Documentation pour le cryptage AES 256 Bouncy Castle en .Net?

Question

Je suis en train de mettre en œuvre la bibliothèque de chiffrement Bouncy Castle dans un projet .Net, mais je suis de ne pas trouver beaucoup de documents dans le domaine .Net. La structure de classe / méthode est même pas proche des exemples liés à Java amples.

Quelqu'un at-il de bons exemples .Net pour cela?

Merci.

Answer 1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


using System.IO;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Modes;
using Org.BouncyCastle.Crypto.Paddings;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities.Encoders;

namespace BouncyCastleProject
{
    public class DesExample
    {
        // Encrypting or decrypting ?
        private bool encrypt = true;

        // To hold the initialised DESede cipher
        private PaddedBufferedBlockCipher cipher = null;

        // The input stream of bytes to be processed for encryption
        private Stream inStr = null;

        // The output stream of bytes to be procssed
        private Stream outStr = null;

        // The key
        private byte[] key = null;

        /*
        * start the application
        */
        //////public static void Main(string[] args)
        //////{
        //////    bool encrypt = true;
        //////    string infile = null;
        //////    string outfile = null;
        //////    string keyfile = null;

        //////    if (args.Length < 2)
        //////    {
        //////        //    Console.Error.WriteLine("Usage: java " + typeof(DesExample).Name + " infile outfile [keyfile]");
        //////        Console.Error.WriteLine("Usage: " + typeof(DesExample).Name + " infile outfile [keyfile]");
        //////        Environment.Exit(1);
        //////    }

        //////    keyfile = "deskey.dat";
        //////    infile = args[0];
        //////    outfile = args[1];

        //////    if (args.Length > 2)
        //////    {
        //////        encrypt = false;
        //////        keyfile = args[2];
        //////    }

        //////    DesExample de = new DesExample(infile, outfile, keyfile, encrypt);
        //////    de.process();
        //////}

        // Default constructor, used for the usage message
        public DesExample()
        {
        }

        /*
        * Constructor, that takes the arguments appropriate for
        * processing the command line directives.
        */
        public DesExample(
            string infile,
            string outfile,
            string keyfile,
            bool encrypt)
        {
            /* 
            * First, determine that infile & keyfile exist as appropriate.
            *
            * This will also create the BufferedInputStream as required
            * for reading the input file.  All input files are treated
            * as if they are binary, even if they contain text, it's the
            * bytes that are encrypted.
            */
            this.encrypt = encrypt;
            try
            {
                inStr = File.OpenRead(infile);
            }
            catch (FileNotFoundException)
            {
                //Console.Error.WriteLine("Input file not found [" + infile + "]");
                Environment.Exit(1);
            }

            try
            {
                outStr = File.Create(outfile);
            }
            catch (IOException)
            {
                //Console.Error.WriteLine("Output file not created [" + outfile + "]");
                Environment.Exit(1);
            }

            if (encrypt)
            {
                try
                {
                    /*
                    * The process of creating a new key requires a 
                    * number of steps.
                    *
                    * First, create the parameters for the key generator
                    * which are a secure random number generator, and
                    * the length of the key (in bits).
                    */
                    SecureRandom sr = new SecureRandom();

                    KeyGenerationParameters kgp = new KeyGenerationParameters(
                        sr, 
                        DesEdeParameters.DesEdeKeyLength * 8);

                    /*
                    * Second, initialise the key generator with the parameters
                    */

                    DesEdeKeyGenerator kg = new DesEdeKeyGenerator();
                    kg.Init(kgp);

                    /*
                    * Third, and finally, generate the key
                    */
                    key = kg.GenerateKey();

                    /*
                    * We can now output the key to the file, but first
                    * hex Encode the key so that we can have a look
                    * at it with a text editor if we so desire
                    */
                    Stream keystream = File.Create(keyfile);
                    byte[] keyhex = Hex.Encode(key);
                    keystream.Write(keyhex, 0, keyhex.Length);
                    keystream.Flush();
                    keystream.Close();
                }
                catch (IOException)
                {
                    //Console.Error.WriteLine("Could not decryption create key file [" + keyfile + "]");
                    Environment.Exit(1);
                }
            }
            else
            {
                try
                {
                    // TODO This block is a bit dodgy

                    // read the key, and Decode from hex encoding
                    Stream keystream = File.OpenRead(keyfile);
                    //     int len = keystream.available();
                    int len = (int)keystream.Length;
                    byte[] keyhex = new byte[len];
                    keystream.Read(keyhex, 0, len);
                    key = Hex.Decode(keyhex);
                }
                catch (IOException)
                {
                    //Console.Error.WriteLine("Decryption key file not found, or not valid [" + keyfile + "]");
                    Environment.Exit(1);
                }
            }
        }

        public void process()
        {
            /* 
            * Setup the DESede cipher engine, create a PaddedBufferedBlockCipher
            * in CBC mode.
            */
            cipher = new PaddedBufferedBlockCipher(
                new CbcBlockCipher(new DesEdeEngine()));

