KDC has no support for encryption type (14)

5
votes

I'm trying to implement SSO with kerberos using spring-security-kerberos extension.

I've created a keytab file and I get the following error when trying to access my webapp:

GSSException: Failure unspecified at GSS-API level (Mechanism level: Checksum failed)

I tried to test my keytab according to this post.

The keytab was created with the following command:

ktpass /out http-web.keytab /mapuser [email protected] /princ HTTP/[email protected] /pass myPass /ptype KRB5_NT_PRINCIPAL -crypto RC4-HMAC-NT /kvno 0

My krb5.conf is as follow

[libdefaults]
default_realm = MYDOMAIN.COM
permitted_enctypes =  aes256-cts arcfour-hmac-md5 aes128-cts rc4-hmac des3-cbc-sha1 des-cbc-md5 des-cbc-crc
default_tgs_enctypes = aes256-cts arcfour-hmac-md5 aes128-cts rc4-hmac des3-cbc-sha1 des-cbc-md5 des-cbc-crc
default_tkt_enctypes = aes256-cts arcfour-hmac-md5 aes128-cts rc4-hmac des3-cbc-sha1 des-cbc-md5 des-cbc-crc
kdc_timesync = 1
ccache_type = 4
forwardable = true
proxiable = true

[realms]
MYDOMAIN.COM = {
kdc = controller1.mydomain.com:88
kdc = controler2.mydomain.com:88
kdc = controller3.mydomain.com:88
admin_server = controller3.mydomain.com
default_domain = MYDOMAIN.COM
}

[domain_realm]
.mydomain.com = MYDOMAIN.COM
mydomain.com = MYDOMAIN.COM

[login]
krb4_convert = true
krb4_get_tickets = false

I get the following error:

 KDC has no support for encryption type (14)

I've tried enabling DES, AES-128 and AES-256 for the account of the SPN but it didn't solve the problem.

What am I missing here?

Thanks, Lior

4
active-directorykerberoskdc
In ktpass you're forcing a strange value of kvno: 0. Usually it's 1 or more. From Windows 2008 you may set crypto to All. – greenmarker
blogs.msdn.com/b/openspecification/archive/2011/05/31/… – greenmarker
As AD always increases 'key version' in entry corresponding to SPN when you use ktpass you have to check 'key version' first in AD and then use that +1 for '/kvno' for ktpass. However this is not related for this issue – Bernhard Thalmayr
Hey guys, Thanks for your help. I read that java may have problems with reading a keytab with kvno other than 0, so that's why I specifically set it to 0. Unfortunately I couldn't find this post again... Anyway, I tried it now without specifying kvno, and I get the same error. – Lior Chaga
I had to check the boxes for each of my spn accounts for "This account supports Kerberos AES 128 bit encryption" and "This account supports Kerberos AES 256 bit encryption". – J Maurer

4 Answers

6
votes

just bashed my head against the KrbException "KDC has no support for enryption type (14)" for several days in sequence. I have visited many places including some indepth MSDN blog posts (from Hongwei Sun, Sebastian Canevari) I cannot reference for lack of reputation.

Thanks, for your mention of kvno 0 and dsiabling DES it now also works on my side.

In the end it boiled down that I have my User Account setup with

userAccountControl: 0d66048 or 0x10200 which matches 0b10000001000000000 or ADS_UF_DONT_EXPIRE_PASSWD (0x00010000) and ADS_UF_NORMAL_ACCOUNT (0x00000200) but no UF_USE_DES_KEY_ONLY (0x200000) being set

and

msDS-SupportedEncryptionTypes: 0d16 or 0x10 which matches 0b10000 or AES256-CTS-HMAC-SHA1-96 (0x10) but no RC4-HMAC (0x04) being set.

