test: anchor crypto and RLP tests to independent expectations

src/Nethermind/Nethermind.Core.Test/Encoding/BlockDecoderTests.cs

@@ -3,14 +3,12 @@
 
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using Nethermind.Core.Crypto;
 using Nethermind.Core.Extensions;
 using Nethermind.Core.Test.Builders;
 using Nethermind.Crypto;
 using Nethermind.Int256;
-using Nethermind.Logging;
 using Nethermind.Serialization.Rlp;
 using NUnit.Framework;
 
@@ -96,6 +94,21 @@ private static Block[] BuildScenarios()
                 .WithBlobGasUsed(ulong.MaxValue)
                 .WithExcessBlobGas(ulong.MaxValue)
                 .WithMixHash(Keccak.EmptyTreeHash)
+                .TestObject,
+            // This scenario sets every optional tail field, with a distinct value per field. This makes the field comparisons discriminating.
+            Build.A.Block.WithNumber(1)
+                .WithBaseFeePerGas(3)
+                .WithTransactions(transactions)
+                .WithUncles(uncles)
+                .WithWithdrawals(8)
+                .WithBloom(new Bloom([Build.A.LogEntry.TestObject]))
+                .WithBlobGasUsed(1)
+                .WithExcessBlobGas(2)
+                .WithParentBeaconBlockRoot(TestItem.KeccakA)
+                .WithRequestsHash(TestItem.KeccakB)
+                .WithBlockAccessListHash(TestItem.KeccakC)
+                .WithSlotNumber(7)
+                .WithMixHash(Keccak.EmptyTreeHash)
                 .TestObject
         ];
     }
@@ -125,7 +138,29 @@ public void Can_do_roundtrip_regression()
         RlpReader ctx = new(bytes);
         Block? decoded = decoder.Decode(ref ctx);
         Rlp encoded = decoder.Encode(decoded);
-        Assert.That(encoded.Bytes.ToHexString(), Is.EqualTo(bytes.ToHexString()));
+
+        // An independent pyrlp decode of the fixed bytes produced the expected values.
+        // Only this test decodes canonical wire. Only these asserts can find a self-canceling encode/decode error.
+        Assert.That(decoded, Is.Not.Null);
+        Assert.That(decoded!.Transactions, Has.Length.EqualTo(1));
+        Transaction tx = decoded.Transactions[0];
+        using (Assert.EnterMultipleScope())
+        {
+            Assert.That(encoded.Bytes.ToHexString(), Is.EqualTo(bytes.ToHexString()));
+            Assert.That(decoded.Header.Number, Is.EqualTo(5644UL));
+            Assert.That(decoded.Header.Difficulty, Is.EqualTo(UInt256.One));
+            Assert.That(decoded.Header.Beneficiary, Is.EqualTo(Address.Zero));
+            Assert.That(decoded.Header.GasLimit, Is.EqualTo(8_000_000UL));
+            Assert.That(decoded.Header.GasUsed, Is.EqualTo(21_000UL));
+            Assert.That(decoded.Header.Timestamp, Is.EqualTo(1549034638UL));
+            Assert.That(decoded.Header.StateRoot, Is.EqualTo(new Hash256("0xfe77dd4ad7c2a3fa4c11868a00e4d728adcdfef8d2e3c13b256b06cbdbb02ec9")));
+            Assert.That(tx.Nonce, Is.EqualTo(0UL));
+            Assert.That(tx.GasPrice, Is.EqualTo((UInt256)1_000_000_000));
+            Assert.That(tx.GasLimit, Is.EqualTo(21_000UL));
+            Assert.That(tx.To, Is.EqualTo(new Address("0x22ea9f6b28db76a7162054c05ed812deb2f519cd")));
+            Assert.That(tx.Value, Is.EqualTo(UInt256.Parse("100000000000000000000000")));
+            Assert.That(decoded.Uncles, Is.Empty);
+        }
     }
 
     [Test]
@@ -137,14 +172,53 @@ public void Can_do_roundtrip_scenarios(
         RlpReader ctx = new(encoded.Bytes);
         Block? decoded = decoder.Decode(ref ctx);
         Rlp encoded2 = decoder.Encode(decoded);
-        Assert.That(encoded2.Bytes.ToHexString(), Is.EqualTo(encoded.Bytes.ToHexString()));
-    }
 
