diff --git a/venv/Lib/site-packages/dns/set.py b/venv/Lib/site-packages/dns/set.py new file mode 100644 index 0000000..ae8f0dd --- /dev/null +++ b/venv/Lib/site-packages/dns/set.py @@ -0,0 +1,308 @@ +# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license + +# Copyright (C) 2003-2017 Nominum, Inc. +# +# Permission to use, copy, modify, and distribute this software and its +# documentation for any purpose with or without fee is hereby granted, +# provided that the above copyright notice and this permission notice +# appear in all copies. +# +# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES +# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR +# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT +# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +import itertools + + +class Set: + """A simple set class. + + This class was originally used to deal with python not having a set class, and + originally the class used lists in its implementation. The ordered and indexable + nature of RRsets and Rdatasets is unfortunately widely used in dnspython + applications, so for backwards compatibility sets continue to be a custom class, now + based on an ordered dictionary. + """ + + __slots__ = ["items"] + + def __init__(self, items=None): + """Initialize the set. + + *items*, an iterable or ``None``, the initial set of items. + """ + + self.items = dict() + if items is not None: + for item in items: + # This is safe for how we use set, but if other code + # subclasses it could be a legitimate issue. + self.add(item) # lgtm[py/init-calls-subclass] + + def __repr__(self): + return f"dns.set.Set({repr(list(self.items.keys()))})" # pragma: no cover + + def add(self, item): + """Add an item to the set.""" + + if item not in self.items: + self.items[item] = None + + def remove(self, item): + """Remove an item from the set.""" + + try: + del self.items[item] + except KeyError: + raise ValueError + + def discard(self, item): + """Remove an item from the set if present.""" + + self.items.pop(item, None) + + def pop(self): + """Remove an arbitrary item from the set.""" + (k, _) = self.items.popitem() + return k + + def _clone(self) -> "Set": + """Make a (shallow) copy of the set. + + There is a 'clone protocol' that subclasses of this class + should use. To make a copy, first call your super's _clone() + method, and use the object returned as the new instance. Then + make shallow copies of the attributes defined in the subclass. + + This protocol allows us to write the set algorithms that + return new instances (e.g. union) once, and keep using them in + subclasses. + """ + + if hasattr(self, "_clone_class"): + cls = self._clone_class # type: ignore + else: + cls = self.__class__ + obj = cls.__new__(cls) + obj.items = dict() + obj.items.update(self.items) + return obj + + def __copy__(self): + """Make a (shallow) copy of the set.""" + + return self._clone() + + def copy(self): + """Make a (shallow) copy of the set.""" + + return self._clone() + + def union_update(self, other): + """Update the set, adding any elements from other which are not + already in the set. + """ + + if not isinstance(other, Set): + raise ValueError("other must be a Set instance") + if self is other: # lgtm[py/comparison-using-is] + return + for item in other.items: + self.add(item) + + def intersection_update(self, other): + """Update the set, removing any elements from other which are not + in both sets. + """ + + if not isinstance(other, Set): + raise ValueError("other must be a Set instance") + if self is other: # lgtm[py/comparison-using-is] + return + # we make a copy of the list so that we can remove items from + # the list without breaking the iterator. + for item in list(self.items): + if item not in other.items: + del self.items[item] + + def difference_update(self, other): + """Update the set, removing any elements from other which are in + the set. + """ + + if not isinstance(other, Set): + raise ValueError("other must be a Set instance") + if self is other: # lgtm[py/comparison-using-is] + self.items.clear() + else: + for item in other.items: + self.discard(item) + + def symmetric_difference_update(self, other): + """Update the set, retaining only elements unique to both sets.""" + + if not isinstance(other, Set): + raise ValueError("other must be a Set instance") + if self is other: # lgtm[py/comparison-using-is] + self.items.clear() + else: + overlap = self.intersection(other) + self.union_update(other) + self.difference_update(overlap) + + def union(self, other): + """Return a new set which is the union of ``self`` and ``other``. + + Returns the same Set type as this set. + """ + + obj = self._clone() + obj.union_update(other) + return obj + + def intersection(self, other): + """Return a new set which is the intersection of ``self`` and + ``other``. + + Returns the same Set type as this set. + """ + + obj = self._clone() + obj.intersection_update(other) + return obj + + def difference(self, other): + """Return a new set which ``self`` - ``other``, i.e. the items + in ``self`` which are not also in ``other``. + + Returns the same Set type as this set. + """ + + obj = self._clone() + obj.difference_update(other) + return obj + + def symmetric_difference(self, other): + """Return a new set which (``self`` - ``other``) | (``other`` + - ``self), ie: the items in either ``self`` or ``other`` which + are not contained in their intersection. + + Returns the same Set type as this set. + """ + + obj = self._clone() + obj.symmetric_difference_update(other) + return obj + + def __or__(self, other): + return self.union(other) + + def __and__(self, other): + return self.intersection(other) + + def __add__(self, other): + return self.union(other) + + def __sub__(self, other): + return self.difference(other) + + def __xor__(self, other): + return self.symmetric_difference(other) + + def __ior__(self, other): + self.union_update(other) + return self + + def __iand__(self, other): + self.intersection_update(other) + return self + + def __iadd__(self, other): + self.union_update(other) + return self + + def __isub__(self, other): + self.difference_update(other) + return self + + def __ixor__(self, other): + self.symmetric_difference_update(other) + return self + + def update(self, other): + """Update the set, adding any elements from other which are not + already in the set. + + *other*, the collection of items with which to update the set, which + may be any iterable type. + """ + + for item in other: + self.add(item) + + def clear(self): + """Make the set empty.""" + self.items.clear() + + def __eq__(self, other): + return self.items == other.items + + def __ne__(self, other): + return not self.