Re: Fedora DS 1.0.2 Multiple Master SSL replication: empty bind DN...

Richard Megginson <rmeggins@xxxxxxxxxx> · Mon, 03 Jul 2006 08:26:12 -0600

Kevin McCarthy wrote:
Thanks again Richard, 

My attempt to determine why the bind DN remains as "" have still not located
the cause - though I guess that is due to this being my first usage and I
have merely missed the obvious!

To ensure that you are doing client cert auth, you can examine the access
log on the replication consumer - look for the connection and BIND from 
the supplier. If you're not sure what you're looking at, just post the 
relevant excerpts here.

I can see from the bind result that the initial "dn" is still the required: 

	"cn=nema2,ou=EDS,o=teligent,dc=co,c=uk"

..but the BIND dn remains as "", with the method as "sasl"?

Actually, the method is SASL/EXTERNAL, which means the BIND identity 
comes from somewhere else (in this case, the certificate).  So, dn="" is 
ignored since it is obtained from the certificate.

Consumer Access log file extract:

[03/Jul/2006:10:24:11 +0100] conn=11 fd=67 slot=67 SSL connection from
192.168.27.15 to 192.168.144.61

[03/Jul/2006:10:24:11 +0100] conn=11 SSL 256-bit AES; client
CN=nema2,OU=EDS,O=teligent,DC=co,C=uk; issuer CN=CAcertnema2

[03/Jul/2006:10:24:11 +0100] conn=11 SSL client bound as
cn=nema2,ou=EDS,o=teligent,dc=co,c=uk

[03/Jul/2006:10:24:11 +0100] conn=11 op=0 BIND dn="" method=sasl version=3
mech=EXTERNAL

All of this means that you are definitely doing client cert auth.  You 
say that the entry cn=nema2,ou=EDS,o=teligent,dc=co,c=uk exists on both 
servers (and cn=nema1 or cn=nema also)?  And you have this DN listed in 
the supplier DN in the replica configuration?  If so, then it could be 
that replication does not allow you to specify a supplier DN that lives 
in the replicated area.  What we usually recommend is that you create a 
replication pseudo user in the configuration naming context e.g.
dn: cn=repluser, cn=config
objectclass: person
sn: repluser
cn: repluser
userPassword: password

Then configure cert mapping to map the subjectDN in the cert to this 
user.  To make certmapping work, you may have to name the replication 
pseudo user something like cn=nema or cn=nema2 so you can use the 
attributes in the cert subjectDN to map to the pseudo user.  Then you 
will need to have the pseudo user DN as the supplier DN in the replica 
configuration.
[03/Jul/2006:10:24:11 +0100] conn=11 op=0 RESULT err=0 tag=97 nentries=0
etime=0 dn="cn=nema2,ou=EDS,o=teligent,dc=co,c=uk"

