Files
appointment_tool/gsmmodem/pdu.py
T

954 lines
35 KiB
Python

# -*- coding: utf8 -*-
""" SMS PDU encoding methods """
from __future__ import unicode_literals
import sys, codecs
from datetime import datetime, timedelta, tzinfo
from copy import copy
from .exceptions import EncodingError
# For Python 3 support
PYTHON_VERSION = sys.version_info[0]
if PYTHON_VERSION >= 3:
MAX_INT = sys.maxsize
dictItemsIter = dict.items
xrange = range
unichr = chr
toByteArray = lambda x: bytearray(codecs.decode(x, 'hex_codec')) if type(x) == bytes else bytearray(codecs.decode(bytes(x, 'ascii'), 'hex_codec')) if type(x) == str else x
rawStrToByteArray = lambda x: bytearray(bytes(x, 'latin-1'))
TEXT_MODE = ('\n\r !\"#%&\'()*+,-./0123456789:;<=>?ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz') # TODO: Check if all of them are supported inside text mode
# Tables can be found at: http://en.wikipedia.org/wiki/GSM_03.38#GSM_7_bit_default_alphabet_and_extension_table_of_3GPP_TS_23.038_.2F_GSM_03.38
GSM7_BASIC = ('@£$¥èéùìòÇ\nØø\rÅåΔ_ΦΓΛΩΠΨΣΘΞ\x1bÆæßÉ !\"%&\'()*+,-./0123456789:;<=>?¡ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÑÜ`¿abcdefghijklmnopqrstuvwxyzäöñüà')
GSM7_EXTENDED = {chr(0xFF): 0x0A,
#CR2: chr(0x0D),
'^': chr(0x14),
#SS2: chr(0x1B),
'{': chr(0x28),
'}': chr(0x29),
'\\': chr(0x2F),
'[': chr(0x3C),
'~': chr(0x3D),
']': chr(0x3E),
'|': chr(0x40),
'': chr(0x65)}
# Maximum message sizes for each data coding
MAX_MESSAGE_LENGTH = {0x00: 160, # GSM-7
0x04: 140, # 8-bit
0x08: 70} # UCS2
# Maximum message sizes for each data coding for multipart messages
MAX_MULTIPART_MESSAGE_LENGTH = {0x00: 153, # GSM-7
0x04: 133, # 8-bit TODO: Check this value!
0x08: 67} # UCS2
class SmsPduTzInfo(tzinfo):
""" Simple implementation of datetime.tzinfo for handling timestamp GMT offsets specified in SMS PDUs """
def __init__(self, pduOffsetStr=None):
"""
:param pduOffset: 2 semi-octet timezone offset as specified by PDU (see GSM 03.40 spec)
:type pduOffset: str
Note: pduOffsetStr is optional in this constructor due to the special requirement for pickling
mentioned in the Python docs. It should, however, be used (or otherwise pduOffsetStr must be
manually set)
"""
self._offset = None
if pduOffsetStr != None:
self._setPduOffsetStr(pduOffsetStr)
def _setPduOffsetStr(self, pduOffsetStr):
# See if the timezone difference is positive/negative by checking MSB of first semi-octet
tzHexVal = int(pduOffsetStr, 16)
# In order to read time zone 'minute' shift:
# - Remove MSB (sign)
# - Read HEX value as decimal
# - Multiply by 15
# See: https://en.wikipedia.org/wiki/GSM_03.40#Time_Format
# Possible fix for #15 - convert invalid character to BCD-value
if (tzHexVal & 0x0F) > 0x9:
tzHexVal +=0x06
tzOffsetMinutes = int('{0:0>2X}'.format(tzHexVal & 0x7F)) * 15
if tzHexVal & 0x80 == 0: # positive
self._offset = timedelta(minutes=(tzOffsetMinutes))
else: # negative
self._offset = timedelta(minutes=(-tzOffsetMinutes))
def utcoffset(self, dt):
return self._offset
def dst(self, dt):
""" We do not have enough info in the SMS PDU to implement daylight savings time """
return timedelta(0)
class InformationElement(object):
""" User Data Header (UDH) Information Element (IE) implementation
This represents a single field ("information element") in the PDU's
User Data Header. The UDH itself contains one or more of these
information elements.