__eq__(other) + + def __len__(self): + return len(self.items) + + def __iter__(self): + return iter(self.items) + + def __getitem__(self, i): + if isinstance(i, slice): + return list(itertools.islice(self.items, i.start, i.stop, i.step)) + else: + return next(itertools.islice(self.items, i, i + 1)) + + def __delitem__(self, i): + if isinstance(i, slice): + for elt in list(self[i]): + del self.items[elt] + else: + del self.items[self[i]] + + def issubset(self, other): + """Is this set a subset of *other*? + + Returns a ``bool``. + """ + + if not isinstance(other, Set): + raise ValueError("other must be a Set instance") + for item in self.items: + if item not in other.items: + return False + return True + + def issuperset(self, other): + """Is this set a superset of *other*? + + Returns a ``bool``. + """ + + if not isinstance(other, Set): + raise ValueError("other must be a Set instance") + for item in other.items: + if item not in self.items: + return False + return True + + def isdisjoint(self, other): + if not isinstance(other, Set): + raise ValueError("other must be a Set instance") + for item in other.items: + if item in self.items: + return False + return True diff --git a/venv/Lib/site-packages/dns/tokenizer.py b/venv/Lib/site-packages/dns/tokenizer.py new file mode 100644 index 0000000..86ae3e2 --- /dev/null +++ b/venv/Lib/site-packages/dns/tokenizer.py @@ -0,0 +1,706 @@ +# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license + +# Copyright (C) 2003-2017 Nominum, Inc. +# +# Permission to use, copy, modify, and distribute this software and its +# documentation for any purpose with or without fee is hereby granted, +# provided that the above copyright notice and this permission notice +# appear in all copies. +# +# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES +# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR +# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT +# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +"""Tokenize DNS zone file format""" + +import io +import sys +from typing import Any, List, Tuple + +import dns.exception +import dns.name +import dns.ttl + +_DELIMITERS = {" ", "\t", "\n", ";", "(", ")", '"'} +_QUOTING_DELIMITERS = {'"'} + +EOF = 0 +EOL = 1 +WHITESPACE = 2 +IDENTIFIER = 3 +QUOTED_STRING = 4 +COMMENT = 5 +DELIMITER = 6 + + +class UngetBufferFull(dns.exception.DNSException): + """An attempt was made to unget a token when the unget buffer was full.""" + + +class Token: + """A DNS zone file format token. + + ttype: The token type + value: The token value + has_escape: Does the token value contain escapes? + """ + + def __init__( + self, + ttype: int, + value: Any = "", + has_escape: bool = False, + comment: str | None = None, + ): + """Initialize a token instance.""" + + self.ttype = ttype + self.value = value + self.has_escape = has_escape + self.comment = comment + + def is_eof(self) -> bool: + return self.ttype == EOF + + def is_eol(self) -> bool: + return self.ttype == EOL + + def is_whitespace(self) -> bool: + return self.ttype == WHITESPACE + + def is_identifier(self) -> bool: + return self.ttype == IDENTIFIER + + def is_quoted_string(self) -> bool: + return self.ttype == QUOTED_STRING + + def is_comment(self) -> bool: + return self.ttype == COMMENT + + def is_delimiter(self) -> bool: # pragma: no cover (we don't return delimiters yet) + return self.ttype == DELIMITER + + def is_eol_or_eof(self) -> bool: + return self.ttype == EOL or self.ttype == EOF + + def __eq__(self, other): + if not isinstance(other, Token): + return False + return self.ttype == other.ttype and self.value == other.value + + def __ne__(self, other): + if not isinstance(other, Token): + return True + return self.ttype != other.ttype or self.value != other.value + + def __str__(self): + return f'{self.ttype} "{self.value}"' + + def unescape(self) -> "Token": + if not self.has_escape: + return self + unescaped = "" + l = len(self.value) + i = 0 + while i < l: + c = self.value[i] + i += 1 + if c == "\\": + if i >= l: # pragma: no cover (can't happen via get()) + raise dns.exception.UnexpectedEnd + c = self.value[i] + i += 1 + if c.isdigit(): + if i >= l: + raise dns.exception.UnexpectedEnd + c2 = self.value[i] + i += 1 + if i >= l: + raise dns.exception.UnexpectedEnd + c3 = self.value[i] + i += 1 + if not (c2.isdigit() and c3.isdigit()): + raise dns.exception.SyntaxError + codepoint = int(c) * 100 + int(c2) * 10 + int(c3) + if codepoint > 255: + raise dns.exception.SyntaxError + c = chr(codepoint) + unescaped += c + return Token(self.ttype, unescaped) + + def unescape_to_bytes(self) -> "Token": + # We used to use unescape() for TXT-like records, but this + # caused problems as we'd process DNS escapes into Unicode code + # points instead of byte values, and then a to_text() of the + # processed data would not equal the original input. For + # example, \226 in the TXT record would have a to_text() of + # \195\162 because we applied UTF-8 encoding to Unicode code + # point 226. + # + # We now apply escapes while converting directly to bytes, + # avoiding this double encoding. + # + # This code also handles cases where the unicode input has + # non-ASCII code-points in it by converting it to UTF-8. TXT + # records aren't defined for Unicode, but this is the best we + # can do to preserve meaning. For example, + # + # foo\u200bbar + # + # (where \u200b is Unicode code point 0x200b) will be treated + # as if the input had been the UTF-8 encoding of that string, + # namely: + # + # foo\226\128\139bar + # + unescaped = b"" + l = len(self.value) + i = 0 + while i < l: + c = self.value[i] + i += 1 + if c == "\\": + if i >= l: # pragma: no cover (can't happen via get()) + raise dns.exception.UnexpectedEnd + c = self.value[i] + i += 1 + if c.isdigit(): + if i >= l: + raise dns.exception.UnexpectedEnd + c2 = self.value[i] + i += 1 + if i >= l: + raise dns.exception.UnexpectedEnd + c3 = self.value[i] + i += 1 + if not (c2.isdigit() and c3.isdigit()): + raise dns.exception.SyntaxError + codepoint = int(c) * 100 + int(c2) * 10 + int(c3) + if codepoint > 255: + raise dns.exception.SyntaxError + unescaped += b"%c" % (codepoint) + else: + # Note that as mentioned above, if c is a Unicode + # code point outside of the ASCII range, then this + # += is converting that code point to its UTF-8 + # encoding and appending multiple bytes to + # unescaped. + unescaped += c.encode() + else: + unescaped += c.encode() + return Token(self.ttype, bytes(unescaped)) + + +class Tokenizer: + """A DNS zone file format tokenizer. + + A token object is basically a (type, value) tuple. The valid + types are EOF, EOL, WHITESPACE, IDENTIFIER, QUOTED_STRING, + COMMENT, and DELIMITER. + + file: The file to tokenize + + ungotten_char: The most recently ungotten character, or None. + + ungotten_token: The most recently ungotten token, or None. + + multiline: The current multiline level. This value is increased + by one every time a '(' delimiter is read, and decreased by one every time + a ')' delimiter is read. + + quoting: This variable is true if the tokenizer is currently + reading a quoted string. + + eof: This variable is true if the tokenizer has encountered EOF. + + delimiters: The current delimiter dictionary. + + line_number: The current line number + + filename: A filename that will be returned by the where() method. + + idna_codec: A dns.name.IDNACodec, specifies the IDNA + encoder/decoder. If None, the default IDNA 2003 + encoder/decoder is used. + """ + + def __init__( + self, + f: Any = sys.stdin, + filename: str | None = None, + idna_codec: dns.name.IDNACodec | None = None, + ): + """Initialize a tokenizer instance. + + f: The file to tokenize. The default is sys.stdin. + This parameter may also be a string, in which case the tokenizer + will take its input from the contents of the string. + + filename: the name of the filename that the where() method + will return. + + idna_codec: A dns.name.IDNACodec, specifies the IDNA + encoder/decoder. If None, the default IDNA 2003 + encoder/decoder is used. + """ + + if isinstance(f, str): + f = io.StringIO(f) + if filename is None: + filename = "" + elif isinstance(f, bytes): + f = io.StringIO(f.decode()) + if filename is None: + filename = "" + else: + if filename is None: + if f is sys.stdin: + filename = "" + else: + filename = "" + self.file = f + self.ungotten_char: str | None = None + self.ungotten_token: Token | None = None + self.multiline = 0 + self.quoting = False + self.eof = False + self.delimiters = _DELIMITERS + self.line_number = 1 + assert filename is not None + self.filename = filename + if idna_codec is None: + self.idna_codec: dns.name.IDNACodec = dns.name.IDNA_2003 + else: + self.idna_codec = idna_codec + + def _get_char(self) -> str: + """Read a character from input.""" + + if self.ungotten_char is None: + if self.eof: + c = "" + else: + c = self.file.read(1) + if c == "": + self.eof = True + elif c == "\n": + self.line_number += 1 + else: + c = self.ungotten_char + self.ungotten_char = None + return c + + def where(self) -> Tuple[str, int]: + """Return the current location in the input. + + Returns a (string, int) tuple. The first item is the filename of + the input, the second is the current line number. + """ + + return (self.filename, self.line_number) + + def _unget_char(self, c: str) -> None: + """Unget a character. + + The unget buffer for characters is only one character large; it is + an error to try to unget a character when the unget buffer is not + empty. + + c: the character to unget + raises UngetBufferFull: there is already an ungotten char + """ + + if self.ungotten_char is not None: + # this should never happen! + raise UngetBufferFull # pragma: no cover + self.ungotten_char = c + + def skip_whitespace(self) -> int: + """Consume input until a non-whitespace character is encountered. + + The non-whitespace character is then ungotten, and the number of + whitespace characters consumed is returned. + + If the tokenizer is in multiline mode, then newlines are whitespace. + + Returns the number of characters skipped. + """ + + skipped = 0 + while True: + c = self._get_char() + if c != " " and c != "\t": + if (c != "\n") or not self.multiline: + self._unget_char(c) + return skipped + skipped += 1 + + def get(self, want_leading: bool = False, want_comment: bool = False) -> Token: + """Get the next token. + + want_leading: If True, return a WHITESPACE token if the + first character read is whitespace. The default is False. + + want_comment: If True, return a COMMENT token if the + first token read is a comment. The default is False. + + Raises dns.exception.UnexpectedEnd: input ended prematurely + + Raises dns.exception.SyntaxError: input was badly formed + + Returns a Token. + """ + + if self.ungotten_token is not None: + utoken = self.ungotten_token + self.ungotten_token = None + if utoken.is_whitespace(): + if want_leading: + return utoken + elif utoken.is_comment(): + if want_comment: + return utoken + else: + return utoken + skipped = self.skip_whitespace() + if want_leading and skipped > 0: + return Token(WHITESPACE, " ") + token = "" + ttype = IDENTIFIER + has_escape = False + while True: + c = self._get_char() + if c == "" or c in self.delimiters: + if c == "" and self.quoting: + raise dns.exception.UnexpectedEnd + if token == "" and ttype != QUOTED_STRING: + if c == "(": + self.multiline += 1 + self.skip_whitespace() + continue + elif c == ")": + if self.multiline <= 0: + raise dns.exception.SyntaxError + self.multiline -= 1 + self.skip_whitespace() + continue + elif c == '"': + if not self.quoting: + self.quoting = True + self.delimiters = _QUOTING_DELIMITERS + ttype = QUOTED_STRING + continue + else: + self.quoting = False + self.delimiters = _DELIMITERS + self.skip_whitespace() + continue + elif c == "\n": + return Token(EOL, "\n") + elif c == ";": + while 1: + c = self._get_char() + if c == "\n" or c == "": + break + token += c + if want_comment: + self._unget_char(c) + return Token(COMMENT, token) + elif c == "": + if self.multiline: + raise dns.exception.SyntaxError( + "unbalanced parentheses" + ) + return Token(EOF, comment=token) + elif self.multiline: + self.skip_whitespace() + token = "" + continue + else: + return Token(EOL, "\n", comment=token) + else: + # This code exists in case we ever want a + # delimiter to be returned. It never produces + # a token currently. + token = c + ttype = DELIMITER + else: + self._unget_char(c) + break + elif self.quoting and c == "\n": + raise dns.exception.SyntaxError("newline in quoted string") + elif c == "\\": + # + # It's an escape. Put it and the next character into + # the token; it will be checked later for goodness. + # + token += c + has_escape = True + c = self._get_char() + if c == "" or (c == "\n" and not self.quoting): + raise dns.exception.UnexpectedEnd + token += c + if token == "" and ttype != QUOTED_STRING: + if self.multiline: + raise dns.exception.SyntaxError("unbalanced parentheses") + ttype = EOF + return Token(ttype, token, has_escape) + + def unget(self, token: Token) -> None: + """Unget a token. + + The unget buffer for tokens is only one token large; it is + an error to try to unget a token when the unget buffer is not + empty. + + token: the token to unget + + Raises UngetBufferFull: there is already an ungotten token + """ + + if self.ungotten_token is not None: + raise UngetBufferFull + self.ungotten_token = token + + def next(self): + """Return the next item in an iteration. + + Returns a Token. + """ + + token = self.get() + if token.is_eof(): + raise StopIteration + return token + + __next__ = next + + def __iter__(self): + return self + + # Helpers + + def get_int(self, base: int = 10) -> int: + """Read the next token and interpret it as an unsigned integer. + + Raises dns.exception.SyntaxError if not an unsigned integer. + + Returns an int. + """ + + token = self.get().unescape() + if not token.is_identifier(): + raise dns.exception.SyntaxError("expecting an identifier") + if not token.value.isdigit(): + raise dns.exception.SyntaxError("expecting an integer") + return int(token.value, base) + + def get_uint8(self) -> int: + """Read the next token and interpret it as an 8-bit unsigned + integer. + + Raises dns.exception.SyntaxError if not an 8-bit unsigned integer. + + Returns an int. + """ + + value = self.get_int() + if value < 0 or value > 255: + raise dns.exception.SyntaxError(f"{value} is not an unsigned 8-bit integer") + return value + + def get_uint16(self, base: int = 10) -> int: + """Read the next token and interpret it as a 16-bit unsigned + integer. + + Raises dns.exception.SyntaxError