SecureRandomSpi (Java SE 9 & JDK 9 ) (original) (raw)

java.lang.Object
- java.security.SecureRandomSpi
All Implemented Interfaces:
[Serializable](../../java/io/Serializable.html "interface in java.io")

public abstract class SecureRandomSpi
extends Object
implements Serializable
This class defines the Service Provider Interface (SPI) for the SecureRandom class.
All the abstract methods in this class must be implemented by each service provider who wishes to supply the implementation of a cryptographically strong pseudo-random number generator.
Implementation Requirements:
If the SecureRandomSpi(SecureRandomParameters) constructor is overridden in an implementation, it will always be called whenever a SecureRandom is instantiated. Precisely, if an object is instantiated with one of SecureRandom's getInstance methods_without_ a SecureRandomParameters parameter, the constructor will be called with a null argument and the implementation is responsible for creating its ownSecureRandomParameters parameter for use whenengineGetParameters() is called. If an object is instantiated with one of SecureRandom's getInstance methods with a SecureRandomParameters argument, the constructor will be called with that argument. TheengineGetParameters() method must not return null.
Otherwise, if the SecureRandomSpi(SecureRandomParameters) constructor is not overridden in an implementation, theSecureRandomSpi() constructor must be overridden and it will be called if an object is instantiated with one of SecureRandom'sgetInstance methods without aSecureRandomParameters argument. Calling one ofSecureRandom's getInstance methods with a SecureRandomParameters argument will never return an instance of this implementation. TheengineGetParameters() method must return null.
See SecureRandom for additional details on thread safety. By default, a SecureRandomSpi implementation is considered to be not safe for use by multiple concurrent threads and SecureRandom will synchronize access to each of the applicable engine methods (see SecureRandom for the list of methods). However, if aSecureRandomSpi implementation is thread-safe, the service provider attribute "ThreadSafe" should be set to "true" during its registration, as follows:

put("SecureRandom.AlgName ThreadSafe", "true");
or
putService(new Service(this, "SecureRandom", "AlgName", className,
null, Map.of("ThreadSafe", "true")));
SecureRandom will call the applicable engine methods without any synchronization.
Since:
1.2
See Also:
Serialized Form

Constructor Summary

Constructors

Modifier	Constructor	Description
	SecureRandomSpi()	Constructor without a parameter.
protected	SecureRandomSpi(SecureRandomParameters params)	Constructor with a parameter.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods

Modifier and Type	Method	Description
protected abstract byte[]	engineGenerateSeed(int numBytes)	Returns the given number of seed bytes.
protected SecureRandomParameters	engineGetParameters()	Returns the effective SecureRandomParameters for thisSecureRandom instance.
protected abstract void	engineNextBytes(byte[] bytes)	Generates a user-specified number of random bytes.
protected void	engineNextBytes(byte[] bytes,SecureRandomParameters params)	Generates a user-specified number of random bytes with additional parameters.
protected void	engineReseed(SecureRandomParameters params)	Reseeds this random object with entropy input read from its entropy source with additional parameters.
protected abstract void	engineSetSeed(byte[] seed)	Reseeds this random object with the given seed.
String	toString()	Returns a Human-readable string representation of thisSecureRandom.

   * ### Methods inherited from class java.lang.[Object](../../java/lang/Object.html "class in java.lang")  
   `[clone](../../java/lang/Object.html#clone--), [equals](../../java/lang/Object.html#equals-java.lang.Object-), [finalize](../../java/lang/Object.html#finalize--), [getClass](../../java/lang/Object.html#getClass--), [hashCode](../../java/lang/Object.html#hashCode--), [notify](../../java/lang/Object.html#notify--), [notifyAll](../../java/lang/Object.html#notifyAll--), [wait](../../java/lang/Object.html#wait--), [wait](../../java/lang/Object.html#wait-long-), [wait](../../java/lang/Object.html#wait-long-int-)`

