public DatabaseProjectRepository(IObjectSerializationProvider objectSerializationProvider, ISymmetricEncryptionProvider encryptionProvider)
{
this.objectSerializationProvider = objectSerializationProvider;
this.encryptionProvider = encryptionProvider;
encryptionInfo = new EncryptionInfo();
encryptionInfo.KeySize = 256;
encryptionInfo.HashAlgorithm = Resources.EncryptionHashValue;
encryptionInfo.PassPhrase = Resources.EncryptionPassPhrase;
encryptionInfo.SaltValue = Resources.EncryptionSaltValue;
encryptionInfo.Iterations = 5;
encryptionInfo.InitVector = Resources.EncryptionInitVector;
}
public string Encrypt(string plainText, EncryptionInfo info)
{
// Convert strings into byte arrays.
// Let us assume that strings only contain ASCII codes.
// If strings include Unicode characters, use Unicode, UTF7, or UTF8
// encoding.
byte[] initVectorBytes = Encoding.ASCII.GetBytes(info.InitVector);
byte[] saltValueBytes = Encoding.ASCII.GetBytes(info.SaltValue);
// Convert our plaintext into a byte array.
// Let us assume that plaintext contains UTF8-encoded characters.
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
// First, we must create a password, from which the key will be derived.
// This password will be generated from the specified passphrase and
// salt value. The password will be created using the specified hash
// algorithm. Password creation can be done in several iterations.
PasswordDeriveBytes password = new PasswordDeriveBytes(
info.PassPhrase,
saltValueBytes,
info.HashAlgorithm,
info.Iterations);
// Use the password to generate pseudo-random bytes for the encryption
// key. Specify the size of the key in bytes (instead of bits).
byte[] keyBytes = password.GetBytes(info.KeySize / 8);
// Create uninitialized Rijndael encryption object.
RijndaelManaged symmetricKey = new RijndaelManaged();
// It is reasonable to set encryption mode to Cipher Block Chaining
// (CBC). Use default options for other symmetric key parameters.
symmetricKey.Mode = CipherMode.CBC;
// Generate encryptor from the existing key bytes and initialization
// vector. Key size will be defined based on the number of the key
// bytes.
ICryptoTransform encryptor = symmetricKey.CreateEncryptor(
keyBytes,
initVectorBytes);
// Define memory stream which will be used to hold encrypted data.
MemoryStream memoryStream = new MemoryStream();
// Define cryptographic stream (always use Write mode for encryption).
CryptoStream cryptoStream = new CryptoStream(memoryStream,
encryptor,
CryptoStreamMode.Write);
// Start encrypting.
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
// Finish encrypting.
cryptoStream.FlushFinalBlock();
// Convert our encrypted data from a memory stream into a byte array.
byte[] cipherTextBytes = memoryStream.ToArray();
// Close both streams.
memoryStream.Close();
cryptoStream.Close();
// Convert encrypted data into a base64-encoded string.
string cipherText = Convert.ToBase64String(cipherTextBytes);
// Return encrypted string.
return cipherText;
}
public string Decrypt(string cipherText, EncryptionInfo info)
{
// Convert strings defining encryption key characteristics into byte
// arrays. Let us assume that strings only contain ASCII codes.
// If strings include Unicode characters, use Unicode, UTF7, or UTF8
// encoding.
byte[] initVectorBytes = Encoding.ASCII.GetBytes(info.InitVector);
byte[] saltValueBytes = Encoding.ASCII.GetBytes(info.SaltValue);
// Convert our ciphertext into a byte array.
byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
// First, we must create a password, from which the key will be
// derived. This password will be generated from the specified
// passphrase and salt value. The password will be created using
// the specified hash algorithm. Password creation can be done in
// several iterations.
PasswordDeriveBytes password = new PasswordDeriveBytes(
info.PassPhrase,
saltValueBytes,
info.HashAlgorithm,
info.Iterations);
// Use the password to generate pseudo-random bytes for the encryption
// key. Specify the size of the key in bytes (instead of bits).
byte[] keyBytes = password.GetBytes(info.KeySize / 8);
// Create uninitialized Rijndael encryption object.
RijndaelManaged symmetricKey = new RijndaelManaged();
// It is reasonable to set encryption mode to Cipher Block Chaining
// (CBC). Use default options for other symmetric key parameters.
symmetricKey.Mode = CipherMode.CBC;
// Generate decryptor from the existing key bytes and initialization
// vector. Key size will be defined based on the number of the key
// bytes.
ICryptoTransform decryptor = symmetricKey.CreateDecryptor(
keyBytes,
initVectorBytes);
// Define memory stream which will be used to hold encrypted data.
MemoryStream memoryStream = new MemoryStream(cipherTextBytes);
// Define cryptographic stream (always use Read mode for encryption).
CryptoStream cryptoStream = new CryptoStream(memoryStream,
decryptor,
CryptoStreamMode.Read);
// Since at this point we don't know what the size of decrypted data
// will be, allocate the buffer long enough to hold ciphertext;
// plaintext is never longer than ciphertext.
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
// Start decrypting.
int decryptedByteCount = cryptoStream.Read(plainTextBytes,
0,
plainTextBytes.Length);
// Close both streams.
memoryStream.Close();
cryptoStream.Close();
// Convert decrypted data into a string.
// Let us assume that the original plaintext string was UTF8-encoded.
string plainText = Encoding.UTF8.GetString(plainTextBytes,
0,
decryptedByteCount);
// Return decrypted string.
return plainText;
}