ldapsearch -h masterdc.localnet.org -D 'spn_hostname' -w '*password*' -b 'ou=Accounts,dc=localnet,dc=org' -s sub 'userPrincipalName=HTTP/[email protected]' distinguishedName servicePrincipalName userPrincipalName msDS-SupportedEncryptionTypes userAccountControl
# extended LDIF
#
# LDAPv3
# base <ou=Accounts,dc=localnet,dc=org> with scope subtree
# filter: userPrincipalName=HTTP/[email protected]
# requesting: distinguishedName servicePrincipalName userPrincipalName msDS-SupportedEncryptionTypes userAccountControl
#

# spn_hostname, DokSvc, Services, Accounts, localnet.org
dn: CN=spn_hostname,OU=DokSvc,OU=Services,OU=Accounts,DC=localnet,DC=org
distinguishedName: CN=spn_hostname,OU=DokSvc,OU=Services,OU=Accounts,DC=localnet,DC=org
userAccountControl: 66048
userPrincipalName: HTTP/[email protected]
servicePrincipalName: HTTP/hostname.localnet.org
servicePrincipalName: HTTP/[email protected]
msDS-SupportedEncryptionTypes: 16

# search result
search: 2
result: 0 Success

# numResponses: 2
# numEntries: 1

With this and the following in my /etc/krb5.conf I can reproducably provoke "KrbException KDC has no support for enryption type (14)" when removing rc4-hmac from the default_tkt_enctypes.

/etc/krb5.conf:

[logging]
  default = FILE:/var/log/krb5libs.log
  kdc = FILE:/var/log/krb5kdc.log
  admin_server = FILE:/var/log/kadmind.log
[libdefaults]
  default_realm = LOCALNET.DE
  default_tkt_enctypes = aes256-cts
  default_tgs_enctypes = aes256-cts
  permitted_enctypes = aes256-cts
[realms]
LOCALNET.ORG = {
  kdc = masterdc.localnet.org:88
  admin_server = masterdc.localnet.org
  default_domain = LOCALNET.ORG
}
[domain_realm]
  .localnet.org = LOCALNET.ORG
  localnet.org = LOCALNET.ORG
[appdefaults]
  autologin = true
  forward = true
  forwardable = true
  encrypt = true

However if you change it to default_tkt_enctypes = aes256-cts rc4-hmac it will succeed.

Note that you can also leave out specifying the default_tkt_enctypes directive in /etc/krb5.conf, in order to make it work. 

Using builtin default etypes for default_tkt_enctypes
default etypes for default_tkt_enctypes: 18 17 16 23.

It therefor looks like Windows Server 2008 SP2 Active Directory does explicitly require RC4-HMAC in the Pre-Authentication phase:

         PA-ETYPE-INFO2 etype = 23, salt = null, s2kparams = null

I have updated JCE 1.8.0 policy files within my JDK's jre/lib/security folder in order for AES256 to be supported.

Kind regards, Stefan

The enctypes are specified under

Kerberos Parameters http://www.iana.org/assignments/kerberos-parameters/kerberos-parameters.xhtml

etype   encryption type     Reference
1   des-cbc-crc     [RFC3961]
3   des-cbc-md5     [RFC3961]
17  aes128-cts-hmac-sha1-96     [RFC3962]
18  aes256-cts-hmac-sha1-96     [RFC3962]
23  rc4-hmac    [RFC4757]

Failure:

java -cp /somepath/krb5.jar -Dsun.security.krb5.debug=true sun.security.krb5.internal.tools.Kinit -k -t /somepath/spn_hostname.keytab HTTP/[email protected]
>>>KinitOptions cache name is /tmp/krb5cc_723
Principal is HTTP/[email protected]
>>> Kinit using keytab
>>> Kinit keytab file name: /somepath/spn_hostname.keytab
Java config name: null
LSA: Found Ticket
LSA: Made NewWeakGlobalRef
LSA: Found PrincipalName
LSA: Made NewWeakGlobalRef
LSA: Found DerValue
LSA: Made NewWeakGlobalRef
LSA: Found EncryptionKey
LSA: Made NewWeakGlobalRef
LSA: Found TicketFlags
LSA: Made NewWeakGlobalRef
LSA: Found KerberosTime
LSA: Made NewWeakGlobalRef
LSA: Found String
LSA: Made NewWeakGlobalRef
LSA: Found DerValue constructor
LSA: Found Ticket constructor
LSA: Found PrincipalName constructor
LSA: Found EncryptionKey constructor
LSA: Found TicketFlags constructor
LSA: Found KerberosTime constructor
LSA: Finished OnLoad processing
Native config name: C:\Windows\krb5.ini
Loaded from native config
>>> Kinit realm name is LOCALNET.ORG
>>> Creating KrbAsReq
>>> KrbKdcReq local addresses for hostname.localnet.org are:

