serve sftp: add support for more hashes (crc32, sha256, blake3, xxh3, xxh128)

backend/sftp/sftp.go

@@ -1756,12 +1756,11 @@ func (f *Fs) Hashes() hash.Set {
 			&f.opt.Xxh3sumCommand,
 			"2d06800538d394c2",
 			[]struct{ hashFile, hashEmpty string }{
-				// The xxhsum tool uses an alternative BSD style output format for the 64-bit variant of XXH3,
+				// The xxhsum tool uses a non-standard prefix "XXH3_" preceding the hash output for the 64-bit variant
-				// otherwise optional with argument --tag, to avoid confusion with the older 64-bit algorithm XXH64.
+				// of XXH3, to avoid confusion with the older 64-bit algorithm XXH64. This was introduced in version
-				// For the same reason there is no algorithm-specific alias, xxh3sum, either. We are currently not able
+				// 0.8.3 released Dec 30, 2024. Older versions only supported the alternative BSD style output format,
-				// to parse this output format. Next release of xxHash after 0.8.2 will change to GNU style, classic
+				// otherwise optional with argument --tag. We are currently not expecting these output formats and can
-				// md5sum, output format, but will use a non-standard prefix "XXH3_" preceding the hash, so we still
+				// therefore not use the "xxhsum -H3" command or its xxh3sum alias directly.
-				// need additional changes to be able to support it.
 				//{"xxh3sum", "xxh3sum"},
 				//{"xxhsum -H3", "xxhsum -H3"},
 				{"rclone hashsum xxh3", "rclone hashsum xxh3"},

cmd/serve/sftp/connection.go

@@ -95,12 +95,44 @@ func (c *conn) execCommand(ctx context.Context, out io.Writer, command string) (
 		if err != nil {
 			return fmt.Errorf("send output failed: %w", err)
 		}
-	case "md5sum", "sha1sum":
+	case "md5sum":
-		ht := hash.MD5
+		return c.handleHashsumCommand(ctx, out, hash.MD5, args)
-		if binary == "sha1sum" {
+	case "sha1sum":
-			ht = hash.SHA1
+		return c.handleHashsumCommand(ctx, out, hash.SHA1, args)
+	case "crc32":
+		return c.handleHashsumCommand(ctx, out, hash.CRC32, args)
+	case "sha256sum":
+		return c.handleHashsumCommand(ctx, out, hash.SHA256, args)
+	case "b3sum":
+		return c.handleHashsumCommand(ctx, out, hash.BLAKE3, args)
+	case "xxh128sum":
+		return c.handleHashsumCommand(ctx, out, hash.XXH128, args)
+	case "xxhsum":
+		argv := strings.SplitN(args, " ", 2)
+		if len(argv) == 0 || argv[0] != "-H2" {
+			return fmt.Errorf("%q not implemented", command)
+		}
+		if len(argv) > 1 {
+			args = argv[1]
+		} else {
+			args = ""
+		}
+		return c.handleHashsumCommand(ctx, out, hash.XXH128, args)
+	case "rclone":
+		argv := strings.SplitN(args, " ", 3)
+		if len(argv) > 1 && argv[0] == "hashsum" {
+			var ht hash.Type
+			if err := ht.Set(argv[1]); err != nil {
+				return err
+			}
+			if len(argv) > 2 {
+				args = argv[2]
+			} else {
+				args = ""
 			}
 			return c.handleHashsumCommand(ctx, out, ht, args)
+		}
+		return fmt.Errorf("%q not implemented", command)
 	case "echo":
 		// Special cases for legacy rclone command detection.
 		// Before rclone v1.49.0 the sftp backend used "echo 'abc' | md5sum" when
@@ -148,10 +180,23 @@ func (c *conn) handleHashsumCommand(ctx context.Context, out io.Writer, ht hash.
 	var hashSum string
 	if args == "" {
 		// empty hash for no input
-		if ht == hash.MD5 {
+		switch ht {
+		case hash.MD5:
 			hashSum = "d41d8cd98f00b204e9800998ecf8427e"
-		} else {
+		case hash.SHA1:
 			hashSum = "da39a3ee5e6b4b0d3255bfef95601890afd80709"
+		case hash.CRC32:
+			hashSum = "00000000"
+		case hash.SHA256:
+			hashSum = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+		case hash.BLAKE3:
+			hashSum = "af1349b9f5f9a1a6a0404dea36dcc9499bcb25c9adc112b7cc9a93cae41f3262"
+		case hash.XXH3:
+			hashSum = "2d06800538d394c2"
+		case hash.XXH128:
+			hashSum = "99aa06d3014798d86001c324468d497f"
+		default:
+			return fmt.Errorf("%v hash not implemented", ht)
 		}
 		args = "-"
 	} else {