public void HashByCryptoStream()
{
var provider = WinRTCrypto.HashAlgorithmProvider.OpenAlgorithm(HashAlgorithm.Sha1);
var hasher = provider.CreateHash();
using (var stream = new PCLCrypto.CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
{
stream.Write(this.data, 0, this.data.Length);
}
Assert.Equal(this.dataHash, Convert.ToBase64String(hasher.GetValueAndReset()));
}
public void HashByCryptoStream()
{
IHashAlgorithmProvider?provider = WinRTCrypto.HashAlgorithmProvider.OpenAlgorithm(HashAlgorithm.Sha1);
CryptographicHash? hasher = provider.CreateHash();
using (var stream = new PCLCrypto.CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
{
stream.Write(this.data, 0, this.data.Length);
}
Assert.Equal(this.dataHash, Convert.ToBase64String(hasher.GetValueAndReset()));
}
public void HashByCryptoStream()
{
var algorithm = WinRTCrypto.MacAlgorithmProvider.OpenAlgorithm(MacAlgorithm.HmacSha1);
var hasher = algorithm.CreateHash(this.keyMaterial);
using (var stream = new PCLCrypto.CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
{
stream.Write(this.data, 0, this.data.Length);
}
Assert.Equal(this.macBase64, Convert.ToBase64String(hasher.GetValueAndReset()));
}
// Returned array is guaranteed to be non-null and safe to index into the first 4
// bytes using pointer arithmetic.
private static byte[] Hash(byte[] value)
{
byte[] hash;
using (var hasher = HashAlgorithmProvider.OpenAlgorithm(HashAlgorithm.Sha256).CreateHash())
{
using (var stream = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
{
stream.Write(value, 0, value.Length - SumLength);
}
var intermediateHash = hasher.GetValueAndReset();
hasher.Append(intermediateHash);
hash = hasher.GetValueAndReset();
}
if (hash.Length != Sha256Hash.Length || hash.Length < SumLength)
throw new Exception($"Double-SHA256 result has improper length {hash.Length}");
return hash;
}
public void HashByCryptoStream()
{
var algorithm = WinRTCrypto.MacAlgorithmProvider.OpenAlgorithm(MacAlgorithm.HmacSha1);
var hasher = algorithm.CreateHash(this.keyMaterial);
using (var stream = new PCLCrypto.CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
{
stream.Write(this.data, 0, this.data.Length);
}
Assert.Equal(this.macBase64, Convert.ToBase64String(hasher.GetValueAndReset()));
}
/// <summary>
/// Creates a CryptoStream chain of transforms.
/// </summary>
/// <param name="stream">The ultimate stream to be read from or written to.</param>
/// <param name="cryptoStreamMode">Whether to prepare for read or write operations to trigger the operations.</param>
/// <param name="transforms">The transforms to apply.</param>
/// <returns>The start of the chain of CryptoStreams.</returns>
private static CryptoStream Chain(Stream stream, CryptoStreamMode cryptoStreamMode, params ICryptoTransform[] transforms)
{
Requires.NotNull(stream, "stream");
Requires.NotNullOrEmpty(transforms, "transforms");
if (cryptoStreamMode == CryptoStreamMode.Write)
{
// Arrange the transforming streams in this fashion:
// T1 -> T2 -> stream
// Which means we need recursion to define:
// CS1(CS2(stream))
using (IEnumerator<ICryptoTransform> transformsEnumerator = transforms.Cast<ICryptoTransform>().GetEnumerator())
{
return (CryptoStream)ChainWrite(stream, transformsEnumerator);
}
}
else
{
// Arrange the transforming streams in this fashion:
// stream -> T1 -> T2
// Which means we need iteration to define:
// CS2(CS1(stream))
foreach (var transform in transforms)
{
stream = new CryptoStream(stream, transform, CryptoStreamMode.Read);
}
return (CryptoStream)stream;
}
}
/// <summary>
/// Symmetrically encrypts a stream.
/// </summary>
/// <param name="cryptoProvider">The crypto provider.</param>
/// <param name="plaintext">The stream of plaintext to encrypt.</param>
/// <param name="ciphertext">The stream to receive the ciphertext.</param>
/// <param name="encryptionVariables">An optional key and IV to use. May be <c>null</c> to use randomly generated values.</param>
/// <param name="cancellationToken">A cancellation token.</param>
/// <returns>
/// A task that completes when encryption has completed, whose result is the key and IV to use to decrypt the ciphertext.
/// </returns>
public static async Task<SymmetricEncryptionVariables> EncryptAsync(this CryptoSettings cryptoProvider, Stream plaintext, Stream ciphertext, SymmetricEncryptionVariables encryptionVariables = null, CancellationToken cancellationToken = default(CancellationToken))
{
Requires.NotNull(plaintext, "plaintext");
Requires.NotNull(ciphertext, "ciphertext");
encryptionVariables = ThisOrNewEncryptionVariables(cryptoProvider, encryptionVariables);
var key = CryptoSettings.SymmetricAlgorithm.CreateSymmetricKey(encryptionVariables.Key);
using (var encryptor = WinRTCrypto.CryptographicEngine.CreateEncryptor(key, encryptionVariables.IV))
{
var cryptoStream = new CryptoStream(ciphertext, encryptor, CryptoStreamMode.Write);
await plaintext.CopyToAsync(cryptoStream, 4096, cancellationToken).ConfigureAwait(false);
cryptoStream.FlushFinalBlock();
}
return encryptionVariables;
}
