/// <summary>
/// Decrypts a secret using the configured <c>SymmetricAlgorithm</c>.
/// <seealso cref="ISymmetricCryptoProvider.Decrypt"/>
/// </summary>
/// <param name="ciphertext"><para>The cipher text to be decrypted.</para></param>
/// <returns><para>The resulting plain text. It is the responsibility of the caller to clear the returned byte array
/// when finished.</para></returns>
/// <seealso cref="ISymmetricCryptoProvider.Decrypt"/>
public byte[] Decrypt(byte[] ciphertext)
{
if (ciphertext == null)
{
throw new ArgumentNullException("ciphertext");
}
if (ciphertext.Length == 0)
{
throw new ArgumentException(Resources.ExceptionByteArrayValueMustBeGreaterThanZeroBytes, "ciphertext");
}
byte[] output = null;
try
{
using (SymmetricCryptographer crypto = new SymmetricCryptographer(algorithmType, key))
{
output = crypto.Decrypt(ciphertext);
}
}
catch (Exception e)
{
InstrumentationProvider.FireCyptographicOperationFailed(Resources.DecryptionFailed, e);
throw;
}
InstrumentationProvider.FireSymmetricDecryptionPerformed();
return(output);
}
/// <summary>
/// Decrypts a secret using the configured <c>SymmetricAlgorithm</c>.
/// <seealso cref="ISymmetricCryptoProvider.Decrypt"/>
/// </summary>
/// <param name="ciphertext"><para>The cipher text for which you want to decrypt.</para></param>
/// <returns><para>The resulting plain text.</para></returns>
/// <seealso cref="ISymmetricCryptoProvider.Decrypt"/>
public byte[] Decrypt(byte[] ciphertext)
{
ArgumentValidation.CheckForNullReference(ciphertext, "encryptedText");
ArgumentValidation.CheckForZeroBytes(ciphertext, "encryptedText");
byte[] output = null;
SymmetricAlgorithmProviderData data = GetSymmetricAlgorithmProviderDataFromCursor();
SymmetricCryptographer crypto = new SymmetricCryptographer(data.AlgorithmType, data.Key);
output = crypto.Decrypt(ciphertext);
SecurityCryptoSymmetricDecryptionEvent.Fire(string.Empty);
return(output);
}
public void EncryptAndDecryptWithType()
{
byte[] key = new byte[16];
CryptographyUtility.GetRandomBytes(key);
ProtectedKey protectedKey = ProtectedKey.CreateFromPlaintextKey(key, DataProtectionScope.LocalMachine);
SymmetricCryptographer symm = new SymmetricCryptographer(typeof(RijndaelManaged), protectedKey);
byte[] plainText = new byte[12];
CryptographyUtility.GetRandomBytes(plainText);
byte[] cipherText = symm.Encrypt(plainText);
Assert.IsFalse(CryptographyUtility.CompareBytes(cipherText, plainText));
byte[] decryptedText = symm.Decrypt(cipherText);
Assert.IsTrue(CryptographyUtility.CompareBytes(plainText, decryptedText));
}
/// <summary>
/// Decrypts a secret using the configured <c>SymmetricAlgorithm</c>.
/// <seealso cref="ISymmetricCryptoProvider.Decrypt"/>
/// </summary>
/// <param name="ciphertext"><para>The cipher text to be decrypted.</para></param>
/// <returns><para>The resulting plain text. It is the responsibility of the caller to clear the returned byte array
/// when finished.</para></returns>
/// <seealso cref="ISymmetricCryptoProvider.Decrypt"/>
public byte[] Decrypt(byte[] ciphertext)
{
if (ciphertext == null) throw new ArgumentNullException("ciphertext");
if (ciphertext.Length == 0) throw new ArgumentException(Resources.ExceptionByteArrayValueMustBeGreaterThanZeroBytes, "ciphertext");
byte[] output = null;
try
{
using (SymmetricCryptographer crypto = new SymmetricCryptographer(algorithmType, key))
{
output = crypto.Decrypt(ciphertext);
}
}
catch (Exception e)
{
InstrumentationProvider.FireCyptographicOperationFailed(Resources.DecryptionFailed, e);
throw;
}
InstrumentationProvider.FireSymmetricDecryptionPerformed();
return output;
}