-    [TestCase("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")]
-    [Ignore("The test is useful for debugging hive - shouldn't be executed on CI")]
-    public void Write_rlp_of_blocks_to_file(string rlp) =>
-        // the test is useful for debugging hive
-        File.WriteAllBytes("chains\\block1.rlp".GetApplicationResourcePath(), Bytes.FromHexString(rlp));
+        // A re-encode comparison cannot find a decode error that the matching encode hides. The field
+        // comparisons below can. A fully self-canceling encode/decode pair passes both; only a test
+        // that decodes canonical wire, like Can_do_roundtrip_regression, can find that class.
+        Assert.That(decoded, Is.Not.Null);
+        Assert.That(decoded!.Transactions, Has.Length.EqualTo(block.Transactions.Length));
+        using (Assert.EnterMultipleScope())
+        {
+            Assert.That(encoded2.Bytes.ToHexString(), Is.EqualTo(encoded.Bytes.ToHexString()));
+            // The hash pins the embedded header bytes against the standalone header encoding. It cannot find decode errors.
+            Assert.That(decoded.Hash, Is.EqualTo(block.Hash));
+
+            BlockHeader actual = decoded.Header;
+            BlockHeader expected = block.Header;
+            Assert.That(actual.ParentHash, Is.EqualTo(expected.ParentHash));
+            Assert.That(actual.UnclesHash, Is.EqualTo(expected.UnclesHash));
+            Assert.That(actual.Beneficiary, Is.EqualTo(expected.Beneficiary));
+            Assert.That(actual.StateRoot, Is.EqualTo(expected.StateRoot));
+            Assert.That(actual.TxRoot, Is.EqualTo(expected.TxRoot));
+            Assert.That(actual.ReceiptsRoot, Is.EqualTo(expected.ReceiptsRoot));
+            Assert.That(actual.Bloom, Is.EqualTo(expected.Bloom));
+            Assert.That(actual.Difficulty, Is.EqualTo(expected.Difficulty));
+            Assert.That(actual.Number, Is.EqualTo(expected.Number));
+            Assert.That(actual.GasLimit, Is.EqualTo(expected.GasLimit));
+            Assert.That(actual.GasUsed, Is.EqualTo(expected.GasUsed));
+            Assert.That(actual.Timestamp, Is.EqualTo(expected.Timestamp));
+            Assert.That(actual.ExtraData, Is.EqualTo(expected.ExtraData));
+            Assert.That(actual.Nonce, Is.EqualTo(expected.Nonce));
+            Assert.That(actual.BaseFeePerGas, Is.EqualTo(expected.BaseFeePerGas));
+            Assert.That(actual.WithdrawalsRoot, Is.EqualTo(expected.WithdrawalsRoot));
+            Assert.That(actual.BlobGasUsed, Is.EqualTo(expected.BlobGasUsed));
+            Assert.That(actual.ExcessBlobGas, Is.EqualTo(expected.ExcessBlobGas));
+            Assert.That(actual.MixHash, Is.EqualTo(expected.MixHash));
+            Assert.That(actual.ParentBeaconBlockRoot, Is.EqualTo(expected.ParentBeaconBlockRoot));
+            Assert.That(actual.RequestsHash, Is.EqualTo(expected.RequestsHash));
+            Assert.That(actual.BlockAccessListHash, Is.EqualTo(expected.BlockAccessListHash));
+            Assert.That(actual.SlotNumber, Is.EqualTo(expected.SlotNumber));
+
+            for (int i = 0; i < block.Transactions.Length; i++)
+            {
+                Assert.That(decoded.Transactions[i].Hash, Is.EqualTo(block.Transactions[i].Hash), $"transaction {i}");
+            }
+
+            Assert.That(decoded.Uncles.Length, Is.EqualTo(block.Uncles.Length));
+            Assert.That(decoded.Withdrawals?.Length, Is.EqualTo(block.Withdrawals?.Length));
+        }
+    }
 
     [Test]
     public void Encode_with_pre_encoded_transactions_produces_same_rlp(

src/Nethermind/Nethermind.Core.Test/KeccakTests.cs

@@ -151,15 +151,21 @@ public void Compare(string a, string? b, int result)
         public void CompareSameInstance() => Assert.That(Keccak.Zero.CompareTo(Keccak.Zero), Is.EqualTo(0));
 
         [Test]
-        public void Span()
+        public void Computes_known_hash_for_span_and_array()
         {
             byte[] byteArray = new byte[1024];
             for (int i = 0; i < byteArray.Length; i++)
             {
                 byteArray[i] = (byte)(i % 256);
             }
 
-            Assert.That(Keccak.Compute(byteArray.AsSpan()), Is.EqualTo(Keccak.Compute(byteArray)));
+            // An independent keccak-256 implementation (pycryptodome) produced the expected hash.
+            Hash256 expected = new("0x5902e53903be0d0f9656bdbd5b9f0d8c2d815f865645d629eef77f5185f6cd7f");
+            using (Assert.EnterMultipleScope())
+            {
+                Assert.That(Keccak.Compute(byteArray.AsSpan()), Is.EqualTo(expected));
+                Assert.That(Keccak.Compute(byteArray), Is.EqualTo(expected));
+            }
         }
 
         [TestCase("0x", "c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470")]

src/Nethermind/Nethermind.Core.Test/RlpTests.cs

@@ -281,7 +281,37 @@ public void Length_of_uint()
         }
 
         [Test]
-        public void Length_of_ulong_same_as_uint256([ValueSource(nameof(ULongValues))] ulong value) => Assert.That(Rlp.LengthOf(value), Is.EqualTo(Rlp.LengthOf((UInt256)value)));
+        public void Length_of_ulong_matches_spec([ValueSource(nameof(ULongValues))] ulong value)
+        {
+            int expected = SpecLengthOf(value);
+            using (Assert.EnterMultipleScope())
+            {
+                Assert.That(Rlp.LengthOf(value), Is.EqualTo(expected), "ulong");
+                Assert.That(Rlp.LengthOf((UInt256)value), Is.EqualTo(expected), "UInt256");
+            }
+        }
+
+        /// <summary>Computes the RLP length of an unsigned integer.</summary>
+        /// <remarks>
+        /// Yellow Paper appendix B gives the length. A value below 0x80 uses one byte. Larger values use
+        /// one prefix byte plus the minimal big-endian bytes. The loop shape is deliberately different from
+        /// the production implementation. This prevents a defect shared with the production code.
+        /// </remarks>
+        private static int SpecLengthOf(ulong value)
+        {
+            if (value < 0x80)
+            {
+                return 1;
+            }
+
+            int byteCount = 0;
+            for (ulong rest = value; rest != 0; rest >>= 8)
+            {
+                byteCount++;
+            }
+
+            return 1 + byteCount;
+        }
 
         [Test]
         public void Single_byte_encoding_decoding()