Blockchain setup

internal/blockchain/block.go

@@ -1 +1,22 @@
-package blockchain
+package main
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"strconv"
+)
+
+type Block struct {
+	Timestamp     int64
+	Data          []byte // Transactions
+	prevBlockHash []byte
+	Hash          []byte
+	Counter       int // Nonce
+}
+
+func (b *Block) SetHash() {
+	timestamp := []byte(strconv.FormatInt(b.Timestamp, 10))
+	headers := bytes.Join([][]byte{b.prevBlockHash, b.Data, timestamp}, []byte{})
+	hash := sha256.Sum256(headers)
+	b.Hash = hash[:]
+}

internal/blockchain/blockchain.go

@@ -0,0 +1,5 @@
+package main
+
+type Blockchain struct {
+	blocks []*Block
+}

internal/blockchain/proof_of_work.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"math/big"
+)
+
+const Difficulty = 16
+
+type ProofOfWork struct {
+	block *Block
+	T     big.Int
+}
+
+func NewProofOfWork(b *Block) *ProofOfWork {
+	target := big.NewInt(1)
+	target.Lsh(target, uint(256-Difficulty))
+
+	pow := &ProofOfWork{b, *target}
+
+	return pow
+}

internal/blockchain/validantions.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"fmt"
+	"reflect"
+	"time"
+)
+
+type Receive func() string
+type Input func() string
+
+/*
+func ValidateBlockPredicate(b *Block) bool {
+
+}
+*/
+
+// Simple Content Validation Predicate implementation from backbone protocol
+func ContentValidatePredicate(x *Blockchain) bool {
+
+	if len(x.blocks) == 0 {
+		return false
+	}
+
+	for i := range x.blocks {
+		if i == 0 {
+			continue
+		}
+		if reflect.DeepEqual(x.blocks[i].Hash, x.blocks[i-1].Hash) {
+			return false
+		}
+	}
+	return true
+}
+
+func InputContributionFunction(data []byte, cr *Blockchain, round int, input Input, receive Receive) {
+
+	input_data := input()
+	receive_data := receive()
+
+	concat_data := input_data + receive_data
+	// creating new block
+
+	newBlock := &Block{time.Now().Unix(), []byte(concat_data), cr.blocks[len(cr.blocks)-1].Hash, []byte{}, round}
+	cr.blocks = append(cr.blocks, newBlock)
+
+	if !ContentValidatePredicate(cr) {
+		fmt.Println("Content Validation Failed")
+		cr.blocks = cr.blocks[:len(cr.blocks)-1]
+	} else {
+		fmt.Println("Content Validation Passed")
+	}
+}
+
+// Function to read the chain
+func ChainReadFunction(c *Blockchain) string {
+	data := ""
+	for i := range c.blocks {
+		data += string(c.blocks[i].Data)
+	}
+	return data
+}
+
+/*func ChainValidationPredicate(c *Blockchain) bool {
+	b := ContentValidatePredicate(c)
+
+	if b && c != nil {
+		index := rand.Intn(len(c.blocks))
+		temp_chain := c
+		c.blocks[index].SetHash()
+
+		for i := true; i; b = false{
+			if
+		}
+	}
+	return b
+}
+*/