I’m not sure about this and wonder it may not work. But I have no idea for now how to extract the TGT correctly. encKdcRepPart = new EncAsRepPart(); encKdcRepPart.setAuthTime(cred.getAuthTime()); encKdcRepPart.setCaddr(cred.getClientAddresses()); encKdcRepPart.setEndTime(cred.getEndTime()); encKdcRepPart.setFlags(cred.getTicketFlags()); encKdcRepPart.setKey(cred.getKey()); encKdcRepPart.setRenewTill(cred.getRenewTill()); encKdcRepPart.setSname(cred.getServerName()); encKdcRepPart.setSrealm(cred.getServerName().getRealm()); encKdcRepPart.setStartTime(cred.getStartTime());
From: Christopher Lamb [mailto:christopher.l...@ch.ibm.com] Sent: Tuesday, May 09, 2017 1:34 PM To: kerby@directory.apache.org Subject: Re: Using Kerby kerb-client as an alternative for GSS-API.... Sgt Request fails Hi all I can now retrieve the Tgt from the creds-cache, and request a Sgt. However I am now bouncing between 2 errors. "ERR BAD OPTION" and "ERR GENERIC". If I create the Tgt with the clientPrincipal, the request is rejected by the KDC with "ERR BAD OPTION". Examining the request with Wireshark shows a cname element in the req-body. This is not present in successful requests via GSS-API. cname name-type: kRB5-NT-PRINCIPAL (1) cname-string: 1 item CNameString: lamb The KDC log shows "TGT NOT PROXIABLE:" for the failed request. On the other hand, if I fill the clientPrincipal on the Tgt with null the request is rejected by the KDC with "ERR GENERIC". The cname element is no longer present in the request body (which now looks identical that made by GSS-API). The KDC logs show "ASN.1 structure is missing a required field". I suspect this refers to the encrypted "app-req/authenticator/cname", which debugging shows is now null! private TgtTicket retrieveCachedTicket(File ccacheFile) throws KrbException { Ticket ticket = null; PrincipalName clientPrincipal = null; EncAsRepPart encKdcRepPart = null; if (ccacheFile.exists() && ccacheFile.canRead()) { CredentialCache cCache = new CredentialCache(); try { cCache.load(ccacheFile); List<Credential> credentials = cCache.getCredentials(); for (Credential cred : credentials) { //we only want a tgt if (cred.getServerName().toString().startsWith("krbtgt")) { ticket = cred.getTicket(); clientPrincipal = cred.getClientName(); encKdcRepPart = new EncAsRepPart(); encKdcRepPart.setAuthTime(cred.getAuthTime()); encKdcRepPart.setCaddr(cred.getClientAddresses()); encKdcRepPart.setEndTime(cred.getEndTime()); encKdcRepPart.setFlags(cred.getTicketFlags()); encKdcRepPart.setKey(cred.getKey()); encKdcRepPart.setRenewTill(cred.getRenewTill()); encKdcRepPart.setSname(cred.getServerName()); encKdcRepPart.setSrealm(cred.getServerName().getRealm()); encKdcRepPart.setStartTime(cred.getStartTime()); } } } catch (IOException e) { throw new KrbException("Failed to load credentials", e); } } else { throw new IllegalArgumentException("Invalid ccache file, " + "does not exist, or is not readable: " + ccacheFile.getAbsolutePath()); } return new TgtTicket(ticket, encKdcRepPart, clientPrincipal); } private void getKerbyServiceTicket() { try { File confFileDir = new File("/home/lamb/OTMS/kerberosTesting/"); KrbClient krbClient = new KrbClient(confFileDir); krbClient.setKdcHost("kdc.acme.com"); krbClient.setAllowUdp(true); krbClient.setAllowTcp(true); krbClient.setKdcUdpPort(88); krbClient.setKdcTcpPort(88); krbClient.init(); File credsCache = new File("/tmp/krb5cc_9337"); TgtTicket tgtTicket = retrieveCachedTicket(credsCache); KOptions requestOptions = new KOptions(); requestOptions.add(KrbKdcOption.PROXIABLE, true); requestOptions.add(KrbKdcOption.FORWARDABLE); requestOptions.add(KrbKdcOption.CANONICALIZE, true); requestOptions.add(KrbKdcOption.RENEWABLE_OK, false); requestOptions.add(KrbOption.USE_TGT, tgtTicket); requestOptions.add(KrbOption.SERVER_PRINCIPAL, "HTTP/app-srv.acme....@acme.com<mailto:HTTP/app-srv.acme....