# -*- coding: utf-8 -*- """ pySim: various utilities only used by legacy tools (pySim-{prog,read}) """ # Copyright (C) 2009-2010 Sylvain Munaut # Copyright (C) 2021 Harald Welte # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see . # from pySim.utils import Hexstr, rpad, enc_plmn, h2i, i2s, s2h from pySim.utils import dec_xplmn_w_act, dec_xplmn, dec_mcc_from_plmn, dec_mnc_from_plmn def hexstr_to_Nbytearr(s, nbytes): return [s[i:i+(nbytes*2)] for i in range(0, len(s), (nbytes*2))] def format_xplmn_w_act(hexstr): s = "" for rec_data in hexstr_to_Nbytearr(hexstr, 5): rec_info = dec_xplmn_w_act(rec_data) if rec_info['mcc'] == "" and rec_info['mnc'] == "": rec_str = "unused" else: rec_str = "MCC: %s MNC: %s AcT: %s" % ( rec_info['mcc'], rec_info['mnc'], ", ".join(rec_info['act'])) s += "\t%s # %s\n" % (rec_data, rec_str) return s def format_xplmn(hexstr: Hexstr) -> str: s = "" for rec_data in hexstr_to_Nbytearr(hexstr, 3): rec_info = dec_xplmn(rec_data) if not rec_info['mcc'] and not rec_info['mnc']: rec_str = "unused" else: rec_str = "MCC: %s MNC: %s" % (rec_info['mcc'], rec_info['mnc']) s += "\t%s # %s\n" % (rec_data, rec_str) return s def format_ePDGSelection(hexstr): ePDGSelection_info_tag_chars = 2 ePDGSelection_info_tag_str = hexstr[:2] s = "" # Minimum length len_chars = 2 # TODO: Need to determine length properly - definite length support only # Inconsistency in spec: 3GPP TS 31.102 version 15.2.0 Release 15, 4.2.104 # As per spec, length is 5n, n - number of PLMNs # But, each PLMN entry is made of PLMN (3 Bytes) + ePDG Priority (2 Bytes) + ePDG FQDN format (1 Byte) # Totalling to 6 Bytes, maybe length should be 6n len_str = hexstr[ePDGSelection_info_tag_chars:ePDGSelection_info_tag_chars+len_chars] # Not programmed scenario if int(len_str, 16) == 255 or int(ePDGSelection_info_tag_str, 16) == 255: len_chars = 0 ePDGSelection_info_tag_chars = 0 if len_str[0] == '8': # The bits 7 to 1 denotes the number of length octets if length > 127 if int(len_str[1]) > 0: # Update number of length octets len_chars = len_chars * int(len_str[1]) len_str = hexstr[ePDGSelection_info_tag_chars:len_chars] content_str = hexstr[ePDGSelection_info_tag_chars+len_chars:] # Right pad to prevent index out of range - multiple of 6 bytes content_str = rpad(content_str, len(content_str) + (12 - (len(content_str) % 12))) for rec_data in hexstr_to_Nbytearr(content_str, 6): rec_info = dec_ePDGSelection(rec_data) if rec_info['mcc'] == 0xFFF and rec_info['mnc'] == 0xFFF: rec_str = "unused" else: rec_str = "MCC: %03d MNC: %03d ePDG Priority: %s ePDG FQDN format: %s" % \ (rec_info['mcc'], rec_info['mnc'], rec_info['epdg_priority'], rec_info['epdg_fqdn_format']) s += "\t%s # %s\n" % (rec_data, rec_str) return s def enc_st(st, service, state=1): """ Encodes the EF S/U/IST/EST and returns the updated Service Table Parameters: st - Current value of SIM/USIM/ISIM Service Table service - Service Number to encode as activated/de-activated state - 1 mean activate, 0 means de-activate Returns: s - Modified value of SIM/USIM/ISIM Service Table Default values: - state: 1 - Sets