if not a 16-bit unsigned integer. + + Returns an int. + """ + + value = self.get_int(base=base) + if value < 0 or value > 65535: + if base == 8: + raise dns.exception.SyntaxError( + f"{value:o} is not an octal unsigned 16-bit integer" + ) + else: + raise dns.exception.SyntaxError( + f"{value} is not an unsigned 16-bit integer" + ) + return value + + def get_uint32(self, base: int = 10) -> int: + """Read the next token and interpret it as a 32-bit unsigned + integer. + + Raises dns.exception.SyntaxError if not a 32-bit unsigned integer. + + Returns an int. + """ + + value = self.get_int(base=base) + if value < 0 or value > 4294967295: + raise dns.exception.SyntaxError( + f"{value} is not an unsigned 32-bit integer" + ) + return value + + def get_uint48(self, base: int = 10) -> int: + """Read the next token and interpret it as a 48-bit unsigned + integer. + + Raises dns.exception.SyntaxError if not a 48-bit unsigned integer. + + Returns an int. + """ + + value = self.get_int(base=base) + if value < 0 or value > 281474976710655: + raise dns.exception.SyntaxError( + f"{value} is not an unsigned 48-bit integer" + ) + return value + + def get_string(self, max_length: int | None = None) -> str: + """Read the next token and interpret it as a string. + + Raises dns.exception.SyntaxError if not a string. + Raises dns.exception.SyntaxError if token value length + exceeds max_length (if specified). + + Returns a string. + """ + + token = self.get().unescape() + if not (token.is_identifier() or token.is_quoted_string()): + raise dns.exception.SyntaxError("expecting a string") + if max_length and len(token.value) > max_length: + raise dns.exception.SyntaxError("string too long") + return token.value + + def get_identifier(self) -> str: + """Read the next token, which should be an identifier. + + Raises dns.exception.SyntaxError if not an identifier. + + Returns a string. + """ + + token = self.get().unescape() + if not token.is_identifier(): + raise dns.exception.SyntaxError("expecting an identifier") + return token.value + + def get_remaining(self, max_tokens: int | None = None) -> List[Token]: + """Return the remaining tokens on the line, until an EOL or EOF is seen. + + max_tokens: If not None, stop after this number of tokens. + + Returns a list of tokens. + """ + + tokens = [] + while True: + token = self.get() + if token.is_eol_or_eof(): + self.unget(token) + break + tokens.append(token) + if len(tokens) == max_tokens: + break + return tokens + + def concatenate_remaining_identifiers(self, allow_empty: bool = False) -> str: + """Read the remaining tokens on the line, which should be identifiers. + + Raises dns.exception.SyntaxError if there are no remaining tokens, + unless `allow_empty=True` is given. + + Raises dns.exception.SyntaxError if a token is seen that is not an + identifier. + + Returns a string containing a concatenation of the remaining + identifiers. + """ + s = "" + while True: + token = self.get().unescape() + if token.is_eol_or_eof(): + self.unget(token) + break + if not token.is_identifier(): + raise dns.exception.SyntaxError + s += token.value + if not (allow_empty or s): + raise dns.exception.SyntaxError("expecting another identifier") + return s + + def as_name( + self, + token: Token, + origin: dns.name.Name | None = None, + relativize: bool = False, + relativize_to: dns.name.Name | None = None, + ) -> dns.name.Name: + """Try to interpret the token as a DNS name. + + Raises dns.exception.SyntaxError if not a name. + + Returns a dns.name.Name. + """ + if not token.is_identifier(): + raise dns.exception.SyntaxError("expecting an identifier") + name = dns.name.from_text(token.value, origin, self.idna_codec) + return name.choose_relativity(relativize_to or origin, relativize) + + def get_name( + self, + origin: dns.name.Name | None = None, + relativize: bool = False, + relativize_to: dns.name.Name | None = None, + ) -> dns.name.Name: + """Read the next token and interpret it as a DNS name. + + Raises dns.exception.SyntaxError if not a name. + + Returns a dns.name.Name. + """ + + token = self.get() + return self.as_name(token, origin, relativize, relativize_to) + + def get_eol_as_token(self) -> Token: + """Read the next token and raise an exception if it isn't EOL or + EOF. + + Returns a string. + """ + + token = self.get() + if not token.is_eol_or_eof(): + raise dns.exception.SyntaxError( + f'expected EOL or EOF, got {token.ttype} "{token.value}"' + ) + return token + + def get_eol(self) -> str: + return self.get_eol_as_token().value + + def get_ttl(self) -> int: + """Read the next token and interpret it as a DNS TTL. + + Raises dns.exception.SyntaxError or dns.ttl.BadTTL if not an + identifier or badly formed. + + Returns an int. + """ + + token = self.get().unescape() + if not token.is_identifier(): + raise dns.exception.SyntaxError("expecting an identifier") + return dns.ttl.from_text(token.value) diff --git a/venv/Lib/site-packages/dns/transaction.py b/venv/Lib/site-packages/dns/transaction.py new file mode 100644 index 0000000..9ecd737 --- /dev/null +++ b/venv/Lib/site-packages/dns/transaction.py @@ -0,0 +1,651 @@ +# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license + +import collections +from typing import Any, Callable, Iterator, List, Tuple + +import dns.exception +import dns.name +import dns.node +import dns.rdata +import dns.rdataclass +import dns.rdataset +import dns.rdatatype +import dns.rrset +import dns.serial +import dns.ttl + + +class TransactionManager: + def reader(self) -> "Transaction": + """Begin a read-only transaction.""" + raise NotImplementedError # pragma: no cover + + def writer(self, replacement: bool = False) -> "Transaction": + """Begin a writable transaction. + + *replacement*, a ``bool``. If `True`, the content of the + transaction completely replaces any prior content. If False, + the default, then the content of the transaction updates the + existing content. + """ + raise NotImplementedError # pragma: no cover + + def origin_information( + self, + ) -> Tuple[dns.name.Name | None, bool, dns.name.Name | None]: + """Returns a tuple + + (absolute_origin, relativize, effective_origin) + + giving the absolute name of the default origin for any + relative domain names, the "effective origin", and whether + names should be relativized. The "effective origin" is the + absolute origin if relativize is False, and the empty name if + relativize is true. (The effective origin is provided even + though it can be computed from the absolute_origin and + relativize setting because it avoids a lot of code + duplication.) + + If the returned names are `None`, then no origin information is + available. + + This information is used by code working with transactions to + allow it to coordinate relativization. The transaction code + itself takes what it gets (i.e. does not change name + relativity). + + """ + raise NotImplementedError # pragma: no cover + + def get_class(self) -> dns.rdataclass.RdataClass: + """The class of the transaction manager.""" + raise NotImplementedError # pragma: no cover + + def from_wire_origin(self) -> dns.name.Name | None: + """Origin to use in from_wire() calls.""" + (absolute_origin, relativize, _) = self.origin_information() + if relativize: + return absolute_origin + else: + return None + + +class DeleteNotExact(dns.exception.DNSException): + """Existing data did not match data specified by an exact delete.""" + + +class ReadOnly(dns.exception.DNSException): + """Tried to write to a read-only transaction.""" + + +class AlreadyEnded(dns.exception.DNSException): + """Tried to use an already-ended transaction.""" + + +def _ensure_immutable_rdataset(rdataset): + if rdataset is None or isinstance(rdataset, dns.rdataset.ImmutableRdataset): + return rdataset + return dns.rdataset.ImmutableRdataset(rdataset) + + +def _ensure_immutable_node(node): + if node is None or node.is_immutable(): + return node + return dns.node.ImmutableNode(node) + + +CheckPutRdatasetType = Callable[ + ["Transaction", dns.name.Name, dns.rdataset.Rdataset], None +] +CheckDeleteRdatasetType = Callable[ + ["Transaction", dns.name.Name, dns.rdatatype.RdataType, dns.rdatatype.RdataType], + None, +] +CheckDeleteNameType = Callable[["Transaction", dns.name.Name], None] + + +class Transaction: + def __init__( + self, + manager: TransactionManager, + replacement: bool = False, + read_only: bool = False, + ): + self.manager = manager + self.replacement = replacement + self.read_only = read_only + self._ended = False + self._check_put_rdataset: List[CheckPutRdatasetType] = [] + self._check_delete_rdataset: List[CheckDeleteRdatasetType] = [] + self._check_delete_name: List[CheckDeleteNameType] = [] + + # + # This is the high level API + # + # Note that we currently use non-immutable types in the return type signature to + # avoid covariance problems, e.g. if the caller has a List[Rdataset], mypy will be + # unhappy if we return an ImmutableRdataset. + + def get( + self, + name: dns.name.Name | str | None, + rdtype: dns.rdatatype.RdataType | str, + covers: dns.rdatatype.RdataType | str = dns.rdatatype.NONE, + ) -> dns.rdataset.Rdataset: + """Return the rdataset associated with *name*, *rdtype*, and *covers*, + or `None` if not found. + + Note that the returned rdataset is immutable. + """ + self._check_ended() + if isinstance(name, str): + name = dns.name.from_text(name, None) + rdtype = dns.rdatatype.RdataType.make(rdtype) + covers = dns.rdatatype.RdataType.make(covers) + rdataset = self._get_rdataset(name, rdtype, covers) + return _ensure_immutable_rdataset(rdataset) + + def get_node(self, name: dns.name.Name) -> dns.node.Node | None: + """Return the node at *name*, if any. + + Returns an immutable node or ``None``. + """ + return _ensure_immutable_node(self._get_node(name)) + + def _check_read_only(self) -> None: + if self.read_only: + raise ReadOnly + + def add(self, *args: Any) -> None: + """Add records. + + The arguments may be: + + - rrset + + - name, rdataset... + + - name, ttl, rdata... + """ + self._check_ended() + self._check_read_only() + self._add(False, args) + + def replace(self, *args: Any) -> None: + """Replace the existing rdataset at the name with the specified + rdataset, or add the specified rdataset if there was no existing + rdataset. + + The arguments may be: + + - rrset + + - name, rdataset... + + - name, ttl, rdata... + + Note that if you want to replace the entire node, you should do + a delete of the name followed by one or more calls to add() or + replace(). + """ + self._check_ended() + self._check_read_only() + self._add(True, args) + + def delete(self, *args: Any) -> None: + """Delete records. + + It is not an error if some of the records are not in the existing + set. + + The arguments may be: + + - rrset + + - name + + - name, rdatatype, [covers] + + - name, rdataset... + + - name, rdata... + """ + self._check_ended() + self._check_read_only() + self._delete(False, args) + + def delete_exact(self, *args: Any) -> None: + """Delete records. + + The arguments may be: + + - rrset + + - name + + - name, rdatatype, [covers] + + - name, rdataset... + + - name, rdata... + + Raises dns.transaction.DeleteNotExact if some of the records + are not in the existing set. + + """ + self._check_ended() + self._check_read_only() + self._delete(True, args) + + def name_exists(self, name: dns.name.Name | str) -> bool: + """Does the specified name exist?""" + self._check_ended() + if isinstance(name, str): + name = dns.name.from_text(name, None) + return self._name_exists(name) + + def update_serial( + self, + value: int = 1, + relative: bool = True, + name: dns.name.Name = dns.name.empty, + ) -> None: + """Update the serial number. + + *value*, an `int`, is an increment if *relative* is `True`, or the + actual value to set if *relative* is `False`. + + Raises `KeyError` if there is no SOA rdataset at *name*. + + Raises `ValueError` if *value* is negative or if the increment is + so large that it would cause the new serial to be less than the + prior value. + """ + self._check_ended() + if value < 0: + raise ValueError("negative update_serial() value") + if isinstance(name, str): + name = dns.name.from_text(name, None) + rdataset = self._get_rdataset(name, dns.rdatatype.SOA, dns.rdatatype.NONE) + if rdataset is None or len(rdataset) == 0: + raise KeyError + if relative: + serial = dns.serial.Serial(rdataset[0].serial) + value + else: + serial = dns.serial.Serial(value) + serial = serial.value # convert back to int + if serial == 0: + serial = 1 + rdata = rdataset[0].replace(serial=serial) + new_rdataset = dns.rdataset.from_rdata(rdataset.ttl, rdata) + self.replace(name, new_rdataset) + + def __iter__(self): + self._check_ended() + return self._iterate_rdatasets() + + def changed(self) -> bool: + """Has this transaction changed anything? + + For read-only transactions, the result is always `False`. + + For writable transactions, the result is `True` if at some time + during the life of the transaction, the content was changed. + """ + self._check_ended() + return self._changed() + + def commit(self) -> None: + """Commit the transaction. + + Normally transactions are used as context managers and commit + or rollback automatically, but it may be done explicitly if needed. + A ``dns.transaction.Ended`` exception will be raised if you try + to use a transaction after it has been committed or rolled back. + + Raises an exception if the commit fails (in which case the transaction + is also rolled back. + """ + self._end(True) + + def rollback(self) -> None: + """Rollback the transaction. + + Normally transactions are used as context managers and commit + or rollback automatically, but it may be done explicitly if needed. + A ``dns.transaction.AlreadyEnded`` exception will be raised if you try + to use a transaction after it has been committed or rolled back. + + Rollback cannot otherwise fail. + """ + self._end(False) + + def check_put_rdataset(self, check: CheckPutRdatasetType) -> None: + """Call *check* before putting (storing) an rdataset. + + The function is called with the transaction, the name, and the rdataset. + + The check function may safely make non-mutating transaction method + calls, but behavior is