webdav: added support for Digest authentication scheme (auto-detected) for server type 'other'.

backend/webdav/webdav.go

@@ -40,6 +40,7 @@ import (
 	"github.com/rclone/rclone/lib/rest"
 
 	ntlmssp "github.com/Azure/go-ntlmssp"
+	"github.com/icholy/digest"
 )
 
 const (
@@ -409,6 +410,24 @@ func (o *Object) filePath() string {
 	return o.fs.filePath(o.remote)
 }
 
+// checkForDigestAuth issues an unauthenticated request to the server to
+// determine if 'Digest' is among the supported authentication schemes.
+// Multiple challenges may be specified in a single response header
+// or provided in separate headers in the same response.
+//
+// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/WWW-Authenticate
+func checkForDigestAuth(url string) bool {
+	resp, err := http.Get(url)
+	if err == nil {
+		for _, challenge := range resp.Header["Www-Authenticate"] {
+			if strings.Contains(challenge, "Digest") {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 // NewFs constructs an Fs from the path, container:path
 func NewFs(ctx context.Context, name, root string, m configmap.Mapper) (fs.Fs, error) {
 	// Parse config into Options struct
@@ -482,6 +501,18 @@ func NewFs(ctx context.Context, name, root string, m configmap.Mapper) (fs.Fs, e
 			rt: ntlmssp.Negotiator{RoundTripper: t},
 		}
 	}
+	if opt.Vendor == "other" {
+		// If available, prefer Digest authentication.
+		if checkForDigestAuth(opt.URL) {
+			fs.Debugf(nil, "using Digest authentication scheme")
+			client.Transport = &digest.Transport{
+				Jar:      client.Jar,
+				Username: opt.User,
+				Password: opt.Pass,
+			}
+		}
+	}
+
 	f.srv = rest.NewClient(client).SetRoot(u.String())
 
 	f.features = (&fs.Features{

go.mod

@@ -222,6 +222,7 @@ require (
 	github.com/Microsoft/go-winio v0.6.1 // indirect
 	github.com/ProtonMail/go-crypto v1.1.3
 	github.com/golang-jwt/jwt/v4 v4.5.1
+	github.com/icholy/digest v1.0.1
 	github.com/pkg/xattr v0.4.10
 	golang.org/x/mobile v0.0.0-20240716161057-1ad2df20a8b6
 	golang.org/x/term v0.27.0

go.sum

@@ -375,6 +375,8 @@ github.com/henrybear327/go-proton-api v1.0.0 h1:zYi/IbjLwFAW7ltCeqXneUGJey0TN//X
 github.com/henrybear327/go-proton-api v1.0.0/go.mod h1:w63MZuzufKcIZ93pwRgiOtxMXYafI8H74D77AxytOBc=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
+github.com/icholy/digest v1.0.1 h1:HBhK5/Ab2Z4rHgw6n5UooxcJpLSeMR+TuD5rkvRc7Z8=
+github.com/icholy/digest v1.0.1/go.mod h1:QNrsSGQ5v7v9cReDI0+eyjsXGUoRSUZQHeQ5C4XLa0Y=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/jcmturner/aescts/v2 v2.0.0 h1:9YKLH6ey7H4eDBXW8khjYslgyqG2xZikXP0EQFKrle8=