On Thu, 20 Mar 2014, Massimiliano Perrone (tirasa.net) wrote:
On 03/18/2014 05:26 PM, Alexander Bokovoy wrote:
On Tue, 18 Mar 2014, Massimiliano Perrone (example.com) wrote:
The difference between the two calls is on the last TGS_REQ; because the first one is on ldap/olmo.example....@example.com and it's OK whereas the second one is on HTTP/olmo.example....@example.com that returns a 401 (I suppose).

Where's the error?
Am I correct that you have a user connecting to HTTP/ebano.example.com
and then HTTP/ebano.example.com wants to talk to HTTP/olmo.example.com
using credentials of the user?

FreeIPA uses constraint delegation of the credentials, with the help of
S4U2Proxy extension. You need to allow HTTP/ebano.example.com to delegate
credentials to HTTP/olmo.example.com.

I have written an article how to do that:
https://vda.li/en/posts/2013/07/29/Setting-up-S4U2Proxy-with-FreeIPA/index.html



Hi Alexander, thanks for your reply.
I read carefully your interesting post and I follow it to delegate HTTP/ebano.example.com credentials to HTTP/olmo.example.com.

Now, two questions:
1) How can I check that my configuration, now is ok? Because this ldapsearch returns result: 0

ldapsearch -Y GSSAPI -H ldap://olmo.example.com -b "cn=s4u2proxy,cn=etc,dc=example,dc=com" "cn=ipa-http-delegation-targets" dn
You need to create these delegation entries yourself, like the article
says. Note that your app talks to IPA server's HTTP service, so create

dn: cn=ebano-http-delegation,cn=s4u2proxy,cn=etc,dc=example,dc=com
objectClass: ipaKrb5DelegationACL
objectClass: groupOfPrincipals
objectClass: top
cn: ebano-http-delegation
memberPrincipal: HTTP/ebano.example....@example.com
ipaAllowedTarget: 
cn=ebano-http-delegation-targets,cn=s4u2proxy,cn=etc,dc=example,dc=com

This entry says: "HTTP/ebano.example.com is allowed to delegate users'
credentials to whatever Kerberos principal is a member of
cn=ebano-http-delegation-targets group"

Now, this is the group:
dn: cn=ebano-http-delegation-targets,cn=s4u2proxy,cn=etc,dc=example,dc=com
objectClass: groupOfPrincipals
objectClass: top
cn: ebano-http-delegation-targets
memberPrincipal: HTTP/olomo.example....@example.com

With these two entries we would have HTTP/ebano.example.com allowed to
delegate users' credentials to HTTP/olomo.example.com

Hi Alexander, thanks for your patience.
I followed your suggestions but the result is always the same.

Trying with curl, of course, it works.

My doubt now is why curl generates this log on kerberos server

mar 20 10:22:20 olmo.example.com krb5kdc[5091](info): TGS_REQ (1 etypes {18}) 192.168.0.105: ISSUE: authtime 1395301975, etypes {rep=18 tkt=18 ses=18}, ad...@example.com for krbtgt/example....@example.com mar 20 10:22:21 olmo.example.com krb5kdc[5091](info): TGS_REQ (6 etypes {18 17 16 23 25 26}) 192.168.0.106: ISSUE: authtime 1395301975, etypes {rep=18 tkt=18 ses=18}, ad...@example.com for ldap/olmo.example....@example.com
This is effect of S4U extension working correctly.

whereas java generates this other one

mar 20 10:24:09 olmo.example.com krb5kdc[5091](info): AS_REQ (4 etypes {18 17 16 23}) 192.168.0.105: NEEDED_PREAUTH: HTTP/ebano.example....@example.com for krbtgt/example....@example.com, Additional pre-authentication required mar 20 10:24:09 olmo.example.com krb5kdc[5091](info): AS_REQ (4 etypes {18 17 16 23}) 192.168.0.105: ISSUE: authtime 1395307449, etypes {rep=18 tkt=18 ses=18}, HTTP/ebano.example....@example.com for krbtgt/example....@example.com mar 20 10:24:09 olmo.example.com krb5kdc[5091](info): TGS_REQ (6 etypes {18 17 16 23 1 3}) 192.168.0.105: ISSUE: authtime 1395307449, etypes {rep=18 tkt=18 ses=18}, HTTP/ebano.example....@example.com for HTTP/olmo.example....@example.com

As you can see, the first one uses admin on ldap service, the second one uses HTTP/ebano.example.com on HTTP service.
This means your Java application doesn't use S4U extension or doesn't
know about that.

Can I do the same call with Java?
At this point we need to set clear what Java are you using.

http://download.java.net/jdk8/docs/technotes/guides/security/jgss/jgss-features.html
tells that S4U extensions (we use S4U2Proxy here) was added in Java SE 8.

--
/ Alexander Bokovoy

_______________________________________________
Freeipa-devel mailing list
Freeipa-devel@redhat.com
https://www.redhat.com/mailman/listinfo/freeipa-devel

Reply via email to