[03/Jul/2006:10:24:11 +0100] conn=11 op=1 SRCH base="" scope=0
filter="(objectClass=*)" attrs="supportedControl supportedExtension"
[03/Jul/2006:10:24:11 +0100] conn=11 op=1 RESULT err=0 tag=101 nentries=1
etime=0
[03/Jul/2006:10:24:11 +0100] conn=11 op=2 SRCH base="" scope=0
filter="(objectClass=*)" attrs="supportedControl supportedExtension"
[03/Jul/2006:10:24:11 +0100] conn=11 op=2 RESULT err=0 tag=101 nentries=1
etime=0
[03/Jul/2006:10:24:11 +0100] conn=11 op=3 EXT oid="2.16.840.1.113730.3.5.3"
name="Netscape Replication Start Session"
[03/Jul/2006:10:24:11 +0100] conn=11 op=3 RESULT err=0 tag=120 nentries=0
etime=0
[03/Jul/2006:10:24:12 +0100] conn=11 op=4 EXT oid="2.16.840.1.113730.3.5.3"
name="Netscape Replication Start Session"
[03/Jul/2006:10:24:12 +0100] conn=11 op=4 RESULT err=0 tag=120 nentries=0
etime=0
[03/Jul/2006:10:24:15 +0100] conn=11 op=5 EXT oid="2.16.840.1.113730.3.5.3"
name="Netscape Replication Start Session"
[03/Jul/2006:10:24:15 +0100] conn=11 op=5 RESULT err=0 tag=120 nentries=0
etime=0
[03/Jul/2006:10:24:19 +0100] conn=11 op=6 EXT oid="2.16.840.1.113730.3.5.3"
name="Netscape Replication Start Session"
[03/Jul/2006:10:24:19 +0100] conn=11 op=6 RESULT err=0 tag=120 nentries=0
etime=0
[03/Jul/2006:10:24:28 +0100] conn=11 op=8 EXT oid="2.16.840.1.113730.3.5.3"
name="Netscape Replication Start Session"
[03/Jul/2006:10:24:28 +0100] conn=11 op=8 RESULT err=0 tag=120 nentries=0
etime=0
[03/Jul/2006:10:24:34 +0100] conn=10 op=4 UNBIND
[03/Jul/2006:10:24:34 +0100] conn=10 op=4 fd=64 closed - U1
[03/Jul/2006:10:24:46 +0100] conn=11 op=10 EXT oid="2.16.840.1.113730.3.5.3"
name="Netscape Replication Start Session"
[03/Jul/2006:10:24:46 +0100] conn=11 op=10 RESULT err=0 tag=120 nentries=0
etime=0
[03/Jul/2006:10:25:08 +0100] conn=11 op=12 UNBIND
[03/Jul/2006:10:25:08 +0100] conn=11 op=12 fd=67 closed - U1

Consumer Error log file extract:

[03/Jul/2006:10:24:11 +0100] NSMMReplicationPlugin - conn=11 op=3
replica="ou=EDS,o=teligent,dc=
co,c=uk": Unable to acquire replica: error: permission denied
[03/Jul/2006:10:24:12 +0100] NSMMReplicationPlugin - conn=11 op=4
replica="ou=EDS,o=teligent,dc=co,c=uk": Unable to acquire replica: error:
permission denied
[03/Jul/2006:10:24:15 +0100] NSMMReplicationPlugin - conn=11 op=5
replica="ou=EDS,o=teligent,dc=co,c=uk": Unable to acquire replica: error:
permission denied
[03/Jul/2006:10:24:19 +0100] NSMMReplicationPlugin - conn=11 op=6
replica="ou=EDS,o=teligent,dc=co,c=uk": Unable to acquire replica: error:
permission denied
[03/Jul/2006:10:24:28 +0100] NSMMReplicationPlugin - conn=11 op=8
replica="ou=EDS,o=teligent,dc=co,c=uk": Unable to acquire replica: error:
permission denied
[03/Jul/2006:10:24:46 +0100] NSMMReplicationPlugin - conn=11 op=10
replica="ou=EDS,o=teligent,dc=co,c=uk": Unable to acquire replica: error:
permission denied
[03/Jul/2006:10:24:50 +0100] NSMMReplicationPlugin - agmt="cn=EDS from
Server 1" (nema2:636): Unable to acquire replica: permission denied. The
bind dn "" does not have permission to supply replication updates to the
replica. Will retry later.

Regards and thanks again,
Kevin

From: Richard Megginson <rmeggins@xxxxxxxxxx>
Subject: Re:  Fedora DS 1.0.2 Multiple Master
	SSL	replication: empty bind DN...
To: "General discussion list for the Fedora Directory server project."
	<fedora-directory-users@xxxxxxxxxx>
Message-ID: <44A51838.4040409@xxxxxxxxxx>
Content-Type: text/plain; charset="windows-1252"

Kevin McCarthy wrote:

Richard, thank you for your response!

hopefully whatever configuration mistake I made to cause a NULL bind 
DN will soon come to light

Dear List Members,

Release: *fedora-ds-1.0.2-1.RHEL3.i386.opt.rpm*

A typical replication error log entry now follows (seen repeatedly at

both fedora DS servers):

[28/Jun/2006:18:29:21 +0100] NSMMReplicationPlugin - agmt="cn=EDS from

server 2" (ukstatlap:636): Unable to acquire replica: permission

denied. The *bind dn ""* does not have permission to supply

replication updates to the replica. Will retry later.

