private static long readDataLength(FileStream stream, BlockStreamCrypter bsc)
{
byte[] buf = new byte[blockSize];
int trLen = stream.Read(buf, 0, blockSize);
if (trLen != blockSize)
{
throw new Exception("Unable to read data length suffix.");
}
bsc.crypt(buf, 0);
return(unpackDataLength(buf));
}
/**
* 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();
}
}
}
private static void writeDataLength(FileStream stream, long dataLength, BlockStreamCrypter bsc)
{
byte[] a = packDataLength(dataLength);
bsc.crypt(a, 0);
stream.Write(a, 0, blockSize);
}
private static long readDataLength(FileStream stream, BlockStreamCrypter bsc)
{
byte[] buf = new byte[blockSize];
int trLen = stream.Read(buf, 0, blockSize);
if (trLen != blockSize)
{
throw new Exception("Unable to read data length suffix.");
}
bsc.crypt(buf, 0);
return unpackDataLength(buf);
}
private static void processData(FileStream inStream, long inDataLen, FileStream outStream, long outDataLen, BlockStreamCrypter bsc)
{
int bufSize = 0x200000;
byte[] buf = new byte[bufSize];
long filePos = 0;
while (filePos < inDataLen)
{
int reqLen = (int)Math.Min(inDataLen - filePos, bufSize);
int trLen = inStream.Read(buf, 0, reqLen);
if (trLen != reqLen)
{
throw new Exception("Incomplete data chunk read from file.");
}
int chunkLen = (trLen + blockSize - 1) / blockSize * blockSize;
for (int i = trLen; i <= chunkLen; i++)
{
buf[i] = 0;
}
for (int pos = 0; pos < chunkLen; pos += blockSize)
{
bsc.crypt(buf, pos);
}
reqLen = (int)Math.Min(outDataLen - filePos, chunkLen);
outStream.Write(buf, 0, reqLen);
filePos += chunkLen;
}
}
/**
* 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();
}
}
}
private static void writeDataLength(FileStream stream, long dataLength, BlockStreamCrypter bsc)
{
byte[] a = packDataLength(dataLength);
bsc.crypt(a, 0);
stream.Write(a, 0, blockSize);
}
private static void processData(FileStream inStream, long inDataLen, FileStream outStream, long outDataLen, BlockStreamCrypter bsc)
{
int bufSize = 0x200000;
byte[] buf = new byte[bufSize];
long filePos = 0;
while (filePos < inDataLen)
{
int reqLen = (int)Math.Min(inDataLen - filePos, bufSize);
int trLen = inStream.Read(buf, 0, reqLen);
if (trLen != reqLen)
{
throw new Exception("Incomplete data chunk read from file.");
}
int chunkLen = (trLen + blockSize - 1) / blockSize * blockSize;
for (int i = trLen; i <= chunkLen; i++)
{
buf[i] = 0;
}
for (int pos = 0; pos < chunkLen; pos += blockSize)
{
bsc.crypt(buf, pos);
}
reqLen = (int)Math.Min(outDataLen - filePos, chunkLen);
outStream.Write(buf, 0, reqLen);
filePos += chunkLen;
}
}
