SPNEGO in tomcat always prompting password

Question

My SPNEGO configuration seems to not work and always prompts for a password in my tomcat8.

Installation/Configuration SPNEGO install guide

I added the library spnego-r9.jar to the "tomcat\lib"-folder. Added the.conf files as well. Here the krb5.conf:

[libdefaults]
dns_lookup_realm = false
ticket_lifetime = 24h
renew_lifetime = 7d
forwardable = true
rdns = false
default_ccache_name = KEYRING:persistent:%{uid}
udp_preference_limit = 1
default_realm=EXAMPLE.COM
default_tkt_enctypes = aes256-cts aes128-cts des3-cbc-sha1 des-cbc-md5 des-cbc-crc aes256-cts- 
hmac-sha1-96 rc4-hmac
default_tgs_enctypes = aes256-cts aes128-cts des3-cbc-sha1 des-cbc-md5 des-cbc-crc aes256-cts- 
hmac-sha1-96 rc4-hmac
permitted_enctypes =  aes256-cts aes128-cts des3-cbc-sha1 des-cbc-md5 des-cbc-crc aes256-cts- 
hmac-sha1-96 rc4-hmac

[realms]
EXAMPLE.COM = {
    default_domain=example.com
    kdc=dc2.example.com:88
}

[domain_realm]
.example.com=EXAMPLE.COM
example.com=EXAMPLE.COM

The SpnegoHttpFilter was then added to the web.xml. Last but not least I contacted our admins and added the following to the user registered in the SpnegoHttpFilter

setspn.exe -A HTTP/ourserver01.example.com/projectXY exampleUser
setspn.exe -A HTTP/ourserver01/projectXY exampleUser

The result is a password prompt even though my accessing user is logged in to the EXAMPLE.COM domain. To my knowledge this should not happen. I logged on to our server and found, that its domain is a workgoup (using wmic computersystem get domain in cmd) could that be an issue and how would I go and resolve this?

EDIT: Here the second.conf file:

spnego-client {
    com.sun.security.auth.module.Krb5LoginModule required;
};

spnego-server {
    com.sun.security.auth.module.Krb5LoginModule required
    storeKey=true
    isInitiator=false;
};

Answer 1

I checked the packages via wireshark and found the unkown pricipalname error. Thanks for the hint @Samson Scharfrichter

The correct spn registration is setspn.exe -A HTTP/ourserver01.example.com exampleUser without the project itself.