s3:libsmb: handle the smb signing states the same in the krb5 and ntlmssp cases

SMB signing works the same regardless of the used auth mech.

We need to start with the temp signing ("BSRSPYL ")
and the session setup response with NT_STATUS_OK
is the first signed packet.

Now we set the krb5 session key if we got the NT_STATUS_OK
from the server and then recheck the packet.

All this is needed to make the fallback from krb5 to
ntlmssp possible. This commit also resets the cli->vuid
value to 0, if the krb5 auth didn't succeed. Otherwise
the server handles NTLMSSP packets as krb5 packets.

The restructuring of the SMB signing code is needed to
make sure the krb5 code only starts the signing engine
on success. Otherwise the NTLMSSP fallback could not initialize
the signing engine (again).

metze
(cherry picked from commit 7d9fd64f38aa5821b38c1223cf87979fc87bfb71)
(cherry picked from commit 8e29070ccd0b5103af2e6da75644169f46700313)
(cherry picked from commit 38b297f99ec166e5c40ba33774222b37b45b4fec)
(a little bit modified to compile in v3-0)

diff --git a/source/libsmb/cliconnect.c b/source/libsmb/cliconnect.c
index b2425e32ec73d677aaa29a828bb7496900f0355f..519d392e8ab78e4b41c4f4092b78b3eee46e215a 100644 (file)
--- a/source/libsmb/cliconnect.c
+++ b/source/libsmb/cliconnect.c
@@ -538,7 +538,7 @@ static DATA_BLOB cli_session_setup_blob_receive(struct cli_state *cli)
 
 #define BASE_SESSSETUP_BLOB_PACKET_SIZE (35 + 24 + 22)
 
-static BOOL cli_session_setup_blob(struct cli_state *cli, DATA_BLOB blob, DATA_BLOB session_key_krb5)
+static BOOL cli_session_setup_blob(struct cli_state *cli, DATA_BLOB blob)
 {
        int32 remaining = blob.length;
        int32 cur = 0;
@@ -562,13 +562,8 @@ static BOOL cli_session_setup_blob(struct cli_state *cli, DATA_BLOB blob, DATA_B
                        send_blob.length = max_blob_size;
                        remaining -= max_blob_size;
                } else {
-                       DATA_BLOB null_blob = data_blob(NULL, 0);
-
                        send_blob.length = remaining; 
                         remaining = 0;
-
-                       /* This is the last packet in the sequence - turn signing on. */
-                       cli_simple_set_signing(cli, session_key_krb5, null_blob); 
                }
 
                send_blob.data =  &blob.data[cur];
@@ -616,8 +611,13 @@ static ADS_STATUS cli_session_setup_kerberos(struct cli_state *cli, const char *
 {
        DATA_BLOB negTokenTarg;
        DATA_BLOB session_key_krb5;
+       DATA_BLOB null_blob = data_blob(NULL, 0);
+       NTSTATUS nt_status;
+       BOOL res;
        int rc;
 
+       cli_temp_set_signing(cli);
+
        DEBUG(2,("Doing kerberos session setup\n"));
 
        /* generate the encapsulated kerberos5 ticket */
@@ -633,23 +633,43 @@ static ADS_STATUS cli_session_setup_kerberos(struct cli_state *cli, const char *
        file_save("negTokenTarg.dat", negTokenTarg.data, negTokenTarg.length);
 #endif
 
-       if (!cli_session_setup_blob(cli, negTokenTarg, session_key_krb5)) {
-               data_blob_free(&negTokenTarg);
-               data_blob_free(&session_key_krb5);
-               return ADS_ERROR_NT(cli_nt_error(cli));
+       if (!cli_session_setup_blob(cli, negTokenTarg)) {
+               nt_status = cli_nt_error(cli);
+               goto nt_error;
+       }
+
+       if (cli_is_error(cli)) {
+               nt_status = cli_nt_error(cli);
+               if (NT_STATUS_IS_OK(nt_status)) {
+                       nt_status = NT_STATUS_UNSUCCESSFUL;
+               }
+               goto nt_error;
        }
 
        cli_set_session_key(cli, session_key_krb5);
 
+       res = cli_simple_set_signing(cli, session_key_krb5, null_blob);
+       if (res) {
+               /* 'resign' the last message, so we get the right sequence numbers
+                  for checking the first reply from the server */
+               cli_calculate_sign_mac(cli);
+
+               if (!cli_check_sign_mac(cli)) {
+                       nt_status = NT_STATUS_ACCESS_DENIED;
+                       goto nt_error;
+               }
+       }
+
        data_blob_free(&negTokenTarg);
        data_blob_free(&session_key_krb5);
 
-       if (cli_is_error(cli)) {
-               if (NT_STATUS_IS_OK(cli_nt_error(cli))) {
-                       return ADS_ERROR_NT(NT_STATUS_UNSUCCESSFUL);
-               }
-       } 
-       return ADS_ERROR_NT(cli_nt_error(cli));
+       return ADS_ERROR_NT(NT_STATUS_OK);
+
+nt_error:
+       data_blob_free(&negTokenTarg);
+       data_blob_free(&session_key_krb5);
+       cli->vuid = 0;
+       return ADS_ERROR_NT(nt_status);
 }
 #endif /* HAVE_KRB5 */