rsaencryption.java

对称和非对称加密

            System.arraycopy(paddZero, 0, dest, 0, padCount);
            System.arraycopy(tempc, 0, dest, padCount, length);
          }
          else {
            System.arraycopy(tempc, 0, dest, padCount, length);
          }
          //
          fOutput.write(dest, 0, 128);

        } // if
      }
      //
      ret = true;
      fInput.close();
        fOutput.close();

    }

    catch (FileNotFoundException ex) {
      throw new FileNotFoundException("file not found");
    }
    catch (IOException ex) {
      throw new IOException("IO  Exception");
    }


    return ret;
  }

  /**
   * 第四种方式:加密文件
   * @param nfilename RSA大整数模的文件
   * @param efilename RSA加密指数的文件
   * @param inFile 要加密的文件
   * @param outFile  输出的密文文件
   * @return  真,操作成功,假,操作失败
   * @throws FileNotFoundException 文件异常
   * @throws IOException 输入输出异常
   */
  public boolean FileEncryptionF(String nfilename, String efilename,
                                 String inFile, String outFile) throws
      FileNotFoundException, IOException {
    boolean ret = false;
    // 加密指数  模
    DmgcMpInteger ee = null;
    DmgcMpInteger nn = null;
    FileInputStream fInputN = null;
    FileInputStream fInputE = null;
    // 密钥文件

    try {
      fInputE = new FileInputStream(efilename);
      fInputN = new FileInputStream(nfilename);

      int lengthN = fInputN.available();
      int lengthE = fInputE.available();
      byte[] BufferN = new byte[lengthN];
      byte[] BufferE = new byte[lengthE];
       lengthN = fInputN.read(BufferN);
       lengthE = fInputE.read(BufferE);
      byte[] N = new byte[lengthN];
      System.arraycopy(BufferN, 0, N, 0, lengthN);
      byte[] E = new byte[lengthE];
      System.arraycopy(BufferE, 0, E, 0, lengthE);
      ee = new DmgcMpInteger(E);
      nn = new DmgcMpInteger(N);
      fInputN.close();
      fInputE.close();
    }
    catch (FileNotFoundException ex) {
      throw new FileNotFoundException("file not found");
    }
    catch (IOException ex) {
      throw new IOException("IO  Exception");
    }

    // 文件加密
    //
    byte[] dest = new byte[128];
    byte[] org = new byte[128];
    byte[] temp = new byte[117];
    //
    byte[] buffer = new byte[7488];
    int bufferLength = 0;
    //
    FileInputStream fInput = null;
    FileOutputStream fOutput = null;
    //
    try {
      //  输入文件
      fInput = new FileInputStream(inFile);
      //  输出文件
      fOutput = new FileOutputStream(outFile);

      //
      while ( (bufferLength = fInput.read(buffer)) != -1) {
        int i = 0;
        for (i = 0; i < bufferLength; i = i + 117) {
          // 每次读取117个字节
          // 如果取到最后一次,则跳出
          if (i + 117 >bufferLength) {
            break;
          }
          // 每次117字节
          System.arraycopy(buffer, i, temp, 0, 117);
          // 开头两位标志位
          org[0] = 0x00;
          org[1] = 0x02;
          int padCount = 8; //128 -length - 3;
          // 填空位
          byte[] padding = getPadding(padCount);
          System.arraycopy(padding, 0, org, 2, padCount);
          //标志位
          org[padCount + 2] = 0x00;
          //明文位
          System.arraycopy(temp, 0, org, padCount + 3, 117);
          // 加密
          DmgcMpInteger ppp = new DmgcMpInteger(org);
          DmgcMpInteger cc = ppp.modPow(ee, nn);
          // 如果密文不是128字节也要填充0x00
          byte[] tempc = cc.toByteArray();
          int length = tempc.length;
          padCount = 128 - length;
          if (padCount > 0) {
            byte[] paddZero = new byte[padCount];
//            for (int j = 0; j < padCount; j++) {
//              paddZero[j] = 0x00;
//            }
            System.arraycopy(paddZero, 0, dest, 0, padCount);
            System.arraycopy(tempc, 0, dest, padCount, length);
          }
          else {
            System.arraycopy(tempc, 0, dest, padCount, length);
          }
          //
          fOutput.write(dest, 0, 128);

