Add support for ADF_USIM/EF_EHPLMN

If the EF.EHPLMN exists, it contains the "Equivalent Home PLMN List".
The odd part of that list is that it is not just a list of additional
PLMN identities, but if the first digits of the IMSI are *not* listed
in EF.EHPLMN, then the MCC/MNC of the IMSI prefix is suddently no
longer considered the home network, but the subscriber is roaming.

See TS 23.122: "If the HPLMN code derived from the IMSI is not present
in the EHPLMN list, then it shall be treated as a Visited PLMN for PLMN
selection purposes."

Change-Id: I22d96ab4a424ec5bc1fb02f5e80165c646a748d3

5 files changed, 83 insertions, 4 deletions

diff --git a/pySim-read.py b/pySim-read.py
index 69cab4d..d6674a5 100755
--- a/pySim-read.py
+++ b/pySim-read.py
@@ -241,6 +241,13 @@ if __name__ == '__main__':
 	# Check whether we have th AID of USIM, if so select it by its AID
 	# EF.UST - File Id in ADF USIM : 6f38
 	if '9000' == card.select_adf_by_aid():
+		# EF.EHPLMN
+		if card.file_exists(EF_USIM_ADF_map['EHPLMN']):
+			(res, sw) = card.read_ehplmn()
+			if sw == '9000':
+				print("EHPLMN:\n%s" % (res))
+			else:
+				print("EHPLMN: Can't read, response code = %s" % (sw,))
 		# EF.UST
 		(res, sw) = card.read_binary(EF_USIM_ADF_map['UST'])
 		if sw == '9000':
diff --git a/pySim/cards.py b/pySim/cards.py
index 808fde1..2d779b3 100644
--- a/pySim/cards.py
+++ b/pySim/cards.py
@@ -24,6 +24,7 @@
 #
 
 from pySim.ts_51_011 import EF, DF
+from pySim.ts_31_102 import EF_USIM_ADF_map
 from pySim.utils import *
 from smartcard.util import toBytes
 
@@ -41,6 +42,13 @@ class Card(object):
 		print("warning: erasing is not supported for specified card type!")
 		return
 
+	def file_exists(self, fid):
+		res_arr = self._scc.try_select_file(fid)
+		for res in res_arr:
+		    if res[1] != '9000':
+			return False
+		return True
+
 	def verify_adm(self, key):
 		'''
 		Authenticate with ADM key
@@ -262,6 +270,25 @@ class Card(object):
 		len = self._scc.record_size(ef)
 		self._scc.update_record(ef, rec_no, "ff" * len, force_len=False, verify=True)
 
+class UsimCard(Card):
+	def __init__(self, ssc):
+		super(UsimCard, self).__init__(ssc)
+
+	def read_ehplmn(self):
+		(res, sw) = self._scc.read_binary(EF_USIM_ADF_map['EHPLMN'])
+		if sw == '9000':
+			return (format_xplmn(res), sw)
+		else:
+			return (None, sw)
+
+	def update_ehplmn(self, mcc, mnc):
+		data = self._scc.read_binary(EF_USIM_ADF_map['EHPLMN'], length=None, offset=0)
+		size = len(data[0]) // 2
+		ehplmn = enc_plmn(mcc, mnc)
+		data, sw = self._scc.update_binary(EF_USIM_ADF_map['EHPLMN'], ehplmn)
+		return sw
+
+
 
 class _MagicSimBase(Card):
 	"""
@@ -552,7 +579,7 @@ class SysmoSIMgr1(GrcardSim):
 			return None
 		return None
 
-class SysmoUSIMgr1(Card):
+class SysmoUSIMgr1(UsimCard):
 	"""
 	sysmocom sysmoUSIM-GR1
 	"""
@@ -653,7 +680,7 @@ class SysmoSIMgr2(Card):
 			data, sw = self._scc.update_record('6f42', 1, lpad(p['smsp'], 80))
 
 
-class SysmoUSIMSJS1(Card):
+class SysmoUSIMSJS1(UsimCard):
 	"""
 	sysmocom sysmoUSIM-SJS1
 	"""
@@ -1037,7 +1064,7 @@ class WavemobileSim(Card):
 		return None
 
 
-class SysmoISIMSJA2(Card):
+class SysmoISIMSJA2(UsimCard):
 	"""
 	sysmocom sysmoISIM-SJA2
 	"""
@@ -1144,16 +1171,22 @@ class SysmoISIMSJA2(Card):
 			if p.get('opc'):
 				self._scc.update_binary('af20', p['opc'], 17)
 
