net.i2p.crypto

Class KeyGenerator

java.lang.Object

net.i2p.crypto.KeyGenerator

public final class KeyGenerator
extends Object

Comprehensive key generation facility for I2P cryptographic operations. This class provides methods to generate various types of cryptographic keys used throughout the I2P network, including:

• Asymmetric key pairs (ElGamal, DSA, ECDSA, EdDSA, RSA)
• Symmetric session keys (AES)
• Key derivation and conversion utilities

Supports both legacy algorithms (DSA, ElGamal) and modern cryptographic schemes (EdDSA, ECDSA) with configurable parameters for security and performance optimization.

Constructor Summary

Constructors

Constructor and Description
KeyGenerator(I2PAppContext context)

Method Summary

Modifier and Type	Method and Description
Object[]	generatePKIKeypair() ElGamal only.
SimpleDataStructure[]	generatePKIKeys() ElGamal only.
KeyPair	generatePKIKeys(EncType type) Supports EncTypes
SessionKey	generateSessionKey() Generate a private 256 bit session key
SessionKey	generateSessionKey(byte[] salt, byte[] passphrase) PBE the passphrase with the salt.
Object[]	generateSigningKeypair() Generate a pair of DSA keys, where index 0 is a SigningPublicKey, and index 1 is a SigningPrivateKey.
SimpleDataStructure[]	generateSigningKeys() DSA-SHA1 only.
SimpleDataStructure[]	generateSigningKeys(SigType type) Generic signature type, supports DSA, RSA, ECDSA, EdDSA
int	getElGamalExponentSize() Get the size of the ElGamal exponent in bits.
static KeyGenerator	getInstance()
static PublicKey	getPublicKey(PrivateKey priv) Convert a PrivateKey to its corresponding PublicKey.
static SigningPublicKey	getSigningPublicKey(SigningPrivateKey priv) Convert a SigningPrivateKey to a SigningPublicKey.
static void	main(String[] args) Usage: KeyGenerator [sigtype...]
boolean	useLongElGamalExponent() Whether to use a long (2048-bit) ElGamal exponent.

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyGenerator

public KeyGenerator(I2PAppContext context)

Method Detail

generatePKIKeypair

public Object[] generatePKIKeypair()

ElGamal only. Generate a pair of keys, where index 0 is a PublicKey, and index 1 is a PrivateKey

Returns:

pair of keys

generatePKIKeys

public SimpleDataStructure[] generatePKIKeys()

ElGamal only. Same as generatePKIKeypair() but different return type.

generatePKIKeys

public KeyPair generatePKIKeys(EncType type)

Supports EncTypes

generateSessionKey

public SessionKey generateSessionKey()

Generate a private 256 bit session key

Returns:

session key

generateSessionKey

public SessionKey generateSessionKey(byte[] salt,
                                     byte[] passphrase)

PBE the passphrase with the salt. Warning - SLOW

generateSigningKeypair

public Object[] generateSigningKeypair()

Generate a pair of DSA keys, where index 0 is a SigningPublicKey, and index 1 is a SigningPrivateKey. DSA-SHA1 only.

Returns:

pair of keys

generateSigningKeys

public SimpleDataStructure[] generateSigningKeys()

DSA-SHA1 only. Same as above but different return type

generateSigningKeys

public SimpleDataStructure[] generateSigningKeys(SigType type)
                                          throws GeneralSecurityException

Generic signature type, supports DSA, RSA, ECDSA, EdDSA

Throws:

GeneralSecurityException

getElGamalExponentSize

public int getElGamalExponentSize()

Get the size of the ElGamal exponent in bits.

getInstance

public static KeyGenerator getInstance()

getPublicKey

public static PublicKey getPublicKey(PrivateKey priv)

Convert a PrivateKey to its corresponding PublicKey. As of 0.9.38, supports EncTypes

Parameters:

priv - PrivateKey object

Returns:

the corresponding PublicKey object

Throws:

IllegalArgumentException - on bad key

getSigningPublicKey

public static SigningPublicKey getSigningPublicKey(SigningPrivateKey priv)

Convert a SigningPrivateKey to a SigningPublicKey. As of 0.9.16, supports all key types.

Parameters:

priv - a SigningPrivateKey object

Returns:

a SigningPublicKey object

Throws:

IllegalArgumentException - on bad key or unknown type

main

public static void main(String[] args)

Usage: KeyGenerator [sigtype...]

useLongElGamalExponent

public boolean useLongElGamalExponent()

Whether to use a long (2048-bit) ElGamal exponent.