safing-portmaster/service/updates/bundle.go
2024-09-20 17:36:07 +03:00

122 lines
2.9 KiB
Go

package updates
import (
"bytes"
"crypto/sha256"
"encoding/hex"
"encoding/json"
"fmt"
"io"
"os"
"path/filepath"
"runtime"
"time"
)
const MaxUnpackSize = 1 << 30 // 2^30 == 1GB
const currentPlatform = runtime.GOOS + "_" + runtime.GOARCH
type Artifact struct {
Filename string `json:"Filename"`
SHA256 string `json:"SHA256"`
URLs []string `json:"URLs"`
Platform string `json:"Platform,omitempty"`
Unpack string `json:"Unpack,omitempty"`
Version string `json:"Version,omitempty"`
}
func (a *Artifact) GetFileMode() os.FileMode {
// Special case for portmaster ui. Should be able to be executed from the regular user
if a.Platform == currentPlatform && a.Filename == "portmaster" {
return executableUIFileMode
}
if a.Platform == currentPlatform {
return executableFileMode
}
return defaultFileMode
}
type Bundle struct {
Name string `json:"Bundle"`
Version string `json:"Version"`
Published time.Time `json:"Published"`
Artifacts []Artifact `json:"Artifacts"`
}
func ParseBundle(indexFile string) (*Bundle, error) {
// Check if the file exists.
file, err := os.Open(indexFile)
if err != nil {
return nil, fmt.Errorf("failed to open index file: %w", err)
}
defer func() { _ = file.Close() }()
// Read
content, err := io.ReadAll(file)
if err != nil {
return nil, err
}
// Parse
var bundle Bundle
err = json.Unmarshal(content, &bundle)
if err != nil {
return nil, fmt.Errorf("%s %w", indexFile, err)
}
// Filter artifacts
filtered := make([]Artifact, 0)
for _, a := range bundle.Artifacts {
if a.Platform == "" || a.Platform == currentPlatform {
filtered = append(filtered, a)
}
}
bundle.Artifacts = filtered
return &bundle, nil
}
// Verify checks if the files are present int the dataDir and have the correct hash.
func (bundle Bundle) Verify(dir string) error {
for _, artifact := range bundle.Artifacts {
artifactPath := filepath.Join(dir, artifact.Filename)
isValid, err := checkIfFileIsValid(artifactPath, artifact)
if err != nil {
return err
}
if !isValid {
return fmt.Errorf("file is not valid: %s", artifact.Filename)
}
}
return nil
}
func checkIfFileIsValid(filename string, artifact Artifact) (bool, error) {
// Check if file already exists
file, err := os.Open(filename)
if err != nil {
return false, err
}
defer func() { _ = file.Close() }()
providedHash, err := hex.DecodeString(artifact.SHA256)
if err != nil || len(providedHash) != sha256.Size {
return false, fmt.Errorf("invalid provided hash %s: %w", artifact.SHA256, err)
}
// Calculate hash of the file
fileHash := sha256.New()
if _, err := io.Copy(fileHash, file); err != nil {
return false, fmt.Errorf("failed to read file: %w", err)
}
hashInBytes := fileHash.Sum(nil)
if !bytes.Equal(providedHash, hashInBytes) {
return false, fmt.Errorf("file exist but the hash does not match: %s", filename)
}
return true, nil
}