GoBlockChain

Added simple blockchain

Author: Packet-Swtchd

.gitignore

@@ -19,3 +19,4 @@
 
 # Go workspace file
 go.work
+.vscode/settings.json

cmd/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"Go_Blockchain/models"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"strconv"
+	"time"
+)
+
+func calculateHash(b models.Block) string {
+	record := strconv.Itoa(b.Index) + b.Timestamp + b.Data + b.PreviousHash
+	h := sha256.New()
+	h.Write([]byte(record))
+	hashed := h.Sum(nil)
+	return hex.EncodeToString(hashed)
+}
+
+func generateBlock(oldBlock models.Block, data string) (models.Block, error) {
+	var newBlock models.Block
+	t := time.Now()
+	newBlock.Index = oldBlock.Index + 1
+	newBlock.Timestamp = t.String()
+	newBlock.Data = data
+	newBlock.PreviousHash = oldBlock.Hash
+	newBlock.Hash = calculateHash(newBlock)
+
+	return newBlock, nil
+}
+
+func isBlockValid(newBlock, oldBlock models.Block) bool {
+	if oldBlock.Index+1 != newBlock.Index {
+		return false
+	}
+	if oldBlock.Hash != newBlock.PreviousHash {
+		return false
+	}
+	if calculateHash(newBlock) != newBlock.Hash {
+		return false
+	}
+	return true
+}
+
+func main() {
+	genesisBlock := models.Block{}
+	genesisBlock = models.Block{0, time.Now().String(), "Genesis Block", "", ""}
+	genesisBlock.Hash = calculateHash(genesisBlock)
+	fmt.Println(genesisBlock)
+
+	secondBlock, _ := generateBlock(genesisBlock, "Second Bock Data")
+	fmt.Println(secondBlock)
+
+	fmt.Println(isBlockValid(secondBlock, genesisBlock))
+}

go.mod

@@ -0,0 +1,3 @@
+module Go_Blockchain
+
+go 1.23.3

models/block.go

@@ -0,0 +1,9 @@
+package models
+
+type Block struct {
+	Index        int
+	Timestamp    string
+	Data         string
+	PreviousHash string
+	Hash         string
+}