Ejemplo n.º 1
0
 public BlockStreamCrypter(Idea idea, bool encrypt)
 {
     this.idea = idea;
     this.encrypt = encrypt;
     prev = new byte[blockSize];
     newPrev = new byte[blockSize];
 }
Ejemplo n.º 2
0
 /**
  * Encrypts or decrypts a file.
  *
  * @param inputFileName
  *    Name of the input file.
  * @param outputFileName
  *    Name of the output file.
  * @param charKey
  *    The encryption key. A string of ASCII characters within the range 0x21 .. 0x7E.
  * @param encrypt
  *    true to encrypt, false to decrypt.
  * @param mode
  *    Mode of operation.
  */
 public static void cryptFile(String inputFileName, String outputFileName, String charKey, bool encrypt)
 {
     FileStream inStream = null;
     FileStream outStream = null;
     try
     {
         Idea idea = new Idea(charKey, encrypt);
         BlockStreamCrypter bsc = new BlockStreamCrypter(idea, encrypt);
         inStream = new FileStream(inputFileName, FileMode.Open, FileAccess.ReadWrite);
         long inFileSize = inStream.Length;
         long inDataLen;
         long outDataLen;
         if (encrypt)
         {
             inDataLen = inFileSize;
             outDataLen = (inDataLen + blockSize - 1) / blockSize * blockSize;
         }
         else
         {
             if (inFileSize == 0)
             {
                 throw new IOException("Input file is empty.");
             }
             if (inFileSize % blockSize != 0)
             {
                 throw new IOException("Input file size is not a multiple of " + blockSize + ".");
             }
             inDataLen = inFileSize - blockSize;
             outDataLen = inDataLen;
         }
         outStream = new FileStream(outputFileName, FileMode.Create, FileAccess.Write);
         processData(inStream, inDataLen, outStream, outDataLen, bsc);
         if (encrypt)
         {
             writeDataLength(outStream, inDataLen, bsc);
         }
         else
         {
             long outFileSize = readDataLength(inStream, bsc);
             if (outFileSize < 0 || outFileSize > inDataLen || outFileSize < inDataLen - blockSize + 1)
             {
                 throw new IOException("Input file is not a valid cryptogram.");
             }
             if (outFileSize != outDataLen)
             {
                 outStream.SetLength(outFileSize);
             }
         }
         outStream.Close();
     }
     finally
     {
         if (inStream != null)
         {
             inStream.Close();
         }
         if (outStream != null)
         {
             outStream.Close();
         }
     }
 }
Ejemplo n.º 3
0
        /**
         * Encrypts or decrypts a file.
         *
         * @param inputFileName
         *    Name of the input file.
         * @param outputFileName
         *    Name of the output file.
         * @param charKey
         *    The encryption key. A string of ASCII characters within the range 0x21 .. 0x7E.
         * @param encrypt
         *    true to encrypt, false to decrypt.
         * @param mode
         *    Mode of operation.
         */
        public static void cryptFile(String inputFileName, String outputFileName, String charKey, bool encrypt)
        {
            FileStream inStream  = null;
            FileStream outStream = null;

            try
            {
                Idea idea = new Idea(charKey, encrypt);
                BlockStreamCrypter bsc = new BlockStreamCrypter(idea, encrypt);
                inStream = new FileStream(inputFileName, FileMode.Open, FileAccess.ReadWrite);
                long inFileSize = inStream.Length;
                long inDataLen;
                long outDataLen;
                if (encrypt)
                {
                    inDataLen  = inFileSize;
                    outDataLen = (inDataLen + blockSize - 1) / blockSize * blockSize;
                }
                else
                {
                    if (inFileSize == 0)
                    {
                        throw new IOException("Input file is empty.");
                    }
                    if (inFileSize % blockSize != 0)
                    {
                        throw new IOException("Input file size is not a multiple of " + blockSize + ".");
                    }
                    inDataLen  = inFileSize - blockSize;
                    outDataLen = inDataLen;
                }
                outStream = new FileStream(outputFileName, FileMode.Create, FileAccess.Write);
                processData(inStream, inDataLen, outStream, outDataLen, bsc);
                if (encrypt)
                {
                    writeDataLength(outStream, inDataLen, bsc);
                }
                else
                {
                    long outFileSize = readDataLength(inStream, bsc);
                    if (outFileSize < 0 || outFileSize > inDataLen || outFileSize < inDataLen - blockSize + 1)
                    {
                        throw new IOException("Input file is not a valid cryptogram.");
                    }
                    if (outFileSize != outDataLen)
                    {
                        outStream.SetLength(outFileSize);
                    }
                }
                outStream.Close();
            }
            finally
            {
                if (inStream != null)
                {
                    inStream.Close();
                }
                if (outStream != null)
                {
                    outStream.Close();
                }
            }
        }