Package org.cryptomator.cryptolib

Class Cryptors

java.lang.Object

org.cryptomator.cryptolib.Cryptors

public final class Cryptors
extends Object

Constructor Summary

Constructors

Constructor	Description
Cryptors()

Method Summary

Modifier and Type	Method	Description
static byte[]	changePassphrase(CryptorProvider cryptoProvider, byte[] masterkey, byte[] pepper, CharSequence oldPassphrase, CharSequence newPassphrase)	Reencrypts a masterkey with a new passphrase.
static byte[]	changePassphrase(CryptorProvider cryptoProvider, byte[] masterkey, CharSequence oldPassphrase, CharSequence newPassphrase)	Reencrypts a masterkey with a new passphrase.
static long	ciphertextSize(long cleartextSize, Cryptor cryptor)	Calculates the size of the ciphertext resulting from the given cleartext encrypted with the given cryptor.
static long	cleartextSize(long ciphertextSize, Cryptor cryptor)	Calculates the size of the cleartext resulting from the given ciphertext decrypted with the given cryptor.
static CryptorProvider	version1(SecureRandom seeder)

Methods inherited from class java.lang.Object

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

Constructor Detail

Cryptors

public Cryptors()

Method Detail

version1

public static CryptorProvider version1(SecureRandom seeder)

Parameters:

seeder - A native (if possible) SecureRandom used to seed internal CSPRNGs.

Returns:

A version 1 CryptorProvider

cleartextSize

public static long cleartextSize(long ciphertextSize,
                                 Cryptor cryptor)

Calculates the size of the cleartext resulting from the given ciphertext decrypted with the given cryptor.

Parameters:

ciphertextSize - Length of encrypted payload. Not including the length of the header.

cryptor - The cryptor which defines the cleartext/ciphertext ratio

Returns:

Cleartext length of a ciphertextSize-sized ciphertext decrypted with cryptor.

ciphertextSize

public static long ciphertextSize(long cleartextSize,
                                  Cryptor cryptor)

Calculates the size of the ciphertext resulting from the given cleartext encrypted with the given cryptor.

Parameters:

cleartextSize - Length of a unencrypted payload.

cryptor - The cryptor which defines the cleartext/ciphertext ratio

Returns:

Ciphertext length of a cleartextSize-sized cleartext encrypted with cryptor. Not including the length of the header.

changePassphrase

public static byte[] changePassphrase(CryptorProvider cryptoProvider,
                                      byte[] masterkey,
                                      CharSequence oldPassphrase,
                                      CharSequence newPassphrase)
                               throws InvalidPassphraseException

Reencrypts a masterkey with a new passphrase.

Parameters:

cryptoProvider - A suitable CryptorProvider instance, i.e. same version as the original masterkey has been created with.

masterkey - The original JSON representation of the masterkey

oldPassphrase - The old passphrase

newPassphrase - The new passphrase

Returns:

A JSON representation of the masterkey, now encrypted with newPassphrase

Throws:

InvalidPassphraseException - If the wrong oldPassphrase has been supplied for the masterkey

Since:

1.1.0

See Also:

changePassphrase(CryptorProvider, byte[], byte[], CharSequence, CharSequence)

changePassphrase

public static byte[] changePassphrase(CryptorProvider cryptoProvider,
                                      byte[] masterkey,
                                      byte[] pepper,
                                      CharSequence oldPassphrase,
                                      CharSequence newPassphrase)
                               throws InvalidPassphraseException

Reencrypts a masterkey with a new passphrase.

Parameters:

cryptoProvider - A suitable CryptorProvider instance, i.e. same version as the original masterkey has been created with.

masterkey - The original JSON representation of the masterkey

pepper - An application-specific pepper added to the salt during key-derivation (if applicable)

oldPassphrase - The old passphrase

newPassphrase - The new passphrase

Returns:

A JSON representation of the masterkey, now encrypted with newPassphrase

Throws:

InvalidPassphraseException - If the wrong oldPassphrase has been supplied for the masterkey

Since:

1.1.4