If the IEI (IE identifier) is recognized, the class will automatically
specialize into one of the subclasses of InformationElement,
e.g. Concatenation or PortAddress, allowing the user to easily
access the specific (and useful) attributes of these special cases.
"""
def __new__(cls, *args, **kwargs): #iei, ieLen, ieData):
""" Causes a new InformationElement class, or subclass
thereof, to be created. If the IEI is recognized, a specific
subclass of InformationElement is returned """
if len(args) > 0:
targetClass = IEI_CLASS_MAP.get(args[0], cls)
elif 'iei' in kwargs:
targetClass = IEI_CLASS_MAP.get(kwargs['iei'], cls)
else:
return super(InformationElement, cls).__new__(cls)
return super(InformationElement, targetClass).__new__(targetClass)
def __init__(self, iei, ieLen=0, ieData=None):
self.id = iei # IEI
self.dataLength = ieLen # IE Length
self.data = ieData or [] # raw IE data
@classmethod
def decode(cls, byteIter):
""" Decodes a single IE at the current position in the specified
byte iterator
:return: An InformationElement (or subclass) instance for the decoded IE
:rtype: InformationElement, or subclass thereof
"""
iei = next(byteIter)
ieLen = next(byteIter)
ieData = []
for i in xrange(ieLen):
ieData.append(next(byteIter))
return InformationElement(iei, ieLen, ieData)
def encode(self):
""" Encodes this IE and returns the resulting bytes """
result = bytearray()
result.append(self.id)
result.append(self.dataLength)
result.extend(self.data)
return result
def __len__(self):
""" Exposes the IE's total length (including the IEI and IE length octet) in octets """
return self.dataLength + 2
class Concatenation(InformationElement):
""" IE that indicates SMS concatenation.
This implementation handles both 8-bit and 16-bit concatenation
indication, and exposes the specific useful details of this
IE as instance variables.
Exposes:
reference
CSMS reference number, must be same for all the SMS parts in the CSMS
parts
total number of parts. The value shall remain constant for every short
message which makes up the concatenated short message. If the value is zero then
the receiving entity shall ignore the whole information element
number
this part's number in the sequence. The value shall start at 1 and
increment for every short message which makes up the concatenated short message
"""
def __init__(self, iei=0x00, ieLen=0, ieData=None):
super(Concatenation, self).__init__(iei, ieLen, ieData)
if ieData != None:
if iei == 0x00: # 8-bit reference
self.reference, self.parts, self.number = ieData
else: # 0x08: 16-bit reference
self.reference = ieData[0] << 8 | ieData[1]
self.parts = ieData[2]
self.number = ieData[3]
def encode(self):
if self.reference > 0xFF:
self.id = 0x08 # 16-bit reference
self.data = [self.reference >> 8, self.reference & 0xFF, self.parts, self.number]
else:
self.id = 0x00 # 8-bit reference
self.data = [self.reference, self.parts, self.number]
self.dataLength = len(self.data)
return super(Concatenation, self).encode()
class PortAddress(InformationElement):
""" IE that indicates an Application Port Addressing Scheme.
This implementation handles both 8-bit and 16-bit concatenation
indication, and exposes the specific useful details of this
IE as instance variables.
