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 {

internal/download/downloader_test.go

@@ -2,8 +2,10 @@ package download
 
 import (
 	"context"
+	"crypto/aes"
 	"crypto/cipher"
 	"errors"
+	"encoding/hex"
 	"io"
 	"net/http"
 	"net/http/httptest"
@@ -110,6 +112,45 @@ func TestFileDeezerEncrypted(t *testing.T) {
 	}
 }
 
+func TestFileYandexEncrypted(t *testing.T) {
+	plain := make([]byte, 8192+333)
+	for i := range plain {
+		plain[i] = byte((i * 11) % 251)
+	}
+	keyHex := "00112233445566778899aabbccddeeff"
+	key, err := hex.DecodeString(keyHex)
+	if err != nil {
+		t.Fatalf("DecodeString() error = %v", err)
+	}
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		t.Fatalf("NewCipher() error = %v", err)
+	}
+	enc := make([]byte, len(plain))
+	copy(enc, plain)
+	stream := cipher.NewCTR(block, make([]byte, aes.BlockSize))
+	stream.XORKeyStream(enc, enc)
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = w.Write(enc)
+	}))
+	defer ts.Close()
+
+	d := NewWithOptions(true, false, 0)
+	out := filepath.Join(t.TempDir(), "x", "a.m4a")
+	if err = d.FileYandexEncrypted(context.Background(), ts.URL, out, keyHex); err != nil {
+		t.Fatalf("FileYandexEncrypted() error = %v", err)
+	}
+
+	got, err := os.ReadFile(out)
+	if err != nil {
+		t.Fatalf("ReadFile() error = %v", err)
+	}
+	if string(got) != string(plain) {
+		t.Fatalf("decrypted file mismatch")
+	}
+}
+
 func TestDownloaderFileTruncatedResponseRemovesPartialFile(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		w.Header().Set("Content-Length", "10")
@@ -160,6 +201,15 @@ func TestFileDeezerEncryptedBadStatus(t *testing.T) {
 	}
 }
 
+func TestFileYandexEncryptedBadKey(t *testing.T) {
+	d := NewWithOptions(true, false, 0)
+	out := filepath.Join(t.TempDir(), "x", "a.m4a")
+	err := d.FileYandexEncrypted(context.Background(), "https://example.com/file", out, "abcd")
+	if err == nil || !strings.Contains(err.Error(), "invalid yandex key length") {
+		t.Fatalf("expected key length error, got %v", err)
+	}
+}
+
 func TestDownloaderFileContextCancellationRemovesPartialFile(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "application/octet-stream")