            /*
            * The input and output streams are currently set up
            * appropriately, and the key bytes are ready to be
            * used.
            *
            */

            if (encrypt)
            {
                performEncrypt(key);
            }
            else
            {
                performDecrypt(key);
            }

            // after processing clean up the files
            try
            {
                inStr.Close();
                outStr.Flush();
                outStr.Close();
            }
            catch (IOException)
            {
            }
        }

        /*
        * This method performs all the encryption and writes
        * the cipher text to the buffered output stream created
        * previously.
        */
        private void performEncrypt(byte[] key)
        {
            // initialise the cipher with the key bytes, for encryption
            cipher.Init(true, new KeyParameter(key));

            /*
            * Create some temporary byte arrays for use in
            * encryption, make them a reasonable size so that
            * we don't spend forever reading small chunks from
            * a file.
            *
            * There is no particular reason for using getBlockSize()
            * to determine the size of the input chunk.  It just
            * was a convenient number for the example.  
            */
            // int inBlockSize = cipher.getBlockSize() * 5;
            int inBlockSize = 47;
            int outBlockSize = cipher.GetOutputSize(inBlockSize);

            byte[] inblock = new byte[inBlockSize];
            byte[] outblock = new byte[outBlockSize];

            /* 
            * now, read the file, and output the chunks
            */
            try
            {
                int inL;
                int outL;
                byte[] rv = null;
                while ((inL = inStr.Read(inblock, 0, inBlockSize)) > 0)
                {
                    outL = cipher.ProcessBytes(inblock, 0, inL, outblock, 0);

                    /*
                    * Before we write anything out, we need to make sure
                    * that we've got something to write out. 
                    */
                    if (outL > 0)
                    {
                        rv = Hex.Encode(outblock, 0, outL);
                        outStr.Write(rv, 0, rv.Length);
                        outStr.WriteByte((byte)'\n');
                    }
                }

                try
                {
                    /*
                    * Now, process the bytes that are still buffered
                    * within the cipher.
                    */
                    outL = cipher.DoFinal(outblock, 0);
                    if (outL > 0)
                    {
                        rv = Hex.Encode(outblock, 0, outL);
                        outStr.Write(rv, 0, rv.Length);
                        outStr.WriteByte((byte)'\n');
                    }
                }
                catch (CryptoException)
                {

                }
            }
            catch (IOException ioeread)
            {
               // Console.Error.WriteLine(ioeread.StackTrace);
            }
        }

        /*
        * This method performs all the decryption and writes
        * the plain text to the buffered output stream created
        * previously.
        */
        private void performDecrypt(byte[] key)
        {
            // initialise the cipher for decryption
            cipher.Init(false, new KeyParameter(key));

            /* 
            * As the decryption is from our preformatted file,
            * and we know that it's a hex encoded format, then
            * we wrap the InputStream with a BufferedReader
            * so that we can read it easily.
            */
            //   BufferedReader br = new BufferedReader(new StreamReader(inStr));
            StreamReader br = new StreamReader(inStr); // 'inStr' already buffered

            /* 
            * now, read the file, and output the chunks
            */
            try
            {
                int outL;
                byte[] inblock = null;
                byte[] outblock = null;
                string rv = null;
                while ((rv = br.ReadLine()) != null)
                {
                    inblock = Hex.Decode(rv);
                    outblock = new byte[cipher.GetOutputSize(inblock.Length)];

                    outL = cipher.ProcessBytes(inblock, 0, inblock.Length, outblock, 0);
                    /*
                    * Before we write anything out, we need to make sure
                    * that we've got something to write out. 
                    */
                    if (outL > 0)
                    {
                        outStr.Write(outblock, 0, outL);
                    }
                }

                try
                {
                    /*
                    * Now, process the bytes that are still buffered
                    * within the cipher.
                    */
                    outL = cipher.DoFinal(outblock, 0);
                    if (outL > 0)
                    {
                        outStr.Write(outblock, 0, outL);
                    }
                }
                catch (CryptoException)
                {

                }
            }
            catch (IOException ioeread)
            {
                //Console.Error.WriteLine(ioeread.StackTrace);
            }
        }

    }
}

Answer 2

Les classes C # est presque identique aux classes Java pour moi. Une différence est que les interfaces en C # suivent la convention .NET et commencent par la lettre « I ». Par exemple, IBlockCipher est l'analogue C # pour la BlockCipher Java, et correspond à ICipherParameters à Java CipherParameters. J'attendre les exemples Java de traduire presque parfaitement dans des exemples C #. Yat-il un exemple java particulier que vous rencontrez des problèmes pour traduire C #?