  
  [1X6 [33X[0;0YReally random sources[133X[101X
  
  [33X[0;0YThis  section describes so called [21Xreal random sources[121X. It is an extension to
  the  library  mechanism  of  random  source  objects  that  uses the devices
  [11X/dev/random[111X  and [11X/dev/urandom[111X available on [11XLinux[111X systems (and maybe on other
  operating  systems) providing random numbers that are impossible to predict.
  The  idea  is  that  such  sources  of  random numbers are useful to produce
  unpredictable secret keys for cryptographic applications.[133X
  
  
  [1X6.1 [33X[0;0YThe functions[133X[101X
  
  [1X6.1-1 RandomSource[101X
  
  [33X[1;0Y[29X[2XRandomSource[102X( [3Xr[103X, [3Xdev[103X ) [32X method[133X
  [6XReturns:[106X  [33X[0;10Ya real random source object or [10Xfail[110X[133X
  
  [33X[0;0YThe  first  argument  [3Xr[103X  must  be  the [5XGAP[105X filter [10XIsRealRandomSource[110X and the
  second  either the string [11Xrandom[111X or the string [11Xurandom[111X. A real random source
  object  is  created  that  draws  its random numbers from the kernel devices
  [11X/dev/random[111X  and  [11X/dev/urandom[111X  respectively.  Whereas  [11X/dev/urandom[111X  always
  provides  random  numbers  of not guaranteed [21Xquality[121X, the device [11X/dev/random[111X
  measures its entropy and produces guaranteed unpredictable numbers. However,
  it  might  block until enough [21Xrandom[121X events (like mouse movements) have been
  accumulated.[133X
  
