Class CSPRNG

public static final String FILE_SOURCES

Property name for the list of files to read for random values. The mapped value is a list with the following values:

1. A Double, indicating the suggested quality of this source. This value must be between 0 and 100.
2. An Integer, indicating the number of bytes to skip in the file before reading bytes. This can be any nonnegative value.
3. An Integer, indicating the number of bytes to read.
4. A String, indicating the path to the file.

See Also:

SimpleList

public static final String OTHER_SOURCES

Property name for a list of other sources of entropy. The mapped value must be a list of EntropySource objects.

public static final String PROGRAM_SOURCES

Property name for the list of programs to execute, and use the output as new random bytes. The mapped property is formatted similarly an in FILE_SOURCES and URL_SOURCES, except the fourth member is a String of the program to execute.

public static final String URL_SOURCES

Property name for the list of URLs to poll for random values. The mapped value is a list formatted similarly as in FILE_SOURCES, but the fourth member is a URL.

public void addRandomByte(byte b)

Add a single random byte to the randomness pool. Note that this method will not increment the pool's quality counter (this can only be done via a source provided to the setup method).

Specified by:

addRandomByte in interface IRandom

Overrides:

addRandomByte in interface BasePRNG

Parameters:

b - The byte to add.

public void addRandomBytes(byte[] buf,
                           int off,
                           int len)

Add an array of bytes into the randomness pool. Note that this method will not increment the pool's quality counter (this can only be done via a source provided to the setup method).

Specified by:

addRandomBytes in interface IRandom

Overrides:

addRandomBytes in interface BasePRNG

Parameters:

buf - The byte array.

off - The offset from whence to start reading bytes.

len - The number of bytes to add.

public Object clone()

Specified by:

clone in interface IRandom

Overrides:

clone in interface BasePRNG

public void fillBlock()
            throws LimitReachedException

Overrides:

fillBlock in interface BasePRNG

public static IRandom getSystemInstance()
            throws ClassNotFoundException,
                   MalformedURLException,
                   NumberFormatException

Create and initialize a CSPRNG instance with the "system" parameters; the files, URLs, programs, and EntropySource sources used by the instance are derived from properties set in the system Properties.

All properties are of the from name.N, where name is the name of the source, and N is an integer (staring at 1) that indicates the preference number for that source.

The following vales for name are used here:

FILE_SOURCES

quality ; offset ; count ; path

FILE_SOURCES

URL_SOURCESpath

PROGRAM_SOURCES

OTHER_SOURCESEntropySource

Finally, a boolean property "gnu.crypto.csprng.blocking" can be set to the desired value of BLOCKING.

An example of valid properties would be:

 gnu.crypto.csprng.blocking=true

 gnu.crypto.csprng.file.1=75.0;0;256;/dev/random
 gnu.crypto.csprng.file.2=10.0;0;100;/home/user/file

 gnu.crypto.csprng.url.1=5.0;0;256;http://www.random.org/cgi-bin/randbyte?nbytes=256
 gnu.crypto.csprng.url.2=0;256;256;http://slashdot.org/

 gnu.crypto.csprng.program.1=0.5;0;10;last -n 50
 gnu.crypto.csprng.program.2=0.5;0;10;tcpdump -c 5

 gnu.crypto.csprng.other.1=foo.bar.MyEntropySource
 gnu.crypto.csprng.other.2=com.company.OtherEntropySource
 

public void setup(Map attrib)

Overrides:

setup in interface BasePRNG