public static ReadOnlySpan <byte> Hash256(ReadOnlySpan <byte> data)
{
using (var sha = new SHA256Managed())
{
Span <byte> result = stackalloc byte[32];
sha.TryComputeHash(data, result, out _);
sha.TryComputeHash(result, result, out _);
return(result.ToArray());
}
}
public static ReadOnlySpan <byte> DoubleSha256(ReadOnlySpan <byte> data)
{
using var sha = new SHA256Managed();
Span <byte> result = new byte[32];
if (!sha.TryComputeHash(data, result, out _) || !sha.TryComputeHash(result, result, out _))
{
ThrowHashGeneratorException($"Failed to perform {nameof(DoubleSha256)}");
}
return(result);
}
public static Span <byte> SHA256d(this ReadOnlySpan <byte> data)
{
using (var sha = new SHA256Managed())
{
//internally this is copied to the destination so its ok to reuse the destination twice
//https://github.com/dotnet/corefx/blob/57608f6a5cfeadf338dc6c5d0300147b39168012/src/System.Security.Cryptography.Primitives/src/System/Security/Cryptography/HashAlgorithm.cs#L244
var h1 = new Span <byte>(new byte[sha.HashSize / 8]);
sha.TryComputeHash(data, h1, out int _);
sha.TryComputeHash(h1, h1, out int _);
return(h1);
}
}
public static UInt256 DoubleSha256AsUInt256(ReadOnlySpan <byte> data)
{
using var sha = new SHA256Managed();
Span <byte> result = stackalloc byte[32];
if (!sha.TryComputeHash(data, result, out _))
{
throw new HashGeneratorException($"Failed to perform {nameof(DoubleSha256AsUInt256)}");
}
if (!sha.TryComputeHash(result, result, out _))
{
throw new HashGeneratorException($"Failed to perform {nameof(DoubleSha256AsUInt256)}");
}
return(new UInt256(result));
}
public static int HashSHA256(ReadOnlySpan <byte> src, Span <byte> dest)
{
SHA256 sha = new SHA256Managed();
if (sha.TryComputeHash(src, dest, out int ret) == false)
{
throw new ApplicationException("TryComputeHash error.");
}
return(ret);
}
internal string CreateUserHash(HttpContext context)
{
ReadOnlySpan <byte> saltSpan = m_saltProvider.GetSalt();
using IMemoryOwner <byte> uidMemoryOwner = MemoryPool <byte> .Shared.Rent(m_maxIdentitySize + saltSpan.Length);
Span <byte> uidSpan = uidMemoryOwner.Memory.Span;
uidSpan.Fill(0);
int identityBytesWritten = -1;
foreach (IUserIdentityProvider provider in m_userIdentityProviders)
{
if (provider.TryWriteBytes(context, uidSpan.Slice(0, provider.MaxBytesInIdentity), out identityBytesWritten))
{
break;
}
}
if (identityBytesWritten <= 0)
{
return(string.Empty);
}
saltSpan.CopyTo(uidSpan.Slice(identityBytesWritten));
using IMemoryOwner <byte> hashMemoryOwner = MemoryPool <byte> .Shared.Rent(HashSize);
Span <byte> hashSpan = hashMemoryOwner.Memory.Span;
#if NETCOREAPP3_1
using HashAlgorithm hashAlgorithm = new SHA256Managed(); // need to have new instance each time since its not thread-safe
if (!hashAlgorithm.TryComputeHash(uidSpan, hashSpan, out _))
{
return(string.Empty);
}
return(BitConverter.ToString(hashSpan.ToArray()).Replace("-", ""));
#else
SHA256.HashData(uidSpan, hashSpan);
return(Convert.ToHexString(hashSpan));
#endif
}
public static Boolean Sha256(ReadOnlySpan <Byte> data, Span <Byte> destination, out Int32 written)
{
using SHA256 sha256 = new SHA256Managed();
return(sha256.TryComputeHash(data, destination, out written));
}