        hostname.localnet.org/192.168.1.2
IPv4 address
>>> KdcAccessibility: reset
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 64; type: 1
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 64; type: 3
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 72; type: 23
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 88; type: 18
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 72; type: 17
Looking for keys for: HTTP/[email protected]
Added key: 17version: 0
Added key: 18version: 0
Added key: 23version: 0
Found unsupported keytype (3) for HTTP/[email protected]
Found unsupported keytype (1) for HTTP/[email protected]
default etypes for default_tkt_enctypes: 18.
>>> KrbAsReq creating message
>>> KrbKdcReq send: kdc=masterdc.localnet.org UDP:88, timeout=30000, number of retries =3, #bytes=216
>>> KDCCommunication: kdc=masterdc.localnet.org UDP:88, timeout=30000,Attempt =1, #bytes=216
>>> KrbKdcReq send: #bytes read=194
>>>Pre-Authentication Data:
         PA-DATA type = 19
         PA-ETYPE-INFO2 etype = 18, salt = LOCALNET.ORGHTTPhostname.localnet.org, s2kparams = null

>>>Pre-Authentication Data:
         PA-DATA type = 2
         PA-ENC-TIMESTAMP
>>>Pre-Authentication Data:
         PA-DATA type = 16

>>>Pre-Authentication Data:
         PA-DATA type = 15

>>> KdcAccessibility: remove masterdc.localnet.org:88
>>> KDCRep: init() encoding tag is 126 req type is 11
>>>KRBError:
         sTime is Tue Jan 17 18:49:14 CET 2017 1484675354000
         suSec is 822386
         error code is 25
         error Message is Additional pre-authentication required
         sname is krbtgt/[email protected]
         eData provided.
         msgType is 30
>>>Pre-Authentication Data:
         PA-DATA type = 19
         PA-ETYPE-INFO2 etype = 18, salt = LOCALNET.ORGHTTPhostname.localnet.org, s2kparams = null

>>>Pre-Authentication Data:
         PA-DATA type = 2
         PA-ENC-TIMESTAMP
>>>Pre-Authentication Data:
         PA-DATA type = 16

>>>Pre-Authentication Data:
         PA-DATA type = 15

KrbAsReqBuilder: PREAUTH FAILED/REQ, re-send AS-REQ
default etypes for default_tkt_enctypes: 18.
Looking for keys for: HTTP/[email protected]
Added key: 17version: 0
Added key: 18version: 0
Added key: 23version: 0
Found unsupported keytype (3) for HTTP/[email protected]
Found unsupported keytype (1) for HTTP/[email protected]
Looking for keys for: HTTP/[email protected]
Added key: 17version: 0
Added key: 18version: 0
Added key: 23version: 0
Found unsupported keytype (3) for HTTP/[email protected]
Found unsupported keytype (1) for HTTP/[email protected]
default etypes for default_tkt_enctypes: 18.
>>> EType: sun.security.krb5.internal.crypto.Aes256CtsHmacSha1EType
>>> KrbAsReq creating message
>>> KrbKdcReq send: kdc=masterdc.localnet.org UDP:88, timeout=30000, number of retries =3, #bytes=305
>>> KDCCommunication: kdc=masterdc.localnet.org UDP:88, timeout=30000,Attempt =1, #bytes=305
>>> KrbKdcReq send: #bytes read=93
>>> KdcAccessibility: remove masterdc.localnet.org:88
>>> KDCRep: init() encoding tag is 126 req type is 11
>>>KRBError:
         sTime is Tue Jan 17 18:49:14 CET 2017 1484675354000
         suSec is 25186
         error code is 14
         error Message is KDC has no support for encryption type
         sname is krbtgt/[email protected]
         msgType is 30
Exception: krb_error 14 KDC has no support for encryption type (14) KDC has no support for encryption type
KrbException: KDC has no support for encryption type (14)
        at sun.security.krb5.KrbAsRep.<init>(Unknown Source)
        at sun.security.krb5.KrbAsReqBuilder.send(Unknown Source)
        at sun.security.krb5.KrbAsReqBuilder.action(Unknown Source)
        at sun.security.krb5.internal.tools.Kinit.<init>(Unknown Source)
        at sun.security.krb5.internal.tools.Kinit.main(Unknown Source)
Caused by: KrbException: Identifier doesn't match expected value (906)
        at sun.security.krb5.internal.KDCRep.init(Unknown Source)
        at sun.security.krb5.internal.ASRep.init(Unknown Source)
        at sun.security.krb5.internal.ASRep.<init>(Unknown Source)
        ... 5 more

