Documentation Update: Clarify SM2/SM9 Encryption and Decryption Processes

Author: liyongfei

src/main/java/org/gmssl/crypto/asymmetric/SM2Cipher.java

@@ -117,6 +117,19 @@ protected byte[] engineUpdate(byte[] input, int inputOffset, int inputLen) {
         return null;
     }
 
+    /**
+     * The method does not perform any encryption or decryption; it only stores the input data. The returned result is meaningless, and the final result is output through `doFinal`.
+     * @param input the input buffer
+     * @param inputOffset the offset in <code>input</code> where the input
+     * starts
+     * @param inputLen the input length
+     * @param output the buffer for the result
+     * @param outputOffset the offset in <code>output</code> where the result
+     * is stored
+     *
+     * @return
+     * @throws ShortBufferException
+     */
     @Override
     protected int engineUpdate(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset) throws ShortBufferException {
         if (input == null || inputOffset < 0 || inputLen < 0 || inputOffset + inputLen > input.length) {

src/main/java/org/gmssl/crypto/asymmetric/SM9Cipher.java

@@ -109,13 +109,12 @@ protected void engineInit(int opmode, Key key, AlgorithmParameters params, Secur
     }
 
     /**
-     *
+     * SM9 encryption and decryption are completed during the engineDoFinal phase. During the update phase, data is only cached, and no partial encryption or decryption results are returned.
      * @param input the input buffer
      * @param inputOffset the offset in <code>input</code> where the input
      * starts
      * @param inputLen the input length
-     * @description
-     * SM9 encryption and decryption are completed during the engineDoFinal phase. During the update phase, data is only cached, and no partial encryption or decryption results are returned.
+     *
      * @return
      */
     @Override
@@ -124,6 +123,19 @@ protected byte[] engineUpdate(byte[] input, int inputOffset, int inputLen) {
         return null;
     }
 
+    /**
+     * SM9 encryption and decryption are completed during the engineDoFinal phase. During the update phase, data is only cached, and no partial encryption or decryption results are returned.
+     * @param input the input buffer
+     * @param inputOffset the offset in <code>input</code> where the input
+     * starts
+     * @param inputLen the input length
+     * @param output the buffer for the result
+     * @param outputOffset the offset in <code>output</code> where the result
+     * is stored
+     *
+     * @return
+     * @throws ShortBufferException
+     */
     @Override
     protected int engineUpdate(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset) throws ShortBufferException {
         buffer.put(input, inputOffset, inputLen);