public BlockStreamCrypter(Idea idea, bool encrypt)
{
this.idea = idea;
this.encrypt = encrypt;
prev = new byte[blockSize];
newPrev = new byte[blockSize];
}
/**
* 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();
}
}
}
/**
* 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();
}
}
}