Exposes:
destination: The destination port number
source: The source port number
"""
def __init__(self, iei=0x04, ieLen=0, ieData=None):
super(PortAddress, self).__init__(iei, ieLen, ieData)
if ieData != None:
if iei == 0x04: # 8-bit port addressing scheme
self.destination, self.source = ieData
else: # 0x05: 16-bit port addressing scheme
self.destination = ieData[0] << 8 | ieData[1]
self.source = ieData[2] << 8 | ieData[3]
def encode(self):
if self.destination > 0xFF or self.source > 0xFF:
self.id = 0x05 # 16-bit
self.data = [self.destination >> 8, self.destination & 0xFF, self.source >> 8, self.source & 0xFF]
else:
self.id = 0x04 # 8-bit
self.data = [self.destination, self.source]
self.dataLength = len(self.data)
return super(PortAddress, self).encode()
# Map of recognized IEIs
IEI_CLASS_MAP = {0x00: Concatenation, # Concatenated short messages, 8-bit reference number
0x08: Concatenation, # Concatenated short messages, 16-bit reference number
0x04: PortAddress, # Application port addressing scheme, 8 bit address
0x05: PortAddress # Application port addressing scheme, 16 bit address
}
class Pdu(object):
""" Encoded SMS PDU. Contains raw PDU data and related meta-information """
def __init__(self, data, tpduLength):
""" Constructor
:param data: the raw PDU data (as bytes)
:type data: bytearray
:param tpduLength: Length (in bytes) of the TPDU
:type tpduLength: int
"""
self.data = data
self.tpduLength = tpduLength
def __str__(self):
global PYTHON_VERSION
if PYTHON_VERSION < 3:
return str(self.data).encode('hex').upper()
else: #pragma: no cover
return str(codecs.encode(self.data, 'hex_codec'), 'ascii').upper()
def encodeSmsSubmitPdu(number, text, reference=0, validity=None, smsc=None, requestStatusReport=True, rejectDuplicates=False, sendFlash=False):
""" Creates an SMS-SUBMIT PDU for sending a message with the specified text to the specified number
:param number: the destination mobile number
:type number: str
:param text: the message text
:type text: str
:param reference: message reference number (see also: rejectDuplicates parameter)
:type reference: int
:param validity: message validity period (absolute or relative)
:type validity: datetime.timedelta (relative) or datetime.datetime (absolute)
:param smsc: SMSC number to use (leave None to use default)
:type smsc: str
:param rejectDuplicates: Flag that controls the TP-RD parameter (messages with same destination and reference may be rejected if True)
:type rejectDuplicates: bool
:return: A list of one or more tuples containing the SMS PDU (as a bytearray, and the length of the TPDU part
:rtype: list of tuples
"""
if PYTHON_VERSION < 3:
if type(text) == str:
text = text.decode('UTF-8')
tpduFirstOctet = 0x01 # SMS-SUBMIT PDU
if validity != None:
# Validity period format (TP-VPF) is stored in bits 4,3 of the first TPDU octet
if type(validity) == timedelta:
# Relative (TP-VP is integer)
tpduFirstOctet |= 0x10 # bit4 == 1, bit3 == 0
validityPeriod = [_encodeRelativeValidityPeriod(validity)]
elif type(validity) == datetime:
# Absolute (TP-VP is semi-octet encoded date)
tpduFirstOctet |= 0x18 # bit4 == 1, bit3 == 1
validityPeriod = _encodeTimestamp(validity)
else:
raise TypeError('"validity" must be of type datetime.timedelta (for relative value) or datetime.datetime (for absolute value)')
else:
validityPeriod = None
if rejectDuplicates:
tpduFirstOctet |= 0x04 # bit2 == 1
if requestStatusReport:
tpduFirstOctet |= 0x20 # bit5 == 1
# Encode message text and set data coding scheme based on text contents
try:
encodedTextLength = len(encodeGsm7(text))
except ValueError:
# Cannot encode text using GSM-7; use UCS2 instead
encodedTextLength = len(text)
alphabet = 0x08 # UCS2
else:
alphabet = 0x00 # GSM-7
# Check if message should be concatenated
if encodedTextLength > MAX_MESSAGE_LENGTH[alphabet]:
# Text too long for single PDU - add "concatenation" User Data Header
concatHeaderPrototype = Concatenation()
concatHeaderPrototype.reference = reference
