An implementation of a Merkle Tree written in Go. A Merkle Tree is a hash tree that provides an efficient way to verify the contents of a set data are present and untampered with.
At its core, a Merkle Tree is a list of items representing the data that should be verified. Each of these items is inserted into a leaf node and a tree of hashes is constructed bottom up using a hash of the nodes left and right children's hashes. This means that the root node will effictively be a hash of all other nodes (hashes) in the tree. This property allows the tree to be reproduced and thus verified by on the hash of the root node of the tree. The benefit of the tree structure is verifying any single content entry in the tree will require only nlog2(n) steps in the worst case.
Below is an example that makes use of the entire API - its quite small.
package main
import (
solsha3 "github.com/miguelmota/go-solidity-sha3"
"golang.org/x/crypto/sha3"
"log"
"github.com/ethereum/go-ethereum/common"
)
// Leaves implements the Content interface provided by merkletree and represents the content stored in the tree.
type Leaves struct {
types []string
params []interface{}
}
// CalculateHash hashes the values of a TestContent
func (lv Leaves) CalculateHash() ([]byte, error) {
return solsha3.SoliditySHA3(lv.types, lv.params), nil
}
// Equals tests for equality of two Contents
func (lv Leaves) Equals(other Content) (bool, error) {
if len(lv.params) != len(other.(Leaves).params) {
return false, nil
}
return true, nil
}
func main() {
//Build list of Content to build tree
var (
leavess []Content
types = []string{"uint256", "address", "uint256"}
)
leavess = append(
leavess,
Leaves{types: types, params: []interface{}{"439815793", "0x5B38Da6a701c568545dCfcB03FcB875f56beddC4", "1000"}},
Leaves{types: types, params: []interface{}{"55", "0xd3dE9c47b917baAd93F68B2c0D6dEe857D20b015", "1000"}},
Leaves{types: types, params: []interface{}{"55", "0x7cD1CB03FAE64CBab525C3263DBeB821Afd64483", "1000"}},
Leaves{types: types, params: []interface{}{"55", "0x7cD1CB03FAE64CBab525C3263DBeB821Afd64483", "1000"}},
)
tree, err := NewTreeWithHashStrategy(leaves, sha3.NewLegacyKeccak256)
if err != nil {
return merkleRoot, "", err
}
// 计算根hash
merkleRoot = fmt.Sprintf("0x%s", common.Bytes2Hex(tree.MerkleRoot()))
_, err = tree.VerifyMerkleTree()
if err != nil {
return merkleRoot, "", err
}
_, err = tree.VerifyProof(leaves[0])
if err != nil {
return merkleRoot, "", err
}
merkleProofBytes, _, err := tree.MerkleProof(leaves[0])
if err != nil {
return merkleRoot, "", err
}
// 计算proof
for _, v := range merkleProofBytes {
merkleProof = append(merkleProof, fmt.Sprintf("0x%s", common.Bytes2Hex(v)))
}
}This project is licensed under the MIT License.