the particular Service bit to 1 """ st_bytes = [st[i:i+2] for i in range(0, len(st), 2)] s = "" # Check whether the requested service is present in each byte for i in range(0, len(st_bytes)): # Byte i contains info about Services num (8i+1) to num (8i+8) if service in range((8*i) + 1, (8*i) + 9): byte = int(st_bytes[i], 16) # Services in each byte are in order MSB to LSB # MSB - Service (8i+8) # LSB - Service (8i+1) mod_byte = 0x00 # Copy bit by bit contents of byte to mod_byte with modified bit # for requested service for j in range(1, 9): mod_byte = mod_byte >> 1 if service == (8*i) + j: mod_byte = state == 1 and mod_byte | 0x80 or mod_byte & 0x7f else: mod_byte = byte & 0x01 == 0x01 and mod_byte | 0x80 or mod_byte & 0x7f byte = byte >> 1 s += ('%02x' % (mod_byte)) else: s += st_bytes[i] return s def dec_st(st, table="sim") -> str: """ Parses the EF S/U/IST and prints the list of available services in EF S/U/IST """ if table == "isim": from pySim.ts_31_103 import EF_IST_map lookup_map = EF_IST_map elif table == "usim": from pySim.ts_31_102 import EF_UST_map lookup_map = EF_UST_map else: from pySim.ts_51_011 import EF_SST_map lookup_map = EF_SST_map st_bytes = [st[i:i+2] for i in range(0, len(st), 2)] avail_st = "" # Get each byte and check for available services for i in range(0, len(st_bytes)): # Byte i contains info about Services num (8i+1) to num (8i+8) byte = int(st_bytes[i], 16) # Services in each byte are in order MSB to LSB # MSB - Service (8i+8) # LSB - Service (8i+1) for j in range(1, 9): if byte & 0x01 == 0x01 and ((8*i) + j in lookup_map): # Byte X contains info about Services num (8X-7) to num (8X) # bit = 1: service available # bit = 0: service not available avail_st += '\tService %d - %s\n' % ( (8*i) + j, lookup_map[(8*i) + j]) byte = byte >> 1 return avail_st def enc_ePDGSelection(hexstr, mcc, mnc, epdg_priority='0001', epdg_fqdn_format='00'): """ Encode ePDGSelection so it can be stored at EF.ePDGSelection or EF.ePDGSelectionEm. See 3GPP TS 31.102 version 15.2.0 Release 15, section 4.2.104 and 4.2.106. Default values: - epdg_priority: '0001' - 1st Priority - epdg_fqdn_format: '00' - Operator Identifier FQDN """ plmn1 = enc_plmn(mcc, mnc) + epdg_priority + epdg_fqdn_format # TODO: Handle encoding of Length field for length more than 127 Bytes content = '80' + ('%02x' % (len(plmn1)//2)) + plmn1 content = rpad(content, len(hexstr)) return content def dec_ePDGSelection(sixhexbytes): """ Decode ePDGSelection to get EF.ePDGSelection or EF.ePDGSelectionEm. See 3GPP TS 31.102 version 15.2.0 Release 15, section 4.2.104 and 4.2.106. """ res = {'mcc': 0, 'mnc': 0, 'epdg_priority': 0, 'epdg_fqdn_format': ''} plmn_chars = 6 epdg_priority_chars = 4 epdg_fqdn_format_chars = 2 # first three bytes (six ascii hex chars) plmn_str = sixhexbytes[:plmn_chars] # two bytes after first three bytes epdg_priority_str = sixhexbytes[plmn_chars:plmn_chars + epdg_priority_chars] # one byte after first five bytes epdg_fqdn_format_str = sixhexbytes[plmn_chars + epdg_priority_chars:plmn_chars + epdg_priority_chars + epdg_fqdn_format_chars] res['mcc'] = dec_mcc_from_plmn(plmn_str) res['mnc'] = dec_mnc_from_plmn(plmn_str) res['epdg_priority'] = epdg_priority_str res['epdg_fqdn_format'] = epdg_fqdn_format_str == '00' and 'Operator Identifier FQDN' or 'Location based FQDN' return res def first_TLV_parser(bytelist): ''' first_TLV_parser([0xAA, 0x02, 0xAB, 0xCD, 0xFF, 0x00]) -> (170, 2, [171, 205]) parses first TLV format record in a list of bytelist returns a 3-Tuple: Tag, Length, Value Value is a list of bytes parsing of length is ETSI'style 101.220 ''' Tag = bytelist[0] if bytelist[1] == 0xFF: Len = bytelist[2]*256 + bytelist[3] Val = bytelist[4:4+Len] else: Len = bytelist[1] Val = bytelist[2:2+Len] return (Tag, Len, Val) def TLV_parser(bytelist): ''' TLV_parser([0xAA, ..., 0xFF]) -> [(T, L, [V]), (T, L, [V]), ...] loops on the input list of bytes with the "first_TLV_parser()" function returns a list of 3-Tuples ''' ret = [] while len(bytelist) > 0: T, L, V = first_TLV_parser(bytelist) if T == 0xFF: # padding bytes break ret.append((T, L, V)) # need to manage length of L if L > 0xFE: bytelist = bytelist[L+4:] else: bytelist = bytelist[L+2:] return ret def dec_addr_tlv(hexstr): """ Decode hex string to get EF.P-CSCF Address or EF.ePDGId or EF.ePDGIdEm. See 3GPP TS 31.102 version 13.4.0 Release 13, section 4.2.8, 4.2.102 and 4.2.104. """ # Convert from hex str to int bytes list addr_tlv_bytes = h2i(hexstr) # Get list of tuples containing parsed TLVs tlvs = TLV_parser(addr_tlv_bytes) for tlv in tlvs: # tlv = (T, L, [V]) # T = Tag # L = Length # [V] = List of value # Invalid Tag value scenario if tlv[0] != 0x80: continue # Empty field - Zero length if tlv[1] == 0: continue # Uninitialized field if all([v == 0xff for v in tlv[2]]): continue # First byte in the value has the address type addr_type = tlv[2][0] # TODO: Support parsing of IPv6 # Address Type: 0x00 (FQDN), 0x01 (IPv4), 0x02 (IPv6), other (Reserved) if addr_type == 0x00: # FQDN # Skip address tye byte i.e. first byte in value list content = tlv[2][1:] return (i2s(content), '00') elif addr_type == 0x01: # IPv4 # Skip address tye byte i.e. first byte in value list # Skip the unused byte in Octect 4 after address type byte as per 3GPP TS 31.102 ipv4 = tlv[2][2:] content = '.'.join(str(x) for x in ipv4) return (content, '01') else: raise ValueError("Invalid address type") return (None, None) def enc_addr_tlv(addr, addr_type='00'): """ Encode address TLV object used in EF.P-CSCF Address, EF.ePDGId and EF.ePDGIdEm. See 3GPP TS 31.102 version 13.4.0 Release 13, section 4.2.8, 4.2.102 and 4.2.104. Default values: - addr_type: 00 - FQDN format of Address """ s = "" # TODO: Encoding of IPv6 address if addr_type == '00': # FQDN hex_str = s2h(addr) s += '80' + ('%02x' % ((len(hex_str)//2)+1)) + '00' + hex_str elif addr_type == '01': # IPv4 ipv4_list = addr.split('.') ipv4_str = "" for i in ipv4_list: ipv4_str += ('%02x' % (int(i))) # Unused bytes shall be set to 'ff'. i.e 4th Octet after Address Type is not used # IPv4 Address is in octet 5 to octet 8 of the TLV data object s += '80' + ('%02x' % ((len(ipv4_str)//2)+2)) + '01' + 'ff' + ipv4_str return s