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I've re-read my original message and it didn't make alot of sense. So here's take two!
I'm using back-meta to attempt to amalgamate several ldap servers into one single tree. This should cater for users that exist only in a local BDB database, and also for users with accounts in one of the target ldap servers. If I say 'local' or 'remote' user at any point, I'm referring to users stored in the local bdb database or a remote ldap server respectively. I shall refer to the local openldap server as the proxy server.
The meta database is subordinate to the local database. This allows me to have a base record for the entire directory.
Everything works perfectly for targets that don't require a bind before searching. For targets that do require a successful bind, I've been trying to use the 'idassert-bind' feature with mixed results. The following is a description of the behaviour I am trying to achieve:
If a local user binds to the proxy server, and performs a query with one or more targets in scope, then the proxy server should use predefined credentials to bind to and search only the targets in scope on behalf of the local user.
If a remote user binds to the proxy server, and performs a query affecting only the target where that user is stored, then the proxy server should bind to that target using the credentials supplied by the remote user. If there are any other targets in the scope of the query, openldap should not attempt to use the predefined credentials to bind to and search on that target.
To try to achieve this, I have placed all local users in their own branch of the tree, and set the 'idassert-authzFrom' for each target to match this branch only, thus preventing remote users from using the idassert feauture and barring them from querying other targets than their own.
Here is the first of two 'interesting' results. If I bind to the proxy server as a remote user with multiple targets in scope, the bind is proxied to the remote user's target correctly. The proxy then proceeds to attempt to bind to the other targets in scope using seemingly random names. Some examples (captured with wireshark) are '\270+1\b', '\250\202/\b\005', '\220\241\322\267\220\241\322\267\020' and 'x\267.\b'. The name changes every time, but each time no password is provided. The proxy will not attempt to search any of the targets after binding, even the target to which the user belongs.
I'm not sure I understand the purpose of the 'non-prescriptive' flag, but if I set it on each target (as Pierangelo suggested previously), the unusual behaviour changes. When binding with a remote user, the proxy will correctly bind to the target to which the remote user belongs using the remote users credentials. If another target is in scope, the proxy will attempt to bind to it without name or password. The proxy will proceed to search the targets. This is fine for my situation, but I would like to understand why this happens?
The second problem I'm having is with the local users. If the 'network-timeout' statement is used in the meta database definition, whenever a local user binds to the proxy and queries one or more of the target servers, the proxy will attempt to bind to the targets with the predefined name but with no password. If network-timeout is not specified, the proxy binds with both the predefined name and password to every target in scope. Is this behaviour intended or a bug?
My current configuration is...
require authc
access to * by * write
# # Meta #
database meta suffix "dc=meta,dc=example,dc=com" subordinate
rootdn "cn=manager,dc=example,dc=com"
network-timeout 10
#Target 1
uri "ldap://ldap.acme.org/dc=target1,dc=meta,dc=example,dc=com"
idassert-bind bindmethod=simple binddn="cn=searchuser,dc=acme,dc=org" credentials="secret" mode=none flags=non-prescriptive
idassert-authzFrom "dn.regex:dc=users,dc=example,dc=com"
rewriteEngine on
suffixmassage "dc=target1,dc=meta,dc=example,dc=com" "dc=acme,dc=org"
#Target 2
uri "ldap://ldap.another.com/dc=target2,dc=meta,dc=example,dc=com"
idassert-bind bindmethod=simple binddn="cn=searchuser,dc=another,dc=com" credentials="secret" mode=none flags=non-prescriptive
idassert-authzFrom "dn.regex:dc=users,dc=example,dc=com"
rewriteEngine on
suffixmassage "dc=target2,dc=meta,dc=example,dc=com" "dc=another,dc=com"
# #Local #
database bdb suffix "dc=example,dc=com" directory /usr/local/var/openldap-data/base/
rootdn "cn=manager,dc=example,dc=com" rootpw "secret"
index objectclass eq index cn,sn eq,sub
The ldif file I use to populate the local database...
dn: dc=example,dc=com dc: example description: Container for metadirectory objectClass: dcObject objectClass: organization o: example
dn: cn=Search user,dc=users,dc=example,dc=com cn: search user sn:search user objectclass: top objectclass: person objectclass: organizationalPerson userpassword: secret
Thanks for your help!
