3 # Copyright 2011 Peter Palfrader
5 # Permission is hereby granted, free of charge, to any person obtaining
6 # a copy of this software and associated documentation files (the
7 # "Software"), to deal in the Software without restriction, including
8 # without limitation the rights to use, copy, modify, merge, publish,
9 # distribute, sublicense, and/or sell copies of the Software, and to
10 # permit persons to whom the Software is furnished to do so, subject to
11 # the following conditions:
13 # The above copyright notice and this permission notice shall be
14 # included in all copies or substantial portions of the Software.
16 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
29 AVAIL = '/proc/sys/kernel/random/entropy_avail'
31 parser = optparse.OptionParser()
32 parser.add_option("-r", "--retries", dest="retries", metavar="NUM",
33 type="int", default=10,
34 help="Max number of retries [10].")
35 parser.add_option("-s", "--sleep", dest="sleep", metavar="MSECS",
36 type="int", default=250,
37 help="Amount of time to wait between reads [250msec].")
38 parser.add_option("-w", "--watermark", dest="watermark", metavar="BYTES",
39 type="int", default=800,
40 help="Minimum number of expected bytes in the entropy pool [800].")
41 (options, args) = parser.parse_args()
47 if not os.path.exists(AVAIL):
48 print "File %s does not exist."%(AVAIL)
53 while tries <= options.retries:
54 f = open('/proc/sys/kernel/random/entropy_avail')
55 avail = f.readline().rstrip()
57 print "Could not read anything from %s"%(AVAIL)
62 print "Did not read a number from %s, got '%s' instead"%(AVAIL, avail)
65 if avail >= options.watermark:
67 print "OK: %d bytes in the pool after %d attempts."%(avail, tries)
69 print "OK: %d bytes in the pool."%(avail)
73 time.sleep(1.0 * options.sleep / 1000)
76 print "WARNING: Too little entropy in the pool (min: %d, max: %d in %d reads)"%(min(values), max(values), tries-1)
81 # vim:set shiftwidth=4: