com.nimbusds.jose.crypto.impl.AAD Maven / Gradle / Ivy
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/*
* nimbus-jose-jwt
*
* Copyright 2012-2016, Connect2id Ltd and contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use
* this file except in compliance with the License. You may obtain a copy of the
* License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed
* under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
* CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
*/
package com.nimbusds.jose.crypto.impl;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import com.nimbusds.jose.JWEHeader;
import com.nimbusds.jose.util.Base64URL;
import com.nimbusds.jose.util.ByteUtils;
import com.nimbusds.jose.util.IntegerOverflowException;
/**
* Additional authenticated data (AAD).
*
* See RFC 7518 (JWA), section 5.1, point 14.
*
* @author Vladimir Dzhuvinov
* @version 2017-06-01
*/
public class AAD {
/**
* Computes the Additional Authenticated Data (AAD) for the specified
* JWE header.
*
* @param jweHeader The JWE header. Must not be {@code null}.
*
* @return The AAD.
*/
public static byte[] compute(final JWEHeader jweHeader) {
return compute(jweHeader.toBase64URL());
}
/**
* Computes the Additional Authenticated Data (AAD) for the specified
* BASE64URL-encoded JWE header.
*
* @param encodedJWEHeader The BASE64URL-encoded JWE header. Must not
* be {@code null}.
*
* @return The AAD.
*/
public static byte[] compute(final Base64URL encodedJWEHeader) {
return encodedJWEHeader.toString().getBytes(StandardCharsets.US_ASCII);
}
/**
* Computes the bit length of the specified Additional Authenticated
* Data (AAD). Used in AES/CBC/PKCS5Padding/HMAC-SHA2 encryption.
*
* @param aad The Additional Authenticated Data (AAD). Must not be
* {@code null}.
*
* @return The computed AAD bit length, as a 64 bit big-endian
* representation (8 byte array).
*
* @throws IntegerOverflowException On a integer overflow.
*/
public static byte[] computeLength(final byte[] aad)
throws IntegerOverflowException {
final int bitLength = ByteUtils.safeBitLength(aad);
return ByteBuffer.allocate(8).putLong(bitLength).array();
}
}