pikpak: implement custom hash to replace wrong sha1

This improves PikPak's file integrity verification by implementing a custom 
hash function named gcid and replacing the previously used SHA-1 hash.

backend/pikpak/api/types.go

@@ -176,7 +176,7 @@ type File struct {
 	FileCategory      string        `json:"file_category,omitempty"` // "AUDIO", "VIDEO"
 	FileExtension     string        `json:"file_extension,omitempty"`
 	FolderType        string        `json:"folder_type,omitempty"`
-	Hash              string        `json:"hash,omitempty"` // sha1 but NOT a valid file hash. looks like a torrent hash
+	Hash              string        `json:"hash,omitempty"` // custom hash with a form of sha1sum
 	IconLink          string        `json:"icon_link,omitempty"`
 	ID                string        `json:"id,omitempty"`
 	Kind              string        `json:"kind,omitempty"` // "drive#file"
@@ -486,7 +486,7 @@ type RequestNewFile struct {
 	ParentID   string `json:"parent_id"`
 	FolderType string `json:"folder_type"`
 	// only when uploading a new file
-	Hash       string            `json:"hash,omitempty"`      // sha1sum
+	Hash       string            `json:"hash,omitempty"`      // gcid
 	Resumable  map[string]string `json:"resumable,omitempty"` // {"provider": "PROVIDER_ALIYUN"}
 	Size       int64             `json:"size,omitempty"`
 	UploadType string            `json:"upload_type,omitempty"` // "UPLOAD_TYPE_FORM" or "UPLOAD_TYPE_RESUMABLE"

backend/pikpak/helper.go

@@ -20,7 +20,7 @@ import (
 
 // Globals
 const (
-	cachePrefix = "rclone-pikpak-sha1sum-"
+	cachePrefix = "rclone-pikpak-gcid-"
 )
 
 // requestDecompress requests decompress of compressed files
@@ -151,6 +151,9 @@ func (f *Fs) getFile(ctx context.Context, ID string) (info *api.File, err error)
 		}
 		return f.shouldRetry(ctx, resp, err)
 	})
+	if err == nil {
+		info.Name = f.opt.Enc.ToStandardName(info.Name)
+	}
 	return
 }
 
@@ -250,16 +253,11 @@ func (f *Fs) requestShare(ctx context.Context, req *api.RequestShare) (info *api
 	return
 }
 
-// Read the sha1 of in returning a reader which will read the same contents
+// Read the gcid of in returning a reader which will read the same contents
 //
 // The cleanup function should be called when out is finished with
 // regardless of whether this function returned an error or not.
-func readSHA1(in io.Reader, size, threshold int64) (sha1sum string, out io.Reader, cleanup func(), err error) {
+func readGcid(in io.Reader, size, threshold int64) (gcid string, out io.Reader, cleanup func(), err error) {
-	// we need an SHA1
-	hash := sha1.New()
-	// use the teeReader to write to the local file AND calculate the SHA1 while doing so
-	teeReader := io.TeeReader(in, hash)
-
 	// nothing to clean up by default
 	cleanup = func() {}
 
@@ -282,8 +280,11 @@ func readSHA1(in io.Reader, size, threshold int64) (sha1sum string, out io.Reade
 			_ = os.Remove(tempFile.Name()) // delete the cache file after we are done - may be deleted already
 		}
 
-		// copy the ENTIRE file to disc and calculate the SHA1 in the process
+		// use the teeReader to write to the local file AND calculate the gcid while doing so
-		if _, err = io.Copy(tempFile, teeReader); err != nil {
+		teeReader := io.TeeReader(in, tempFile)
+
+		// copy the ENTIRE file to disk and calculate the gcid in the process
+		if gcid, err = calcGcid(teeReader, size); err != nil {
 			return
 		}
 		// jump to the start of the local file so we can pass it along
@@ -294,15 +295,38 @@ func readSHA1(in io.Reader, size, threshold int64) (sha1sum string, out io.Reade
 		// replace the already read source with a reader of our cached file
 		out = tempFile
 	} else {
-		// that's a small file, just read it into memory
+		buf := &bytes.Buffer{}
-		var inData []byte
+		teeReader := io.TeeReader(in, buf)
-		inData, err = io.ReadAll(teeReader)
+
-		if err != nil {
+		if gcid, err = calcGcid(teeReader, size); err != nil {
 			return
 		}
-
+		out = buf
-		// set the reader to our read memory block
-		out = bytes.NewReader(inData)
 	}
-	return hex.EncodeToString(hash.Sum(nil)), out, cleanup, nil
+	return
+}
+
+func calcGcid(r io.Reader, size int64) (string, error) {
+	calcBlockSize := func(j int64) int64 {
+		var psize int64 = 0x40000
+		for float64(j)/float64(psize) > 0x200 && psize < 0x200000 {
+			psize = psize << 1
+		}
+		return psize
+	}
+
+	totalHash := sha1.New()
+	blockHash := sha1.New()
+	readSize := calcBlockSize(size)
+	for {
+		blockHash.Reset()
+		if n, err := io.CopyN(blockHash, r, readSize); err != nil && n == 0 {
+			if err != io.EOF {
+				return "", err
+			}
+			break
+		}
+		totalHash.Write(blockHash.Sum(nil))
+	}
+	return hex.EncodeToString(totalHash.Sum(nil)), nil
 }

backend/pikpak/pikpak.go

@@ -7,8 +7,6 @@ package pikpak
 
 // md5sum is not always available, sometimes given empty.
 
