98 lines
2.0 KiB
Go
98 lines
2.0 KiB
Go
package main
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import (
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"bytes"
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"crypto/sha256"
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"encoding/gob"
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"log"
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)
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const subsidy = 10
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// Transaction represents a Bitcoin transaction
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type Transaction struct {
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Vin []TXInput
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Vout []TXOutput
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}
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// IsCoinbase checks whether the transaction is coinbase
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func (tx Transaction) IsCoinbase() bool {
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return len(tx.Vin) == 1 && tx.Vin[0].Txid == -1 && tx.Vin[0].Vout == -1
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}
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// GetHash hashes the transaction and returns the hash
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func (tx Transaction) GetHash() []byte {
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var encoded bytes.Buffer
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var hash [32]byte
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enc := gob.NewEncoder(&encoded)
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err := enc.Encode(tx)
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if err != nil {
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log.Panic(err)
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}
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hash = sha256.Sum256(encoded.Bytes())
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return hash[:]
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}
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// TXInput represents a transaction input
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type TXInput struct {
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Txid int
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Vout int
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ScriptSig string
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}
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// TXOutput represents a transaction output
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type TXOutput struct {
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Value int
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ScriptPubKey string
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}
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// Unlock checks if the output can be unlocked with the provided data
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func (out *TXOutput) Unlock(unlockingData string) bool {
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return out.ScriptPubKey == unlockingData
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}
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// NewCoinbaseTX creates a new coinbase transaction
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func NewCoinbaseTX(to, data string) *Transaction {
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if data == "" {
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data = "Coinbase"
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}
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txin := TXInput{-1, -1, data}
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txout := TXOutput{subsidy, to}
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tx := Transaction{[]TXInput{txin}, []TXOutput{txout}}
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return &tx
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}
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// NewUTXOTransaction creates a new transaction
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func NewUTXOTransaction(from, to string, value int) *Transaction {
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var inputs []TXInput
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var outputs []TXOutput
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acc, validOutputs := s.findUnspentOutputs(from, value)
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if acc < value {
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log.Panic("ERROR: Not enough funds")
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}
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// Build a list of inputs
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for txid, outs := range validOutputs {
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for _, out := range outs {
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input := TXInput{txid, out, from}
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inputs = append(inputs, input)
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}
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}
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// Build a list of outputs
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outputs = append(outputs, TXOutput{value, to})
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if acc > value {
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outputs = append(outputs, TXOutput{acc - value, from}) // a change
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}
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tx := Transaction{inputs, outputs}
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return &tx
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}
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