Current File : //opt/alt/python35/lib/python3.5/site-packages/asn1crypto/util.py
# coding: utf-8
"""
Miscellaneous data helpers, including functions for converting integers to and
from bytes and UTC timezone. Exports the following items:
- OrderedDict()
- int_from_bytes()
- int_to_bytes()
- timezone.utc
- inet_ntop()
- inet_pton()
- uri_to_iri()
- iri_to_uri()
"""
from __future__ import unicode_literals, division, absolute_import, print_function
import math
import sys
from datetime import datetime, date, time
from ._errors import unwrap
from ._iri import iri_to_uri, uri_to_iri # noqa
from ._ordereddict import OrderedDict # noqa
from ._types import type_name
if sys.platform == 'win32':
from ._inet import inet_ntop, inet_pton
else:
from socket import inet_ntop, inet_pton # noqa
# Python 2
if sys.version_info <= (3,):
from datetime import timedelta, tzinfo
py2 = True
def int_to_bytes(value, signed=False, width=None):
"""
Converts an integer to a byte string
:param value:
The integer to convert
:param signed:
If the byte string should be encoded using two's complement
:param width:
None == auto, otherwise an integer of the byte width for the return
value
:return:
A byte string
"""
# Handle negatives in two's complement
is_neg = False
if signed and value < 0:
is_neg = True
bits = int(math.ceil(len('%x' % abs(value)) / 2.0) * 8)
value = (value + (1 << bits)) % (1 << bits)
hex_str = '%x' % value
if len(hex_str) & 1:
hex_str = '0' + hex_str
output = hex_str.decode('hex')
if signed and not is_neg and ord(output[0:1]) & 0x80:
output = b'\x00' + output
if width is not None:
if is_neg:
pad_char = b'\xFF'
else:
pad_char = b'\x00'
output = (pad_char * (width - len(output))) + output
elif is_neg and ord(output[0:1]) & 0x80 == 0:
output = b'\xFF' + output
return output
def int_from_bytes(value, signed=False):
"""
Converts a byte string to an integer
:param value:
The byte string to convert
:param signed:
If the byte string should be interpreted using two's complement
:return:
An integer
"""
if value == b'':
return 0
num = long(value.encode("hex"), 16) # noqa
if not signed:
return num
# Check for sign bit and handle two's complement
if ord(value[0:1]) & 0x80:
bit_len = len(value) * 8
return num - (1 << bit_len)
return num
class utc(tzinfo): # noqa
def tzname(self, _):
return b'UTC+00:00'
def utcoffset(self, _):
return timedelta(0)
def dst(self, _):
return timedelta(0)
class timezone(): # noqa
utc = utc()
# Python 3
else:
from datetime import timezone # noqa
py2 = False
def int_to_bytes(value, signed=False, width=None):
"""
Converts an integer to a byte string
:param value:
The integer to convert
:param signed:
If the byte string should be encoded using two's complement
:param width:
None == auto, otherwise an integer of the byte width for the return
value
:return:
A byte string
"""
if width is None:
if signed:
if value < 0:
bits_required = abs(value + 1).bit_length()
else:
bits_required = value.bit_length()
if bits_required % 8 == 0:
bits_required += 1
else:
bits_required = value.bit_length()
width = math.ceil(bits_required / 8) or 1
return value.to_bytes(width, byteorder='big', signed=signed)
def int_from_bytes(value, signed=False):
"""
Converts a byte string to an integer
:param value:
The byte string to convert
:param signed:
If the byte string should be interpreted using two's complement
:return:
An integer
"""
return int.from_bytes(value, 'big', signed=signed)
_DAYS_PER_MONTH_YEAR_0 = {
1: 31,
2: 29, # Year 0 was a leap year
3: 31,
4: 30,
5: 31,
6: 30,
7: 31,
8: 31,
9: 30,
10: 31,
11: 30,
12: 31
}
class extended_date(object):
"""
A datetime.date-like object that can represent the year 0. This is just
to handle 0000-01-01 found in some certificates.
