Exemple #1
0
        public static MemoryStream EncryptMemory(string inFile, MemoryStream mout, string password, CryptoProgressCallBack callback)
        {
            //		string vol=GetDriveVolumeProperties("C");
            //		MessageBox.Show(vol);


            using (FileStream fin = File.OpenRead(inFile))
            {
                long   lSize = fin.Length;            // the size of the input file for storing
                int    size  = (int)lSize;            // the size of the input file for progress
                byte[] bytes = new byte[BUFFER_SIZE]; // the buffer
                int    read  = -1;                    // the amount of bytes read from the input file
                int    value = 0;                     // the amount overall read from the input file for progress

                // generate IV and Salt
                byte[] IV   = GenerateRandomBytes(16);
                byte[] salt = GenerateRandomBytes(16);

                // create the crypting object
                SymmetricAlgorithm sma = CryptoHelp.CreateRijndael(password, salt);
                sma.IV = IV;

                // write the IV and salt to the beginning of the file


                mout.Write(IV, 0, IV.Length);
                mout.Write(salt, 0, salt.Length);


                // create the hashing and crypto streams
                HashAlgorithm hasher = SHA256.Create();
                using (CryptoStream cout = new CryptoStream(mout, sma.CreateEncryptor(), CryptoStreamMode.Write),
                       chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
                {
                    // write the size of the file to the output file
                    BinaryWriter bw = new BinaryWriter(cout);
                    bw.Write(lSize);

                    // write the file cryptor tag to the file
                    bw.Write(FC_TAG);

                    //		BinaryWriter mbw = new BinaryWriter(mout);
                    //		mbw.Write(lSize);

                    //		mbw.Write(FC_TAG);

                    // read and the write the bytes to the crypto stream in BUFFER_SIZEd chunks
                    while ((read = fin.Read(bytes, 0, bytes.Length)) != 0)
                    {
                        cout.Write(bytes, 0, read);
                        //		mout.Write(bytes,0,read);
                        chash.Write(bytes, 0, read);
                        value += read;
                        if (callback != null)
                        {
                            callback(0, size, value);
                        }
                    }
                    // flush and close the hashing object
                    chash.Flush();
                    chash.Close();

                    // read the hash
                    byte[] hash = hasher.Hash;

                    // write the hash to the end of the file
                    cout.Write(hash, 0, hash.Length);
                    //		mout.Write(hash,0,hash.Length);


                    // flush and close the cryptostream
                    cout.Flush();
                    cout.FlushFinalBlock();

                    //		cout.Close();
                    //		mout.Flush();
                    //		mout.Close();

                    return(mout);
                }
            }
        }
Exemple #2
0
        public static void DecryptMemory(MemoryStream fin, string outFile, string password) //, CryptoProgressCallBack callback)
        {
            // NOTE:  The encrypting algo was so much easier...

            // create and open the file streams
            using (FileStream fout = File.OpenWrite(outFile))
            {
                int    size     = (int)fin.Length;       // the size of the file for progress notification
                byte[] bytes    = new byte[BUFFER_SIZE]; // byte buffer
                int    read     = -1;                    // the amount of bytes read from the stream
                int    value    = 0;
                int    outValue = 0;                     // the amount of bytes written out

                // read off the IV and Salt
                byte[] IV = new byte[16];
                fin.Read(IV, 0, 16);
                byte[] salt = new byte[16];
                fin.Read(salt, 0, 16);

                // create the crypting stream
                SymmetricAlgorithm sma = CryptoHelp.CreateRijndael(password, salt);
                sma.IV = IV;

                value = 32;      // the value for the progress
                long lSize = -1; // the size stored in the input stream

                // create the hashing object, so that we can verify the file
                HashAlgorithm hasher = SHA256.Create();

                // create the cryptostreams that will process the file
                using (CryptoStream cin = new CryptoStream(fin, sma.CreateDecryptor(), CryptoStreamMode.Read),
                       chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
                {
                    // read size from file
                    BinaryReader br = new BinaryReader(cin);
                    lSize = br.ReadInt64();
                    ulong tag = br.ReadUInt64();

                    if (FC_TAG != tag)
                    {
                        throw new CryptoHelpException("File Corrupted!");
                    }

                    //determine number of reads to process on the file
                    long numReads = lSize / BUFFER_SIZE;

                    // determine what is left of the file, after numReads
                    long slack = (long)lSize % BUFFER_SIZE;

                    // read the buffer_sized chunks
                    for (int i = 0; i < numReads; ++i)
                    {
                        read = cin.Read(bytes, 0, bytes.Length);
                        fout.Write(bytes, 0, read);
                        chash.Write(bytes, 0, read);
                        value    += read;
                        outValue += read;
                        //					callback(0,size,value);
                    }

                    // now read the slack
                    if (slack > 0)
                    {
                        read = cin.Read(bytes, 0, (int)slack);
                        fout.Write(bytes, 0, read);
                        chash.Write(bytes, 0, read);
                        value    += read;
                        outValue += read;
                        //					callback(0,size,value);
                    }
                    // flush and close the hashing stream
                    chash.Flush();
                    chash.Close();

                    // flush and close the output file
                    fout.Flush();
                    fout.Close();

                    // read the current hash value
                    byte[] curHash = hasher.Hash;

                    // get and compare the current and old hash values
                    byte[] oldHash = new byte[hasher.HashSize / 8];
                    read = cin.Read(oldHash, 0, oldHash.Length);
                    if ((oldHash.Length != read) || (!CheckByteArrays(oldHash, curHash)))
                    {
                        throw new CryptoHelpException("File Corrupted!");
                    }
                }

                // make sure the written and stored size are equal
                if (outValue != lSize)
                {
                    throw new CryptoHelpException("File Sizes don't match!");
                }
            }

            #endregion
        }