com.amazonaws.encryptionsdk.internal.CryptoHandler Maven / Gradle / Ivy
/*
* Copyright 2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except
* in compliance with the License. A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.amazonaws.encryptionsdk.internal;
/**
* This interface defines the contract for the implementation of encryption and decryption handlers
* in this library.
*
*
* The implementations of this interface provided in this package currently process bytes in a
* single block mode (where all input data is processed in entirety, or in a framing mode (where
* data is processed incrementally in chunks).
*/
public interface CryptoHandler {
/**
* Process a block of bytes from {@code in} putting the result into {@code out}.
*
* @param in
* the input byte array.
* @param inOff
* the offset into the {@code in} array where the data to be processed starts.
* @param inLen
* the number of bytes to be processed.
* @param out
* the output buffer the processed bytes go into.
* @param outOff
* the offset into the output byte array the processed data starts at.
* @return the number of bytes written to {@code out} and the number of bytes parsed.
*/
ProcessingSummary processBytes(final byte[] in, final int inOff, final int inLen, byte[] out, final int outOff);
/**
* Finish processing of the bytes.
*
* @param out
* the output buffer for copying any remaining output data.
* @param outOff
* offset into {@code out} to start copying the output data.
* @return number of bytes written into {@code out}.
*/
int doFinal(final byte[] out, final int outOff);
/**
* Return the size of the output buffer required for a
* {@link #processBytes(byte[], int, int, byte[], int)} plus a {@link #doFinal(byte[], int)}
* call with an input of {@code inLen) bytes.
*
*
* Note this method is allowed to return an estimation of the output size that is greater
* than the actual size of the output. Returning an estimate that is lesser than the actual size
* of the output will result in underflow exceptions.
*
* @param inLen
* the length of the input.
* @return the space required to accommodate a call to processBytes and
* {@link #doFinal(byte[], int)} with an input of size {@code inLen} bytes.
*/
int estimateOutputSize(final int inLen);
/**
* Return the size of the output buffer required for a call to
* {@link #processBytes(byte[], int, int, byte[], int)}.
*
*
* Note this method is allowed to return an estimation of the output size that is greater
* than the actual size of the output. Returning an estimate that is lesser than the actual size
* of the output will result in underflow exceptions.
*
* @param inLen
* the length of the input.
* @return the space required to accommodate a call to
* {@link #processBytes(byte[], int, int, byte[], int)} with an input of size
* {@code inLen} bytes.
*/
int estimatePartialOutputSize(final int inLen);
/**
* Return the size of the output buffer required for a call to {@link #doFinal(byte[], int)}.
*
*
* Note this method is allowed to return an estimation of the output size that is greater
* than the actual size of the output. Returning an estimate that is lesser than the actual size
* of the output will result in underflow exceptions.
*
* @return the space required to accomodate a call to {@link #doFinal(byte[], int)}
*/
int estimateFinalOutputSize();
/**
* For decrypt and parsing flows returns {@code true} when this has handled as many bytes as it
* can. This usually means that it has reached the end of an object, file, or other delimited
* stream.
*/
boolean isComplete();
}