// -------------------------------------------------------------------------------
/// <summary>
/// Encrypts and compress the plaintext. (with signature)
/// </summary>
/// <param name="plaintext">The plaintext to be encrypted.</param>
/// <param name="compressStreamWriter">A StreamWriter for the compressing the stream</param>
/// <returns>The encrypted plaintext (-> ciphertext).</returns>
public byte[] Encrypt(byte[] plaintext, CompressStreamWriterDelegate compressStreamWriter)
{
byte[] ret;
try
{
ret = SignedEncrypt(plaintext, compressStreamWriter);
}
catch (Exception ex)
{
throw new Exception("Error within OlympCryptography.Encrypt, see inner exception.", ex);
}
return(ret);
}
// -------------------------------------------------------------------------------
/// <summary>
/// SignedEncrypts the plaintext.
/// </summary>
/// <param name="plaintext">The plaintext to be encrypted.</param>
/// <param name="compressStreamWriter">A StreamWriter for the compressing the stream</param>
/// <returns>The encrypted plaintext (-> ciphertext).</returns>
private byte[] SignedEncrypt(byte[] plaintext, CompressStreamWriterDelegate compressStreamWriter)
{
byte[] ciphertext = null;
MemoryStream memoryStream = new MemoryStream();
byte[] IV = new byte[16];
//Creates the default implementation, which is RijndaelManaged.
SymmetricAlgorithm rijn = SymmetricAlgorithm.Create();
//RNGCryptoServiceProvider is an implementation of a random number generator.
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
// The array is now filled with cryptographically strong random bytes, and none are zero.
rng.GetNonZeroBytes(IV);
// creates a symmetric encryptor object with the specified Key and initialization vector (IV).
ICryptoTransform encryptor = rijn.CreateEncryptor(this.key, IV);
// write the unencrypted initialization vector
BinaryFormatter formatter = new BinaryFormatter();
formatter.Serialize(memoryStream, IV);
// write the digital signature and the DSA parameters
SHA1 sha1Provider = new SHA1CryptoServiceProvider();
DSACryptoServiceProvider dsaProvider = new DSACryptoServiceProvider();
byte[] hashbytes = sha1Provider.ComputeHash(plaintext);
byte[] signature = dsaProvider.SignHash(hashbytes, CryptoConfig.MapNameToOID(SHA1));
formatter.Serialize(memoryStream, signature);
// very important !!!!
// only the public key is serialized -> false as argument to ExportParameters.
formatter.Serialize(memoryStream, dsaProvider.ExportParameters(false));
if (compressStreamWriter != null)
{
// write plaintext into compressed and encrypted stream
MemoryStream compressedStream = new MemoryStream();
using (Stream sw = compressStreamWriter(compressedStream))
{
sw.Write(plaintext, 0, plaintext.Length);
sw.Flush();
sw.Close();
}
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(compressedStream.ToArray(), 0, compressedStream.ToArray().Length);
cryptoStream.Flush();
cryptoStream.Close();
}
}
else
{
// write plaintext into encrypted stream
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plaintext, 0, plaintext.Length);
cryptoStream.Flush();
cryptoStream.Close();
}
}
ciphertext = memoryStream.ToArray();
return ciphertext;
}
// -------------------------------------------------------------------------------
/// <summary>
/// Encrypts and compress the plaintext. (with signature)
/// </summary>
/// <param name="plaintext">The plaintext to be encrypted.</param>
/// <param name="compressStreamWriter">A StreamWriter for the compressing the stream</param>
/// <returns>The encrypted plaintext (-> ciphertext).</returns>
public byte[] Encrypt(byte[] plaintext, CompressStreamWriterDelegate compressStreamWriter)
{
byte[] ret;
try
{
ret = SignedEncrypt(plaintext, compressStreamWriter);
}
catch (Exception ex)
{
throw new Exception("Error within OlympCryptography.Encrypt, see inner exception.", ex);
}
return ret;
}
// -------------------------------------------------------------------------------
/// <summary>
/// SignedEncrypts the plaintext.
/// </summary>
/// <param name="plaintext">The plaintext to be encrypted.</param>
/// <param name="compressStreamWriter">A StreamWriter for the compressing the stream</param>
/// <returns>The encrypted plaintext (-> ciphertext).</returns>
private byte[] SignedEncrypt(byte[] plaintext, CompressStreamWriterDelegate compressStreamWriter)
{
byte[] ciphertext = null;
MemoryStream memoryStream = new MemoryStream();
byte[] IV = new byte[16];
//Creates the default implementation, which is RijndaelManaged.
SymmetricAlgorithm rijn = SymmetricAlgorithm.Create();
//RNGCryptoServiceProvider is an implementation of a random number generator.
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
// The array is now filled with cryptographically strong random bytes, and none are zero.
rng.GetNonZeroBytes(IV);
// creates a symmetric encryptor object with the specified Key and initialization vector (IV).
ICryptoTransform encryptor = rijn.CreateEncryptor(this.key, IV);
// write the unencrypted initialization vector
BinaryFormatter formatter = new BinaryFormatter();
formatter.Serialize(memoryStream, IV);
// write the digital signature and the DSA parameters
SHA1 sha1Provider = new SHA1CryptoServiceProvider();
DSACryptoServiceProvider dsaProvider = new DSACryptoServiceProvider();
byte[] hashbytes = sha1Provider.ComputeHash(plaintext);
byte[] signature = dsaProvider.SignHash(hashbytes, CryptoConfig.MapNameToOID(SHA1));
formatter.Serialize(memoryStream, signature);
// very important !!!!
// only the public key is serialized -> false as argument to ExportParameters.
formatter.Serialize(memoryStream, dsaProvider.ExportParameters(false));
if (compressStreamWriter != null)
{
// write plaintext into compressed and encrypted stream
MemoryStream compressedStream = new MemoryStream();
using (Stream sw = compressStreamWriter(compressedStream))
{
sw.Write(plaintext, 0, plaintext.Length);
sw.Flush();
sw.Close();
}
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(compressedStream.ToArray(), 0, compressedStream.ToArray().Length);
cryptoStream.Flush();
cryptoStream.Close();
}
}
else
{
// write plaintext into encrypted stream
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plaintext, 0, plaintext.Length);
cryptoStream.Flush();
cryptoStream.Close();
}
}
ciphertext = memoryStream.ToArray();
return(ciphertext);
}