# Devide whole text into parts
if alphabet == 0x00:
pduTextParts = divideTextGsm7(text)
elif alphabet == 0x08:
pduTextParts = divideTextUcs2(text)
else:
raise NotImplementedError
pduCount = len(pduTextParts)
concatHeaderPrototype.parts = pduCount
tpduFirstOctet |= 0x40
else:
concatHeaderPrototype = None
pduCount = 1
# Construct required PDU(s)
pdus = []
for i in xrange(pduCount):
pdu = bytearray()
if smsc:
pdu.extend(_encodeAddressField(smsc, smscField=True))
else:
pdu.append(0x00) # Don't supply an SMSC number - use the one configured in the device
udh = bytearray()
if concatHeaderPrototype != None:
concatHeader = copy(concatHeaderPrototype)
concatHeader.number = i + 1
pduText = pduTextParts[i]
pduTextLength = len(pduText)
udh.extend(concatHeader.encode())
else:
pduText = text
udhLen = len(udh)
pdu.append(tpduFirstOctet)
pdu.append(reference) # message reference
# Add destination number
pdu.extend(_encodeAddressField(number))
pdu.append(0x00) # Protocol identifier - no higher-level protocol
pdu.append(alphabet if not sendFlash else (0x10 if alphabet == 0x00 else 0x18))
if validityPeriod:
pdu.extend(validityPeriod)
if alphabet == 0x00: # GSM-7
encodedText = encodeGsm7(pduText)
userDataLength = len(encodedText) # Payload size in septets/characters
if udhLen > 0:
shift = ((udhLen + 1) * 8) % 7 # "fill bits" needed to make the UDH end on a septet boundary
userData = packSeptets(encodedText, padBits=shift)
if shift > 0:
userDataLength += 1 # take padding bits into account
else:
userData = packSeptets(encodedText)
elif alphabet == 0x08: # UCS2
userData = encodeUcs2(pduText)
userDataLength = len(userData)
if udhLen > 0:
userDataLength += udhLen + 1 # +1 for the UDH length indicator byte
pdu.append(userDataLength)
pdu.append(udhLen)
pdu.extend(udh) # UDH
else:
pdu.append(userDataLength)
pdu.extend(userData) # User Data (message payload)
tpdu_length = len(pdu) - 1
pdus.append(Pdu(pdu, tpdu_length))
return pdus
def decodeSmsPdu(pdu):
""" Decodes SMS pdu data and returns a tuple in format (number, text)
:param pdu: PDU data as a hex string, or a bytearray containing PDU octects
:type pdu: str or bytearray
:raise EncodingError: If the specified PDU data cannot be decoded
:return: The decoded SMS data as a dictionary
:rtype: dict
"""
try:
pdu = toByteArray(pdu)
except Exception as e:
# Python 2 raises TypeError, Python 3 raises binascii.Error
raise EncodingError(e)
result = {}
pduIter = iter(pdu)
smscNumber, smscBytesRead = _decodeAddressField(pduIter, smscField=True)
result['smsc'] = smscNumber
result['tpdu_length'] = len(pdu) - smscBytesRead
tpduFirstOctet = next(pduIter)
pduType = tpduFirstOctet & 0x03 # bits 1-0
if pduType == 0x00: # SMS-DELIVER or SMS-DELIVER REPORT
result['type'] = 'SMS-DELIVER'
result['number'] = _decodeAddressField(pduIter)[0]
result['protocol_id'] = next(pduIter)
dataCoding = _decodeDataCoding(next(pduIter))
result['time'] = _decodeTimestamp(pduIter)
userDataLen = next(pduIter)
udhPresent = (tpduFirstOctet & 0x40) != 0
ud = _decodeUserData(pduIter, userDataLen, dataCoding, udhPresent)
result.update(ud)
elif pduType == 0x01: # SMS-SUBMIT or SMS-SUBMIT-REPORT
result['type'] = 'SMS-SUBMIT'
result['reference'] = next(pduIter) # message reference - we don't really use this
result['number'] = _decodeAddressField(pduIter)[0]
result['protocol_id'] = next(pduIter)
dataCoding = _decodeDataCoding(next(pduIter))
validityPeriodFormat = (tpduFirstOctet & 0x18) >> 3 # bits 4,3
if validityPeriodFormat == 0x02: # TP-VP field present and integer represented (relative)
result['validity'] = _decodeRelativeValidityPeriod(next(pduIter))
elif validityPeriodFormat == 0x03: # TP-VP field present and semi-octet represented (absolute)
result['validity'] = _decodeTimestamp(pduIter)
userDataLen = next(pduIter)
udhPresent = (tpduFirstOctet & 0x40) != 0
ud = _decodeUserData(pduIter, userDataLen, dataCoding, udhPresent)
result.update(ud)
elif pduType == 0x02: # SMS-STATUS-REPORT or SMS-COMMAND