Constructor Detail

 * #### SecureRandomSpi  
 public SecureRandomSpi()  
 Constructor without a parameter.  
 * #### SecureRandomSpi  
 protected SecureRandomSpi([SecureRandomParameters](../../java/security/SecureRandomParameters.html "interface in java.security") params)  
 Constructor with a parameter.  
 Parameters:  
 `params` \- the [SecureRandomParameters](../../java/security/SecureRandomParameters.html "interface in java.security") object. This argument can be `null`.  
 Throws:  
 `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if `params` is unrecognizable or unsupported by this `SecureRandom`  
 Since:  
 9

Method Detail

* #### engineSetSeed  
protected abstract void engineSetSeed(byte[] seed)  
Reseeds this random object with the given seed. The seed supplements, rather than replaces, the existing seed. Thus, repeated calls are guaranteed never to reduce randomness.  
Parameters:  
`seed` \- the seed.  
* #### engineNextBytes  
protected abstract void engineNextBytes(byte[] bytes)  
Generates a user-specified number of random bytes.  
 Some random number generators can only generate a limited amount of random bytes per invocation. If the size of `bytes` is greater than this limit, the implementation should invoke its generation process multiple times to completely fill the buffer before returning from this method.  
Parameters:  
`bytes` \- the array to be filled in with random bytes.  
* #### engineNextBytes  
protected void engineNextBytes(byte[] bytes,  
                               [SecureRandomParameters](../../java/security/SecureRandomParameters.html "interface in java.security") params)  
Generates a user-specified number of random bytes with additional parameters.  
 Some random number generators can only generate a limited amount of random bytes per invocation. If the size of `bytes` is greater than this limit, the implementation should invoke its generation process multiple times to completely fill the buffer before returning from this method.  
Implementation Requirements:  
The default implementation throws an [UnsupportedOperationException](../../java/lang/UnsupportedOperationException.html "class in java.lang").  
Parameters:  
`bytes` \- the array to be filled in with random bytes  
`params` \- additional parameters  
Throws:  
`[UnsupportedOperationException](../../java/lang/UnsupportedOperationException.html "class in java.lang")` \- if the implementation has not overridden this method  
`[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if `params` is `null`, illegal or unsupported by this `SecureRandom`  
Since:  
9  
* #### engineGenerateSeed  
protected abstract byte[] engineGenerateSeed(int numBytes)  
Returns the given number of seed bytes. This call may be used to seed other random number generators.  
Parameters:  
`numBytes` \- the number of seed bytes to generate.  
Returns:  
the seed bytes.  
* #### engineReseed  
protected void engineReseed([SecureRandomParameters](../../java/security/SecureRandomParameters.html "interface in java.security") params)  
Reseeds this random object with entropy input read from its entropy source with additional parameters.  
 If this method is called by [SecureRandom.reseed()](../../java/security/SecureRandom.html#reseed--),`params` will be `null`.  
 Do not override this method if the implementation does not support reseeding.  
Implementation Requirements:  
The default implementation throws an [UnsupportedOperationException](../../java/lang/UnsupportedOperationException.html "class in java.lang").  
Parameters:  
`params` \- extra parameters, can be `null`.  
Throws:  
`[UnsupportedOperationException](../../java/lang/UnsupportedOperationException.html "class in java.lang")` \- if the implementation has not overridden this method  
`[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if `params` is illegal or unsupported by this `SecureRandom`  
Since:  
9  
* #### engineGetParameters  
protected [SecureRandomParameters](../../java/security/SecureRandomParameters.html "interface in java.security") engineGetParameters()  
Implementation Requirements:  
The default implementation returns `null`.  
Returns:  
the effective [SecureRandomParameters](../../java/security/SecureRandomParameters.html "interface in java.security") parameters, or `null` if no parameters were used.  
Since:  
9  
* #### toString  
public [String](../../java/lang/String.html "class in java.lang") toString()  
Returns a Human-readable string representation of this`SecureRandom`.  
Overrides:  
`[toString](../../java/lang/Object.html#toString--)` in class `[Object](../../java/lang/Object.html "class in java.lang")`  
Returns:  
the string representation

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SecureRandomSpi (Java SE 9 & JDK 9 ) (original) (raw)

Constructor Summary

Method Summary

Constructor Detail

Method Detail