More hashing services and HMAC services

SystemExtensions.NetStandard.Security/Hashing/BaseHashingService.cs

@@ -0,0 +1,63 @@
+using System.IO;
+using System.Security.Cryptography;
+using System.Threading.Tasks;
+
+namespace System.Security.Hashing;
+public abstract class BaseHashingService<T>
+    where T : HashAlgorithm
+{
+    protected abstract T GetHashAlgorithm();
+
+    public async Task<string> Hash(string raw)
+    {
+        using var rawStream = BytesToStream(StringToBytes(raw));
+        using var hashedStream = await this.HashInternal(rawStream).ConfigureAwait(false);
+        return StreamToString(hashedStream);
+    }
+    public async Task<byte[]> Hash(byte[] raw)
+    {
+        using var rawStream = BytesToStream(raw);
+        using var hashedStream = await this.HashInternal(rawStream).ConfigureAwait(false);
+        return StreamToBytes(hashedStream);
+    }
+    public async Task<Stream> Hash(Stream raw)
+    {
+        return await this.HashInternal(raw);
+    }
+
+    private static byte[] StreamToBytes(Stream value)
+    {
+        value.Position = 0;
+        var buffer = new byte[1024];
+        using var ms = new MemoryStream();
+        var read = -1;
+        do
+        {
+            read = value.Read(buffer, 0, buffer.Length);
+            ms.Write(buffer, 0, read);
+        } while (read > 0);
+        return ms.ToArray();
+    }
+    private static string StreamToString(Stream value)
+    {
+        return Convert.ToBase64String(StreamToBytes(value));
+    }
+    private static byte[] StringToBytes(string value)
+    {
+        return Convert.FromBase64String(value);
+    }
+    private static Stream BytesToStream(byte[] value)
+    {
+        return new MemoryStream(value);
+    }
+    private async Task<Stream> HashInternal(Stream raw)
+    {
+        if (raw is null)
+        {
+            throw new ArgumentNullException(nameof(raw));
+        }
+
+        using var algo = this.GetHashAlgorithm();
+        return await Task.Run(() => new MemoryStream(algo.ComputeHash(raw)));
+    }
+}