result['type'] = 'SMS-STATUS-REPORT'
result['reference'] = next(pduIter)
result['number'] = _decodeAddressField(pduIter)[0]
result['time'] = _decodeTimestamp(pduIter)
result['discharge'] = _decodeTimestamp(pduIter)
result['status'] = next(pduIter)
else:
raise EncodingError('Unknown SMS message type: {0}. First TPDU octet was: {1}'.format(pduType, tpduFirstOctet))
return result
def _decodeUserData(byteIter, userDataLen, dataCoding, udhPresent):
""" Decodes PDU user data (UDHI (if present) and message text) """
result = {}
if udhPresent:
# User Data Header is present
result['udh'] = []
udhLen = next(byteIter)
ieLenRead = 0
# Parse and store UDH fields
while ieLenRead < udhLen:
ie = InformationElement.decode(byteIter)
ieLenRead += len(ie)
result['udh'].append(ie)
del ieLenRead
if dataCoding == 0x00: # GSM-7
# Since we are using 7-bit data, "fill bits" may have been added to make the UDH end on a septet boundary
shift = ((udhLen + 1) * 8) % 7 # "fill bits" needed to make the UDH end on a septet boundary
# Simulate another "shift" in the unpackSeptets algorithm in order to ignore the fill bits
prevOctet = next(byteIter)
shift += 1
if dataCoding == 0x00: # GSM-7
if udhPresent:
userDataSeptets = unpackSeptets(byteIter, userDataLen, prevOctet, shift)
else:
userDataSeptets = unpackSeptets(byteIter, userDataLen)
result['text'] = decodeGsm7(userDataSeptets)
elif dataCoding == 0x02: # UCS2
result['text'] = decodeUcs2(byteIter, userDataLen)
else: # 8-bit (data)
userData = []
for b in byteIter:
userData.append(unichr(b))
result['text'] = ''.join(userData)
return result
def _decodeRelativeValidityPeriod(tpVp):
""" Calculates the relative SMS validity period (based on the table in section 9.2.3.12 of GSM 03.40)
:rtype: datetime.timedelta
"""
if tpVp <= 143:
return timedelta(minutes=((tpVp + 1) * 5))
elif 144 <= tpVp <= 167:
return timedelta(hours=12, minutes=((tpVp - 143) * 30))
elif 168 <= tpVp <= 196:
return timedelta(days=(tpVp - 166))
elif 197 <= tpVp <= 255:
return timedelta(weeks=(tpVp - 192))
else:
raise ValueError('tpVp must be in range [0, 255]')
def _encodeRelativeValidityPeriod(validityPeriod):
""" Encodes the specified relative validity period timedelta into an integer for use in an SMS PDU
(based on the table in section 9.2.3.12 of GSM 03.40)
:param validityPeriod: The validity period to encode
:type validityPeriod: datetime.timedelta
:rtype: int
"""
# Python 2.6 does not have timedelta.total_seconds(), so compute it manually
#seconds = validityPeriod.total_seconds()
seconds = validityPeriod.seconds + (validityPeriod.days * 24 * 3600)
if seconds <= 43200: # 12 hours
tpVp = int(seconds / 300) - 1 # divide by 5 minutes, subtract 1
elif seconds <= 86400: # 24 hours
tpVp = int((seconds - 43200) / 1800) + 143 # subtract 12 hours, divide by 30 minutes. add 143
elif validityPeriod.days <= 30: # 30 days
tpVp = validityPeriod.days + 166 # amount of days + 166
elif validityPeriod.days <= 441: # max value of tpVp is 255
tpVp = int(validityPeriod.days / 7) + 192 # amount of weeks + 192
else:
raise ValueError('Validity period too long; tpVp limited to 1 octet (max value: 255)')
return tpVp
def _decodeTimestamp(byteIter):
""" Decodes a 7-octet timestamp """
dateStr = decodeSemiOctets(byteIter, 7)
timeZoneStr = dateStr[-2:]
return datetime.strptime(dateStr[:-2], '%y%m%d%H%M%S').replace(tzinfo=SmsPduTzInfo(timeZoneStr))
def _encodeTimestamp(timestamp):
""" Encodes a 7-octet timestamp from the specified date
Note: the specified timestamp must have a UTC offset set; you can use gsmmodem.util.SimpleOffsetTzInfo for simple cases
:param timestamp: The timestamp to encode
:type timestamp: datetime.datetime
:return: The encoded timestamp
:rtype: bytearray
"""
if timestamp.tzinfo == None:
raise ValueError('Please specify time zone information for the timestamp (e.g. by using gsmmodem.util.SimpleOffsetTzInfo)')
# See if the timezone difference is positive/negative
tzDelta = timestamp.utcoffset()
if tzDelta.days >= 0:
