public string Decrypt(JweConfig config)
{
byte[] unwrappedKey = RsaEncryption.UnwrapSecretKey(config, Base64Utils.URLDecode(EncryptedKey), "SHA-256");
if (unwrappedKey == null)
{
throw new EncryptionException(String.Format("Failed to unwrap key {0}", EncryptedKey));
}
string encryptionMethod = Header.Enc;
byte[] plaintext;
if (A256GCM.Equals(encryptionMethod))
{
plaintext = AesGcm.Decrypt(unwrappedKey, this);
}
else if (A128CBC_HS256.Equals(encryptionMethod))
{
plaintext = AesCbc.Decrypt(unwrappedKey, this);
}
else
{
throw new EncryptionException(String.Format("Encryption method {0} is not supported", encryptionMethod));
}
return(Encoding.UTF8.GetString(plaintext));
}
public void Decrypt_NullIV_ThrowsArgumentNullException()
{
CbcResult encryptionResult;
using (var provider1 = new AesCbc())
{
encryptionResult = provider1.Encrypt("Hello world");
}
using var provider2 = new AesCbc();
Assert.That(() => provider2.Decrypt(encryptionResult.Cipher, encryptionResult.Key, null), Throws.ArgumentNullException);
}
public void Decrypt_KeyIsNot32Bytes_ThrowsArgumentException()
{
CbcResult encryptionResult;
using (var provider1 = new AesCbc())
{
encryptionResult = provider1.Encrypt("Hello world");
}
using var provider2 = new AesCbc();
Assert.That(() => provider2.Decrypt(encryptionResult.Cipher, new byte[16], encryptionResult.IV), Throws.ArgumentException);
}
public void Decrypt_CipherLengthNotDivisibleBy16_ThrowsArgumentException()
{
CbcResult encryptionResult;
using (var provider1 = new AesCbc())
{
encryptionResult = provider1.Encrypt("Hello world");
}
using var provider2 = new AesCbc();
Assert.That(() => provider2.Decrypt(new byte[new Random().Next(1, 16)], encryptionResult.Key, encryptionResult.IV), Throws.ArgumentException);
}
public void TestChallenge10()
{
var keyStr = "YELLOW SUBMARINE";
var key = System.Text.Encoding.ASCII.GetBytes(keyStr);
var iv = new HexString("0000000000000000");
var data = Convert.FromBase64String(Set2Data.Challenge10Input);
var decrypted = AesCbc.Decrypt(key, iv.Bytes.ToArray(), data);
var actual = System.Text.Encoding.ASCII.GetString(decrypted);
Assert.AreEqual(Set2Data.Challenge10Solution, actual);
}
public void TestDecrypt()
{
var key = new HexString("0102030405060708090A0B0C0D0E0F10");
var iv = new HexString("1112131415161718191A1B1C1D1E1F20");
var data = new HexString("C29B1B0E628232FA5A8F77F88546DF259D8B8B4E73B5D21D9BA1EDB557CAE0A67CA855B59DC1F423A2540EC15377EF70B7750F310C8E40AE68A52E57D478BB60");
var expected = "Hello World, let's try something longer than just one block.";
var decrypted = AesCbc.Decrypt(key.Bytes.ToArray(), iv.Bytes.ToArray(),
data.Bytes.ToArray());
var actual = System.Text.Encoding.ASCII.GetString(decrypted);
Assert.AreEqual(expected, actual);
}
public void TestDecryptOneBlock()
{
var key = new HexString("0102030405060708090A0B0C0D0E0F10");
var iv = new HexString("1112131415161718191A1B1C1D1E1F20");
var data = new HexString("E0A209AC01C9052681925942E0E5EA53");
var expected = "Hello World";
var decrypted = AesCbc.Decrypt(key.Bytes.ToArray(), iv.Bytes.ToArray(),
data.Bytes.ToArray());
var actual = System.Text.Encoding.ASCII.GetString(decrypted);
Assert.AreEqual(expected, actual);
}
public void Decrypt_PlainTextStringEncrypted_ResultMatchesPlaintext(string plainText)
{
CbcResult encryptionResult;
using (var provider1 = new AesCbc())
{
encryptionResult = provider1.Encrypt(plainText);
}
using var provider2 = new AesCbc();
var plainTextResult = provider2.Decrypt(encryptionResult.Cipher, encryptionResult.Key, encryptionResult.IV);
Assert.That(plainTextResult, Is.EqualTo(plainText));
}