Success:

java -cp /home/wls0/webdav/krb5.jar -Dsun.security.krb5.debug=true sun.security.krb5.internal.tools.Kinit -k -t /somepath/spn_hostname.keytab HTTP/[email protected]
>>>KinitOptions cache name is /tmp/krb5cc_723
Principal is HTTP/[email protected]
>>> Kinit using keytab
>>> Kinit keytab file name: /somepath/spn_hostname.keytab
Java config name: null
Native config name: /etc/krb5.conf
Loaded from native config
>>> Kinit realm name is LOCALNET.ORG
>>> Creating KrbAsReq
>>> KrbKdcReq local addresses for hostname.localnet.org are:

        hostname.localnet.org/192.168.1.2
IPv4 address
>>> KdcAccessibility: reset
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 64; type: 1
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 64; type: 3
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 72; type: 23
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 88; type: 18
>>> KeyTabInputStream, readName(): LOCALNET.ORG
>>> KeyTabInputStream, readName(): HTTP
>>> KeyTabInputStream, readName(): hostname.localnet.org
>>> KeyTab: load() entry length: 72; type: 17
Looking for keys for: HTTP/[email protected]
Added key: 17version: 0
Added key: 18version: 0
Added key: 23version: 0
Found unsupported keytype (3) for HTTP/[email protected]
Found unsupported keytype (1) for HTTP/[email protected]
default etypes for default_tkt_enctypes: 23 18.
>>> KrbAsReq creating message
>>> KrbKdcReq send: kdc=masterdc.localnet.org UDP:88, timeout=30000, number of retries =3, #bytes=180
>>> KDCCommunication: kdc=masterdc.localnet.org UDP:88, timeout=30000,Attempt =1, #bytes=180
>>> KrbKdcReq send: #bytes read=201
>>>Pre-Authentication Data:
         PA-DATA type = 19
         PA-ETYPE-INFO2 etype = 18, salt = LOCALNET.ORGHTTPhostname.localnet.org, s2kparams = null
         PA-ETYPE-INFO2 etype = 23, salt = null, s2kparams = null

>>>Pre-Authentication Data:
         PA-DATA type = 2
         PA-ENC-TIMESTAMP
>>>Pre-Authentication Data:
         PA-DATA type = 16

>>>Pre-Authentication Data:
         PA-DATA type = 15

>>> KdcAccessibility: remove masterdc.localnet.org
>>> KDCRep: init() encoding tag is 126 req type is 11
>>>KRBError:
         sTime is Tue Jan 17 19:11:56 CET 2017 1484676716000
         suSec is 116308
         error code is 25
         error Message is Additional pre-authentication required
         sname is krbtgt/[email protected]
         eData provided.
         msgType is 30
>>>Pre-Authentication Data:
         PA-DATA type = 19
         PA-ETYPE-INFO2 etype = 18, salt = LOCALNET.ORGHTTPhostname.localnet.org, s2kparams = null
         PA-ETYPE-INFO2 etype = 23, salt = null, s2kparams = null