tzValStr = '{0:0>2}'.format(int(tzDelta.seconds / 60 / 15))
else: # negative
tzVal = int((tzDelta.days * -3600 * 24 - tzDelta.seconds) / 60 / 15) # calculate offset in 0.25 hours
# Cast as literal hex value and set MSB of first semi-octet of timezone to 1 to indicate negative value
tzVal = int('{0:0>2}'.format(tzVal), 16) | 0x80
tzValStr = '{0:0>2X}'.format(tzVal)
dateStr = timestamp.strftime('%y%m%d%H%M%S') + tzValStr
return encodeSemiOctets(dateStr)
def _decodeDataCoding(octet):
if octet & 0xC0 == 0:
#compressed = octect & 0x20
alphabet = (octet & 0x0C) >> 2
return alphabet # 0x00 == GSM-7, 0x01 == 8-bit data, 0x02 == UCS2
# We ignore other coding groups
return 0
def nibble2octet(addressLen):
return int((addressLen + 1) / 2)
def _decodeAddressField(byteIter, smscField=False, log=False):
""" Decodes the address field at the current position of the bytearray iterator
:param byteIter: Iterator over bytearray
:type byteIter: iter(bytearray)
:return: Tuple containing the address value and amount of bytes read (value is or None if it is empty (zero-length))
:rtype: tuple
"""
addressLen = next(byteIter)
if addressLen > 0:
toa = next(byteIter)
ton = (toa & 0x70) # bits 6,5,4 of type-of-address == type-of-number
if ton == 0x50:
# Alphanumberic number
addressLen = nibble2octet(addressLen)
septets = unpackSeptets(byteIter, addressLen)
addressValue = decodeGsm7(septets)
return (addressValue, (addressLen + 2))
else:
# ton == 0x00: Unknown (might be international, local, etc) - leave as is
# ton == 0x20: National number
if smscField:
addressValue = decodeSemiOctets(byteIter, addressLen-1)
else:
addressLen = nibble2octet(addressLen)
addressValue = decodeSemiOctets(byteIter, addressLen)
addressLen += 1 # for the return value, add the toa byte
if ton == 0x10: # International number
addressValue = '+' + addressValue
return (addressValue, (addressLen + 1))
else:
return (None, 1)
def _encodeAddressField(address, smscField=False):
""" Encodes the address into an address field
:param address: The address to encode (phone number or alphanumeric)
:type byteIter: str
:return: Encoded SMS PDU address field
:rtype: bytearray
"""
# First, see if this is a number or an alphanumeric string
toa = 0x80 | 0x00 | 0x01 # Type-of-address start | Unknown type-of-number | ISDN/tel numbering plan
alphaNumeric = False
if address.isalnum():
# Might just be a local number
if address.isdigit():
# Local number
toa |= 0x20
else:
# Alphanumeric address
toa |= 0x50
toa &= 0xFE # switch to "unknown" numbering plan
alphaNumeric = True
else:
if address[0] == '+' and address[1:].isdigit():
# International number
toa |= 0x10
# Remove the '+' prefix
address = address[1:]
else:
# Alphanumeric address
toa |= 0x50
toa &= 0xFE # switch to "unknown" numbering plan
alphaNumeric = True
if alphaNumeric:
addressValue = packSeptets(encodeGsm7(address, False))
addressLen = len(addressValue) * 2
else:
addressValue = encodeSemiOctets(address)
if smscField:
addressLen = len(addressValue) + 1
else:
addressLen = len(address)
result = bytearray()
result.append(addressLen)
result.append(toa)
result.extend(addressValue)
return result
def encodeSemiOctets(number):
""" Semi-octet encoding algorithm (e.g. for phone numbers)
:return: bytearray containing the encoded octets
:rtype: bytearray
"""
if len(number) % 2 == 1:
number = number + 'F' # append the "end" indicator
octets = [int(number[i+1] + number[i], 16) for i in xrange(0, len(number), 2)]
return bytearray(octets)
def decodeSemiOctets(encodedNumber, numberOfOctets=None):
""" Semi-octet decoding algorithm(e.g. for phone numbers)
:param encodedNumber: The semi-octet-encoded telephone number (in bytearray format or hex string)
:type encodedNumber: bytearray, str or iter(bytearray)
:param numberOfOctets: The expected amount of octets after decoding (i.e. when to stop)
:type numberOfOctets: int
:return: decoded telephone number
:rtype: string
"""
number = []
if type(encodedNumber) in (str, bytes):
