iaik.security.rsa

Class RSAKeyPairGenerator

java.lang.Object

java.security.KeyPairGeneratorSpi

java.security.KeyPairGenerator

iaik.security.rsa.RSAKeyPairGenerator

Direct Known Subclasses:

RSAKeyPairGeneratorFIPS, RSAOaepKeyPairGenerator, RSAPssKeyPairGenerator

public class RSAKeyPairGenerator
extends java.security.KeyPairGenerator

The RSAKeyPairGenerator class is used to generate keys for the RSA algorithm according to IEEE P1363.

For creating a RSA key pair, a KeyPairGenerator has to be instantiated, properly initialized and directed to actually generate the keys by calling the generateKeyPair method. If the generator is not initialized by explicitly calling an initialize method, the modulus length per default is set to 2048 bits.

Generating RSA keys using a modulus length of, e.g. 1024 bits, may be done by:

 KeyPairGenerator key_gen = KeyPairGenerator.getIntance("RSA");
 key_gen.initialize(1024, sec_random);
 KeyPair key_pair = key_gen.generateKeyPair();
 

Version:

File Revision 37

See Also:

KeyPairGenerator, KeyPair, RSAPublicKey, RSAPrivateKey, RSAKeyFactory

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	initialized
protected int	keylen
protected java.math.BigInteger	public_exponent
protected java.security.SecureRandom	random

Constructor Summary

Constructors

Constructor and Description
RSAKeyPairGenerator() Default constructor for creating a RSAKeyPairGenerator object.

Method Summary

Methods

Modifier and Type	Method and Description
java.security.KeyPair	generateKeyPair() Actually generates the requested RSA KeyPair.
void	initialize(java.security.spec.AlgorithmParameterSpec params) Initializes this RSAKeyPairGenerator with the given AlgorithmParameterSpec.
void	initialize(java.security.spec.AlgorithmParameterSpec params, java.security.SecureRandom random) Initializes this RSAPssKeyPairGenerator with given AlgorithmParameterSpec and random number generator.
void	initialize(int strength) Initializes the RSAKeyPairGenerator for a certain key length with the default random seed.
void	initialize(int strength, java.math.BigInteger publicExponent, java.security.SecureRandom secureRandom) Initializes the key pair generator using the specified "strength" (desired key length in bits), public exponent, and source of random bits.
void	initialize(int strength, java.security.SecureRandom secureRandom) Initializes the RSAKeyPairGenerator for a certain key length with the given random seed.

Methods inherited from class java.security.KeyPairGenerator

genKeyPair, getAlgorithm, getInstance, getInstance, getInstance, getProvider

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

keylen

protected int keylen

random

protected java.security.SecureRandom random

public_exponent

protected java.math.BigInteger public_exponent

initialized

protected boolean initialized

Constructor Detail

RSAKeyPairGenerator

public RSAKeyPairGenerator()

Default constructor for creating a RSAKeyPairGenerator object.

Method Detail

initialize

public void initialize(int strength)

Initializes the RSAKeyPairGenerator for a certain key length with the default random seed.

Overrides:

initialize in class java.security.KeyPairGenerator

Parameters:

strength - the length of the key in bits.

initialize

public void initialize(int strength,
              java.security.SecureRandom secureRandom)

Initializes the RSAKeyPairGenerator for a certain key length with the given random seed.

Overrides:

initialize in class java.security.KeyPairGenerator

Parameters:

strength - the length of the key in bits.

secureRandom - the random seed

initialize

public void initialize(int strength,
              java.math.BigInteger publicExponent,
              java.security.SecureRandom secureRandom)

Initializes the key pair generator using the specified "strength" (desired key length in bits), public exponent, and source of random bits. Typical values for the public exponent are the Fermat primes F4 and F0 (0x10001 and 0x11) and, less commonly, 17.

When using this initialization method an explicit cast to RSAKeyPairGenerator has to be made:

 RSAKeyPairGenerator keyGen = (RSAKeyPairGenerator)KeyPairGenerator.getInstance("RSA", "IAIK");
 keyGen.initialize(strength, publicExponent, secureRandom);
 ...
 

Parameters:

strength - keyLength the length of the key in bits.

publicExponent - the public exponent

secureRandom - the random seed

initialize

public void initialize(java.security.spec.AlgorithmParameterSpec params)
                throws java.security.InvalidAlgorithmParameterException

Initializes this RSAKeyPairGenerator with the given AlgorithmParameterSpec.

Overrides:

initialize in class java.security.KeyPairGenerator

Parameters:

params - the RSAPssParameterSpec for initializing this generator

Throws:

java.security.InvalidAlgorithmParameterException - if the given parameter specification is not a RSAKeyGenParameterSpec

initialize

public void initialize(java.security.spec.AlgorithmParameterSpec params,
              java.security.SecureRandom random)
                throws java.security.InvalidAlgorithmParameterException

Initializes this RSAPssKeyPairGenerator with given AlgorithmParameterSpec and random number generator.

Overrides:

initialize in class java.security.KeyPairGenerator

Parameters:

params - the RSAKeyGenParameterSpec for initializing this generator

random - the SecureRandom for generating random numbers

Throws:

java.security.InvalidAlgorithmParameterException - if the given parameter specification is not a RSAKeyGenParameterSpec

generateKeyPair

public java.security.KeyPair generateKeyPair()

Actually generates the requested RSA KeyPair.

Overrides:

generateKeyPair in class java.security.KeyPairGenerator

Returns:

the requested KeyPair