diff --git a/src/main/java/com/sunyard/sge/database/SydApiSM4.java b/src/main/java/com/sunyard/sge/database/SydApiSM4.java
index 71d5528..893f60d 100644
--- a/src/main/java/com/sunyard/sge/database/SydApiSM4.java
+++ b/src/main/java/com/sunyard/sge/database/SydApiSM4.java
@@ -13,6 +13,7 @@ public class SydApiSM4 {
     private int iFlag;
     private boolean is_finished = false;
     private byte[] dataResult = new byte[0];
+
     ByteBuffer sourceWrap = ByteBuffer.wrap(new byte[0]);
 
 
@@ -35,67 +36,132 @@ public class SydApiSM4 {
         if (plength > 4064) {
             throw new SydApiException(0);
         }
+        if (iFlag == 1) {
         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);
+                //加密
+                if (plength < 16) {
+                    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;
                 }
-                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;
-            }
-             iPkgNum = 2;
-             return api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
 
-        } else {
-            if (16 > pcData.length + sourceWrap.array().length) {
-                ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
-                bufferResult.put(sourceWrap.array());
-                bufferResult.put(pcData);
-                sourceWrap = bufferResult;
-                return new byte[0];
-            } else if ((pcData.length + sourceWrap.array().length) % 16 == 0) {
-                ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
-                bufferResult.put(sourceWrap.array());
-                bufferResult.put(pcData);
-                byte[] bytes = SydSM4Mac.bytebuffer2ByteArray(bufferResult);
-                return api.SYD_SM4_LongData(iKeyIndex, bytes, iPkgNum, iFlag);
-            } else {
-                ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
-                bufferResult.put(sourceWrap.array());
-                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;
                 iPkgNum = 2;
-                return  api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
+                return api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
+
+            } else {
+                if (16 > pcData.length + sourceWrap.array().length) {
+                    ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
+                    bufferResult.put(sourceWrap.array());
+                    bufferResult.put(pcData);
+                    sourceWrap = bufferResult;
+                    return new byte[0];
+                } else if ((pcData.length + sourceWrap.array().length) % 16 == 0) {
+                    ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
+                    bufferResult.put(sourceWrap.array());
+                    bufferResult.put(pcData);
+                    byte[] bytes = SydSM4Mac.bytebuffer2ByteArray(bufferResult);
+                    return api.SYD_SM4_LongData(iKeyIndex, bytes, iPkgNum, iFlag);
+                } else {
+                    ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
+                    bufferResult.put(sourceWrap.array());
+                    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;
+                    iPkgNum = 2;
+                    return api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
+                }
             }
         }
+        else {
+            if (0 == sourceWrap.array().length) {
+                if (plength<16){
+                    api.SYD_SM4_LongData(iKeyIndex, new byte[0], iPkgNum, iFlag);
+                    ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
+                    bufferResult.put(sourceWrap);
+                    bufferResult.put(pcData);
+                    sourceWrap = bufferResult;
+                }
+                    ByteBuffer buffer = ByteBuffer.wrap(pcData);
+                    int remainder = plength % 16;
+                    int intercept = plength - remainder - 16;
+                    byte[] bytes = new byte[intercept];
+                    ByteBuffer byteBuffer = buffer.get(bytes, 0, intercept);
+                    byte[] bytes1 = new byte[remainder];
+                    byteBuffer.get(bytes1);
+                    byte[] bytes2 = new byte[16];
+                    ByteBuffer byte1 = buffer.get(bytes2,0,16);
+                    dataResult=bytes2;
+                    this.pcdataResult = bytes;
+                    ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + remainder);
+                    bufferResult.put(bytes1);
+                    sourceWrap = bufferResult;
+
+                iPkgNum = 2;
+
+                return api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
+
+            } else {
+                if (16 > pcData.length + sourceWrap.array().length) {
+                    ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
+                    bufferResult.put(sourceWrap.array());
+                    bufferResult.put(pcData);
+                    sourceWrap = bufferResult;
+                    return new byte[0];
+                } else if ((pcData.length + sourceWrap.array().length) % 16 == 0) {
+                    ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
+                    bufferResult.put(sourceWrap.array());
+                    bufferResult.put(pcData);
+                    byte[] bytes = SydSM4Mac.bytebuffer2ByteArray(bufferResult);
+                    return api.SYD_SM4_LongData(iKeyIndex, bytes, iPkgNum, iFlag);
+                } else {
+                    ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
+                    bufferResult.put(sourceWrap.array());
+                    bufferResult.put(pcData);
+                    byte[] bytes = SydSM4Mac.bytebuffer2ByteArray(bufferResult);
+                    ByteBuffer buffer = ByteBuffer.wrap(bytes);
+                    int remainder = bytes.length % 16;
+                    int intercept = bytes.length - remainder - 16;
+                    byte[] pcdataByte = new byte[intercept];
+                    ByteBuffer byteBuffer = buffer.get(pcdataByte, 0, intercept);
+                    byte[] bytes1 = new byte[remainder];
+                    byteBuffer.get(bytes1);
+                    byte[] bytes2 = new byte[16];
+                    ByteBuffer byteBuffer2 = buffer.get(bytes2, 0, 16);
+                    this.dataResult = bytes2;
+                    this.pcdataResult = pcdataByte;
+                    ByteBuffer bufferResults = ByteBuffer.allocate(remainder);
+                    bufferResults.put(bytes1);
+                    sourceWrap = bufferResults;
+                    iPkgNum = 2;
+                    return api.SYD_SM4_LongData(iKeyIndex, pcdataResult, iPkgNum, iFlag);
+                }
+            }
+        }
+
     }
 
     public byte[] finish() {
@@ -109,6 +175,15 @@ public class SydApiSM4 {
             this.iPkgNum = 3;
         }
 
+
+        if (iFlag == 0){
+            ByteBuffer buffer = ByteBuffer.allocate(dataResult.length+sourceWrap.array().length);
+            buffer.put(dataResult);
+            buffer.put(sourceWrap.array());
+            byte[] bytes = api.SYD_SM4_LongData(iKeyIndex,buffer.array(), iPkgNum, iFlag);
+            sourceWrap = null;
+            return bytes;
+        }
         byte[] bytes = api.SYD_SM4_LongData(iKeyIndex,sourceWrap.array(), iPkgNum, iFlag);
         sourceWrap = null;
         return bytes;