@acme.com>"); SgtTicket sgtTicket = krbClient.requestSgt(requestOptions); } catch (KrbException e) { // TODO Auto-generated catch block e.printStackTrace(); } } Rejected Request "BAD OPTION": tgs-req pvno: 5 msg-type: krb-tgs-req (12) padata: 1 item PA-DATA PA-TGS-REQ padata-type: kRB5-PADATA-TGS-REQ (1) padata-value: 6e82023b30820237a003020105a10302010ea20703050000... ap-req pvno: 5 msg-type: krb-ap-req (14) Padding: 0 ap-options: 00000000 0... .... = reserved: False .0.. .... = use-session-key: False ..0. .... = mutual-required: False ticket tkt-vno: 5 realm: ACME.COM sname name-type: kRB5-NT-PRINCIPAL (1) sname-string: 2 items SNameString: krbtgt SNameString: ACME.COM enc-part etype: eTYPE-AES256-CTS-HMAC-SHA1-96 (18) kvno: 1 cipher: c2da50b960fdfdc44e098ee243f0aa698cfad82b8867fb98... authenticator etype: eTYPE-AES256-CTS-HMAC-SHA1-96 (18) cipher: 5e944cb16b72c6cb12b830b91e83ca84b3b7eadfb364e7da... req-body Padding: 0 kdc-options: 50010000 (forwardable, proxiable, canonicalize) 0... .... = reserved: False .1.. .... = forwardable: True ..0. .... = forwarded: False ...1 .... = proxiable: True .... 0... = proxy: False .... .0.. = allow-postdate: False .... ..0. = postdated: False .... ...0 = unused7: False 0... .... = renewable: False .0.. .... = unused9: False ..0. .... = unused10: False ...0 .... = opt-hardware-auth: False .... ..0. = request-anonymous: False .... ...1 = canonicalize: True 0... .... = constrained-delegation: False ..0. .... = disable-transited-check: False ...0 .... = renewable-ok: False .... 0... = enc-tkt-in-skey: False .... ..0. = renew: False .... ...0 = validate: False cname name-type: kRB5-NT-PRINCIPAL (1) cname-string: 1 item CNameString: lamb realm: ACME.COM sname name-type: kRB5-NT-PRINCIPAL (1) sname-string: 2 items SNameString: HTTP SNameString: app-srv.acme.com from: 2017-05-09 04:42:12 (UTC) till: 2017-05-09 12:42:12 (UTC) nonce: 589063260 etype: 3 items ENCTYPE: eTYPE-ARCFOUR-HMAC-MD5 (23) ENCTYPE: eTYPE-AES256-CTS-HMAC-SHA1-96 (18) ENCTYPE: eTYPE-AES128-CTS-HMAC-SHA1-96 (17) Thanks Chris [Inactive hide details for Christopher Lamb---08/05/2017 18:43:05---Hi Kai With the following code I can successfully retrieve a]Christopher Lamb---08/05/2017 18:43:05---Hi Kai With the following code I can successfully retrieve a TGT from my existing From: Christopher Lamb/Switzerland/IBM@IBMCH To: kerby@directory.apache.org<mailto:kerby@directory.apache.org> Date: 08/05/2017 18:43 Subject: Re: Using Kerby kerb-client as an alternative for GSS-API for Kerberos Single Sign On. ________________________________ Hi Kai With the following code I can successfully retrieve a TGT from my existing credential cache and use it to request a service ticket!. Unfortunately the Service Ticket Request is currently failing with "KDC cannot accommodate requested option". private TgtTicket retrieveCachedTicket(File ccacheFile) throws KrbException { Ticket ticket = null; PrincipalName clientPrincipal = null; EncAsRepPart encKdcRepPart = null; if (ccacheFile.exists() && ccacheFile.canRead()) { CredentialCache cCache = new CredentialCache(); try { cCache.load(ccacheFile); List<Credential> credentials = cCache.getCredentials(); for (Credential cred : credentials) { //we only want a tgt if (cred.getServerName().toString().startsWith("krbtgt")) { ticket = cred.getTicket(); clientPrincipal = cred.getClientName(); encKdcRepPart = new EncAsRepPart(); encKdcRepPart.setAuthTime(cred.getAuthTime()); encKdcRepPart.setCaddr(cred.getClientAddresses()); encKdcRepPart.setEndTime(cred.getEndTime()); encKdcRepPart.setFlags(cred.getTicketFlags()); encKdcRepPart.setKey(cred.getKey()); //encKdcRepPart.setKeyExpiration(); //no method to get from cred //encKdcRepPart.setLastReq(); //no method to get from cred //encKdcRepPart.setNonce(); //no method to get from cred encKdcRepPart.setRenewTill(cred.getRenewTill()); encKdcRepPart.setSname(cred.getServerName()); encKdcRepPart.setSrealm(cred.getServerName().getRealm()); encKdcRepPart.setStartTime(cred.getStartTime()); } } } catch (IOException e) { throw new KrbException("Failed to load credentials", e); } } else { throw new IllegalArgumentException("Invalid ccache file, " + "does not exist, or