feat yandex desktop downloads

internal/download/downloader.go

@@ -3,8 +3,10 @@ package download
 import (
 	"bufio"
 	"context"
+	"crypto/aes"
 	"crypto/cipher"
 	"crypto/md5"
+	"encoding/hex"
 	"fmt"
 	"io"
 	"net/http"
@@ -182,6 +184,120 @@ func (d *Downloader) FileDeezerEncrypted(ctx context.Context, sourceURL, outputP
 	return nil
 }
 
+func (d *Downloader) FileYandexEncrypted(ctx context.Context, sourceURL, outputPath, key string) error {
+	logDownloadStart(sourceURL, outputPath)
+	if err := os.MkdirAll(filepath.Dir(outputPath), 0o755); err != nil {
+		return err
+	}
+	keyBytes, err := hex.DecodeString(strings.TrimSpace(key))
+	if err != nil {
+		return fmt.Errorf("invalid yandex key: %w", err)
+	}
+	if len(keyBytes) != 16 {
+		return fmt.Errorf("invalid yandex key length: %d", len(keyBytes))
+	}
+	block, err := aes.NewCipher(keyBytes)
+	if err != nil {
+		return err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, sourceURL, nil)
+	if err != nil {
+		return err
+	}
+	resp, err := d.http.Do(req)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = resp.Body.Close() }()
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("download failed: status=%d", resp.StatusCode)
+	}
+	out, err := os.Create(outputPath)
+	if err != nil {
+		return err
+	}
+	success := false
+	defer func() {
+		_ = out.Close()
+		if !success {
+			_ = os.Remove(outputPath)
+		}
+	}()
+
+	var bar *mpb.Bar
+	if d.ProgressEnabled() {
+		d.barStarted.Store(1)
+		desc := shortenName(filepath.Base(outputPath), 54)
+		if resp.ContentLength > 0 {
+			bar = d.progress.AddBar(
+				resp.ContentLength,
+				mpb.PrependDecorators(
+					decor.Name(desc+" ", decor.WC{W: 56, C: decor.DSyncWidth | decor.DindentRight}),
+					decor.Percentage(decor.WCSyncWidthR),
+				),
+				mpb.AppendDecorators(
+					decor.CountersKibiByte("% .1f / % .1f", decor.WCSyncWidthR),
+					decor.Name(" | ", decor.WCSyncWidth),
+					decor.AverageSpeed(decor.SizeB1024(0), "% .1f", decor.WCSyncWidthR),
+					decor.Name(" | ETA ", decor.WCSyncWidth),
+					decor.AverageETA(decor.ET_STYLE_GO, decor.WCSyncWidthR),
+				),
+				mpb.BarRemoveOnComplete(),
+			)
+		} else {
+			bar = d.progress.AddSpinner(
+				0,
+				mpb.PrependDecorators(
+					decor.Name(desc+" ", decor.WC{W: 56, C: decor.DSyncWidth | decor.DindentRight}),
+				),
+				mpb.AppendDecorators(
+					decor.CurrentKibiByte("% .1f", decor.WCSyncWidthR),
+					decor.Name(" | ", decor.WCSyncWidth),
+					decor.Elapsed(decor.ET_STYLE_GO, decor.WCSyncWidthR),
+				),
+				mpb.BarRemoveOnComplete(),
+			)
+			defer bar.SetTotal(-1, true)
+		}
+		defer func() {
+			if !success && bar != nil {
+				bar.Abort(true)
+			}
+		}()
+	}
+
+	stream := cipher.NewCTR(block, make([]byte, aes.BlockSize))
+	reader := &cipher.StreamReader{S: stream, R: resp.Body}
+	buf := make([]byte, downloadBufferSize)
+	totalWritten := int64(0)
+	for {
+		n, readErr := reader.Read(buf)
+		if n > 0 {
+			if _, writeErr := out.Write(buf[:n]); writeErr != nil {
+				return writeErr
+			}
+			totalWritten += int64(n)
+			if bar != nil {
+				bar.IncrBy(n)
+			}
+		}
+		if readErr != nil {
+			if readErr == io.EOF {
+				break
+			}
+			return readErr
+		}
+	}
+	if resp.ContentLength > 0 && totalWritten != resp.ContentLength {
+		return io.ErrUnexpectedEOF
+	}
+	if err = out.Sync(); err != nil {
+		return err
+	}
+	success = true
+	return nil
+}
+
 func (d *Downloader) file(ctx context.Context, sourceURL, outputPath string, allowProgress bool, includeVideo bool) error {
 	logDownloadStart(sourceURL, outputPath)
 	if err := os.MkdirAll(filepath.Dir(outputPath), 0o755); err != nil {