path: root/nbxmpp/stringprepare.py

# -*- coding:utf-8 -*-
## src/common/xmpp/stringprepare.py
##
## Copyright (C) 2001-2005 Twisted Matrix Laboratories
## Copyright (C) 2005-2012 Yann Leboulanger <asterix AT lagaule.org>
## Copyright (C) 2006 Stefan Bethge <stefan AT lanpartei.de>
## Copyright (C) 2007 Jean-Marie Traissard <jim AT lapin.org>
##
## This file is part of Gajim.
##
## Gajim 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; version 3 only.
##
## Gajim 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 Gajim. If not, see <http://www.gnu.org/licenses/>.
##

import stringprep
import unicodedata
from encodings import idna


class ILookupTable:
    """
    Interface for character lookup classes
    """

    def lookup(self, c):
        """
        Return whether character is in this table
        """


class IMappingTable:
    """
    Interface for character mapping classes
    """

    def map(self, c):
        """
        Return mapping for character
        """


class LookupTableFromFunction:
    __implements__ = ILookupTable

    def __init__(self, in_table_function):
        self.lookup = in_table_function


class LookupTable:
    __implements__ = ILookupTable

    def __init__(self, table):
        self._table = table

    def lookup(self, c):
        return c in self._table


class MappingTableFromFunction:
    __implements__ = IMappingTable

    def __init__(self, map_table_function):
        self.map = map_table_function


class EmptyMappingTable:
    __implements__ = IMappingTable

    def __init__(self, in_table_function):
        self._in_table_function = in_table_function

    def map(self, c):
        if self._in_table_function(c):
            return None
        return c


class Profile:
    def __init__(self, mappings=None, normalize=True, prohibiteds=None,
                 check_unassigneds=True, check_bidi=True):
        if mappings is None:
            self.mappings = []
        else:
            self.mappings = mappings

        self.normalize = normalize

        if prohibiteds is None:
            self.prohibiteds = []
        else:
            self.prohibiteds = prohibiteds

        self.do_check_unassigneds = check_unassigneds
        self.do_check_bidi = check_bidi

    def prepare(self, string):
        result = self.map(string)
        if self.normalize:
            result = unicodedata.normalize("NFKC", result)
        self.check_prohibiteds(result)
        if self.do_check_unassigneds:
            self.check_unassigneds(result)
        if self.do_check_bidi:
            self.check_bidirectionals(result)
        return result

    def map(self, string):
        result = []

        for c in string:
            result_c = c

            for mapping in self.mappings:
                result_c = mapping.map(c)
                if result_c != c:
                    break

            if result_c is not None:
                result.append(result_c)

        return "".join(result)

    def check_prohibiteds(self, string):
        for c in string:
            for table in self.prohibiteds:
                if table.lookup(c):
                    raise UnicodeError("Invalid character %s" % repr(c))

    def check_unassigneds(self, string):
        for c in string:
            if stringprep.in_table_a1(c):
                raise UnicodeError("Unassigned code point %s" % repr(c))

    def check_bidirectionals(self, string):
        found_LCat = False
        found_RandALCat = False

        for c in string:
            if stringprep.in_table_d1(c):
                found_RandALCat = True
            if stringprep.in_table_d2(c):
                found_LCat = True

        if found_LCat and found_RandALCat:
            raise UnicodeError("Violation of BIDI Requirement 2")

        if found_RandALCat and not (stringprep.in_table_d1(string[0]) and
                                                                stringprep.in_table_d1(string[-1])):
            raise UnicodeError("Violation of BIDI Requirement 3")


class NamePrep:
    """
    Implements preparation of internationalized domain names

    This class implements preparing internationalized domain names using the
    rules defined in RFC 3491, section 4 (Conversion operations).

    We do not perform step 4 since we deal with unicode representations of
    domain names and do not convert from or to ASCII representations using
    punycode encoding. When such a conversion is needed, the L{idna} standard
    library provides the C{ToUnicode()} and C{ToASCII()} functions. Note that
    L{idna} itself assumes UseSTD3ASCIIRules to be false.

    The following steps are performed by C{prepare()}:

            * Split the domain name in labels at the dots (RFC 3490, 3.1)
            * Apply nameprep proper on each label (RFC 3491)
            * Enforce the restrictions on ASCII characters in host names by
                    assuming STD3ASCIIRules to be true. (STD 3)
            * Rejoin the labels using the label separator U+002E (full stop).
    """

    # Prohibited characters.
    prohibiteds = [chr(n) for n in list(range(0x00, 0x2c + 1)) +
                                                                            list(range(0x2e, 0x2f + 1)) +
                                                                            list(range(0x3a, 0x40 + 1)) +
                                                                            list(range(0x5b, 0x60 + 1)) +
                                                                            list(range(0x7b, 0x7f + 1)) ]

    def prepare(self, string):
        result = []

        labels = idna.dots.split(string)

        if labels and len(labels[-1]) == 0:
            trailing_dot = '.'
            del labels[-1]
        else:
            trailing_dot = ''

        for label in labels:
            result.append(self.nameprep(label))

        return ".".join(result)+trailing_dot

    def check_prohibiteds(self, string):
        for c in string:
            if c in self.prohibiteds:
                raise UnicodeError("Invalid character %s" % repr(c))

    def nameprep(self, label):
        label = idna.nameprep(label)
        self.check_prohibiteds(label)
        if len(label) == 0:
            raise UnicodeError("Invalid empty name")
        if label[0] == '-':
            raise UnicodeError("Invalid leading hyphen-minus")
        if label[-1] == '-':
            raise UnicodeError("Invalid trailing hyphen-minus")
        return label

C_11 = LookupTableFromFunction(stringprep.in_table_c11)
C_12 = LookupTableFromFunction(stringprep.in_table_c12)
C_21 = LookupTableFromFunction(stringprep.in_table_c21)
C_22 = LookupTableFromFunction(stringprep.in_table_c22)
C_3 = LookupTableFromFunction(stringprep.in_table_c3)
C_4 = LookupTableFromFunction(stringprep.in_table_c4)
C_5 = LookupTableFromFunction(stringprep.in_table_c5)
C_6 = LookupTableFromFunction(stringprep.in_table_c6)
C_7 = LookupTableFromFunction(stringprep.in_table_c7)
C_8 = LookupTableFromFunction(stringprep.in_table_c8)
C_9 = LookupTableFromFunction(stringprep.in_table_c9)

B_1 = EmptyMappingTable(stringprep.in_table_b1)
B_2 = MappingTableFromFunction(stringprep.map_table_b2)

nodeprep = Profile(mappings=[B_1, B_2],
                                                prohibiteds=[C_11, C_12, C_21, C_22,
                                                                                C_3, C_4, C_5, C_6, C_7, C_8, C_9,
                                                                                LookupTable(['"', '&', "'", '/',
                                                                                                                ':', '<', '>', '@'])])

resourceprep = Profile(mappings=[B_1,],
                                                        prohibiteds=[C_12, C_21, C_22,
                                                                                        C_3, C_4, C_5, C_6, C_7, C_8, C_9])

nameprep = NamePrep()