linsk/storage/hash.go
2023-09-02 20:03:44 +01:00

64 lines
1.6 KiB
Go

// Linsk - A utility to access Linux-native file systems on non-Linux operating systems.
// Copyright (c) 2023 The Linsk Authors.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package storage
import (
"bytes"
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"os"
"path/filepath"
"github.com/pkg/errors"
)
func validateFileHash(path string, hash []byte) error {
pathClean := filepath.Clean(path)
f, err := os.OpenFile(pathClean, os.O_RDONLY, 0400)
if err != nil {
return errors.Wrap(err, "open file")
}
defer func() { _ = f.Close() }()
h := sha256.New()
block := make([]byte, 1024)
for {
read, err := f.Read(block)
if read > 0 {
h.Write(block[:read])
}
if err != nil {
if errors.Is(err, io.EOF) {
break
}
return errors.Wrap(err, "read file block")
}
}
sum := h.Sum(nil)
if !bytes.Equal(sum, hash) {
return fmt.Errorf("hash mismatch: want '%v', have '%v' (path '%v')", hex.EncodeToString(hash), hex.EncodeToString(sum), pathClean)
}
return nil
}