[#1] Define SDK structure

TODO: Вынести маппинг модель -> grpc в отдельный слой

Signed-off-by: Ivan Pchelintsev <i.pchelintsev@yadro.com>

sdk/src/FrostFS.SDK.Cryptography/Helper.cs

@@ -0,0 +1,69 @@
+using System.Buffers.Binary;
+using System.Security.Cryptography;
+using FrostFS.SDK.Cryptography.Tz;
+using Google.Protobuf;
+using Org.BouncyCastle.Crypto.Digests;
+
+namespace FrostFS.SDK.Cryptography;
+
+public static class Helper
+{
+    public const int Sha256HashLength = 32;
+
+    internal static byte[] RIPEMD160(this byte[] value)
+    {
+        var hash = new byte[20];
+        var digest = new RipeMD160Digest();
+        digest.BlockUpdate(value, 0, value.Length);
+        digest.DoFinal(hash, 0);
+        return hash;
+    }
+
+    public static byte[] Sha256(this byte[] value)
+    {
+        using var sha256 = SHA256.Create();
+        return sha256.ComputeHash(value);
+    }
+
+    internal static byte[] Sha256(this byte[] value, int offset, int count)
+    {
+        using var sha256 = SHA256.Create();
+        return sha256.ComputeHash(value, offset, count);
+    }
+
+    internal static byte[] Sha256(this ReadOnlySpan<byte> value)
+    {
+        var buffer = new byte[32];
+        using var sha256 = SHA256.Create();
+        sha256.TryComputeHash(value, buffer, out _);
+        return buffer;
+    }
+
+    public static ByteString Sha256(this IMessage data)
+    {
+        return ByteString.CopyFrom(data.ToByteArray().Sha256());
+    }
+
+    public static ByteString Sha256(this ByteString data)
+    {
+        return ByteString.CopyFrom(data.ToByteArray().Sha256());
+    }
+
+    public static ByteString TzHash(this IMessage data)
+    {
+        return ByteString.CopyFrom(new TzHash().ComputeHash(data.ToByteArray()));
+    }
+
+    public static ByteString TzHash(this ByteString data)
+    {
+        return ByteString.CopyFrom(new TzHash().ComputeHash(data.ToByteArray()));
+    }
+
+    
+
+    public static ulong Murmur64(this byte[] value, uint seed)
+    {
+        using var murmur = new Murmur3_128(seed);
+        return BinaryPrimitives.ReadUInt64LittleEndian(murmur.ComputeHash(value));
+    }
+}