is not readable: " + ccacheFile.getAbsolutePath()); } return new TgtTicket(ticket, encKdcRepPart, clientPrincipal); } private void getKerbyServiceTicket() { try { File confFileDir = new File("/home/lamb/OTMS/kerberosTesting/"); KrbClient krbClient = new KrbClient(confFileDir); krbClient.setKdcHost("kdc.acme.com"); krbClient.setAllowUdp(true); krbClient.setAllowTcp(true); krbClient.setKdcUdpPort(88); krbClient.setKdcTcpPort(88); krbClient.init(); File credsCache = new File("/tmp/krb5cc_9337"); TgtTicket tgtTicket = retrieveCachedTicket(credsCache); KOptions requestOptions = new KOptions(); requestOptions.add(KrbKdcOption.PROXIABLE); requestOptions.add(KrbKdcOption.FORWARDABLE); requestOptions.add(KrbKdcOption.RENEWABLE_OK); requestOptions.add(KrbOption.USE_TGT, tgtTicket); requestOptions.add(KrbOption.SERVER_PRINCIPAL, "HTTP/app-srv.acme....@acme.com<mailto:HTTP/app-srv.acme....@acme.com>"); SgtTicket sgtTicket = krbClient.requestSgt(requestOptions); } catch (KrbException e) { // TODO Auto-generated catch block e.printStackTrace(); } } Below are extracts from the KDC logs for a failed request from my kerb-client code above, and 2 successful requests from GSS-API Rejected request from Java kerby kerb-client 94117:May 08 17:16:26 kdc.acme.com krb5kdc[2177](info): TGS_REQ (3 etypes {23 18 17}) 9.164.27.87: TGT NOT PROXIABLE: authtime 0, l...@acme.com<mailto:l...@acme.com> for HTTP/app-srv.acme....@acme.com<mailto:HTTP/app-srv.acme....@acme.com>, KDC can't fulfill requested option Successful request from Java GSS-API 77320:May 07 08:51:56 kdc.acme.com krb5kdc[2177](info): TGS_REQ (4 etypes {18 17 16 23}) 9.83.236.240: ISSUE: authtime 1494139147, etypes {rep=18 tkt=18 ses=18}, l...@acme.com<mailto:l...@acme.com> for HTTP/app-srv.acme....@acme.com<mailto:HTTP/app-srv.acme....@acme.com> Successful request from Python GSS-API 94221:May 08 17:24:18 kdc.acme.com krb5kdc[2177](info): TGS_REQ (8 etypes {18 17 20 19 16 23 25 26}) 9.164.27.87: ISSUE: authtime 1494256163, etypes {rep=18 tkt=18 ses=18}, l...@acme.com<mailto:l...@acme.com> for HTTP/app-srv.acme....@acme.com<mailto:HTTP/app-srv.acme....@acme.com> Cheers Chris "Zheng, Kai" ---08/05/2017 14:32:29---Got your point. Please read credential cache utility codes and see if any API doing so. Sent from iP From: "Zheng, Kai" <kai.zh...@intel.com<mailto:kai.zh...@intel.com>> To: "kerby@directory.apache.org<mailto:kerby@directory.apache.org>" <kerby@directory.apache.org<mailto:kerby@directory.apache.org>> Date: 08/05/2017 14:32 Subject: Re: Using Kerby kerb-client as an alternative for GSS-API for Kerberos Single Sign On. ________________________________ Got your point. Please read credential cache utility codes and see if any API doing so. Sent from iPhone 在 2017年5月8日，下午8:13，Christopher Lamb <christopher.l...@ch.ibm.com<mailto:christopher.l...@ch.ibm.com>> 写道： Hi Kai Browsing further through the kerby code, I think I need the opposite of KrbClientBase.storeTicket(): for instance a " Public TgtTicket retrieveCachedTicket(File ccacheFile)" Let me see if I can knock something together based on storeTicket().... Cheers Chris [Inactive hide details for "Zheng, Kai" ---08/05/2017 13:09:19---If I remember correctly, it first generates a cache with a TGT,]"Zheng, Kai" ---08/05/2017 13:09:19---If I remember correctly, it first generates a cache with a TGT, then do the login test with the tick From: "Zheng, Kai" <kai.zh...@intel.com<mailto:kai.zh...@intel.com>> To: "kerby@directory.apache.org<mailto:kerby@directory.apache.org>" <kerby@directory.apache.org<mailto:kerby@directory.apache.org>> Date: 08/05/2017 13:09 Subject: RE: Using Kerby kerb-client as an alternative for GSS-API for Kerberos Single Sign On. ________________________________ If I remember correctly, it first generates a cache with a TGT, then do the login test with the ticket cache. In your case, you would need to know where is the cache file and point it to Kerby client, as the test did. Regards, Kai From: Christopher Lamb [mailto:christopher.l...