This file is indexed.

/usr/bin/gpgparticipants-prefill is in signing-party 1.1.5-1.

This file is owned by root:root, with mode 0o755.

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
#!/usr/bin/python
"""Fill in the first digits of the hash in a form created by gpgparticipants."""

__version__ = "1.0"

__author__ = "Stefan Huber"
__email__ = "shuber@sthu.org"
__copyright__ = "Copyright 2013, Stefan Huber"

__license__ = "MIT"

# 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 sys
import hashlib
import getopt


def insertspaces(s):
    """Inserts a space after every 4-th character, and three spaces after every
    8-th character of string s."""

    def inpacks(s, n):
        while len(s) > 0:
            yield s[0:n]
            s = s[n:]

    out = "   ".join([ " ".join(inpacks(octp, 4)) for octp in inpacks(s, 8)])
    return out


def range_hex(length):
    """Give all hex-strings from 00...0 until ff...f of given length."""

    if length == 0:
        yield ""

    elif length == 1:
        for c in "0123456789abcdef":
            yield c
    elif length > 1:
        for prefix in range_hex(length-1):
            for postfix in range_hex(1):
                yield prefix + postfix


def usage():
    """Print --help text"""

    print("""Usage:
  {0} <emptylist> <filledlist>
  {0} --help
  {0} -h

Takes a file produced by gpgparticipants as <emptylist> and trys to fill in
some digits into the SHA256 field such that the resulting list actually has
a SHA256 checksum that starts with those digits. Whenever a match is found a
file with the digits filled in is written to `<filledlist>.DIGITS`.

OPTIONS:

  --fastforward        If a match is found of given length and --fastforward
                       is given then the program immediately jumps to the next
                       length.
  --min-length NUM     Start search with given length.

""".format(sys.argv[0]))


if __name__ == "__main__":

    fastforward = False
    minlength = 1

    optlist, args = getopt.getopt(sys.argv[1:], 'h', ['fastforward', 'min-length=', 'help'])
    for o, a in optlist:

        if o in ("-h", "--help"):
            usage()
            exit(0)

        if o in ("--fastforward"):
            fastforward = True

        if o in ("--min-length"):
            minlength = int(a)

    if len(args) < 2:
        print >>sys.stderr, "You need to give two filenames."""
        exit(1)

    emptyfile = open(args[0]).read()

    idx = emptyfile.find("SHA256 Checksum:")
    idx = emptyfile.find("_", idx)

    for l in range(minlength, 32):
        print "Looking at length", l

        for h in range_hex(l):

            H = insertspaces(h.upper())
            filledfile = emptyfile[:idx] + H + emptyfile[idx+len(H):]
            actual = hashlib.sha256(filledfile).hexdigest()

            if actual[:len(h)] == h:
                print "Found: ", H
                open(args[1] + "." + h, "w").write(filledfile)

                if fastforward:
                    break