-		# update EF-USIM_AUTH_KEY in ADF.USIM
 		self._scc.select_file(['3f00'])
 		aid = self.read_aid()
 		if (aid):
+			# update EF-USIM_AUTH_KEY in ADF.USIM
 			self._scc.select_adf(aid)
 			if p.get('ki'):
 				self._scc.update_binary('af20', p['ki'], 1)
 			if p.get('opc'):
 				self._scc.update_binary('af20', p['opc'], 17)
 
+			# update EF.EHPLMN in ADF.USIM
+                        if self.file_exists(EF_USIM_ADF_map['EHPLMN']):
+				if p.get('mcc') and p.get('mnc'):
+					sw = self.update_ehplmn(p['mcc'], p['mnc'])
+					if sw != '9000':
+						print("Programming EHPLMN failed with code %s"%sw)
 		return
 
 
diff --git a/pySim/commands.py b/pySim/commands.py
index 7288b19..c260a97 100644
--- a/pySim/commands.py
+++ b/pySim/commands.py
@@ -100,6 +100,17 @@ class SimCardCommands(object):
 	def sel_ctrl(self, value):
 		self._sel_ctrl = value
 
+	def try_select_file(self, dir_list):
+		rv = []
+		if type(dir_list) is not list:
+			dir_list = [dir_list]
+		for i in dir_list:
+			data, sw = self._tp.send_apdu(self.cla_byte + "a4" + self.sel_ctrl + "02" + i)
+			rv.append((data, sw))
+			if sw != '9000':
+				return rv
+		return rv
+
 	def select_file(self, dir_list):
 		rv = []
 		if type(dir_list) is not list:
diff --git a/pySim/utils.py b/pySim/utils.py
index ac82774..dc14d58 100644
--- a/pySim/utils.py
+++ b/pySim/utils.py
@@ -125,6 +125,9 @@ def enc_spn(name, hplmn_disp=False, oplmn_disp=False):
 def hexstr_to_fivebytearr(s):
 	return [s[i:i+10] for i in range(0, len(s), 10) ]
 
+def hexstr_to_threebytearr(s):
+	return [s[i:i+6] for i in range(0, len(s), 6) ]
+
 # Accepts hex string representing three bytes
 def dec_mcc_from_plmn(plmn):
 	ia = h2i(plmn)
@@ -213,6 +216,25 @@ def dec_epsloci(hexstr):
 	res['status'] = h2i(hexstr[34:36])
 	return res
 
+def dec_xplmn(threehexbytes):
+	res = {'mcc': 0, 'mnc': 0, 'act': []}
+	plmn_chars = 6
+	plmn_str = threehexbytes[:plmn_chars]				# first three bytes (six ascii hex chars)
+	res['mcc'] = dec_mcc_from_plmn(plmn_str)
+	res['mnc'] = dec_mnc_from_plmn(plmn_str)
+	return res
+
+def format_xplmn(hexstr):
+	s = ""
+	for rec_data in hexstr_to_threebytearr(hexstr):
+		rec_info = dec_xplmn(rec_data)
+		if rec_info['mcc'] == 0xFFF and rec_info['mnc'] == 0xFFF:
+			rec_str = "unused"
+		else:
+			rec_str = "MCC: %03d MNC: %03d" % (rec_info['mcc'], rec_info['mnc'])
+		s += "\t%s # %s\n" % (rec_data, rec_str)
+	return s
+
 def derive_milenage_opc(ki_hex, op_hex):
 	"""
 	Run the milenage algorithm to calculate OPC from Ki and OP
diff --git a/pysim-testdata/sysmoISIM-SJA2.ok b/pysim-testdata/sysmoISIM-SJA2.ok
index fd3f252..6054840 100644
--- a/pysim-testdata/sysmoISIM-SJA2.ok
+++ b/pysim-testdata/sysmoISIM-SJA2.ok
@@ -100,6 +100,12 @@ SIM Service Table: ff33ffff3f003f0f300cf0c3f00000
 	Service 58 - Extension 8
 	Service 59 - MMS User Connectivity Parameters
 
+EHPLMN:
+        00f110 # MCC: 001 MNC: 001
+        ffffff # unused
+        ffffff # unused
+        ffffff # unused
+
 USIM Service Table: beff9f9de73e0408400170730000002e00000000
 	Service 2 - Fixed Dialling Numbers (FDN)
 	Service 3 - Extension 2