FC5 - problems setting context

[Sandra Rueda]

Hello,

I am new with selinux and I have a problem:

My system: Fedora Core 5, FC5 - 2.6.16-1.2122 SMP
I am trying to set communication policies between two machines and I am
using the set of commands implemented by ipsec-tools.

I am running the command: setkey -v -f set.conf
Contents of the file set.conf (it had more things at the beginning but I
reduced it while looking for the cause of the error):
flush;
spdflush;
spdadd src dest any -ctx 1 1 "user_u:object_r:user_t" -P out ipsec
esp/transport//require ;

I always receive the same output at the end: "Invalid Argument".

sadb_msg{ version=2 type=9 errno=0 satype=0
  len=2 reserved=0 seq=0 pid=16090

sadb_msg{ version=2 type=9 errno=0 satype=0
  len=2 reserved=0 seq=0 pid=16090

sadb_msg{ version=2 type=19 errno=0 satype=0
  len=2 reserved=0 seq=0 pid=16090

sadb_msg{ version=2 type=19 errno=0 satype=0
  len=2 reserved=0 seq=0 pid=16090

sadb_msg{ version=2 type=14 errno=0 satype=0
  len=16 reserved=0 seq=0 pid=16090
sadb_ext{ len=4 type=18 }
sadb_x_policy{ type=2 dir=2 id=0 priority=2147483648 }
 { len=16 proto=50 mode=1 level=2 reqid=0
 }
sadb_ext{ len=3 type=5 }
sadb_address{ proto=255 prefixlen=32 reserved=0x0000 }
sockaddr{ len=16 family=2 port=0
 82cb2034  }
sadb_ext{ len=3 type=6 }
sadb_address{ proto=255 prefixlen=32 reserved=0x0000 }
sockaddr{ len=16 family=2 port=0
 82cb2035  }
sadb_ext{ len=4 type=24 }
sadb_x_sec_ctx{ doi=1 alg=1 length=23,
context:user_u:object_r:user_t}

sadb_msg{ version=2 type=14 errno=22 satype=0
  len=2 reserved=0 seq=0 pid=16090

The result of line 4: Invalid argument.

I followed the procedure and it looks like the problem is not related to
ipsec-tools but to something in the kernel, because it returns errno=22.
Running the same command without the ctx extension works fine.

Does anyone have any idea?

Thanks,
Sandra