sysmo_usimsjs1: check ADM1 length

The length of the ADM1 key is currently not checked. The key is 8
digits long for all sysmo-usim-sjs1 cards. Lets make sure that the
length is checked before trying to authenticate.

Change-Id: I10a89d8343c889f6c1b2cf3fc67d08dcf08790cf

sysmo_usimsjs1.py

@@ -236,6 +236,10 @@ def sysmo_usim_admin_auth(sim, adm1, force = False):
 		print "          (double check ADM1 and use option -f to override)"
 		return False
 
+        if(len(adm1) != 8):
+                print " * Error: Short ADM1, a valid ADM1 is 8 digits long!"
+                return False
+
 	# Try to authenticate
 	try:
 		print " * Authenticating..."