        } // end for
        // 如果有多余字节则进行下面操作
        if ( (i !=0)&&(i < bufferLength) && ( (bufferLength - i) > 0)) {
          int length = bufferLength - i;
          System.arraycopy(buffer, i, temp, 0, length);
          byte[] temp2 = new byte[length];
          System.arraycopy(temp, 0, temp2, 0, length);
          // 开头两位标志位
          org[0] = 0x00;
          org[1] = 0x02;
          int padCount = 128 - length - 3;
          // 填空位
          byte[] padding = getPadding(padCount);
          System.arraycopy(padding, 0, org, 2, padCount);
          //标志位
          org[padCount + 2] = 0x00;
          //明文位
          System.arraycopy(temp2, 0, org, padCount + 3, length);
          //加密
          DmgcMpInteger ppp = new DmgcMpInteger(org);
          DmgcMpInteger cc = ppp.modPow(ee, nn);
          // 如果密文不是128字节也要填充0x00
          byte[] tempc = cc.toByteArray();
          length = tempc.length;
          padCount = 128 - length;
          if (padCount > 0) {
            byte[] paddZero = new byte[padCount];
//            for (int j = 0; j < padCount; j++) {
//              paddZero[j] = 0x00;
//            }
            System.arraycopy(paddZero, 0, dest, 0, padCount);
            System.arraycopy(tempc, 0, dest, padCount, length);
          }
          else {
            System.arraycopy(tempc, 0, dest, padCount, length);
          }
          //
          fOutput.write(dest, 0, 128);

        } // if
      }
      //
      fInput.close();
      fOutput.close();
      ret = true;

    }

    catch (FileNotFoundException ex) {
      throw new FileNotFoundException("file not found");
    }
    catch (IOException ex) {
      throw new IOException("IO  Exception");
    }


    return ret;

  }

  //----------------------------------------------------------------------------
  /**
   * 加密字符串
   * @param keyfilename  公钥文件 n e
   * @param plainText 明文,小于等于117字节
   * @return 密文字节,128位
   * @throws MessageTooLongException 消息太长
   * @throws FileNotFoundException  文件没有找到
   * @throws IOException  IO 异常
   * @throws InvalidKeyFileException 无效的公钥文件
   */
  public byte[] NewMessageEncryptionF(String keyfilename,
                                      byte[] plainText) throws
      MessageTooLongException, FileNotFoundException,
      InvalidKeyFileException, IOException {
    //--------------------------------------------------------------------
    //    byte[] ret = new byte[128];
    //
    FileInputStream fInputKey = new FileInputStream(keyfilename);
    int length = fInputKey.available();
    if (length <= 128) {
      throw new InvalidKeyFileException("Invalid Key file Exception");
    }
    //
    byte[] Buffer = new byte[128];
    //
    int lengthN = fInputKey.read(Buffer);

    byte[] N = new byte[lengthN];
    System.arraycopy(Buffer, 0, N, 0, lengthN);

    lengthN = fInputKey.read(Buffer);
    byte[] E = new byte[lengthN];
    System.arraycopy(Buffer, 0, E, 0, lengthN);

    fInputKey.close();

    DmgcMpInteger NN = new DmgcMpInteger(N);
    DmgcMpInteger EE = new DmgcMpInteger(E);
    // 以上为读取公钥
    // ------------------------------------------------------------------------
    byte[] ret = MessageEncryption(NN.toString(),EE.toString(),plainText);
//    System.out.println(NN.toString());
//    System.out.println(EE.toString());

    return ret;
  }

  /**
   * 加密文件
   * @param keyfilename 密钥文件 n e
   * @param inFile  输入文件
   * @param outFile 输出文件
   * @return  真,操作成功,假,操作失败
   * @throws FileNotFoundException 文件异常
   * @throws InvalidKeyFileException 无效的密钥异常
   * @throws IOException IO 异常
   */
  public boolean NewFileEncryptionF(String keyfilename,
                                 String inFile, String outFile) throws
      FileNotFoundException,InvalidKeyFileException, IOException {

   //--------------------------------------------------------------------
   //    byte[] ret = new byte[128];
   //
  FileInputStream fInputKey = null;
  try {
    fInputKey = new FileInputStream(keyfilename);
  }
  catch (FileNotFoundException ex) {
    throw new FileNotFoundException("File not found!");
  }
   int length = fInputKey.available();
   if (length <= 128) {
     throw new InvalidKeyFileException("Invalid Key file Exception");
   }
   //
   byte[] Buffer = new byte[128];
   //
   int lengthN = fInputKey.read(Buffer);

   byte[] N = new byte[lengthN];
   System.arraycopy(Buffer, 0, N, 0, lengthN);

   lengthN = fInputKey.read(Buffer);
   byte[] E = new byte[lengthN];
   System.arraycopy(Buffer, 0, E, 0, lengthN);

   fInputKey.close();

   DmgcMpInteger NN = new DmgcMpInteger(N);
   DmgcMpInteger EE = new DmgcMpInteger(E);
   // 以上为读取公钥
   // ------------------------------------------------------------------------
   boolean ret = FileEncryption(NN.toString(),EE.toString(),inFile,outFile);

   return ret;

  }


  //----------------------------------------------------------------------------

}