sydapi-java-sge-database/src/main/java/com/sunyard/sge/database/SydApiSM4.java

package com.sunyard.sge.database;

import com.sunyard.SydApiException;

import java.nio.ByteBuffer;

public class SydApiSM4 {

    private SydApi api;
    private int iKeyIndex;
    private byte[] pcdataResult = new byte[0];
    private int iPkgNum = 1;
    private int iFlag;
    private boolean is_finished = false;
    ByteBuffer sourceWrap = ByteBuffer.wrap(new byte[0]);


    public SydApiSM4(SydApi api, int iKeyIndex, int endeFlag) {
        this.api = api;
        this.iFlag = endeFlag;
        this.iKeyIndex = iKeyIndex;
    }

    public void update(byte[] pcData) {
        this.pcdataResult = pcData;
        if (null == pcData || pcData.length == 0) {
            return;
        }
        int plength = pcData.length;
        if (is_finished) {
            throw new SydApiException(0);
        }
        if (plength > 4064) {
            throw new SydApiException(0);
        }
        if (0 == sourceWrap.array().length) {
            //加密
            if (plength < 16) {
                api.SYD_SM4_LongData(iKeyIndex, new byte[0], iPkgNum, iFlag);
                if (iFlag == 0 && 1 == iPkgNum) {
                    throw new SydApiException("解密的首包不能小于 16 字节", 0);
                }
                ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
                bufferResult.put(sourceWrap);
                bufferResult.put(pcData);
                sourceWrap = bufferResult;
            }
            if (plength % 16 != 0) {
                ByteBuffer buffer = ByteBuffer.wrap(pcData);
                int remainder = plength % 16;
                int intercept = plength - remainder;
                byte[] bytes = new byte[intercept];
                ByteBuffer byteBuffer = buffer.get(bytes, 0, intercept);
                byte[] bytes1 = new byte[remainder];
                byteBuffer.get(bytes1);
                this.pcdataResult = bytes;
                ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + remainder);
                bufferResult.put(bytes1);
                sourceWrap = bufferResult;
            }
            byte[] bytes = api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
            iPkgNum = 2;
        } else {
            if (16 > pcData.length + sourceWrap.array().length) {
                ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
                bufferResult.put(SydSM4Mac.bytebuffer2ByteArray(sourceWrap));
                bufferResult.put(pcData);
                sourceWrap = bufferResult;
            } else if ((pcData.length + sourceWrap.array().length) % 16 == 0) {
                ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
                bufferResult.put(SydSM4Mac.bytebuffer2ByteArray(sourceWrap));
                bufferResult.put(pcData);
                byte[] bytes = SydSM4Mac.bytebuffer2ByteArray(bufferResult);
                api.SYD_SM4_LongData(iKeyIndex, bytes, iPkgNum, iFlag);
            } else {
                ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
                bufferResult.put(SydSM4Mac.bytebuffer2ByteArray(sourceWrap));
                bufferResult.put(pcData);
                byte[] bytes = SydSM4Mac.bytebuffer2ByteArray(bufferResult);
                ByteBuffer buffer = ByteBuffer.wrap(bytes);
                int remainder = bytes.length % 16;
                int intercept = bytes.length - remainder;
                byte[] pcdataByte = new byte[intercept];
                ByteBuffer byteBuffer = buffer.get(pcdataByte, 0, intercept);
                byte[] bytes1 = new byte[remainder];
                byteBuffer.get(bytes1);
                this.pcdataResult = pcdataByte;
                ByteBuffer bufferResults = ByteBuffer.allocate(remainder);
                bufferResults.put(bytes1);
                sourceWrap = bufferResults;
                api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
                iPkgNum = 2;
            }
        }
    }

    public byte[] finish() {
        if (is_finished) {
            throw new SydApiException(0);
        }
        this.is_finished = true;
        if (1 == this.iPkgNum) {
            this.iPkgNum = 0;
        } else if (2 == this.iPkgNum) {
            this.iPkgNum = 3;
        }

        byte[] bytes = api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
//        sourceWrap = null;
        return bytes;
    }

    public ByteBuffer bufferResult(int plength, byte[] pcData) {
        ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
        bufferResult.put(sourceWrap);
        bufferResult.put(pcData);
        return bufferResult;
    }
}