com.absio.crypto.key

Class KeyFileHelper

java.lang.Object

com.absio.crypto.key.KeyFileHelper

public class KeyFileHelper
extends Object

This helper class can be used to encrypt KeyRing's and create the KeyFile formatted data or decrypt a KeyRing from the KeyFile formatted data.

Constructor Summary

Constructors

Constructor and Description
KeyFileHelper(MessageDigestAlgorithm passwordHashingAlgorithm) Create a KeyFile helper that WILL hash passwords before they are used to PBKDF2 the KeyRing.

Method Summary

Modifier and Type	Method and Description
KeyRing	decryptKeyRing(byte[] keyFileBytes, String password) This will decrypt the @link KeyRing} from the formatted KeyFile data using the password (if the helper was created with a MessageDigestAlgorithm the password will first be hashed using that algorithm, hex encoded and changed to lowercase).
KeyRing	decryptKeyRingWithRescue(byte[] keyFileBytes, String passphrase) This will decrypt the @link KeyRing} from the formatted KeyFile data.
byte[]	encrypt(KeyRing keyRing, String password, String passphrase) This will PBKDF2 encrypt the KeyRing using the password (if the helper was created with a MessageDigestAlgorithm the password will first be hashed using that algorithm, hex encoded and changed to lowercase).
byte[]	encrypt(KeyRing keyRing, String password, String passphrase, KeyFileSettings keyFileSettings) This will PBKDF2 encrypt the KeyRing using the password (if the helper was created with a MessageDigestAlgorithm the password will first be hashed using that algorithm, hex encoded and changed to lowercase).
byte[]	encrypt(KeyRing keyRing, String password, String passphrase, long version) This will PBKDF2 encrypt the KeyRing using the password (if the helper was created with a MessageDigestAlgorithm the password will first be hashed using that algorithm, hex encoded and changed to lowercase).

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyFileHelper

public KeyFileHelper(MessageDigestAlgorithm passwordHashingAlgorithm)
              throws NoSuchAlgorithmException

Create a KeyFile helper that WILL hash passwords before they are used to PBKDF2 the KeyRing. NOTE: if you do not want to hash passwords, pass in null for the passwordHashingAlgorithm.

Parameters:

passwordHashingAlgorithm - the algorithm to use when hashing the password (before encrypting)

Throws:

NoSuchAlgorithmException - thrown if the algorithm is not known

Method Detail

decryptKeyRing

public KeyRing decryptKeyRing(byte[] keyFileBytes,
                              String password)
                       throws NoSuchPaddingException,
                              InvalidAlgorithmParameterException,
                              NoSuchAlgorithmException,
                              IllegalBlockSizeException,
                              BadPaddingException,
                              InvalidKeyException,
                              IOException

This will decrypt the @link KeyRing} from the formatted KeyFile data using the password (if the helper was created with a MessageDigestAlgorithm the password will first be hashed using that algorithm, hex encoded and changed to lowercase).

Parameters:

keyFileBytes - the formatted KeyFile bytes

password - the password to use to decrypt the KeyRing - see description for hashing rules

Returns:

the KeyRing from the KeyFile

Throws:

NoSuchPaddingException - thrown if the padding is not supported

InvalidAlgorithmParameterException - thrown if the cipher algorithm is not supported

NoSuchAlgorithmException - thrown if the algorithm is not supported

IllegalBlockSizeException - thrown if the cipher block size is wrong

BadPaddingException - thrown if the cipher padding is not supported

InvalidKeyException - thrown if there is an issue with the key

IOException - thrown if there was an error writing the formatted data

decryptKeyRingWithRescue

public KeyRing decryptKeyRingWithRescue(byte[] keyFileBytes,
                                        String passphrase)
                                 throws NoSuchPaddingException,
                                        InvalidAlgorithmParameterException,
                                        NoSuchAlgorithmException,
                                        IllegalBlockSizeException,
                                        BadPaddingException,
                                        InvalidKeyException,
                                        IOException

This will decrypt the @link KeyRing} from the formatted KeyFile data. First it will decrypt the rescue using the passphrase. The rescued password will then be used to decrypt the KeyRing.

