public MerkleBlockMessage(BlockHeader blockHeader, uint totalTransactions, byte[][] hashes, byte[] flags)
{
this.blockHeader = blockHeader;
this.totalTransactions = totalTransactions;
this.hashes = new List<byte[]>(hashes);
this.flags = flags;
}
//todo: split BlockHeaderValidator to static and non-static parts
public static bool IsValid(BlockHeader header)
{
return
IsNBitsValid(header) &&
IsTimestampValid(header) &&
IsHashValid(header);
}
internal StoredBlock(BlockHeader header, byte[] hash, int height, double totalWork, bool hasContent, bool isInBestHeaderChain, bool isInBestBlockChain)
{
Header = header;
Hash = hash;
Height = height;
TotalWork = totalWork;
HasContent = hasContent;
IsInBestHeaderChain = isInBestHeaderChain;
IsInBestBlockChain = isInBestBlockChain;
}
public void TestIsTimestampValid()
{
List<StoredBlock> blocks = new List<StoredBlock>();
StoredBlock prevBlock = null;
for (int i = 0; i < 11; i++)
{
BlockHeader header = new BlockHeader
(
genesisBlockHeader.Version,
prevBlock == null ? new byte[32] : prevBlock.Hash,
new byte[32],
(uint) i,
0x21100000,
0);
StoredBlock storedBlock = new StoredBlockBuilder(header).Build();
blocks.Add(storedBlock);
prevBlock = storedBlock;
}
Subchain subchain = new Subchain(blocks);
{
BlockHeader header = new BlockHeader
(
genesisBlockHeader.Version,
new byte[32],
new byte[32],
5,
0x21100000,
0);
StoredBlock storedBlock = new StoredBlockBuilder(header).Build();
Assert.False(BlockHeaderValidator.IsTimeStampValid(storedBlock, subchain));
}
{
BlockHeader header = new BlockHeader
(
genesisBlockHeader.Version,
new byte[32],
new byte[32],
6,
0x21100000,
0);
StoredBlock storedBlock = new StoredBlockBuilder(header).Build();
Assert.True(BlockHeaderValidator.IsTimeStampValid(storedBlock, subchain));
}
}
public void TestIsHashValid()
{
Assert.True(BlockHeaderValidator.IsHashValid(genesisBlockHeader));
BlockHeader blockHeader = new BlockHeader(
genesisBlockHeader.Version,
genesisBlockHeader.PrevBlock,
genesisBlockHeader.MerkleRoot,
genesisBlockHeader.Timestamp,
genesisBlockHeader.NBits,
1);
Assert.False(BlockHeaderValidator.IsHashValid(blockHeader));
}
/// <summary>
/// Checks that a hash of the header matches nBits field in the block.
/// </summary>
internal static bool IsHashValid(BlockHeader header)
{
byte[] text = BitcoinStreamWriter.GetBytes(header.Write);
//todo: This hash is calculated too often. Save it somewhere.
byte[] hash = CryptoUtils.DoubleSha256(text);
BigInteger hashAsNumber = NumberUtils.ToBigInteger(hash);
BigInteger difficultyTarget = DifficultyUtils.NBitsToTarget(header.NBits);
if (hashAsNumber > difficultyTarget)
{
return false;
}
return true;
}
public void TestIsTimestampValidStatic()
{
BlockHeader blockHeader1 = new BlockHeader(
genesisBlockHeader.Version,
genesisBlockHeader.PrevBlock,
genesisBlockHeader.MerkleRoot,
(uint) UnixTime.ToTimestamp(DateTime.UtcNow.AddMinutes(110)),
genesisBlockHeader.NBits,
genesisBlockHeader.Nonce);
Assert.True(BlockHeaderValidator.IsTimestampValid(blockHeader1));
BlockHeader blockHeader2 = new BlockHeader(
genesisBlockHeader.Version,
genesisBlockHeader.PrevBlock,
genesisBlockHeader.MerkleRoot,
(uint) UnixTime.ToTimestamp(DateTime.UtcNow.AddMinutes(130)),
genesisBlockHeader.NBits,
genesisBlockHeader.Nonce);
Assert.False(BlockHeaderValidator.IsTimestampValid(blockHeader2));
}
public BlockMessage(BlockHeader blockHeader, Tx[] transactions)
{
this.blockHeader = blockHeader;
this.transactions = transactions;
}
public HeadersMessage(BlockHeader[] headers)
{
this.headers = headers;
}
public StoredBlockBuilder(BlockHeader header)
{
byte[] text = BitcoinStreamWriter.GetBytes(header.Write);
Header = header;
Hash = CryptoUtils.DoubleSha256(text);
Height = -1;
TotalWork = 0;
HasContent = false;
IsInBestHeaderChain = false;
IsInBestBlockChain = false;
}
/// <summary>
/// Checks that the difficulty defined by the nBits field is not lower than the network minimum.
/// </summary>
internal static bool IsNBitsValid(BlockHeader blockHeader)
{
BigInteger target = DifficultyUtils.NBitsToTarget(blockHeader.NBits);
return target <= DifficultyUtils.MaxDifficultyTarget;
}
/// <summary>
/// Checks that timestamp of the block header is not too far in the future.
/// </summary>
/// <remarks>Specification: https://en.bitcoin.it/wiki/Block_timestamp </remarks>
internal static bool IsTimestampValid(BlockHeader header)
{
//todo: Specification requires to adjust current time. Why is it necessary?
return UnixTime.ToDateTime(header.Timestamp) < SystemTime.UtcNow.AddHours(2);
}
