go-blockchain/consensus/pow.go
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refactor: migrate module path to dappco.re/go/core/blockchain
Update go.mod module line, all require/replace directives, and every
.go import path from forge.lthn.ai/core/go-blockchain to
dappco.re/go/core/blockchain. Add replace directives to bridge
dappco.re paths to existing forge.lthn.ai registry during migration.
Update CLAUDE.md, README, and docs to reflect the new module path.

Co-Authored-By: Virgil <virgil@lethean.io>
2026-03-22 01:49:26 +00:00

55 lines
1.5 KiB
Go

// Copyright (c) 2017-2026 Lethean (https://lt.hn)
//
// Licensed under the European Union Public Licence (EUPL) version 1.2.
// SPDX-License-Identifier: EUPL-1.2
package consensus
import (
"encoding/binary"
"math/big"
"dappco.re/go/core/blockchain/crypto"
"dappco.re/go/core/blockchain/types"
)
// maxTarget is 2^256, used for difficulty comparison.
var maxTarget = new(big.Int).Lsh(big.NewInt(1), 256)
// CheckDifficulty returns true if hash meets the given difficulty target.
// The hash (interpreted as a 256-bit little-endian number) must be less
// than maxTarget / difficulty.
func CheckDifficulty(hash types.Hash, difficulty uint64) bool {
if difficulty == 0 {
return true
}
// Convert hash to big.Int (little-endian as per CryptoNote convention).
// Reverse to big-endian for big.Int.
var be [32]byte
for i := range 32 {
be[i] = hash[31-i]
}
hashInt := new(big.Int).SetBytes(be[:])
target := new(big.Int).Div(maxTarget, new(big.Int).SetUint64(difficulty))
return hashInt.Cmp(target) < 0
}
// CheckPoWHash computes the RandomX hash of a block header hash + nonce
// and checks it against the difficulty target.
func CheckPoWHash(headerHash types.Hash, nonce, difficulty uint64) (bool, error) {
// Build input: header_hash (32 bytes) || nonce (8 bytes LE).
var input [40]byte
copy(input[:32], headerHash[:])
binary.LittleEndian.PutUint64(input[32:], nonce)
key := []byte("LetheanRandomXv1")
powHash, err := crypto.RandomXHash(key, input[:])
if err != nil {
return false, err
}
return CheckDifficulty(types.Hash(powHash), difficulty), nil
}