at.favre.lib.armadillo

Interface AuthenticatedEncryption

public interface AuthenticatedEncryption

Authenticated encryption (AE) and authenticated encryption with associated data (AEAD, variant of AE) is a form of encryption which simultaneously provides confidentiality, integrity, and authenticity assurances on the data. These attributes are provided under a single, easy to use programming interface.

See: https://en.wikipedia.org/wiki/Authenticated_encryption

Since:

18.12.2017

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	AuthenticatedEncryption.KeyStrength

Field Summary

Fields

Modifier and Type	Field and Description
static int	STRENGTH_HIGH High Security which is equivalent to a AES key size of 128 bit
static int	STRENGTH_VERY_HIGH Very high security which is equivalent to a AES key size of 256 bit Note: This is usually not required.

Method Summary

Modifier and Type	Method and Description
int	byteSizeLength(int keyStrengthType) Get the required key size length in bytes for given security strength type
byte[]	decrypt(byte[] rawEncryptionKey, byte[] encryptedData, byte[] associatedData) Decrypt and verifies the authenticity of given encrypted data
byte[]	encrypt(byte[] rawEncryptionKey, byte[] rawData, byte[] associatedData) Encrypts and adds a authentication tag the given content

Field Detail

STRENGTH_HIGH

static final int STRENGTH_HIGH

High Security which is equivalent to a AES key size of 128 bit

See Also:

Constant Field Values

STRENGTH_VERY_HIGH

static final int STRENGTH_VERY_HIGH

Very high security which is equivalent to a AES key size of 256 bit Note: This is usually not required.

See Also:

Constant Field Values

Method Detail

encrypt

byte[] encrypt(byte[] rawEncryptionKey,
               byte[] rawData,
               byte[] associatedData)
        throws AuthenticatedEncryptionException

Encrypts and adds a authentication tag the given content

Parameters:

rawEncryptionKey - to use as encryption key material

rawData - to encrypt

associatedData - additional data used to create the auth tag and will be subject to integrity/authentication check

Returns:

encrypted content

Throws:

AuthenticatedEncryptionException - if any crypto fails

decrypt

byte[] decrypt(byte[] rawEncryptionKey,
               byte[] encryptedData,
               byte[] associatedData)
        throws AuthenticatedEncryptionException

Decrypt and verifies the authenticity of given encrypted data

Parameters:

rawEncryptionKey - to use as decryption key material

encryptedData - to decrypt

associatedData - additional data used to create the auth tag; must be same as provided in the encrypt step

Returns:

decrypted, original data

Throws:

AuthenticatedEncryptionException - if any crypto fails

byteSizeLength

int byteSizeLength(int keyStrengthType)

Get the required key size length in bytes for given security strength type

Parameters:

keyStrengthType - STRENGTH_HIGH or STRENGTH_VERY_HIGH

Returns:

required size in byte