Parameters:

keyFileBytes - the formatted KeyFile bytes

passphrase - the passphrase used to rescue the password

Returns:

the KeyRing from the KeyFile

Throws:

NoSuchPaddingException - thrown if the padding is not supported

InvalidAlgorithmParameterException - thrown if the cipher algorithm is not supported

NoSuchAlgorithmException - thrown if the algorithm is not supported

IllegalBlockSizeException - thrown if the cipher block size is wrong

BadPaddingException - thrown if the cipher padding is not supported

InvalidKeyException - thrown if there is an issue with the key

IOException - thrown if there was an error writing the formatted data

encrypt

public byte[] encrypt(KeyRing keyRing,
                      String password,
                      String passphrase)
               throws NoSuchPaddingException,
                      InvalidKeyException,
                      NoSuchAlgorithmException,
                      IllegalBlockSizeException,
                      BadPaddingException,
                      InvalidAlgorithmParameterException,
                      IOException

This will PBKDF2 encrypt the KeyRing using the password (if the helper was created with a MessageDigestAlgorithm the password will first be hashed using that algorithm, hex encoded and changed to lowercase). If a passphrase was included, password rescue will be included in the KeyFile format (this will allow the usage of decryptKeyRingWithRescue(byte[], String) - get the KeyRing using the passphrase). This will use KeyFileSettings.DEFAULT for the PBDKF2 parameters.

Parameters:

keyRing - the KeyRing to encrypt

password - the password to use in the PBKDF2 encryption of the KeyRing - see description for hashing rules

passphrase - the passphrase - used to encrypt the password for rescue - null if no rescue is desired

Returns:

the formatted KeyFile (with the encrypted KeyRing and optional rescue)

Throws:

NoSuchPaddingException - thrown if the padding is not supported

InvalidKeyException - thrown if there is an issue with the key

NoSuchAlgorithmException - thrown if the algorithm is not supported

IllegalBlockSizeException - thrown if the cipher block size is wrong

BadPaddingException - thrown if the cipher padding is not supported

InvalidAlgorithmParameterException - thrown if the cipher algorithm is not supported

IOException - thrown if there was an error writing the formatted data

encrypt

public byte[] encrypt(KeyRing keyRing,
                      String password,
                      String passphrase,
                      long version)
               throws NoSuchPaddingException,
                      InvalidKeyException,
                      NoSuchAlgorithmException,
                      IllegalBlockSizeException,
                      BadPaddingException,
                      InvalidAlgorithmParameterException,
                      IOException

This will PBKDF2 encrypt the KeyRing using the password (if the helper was created with a MessageDigestAlgorithm the password will first be hashed using that algorithm, hex encoded and changed to lowercase). If a passphrase was included, password rescue will be included in the KeyFile format (this will allow the usage of decryptKeyRingWithRescue(byte[], String) - get the KeyRing using the passphrase). This will use KeyFileSettings.getSettings(long) to get the correct KeyFileSettings for the PBDKF2 parameters.

Parameters:

keyRing - the KeyRing to encrypt

password - the password to use in the PBKDF2 encryption of the KeyRing - see description for hashing rules

passphrase - the passphrase - used to encrypt the password for rescue - null if no rescue is desired

version - the version of the KeyFileSettings to use for the PBKDF2 parameters

Returns:

the formatted KeyFile (with the encrypted KeyRing and optional rescue)

Throws:

NoSuchPaddingException - thrown if the padding is not supported

InvalidKeyException - thrown if there is an issue with the key

NoSuchAlgorithmException - thrown if the algorithm is not supported

IllegalBlockSizeException - thrown if the cipher block size is wrong

BadPaddingException - thrown if the cipher padding is not supported

InvalidAlgorithmParameterException - thrown if the cipher algorithm is not supported

IOException - thrown if there was an error writing the formatted data

encrypt

public byte[] encrypt(KeyRing keyRing,
                      String password,
                      String passphrase,
                      KeyFileSettings keyFileSettings)
               throws NoSuchPaddingException,
                      InvalidAlgorithmParameterException,
                      NoSuchAlgorithmException,
                      IllegalBlockSizeException,
                      BadPaddingException,
                      InvalidKeyException,
                      IOException

This will PBKDF2 encrypt the KeyRing using the password (if the helper was created with a MessageDigestAlgorithm the password will first be hashed using that algorithm, hex encoded and changed to lowercase). If a passphrase was included, password rescue will be included in the KeyFile format (this will allow the usage of decryptKeyRingWithRescue(byte[], String) - get the KeyRing using the passphrase). This will use the supplied KeyFileSettings for the PBDKF2 parameters.

Parameters:

keyRing - the KeyRing to encrypt

password - the password to use in the PBKDF2 encryption of the KeyRing - see description for hashing rules

passphrase - the passphrase - used to encrypt the password for rescue - null if no rescue is desired

keyFileSettings - the PBKDF2 parameters

Returns:

the formatted KeyFile (with the encrypted KeyRing and optional rescue)

Throws:

NoSuchPaddingException - thrown if the padding is not supported

InvalidKeyException - thrown if there is an issue with the key

NoSuchAlgorithmException - thrown if the algorithm is not supported

IllegalBlockSizeException - thrown if the cipher block size is wrong

BadPaddingException - thrown if the cipher padding is not supported

InvalidAlgorithmParameterException - thrown if the cipher algorithm is not supported

IOException - thrown if there was an error writing the formatted data