undefined if mutating transaction methods are + called. The check function should raise an exception if it objects to + the put, and otherwise should return ``None``. + """ + self._check_put_rdataset.append(check) + + def check_delete_rdataset(self, check: CheckDeleteRdatasetType) -> None: + """Call *check* before deleting an rdataset. + + The function is called with the transaction, the name, the rdatatype, + and the covered rdatatype. + + The check function may safely make non-mutating transaction method + calls, but behavior is undefined if mutating transaction methods are + called. The check function should raise an exception if it objects to + the put, and otherwise should return ``None``. + """ + self._check_delete_rdataset.append(check) + + def check_delete_name(self, check: CheckDeleteNameType) -> None: + """Call *check* before putting (storing) an rdataset. + + The function is called with the transaction and the name. + + The check function may safely make non-mutating transaction method + calls, but behavior is undefined if mutating transaction methods are + called. The check function should raise an exception if it objects to + the put, and otherwise should return ``None``. + """ + self._check_delete_name.append(check) + + def iterate_rdatasets( + self, + ) -> Iterator[Tuple[dns.name.Name, dns.rdataset.Rdataset]]: + """Iterate all the rdatasets in the transaction, returning + (`dns.name.Name`, `dns.rdataset.Rdataset`) tuples. + + Note that as is usual with python iterators, adding or removing items + while iterating will invalidate the iterator and may raise `RuntimeError` + or fail to iterate over all entries.""" + self._check_ended() + return self._iterate_rdatasets() + + def iterate_names(self) -> Iterator[dns.name.Name]: + """Iterate all the names in the transaction. + + Note that as is usual with python iterators, adding or removing names + while iterating will invalidate the iterator and may raise `RuntimeError` + or fail to iterate over all entries.""" + self._check_ended() + return self._iterate_names() + + # + # Helper methods + # + + def _raise_if_not_empty(self, method, args): + if len(args) != 0: + raise TypeError(f"extra parameters to {method}") + + def _rdataset_from_args(self, method, deleting, args): + try: + arg = args.popleft() + if isinstance(arg, dns.rrset.RRset): + rdataset = arg.to_rdataset() + elif isinstance(arg, dns.rdataset.Rdataset): + rdataset = arg + else: + if deleting: + ttl = 0 + else: + if isinstance(arg, int): + ttl = arg + if ttl > dns.ttl.MAX_TTL: + raise ValueError(f"{method}: TTL value too big") + else: + raise TypeError(f"{method}: expected a TTL") + arg = args.popleft() + if isinstance(arg, dns.rdata.Rdata): + rdataset = dns.rdataset.from_rdata(ttl, arg) + else: + raise TypeError(f"{method}: expected an Rdata") + return rdataset + except IndexError: + if deleting: + return None + else: + # reraise + raise TypeError(f"{method}: expected more arguments") + + def _add(self, replace, args): + if replace: + method = "replace()" + else: + method = "add()" + try: + args = collections.deque(args) + arg = args.popleft() + if isinstance(arg, str): + arg = dns.name.from_text(arg, None) + if isinstance(arg, dns.name.Name): + name = arg + rdataset = self._rdataset_from_args(method, False, args) + elif isinstance(arg, dns.rrset.RRset): + rrset = arg + name = rrset.name + # rrsets are also rdatasets, but they don't print the + # same and can't be stored in nodes, so convert. + rdataset = rrset.to_rdataset() + else: + raise TypeError( + f"{method} requires a name or RRset as the first argument" + ) + assert rdataset is not None # for type checkers + if rdataset.rdclass != self.manager.get_class(): + raise ValueError(f"{method} has objects of wrong RdataClass") + if rdataset.rdtype == dns.rdatatype.SOA: + (_, _, origin) = self._origin_information() + if name != origin: + raise ValueError(f"{method} has non-origin SOA") + self._raise_if_not_empty(method, args) + if not replace: + existing = self._get_rdataset(name, rdataset.rdtype, rdataset.covers) + if existing is not None: + if isinstance(existing, dns.rdataset.ImmutableRdataset): + trds = dns.rdataset.Rdataset( + existing.rdclass, existing.rdtype, existing.covers + ) + trds.update(existing) + existing = trds + rdataset = existing.union(rdataset) + self._checked_put_rdataset(name, rdataset) + except IndexError: + raise TypeError(f"not enough parameters to {method}") + + def _delete(self, exact, args): + if exact: + method = "delete_exact()" + else: + method = "delete()" + try: + args = collections.deque(args) + arg = args.popleft() + if isinstance(arg, str): + arg = dns.name.from_text(arg, None) + if isinstance(arg, dns.name.Name): + name = arg + if len(args) > 0 and ( + isinstance(args[0], int) or isinstance(args[0], str) + ): + # deleting by type and (optionally) covers + rdtype = dns.rdatatype.RdataType.make(args.popleft()) + if len(args) > 0: + covers = dns.rdatatype.RdataType.make(args.popleft()) + else: + covers = dns.rdatatype.NONE + self._raise_if_not_empty(method, args) + existing = self._get_rdataset(name, rdtype, covers) + if existing is None: + if exact: + raise DeleteNotExact(f"{method}: missing rdataset") + else: + self._checked_delete_rdataset(name, rdtype, covers) + return + else: + rdataset = self._rdataset_from_args(method, True, args) + elif isinstance(arg, dns.rrset.RRset): + rdataset = arg # rrsets are also rdatasets + name = rdataset.name + else: + raise TypeError( + f"{method} requires a name or RRset as the first argument" + ) + self._raise_if_not_empty(method, args) + if rdataset: + if rdataset.rdclass != self.manager.get_class(): + raise ValueError(f"{method} has objects of wrong RdataClass") + existing = self._get_rdataset(name, rdataset.rdtype, rdataset.covers) + if existing is not None: + if exact: + intersection = existing.intersection(rdataset) + if intersection != rdataset: + raise DeleteNotExact(f"{method}: missing rdatas") + rdataset = existing.difference(rdataset) + if len(rdataset) == 0: + self._checked_delete_rdataset( + name, rdataset.rdtype, rdataset.covers + ) + else: + self._checked_put_rdataset(name, rdataset) + elif exact: + raise DeleteNotExact(f"{method}: missing rdataset") + else: + if exact and not self._name_exists(name): + raise DeleteNotExact(f"{method}: name not known") + self._checked_delete_name(name) + except IndexError: + raise TypeError(f"not enough parameters to {method}") + + def _check_ended(self): + if self._ended: + raise AlreadyEnded + + def _end(self, commit): + self._check_ended() + try: + self._end_transaction(commit) + finally: + self._ended = True + + def _checked_put_rdataset(self, name, rdataset): + for check in self._check_put_rdataset: + check(self, name, rdataset) + self._put_rdataset(name, rdataset) + + def _checked_delete_rdataset(self, name, rdtype, covers): + for check in self._check_delete_rdataset: + check(self, name, rdtype, covers) + self._delete_rdataset(name, rdtype, covers) + + def _checked_delete_name(self, name): + for check in self._check_delete_name: + check(self, name) + self._delete_name(name) + + # + # Transactions