This file is indexed.

/usr/lib/python2.7/dist-packages/paramiko/util.py is in python-paramiko 1.15.1-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  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
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
# Copyright (C) 2003-2007  Robey Pointer <robeypointer@gmail.com>
#
# This file is part of paramiko.
#
# Paramiko is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation; either version 2.1 of the License, or (at your option)
# any later version.
#
# Paramiko is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.

"""
Useful functions used by the rest of paramiko.
"""

from __future__ import generators

import array
from binascii import hexlify, unhexlify
import errno
import sys
import struct
import traceback
import threading
import logging

from paramiko.common import DEBUG, zero_byte, xffffffff, max_byte
from paramiko.py3compat import PY2, long, byte_ord, b, byte_chr
from paramiko.config import SSHConfig


def inflate_long(s, always_positive=False):
    """turns a normalized byte string into a long-int (adapted from Crypto.Util.number)"""
    out = long(0)
    negative = 0
    if not always_positive and (len(s) > 0) and (byte_ord(s[0]) >= 0x80):
        negative = 1
    if len(s) % 4:
        filler = zero_byte
        if negative:
            filler = max_byte
        # never convert this to ``s +=`` because this is a string, not a number
        # noinspection PyAugmentAssignment
        s = filler * (4 - len(s) % 4) + s
    for i in range(0, len(s), 4):
        out = (out << 32) + struct.unpack('>I', s[i:i+4])[0]
    if negative:
        out -= (long(1) << (8 * len(s)))
    return out

deflate_zero = zero_byte if PY2 else 0
deflate_ff = max_byte if PY2 else 0xff


def deflate_long(n, add_sign_padding=True):
    """turns a long-int into a normalized byte string (adapted from Crypto.Util.number)"""
    # after much testing, this algorithm was deemed to be the fastest
    s = bytes()
    n = long(n)
    while (n != 0) and (n != -1):
        s = struct.pack('>I', n & xffffffff) + s
        n >>= 32
    # strip off leading zeros, FFs
    for i in enumerate(s):
        if (n == 0) and (i[1] != deflate_zero):
            break
        if (n == -1) and (i[1] != deflate_ff):
            break
    else:
        # degenerate case, n was either 0 or -1
        i = (0,)
        if n == 0:
            s = zero_byte
        else:
            s = max_byte
    s = s[i[0]:]
    if add_sign_padding:
        if (n == 0) and (byte_ord(s[0]) >= 0x80):
            s = zero_byte + s
        if (n == -1) and (byte_ord(s[0]) < 0x80):
            s = max_byte + s
    return s


def format_binary(data, prefix=''):
    x = 0
    out = []
    while len(data) > x + 16:
        out.append(format_binary_line(data[x:x+16]))
        x += 16
    if x < len(data):
        out.append(format_binary_line(data[x:]))
    return [prefix + x for x in out]


def format_binary_line(data):
    left = ' '.join(['%02X' % byte_ord(c) for c in data])
    right = ''.join([('.%c..' % c)[(byte_ord(c)+63)//95] for c in data])
    return '%-50s %s' % (left, right)


def hexify(s):
    return hexlify(s).upper()


def unhexify(s):
    return unhexlify(s)


def safe_string(s):
    out = ''
    for c in s:
        if (byte_ord(c) >= 32) and (byte_ord(c) <= 127):
            out += c
        else:
            out += '%%%02X' % byte_ord(c)
    return out


def bit_length(n):
    try:
        return n.bitlength()
    except AttributeError:
        norm = deflate_long(n, False)
        hbyte = byte_ord(norm[0])
        if hbyte == 0:
            return 1
        bitlen = len(norm) * 8
        while not (hbyte & 0x80):
            hbyte <<= 1
            bitlen -= 1
        return bitlen


def tb_strings():
    return ''.join(traceback.format_exception(*sys.exc_info())).split('\n')


def generate_key_bytes(hash_alg, salt, key, nbytes):
    """
    Given a password, passphrase, or other human-source key, scramble it
    through a secure hash into some keyworthy bytes.  This specific algorithm
    is used for encrypting/decrypting private key files.

    :param function hash_alg: A function which creates a new hash object, such
        as ``hashlib.sha256``.
    :param salt: data to salt the hash with.
    :type salt: byte string
    :param str key: human-entered password or passphrase.
    :param int nbytes: number of bytes to generate.
    :return: Key data `str`
    """
    keydata = bytes()
    digest = bytes()
    if len(salt) > 8:
        salt = salt[:8]
    while nbytes > 0:
        hash_obj = hash_alg()
        if len(digest) > 0:
            hash_obj.update(digest)
        hash_obj.update(b(key))
        hash_obj.update(salt)
        digest = hash_obj.digest()
        size = min(nbytes, len(digest))
        keydata += digest[:size]
        nbytes -= size
    return keydata


def load_host_keys(filename):
    """
    Read a file of known SSH host keys, in the format used by openssh, and
    return a compound dict of ``hostname -> keytype ->`` `PKey
    <paramiko.pkey.PKey>`. The hostname may be an IP address or DNS name.  The
    keytype will be either ``"ssh-rsa"`` or ``"ssh-dss"``.

