Class: RandomGenerator

• Inheritance
• Description
• Related information
• Class protocol
  • adding entropy
  • change & update
  • initialization
  • instance creation
  • queries
• Instance protocol
  • adding entropy
  • basic reading
  • reading
  • writing

Inheritance:

   Object
   |
   +--RandomGenerator

Package:

stx:libbasic2

Category:

Magnitude-Numbers

Version:

rev: 1.8 date: 2010/03/31 10:37:41

user: stefan

file: RandomGenerator.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Author:

Stefan Vogel

Description:

This is a Random number generator, which uses either a OS random number generator,
or a ST/X internal random number generator.



[instance variables:]

[class variables:]
    RandFile        the FileStream we get random numbers from

Related information:

    Random
    HashRandom
    Rc4Stream

Class protocol:

 addEntropy: entropyBytes

 update: something with: aParameter from: changedObject

handle image restarts and flush any device resource handles

 initialize

want to be informed when returning from snapshot

 openRandFile

try to open a random device

 new

return a new random number generator.
Try to get system random numbers from device (e.g. in LINUX).
If no system random nubers are available, fall back to
a cryptographic secure PRNG (part of the extra libcrypt package).
As last resort fallback to the cryptographic insecure linear builtin PRNG

 random

alias for new - protocol compatibility with StreamCiphers

 randPath

path to a file/device that is a source or random numbers

Instance protocol:

 addEntropy: entropyBytes

add some entropy - ignored here, since I am file based

 nextByte

get the next random byte

 nextBytes: cnt

get the next cnt random bytes

 nextInteger

return the next integral random number,
in the range 0 .. 16r3FFFFFFF.

 next

return the next random number in the range 0..1

 nextBetween: start and: stop

return a random number between start and stop.

 nextBoolean

return true or false by random

 nextCharacters: cnt

get the next cnt printable characters.
We answer characters in the ascii range (codepoints 32 - 127)

 nextIntegerBetween: start and: stop

return an integral random number between start and stop

 nextMatchFor: aNumber

generate the next random, return true iff it has the same
value as aNumber. Redefined to avoid endless reading.

 nextPut: something

change the random pool by feeding in something.
Something should be some unpredictable, random event.
Ignored here

 nextPutAll: something

change the random pool by feeding in something.
Something should be some unpredictable, random event.
Ignored here