>>>Pre-Authentication Data:
         PA-DATA type = 2
         PA-ENC-TIMESTAMP
>>>Pre-Authentication Data:
         PA-DATA type = 16

>>>Pre-Authentication Data:
         PA-DATA type = 15

KrbAsReqBuilder: PREAUTH FAILED/REQ, re-send AS-REQ
default etypes for default_tkt_enctypes: 23 18.
Looking for keys for: HTTP/[email protected]
Added key: 17version: 0
Added key: 18version: 0
Added key: 23version: 0
Found unsupported keytype (3) for HTTP/[email protected]
Found unsupported keytype (1) for HTTP/[email protected]
Looking for keys for: HTTP/[email protected]
Added key: 17version: 0
Added key: 18version: 0
Added key: 23version: 0
Found unsupported keytype (3) for HTTP/[email protected]
Found unsupported keytype (1) for HTTP/[email protected]
default etypes for default_tkt_enctypes: 23 18.
>>> EType: sun.security.krb5.internal.crypto.Aes256CtsHmacSha1EType
>>> KrbAsReq creating message
>>> KrbKdcReq send: kdc=masterdc.localnet.org UDP:88, timeout=30000, number of retries =3, #bytes=269
>>> KDCCommunication: kdc=masterdc.localnet.org UDP:88, timeout=30000,Attempt =1, #bytes=269
>>> KrbKdcReq send: #bytes read=94
>>> KrbKdcReq send: kdc=masterdc.localnet.org TCP:88, timeout=30000, number of retries =3, #bytes=269
>>> KDCCommunication: kdc=masterdc.localnet.org TCP:88, timeout=30000,Attempt =1, #bytes=269
>>>DEBUG: TCPClient reading 1615 bytes
>>> KrbKdcReq send: #bytes read=1615
>>> KdcAccessibility: remove masterdc.localnet.org
Looking for keys for: HTTP/[email protected]
Added key: 17version: 0
Added key: 18version: 0
Added key: 23version: 0
Found unsupported keytype (3) for HTTP/[email protected]
Found unsupported keytype (1) for HTTP/[email protected]
>>> EType: sun.security.krb5.internal.crypto.Aes256CtsHmacSha1EType
>>> KrbAsRep cons in KrbAsReq.getReply HTTP/hostname.localnet.org
New ticket is stored in cache file /tmp/krb5cc_723

PS: You might want to extract the Kerberos 5 Tools from a Windows JDK because Oracle have removed it from the JDK 1.6 onwards. This gives you additional debug output on Linux platform with the Parameter (-Dsun.security.krb5.debug=true).

mkdir sun.security.krb5
cd sun.security.krb5
"C:\Oracle\Java\jdk1.8.0_112\bin\jar.exe" -xf C:\Oracle\Java\jre1.8.0_112\lib\rt.jar sun\security\krb5
"C:\Oracle\Java\jdk1.8.0_112\bin\jar.exe" -cf krb5.jar sun\security\krb5
dir

This works around JDK-6910497 : Kinit class missing http://bugs.java.com/bugdatabase/view_bug.do?bug_id=6910497

4
votes

Finally got it working: When implementing kerberos authentication for Oracle JDK 6, one should use RC4-HMAC encryption, and so the DES and AES support should be disabled for the user account.

Why did I check them in the first place is another story....

1
votes

The solution for me was to check these two options of the AD user via the Active Directory Users and Computers tool on the account tab:

enter image description here

0
votes

What helped in my case was the switch

ktpass ... -crypto all ...

and I commented all of these in krb5.conf:

# default_tkt_enctypes = ...
# default_tgs_enctypes = ...
# permitted_enctypes   = ...

I guess it's default setup with rc4-hmac encoding that's most compatible.

No special settings were needed in Active Directory on my SPN account.

Windows Server 2008, Weblogic 10.3.6, Oracle JDK 1.7