Believe me, I have been investigating this one for 2 or 3 days now

(having just switched from OpenLDAP, since multiple master replication

is required) before sending this submission, just in case I missed a

configuration item or work-around, but unfortunately no luck (so far).

The only reference I can find for SSL Client Authentication based

Multiple Master replication (2 Linux RHEL 3 servers being used) that

supplies empty DNs, is the Windows specific entry (whose work-around I

tried anyway, but without success)_

Unable to acquire replica: permission denied. The bind dn "" does not

have permission to supply replication updates to the replica. Will

retry later.

To workaround the problem, after you modify and save the replication

schedule of an agreement, refresh the console, reconfigure the

connection settings (to SSL client authentication) for the agreement,

and save your changes.

http://www.redhat.com/docs/manuals/dir-server/release-notes/ds611relno

tes.html

The mutual _Current Supplier DNs_ are indeed set (cn=Replication

Manager,cn=replication,cn=config) and the corresponding directory

entries do exist.

The respective server certificates and CA certificates are installed,

with Subject DN entries loaded.

What are the SubjectDNs in the server certificates?

CN=<SERVERNAME>,OU=EDS,O=teligent,DC=co,C=uk

where <SERVERNAME> is the respective server name of the replicating 
servers e.g. nema2 rather than a full domain name.

I think this is ok, as long as your DNS (/etc/resolv.conf) configuration 
can resolve nema2.

The following will hopefully also be relevant:

1) The tree being replicated is OU=EDS,O=Teligent,DC=co,C=uk i.e. 
the Subject DN is within the replicated tree.

2) certutil was used to generate the server and CA certificates. 
Surprisingly (to me at least) the CA certificate was then listed in 
the "Server Certs" panel on the Directory Server Manage Certificates 
panel.

3) I loaded the ascii version of the other servers CA Certificate 
directly into the CA Certs panel.

4) All CA certificates have both the accept and make connection trusts 
ticked.

I do _not_ have Legacy Consumer enabled.

You don't need it.

CertMapping is also defined (though with a NULL DN being supplied, I

guess that will not be kicking in just yet, though there are entries

for the exact subject DN anyway.)

You might want to post your certmap.conf and see here - 
http://directory.fedora.redhat.com/wiki/Howto:CertMapping

I must admit that since the Bind DN was NULL I had not realized that 
certmapping would actually take affect.

If you are using client cert based auth (and not just username/password 
auth with SSL) then certmapping will be used. To ensure that you are 
doing client cert auth, you can examine the access log on the 
replication consumer - look for the connection and BIND from the 
supplier. If you're not sure what you're looking at, just post the 
relevant excerpts here.

...log file extract at the head.

I ensured that the exact subject DN of the server certificates 
corresponded to an actual directory entry (with the respective 
servers user certificate loaded), which I had thought would be 
matched without the need for a certmap configuration via the original 
default option, but I tried one anyway

certmap nema ou=EDS,o=teligent,dc=co,c=uk

I think this DN should correspond to the issuerDN (i.e. the subjectDN of 
your CA cert). But I don't think it's used for cert mapping.

nema:FilterComps cn

This means you must have one and only one entry called cn=nema2, ....., 
o=teligent,dc=co,c=uk somewhere in your tree.

...indeed, just the one.

nema:verifycert off

certmap default default

indeed one server still runs with the default certmap configuration 
to see if it made any difference, but both servers receive a NULL bind 
DN .

This leads me to believe it is not doing client cert auth. Also check 
the errors log for your supplier and consumer.

...extracts at the head.

When using simple authentication, with or without SSL, all is well

(although replication did require both servers to Initialize the

Consumer, I thought that only one was required e.g. ID 1 initializing

ID 2, but ID 2 then needed to initialize ID 1 before successful 2-way

replication was achieved).

That's odd. You should only need to initialize once one way.

indeed, but I guess that it can not do any harm, as the secondary 
server will not actually need to supply any further updates back to 
the primary server and it does at least make the mutual replication 
work for me  until the certificates took their toll

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