    This type of file unfortunately doesn't exist on Windows, but on posix,
    it will usually be stored in ``os.path.expanduser("~/.ssh/known_hosts")``.

    Since 1.5.3, this is just a wrapper around `.HostKeys`.

    :param str filename: name of the file to read host keys from
    :return:
        nested dict of `.PKey` objects, indexed by hostname and then keytype
    """
    from paramiko.hostkeys import HostKeys
    return HostKeys(filename)


def parse_ssh_config(file_obj):
    """
    Provided only as a backward-compatible wrapper around `.SSHConfig`.
    """
    config = SSHConfig()
    config.parse(file_obj)
    return config


def lookup_ssh_host_config(hostname, config):
    """
    Provided only as a backward-compatible wrapper around `.SSHConfig`.
    """
    return config.lookup(hostname)


def mod_inverse(x, m):
    # it's crazy how small Python can make this function.
    u1, u2, u3 = 1, 0, m
    v1, v2, v3 = 0, 1, x

    while v3 > 0:
        q = u3 // v3
        u1, v1 = v1, u1 - v1 * q
        u2, v2 = v2, u2 - v2 * q
        u3, v3 = v3, u3 - v3 * q
    if u2 < 0:
        u2 += m
    return u2

_g_thread_ids = {}
_g_thread_counter = 0
_g_thread_lock = threading.Lock()


def get_thread_id():
    global _g_thread_ids, _g_thread_counter, _g_thread_lock
    tid = id(threading.currentThread())
    try:
        return _g_thread_ids[tid]
    except KeyError:
        _g_thread_lock.acquire()
        try:
            _g_thread_counter += 1
            ret = _g_thread_ids[tid] = _g_thread_counter
        finally:
            _g_thread_lock.release()
        return ret


def log_to_file(filename, level=DEBUG):
    """send paramiko logs to a logfile, if they're not already going somewhere"""
    l = logging.getLogger("paramiko")
    if len(l.handlers) > 0:
        return
    l.setLevel(level)
    f = open(filename, 'w')
    lh = logging.StreamHandler(f)
    lh.setFormatter(logging.Formatter('%(levelname)-.3s [%(asctime)s.%(msecs)03d] thr=%(_threadid)-3d %(name)s: %(message)s',
                                      '%Y%m%d-%H:%M:%S'))
    l.addHandler(lh)


# make only one filter object, so it doesn't get applied more than once
class PFilter (object):
    def filter(self, record):
        record._threadid = get_thread_id()
        return True
_pfilter = PFilter()


def get_logger(name):
    l = logging.getLogger(name)
    l.addFilter(_pfilter)
    return l


def retry_on_signal(function):
    """Retries function until it doesn't raise an EINTR error"""
    while True:
        try:
            return function()
        except EnvironmentError as e:
            if e.errno != errno.EINTR:
                raise


class Counter (object):
    """Stateful counter for CTR mode crypto"""
    def __init__(self, nbits, initial_value=long(1), overflow=long(0)):
        self.blocksize = nbits / 8
        self.overflow = overflow
        # start with value - 1 so we don't have to store intermediate values when counting
        # could the iv be 0?
        if initial_value == 0:
            self.value = array.array('c', max_byte * self.blocksize)
        else:
            x = deflate_long(initial_value - 1, add_sign_padding=False)
            self.value = array.array('c', zero_byte * (self.blocksize - len(x)) + x)

    def __call__(self):
        """Increament the counter and return the new value"""
        i = self.blocksize - 1
        while i > -1:
            c = self.value[i] = byte_chr((byte_ord(self.value[i]) + 1) % 256)
            if c != zero_byte:
                return self.value.tostring()
            i -= 1
        # counter reset
        x = deflate_long(self.overflow, add_sign_padding=False)
        self.value = array.array('c', zero_byte * (self.blocksize - len(x)) + x)
        return self.value.tostring()

    def new(cls, nbits, initial_value=long(1), overflow=long(0)):
        return cls(nbits, initial_value=initial_value, overflow=overflow)
    new = classmethod(new)


def constant_time_bytes_eq(a, b):
    if len(a) != len(b):
        return False
    res = 0
    # noinspection PyUnresolvedReferences
    for i in (xrange if PY2 else range)(len(a)):
        res |= byte_ord(a[i]) ^ byte_ord(b[i])
    return res == 0


class ClosingContextManager(object):
    def __enter__(self):
        return self

    def __exit__(self, type, value, traceback):
        self.close()


def clamp_value(minimum, val, maximum):
    return max(minimum, min(val, maximum))