From 4cab3bb1279d5f61bc6fff8eab4c9f0e1ebbc985 Mon Sep 17 00:00:00 2001
From: Philipp Maier <pmaier@sysmocom.de>
Date: Wed, 8 Aug 2018 10:49:26 +0200
Subject: [PATCH] sysmo-usim-tool.sjs1: Add capability to write IMSI

We unconditionally display the IMSI but we still lack support for
writing it. Lets support writing the IMSI as well in order to be more
complete.

- Add support for writing the IMSI

Change-Id: I1b3d1e1aae953663c13e78217de2a8ec3282b969
Related: OS#3376
---
 sysmo-usim-tool.sjs1.py | 13 +++++++++++--
 sysmo_usimsjs1.py       | 19 ++++++++++++++++++-
 utils.py                |  8 +++++---
 3 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/sysmo-usim-tool.sjs1.py b/sysmo-usim-tool.sjs1.py
index eb8e46c..16d44f5 100755
--- a/sysmo-usim-tool.sjs1.py
+++ b/sysmo-usim-tool.sjs1.py
@@ -54,6 +54,7 @@ def helptext():
 	print "   -s  --seq-parameters ........... Show MILENAGE SEQ/SQN parameters"
 	print "   -S  --reset-seq-parameters...... Reset MILENAGE SEQ/SQN parameters to default"
 	print "   -I, --set-iccid ................ Set ICCID value"
+	print "   -J, --set-imsi ................. Set IMSI value"
 	print ""
 
 
@@ -76,16 +77,18 @@ def main(argv):
 	getopt_write_iccid = None
 	getopt_seq_par = False
 	getopt_reset_seq_par = False
+	getopt_write_imsi = None
 
 	# Analyze commandline options
 	try:
 		opts, args = getopt.getopt(argv,
-			"ha:ucmtT:lL:oO:C:kK:fiI:sS",
+			"ha:ucmtT:lL:oO:C:kK:fiI:sSJ:",
 				["help","adm1=","usim","classic",
 				 "mode","auth","set-auth=","milenage",
 				 "set-milenage","opc","set-op=","set-opc=",
 				 "ki","set-ki=","force","iccid","set-iccid=",
-				 "seq-parameters", "reset-seq-parameters"])
+				 "seq-parameters", "reset-seq-parameters",
+                                 "set-imsi"])
 	except getopt.GetoptError:
 		print " * Error: Invalid commandline options"
 		sys.exit(2)
@@ -133,6 +136,8 @@ def main(argv):
 			getopt_seq_par = True
 		elif opt in ("-S", "--reset-sqe-parameters"):
 			getopt_reset_seq_par = True
+		elif opt in ("-J", "--set-imsi"):
+			getopt_write_imsi = asciihex_to_list(pad_asciihex(arg, True, '9'))
 
 
 	if not getopt_adm1:
@@ -234,6 +239,10 @@ def main(argv):
 		sysmo_usim_reset_milenage_sqn_params(sim)
 		print("")
 
+	if getopt_write_imsi:
+		print "Writing IMSI value..."
+		sysmo_usim_write_imsi(sim, getopt_write_imsi)
+		print("")
 
 	print "Done!"
 
diff --git a/sysmo_usimsjs1.py b/sysmo_usimsjs1.py
index d569b72..09dc249 100644
--- a/sysmo_usimsjs1.py
+++ b/sysmo_usimsjs1.py
@@ -47,7 +47,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #      +--[EF_OPC 0x00F7]
 #      |
 #      +--[EF_KI 0x00FF]
-
+#      |
+#      +--[EF_IMSI 0x6F07]
 
 import sys
 from card import *
@@ -574,3 +575,19 @@ def sysmo_usim_write_iccid(sim, iccid):
 
 	print " * Programming..."
 	sim.update_binary(swap_nibbles(iccid))
+
+
+# Program new IMSI value
+def sysmo_usim_write_imsi(sim, imsi):
+	print " * New ISMI setting:"
+	print "   IMSI: " + hexdump(imsi)
+
+	sysmo_usim_init(sim)
+
+        sim.select(GSM_SIM_DF_GSM)
+	sim.select(GSM_SIM_EF_IMSI)
+
+        imsi = [len(imsi)] + swap_nibbles(imsi)
+
+	print " * Programming..."
+	sim.update_binary(imsi)
diff --git a/utils.py b/utils.py
index b7777e0..f492778 100644
--- a/utils.py
+++ b/utils.py
@@ -51,10 +51,12 @@ def asciihex_to_list(string):
 
 
 # Pad an ascihex string with a nibble in case it is "incomplete"
-def pad_asciihex(string, padding='f'):
+def pad_asciihex(string, front=False, padding='f'):
 
-	if len(string) % 2 != 0:
-		return string + padding
+	if front and len(string) % 2 != 0:
+		return padding + string
+	elif len(string) % 2 != 0:
+                return string + padding
 	return string