feat: add Cell.Hash()

Author: justdmitry

TonLibDotNet.Tests/Cells/CellTests.cs

@@ -25,5 +25,19 @@ public void BeginReadOk(string hexData, bool augmented, string expectedBinData)
 
             Assert.Equal(expected, actual);
         }
+
+        [Fact]
+        public void HashOk()
+        {
+            // sample data from TestBOCBomb at https://github.com/xssnick/tonutils-go/blob/619c2aa1f6b992997bf322f8f9bfc4ae036a5181/tvm/cell/cell_test.go#L206-L215
+            var boc_base64 = "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";
+            var hash_hex = "EC89185485A679715A615BCA264BF01B4CB619BD28D9E17FF73D05CF5E01C0E0";
+
+            var boc = Boc.ParseFromBase64(boc_base64);
+            var rootCell = boc.RootCells[0];
+            var hash = rootCell.Hash();
+
+            Assert.Equal(hash_hex, Convert.ToHexString(hash).ToUpperInvariant());
+        }
     }
 }

TonLibDotNet/Cells/Cell.cs

@@ -1,4 +1,7 @@
-namespace TonLibDotNet.Cells
+using System.Buffers.Binary;
+using System.Security.Cryptography;
+
+namespace TonLibDotNet.Cells
 {
     public class Cell
     {
@@ -7,7 +10,7 @@ public class Cell
         public const int MaxRefs = 4;
 
         public Cell(ReadOnlySpan<byte> content, bool isAugmented, ICollection<Cell>? refs = null)
-            : this (false, 0, content, isAugmented, refs)
+            : this(false, 0, content, isAugmented, refs)
         {
             // Nothing.
         }
@@ -54,11 +57,14 @@ public Cell(bool isExotic, byte level, ReadOnlySpan<byte> content, bool isAugmen
             this.IsAugmented = isAugmented;
 
             this.Refs = refs?.ToList().AsReadOnly() ?? new List<Cell>().AsReadOnly();
+            this.Depth = Refs.Count == 0 ? (short)0 : (short)(Refs.Max(x => x.Depth) + 1);
         }
 
-        public bool IsExotic { get; set; }
+        public bool IsExotic { get; init; }
+
+        public byte Level { get; init; }
 
-        public byte Level { get; set; }
+        public short Depth { get; init; }
 
         public byte[] Content { get; init; }
 
@@ -68,6 +74,8 @@ public Cell(bool isExotic, byte level, ReadOnlySpan<byte> content, bool isAugmen
 
         public int BitsCount { get; protected set; }
 
+        private byte[]? hashValue;
+
         public static (byte refCount, bool isExotic, byte level, int dataLength, bool isAugmented) ParseDescriptors(byte d1, byte d2)
         {
             var refCount = d1 & 0b111;
@@ -101,12 +109,45 @@ public Slice BeginRead()
         {
             var bits = new bool[BitsCount];
 
-            for(var i = 0; i < BitsCount; i++)
+            for (var i = 0; i < BitsCount; i++)
             {
                 bits[i] = (Content[i / 8] & (0b1000_0000 >> (i & 0b111))) != 0;
             }
 
             return new Slice(new ArraySegment<bool>(bits, 0, BitsCount), Refs);
         }
+
+        public byte[] Hash()
+        {
+            if (hashValue == null)
+            {
+                var bytes = new byte[2 + Content.Length + Refs.Count * (2 + 32)];
+
+                var (d1, d2) = GetDescriptors();
+                bytes[0] = d1;
+                bytes[1] = d2;
+                Content.CopyTo(bytes, 2);
+
+                var pos = 2 + Content.Length;
+
+                Span<byte> depth = stackalloc byte[2];
+                foreach (var r in Refs)
+                {
+                    BinaryPrimitives.WriteInt16BigEndian(depth, r.Depth);
+                    depth.CopyTo(bytes.AsSpan(pos, 2));
+                    pos += 2;
+                }
+
+                foreach (var r in Refs)
+                {
+                    r.Hash().CopyTo(bytes, pos);
+                    pos += 32;
+                }
+
+                hashValue = SHA256.HashData(bytes);
+            }
+
+            return hashValue;
+        }
     }
 }