Split ssh_audit.py into separate files (#47).

src/ssh_audit/utils.py

@@ -0,0 +1,165 @@
+"""
+   The MIT License (MIT)
+
+   Copyright (C) 2017-2020 Joe Testa (jtesta@positronsecurity.com)
+   Copyright (C) 2017 Andris Raugulis (moo@arthepsy.eu)
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+"""
+import ipaddress
+import re
+import sys
+
+# pylint: disable=unused-import
+from typing import Dict, List, Set, Sequence, Tuple, Iterable  # noqa: F401
+from typing import Callable, Optional, Union, Any  # noqa: F401
+
+
+class Utils:
+    @classmethod
+    def _type_err(cls, v: Any, target: str) -> TypeError:
+        return TypeError('cannot convert {} to {}'.format(type(v), target))
+
+    @classmethod
+    def to_bytes(cls, v: Union[bytes, str], enc: str = 'utf-8') -> bytes:
+        if isinstance(v, bytes):
+            return v
+        elif isinstance(v, str):
+            return v.encode(enc)
+        raise cls._type_err(v, 'bytes')
+
+    @classmethod
+    def to_text(cls, v: Union[str, bytes], enc: str = 'utf-8') -> str:
+        if isinstance(v, str):
+            return v
+        elif isinstance(v, bytes):
+            return v.decode(enc)
+        raise cls._type_err(v, 'unicode text')
+
+    @classmethod
+    def _is_ascii(cls, v: str, char_filter: Callable[[int], bool] = lambda x: x <= 127) -> bool:
+        r = False
+        if isinstance(v, str):
+            for c in v:
+                i = cls.ctoi(c)
+                if not char_filter(i):
+                    return r
+            r = True
+        return r
+
+    @classmethod
+    def _to_ascii(cls, v: str, char_filter: Callable[[int], bool] = lambda x: x <= 127, errors: str = 'replace') -> str:
+        if isinstance(v, str):
+            r = bytearray()
+            for c in v:
+                i = cls.ctoi(c)
+                if char_filter(i):
+                    r.append(i)
+                else:
+                    if errors == 'ignore':
+                        continue
+                    r.append(63)
+            return cls.to_text(r.decode('ascii'))
+        raise cls._type_err(v, 'ascii')
+
+    @classmethod
+    def is_ascii(cls, v: str) -> bool:
+        return cls._is_ascii(v)
+
+    @classmethod
+    def to_ascii(cls, v: str, errors: str = 'replace') -> str:
+        return cls._to_ascii(v, errors=errors)
+
+    @classmethod
+    def is_print_ascii(cls, v: str) -> bool:
+        return cls._is_ascii(v, lambda x: 126 >= x >= 32)
+
+    @classmethod
+    def to_print_ascii(cls, v: str, errors: str = 'replace') -> str:
+        return cls._to_ascii(v, lambda x: 126 >= x >= 32, errors)
+
+    @classmethod
+    def unique_seq(cls, seq: Sequence[Any]) -> Sequence[Any]:
+        seen = set()  # type: Set[Any]
+
+        def _seen_add(x: Any) -> bool:
+            seen.add(x)
+            return False
+
+        if isinstance(seq, tuple):
+            return tuple(x for x in seq if x not in seen and not _seen_add(x))
+        else:
+            return [x for x in seq if x not in seen and not _seen_add(x)]
+
+    @classmethod
+    def ctoi(cls, c: Union[str, int]) -> int:
+        if isinstance(c, str):
+            return ord(c[0])
+        else:
+            return c
+
+    @staticmethod
+    def parse_int(v: Any) -> int:
+        try:
+            return int(v)
+        except Exception:  # pylint: disable=bare-except
+            return 0
+
+    @staticmethod
+    def parse_float(v: Any) -> float:
+        try:
+            return float(v)
+        except Exception:  # pylint: disable=bare-except
+            return -1.0
+
+    @staticmethod
+    def parse_host_and_port(host_and_port: str) -> Tuple[str, int]:
+        '''Parses a string into a tuple of its host and port.  The port is 0 if not specified.'''
+        host = host_and_port
+        port = 0
+
+        mx = re.match(r'^\[([^\]]+)\](?::(\d+))?$', host_and_port)
+        if mx is not None:
+            host = mx.group(1)
+            port_str = mx.group(2)
+            if port_str is not None:
+                port = int(port_str)
+        else:
+            s = host_and_port.split(':')
+            if len(s) == 2:
+                host = s[0]
+                if len(s[1]) > 0:
+                    port = int(s[1])
+
+        return host, port
+
+    @staticmethod
+    def is_ipv6_address(address: str) -> bool:
+        '''Returns True if address is an IPv6 address, otherwise False.'''
+        is_ipv6 = True
+        try:
+            ipaddress.IPv6Address(address)
+        except ipaddress.AddressValueError:
+            is_ipv6 = False
+
+        return is_ipv6
+
+    @staticmethod
+    def is_windows() -> bool:
+        return sys.platform in ['win32', 'cygwin']