public void Test_Decrypt_DecryptsTwoBlocks()
{
using (var ciphertextStream = new MemoryStream())
using (var key = XChaChaKey.Generate())
{
const int blockLength = 128 * 1024;
var block1 = RandomBytesGenerator.NextBytes(blockLength);
var block2 = RandomBytesGenerator.NextBytes(blockLength);
using (var encryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Encrypt, leaveOpen: true))
{
encryptionStream.Write(block1);
encryptionStream.WriteFinal(block2);
}
ciphertextStream.Position = 0;
using (var decryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Decrypt))
{
var decryptedBlock1 = new byte[blockLength];
var decryptedBlock2 = new byte[blockLength];
var numberOfBytesOutput1 = decryptionStream.Read(decryptedBlock1);
var numberOfBytesOutput2 = decryptionStream.Read(decryptedBlock2);
Assert.Equal(blockLength, numberOfBytesOutput1);
Assert.Equal(block1, decryptedBlock1);
Assert.Equal(blockLength, numberOfBytesOutput2);
Assert.Equal(block2, decryptedBlock2);
}
}
}
public void Test_Decrypt_VerifyEndOfMessage_FalseWhenPartiallyDecrypted()
{
using (var ciphertextStream = new MemoryStream())
using (var key = XChaChaKey.Generate())
{
var plaintext1 = RandomBytesGenerator.NextBytes(1024);
var plaintext2 = RandomBytesGenerator.NextBytes(1024);
using (var encryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Encrypt, leaveOpen: true))
{
encryptionStream.Write(plaintext1);
encryptionStream.WriteFinal(plaintext2);
}
ciphertextStream.Position = 0;
using (var decryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Decrypt))
{
var decryptedPlainText = new byte[plaintext1.Length];
decryptionStream.Read(decryptedPlainText);
Assert.False(decryptionStream.VerifyEndOfMessage());
}
}
}
public void Test_Decrypt_WithInvalidAdditionalData_Fails()
{
using (var ciphertextStream = new MemoryStream())
using (var key = XChaChaKey.Generate())
{
var plaintext = TestConstants.MessageBytes;
var additionalData = Encoding.UTF8.GetBytes("apple");
using (var encryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Encrypt, leaveOpen: true))
{
encryptionStream.WriteFinal(plaintext, additionalData);
}
ciphertextStream.Position = 0;
using (var decryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Decrypt))
{
var decryptedPlainText = new byte[plaintext.Length];
var invalidAdditionalData = Encoding.UTF8.GetBytes("pear");
Action action = () => decryptionStream.Read(decryptedPlainText, invalidAdditionalData);
var exception = Assert.Throws <CryptographicException>(action);
Assert.Equal("block is invalid or corrupt", exception.Message);
Assert.True(decryptedPlainText.All((b) => b == 0));
}
}
}
public void Test_Decrypt_DecryptsBlock_WithAdditionalData()
{
using (var ciphertextStream = new MemoryStream())
using (var key = XChaChaKey.Generate())
{
var plaintext = TestConstants.MessageBytes;
var additionalData = Encoding.UTF8.GetBytes("apple");
using (var encryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Encrypt, leaveOpen: true))
{
encryptionStream.WriteFinal(plaintext, additionalData);
}
ciphertextStream.Position = 0;
using (var decryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Decrypt))
{
var decryptedPlainText = new byte[plaintext.Length];
var numberOfBytesOutput = decryptionStream.Read(decryptedPlainText, additionalData);
Assert.Equal(plaintext.Length, numberOfBytesOutput);
Assert.Equal(plaintext, decryptedPlainText);
}
}
}
public void StandardStream()
{
this.nonBufferedCiphertextStream.Position = 0;
using (var decryptionStream = new XChaChaStream(
nonBufferedCiphertextStream, this.key, EncryptionMode.Decrypt, leaveOpen: true))
{
decryptionStream.Read(this.nonBufferedOutput);
}
}
public void Test_Decrypt_OverReadDecryptionStream_OutputsCorrectNumberOfBytes()
{
using (var ciphertextStream = new MemoryStream())
using (var key = XChaChaKey.Generate())
{
var plaintext = TestConstants.MessageBytes;
using (var encryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Encrypt, leaveOpen: true))
{
encryptionStream.WriteFinal(plaintext);
}
ciphertextStream.Position = 0;
using (var decryptionStream = new XChaChaStream(ciphertextStream, key, EncryptionMode.Decrypt))
{
var decryptedPlainText = new byte[plaintext.Length * 2];
var numberOfBytesOutput = decryptionStream.Read(decryptedPlainText);
Assert.Equal(plaintext.Length, numberOfBytesOutput);
Assert.Equal(plaintext, decryptedPlainText.Take(plaintext.Length));
}
}
}
