feat(protocol/http, mcpserver, download): add checksum verification, MCP speed tool, pause webhook, and CLI flags (#1542)

pkg/protocol/http/model.go

@@ -1,11 +1,83 @@
 package http
 
+import (
+	"encoding/hex"
+	"fmt"
+	"strings"
+)
+
 type ReqExtra struct {
 	Method string            `json:"method"`
 	Header map[string]string `json:"header"`
 	Body   string            `json:"body"`
 }
 
+// ChecksumOption specifies an expected checksum to verify against
+// the completed download. Only supported for HTTP downloads.
+type ChecksumOption struct {
+	Algorithm string `json:"algorithm"` // "md5" | "sha1" | "sha256"
+	Expected  string `json:"expected"`  // hex-encoded expected hash
+}
+
+// IsEmpty returns true when chk is nil, or when both Algorithm and Expected
+// are blank after trimming whitespace.
+func (chk *ChecksumOption) IsEmpty() bool {
+	if chk == nil {
+		return true
+	}
+	return strings.TrimSpace(chk.Algorithm) == "" && strings.TrimSpace(chk.Expected) == ""
+}
+
+// NormalizedAlgorithm returns the canonical lower-cased algorithm ("md5", "sha1", "sha256")
+// and true if recognized, or ("", false) if unsupported.
+func (chk *ChecksumOption) NormalizedAlgorithm() (string, bool) {
+	if chk == nil {
+		return "", false
+	}
+	switch strings.ToLower(strings.TrimSpace(chk.Algorithm)) {
+	case "md5":
+		return "md5", true
+	case "sha1", "sha-1":
+		return "sha1", true
+	case "sha256", "sha-256":
+		return "sha256", true
+	default:
+		return "", false
+	}
+}
+
+// Validate checks whether the checksum option is valid.
+// Empty options return nil (no verification).
+func (chk *ChecksumOption) Validate() error {
+	if chk.IsEmpty() {
+		return nil
+	}
+	algo, ok := chk.NormalizedAlgorithm()
+	if !ok {
+		return fmt.Errorf("unsupported checksum algorithm: %s", chk.Algorithm)
+	}
+	expected := strings.TrimSpace(chk.Expected)
+	if expected == "" {
+		return fmt.Errorf("checksum expected hash is required when algorithm is set")
+	}
+	var expectedLen int
+	switch algo {
+	case "md5":
+		expectedLen = 32
+	case "sha1":
+		expectedLen = 40
+	case "sha256":
+		expectedLen = 64
+	}
+	if len(expected) != expectedLen {
+		return fmt.Errorf("invalid checksum hash length for %s: expected %d characters, got %d", algo, expectedLen, len(expected))
+	}
+	if _, err := hex.DecodeString(expected); err != nil {
+		return fmt.Errorf("invalid checksum hash for %s: expected valid hexadecimal string", algo)
+	}
+	return nil
+}
+
 type OptsExtra struct {
 	Connections int `json:"connections"`
 	// AutoTorrent when task download complete, and it is a .torrent file, it will be auto create a new task for the torrent file
@@ -21,6 +93,8 @@ type OptsExtra struct {
 	ArchivePassword string `json:"archivePassword"`
 	// DeleteAfterExtract when true, deletes the archive file after successful extraction
 	DeleteAfterExtract bool `json:"deleteAfterExtract"`
+	// Checksum verifies the completed file against an expected hash after download
+	Checksum *ChecksumOption `json:"checksum,omitempty"`
 }
 
 // Stats for download