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comparison libervia/backend/tools/web.py @ 4071:4b842c1fb686

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refactoring: renamed `sat` package to `libervia.backend`
author Goffi <goffi@goffi.org>
date Fri, 02 Jun 2023 11:49:51 +0200
parents sat/tools/web.py@524856bd7b19
children 0d7bb4df2343
comparison
equal deleted inserted replaced
4070:d10748475025 4071:4b842c1fb686
1 #!/usr/bin/env python3
2
3 # Libervia: an XMPP client
4 # Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
5
6 # This program is free software: you can redistribute it and/or modify
7 # it under the terms of the GNU Affero General Public License as published by
8 # the Free Software Foundation, either version 3 of the License, or
9 # (at your option) any later version.
10
11 # This program is distributed in the hope that it will be useful,
12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 # GNU Affero General Public License for more details.
15
16 # You should have received a copy of the GNU Affero General Public License
17 # along with this program. If not, see <http://www.gnu.org/licenses/>.
18
19 from typing import Optional, Union
20 from pathlib import Path
21 from io import BufferedIOBase
22
23 from OpenSSL import SSL
24 import treq
25 from treq.client import HTTPClient
26 from twisted.internet import reactor, ssl
27 from twisted.internet.interfaces import IOpenSSLClientConnectionCreator
28 from twisted.web import iweb
29 from twisted.web import client as http_client
30 from zope.interface import implementer
31
32 from libervia.backend.core import exceptions
33 from libervia.backend.core.log import getLogger
34
35
36 log = getLogger(__name__)
37
38
39 SSLError = SSL.Error
40
41
42 @implementer(IOpenSSLClientConnectionCreator)
43 class NoCheckConnectionCreator(object):
44 def __init__(self, hostname, ctx):
45 self._ctx = ctx
46
47 def clientConnectionForTLS(self, tlsProtocol):
48 context = self._ctx
49 connection = SSL.Connection(context, None)
50 connection.set_app_data(tlsProtocol)
51 return connection
52
53
54 @implementer(iweb.IPolicyForHTTPS)
55 class NoCheckContextFactory:
56 """Context factory which doesn't do TLS certificate check
57
58 /!\\ it's obvisously a security flaw to use this class,
59 and it should be used only with explicit agreement from the end used
60 """
61
62 def creatorForNetloc(self, hostname, port):
63 log.warning(
64 "TLS check disabled for {host} on port {port}".format(
65 host=hostname, port=port
66 )
67 )
68 certificateOptions = ssl.CertificateOptions(trustRoot=None)
69 return NoCheckConnectionCreator(hostname, certificateOptions.getContext())
70
71
72 #: following treq doesn't check TLS, obviously it is unsecure and should not be used
73 #: without explicit warning
74 treq_client_no_ssl = HTTPClient(http_client.Agent(reactor, NoCheckContextFactory()))
75
76
77 async def download_file(
78 url: str,
79 dest: Union[str, Path, BufferedIOBase],
80 max_size: Optional[int] = None
81 ) -> None:
82 """Helper method to download a file
83
84 This is for internal download, for high level download with progression, use
85 ``plugin_misc_download``.
86
87 Inspired from
88 https://treq.readthedocs.io/en/latest/howto.html#handling-streaming-responses
89
90 @param dest: destination filename or file-like object
91 of it's a file-like object, you'll have to close it yourself
92 @param max_size: if set, an exceptions.DataError will be raised if the downloaded file
93 is bigger that given value (in bytes).
94 """
95 if isinstance(dest, BufferedIOBase):
96 f = dest
97 must_close = False
98 else:
99 dest = Path(dest)
100 f = dest.open("wb")
101 must_close = True
102 d = treq.get(url, unbuffered=True)
103 written = 0
104
105 def write(data: bytes):
106 if max_size is not None:
107 nonlocal written
108 written += len(data)
109 if written > max_size:
110 raise exceptions.DataError(
111 "downloaded file is bigger than expected ({max_size})"
112 )
113 f.write(data)
114
115 d.addCallback(treq.collect, f.write)
116 try:
117 await d
118 except exceptions.DataError as e:
119 log.warning("download cancelled due to file oversized")
120 raise e
121 except Exception as e:
122 log.error(f"Can't write file {dest}: {e}")
123 raise e
124 finally:
125 if must_close:
126 f.close()