freenet.crypt

Class KeyGenUtils

java.lang.Object

freenet.crypt.KeyGenUtils

public final class KeyGenUtils
extends java.lang.Object

KeyGenUtils offers a set of methods to easily generate Keys and KeyPairs for specific algorithms as well as for generating IVs and nonces. It will also take keys stored in byte arrays and put them in SecretKey or KeyPair instances.

Constructor Summary

Constructors

Constructor and Description
KeyGenUtils()

Method Summary

Modifier and Type	Method and Description
static javax.crypto.spec.IvParameterSpec	deriveIvParameterSpec(javax.crypto.SecretKey kdfKey, java.lang.Class<?> c, java.lang.String kdfString, KeyType ivType) Derives a IvParameterSpec of the specified type from the given key using the provided class name and kdfString
static javax.crypto.SecretKey	deriveSecretKey(javax.crypto.SecretKey kdfKey, java.lang.Class<?> c, java.lang.String kdfString, KeyType type) Derives a SecretKey of the specified type from the given key using the provided class name and kdfString
static javax.crypto.spec.IvParameterSpec	genIV(int length) Generates a random iv of a specified length
static java.security.KeyPair	genKeyPair(KeyPairType type) Generates a public/private key pair formatted for the algorithm specified and stores the keys in a KeyPair.
static java.nio.ByteBuffer	genNonce(int length) Generates a random nonce of a specified length
static javax.crypto.SecretKey	genSecretKey(KeyType type) Generates a secret key for the specified symmetric algorithm
static javax.crypto.spec.IvParameterSpec	getIvParameterSpec(byte[] iv, int offset, int length) Converts an iv in a specified portion of a byte[] and places it in a IvParameterSpec.
static javax.crypto.spec.IvParameterSpec	getIvParameterSpec(java.nio.ByteBuffer iv) Converts an iv in a ByteBuffer and places it in a IvParameterSpec.
static java.security.KeyPair	getKeyPair(KeyPairType type, byte[] pub, byte[] pri) Converts the specified keys for a specified algorithm to PrivateKey and PublicKey respectively.
static java.security.KeyPair	getKeyPair(KeyPairType type, java.nio.ByteBuffer pub, java.nio.ByteBuffer pri) Converts the specified keys for a specified algorithm to PrivateKey and PublicKey respectively.
static java.security.KeyPair	getKeyPair(java.security.PublicKey pubK, java.security.PrivateKey privK) Takes the PublicKey and PrivateKey and stores them in a KeyPair
static java.security.PublicKey	getPublicKey(KeyPairType type, byte[] pub) Converts a specified key for a specified algorithm to a PublicKey.
static java.security.PublicKey	getPublicKey(KeyPairType type, java.nio.ByteBuffer pub) Converts a specified key for a specified algorithm to a PublicKey.
static java.security.KeyPair	getPublicKeyPair(KeyPairType type, byte[] pub) Converts a specified key for a specified algorithm to a PublicKey which is then stored in a KeyPair.
static java.security.KeyPair	getPublicKeyPair(KeyPairType type, java.nio.ByteBuffer pub) Converts a specified key for a specified algorithm to a PublicKey which is then stored in a KeyPair.
static javax.crypto.SecretKey	getSecretKey(KeyType type, byte[] key) Converts the specified key into a SecretKey for the specified algorithm.
static javax.crypto.SecretKey	getSecretKey(KeyType type, java.nio.ByteBuffer key) Converts the specified key into a SecretKey for the specified algorithm

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyGenUtils

public KeyGenUtils()

Method Detail

genKeyPair

public static java.security.KeyPair genKeyPair(KeyPairType type)

Generates a public/private key pair formatted for the algorithm specified and stores the keys in a KeyPair. Can not handle DSA keys.

Parameters:

type - The algorithm format that the key pair should be generated for.

Returns:

Returns the generated key pair

getPublicKey

public static java.security.PublicKey getPublicKey(KeyPairType type,
                                                   byte[] pub)

Converts a specified key for a specified algorithm to a PublicKey. Can not handle DSA keys.

Parameters:

type - The type of key being passed in

pub - Public key as byte[]

Returns:

Public key as PublicKey

getPublicKey

public static java.security.PublicKey getPublicKey(KeyPairType type,
                                                   java.nio.ByteBuffer pub)

Converts a specified key for a specified algorithm to a PublicKey. Can not handle DSA keys.

Parameters:

type - The type of key being passed in

pub - Public key as ByteBuffer

Returns:

Public key as PublicKey

getPublicKeyPair

public static java.security.KeyPair getPublicKeyPair(KeyPairType type,
                                                     byte[] pub)

Converts a specified key for a specified algorithm to a PublicKey which is then stored in a KeyPair. The private key of the KeyPair is null. Can not handle DSA keys.