"""
year = None
month = None
day = None
def __init__(self, year, month, day):
"""
:param year:
The integer 0
:param month:
An integer from 1 to 12
:param day:
An integer from 1 to 31
"""
if year != 0:
raise ValueError('year must be 0')
if month < 1 or month > 12:
raise ValueError('month is out of range')
if day < 0 or day > _DAYS_PER_MONTH_YEAR_0[month]:
raise ValueError('day is out of range')
self.year = year
self.month = month
self.day = day
def _format(self, format):
"""
Performs strftime(), always returning a unicode string
:param format:
A strftime() format string
:return:
A unicode string of the formatted date
"""
format = format.replace('%Y', '0000')
# Year 0 is 1BC and a leap year. Leap years repeat themselves
# every 28 years. Because of adjustments and the proleptic gregorian
# calendar, the simplest way to format is to substitute year 2000.
temp = date(2000, self.month, self.day)
if '%c' in format:
c_out = temp.strftime('%c')
# Handle full years
c_out = c_out.replace('2000', '0000')
c_out = c_out.replace('%', '%%')
format = format.replace('%c', c_out)
if '%x' in format:
x_out = temp.strftime('%x')
# Handle formats such as 08/16/2000 or 16.08.2000
x_out = x_out.replace('2000', '0000')
x_out = x_out.replace('%', '%%')
format = format.replace('%x', x_out)
return temp.strftime(format)
def isoformat(self):
"""
Formats the date as %Y-%m-%d
:return:
The date formatted to %Y-%m-%d as a unicode string in Python 3
and a byte string in Python 2
"""
return self.strftime('0000-%m-%d')
def strftime(self, format):
"""
Formats the date using strftime()
:param format:
The strftime() format string
:return:
The formatted date as a unicode string in Python 3 and a byte
string in Python 2
"""
output = self._format(format)
if py2:
return output.encode('utf-8')
return output
def replace(self, year=None, month=None, day=None):
"""
Returns a new datetime.date or asn1crypto.util.extended_date
object with the specified components replaced
:return:
A datetime.date or asn1crypto.util.extended_date object
"""
if year is None:
year = self.year
if month is None:
month = self.month
if day is None:
day = self.day
if year > 0:
cls = date
else:
cls = extended_date
return cls(
year,
month,
day
)
def __str__(self):
if py2:
return self.__bytes__()
else:
return self.__unicode__()
def __bytes__(self):
return self.__unicode__().encode('utf-8')
def __unicode__(self):
return self._format('%Y-%m-%d')
def __eq__(self, other):
if not isinstance(other, self.__class__):
return False
return self.__cmp__(other) == 0
def __ne__(self, other):
return not self.__eq__(other)
def _comparison_error(self, other):
raise TypeError(unwrap(
'''
An asn1crypto.util.extended_date object can only be compared to
an asn1crypto.util.extended_date or datetime.date object, not %s
''',
type_name(other)
))
def __cmp__(self, other):
if isinstance(other, date):
return -1
if not isinstance(other, self.__class__):
self._comparison_error(other)
st = (
self.year,
self.month,
self.day
)
ot = (
other.year,
other.month,
other.day
)
if st < ot:
return -1
if st > ot:
return 1
return 0
def __lt__(self, other):
return self.__cmp__(other) < 0
def __le__(self, other):
return self.__cmp__(other) <= 0
def __gt__(self, other):
return self.__cmp__(other) > 0
def __ge__(self, other):
return self.__cmp__(other) >= 0
class extended_datetime(object):
"""
A datetime.datetime-like object that can represent the year 0. This is just
to handle 0000-01-01 found in some certificates.
"""
year = None
month = None
day = None
hour = None
minute = None
second = None
microsecond = None
tzinfo = None
def __init__(self, year, month, day, hour=0, minute=0, second=0, microsecond=0, tzinfo=None):
"""
:param year:
The integer 0
:param month:
An integer from 1 to 12
:param day:
An integer from 1 to 31
:param hour:
An integer from 0 to 23
:param minute:
An integer from 0 to 59
:param second:
An integer from 0 to 59
:param microsecond:
An integer from 0 to 999999
"""
if year != 0:
raise ValueError('year must be 0')
if month < 1 or month > 12:
raise ValueError('month is out of range')
if day < 0 or day > _DAYS_PER_MONTH_YEAR_0[month]:
raise ValueError('day is out of range')
if hour < 0 or hour > 23:
raise ValueError('hour is out of range')
if minute < 0 or minute > 59:
raise ValueError('minute is out of range')
if second < 0 or second > 59:
raise ValueError('second is out of range')
if microsecond < 0 or microsecond > 999999:
raise ValueError('microsecond is out of range')
self.year = year
self.month = month
self.day = day
self.hour = hour
self.minute = minute
self.second = second
self.microsecond = microsecond
self.tzinfo = tzinfo
def date(self):
"""
:return:
An asn1crypto.util.extended_date of the date
"""
return extended_date(self.year, self.month, self.day)
def time(self):
"""
:return:
A datetime.time object of the time
"""
return time(self.hour, self.minute, self.second, self.microsecond, self.tzinfo)
def utcoffset(self):
"""
:return:
None or a datetime.timedelta() of the offset from UTC
"""
if self.tzinfo is None:
return None
return self.tzinfo.utcoffset(self.replace(year=2000))
def dst(self):
"""
:return:
None or a datetime.timedelta() of the daylight savings time offset
"""
if self.tzinfo is None:
return None
return self.tzinfo.dst(self.replace(year=2000))
def tzname(self):
"""
:return:
None or the name of the timezone as a unicode string in Python 3
and a byte string in Python 2
"""
if self.tzinfo is None:
return None
return self.tzinfo.tzname(self.replace(year=2000))
def _format(self, format):
"""
Performs strftime(), always returning a unicode string
:param format:
A strftime() format string
:return:
A unicode string of the formatted datetime
"""
format = format.replace('%Y', '0000')