encodedNumber = bytearray(codecs.decode(encodedNumber, 'hex_codec'))
i = 0
for octet in encodedNumber:
hexVal = hex(octet)[2:].zfill(2)
number.append(hexVal[1])
if hexVal[0] != 'f':
number.append(hexVal[0])
else:
break
if numberOfOctets != None:
i += 1
if i == numberOfOctets:
break
return ''.join(number)
def encodeTextMode(plaintext):
""" Text mode checker
Tests whther SMS could be sent in text mode
:param text: the text string to encode
:raise ValueError: if the text string cannot be sent in text mode
:return: Passed string
:rtype: str
"""
if PYTHON_VERSION >= 3:
plaintext = str(plaintext)
elif type(plaintext) == str:
plaintext = plaintext.decode('UTF-8')
for char in plaintext:
idx = TEXT_MODE.find(char)
if idx != -1:
continue
else:
raise ValueError('Cannot encode char "{0}" inside text mode'.format(char))
if len(plaintext) > MAX_MESSAGE_LENGTH[0x00]:
raise ValueError('Message is too long for text mode (maximum {0} characters)'.format(MAX_MESSAGE_LENGTH[0x00]))
return plaintext
def encodeGsm7(plaintext, discardInvalid=False):
""" GSM-7 text encoding algorithm
Encodes the specified text string into GSM-7 octets (characters). This method does not pack
the characters into septets.
:param text: the text string to encode
:param discardInvalid: if True, characters that cannot be encoded will be silently discarded
:raise ValueError: if the text string cannot be encoded using GSM-7 encoding (unless discardInvalid == True)
:return: A bytearray containing the string encoded in GSM-7 encoding
:rtype: bytearray
"""
result = bytearray()
if PYTHON_VERSION >= 3:
plaintext = str(plaintext)
elif type(plaintext) == str:
plaintext = plaintext.decode('UTF-8')
for char in plaintext:
idx = GSM7_BASIC.find(char)
if idx != -1:
result.append(idx)
elif char in GSM7_EXTENDED:
result.append(0x1B) # ESC - switch to extended table
result.append(ord(GSM7_EXTENDED[char]))
elif not discardInvalid:
raise ValueError('Cannot encode char "{0}" using GSM-7 encoding'.format(char))
return result
def decodeGsm7(encodedText):
""" GSM-7 text decoding algorithm
Decodes the specified GSM-7-encoded string into a plaintext string.
:param encodedText: the text string to encode
:type encodedText: bytearray or str
:return: A string containing the decoded text
:rtype: str
"""
result = []
if type(encodedText) == str:
encodedText = rawStrToByteArray(encodedText) #bytearray(encodedText)
iterEncoded = iter(encodedText)
for b in iterEncoded:
if b == 0x1B: # ESC - switch to extended table
c = chr(next(iterEncoded))
for char, value in dictItemsIter(GSM7_EXTENDED):
if c == value:
result.append(char)
break
else:
result.append(GSM7_BASIC[b])
return ''.join(result)
def divideTextGsm7(plainText):
""" GSM7 message dividing algorithm
Divides text into list of chunks that could be stored in a single, GSM7-encoded SMS message.
:param plainText: the text string to divide
:type plainText: str
:return: A list of strings
:rtype: list of str
"""
result = []
plainStartPtr = 0
plainStopPtr = 0
chunkByteSize = 0
if PYTHON_VERSION >= 3:
plainText = str(plainText)
while plainStopPtr < len(plainText):
char = plainText[plainStopPtr]
idx = GSM7_BASIC.find(char)
if idx != -1:
chunkByteSize = chunkByteSize + 1;
elif char in GSM7_EXTENDED:
chunkByteSize = chunkByteSize + 2;
else:
raise ValueError('Cannot encode char "{0}" using GSM-7 encoding'.format(char))
plainStopPtr = plainStopPtr + 1
if chunkByteSize > MAX_MULTIPART_MESSAGE_LENGTH[0x00]:
plainStopPtr = plainStopPtr - 1
if chunkByteSize >= MAX_MULTIPART_MESSAGE_LENGTH[0x00]:
result.append(plainText[plainStartPtr:plainStopPtr])
plainStartPtr = plainStopPtr
chunkByteSize = 0
if chunkByteSize > 0:
result.append(plainText[plainStartPtr:])
return result
def packSeptets(octets, padBits=0):
""" Packs the specified octets into septets
Typically the output of encodeGsm7 would be used as input to this function. The resulting
bytearray contains the original GSM-7 characters packed into septets ready for transmission.
