org.spongycastle.crypto.kems

Class RSAKeyEncapsulation

java.lang.Object

org.spongycastle.crypto.kems.RSAKeyEncapsulation

All Implemented Interfaces:

KeyEncapsulation

public class RSAKeyEncapsulation
extends java.lang.Object
implements KeyEncapsulation

The RSA Key Encapsulation Mechanism (RSA-KEM) from ISO 18033-2.

Constructor Summary

Constructors

Constructor and Description
RSAKeyEncapsulation(DerivationFunction kdf, java.security.SecureRandom rnd) Set up the RSA-KEM.

Method Summary

Modifier and Type	Method and Description
CipherParameters	decrypt(byte[] in, int keyLen) Decrypt an encapsulated session key.
CipherParameters	decrypt(byte[] in, int inOff, int inLen, int keyLen) Decrypt an encapsulated session key.
CipherParameters	encrypt(byte[] out, int keyLen) Generate and encapsulate a random session key.
CipherParameters	encrypt(byte[] out, int outOff, int keyLen) Generate and encapsulate a random session key.
protected KeyParameter	generateKey(java.math.BigInteger n, java.math.BigInteger r, int keyLen)
void	init(CipherParameters key) Initialise the RSA-KEM.

Methods inherited from class java.lang.Object

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

Constructor Detail

RSAKeyEncapsulation

public RSAKeyEncapsulation(DerivationFunction kdf,
                           java.security.SecureRandom rnd)

Set up the RSA-KEM.

Parameters:

kdf - the key derivation function to be used.

rnd - the random source for the session key.

Method Detail

init

public void init(CipherParameters key)
          throws java.lang.IllegalArgumentException

Initialise the RSA-KEM.

Specified by:

init in interface KeyEncapsulation

Parameters:

key - the recipient's public (for encryption) or private (for decryption) key.

Throws:

java.lang.IllegalArgumentException

encrypt

public CipherParameters encrypt(byte[] out,
                                int outOff,
                                int keyLen)
                         throws java.lang.IllegalArgumentException

Generate and encapsulate a random session key.

Specified by:

encrypt in interface KeyEncapsulation

Parameters:

out - the output buffer for the encapsulated key.

outOff - the offset for the output buffer.

keyLen - the length of the random session key.

Returns:

the random session key.

Throws:

java.lang.IllegalArgumentException

encrypt

public CipherParameters encrypt(byte[] out,
                                int keyLen)

Generate and encapsulate a random session key.

Parameters:

out - the output buffer for the encapsulated key.

keyLen - the length of the random session key.

Returns:

the random session key.

decrypt

public CipherParameters decrypt(byte[] in,
                                int inOff,
                                int inLen,
                                int keyLen)
                         throws java.lang.IllegalArgumentException

Decrypt an encapsulated session key.

Specified by:

decrypt in interface KeyEncapsulation

Parameters:

in - the input buffer for the encapsulated key.

inOff - the offset for the input buffer.

inLen - the length of the encapsulated key.

keyLen - the length of the session key.

Returns:

the session key.

Throws:

java.lang.IllegalArgumentException

decrypt

public CipherParameters decrypt(byte[] in,
                                int keyLen)

Decrypt an encapsulated session key.

Parameters:

in - the input buffer for the encapsulated key.

keyLen - the length of the session key.

Returns:

the session key.

generateKey

protected KeyParameter generateKey(java.math.BigInteger n,
                                   java.math.BigInteger r,
                                   int keyLen)