1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
# -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd
# Copyright 2020 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import itertools
import random
import re
import string
from collections.abc import Iterable
from typing import Optional, Tuple
from synapse.api.errors import Codes, SynapseError
_string_with_symbols = string.digits + string.ascii_letters + ".,;:^&*-_+=#~@"
# https://matrix.org/docs/spec/client_server/r0.6.0#post-matrix-client-r0-register-email-requesttoken
client_secret_regex = re.compile(r"^[0-9a-zA-Z\.\=\_\-]+$")
# https://matrix.org/docs/spec/client_server/r0.6.1#matrix-content-mxc-uris,
# together with https://github.com/matrix-org/matrix-doc/issues/2177 which basically
# says "there is no grammar for media ids"
#
# The server_name part of this is purposely lax: use parse_and_validate_mxc for
# additional validation.
#
MXC_REGEX = re.compile("^mxc://([^/]+)/([^/#?]+)$")
# random_string and random_string_with_symbols are used for a range of things,
# some cryptographically important, some less so. We use SystemRandom to make sure
# we get cryptographically-secure randoms.
rand = random.SystemRandom()
def random_string(length):
return "".join(rand.choice(string.ascii_letters) for _ in range(length))
def random_string_with_symbols(length):
return "".join(rand.choice(_string_with_symbols) for _ in range(length))
def is_ascii(s):
if isinstance(s, bytes):
try:
s.decode("ascii").encode("ascii")
except UnicodeDecodeError:
return False
except UnicodeEncodeError:
return False
return True
def assert_valid_client_secret(client_secret):
"""Validate that a given string matches the client_secret regex defined by the spec"""
if client_secret_regex.match(client_secret) is None:
raise SynapseError(
400, "Invalid client_secret parameter", errcode=Codes.INVALID_PARAM
)
def parse_server_name(server_name: str) -> Tuple[str, Optional[int]]:
"""Split a server name into host/port parts.
Args:
server_name: server name to parse
Returns:
host/port parts.
Raises:
ValueError if the server name could not be parsed.
"""
try:
if server_name[-1] == "]":
# ipv6 literal, hopefully
return server_name, None
domain_port = server_name.rsplit(":", 1)
domain = domain_port[0]
port = int(domain_port[1]) if domain_port[1:] else None
return domain, port
except Exception:
raise ValueError("Invalid server name '%s'" % server_name)
VALID_HOST_REGEX = re.compile("\\A[0-9a-zA-Z.-]+\\Z")
def parse_and_validate_server_name(server_name: str) -> Tuple[str, Optional[int]]:
"""Split a server name into host/port parts and do some basic validation.
Args:
server_name: server name to parse
Returns:
host/port parts.
Raises:
ValueError if the server name could not be parsed.
"""
host, port = parse_server_name(server_name)
# these tests don't need to be bulletproof as we'll find out soon enough
# if somebody is giving us invalid data. What we *do* need is to be sure
# that nobody is sneaking IP literals in that look like hostnames, etc.
# look for ipv6 literals
if host[0] == "[":
if host[-1] != "]":
raise ValueError("Mismatched [...] in server name '%s'" % (server_name,))
return host, port
# otherwise it should only be alphanumerics.
if not VALID_HOST_REGEX.match(host):
raise ValueError(
"Server name '%s' contains invalid characters" % (server_name,)
)
return host, port
def parse_and_validate_mxc_uri(mxc: str) -> Tuple[str, Optional[int], str]:
"""Parse the given string as an MXC URI
Checks that the "server name" part is a valid server name
Args:
mxc: the (alleged) MXC URI to be checked
Returns:
hostname, port, media id
Raises:
ValueError if the URI cannot be parsed
"""
m = MXC_REGEX.match(mxc)
if not m:
raise ValueError("mxc URI %r did not match expected format" % (mxc,))
server_name = m.group(1)
media_id = m.group(2)
host, port = parse_and_validate_server_name(server_name)
return host, port, media_id
def shortstr(iterable: Iterable, maxitems: int = 5) -> str:
"""If iterable has maxitems or fewer, return the stringification of a list
containing those items.
Otherwise, return the stringification of a a list with the first maxitems items,
followed by "...".
Args:
iterable: iterable to truncate
maxitems: number of items to return before truncating
"""
items = list(itertools.islice(iterable, maxitems + 1))
if len(items) <= maxitems:
return str(items)
return "[" + ", ".join(repr(r) for r in items[:maxitems]) + ", ...]"
def strtobool(val: str) -> bool:
"""Convert a string representation of truth to True or False
True values are 'y', 'yes', 't', 'true', 'on', and '1'; false values
are 'n', 'no', 'f', 'false', 'off', and '0'. Raises ValueError if
'val' is anything else.
This is lifted from distutils.util.strtobool, with the exception that it actually
returns a bool, rather than an int.
"""
val = val.lower()
if val in ("y", "yes", "t", "true", "on", "1"):
return True
elif val in ("n", "no", "f", "false", "off", "0"):
return False
else:
raise ValueError("invalid truth value %r" % (val,))
|