-// sha1sum used for upload differs from the one with official apps.
-
 // Trashed files are not restored to the original location when using `batchUntrash`
 
 // Can't stream without `--vfs-cache-mode=full`
@@ -291,6 +289,7 @@ type Object struct {
 	modTime     time.Time // modification time of the object
 	mimeType    string    // The object MIME type
 	parent      string    // ID of the parent directories
+	gcid        string    // custom hash of the object
 	md5sum      string    // md5sum of the object
 	link        *api.Link // link to download the object
 	linkMu      *sync.Mutex
@@ -1224,7 +1223,7 @@ func (f *Fs) uploadByResumable(ctx context.Context, in io.Reader, name string, s
 	return
 }
 
-func (f *Fs) upload(ctx context.Context, in io.Reader, leaf, dirID, sha1Str string, size int64, options ...fs.OpenOption) (info *api.File, err error) {
+func (f *Fs) upload(ctx context.Context, in io.Reader, leaf, dirID, gcid string, size int64, options ...fs.OpenOption) (info *api.File, err error) {
 	// determine upload type
 	uploadType := api.UploadTypeResumable
 	// if size >= 0 && size < int64(5*fs.Mebi) {
@@ -1239,7 +1238,7 @@ func (f *Fs) upload(ctx context.Context, in io.Reader, leaf, dirID, sha1Str stri
 		ParentID:   parentIDForRequest(dirID),
 		FolderType: "NORMAL",
 		Size:       size,
-		Hash:       strings.ToUpper(sha1Str),
+		Hash:       strings.ToUpper(gcid),
 		UploadType: uploadType,
 	}
 	if uploadType == api.UploadTypeResumable {
@@ -1503,6 +1502,7 @@ func (o *Object) setMetaData(info *api.File) (err error) {
 	} else {
 		o.parent = info.ParentID
 	}
+	o.gcid = info.Hash
 	o.md5sum = info.Md5Checksum
 	if info.Links.ApplicationOctetStream != nil {
 		o.link = info.Links.ApplicationOctetStream
@@ -1576,9 +1576,6 @@ func (o *Object) Hash(ctx context.Context, t hash.Type) (string, error) {
 	if t != hash.MD5 {
 		return "", hash.ErrUnsupported
 	}
-	if o.md5sum == "" {
-		return "", nil
-	}
 	return strings.ToLower(o.md5sum), nil
 }
 
@@ -1702,25 +1699,23 @@ func (o *Object) upload(ctx context.Context, in io.Reader, src fs.ObjectInfo, wi
 		return err
 	}
 
-	// Calculate sha1sum; grabbed from package jottacloud
+	// Calculate gcid; grabbed from package jottacloud
-	hashStr, err := src.Hash(ctx, hash.SHA1)
+	var gcid string
-	if err != nil || hashStr == "" {
+	// unwrap the accounting from the input, we use wrap to put it
-		// unwrap the accounting from the input, we use wrap to put it
+	// back on after the buffering
-		// back on after the buffering
+	var wrap accounting.WrapFn
-		var wrap accounting.WrapFn
+	in, wrap = accounting.UnWrap(in)
-		in, wrap = accounting.UnWrap(in)
+	var cleanup func()
-		var cleanup func()
+	gcid, in, cleanup, err = readGcid(in, size, int64(o.fs.opt.HashMemoryThreshold))
-		hashStr, in, cleanup, err = readSHA1(in, size, int64(o.fs.opt.HashMemoryThreshold))
+	defer cleanup()
-		defer cleanup()
+	if err != nil {
-		if err != nil {
+		return fmt.Errorf("failed to calculate gcid: %w", err)
-			return fmt.Errorf("failed to calculate SHA1: %w", err)
-		}
-		// Wrap the accounting back onto the stream
-		in = wrap(in)
 	}
+	// Wrap the accounting back onto the stream
+	in = wrap(in)
 
 	if !withTemp {
-		info, err := o.fs.upload(ctx, in, leaf, dirID, hashStr, size, options...)
+		info, err := o.fs.upload(ctx, in, leaf, dirID, gcid, size, options...)
 		if err != nil {
 			return err
 		}
@@ -1729,7 +1724,7 @@ func (o *Object) upload(ctx context.Context, in io.Reader, src fs.ObjectInfo, wi
 
 	// We have to fall back to upload + rename
 	tempName := "rcloneTemp" + random.String(8)
-	info, err := o.fs.upload(ctx, in, tempName, dirID, hashStr, size, options...)
+	info, err := o.fs.upload(ctx, in, tempName, dirID, gcid, size, options...)
 	if err != nil {
 		return err
 	}