0
0
mirror of https://github.com/python/cpython.git synced 2024-11-27 23:47:29 +01:00
cpython/Lib/email/errors.py
Petr Viktorin 0976339818
gh-121650: Encode newlines in headers, and verify headers are sound (GH-122233)
## Encode header parts that contain newlines

Per RFC 2047:

> [...] these encoding schemes allow the
> encoding of arbitrary octet values, mail readers that implement this
> decoding should also ensure that display of the decoded data on the
> recipient's terminal will not cause unwanted side-effects

It seems that the "quoted-word" scheme is a valid way to include
a newline character in a header value, just like we already allow
undecodable bytes or control characters.
They do need to be properly quoted when serialized to text, though.


## Verify that email headers are well-formed

This should fail for custom fold() implementations that aren't careful
about newlines.


Co-authored-by: Bas Bloemsaat <bas@bloemsaat.org>
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
2024-07-31 00:19:48 +02:00

118 lines
3.7 KiB
Python

# Copyright (C) 2001-2006 Python Software Foundation
# Author: Barry Warsaw
# Contact: email-sig@python.org
"""email package exception classes."""
class MessageError(Exception):
"""Base class for errors in the email package."""
class MessageParseError(MessageError):
"""Base class for message parsing errors."""
class HeaderParseError(MessageParseError):
"""Error while parsing headers."""
class BoundaryError(MessageParseError):
"""Couldn't find terminating boundary."""
class MultipartConversionError(MessageError, TypeError):
"""Conversion to a multipart is prohibited."""
class CharsetError(MessageError):
"""An illegal charset was given."""
class HeaderWriteError(MessageError):
"""Error while writing headers."""
# These are parsing defects which the parser was able to work around.
class MessageDefect(ValueError):
"""Base class for a message defect."""
def __init__(self, line=None):
if line is not None:
super().__init__(line)
self.line = line
class NoBoundaryInMultipartDefect(MessageDefect):
"""A message claimed to be a multipart but had no boundary parameter."""
class StartBoundaryNotFoundDefect(MessageDefect):
"""The claimed start boundary was never found."""
class CloseBoundaryNotFoundDefect(MessageDefect):
"""A start boundary was found, but not the corresponding close boundary."""
class FirstHeaderLineIsContinuationDefect(MessageDefect):
"""A message had a continuation line as its first header line."""
class MisplacedEnvelopeHeaderDefect(MessageDefect):
"""A 'Unix-from' header was found in the middle of a header block."""
class MissingHeaderBodySeparatorDefect(MessageDefect):
"""Found line with no leading whitespace and no colon before blank line."""
# XXX: backward compatibility, just in case (it was never emitted).
MalformedHeaderDefect = MissingHeaderBodySeparatorDefect
class MultipartInvariantViolationDefect(MessageDefect):
"""A message claimed to be a multipart but no subparts were found."""
class InvalidMultipartContentTransferEncodingDefect(MessageDefect):
"""An invalid content transfer encoding was set on the multipart itself."""
class UndecodableBytesDefect(MessageDefect):
"""Header contained bytes that could not be decoded"""
class InvalidBase64PaddingDefect(MessageDefect):
"""base64 encoded sequence had an incorrect length"""
class InvalidBase64CharactersDefect(MessageDefect):
"""base64 encoded sequence had characters not in base64 alphabet"""
class InvalidBase64LengthDefect(MessageDefect):
"""base64 encoded sequence had invalid length (1 mod 4)"""
# These errors are specific to header parsing.
class HeaderDefect(MessageDefect):
"""Base class for a header defect."""
def __init__(self, *args, **kw):
super().__init__(*args, **kw)
class InvalidHeaderDefect(HeaderDefect):
"""Header is not valid, message gives details."""
class HeaderMissingRequiredValue(HeaderDefect):
"""A header that must have a value had none"""
class NonPrintableDefect(HeaderDefect):
"""ASCII characters outside the ascii-printable range found"""
def __init__(self, non_printables):
super().__init__(non_printables)
self.non_printables = non_printables
def __str__(self):
return ("the following ASCII non-printables found in header: "
"{}".format(self.non_printables))
class ObsoleteHeaderDefect(HeaderDefect):
"""Header uses syntax declared obsolete by RFC 5322"""
class NonASCIILocalPartDefect(HeaderDefect):
"""local_part contains non-ASCII characters"""
# This defect only occurs during unicode parsing, not when
# parsing messages decoded from binary.
class InvalidDateDefect(HeaderDefect):
"""Header has unparsable or invalid date"""