Example usage for javax.crypto.spec GCMParameterSpec GCMParameterSpec

Introduction

In this page you can find the example usage for javax.crypto.spec GCMParameterSpec GCMParameterSpec.

Prototype

public GCMParameterSpec(int tLen, byte[] src, int offset, int len) 

Source Link

Document

Constructs a GCMParameterSpec object using the specified authentication tag bit-length and a subset of the specified buffer as the IV.

Usage

From source file:com.demandware.appsec.csrf.StatelessCSRFTokenManager.java

/**
 * encrypts or decrypts using AES/GCM and the given values
 *
 * @param key the key to use with *crypting
 * @param iv the iv to use when *crypting
 * @param textBytes the encrypted value to be decrypted OR the plaintext to be encrypted
 * @param mode either {@link Cipher#ENCRYPT_MODE} or {@link Cipher#DECRYPT_MODE}
 * @return the encrypted or decrypted value, depending on the given mode
 * @throws NoSuchAlgorithmException if the underlying code throws this exception
 * @throws NoSuchPaddingException if the underlying code throws this exception
 * @throws InvalidKeyException if the underlying code throws this exception
 * @throws InvalidAlgorithmParameterException if the underlying code throws this exception
 * @throws IllegalBlockSizeException if the underlying code throws this exception
 * @throws BadPaddingException if the underlying code throws this exception
 * @throws UnsupportedEncodingException if the underlying code throws this exception
 *//*from  w  w  w . j a  v a 2  s .  c o m*/
private byte[] crypt(byte[] key, byte[] iv, byte[] textBytes, int mode) throws NoSuchAlgorithmException,
        NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException,
        IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
    byte[] cryptedValue = null;
    Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
    SecretKeySpec keyspec = new SecretKeySpec(key, 0, KEY_SIZE, "AES");
    GCMParameterSpec gcmspec = new GCMParameterSpec(GCM_TAG_BITS, iv, 0, PARAMETER_SPEC_SIZE);
    cipher.init(mode, keyspec, gcmspec);
    cryptedValue = cipher.doFinal(textBytes);
    return cryptedValue;
}

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