1

     2

     3

import os

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from binascii import b2a_base64

     5

try:

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    from runtime.spawn_subprocess import call

     7

except ImportError:

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    from subprocess import call

     9

    10

restart_stunnel_cmdline = ["/etc/init.d/S50stunnel", "restart"]

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_PSKpath = None

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    14

    15

def restartStunnel():

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    """

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    Restart stunnel service using SysV init stript

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    to apply new generated credentials

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    """

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    try:

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        call(restart_stunnel_cmdline)

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    except OSError:

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        print(_("Couldn't restart stunnel service"))

    24

    25

    26

def PSKgen(ID, PSKpath):

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    28

    # secret string length is 256

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    # b2a_base64 output len is 4/3 input len

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    secret = os.urandom(192)  # int(256/1.3333)

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    secretstring = b2a_base64(secret)

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    PSKstring = ID+":"+secretstring

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    with open(PSKpath, 'w') as f:

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        f.write(PSKstring)

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    restartStunnel()

    37

    38

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def ensurePSK(ID, PSKpath):

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    global _PSKpath

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    _PSKpath = PSKpath

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    # check if already there

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    if not os.path.exists(PSKpath):

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        # create if needed

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        PSKgen(ID, PSKpath)

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    47

    48

def getPSKID(errorlog):

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    if _PSKpath is not None:

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        if not os.path.exists(_PSKpath):

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            errorlog(

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                'Error: Pre-Shared-Key Secret in %s is missing!\n' % _PSKpath)

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            return ("","")

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        ID, _sep, PSK = open(_PSKpath).read().partition(':')

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        PSK = PSK.rstrip('\n\r')

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        return (ID, PSK)

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    return ("","")