M2Crypto.ASN1 — M2Crypto documentation

# Source code for M2Crypto.ASN1

    from __future__ import absolute_import

    """
    M2Crypto wrapper for OpenSSL ASN1 API.

    Copyright (c) 1999-2004 Ng Pheng Siong. All rights reserved.

    Portions created by Open Source Applications Foundation (OSAF) are
    Copyright (C) 2005 OSAF. All Rights Reserved.
    """

    import datetime
    import time

    from M2Crypto import BIO, m2, six
    from typing import Optional  # noqa

    MBSTRING_FLAG = 0x1000
    MBSTRING_ASC = MBSTRING_FLAG | 1
    MBSTRING_BMP = MBSTRING_FLAG | 2

    class ASN1_Integer(object):

        m2_asn1_integer_free = m2.asn1_integer_free

        def __init__(self, asn1int, _pyfree=0):
            # type: (ASN1_Integer, int) -> None
            self.asn1int = asn1int
            self._pyfree = _pyfree

        def __cmp__(self, other):
            # type: (ASN1_Integer) -> int
            if not isinstance(other, ASN1_Integer):
                raise TypeError(
                    "Comparisons supported only between ANS1_Integer objects")

            return m2.asn1_integer_cmp(self.asn1int, other.asn1int)

        def __del__(self):
            # type: () -> None
            if self._pyfree:
                self.m2_asn1_integer_free(self.asn1int)

        def __int__(self):
            # type: () -> int
            return m2.asn1_integer_get(self.asn1int)

    class ASN1_String(object):

        m2_asn1_string_free = m2.asn1_string_free

        def __init__(self, asn1str, _pyfree=0):
            # type: (ASN1_String, int) -> None
            self.asn1str = asn1str
            self._pyfree = _pyfree

        def __bytes__(self):
            # type: () -> bytes
            buf = BIO.MemoryBuffer()
            m2.asn1_string_print(buf.bio_ptr(), self.asn1str)
            return buf.read_all()

        def __str__(self):
            # type: () -> str
            return six.ensure_text(self.__bytes__())

        def __del__(self):
            # type: () -> None
            if getattr(self, '_pyfree', 0):
                self.m2_asn1_string_free(self.asn1str)

        def _ptr(self):
            return self.asn1str

        def as_text(self, flags=0):
            # type: (int) -> str
            """Output an ASN1_STRING structure according to the set flags.

            :param flags: determine the format of the output by using
                   predetermined constants, see ASN1_STRING_print_ex(3)
                   manpage for their meaning.
            :return: output an ASN1_STRING structure.
            """
            buf = BIO.MemoryBuffer()
            m2.asn1_string_print_ex(buf.bio_ptr(), self.asn1str, flags)
            return six.ensure_text(buf.read_all())

    class ASN1_Object(object):

        m2_asn1_object_free = m2.asn1_object_free

        def __init__(self, asn1obj, _pyfree=0):
            # type: (ASN1_Object, int) -> None
            self.asn1obj = asn1obj
            self._pyfree = _pyfree

        def __del__(self):
            # type: () -> None
            if self._pyfree:
                self.m2_asn1_object_free(self.asn1obj)

        def _ptr(self):
            return self.asn1obj

    class _UTC(datetime.tzinfo):
        def tzname(self, dt):
            # type: (Optional[datetime.datetime]) -> str
            return "UTC"

        def dst(self, dt):
            # type: (Optional[datetime.datetime]) -> datetime.timedelta
            return datetime.timedelta(0)

        def utcoffset(self, dt):
            # type: (Optional[datetime.datetime]) -> datetime.timedelta
            return datetime.timedelta(0)

        def __repr__(self):
            return "<Timezone: %s>" % self.tzname(None)

    UTC = _UTC()  # type: _UTC

    class LocalTimezone(datetime.tzinfo):
        """Localtimezone from datetime manual."""

        def __init__(self):
            # type: () -> None
            self._stdoffset = datetime.timedelta(seconds=-time.timezone)
            if time.daylight:
                self._dstoffset = datetime.timedelta(seconds=-time.altzone)
            else:
                self._dstoffset = self._stdoffset
            self._dstdiff = self._dstoffset - self._stdoffset

        def utcoffset(self, dt):
            # type: (datetime.datetime) -> datetime.timedelta
            if self._isdst(dt):
                return self._dstoffset
            else:
                return self._stdoffset

        def dst(self, dt):
            # type: (datetime.datetime) -> datetime.timedelta
            if self._isdst(dt):
                return self._dstdiff
            else:
                return datetime.timedelta(0)

        def tzname(self, dt):
            # type: (datetime.datetime) -> str
            return time.tzname[self._isdst(dt).real]

        def _isdst(self, dt):
            # type: (datetime.datetime) -> bool
            tt = (dt.year, dt.month, dt.day,
                  dt.hour, dt.minute, dt.second,
                  dt.weekday(), 0, -1)
            stamp = time.mktime(tt)
            tt = time.localtime(stamp)
            return tt.tm_isdst > 0

    class ASN1_TIME(object):
        _ssl_months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug",
                       "Sep", "Oct", "Nov", "Dec"]
        m2_asn1_time_free = m2.asn1_time_free

        def __init__(self, asn1_time=None, _pyfree=0, asn1_utctime=None):
            # type: (Optional[ASN1_TIME], Optional[int], Optional[ASN1_TIME]) -> None
            # handle old keyword parameter
            if asn1_time is None:
                asn1_time = asn1_utctime
            if asn1_time is not None:
                assert m2.asn1_time_type_check(asn1_time), \
                    "'asn1_time' type error'"
                self.asn1_time = asn1_time
                self._pyfree = _pyfree
            else:
                self.asn1_time = m2.asn1_time_new()
                self._pyfree = 1

        def __del__(self):
            # type: () -> None
            if getattr(self, '_pyfree', 0):
                self.m2_asn1_time_free(self.asn1_time)

        def __str__(self):
            # type: () -> str
            assert m2.asn1_time_type_check(self.asn1_time), \
                "'asn1_time' type error'"
            buf = BIO.MemoryBuffer()
            m2.asn1_time_print(buf.bio_ptr(), self.asn1_time)
            return six.ensure_text(buf.read_all())

        def _ptr(self):
            assert m2.asn1_time_type_check(self.asn1_time), \
                "'asn1_time' type error'"
            return self.asn1_time

        def set_string(self, string):
            # type: (bytes) -> int
            """Set time from UTC string."""
            assert m2.asn1_time_type_check(self.asn1_time), \
                "'asn1_time' type error'"
            return m2.asn1_time_set_string(self.asn1_time, string)

        def set_time(self, time):
            # type: (int) -> ASN1_TIME
            """Set time from seconds since epoch (int)."""
            assert m2.asn1_time_type_check(self.asn1_time), \
                "'asn1_time' type error'"
            return m2.asn1_time_set(self.asn1_time, time)

        def get_datetime(self):
            # type: () -> ASN1_TIME
            date = str(self)

            timezone = None
            if ' ' not in date:
                raise ValueError("Invalid date: %s" % date)
            month, rest = date.split(' ', 1)
            if month not in self._ssl_months:
                raise ValueError("Invalid date %s: Invalid month: %s" %
                                 (date, month))
            if rest.endswith(' GMT'):
                timezone = UTC
                rest = rest[:-4]
            if '.' in rest:
                dt = datetime.datetime.strptime(rest, "%d %H:%M:%S.%f %Y")
            else:
                dt = datetime.datetime.strptime(rest, "%d %H:%M:%S %Y")
            dt = dt.replace(month=self._ssl_months.index(month) + 1)
            if timezone:
                dt = dt.replace(tzinfo=UTC)
            return dt

        def set_datetime(self, date):
            # type: (datetime.datetime) -> ASN1_TIME
            local = LocalTimezone()
            if date.tzinfo is None:
                date = date.replace(tzinfo=local)
            date = date.astimezone(local)
            return self.set_time(int(time.mktime(date.timetuple())))

    ASN1_UTCTIME = ASN1_TIME