.
+.LP
+.nf
+ access to dn.subtree="dc=example,dc=com"
+ by ...
+.fi
+.LP
+When writing submatch rules, it may be convenient to avoid unnecessary
+.B regex
+.B <dnstyle>
+use; for instance, to allow access to the subtree of the user
+that matches the
+.B what
+clause, one could use
+.LP
+.nf
+ access to dn.regex="^(.+,)?uid=([^,]+),dc=example,dc=com$"
+ by dn.regex="^uid=$1,dc=example,dc=com$$" write
+ by ...
+.fi
+.LP
+However, since all that is required in the
+.B by
+clause is substring expansion, a more efficient solution is
+.LP
+.nf
+ access to dn.regex="^(.+,)?uid=([^,]+),dc=example,dc=com$"
+ by dn.exact,expand="uid=$1,dc=example,dc=com" write
+ by ...
+.fi
+.LP
+In fact, while a
+.B <dnstyle>
+of
+.B regex
+implies substring expansion,
+.BR exact ,
+as well as all the other DN specific
+.B <dnstyle>
+values, does not, so it must be explicitly requested.
+.LP
.SH FILES
+.TP
ETCDIR/slapd.conf
+default slapd configuration file
.SH SEE ALSO
.BR slapd (8),
+.BR slapacl (8),
.LP
"OpenLDAP Administrator's Guide" (http://www.OpenLDAP.org/doc/admin/)
.SH ACKNOWLEDGEMENTS
projects / openldap / blobdiff