feat(webdav): support oc:checksums (#8064 close #7472)

Ref: #7472

Author: shniubobo

pkg/utils/hash.go

@@ -10,6 +10,7 @@ import (
 	"errors"
 	"hash"
 	"io"
+	"iter"
 
 	"github.com/alist-org/alist/v3/internal/errs"
 	log "github.com/sirupsen/logrus"
@@ -226,3 +227,13 @@ func (hi HashInfo) GetHash(ht *HashType) string {
 func (hi HashInfo) Export() map[*HashType]string {
 	return hi.h
 }
+
+func (hi HashInfo) All() iter.Seq2[*HashType, string] {
+	return func(yield func(*HashType, string) bool) {
+		for hashType, hashValue := range hi.h {
+			if !yield(hashType, hashValue) {
+				return
+			}
+		}
+	}
+}

server/webdav/prop.go

@@ -9,6 +9,7 @@ import (
 	"context"
 	"encoding/xml"
 	"errors"
+	"fmt"
 	"mime"
 	"net/http"
 	"path"
@@ -101,7 +102,7 @@ type DeadPropsHolder interface {
 	Patch([]Proppatch) ([]Propstat, error)
 }
 
-// liveProps contains all supported, protected DAV: properties.
+// liveProps contains all supported properties.
 var liveProps = map[xml.Name]struct {
 	// findFn implements the propfind function of this property. If nil,
 	// it indicates a hidden property.
@@ -160,6 +161,10 @@ var liveProps = map[xml.Name]struct {
 		findFn: findSupportedLock,
 		dir:    true,
 	},
+	{Space: "http://owncloud.org/ns", Local: "checksums"}: {
+		findFn: findChecksums,
+		dir:    false,
+	},
 }
 
 // TODO(nigeltao) merge props and allprop?
@@ -483,3 +488,11 @@ func findSupportedLock(ctx context.Context, ls LockSystem, name string, fi model
 		`<D:locktype><D:write/></D:locktype>` +
 		`</D:lockentry>`, nil
 }
+
+func findChecksums(ctx context.Context, ls LockSystem, name string, fi model.Obj) (string, error) {
+	checksums := ""
+	for hashType, hashValue := range fi.GetHash().All() {
+		checksums += fmt.Sprintf("<checksum>%s:%s</checksum>", hashType.Name, hashValue)
+	}
+	return checksums, nil
+}