Golang BlockHeader.BlockHash方法代码示例

// checkProofOfWork ensures the block header bits which indicate the target
// difficulty is in min/max range and that the block hash is less than the
// target difficulty as claimed.
//
// The flags modify the behavior of this function as follows:
//  - BFNoPoWCheck: The check to ensure the block hash is less than the target
//    difficulty is not performed.
func checkProofOfWork(header *wire.BlockHeader, powLimit *big.Int, flags BehaviorFlags) error {
	// The target difficulty must be larger than zero.
	target := CompactToBig(header.Bits)
	if target.Sign() <= 0 {
		str := fmt.Sprintf("block target difficulty of %064x is too low",
			target)
		return ruleError(ErrUnexpectedDifficulty, str)
	}

	// The target difficulty must be less than the maximum allowed.
	if target.Cmp(powLimit) > 0 {
		str := fmt.Sprintf("block target difficulty of %064x is "+
			"higher than max of %064x", target, powLimit)
		return ruleError(ErrUnexpectedDifficulty, str)
	}

	// The block hash must be less than the claimed target unless the flag
	// to avoid proof of work checks is set.
	if flags&BFNoPoWCheck != BFNoPoWCheck {
		// The block hash must be less than the claimed target.
		hash := header.BlockHash()
		hashNum := HashToBig(&hash)
		if hashNum.Cmp(target) > 0 {
			str := fmt.Sprintf("block hash of %064x is higher than "+
				"expected max of %064x", hashNum, target)
			return ruleError(ErrHighHash, str)
		}
	}

	return nil
}

// checkBlockHeaderContext peforms several validation checks on the block header
// which depend on its position within the block chain.
//
// The flags modify the behavior of this function as follows:
//  - BFFastAdd: All checks except those involving comparing the header against
//    the checkpoints are not performed.
//
// This function MUST be called with the chain state lock held (for writes).
func (b *BlockChain) checkBlockHeaderContext(header *wire.BlockHeader, prevNode *blockNode, flags BehaviorFlags) error {
	// The genesis block is valid by definition.
	if prevNode == nil {
		return nil
	}

	fastAdd := flags&BFFastAdd == BFFastAdd
	if !fastAdd {
		// Ensure the difficulty specified in the block header matches
		// the calculated difficulty based on the previous block and
		// difficulty retarget rules.
		expectedDifficulty, err := b.calcNextRequiredDifficulty(prevNode,
			header.Timestamp)
		if err != nil {
			return err
		}
		blockDifficulty := header.Bits
		if blockDifficulty != expectedDifficulty {
			str := "block difficulty of %d is not the expected value of %d"
			str = fmt.Sprintf(str, blockDifficulty, expectedDifficulty)
			return ruleError(ErrUnexpectedDifficulty, str)
		}

		// Ensure the timestamp for the block header is after the
		// median time of the last several blocks (medianTimeBlocks).
		medianTime, err := b.calcPastMedianTime(prevNode)
		if err != nil {
			log.Errorf("calcPastMedianTime: %v", err)
			return err
		}
		if !header.Timestamp.After(medianTime) {
			str := "block timestamp of %v is not after expected %v"
			str = fmt.Sprintf(str, header.Timestamp, medianTime)
			return ruleError(ErrTimeTooOld, str)
		}
	}

	// The height of this block is one more than the referenced previous
	// block.
	blockHeight := prevNode.height + 1

	// Ensure chain matches up to predetermined checkpoints.
	blockHash := header.BlockHash()
	if !b.verifyCheckpoint(blockHeight, &blockHash) {
		str := fmt.Sprintf("block at height %d does not match "+
			"checkpoint hash", blockHeight)
		return ruleError(ErrBadCheckpoint, str)
	}

	// Find the previous checkpoint and prevent blocks which fork the main
	// chain before it.  This prevents storage of new, otherwise valid,
	// blocks which build off of old blocks that are likely at a much easier
	// difficulty and therefore could be used to waste cache and disk space.
	checkpointBlock, err := b.findPreviousCheckpoint()
	if err != nil {
		return err
	}
	if checkpointBlock != nil && blockHeight < checkpointBlock.Height() {
		str := fmt.Sprintf("block at height %d forks the main chain "+
			"before the previous checkpoint at height %d",
			blockHeight, checkpointBlock.Height())
		return ruleError(ErrForkTooOld, str)
	}

	if !fastAdd {
		// Reject version 3 blocks once a majority of the network has
		// upgraded.  This is part of BIP0065.
		if header.Version < 4 && b.isMajorityVersion(4, prevNode,
			b.chainParams.BlockRejectNumRequired) {

			str := "new blocks with version %d are no longer valid"
			str = fmt.Sprintf(str, header.Version)
			return ruleError(ErrBlockVersionTooOld, str)
		}

		// Reject version 2 blocks once a majority of the network has
		// upgraded.  This is part of BIP0066.
		if header.Version < 3 && b.isMajorityVersion(3, prevNode,
			b.chainParams.BlockRejectNumRequired) {

			str := "new blocks with version %d are no longer valid"
			str = fmt.Sprintf(str, header.Version)
			return ruleError(ErrBlockVersionTooOld, str)
		}

		// Reject version 1 blocks once a majority of the network has
		// upgraded.  This is part of BIP0034.
		if header.Version < 2 && b.isMajorityVersion(2, prevNode,
			b.chainParams.BlockRejectNumRequired) {

			str := "new blocks with version %d are no longer valid"
			str = fmt.Sprintf(str, header.Version)
//.........这里部分代码省略.........