We are trying use squid with kerberos and basic authentication, but we've been getting some trouble authenticating Windows Media Player. Our enviroment: Proxy server SO: Red Hat Enterprise Linux Server release 6.0 KDC SO: Windows Server 2008 R2 SQUID: 3.1.4 CLIENTS SO: Windows XP SP3 and Windows VISTA (both with WMP 11) We followed this guide: http://wiki.squid-cache.org/ConfigExamples/Authenticate/Kerberos and create, in the KDC, the user "squid" and your keytab file. Main files and configurations bellow: ########### 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 = MYDOMAIN dns_lookup_realm = true dns_lookup_kdc = true default_keytab_name = /etc/squid/squid-proxy.keytab ticket_lifetime = 24h forwardable = yes ; for Windows 2008 with AES default_tgs_enctypes = aes256-cts-hmac-sha1-96 rc4-hmac des-cbc-crc des-cbc-md5 default_tkt_enctypes = aes256-cts-hmac-sha1-96 rc4-hmac des-cbc-crc des-cbc-md5 permitted_enctypes = aes256-cts-hmac-sha1-96 rc4-hmac des-cbc-crc des-cbc-md5 [realms] DOMAIN = { kdc = KDC_NAME.MYDOMAIN admin_server = KDC_NAME.MYDOMAIN default_domain = MYDOMAIN } [domain_realm] .mydomain = MYDOMAIN mydomain = MYDOMAIN [appdefaults] pam = { debug = false ticket_lifetime = 36000 renew_lifetime = 36000 forwardable = true krb4_convert = false } ########## squid.conf #################### # KERBEROS Authentication auth_param negotiate program /usr/lib64/squid/squid_kerb_auth -d -s HTTP/myproxyname.mydomain@MYDOMAIN auth_param negotiate children 10 auth_param negotiate keep_alive on # Basic Authentication auth_param basic program /usr/lib64/squid/squid_ldap_auth -R -b "<my basedn>" -D "<my binddn>" -w <password> -f "sAMAccountName=%s" <KDC IP> auth_param basic children 10 auth_param basic realm Squid proxy-caching web server auth_param basic credentialsttl 2 hours auth_param basic casesensitive off # # Recommended minimum configuration: # acl manager proto cache_object acl localhost src 127.0.0.1/32 acl localhost src ::1/128 acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 acl to_localhost dst ::1/128 # Example rule allowing access from your local networks. # Adapt to list your (internal) IP networks from where browsing # should be allowed acl localnet src 10.0.0.0/8 # RFC1918 possible internal network acl localnet src 172.16.0.0/12 # RFC1918 possible internal network acl localnet src 192.168.0.0/16 # RFC1918 possible internal network acl localnet src fc00::/7 # RFC 4193 local private network range acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines acl SSL_ports port 443 acl Safe_ports port 80 # http acl Safe_ports port 21 # ftp acl Safe_ports port 443 # https acl Safe_ports port 70 # gopher acl Safe_ports port 210 # wais acl Safe_ports port 1025-65535 # unregistered ports acl Safe_ports port 280 # http-mgmt acl Safe_ports port 488 # gss-http acl Safe_ports port 591 # filemaker acl Safe_ports port 777 # multiling http acl CONNECT method CONNECT acl autentica_user-proxyauth proxy_auth REQUIRED http_access allow manager localhost http_access deny manager http_access deny !Safe_ports http_access deny CONNECT !SSL_ports http_access allow autentica_user-proxyauth http_access deny all hierarchy_stoplist cgi-bin ? cache_mem 50 MB maximum_object_size 51200 KB coredump_dir /var/spool/squid debug_options 28,9 29,9 cache_store_log none error_directory /usr/share/squid/errors/pt-br hierarchy_stoplist cgi-bin ? refresh_pattern ^ftp: 1440 20% 10080 refresh_pattern ^gopher: 1440 0% 1440 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0 refresh_pattern . 0 20% 4320 quick_abort_min -1 KB ############ SPN's in keytab file #################### KVNO Timestamp Principal ---- ----------------- -------------------------------------------------------- 3 12/31/69 21:00:00 HTTP/myproxyname.mydomain@MYDOMAIN (DES cbc mode with CRC-32) 3 12/31/69 21:00:00 HTTP/myproxyname.mydomain@MYDOMAIN (DES cbc mode with RSA-MD5) 3 12/31/69 21:00:00 HTTP/myproxyname.mydomain@MYDOMAIN (ArcFour with HMAC/md5) 3 12/31/69 21:00:00 HTTP/myproxyname.mydomain@MYDOMAIN (AES-256 CTS mode with 96-bit SHA-1 HMAC) 3 12/31/69 21:00:00 HTTP/myproxyname.mydomain@MYDOMAIN (AES-128 CTS mode with 96-bit SHA-1 HMAC) The problem: Sites with WMP embedded don't open the media requests (audio or video) and keep poping up requests for user and password. Tests and verifications already made: The first tcpdump showed us that when the client (wmp) did the TGS-REQ to the KDC the SPN was host/myproxyname.mydomain which KDC responded (TGS-REP) with the error "KRB_S_PRINCIPAL_UNKNOWN". Indeed, we didn't created a SPN host/myproxyname.mydomain in the squid account user, the only SPN we had was HTTP/myproxyname.mydomain. So, our first action was add in the squid account user and the keytab file, the SPN host/myproxyname.mydomain but it didn't work. So, our second action was to create, in the KDC, a machine account called "myproxyname" and put there the SPN host/myproxyname.mydomain. The error "KRB_S_PRINCIPAL_UNKNOWN" didn't occur anymore, as confirmed by tcpdump, but still WMP continued requesting for user and password. At this point we saw that when WMP couldn't authenticate via kerberos, it fellback into NTLM, but we couldn't find kerbero errors in the tcpdump. So, the question is: Why fallback to NTLM if only exists Negotiate/Kerberos and Basic authentications? The Real Media Player works fine, it falls back to Basic authentication. Has anyone else faced this problem? The strangest thing was that even when we enable NTLM authentication below the Negotiate lines, the WMP requests continued to be treated by program squid_kerb_auth, thus, they never authenticated via NTLM program. Please, any help or idea how solve this problem? Thanks in advance. Some links already visited: http://blogs.technet.com/b/askds/archive/2008/06/09/kerberos-authentication-problems-service-principal-name-spn-issues-part-2.aspx http://technet.microsoft.com/en-us/library/cc749438(WS.10).aspx
