Class CryptoGenerics

java.lang.Object

br.net.dd.netherwingcore.common.cryptography.CryptoGenerics

public final class CryptoGenerics
extends Object

Generic cryptographic utilities, not specific to any particular use case.

Method Summary

Modifier and Type	Method	Description
static byte[]	aeDecrypt_AesGcm(byte[] data, SecretKey key, int ivLenBytes, int tagLenBytes)	Decrypts the given data using AES-GCM.
static byte[]	aeEncryptWithRandomIV_AesGcm(byte[] plaintext, SecretKey key, int ivLenBytes, int tagLenBytes)	Encrypts the given plaintext using AES-GCM with a random IV.
static byte[]	appendToBack(byte[] data, byte[] tail)	Appends the given tail byte array to the back of the data byte array.
static byte[]	generateRandomIV(int ivLenBytes)	Generates a random IV of the specified length in bytes.

Methods inherited from class Object

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

Method Details

generateRandomIV

public static byte[] generateRandomIV(int ivLenBytes)

Generates a random IV of the specified length in bytes.

Parameters:

ivLenBytes - The length of the IV in bytes (e.g., 12 for AES-GCM).

Returns:

A byte array containing the random IV.

appendToBack

public static byte[] appendToBack(byte[] data,
 byte[] tail)

Appends the given tail byte array to the back of the data byte array.

Parameters:

data - The original byte array.

tail - The byte array to append to the back of data.

Returns:

A new byte array containing data followed by tail.

aeEncryptWithRandomIV_AesGcm

public static byte[] aeEncryptWithRandomIV_AesGcm(byte[] plaintext,
 SecretKey key,
 int ivLenBytes,
 int tagLenBytes)
                                           throws GeneralSecurityException

Encrypts the given plaintext using AES-GCM with a random IV. The output format is: [ciphertext][IV][tag]

Parameters:

plaintext - The plaintext to encrypt.

key - The secret key for encryption.

ivLenBytes - The length of the IV in bytes (e.g., 12 for AES-GCM).

tagLenBytes - The length of the authentication tag in bytes (e.g., 16 for 128-bit tag).

Returns:

A byte array containing the ciphertext followed by the IV and then the tag.

Throws:

GeneralSecurityException - If encryption fails or if the ciphertext is shorter than the tag.

aeDecrypt_AesGcm

public static byte[] aeDecrypt_AesGcm(byte[] data,
 SecretKey key,
 int ivLenBytes,
 int tagLenBytes)
                               throws GeneralSecurityException

Decrypts the given data using AES-GCM. The input format is expected to be: [ciphertext][IV][tag]

Parameters:

data - The data to decrypt, containing the ciphertext followed by the IV and then the tag.

key - The secret key for decryption.

ivLenBytes - The length of the IV in bytes (e.g., 12 for AES-GCM).

tagLenBytes - The length of the authentication tag in bytes (e.g., 16 for 128-bit tag).

Returns:

A byte array containing the decrypted plaintext.

Throws:

GeneralSecurityException - If decryption fails or if the input data is too short to contain the IV and tag.