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mirror of https://github.com/octoleo/restic.git synced 2024-12-23 19:38:57 +00:00
restic/internal/selfupdate/download.go
Michael Eischer ff7ef5007e Replace most usages of ioutil with the underlying function
The ioutil functions are deprecated since Go 1.17 and only wrap another
library function. Thus directly call the underlying function.

This commit only mechanically replaces the function calls.
2022-12-02 19:36:43 +01:00

182 lines
3.8 KiB
Go

package selfupdate
import (
"archive/zip"
"bufio"
"bytes"
"compress/bzip2"
"context"
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"os"
"path/filepath"
"runtime"
"strings"
"github.com/pkg/errors"
)
func findHash(buf []byte, filename string) (hash []byte, err error) {
sc := bufio.NewScanner(bytes.NewReader(buf))
for sc.Scan() {
data := strings.Split(sc.Text(), " ")
if len(data) != 2 {
continue
}
if data[1] == filename {
h, err := hex.DecodeString(data[0])
if err != nil {
return nil, err
}
return h, nil
}
}
return nil, fmt.Errorf("hash for file %v not found", filename)
}
func extractToFile(buf []byte, filename, target string, printf func(string, ...interface{})) error {
var rd io.Reader = bytes.NewReader(buf)
switch filepath.Ext(filename) {
case ".bz2":
rd = bzip2.NewReader(rd)
case ".zip":
zrd, err := zip.NewReader(bytes.NewReader(buf), int64(len(buf)))
if err != nil {
return err
}
if len(zrd.File) != 1 {
return errors.New("ZIP archive contains more than one file")
}
file, err := zrd.File[0].Open()
if err != nil {
return err
}
defer func() {
_ = file.Close()
}()
rd = file
}
// Write everything to a temp file
dir := filepath.Dir(target)
new, err := os.CreateTemp(dir, "restic")
if err != nil {
return err
}
n, err := io.Copy(new, rd)
if err != nil {
_ = new.Close()
_ = os.Remove(new.Name())
return err
}
if err = new.Sync(); err != nil {
return err
}
if err = new.Close(); err != nil {
return err
}
mode := os.FileMode(0755)
// attempt to find the original mode
if fi, err := os.Lstat(target); err == nil {
mode = fi.Mode()
}
// Remove the original binary.
if err := removeResticBinary(dir, target); err != nil {
return err
}
// Rename the temp file to the final location atomically.
if err := os.Rename(new.Name(), target); err != nil {
return err
}
printf("saved %d bytes in %v\n", n, target)
return os.Chmod(target, mode)
}
// DownloadLatestStableRelease downloads the latest stable released version of
// restic and saves it to target. It returns the version string for the newest
// version. The function printf is used to print progress information.
func DownloadLatestStableRelease(ctx context.Context, target, currentVersion string, printf func(string, ...interface{})) (version string, err error) {
if printf == nil {
printf = func(string, ...interface{}) {}
}
printf("find latest release of restic at GitHub\n")
rel, err := GitHubLatestRelease(ctx, "restic", "restic")
if err != nil {
return "", err
}
if rel.Version == currentVersion {
printf("restic is up to date\n")
return currentVersion, nil
}
printf("latest version is %v\n", rel.Version)
_, sha256sums, err := getGithubDataFile(ctx, rel.Assets, "SHA256SUMS", printf)
if err != nil {
return "", err
}
_, sig, err := getGithubDataFile(ctx, rel.Assets, "SHA256SUMS.asc", printf)
if err != nil {
return "", err
}
ok, err := GPGVerify(sha256sums, sig)
if err != nil {
return "", err
}
if !ok {
return "", errors.New("GPG signature verification of the file SHA256SUMS failed")
}
printf("GPG signature verification succeeded\n")
ext := "bz2"
if runtime.GOOS == "windows" {
ext = "zip"
}
suffix := fmt.Sprintf("%s_%s.%s", runtime.GOOS, runtime.GOARCH, ext)
downloadFilename, buf, err := getGithubDataFile(ctx, rel.Assets, suffix, printf)
if err != nil {
return "", err
}
printf("downloaded %v\n", downloadFilename)
wantHash, err := findHash(sha256sums, downloadFilename)
if err != nil {
return "", err
}
gotHash := sha256.Sum256(buf)
if !bytes.Equal(wantHash, gotHash[:]) {
return "", fmt.Errorf("SHA256 hash mismatch, want hash %02x, got %02x", wantHash, gotHash)
}
err = extractToFile(buf, downloadFilename, target, printf)
if err != nil {
return "", err
}
return rel.Version, nil
}