:rtype: bytearray
"""
result = bytearray()
if type(octets) == str:
octets = iter(rawStrToByteArray(octets))
elif type(octets) == bytearray:
octets = iter(octets)
shift = padBits
if padBits == 0:
try:
prevSeptet = next(octets)
except StopIteration:
return result
else:
prevSeptet = 0x00
for octet in octets:
septet = octet & 0x7f;
if shift == 7:
# prevSeptet has already been fully added to result
shift = 0
prevSeptet = septet
continue
b = ((septet << (7 - shift)) & 0xFF) | (prevSeptet >> shift)
prevSeptet = septet
shift += 1
result.append(b)
if shift != 7:
# There is a bit "left over" from prevSeptet
result.append(prevSeptet >> shift)
return result
def unpackSeptets(septets, numberOfSeptets=None, prevOctet=None, shift=7):
""" Unpacks the specified septets into octets
:param septets: Iterator or iterable containing the septets packed into octets
:type septets: iter(bytearray), bytearray or str
:param numberOfSeptets: The amount of septets to unpack (or None for all remaining in "septets")
:type numberOfSeptets: int or None
:return: The septets unpacked into octets
:rtype: bytearray
"""
result = bytearray()
if type(septets) == str:
septets = iter(rawStrToByteArray(septets))
elif type(septets) == bytearray:
septets = iter(septets)
if numberOfSeptets == None:
numberOfSeptets = MAX_INT # Loop until StopIteration
if numberOfSeptets == 0:
return result
i = 0
for octet in septets:
i += 1
if shift == 7:
shift = 1
if prevOctet != None:
result.append(prevOctet >> 1)
if i <= numberOfSeptets:
result.append(octet & 0x7F)
prevOctet = octet
if i == numberOfSeptets:
break
else:
continue
b = ((octet << shift) & 0x7F) | (prevOctet >> (8 - shift))
prevOctet = octet
result.append(b)
shift += 1
if i == numberOfSeptets:
break
if shift == 7 and prevOctet:
b = prevOctet >> (8 - shift)
if b:
# The final septet value still needs to be unpacked
result.append(b)
return result
def decodeUcs2(byteIter, numBytes):
""" Decodes UCS2-encoded text from the specified byte iterator, up to a maximum of numBytes """
userData = []
i = 0
try:
while i < numBytes:
userData.append(unichr((next(byteIter) << 8) | next(byteIter)))
i += 2
except StopIteration:
# Not enough bytes in iterator to reach numBytes; return what we have
pass
return ''.join(userData)
def encodeUcs2(text):
""" UCS2 text encoding algorithm
Encodes the specified text string into UCS2-encoded bytes.
:param text: the text string to encode
:return: A bytearray containing the string encoded in UCS2 encoding
:rtype: bytearray
"""
result = bytearray()
for b in map(ord, text):
result.append(b >> 8)
result.append(b & 0xFF)
return result
def divideTextUcs2(plainText):
""" UCS-2 message dividing algorithm
Divides text into list of chunks that could be stored in a single, UCS-2 -encoded SMS message.
:param plainText: the text string to divide
:type plainText: str
:return: A list of strings
:rtype: list of str
"""
result = []
resultLength = 0
fullChunksCount = int(len(plainText) / MAX_MULTIPART_MESSAGE_LENGTH[0x08])
for i in range(fullChunksCount):
result.append(plainText[i * MAX_MULTIPART_MESSAGE_LENGTH[0x08] : (i + 1) * MAX_MULTIPART_MESSAGE_LENGTH[0x08]])
resultLength = resultLength + MAX_MULTIPART_MESSAGE_LENGTH[0x08]
# Add last, not fully filled chunk
if resultLength < len(plainText):
result.append(plainText[resultLength:])
return result