[Freeipa-users] cannot access to freeipa client's linux share from windows

[Alexander Bokovoy]

On to, 01 joulu 2016, Fujisan wrote:
>Hello,
>
>I have upgraded a client and a freeipa server from Fedora 24 to 25 recently.
>And I *cannot* access linux shares located on the F25 freeipa client from a
>windows desktop.
>But I can access linux shares located on the F25 freeipa server from that
>windows desktop.
>And I can access linux shares located on the F24 freeipa client from that
>windows desktop.
>
>To be clear, I have:
>  A/ 1 F25 freeipa server
>  B/ 1 F25 freeipa client
>  C/ 1 F24 freeipa client
>  D/ 1 windows desktop
>
>I can access linux shares of A from D.
>I can access linux shares of C from D.
>I *cannot* access linux shares of B from D.
>
>I get these messages on B in /var/log/samba/log.10.0.21.247 :
>
>[2016/12/01 11:42:19.218759,  1] ../source3/librpc/crypto/gse_
>krb5.c:534(fill_mem_keytab_from_dedicated_keytab)
>  ../source3/librpc/crypto/gse_krb5.c:534: smb_krb5_open_keytab failed (Key
>table name malformed)
>[2016/12/01 11:42:19.218800,  1] ../source3/librpc/crypto/gse_
>krb5.c:627(gse_krb5_get_server_keytab)
>  ../source3/librpc/crypto/gse_krb5.c:627: Error! Unable to set mem keytab
>- -1765328205
>[2016/12/01 11:42:19.218823,  1] ../auth/gensec/gensec_start.c:
>698(gensec_start_mech)
>  Failed to start GENSEC server mech gse_krb5: NT_STATUS_INTERNAL_ERROR
>[2016/12/01 11:42:19.261611,  1] ../source3/librpc/crypto/gse_
>krb5.c:534(fill_mem_keytab_from_dedicated_keytab)
>  ../source3/librpc/crypto/gse_krb5.c:534: smb_krb5_open_keytab failed (Key
>table name malformed)
>[2016/12/01 11:42:19.261638,  1] ../source3/librpc/crypto/gse_
>krb5.c:627(gse_krb5_get_server_keytab)
>  ../source3/librpc/crypto/gse_krb5.c:627: Error! Unable to set mem keytab
>- -1765328205
>[2016/12/01 11:42:19.261653,  1] ../auth/gensec/gensec_start.c:
>698(gensec_start_mech)
>  Failed to start GENSEC server mech gse_krb5: NT_STATUS_INTERNAL_ERROR
>[2016/12/01 11:42:19.263330,  2] ../source3/auth/auth.c:315(
>auth_check_ntlm_password)
>  check_ntlm_password:  Authentication for user [smith] -> [smith] FAILED
>with error NT_STATUS_NO_SUCH_USER
>[2016/12/01 11:42:19.263380,  2] ../auth/gensec/spnego.c:720(
>gensec_spnego_server_negTokenTarg)
>  SPNEGO login failed: NT_STATUS_NO_SUCH_USER
>[2016/12/01 11:42:19.270531,  1] ../source3/librpc/crypto/gse_
>krb5.c:534(fill_mem_keytab_from_dedicated_keytab)
>  ../source3/librpc/crypto/gse_krb5.c:534: smb_krb5_open_keytab failed (Key
>table name malformed)
>[2016/12/01 11:42:19.270562,  1] ../source3/librpc/crypto/gse_
>krb5.c:627(gse_krb5_get_server_keytab)
>  ../source3/librpc/crypto/gse_krb5.c:627: Error! Unable to set mem keytab
>- -1765328205
>[2016/12/01 11:42:19.270586,  1] ../auth/gensec/gensec_start.c:
>698(gensec_start_mech)
>  Failed to start GENSEC server mech gse_krb5: NT_STATUS_INTERNAL_ERROR
>[2016/12/01 11:42:19.313479,  1] ../source3/librpc/crypto/gse_
>krb5.c:534(fill_mem_keytab_from_dedicated_keytab)
>  ../source3/librpc/crypto/gse_krb5.c:534: smb_krb5_open_keytab failed (Key
>table name malformed)
>[2016/12/01 11:42:19.313506,  1] ../source3/librpc/crypto/gse_
>krb5.c:627(gse_krb5_get_server_keytab)
>  ../source3/librpc/crypto/gse_krb5.c:627: Error! Unable to set mem keytab
>- -1765328205
>[2016/12/01 11:42:19.313523,  1] ../auth/gensec/gensec_start.c:
>698(gensec_start_mech)
>  Failed to start GENSEC server mech gse_krb5: NT_STATUS_INTERNAL_ERROR
>[2016/12/01 11:42:19.315256,  2] ../source3/auth/auth.c:315(
>auth_check_ntlm_password)
>  check_ntlm_password:  Authentication for user [smith] -> [smith] FAILED
>with error NT_STATUS_NO_SUCH_USER
>[2016/12/01 11:42:19.315291,  2] ../auth/gensec/spnego.c:720(
>gensec_spnego_server_negTokenTarg)
>  SPNEGO login failed: NT_STATUS_NO_SUCH_USER
>
>Also from the F25 server, I have the following when I run smbclient
>
>f25server # smbclient -k -L f25desktop.mydomain
>lp_load_ex: changing to config backend registry
>session setup failed: NT_STATUS_LOGON_FAILURE
>
>But if i run it with a F24 desktop, it works:
>
>f25server # smbclient -k -L f24desktop.mydomain
>lp_load_ex: changing to config backend registry
>Domain=[MYDOMAIN] OS=[Windows 6.1] Server=[Samba 4.4.7]
>
>    Sharename       Type      Comment
>    ---------       ----      -------
>    IPC$            IPC       IPC Service (Samba Server Version 4.4.7)
>    data            Disk      /data on f24desktop
>    data2           Disk      /data2 on f24desktop
>    data3           Disk      /data3 on f24desktop
>    backup          Disk      /backup on f24desktop
>[...]
>
>
>net conf list on the f25desktop gives:
>
>f25desktop # net conf list
>[global]
>    workgroup = MYDOMAIN
>    realm = MYDOMAIN
>    netbios name = F25SERVER
>    server string = Samba Server Version %v
>    kerberos method = dedicated keytab
>    dedicated keytab file = FILE:/etc/samba/samba.keytab
There seem to be a change in Samba 4.5.0 which uses 'dedicated keytab
file' value as it is when constructing a memory keytab. As result,
libkrb5 is confused and does not know which keytab processing routine to
use (MEMORY:FILE:/etc/samba/samba.keytab is invalid).

You can replace the value by removing FILE: right now:

net conf setparm global 'dedicated keytab file' /etc/samba/samba.keytab

When no prefix is used, libkrb5 will default to FILE: itself.

We are going to look at changing the Samba code to strip the prefix from
the 'dedicated keytab file' when applying it to memory-based keytabs.

-- 
/ Alexander Bokovoy