are context managers. + # + + def __enter__(self): + return self + + def __exit__(self, exc_type, exc_val, exc_tb): + if not self._ended: + if exc_type is None: + self.commit() + else: + self.rollback() + return False + + # + # This is the low level API, which must be implemented by subclasses + # of Transaction. + # + + def _get_rdataset(self, name, rdtype, covers): + """Return the rdataset associated with *name*, *rdtype*, and *covers*, + or `None` if not found. + """ + raise NotImplementedError # pragma: no cover + + def _put_rdataset(self, name, rdataset): + """Store the rdataset.""" + raise NotImplementedError # pragma: no cover + + def _delete_name(self, name): + """Delete all data associated with *name*. + + It is not an error if the name does not exist. + """ + raise NotImplementedError # pragma: no cover + + def _delete_rdataset(self, name, rdtype, covers): + """Delete all data associated with *name*, *rdtype*, and *covers*. + + It is not an error if the rdataset does not exist. + """ + raise NotImplementedError # pragma: no cover + + def _name_exists(self, name): + """Does name exist? + + Returns a bool. + """ + raise NotImplementedError # pragma: no cover + + def _changed(self): + """Has this transaction changed anything?""" + raise NotImplementedError # pragma: no cover + + def _end_transaction(self, commit): + """End the transaction. + + *commit*, a bool. If ``True``, commit the transaction, otherwise + roll it back. + + If committing and the commit fails, then roll back and raise an + exception. + """ + raise NotImplementedError # pragma: no cover + + def _set_origin(self, origin): + """Set the origin. + + This method is called when reading a possibly relativized + source, and an origin setting operation occurs (e.g. $ORIGIN + in a zone file). + """ + raise NotImplementedError # pragma: no cover + + def _iterate_rdatasets(self): + """Return an iterator that yields (name, rdataset) tuples.""" + raise NotImplementedError # pragma: no cover + + def _iterate_names(self): + """Return an iterator that yields a name.""" + raise NotImplementedError # pragma: no cover + + def _get_node(self, name): + """Return the node at *name*, if any. + + Returns a node or ``None``. + """ + raise NotImplementedError # pragma: no cover + + # + # Low-level API with a default implementation, in case a subclass needs + # to override. + # + + def _origin_information(self): + # This is only used by _add() + return self.manager.origin_information() diff --git a/venv/Lib/site-packages/dns/tsig.py b/venv/Lib/site-packages/dns/tsig.py new file mode 100644 index 0000000..333f9aa --- /dev/null +++ b/venv/Lib/site-packages/dns/tsig.py @@ -0,0 +1,359 @@ +# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license + +# Copyright (C) 2001-2007, 2009-2011 Nominum, Inc. +# +# Permission to use, copy, modify, and distribute this software and its +# documentation for any purpose with or without fee is hereby granted, +# provided that the above copyright notice and this permission notice +# appear in all copies. +# +# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES +# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR +# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT +# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +"""DNS TSIG support.""" + +import base64 +import hashlib +import hmac +import struct + +import dns.exception +import dns.name +import dns.rcode +import dns.rdataclass +import dns.rdatatype + + +class BadTime(dns.exception.DNSException): + """The current time is not within the TSIG's validity time.""" + + +class BadSignature(dns.exception.DNSException): + """The TSIG signature fails to verify.""" + + +class BadKey(dns.exception.DNSException): + """The TSIG record owner name does not match the key.""" + + +class BadAlgorithm(dns.exception.DNSException): + """The TSIG algorithm does not match the key.""" + + +class PeerError(dns.exception.DNSException): + """Base class for all TSIG errors generated by the remote peer""" + + +class PeerBadKey(PeerError): + """The peer didn't know the key we used""" + + +class PeerBadSignature(PeerError): + """The peer didn't like the signature we sent""" + + +class PeerBadTime(PeerError): + """The peer didn't like the time we sent""" + + +class PeerBadTruncation(PeerError): + """The peer didn't like amount of truncation in the TSIG we sent""" + + +# TSIG Algorithms + +HMAC_MD5 = dns.name.from_text("HMAC-MD5.SIG-ALG.REG.INT") +HMAC_SHA1 = dns.name.from_text("hmac-sha1") +HMAC_SHA224 = dns.name.from_text("hmac-sha224") +HMAC_SHA256 = dns.name.from_text("hmac-sha256") +HMAC_SHA256_128 = dns.name.from_text("hmac-sha256-128") +HMAC_SHA384 = dns.name.from_text("hmac-sha384") +HMAC_SHA384_192 = dns.name.from_text("hmac-sha384-192") +HMAC_SHA512 = dns.name.from_text("hmac-sha512") +HMAC_SHA512_256 = dns.name.from_text("hmac-sha512-256") +GSS_TSIG = dns.name.from_text("gss-tsig") + +default_algorithm = HMAC_SHA256 + +mac_sizes = { + HMAC_SHA1: 20, + HMAC_SHA224: 28, + HMAC_SHA256: 32, + HMAC_SHA256_128: 16, + HMAC_SHA384: 48, + HMAC_SHA384_192: 24, + HMAC_SHA512: 64, + HMAC_SHA512_256: 32, + HMAC_MD5: 16, + GSS_TSIG: 128, # This is what we assume to be the worst case! +} + + +class GSSTSig: + """ + GSS-TSIG TSIG implementation. This uses the GSS-API context established + in the TKEY message handshake to sign messages using GSS-API message + integrity codes, per the RFC. + + In order to avoid a direct GSSAPI dependency, the keyring holds a ref + to the GSSAPI object required, rather than the key itself. + """ + + def __init__(self, gssapi_context): + self.gssapi_context = gssapi_context + self.data = b"" + self.name = "gss-tsig" + + def update(self, data): + self.data += data + + def sign(self): + # defer to the GSSAPI function to sign + return self.gssapi_context.get_signature(self.data) + + def verify(self, expected): + try: + # defer to the GSSAPI function to verify + return self.gssapi_context.verify_signature(self.data, expected) + except Exception: + # note the usage of a bare exception + raise BadSignature + + +class GSSTSigAdapter: + def __init__(self, keyring): + self.keyring = keyring + + def __call__(self, message, keyname): + if keyname in self.keyring: + key = self.keyring[keyname] + if isinstance(key, Key) and key.algorithm == GSS_TSIG: + if message: + GSSTSigAdapter.parse_tkey_and_step(key, message, keyname) + return key + else: + return None + + @classmethod + def parse_tkey_and_step(cls, key, message, keyname): + # if the message is a TKEY type, absorb the key material + # into the context using step(); this is used to allow the + # client to complete the GSSAPI negotiation before attempting + # to verify the signed response to a TKEY message exchange + try: + rrset = message.find_rrset( + message.answer, keyname, dns.rdataclass.ANY, dns.rdatatype.TKEY + ) + if rrset: + token = rrset[0].key + gssapi_context = key.secret + return gssapi_context.step(token) + except KeyError: + pass + + +class HMACTSig: + """ + HMAC TSIG implementation. This uses the HMAC python module to handle the + sign/verify operations. + """ + + _hashes = { + HMAC_SHA1: hashlib.sha1, + HMAC_SHA224: hashlib.sha224, + HMAC_SHA256: hashlib.sha256, + HMAC_SHA256_128: (hashlib.sha256, 128), + HMAC_SHA384: hashlib.sha384, + HMAC_SHA384_192: (hashlib.sha384, 192), + HMAC_SHA512: hashlib.sha512, + HMAC_SHA512_256: (hashlib.sha512, 256), + HMAC_MD5: hashlib.md5, + } + + def __init__(self, key, algorithm): + try: + hashinfo = self._hashes[algorithm] + except KeyError: + raise NotImplementedError(f"TSIG algorithm {algorithm} is not supported") + + # create the HMAC context + if isinstance(hashinfo, tuple): + self.hmac_context = hmac.new(key, digestmod=hashinfo[0]) + self.size = hashinfo[1] + else: + self.hmac_context = hmac.new(key, digestmod=hashinfo) + self.size = None + self.name = self.hmac_context.name + if self.size: + self.name += f"-{self.size}" + + def update(self, data): + return self.hmac_context.update(data) + + def sign(self): + # defer to the HMAC digest() function for that digestmod + digest = self.hmac_context.digest() + if self.size: + digest = digest[: (self.size // 8)] + return digest + + def verify(self, expected): + # re-digest and compare the results + mac = self.sign() + if not hmac.compare_digest(mac, expected): + raise BadSignature + + +def _digest(wire, key, rdata, time=None, request_mac=None, ctx=None, multi=None): + """Return a context containing the TSIG rdata for the input parameters + @rtype: dns.tsig.HMACTSig or dns.tsig.GSSTSig object + @raises ValueError: I{other_data} is too long + @raises NotImplementedError: I{algorithm} is not supported + """ + + first = not (ctx and multi) + if first: + ctx = get_context(key) + if request_mac: + ctx.update(struct.pack("!H", len(request_mac))) + ctx.update(request_mac) + assert ctx is not None # for type checkers + ctx.update(struct.pack("!H", rdata.original_id)) + ctx.update(wire[2:]) + if first: + ctx.update(key.name.to_digestable()) + ctx.update(struct.pack("!H", dns.rdataclass.ANY)) + ctx.update(struct.pack("!I", 0)) + if time is None: + time = rdata.time_signed + upper_time = (time >> 32) & 0xFFFF + lower_time = time & 0xFFFFFFFF + time_encoded = struct.pack("!HIH", upper_time, lower_time, rdata.fudge) + other_len = len(rdata.other) + if other_len > 65535: + raise ValueError("TSIG Other Data is > 65535 bytes") + if first: + ctx.update(key.algorithm.to_digestable() + time_encoded) + ctx.update(struct.pack("!HH", rdata.error, other_len) + rdata.other) + else: + ctx.update(time_encoded) + return ctx + + +def _maybe_start_digest(key, mac, multi): + """If this is the first message in a multi-message sequence, + start a new context. + @rtype: dns.tsig.HMACTSig or dns.tsig.GSSTSig object + """ + if multi: + ctx = get_context(key) + ctx.update(struct.pack("!H", len(mac))) + ctx.update(mac) + return ctx + else: + return None + + +def sign(wire, key, rdata, time=None, request_mac=None, ctx=None, multi=False): + """Return a (tsig_rdata, mac, ctx) tuple containing the HMAC TSIG rdata + for the input parameters, the HMAC MAC calculated by applying the + TSIG signature algorithm, and the TSIG digest context. + @rtype: (string, dns.tsig.HMACTSig or dns.tsig.GSSTSig object) + @raises ValueError: I{other_data} is too long + @raises NotImplementedError: I{algorithm} is not supported + """ + + ctx = _digest(wire, key, rdata, time, request_mac, ctx, multi) + mac = ctx.sign() + tsig = rdata.replace(time_signed=time, mac=mac) + + return (tsig, _maybe_start_digest(key, mac, multi)) + + +def validate( + wire, key, owner, rdata, now, request_mac, tsig_start, ctx=None, multi=False +): + """Validate the specified TSIG rdata against the other input parameters. + + @raises FormError: The TSIG is badly formed. + @raises BadTime: There is too much time skew between the client and the + server. + @raises BadSignature: The TSIG signature did not validate + @rtype: dns.tsig.HMACTSig or dns.tsig.GSSTSig object""" + + (adcount,) = struct.unpack("!H", wire[10:12]) + if adcount == 0: + raise dns.exception.FormError + adcount -= 1 + new_wire = wire[0:10] + struct.pack("!H", adcount) + wire[12:tsig_start] + if rdata.error != 0: + if rdata.error == dns.rcode.BADSIG: + raise PeerBadSignature + elif rdata.error == dns.rcode.BADKEY: + raise PeerBadKey + elif rdata.error == dns.rcode.BADTIME: + raise PeerBadTime + elif rdata.error == dns.rcode.BADTRUNC: + raise PeerBadTruncation + else: + raise PeerError(f"unknown TSIG error code {rdata.error}") + if abs(rdata.time_signed - now) > rdata.fudge: + raise BadTime + if key.name != owner: + raise BadKey + if key.algorithm != rdata.algorithm: + raise BadAlgorithm + ctx = _digest(new_wire, key, rdata, None, request_mac, ctx, multi) + ctx.verify(rdata.mac) + return _maybe_start_digest(key, rdata.mac, multi) + + +def get_context(key): + """Returns an HMAC context for the specified key. + + @rtype: HMAC context + @raises NotImplementedError: I{algorithm} is not supported + """ + + if key.algorithm == GSS_TSIG: + return GSSTSig(key.secret) + else: + return HMACTSig(key.secret, key.algorithm) + + +class Key: + def __init__( + self, + name: dns.name.Name | str, + secret: bytes | str, + algorithm: dns.name.Name | str = default_algorithm, + ): + if isinstance(name, str): + name = dns.name.from_text(name) + self.name = name + if isinstance(secret, str): + secret = base64.decodebytes(secret.encode()) + self.secret = secret + if isinstance(algorithm, str): + algorithm = dns.name.from_text(algorithm) + self.algorithm = algorithm + + def __eq__(self, other): + return ( + isinstance(other, Key) + and self.name == other.name + and self.secret == other.secret + and self.algorithm == other.algorithm + ) + + def __repr__(self): + r = f" Dict[dns.name.Name, Any]: + """Convert a dictionary containing (textual DNS name, base64 secret) + pairs into a binary keyring which has (dns.name.Name, bytes) pairs, or + a dictionary containing (textual DNS name, (algorithm, base64 secret)) + pairs into a binary keyring which has (dns.name.Name, dns.tsig.Key) pairs. + @rtype: dict""" + + keyring: Dict[dns.name.Name, Any] = {} + for name, value in textring.items(): + kname = dns.name.from_text(name) + if isinstance(value, str): + keyring[kname] = dns.tsig.Key(kname, value).secret + else: + (algorithm, secret) = value + keyring[kname] = dns.tsig.Key(kname, secret, algorithm) + return keyring + + +def to_text(keyring: Dict[dns.name.Name, Any]) -> Dict[str, Any]: + """Convert a dictionary containing (dns.name.Name, dns.tsig.Key) pairs + into a text keyring which has (textual DNS name, (textual algorithm, + base64 secret)) pairs, or a dictionary containing (dns.name.Name, bytes) + pairs into a text keyring which has (textual DNS name, base64 secret) pairs. + @rtype: dict""" + + textring = {} + + def b64encode(secret): + return base64.encodebytes(secret).decode().rstrip() + + for name, key in keyring.items(): + tname = name.to_text() + if isinstance(key, bytes): + textring[tname] = b64encode(key) + else: + if isinstance(key.secret, bytes): + text_secret = b64encode(key.secret) + else: + text_secret = str(key.secret) + + textring[tname] = (key.algorithm.to_text(), text_secret) + return textring