Drew
Andrew Graham ICT AgustaWestland UK Tel No: +44 (0) 1935 70 4421 andrew.graham@agustawestland.com
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----- "Andrew Graham" andrew.graham@agustawestland.com wrote:
*** Before acting on this email or opening any attachment you are advised to read the disclaimer at the end of this email ***
I've re-read my original message and it didn't make alot of sense. So here's take two!
I'm using back-meta to attempt to amalgamate several ldap servers into one single tree. This should cater for users that exist only in a local BDB database, and also for users with accounts in one of the target ldap servers. If I say 'local' or 'remote' user at any point, I'm referring to users stored in the local bdb database or a remote ldap server respectively. I shall refer to the local openldap server as the proxy server.
The meta database is subordinate to the local database. This allows me to have a base record for the entire directory.
Everything works perfectly for targets that don't require a bind before searching. For targets that do require a successful bind, I've been trying to use the 'idassert-bind' feature with mixed results. The following is a description of the behaviour I am trying to achieve:
If a local user binds to the proxy server, and performs a query with one or more targets in scope, then the proxy server should use predefined credentials to bind to and search only the targets in scope on behalf of the local user.
If a remote user binds to the proxy server, and performs a query affecting only the target where that user is stored, then the proxy server should bind to that target using the credentials supplied by the remote user. If there are any other targets in the scope of the query, openldap should not attempt to use the predefined credentials to bind to and search on that target.
To try to achieve this, I have placed all local users in their own branch of the tree, and set the 'idassert-authzFrom' for each target to match this branch only, thus preventing remote users from using the idassert feauture and barring them from querying other targets than their own.
Here is the first of two 'interesting' results. If I bind to the proxy server as a remote user with multiple targets in scope, the bind is proxied to the remote user's target correctly. The proxy then proceeds to attempt to bind to the other targets in scope using seemingly random names. Some examples (captured with wireshark) are '\270+1\b', '\250\202/\b\005', '\220\241\322\267\220\241\322\267\020' and 'x\267.\b'. The name changes every time, but each time no password is provided. The proxy will not attempt to search any of the targets after binding, even the target to which the user belongs.
I'm not sure I understand the purpose of the 'non-prescriptive' flag, but if I set it on each target (as Pierangelo suggested previously), the unusual behaviour changes. When binding with a remote user, the proxy will correctly bind to the target to which the remote user belongs using the remote users credentials. If another target is in scope, the proxy will attempt to bind to it without name or password. The proxy will proceed to search the targets. This is fine for my situation, but I would like to understand why this happens?
The second problem I'm having is with the local users. If the 'network-timeout' statement is used in the meta database definition, whenever a local user binds to the proxy and queries one or more of the target servers, the proxy will attempt to bind to the targets with the predefined name but with no password. If network-timeout is not specified, the proxy binds with both the predefined name and password to every target in scope. Is this behaviour intended or a bug?
I think your explanation is clear enough, provided some of the behaviours you describe are quite unexpected. There seems to be quite a few bugs in this feature. Unfortunately, I won't be able to work at it in the next few days, you'll need to wait at least until the end of next week.
p.
Ing. Pierangelo Masarati OpenLDAP Core Team
SysNet s.r.l. via Dossi, 8 - 27100 Pavia - ITALIA http://www.sys-net.it ----------------------------------- Office: +39 02 23998309 Mobile: +39 333 4963172 Fax: +39 0382 476497 Email: ando@sys-net.it -----------------------------------
openldap-software@openldap.org
-
Andrew Graham -
Pierangelo Masarati