@ch.ibm.com] Sent: Monday, May 08, 2017 7:05 PM To: kerby@directory.apache.org<mailto:kerby@directory.apache.org> Subject: RE: Using Kerby kerb-client as an alternative for GSS-API for Kerberos Single Sign On. Hi Kai Thanks, example code is always best. TicketCacheLoginTest looks like part of the answer, especially the storeTicket() function. However (unless I have completely misread the test-case), the TGT is not retrieved from the cache, it is only stored there. In my Single-Sign-On case, the user already has a TGT, which was obtained on log in to the workstation (or by kinit), prior to starting my java client. I am assuming it should be possible for kerby to use the existing TGT. Cheers Chris [Inactive hide details for "Zheng, Kai" ---08/05/2017 12:45:22---Hi Chris, Both dev list should be OK as Kerby folks are also in]"Zheng, Kai" ---08/05/2017 12:45:22---Hi Chris, Both dev list should be OK as Kerby folks are also in the parent one. From: "Zheng, Kai" <kai.zh...@intel.com<mailto:kai.zh...@intel.com><mailto:kai.zh...@intel.com>> To: "kerby@directory.apache.org<mailto:kerby@directory.apache.org><mailto:kerby@directory.apache.org>" <kerby@directory.apache.org<mailto:kerby@directory.apache.org><mailto:kerby@directory.apache.org>> Date: 08/05/2017 12:45 Subject: RE: Using Kerby kerb-client as an alternative for GSS-API for Kerberos Single Sign On. ________________________________ Hi Chris, Both dev list should be OK as Kerby folks are also in the parent one. I haven't read your details fully (will do it later), but would make sure if you have already checked out the test of TicketCacheLoginTest in the kerby code base. In one word, Kerby client surely can consume and use a credential cache generated by other tools like MIT kinit. If you see any issue, please report it. Regards, Kai -----Original Message----- From: Christopher Lamb [mailto:christopher.l...@ch.ibm.com] Sent: Monday, May 08, 2017 5:09 PM To: kerby@directory.apache.org<mailto:kerby@directory.apache.org><mailto:kerby@directory.apache.org> Subject: Using Kerby kerb-client as an alternative for GSS-API for Kerberos Single Sign On. Hi all I hope this is the appropriate mailing list for this type of question. Or would it be better on the Directory Developers’ list? I am considering using Kerby kerb-client as an alternative to Java GSS-API for a Java client application in a Kerberos single sign on environment. In my proof of concept setup I am using FreeIPA clients and servers. When the user logs on to his workstation he is authenticated by the FreeIPA KDC, and gets a TGT which is cached in the default credentials cache. When he wishes to access services from the application server (which is a Service Principal), the TGT in the credentials cache is used to get a Service Ticket, which should also be cached in the credentials cache for future use. With a throwaway Python GSS-API client this worked perfectly. "klist" shows both the TGT and the SGT in the credentials cache. But trying to do the same thing with Java GSS-API I ran into problems. While the Client is able to retrieve a Service Ticket, and thus login to the Service Principal, the SGT is not cached. Thus every request to the Service Principal requires KDC interaction. Not good. In my search for alternatives, I came across Kerby kerb-client, and am experimenting with it, but so far without success despite much debugging and scanning of Kerby code. Here is the question: Can the Kerby kerb-client be configured to access an existing Kerberos credential cache (as opposed to a KeyTab), and to use the TGT ticket within, and to cache new service tickets? In this case the existing credentials cache is from So far I have found no config to do so. Searching through the Kerby code I find references to things like ‘credCache’, ‘KRB5_CACHE’, ‘ARMOR_CACHE’. However in AbstractInternalKrbClient.requestTGT() I can’t find any USE_xxx options that seem appropriate for using a credentials cache. Have I missed something obvious? If so, which options should I be configuring? Thanks Chris