# Year 0 is 1BC and a leap year. Leap years repeat themselves
# every 28 years. Because of adjustments and the proleptic gregorian
# calendar, the simplest way to format is to substitute year 2000.
temp = datetime(
2000,
self.month,
self.day,
self.hour,
self.minute,
self.second,
self.microsecond,
self.tzinfo
)
if '%c' in format:
c_out = temp.strftime('%c')
# Handle full years
c_out = c_out.replace('2000', '0000')
c_out = c_out.replace('%', '%%')
format = format.replace('%c', c_out)
if '%x' in format:
x_out = temp.strftime('%x')
# Handle formats such as 08/16/2000 or 16.08.2000
x_out = x_out.replace('2000', '0000')
x_out = x_out.replace('%', '%%')
format = format.replace('%x', x_out)
return temp.strftime(format)
def isoformat(self, sep='T'):
"""
Formats the date as "%Y-%m-%d %H:%M:%S" with the sep param between the
date and time portions
:param set:
A single character of the separator to place between the date and
time
:return:
The formatted datetime as a unicode string in Python 3 and a byte
string in Python 2
"""
if self.microsecond == 0:
return self.strftime('0000-%%m-%%d%s%%H:%%M:%%S' % sep)
return self.strftime('0000-%%m-%%d%s%%H:%%M:%%S.%%f' % sep)
def strftime(self, format):
"""
Formats the date using strftime()
:param format:
The strftime() format string
:return:
The formatted date as a unicode string in Python 3 and a byte
string in Python 2
"""
output = self._format(format)
if py2:
return output.encode('utf-8')
return output
def replace(self, year=None, month=None, day=None, hour=None, minute=None,
second=None, microsecond=None, tzinfo=None):
"""
Returns a new datetime.datetime or asn1crypto.util.extended_datetime
object with the specified components replaced
:return:
A datetime.datetime or asn1crypto.util.extended_datetime object
"""
if year is None:
year = self.year
if month is None:
month = self.month
if day is None:
day = self.day
if hour is None:
hour = self.hour
if minute is None:
minute = self.minute
if second is None:
second = self.second
if microsecond is None:
microsecond = self.microsecond
if tzinfo is None:
tzinfo = self.tzinfo
if year > 0:
cls = datetime
else:
cls = extended_datetime
return cls(
year,
month,
day,
hour,
minute,
second,
microsecond,
tzinfo
)
def __str__(self):
if py2:
return self.__bytes__()
else:
return self.__unicode__()
def __bytes__(self):
return self.__unicode__().encode('utf-8')
def __unicode__(self):
format = '%Y-%m-%d %H:%M:%S'
if self.microsecond != 0:
format += '.%f'
return self._format(format)
def __eq__(self, other):
if not isinstance(other, self.__class__):
return False
return self.__cmp__(other) == 0
def __ne__(self, other):
return not self.__eq__(other)
def _comparison_error(self, other):
"""
Raises a TypeError about the other object not being suitable for
comparison
:param other:
The object being compared to
"""
raise TypeError(unwrap(
'''
An asn1crypto.util.extended_datetime object can only be compared to
an asn1crypto.util.extended_datetime or datetime.datetime object,
not %s
''',
type_name(other)
))
def __cmp__(self, other):
so = self.utcoffset()
oo = other.utcoffset()
if (so is not None and oo is None) or (so is None and oo is not None):
raise TypeError("can't compare offset-naive and offset-aware datetimes")
if isinstance(other, datetime):
return -1
if not isinstance(other, self.__class__):
self._comparison_error(other)
st = (
self.year,
self.month,
self.day,
self.hour,
self.minute,
self.second,
self.microsecond,
so
)
ot = (
other.year,
other.month,
other.day,
other.hour,
other.minute,
other.second,
other.microsecond,
oo
)
if st < ot:
return -1
if st > ot:
return 1
return 0
def __lt__(self, other):
return self.__cmp__(other) < 0
def __le__(self, other):
return self.__cmp__(other) <= 0
def __gt__(self, other):
return self.__cmp__(other) > 0
def __ge__(self, other):
return self.__cmp__(other) >= 0
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