Parameters:

type - The type of key being passed in

pub - Public key as byte[]

Returns:

Public key as KeyPair with a null private key

getPublicKeyPair

public static java.security.KeyPair getPublicKeyPair(KeyPairType type,
                                                     java.nio.ByteBuffer pub)

Converts a specified key for a specified algorithm to a PublicKey which is then stored in a KeyPair. The private key of the KeyPair is null. Can not handle DSA keys.

Parameters:

type - The type of key being passed in

pub - Public key as ByteBuffer

Returns:

Public key as KeyPair with a null private key

getKeyPair

public static java.security.KeyPair getKeyPair(KeyPairType type,
                                               byte[] pub,
                                               byte[] pri)

Converts the specified keys for a specified algorithm to PrivateKey and PublicKey respectively. These are then placed in a KeyPair. Can not handle DSA keys.

Parameters:

type - The type of key being passed in

pub - Public key as byte[]

pri - Private key as byte[]

Returns:

The public key and private key in a KeyPair

getKeyPair

public static java.security.KeyPair getKeyPair(KeyPairType type,
                                               java.nio.ByteBuffer pub,
                                               java.nio.ByteBuffer pri)

Converts the specified keys for a specified algorithm to PrivateKey and PublicKey respectively. These are then placed in a KeyPair. Can not handle DSA keys.

Parameters:

type - The type of key being passed in

pub - Public key as ByteBuffer

pri - Private key as ByteBuffer

Returns:

The public key and private key in a KeyPair

getKeyPair

public static java.security.KeyPair getKeyPair(java.security.PublicKey pubK,
                                               java.security.PrivateKey privK)

Takes the PublicKey and PrivateKey and stores them in a KeyPair

Parameters:

pubK - Public key as PublicKey

privK - Private key as PrivateKey

Returns:

The public key and private key in a KeyPair

genSecretKey

public static javax.crypto.SecretKey genSecretKey(KeyType type)

Generates a secret key for the specified symmetric algorithm

Parameters:

type - Type of key to generate

Returns:

Generated key

getSecretKey

public static javax.crypto.SecretKey getSecretKey(KeyType type,
                                                  byte[] key)

Converts the specified key into a SecretKey for the specified algorithm. Checks the length of the key to make sure it is correct. HMAC does not have a set key length, so any key is acceptable when using a key of this type.

Parameters:

key - The byte[] of the key

type - Type of key

Returns:

The key as a SecretKey

getSecretKey

public static javax.crypto.SecretKey getSecretKey(KeyType type,
                                                  java.nio.ByteBuffer key)

Converts the specified key into a SecretKey for the specified algorithm

Parameters:

key - The ByteBuffer of the key

type - Type of key

Returns:

The key as a SecretKey

genNonce

public static java.nio.ByteBuffer genNonce(int length)

Generates a random nonce of a specified length

Parameters:

length - How long the nonce should be

Returns:

The randomly generated nonce

genIV

public static javax.crypto.spec.IvParameterSpec genIV(int length)

Generates a random iv of a specified length

Parameters:

length - How long the iv should be in bytes

Returns:

The randomly generated iv

getIvParameterSpec

public static javax.crypto.spec.IvParameterSpec getIvParameterSpec(byte[] iv,
                                                                   int offset,
                                                                   int length)

Converts an iv in a specified portion of a byte[] and places it in a IvParameterSpec.

Parameters:

iv - The byte[] containing the iv

offset - Where the iv begins

length - How long the iv is

Returns:

Returns an IvParameterSpec containing the iv.

getIvParameterSpec

public static javax.crypto.spec.IvParameterSpec getIvParameterSpec(java.nio.ByteBuffer iv)

Converts an iv in a ByteBuffer and places it in a IvParameterSpec.

Parameters:

iv - The ByteBuffer containing the iv

Returns:

Returns an IvParameterSpec containing the iv.

deriveSecretKey

public static javax.crypto.SecretKey deriveSecretKey(javax.crypto.SecretKey kdfKey,
                                                     java.lang.Class<?> c,
                                                     java.lang.String kdfString,
                                                     KeyType type)
                                              throws java.security.InvalidKeyException

Derives a SecretKey of the specified type from the given key using the provided class name and kdfString

Parameters:

kdfKey - The key to derive from

c - Class name to use in derivation

kdfString - String to use in derivation

type - The type of key to derive

Returns:

The derived key as a SecretKey

Throws:

java.security.InvalidKeyException

deriveIvParameterSpec

public static javax.crypto.spec.IvParameterSpec deriveIvParameterSpec(javax.crypto.SecretKey kdfKey,
                                                                      java.lang.Class<?> c,
                                                                      java.lang.String kdfString,
                                                                      KeyType ivType)
                                                               throws java.security.InvalidKeyException

Derives a IvParameterSpec of the specified type from the given key using the provided class name and kdfString

Parameters:

kdfKey - The key to derive from

c - Class name to use in derivation

kdfString - String to use in derivation

ivType - The type of IV to derive

Returns:

The derived IV as an IvParameterSpec

Throws:

java.security.InvalidKeyException