chore(deps): update golang.org/x/crypto/x509roots/fallback digest to cdce021 (#341)

Co-authored-by: Henrique Dias <[email protected]>

.github/workflows/build.yml

@@ -12,10 +12,10 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: actions/setup-go@v6
         with:
-          go-version: "1.25.x"
+          go-version: "1.26.x"
       - run: go build .
         env:
           CGO_ENABLED: '0'

.github/workflows/docker.yml

@@ -18,22 +18,22 @@ jobs:
       id-token: write
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
+        uses: docker/setup-qemu-action@v4
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
 
       - name: Log in to Docker Hub
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
 
       - name: Login to GitHub Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
@@ -41,7 +41,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           images: |
             hacdias/webdav
@@ -55,7 +55,7 @@ jobs:
 
       - name: Build and push Docker image
         id: push
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: .
           file: ./Dockerfile

.github/workflows/lint.yml

@@ -12,10 +12,10 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: actions/setup-go@v6
         with:
-          go-version: "1.25.x"
+          go-version: "1.26.x"
       - uses: golangci/golangci-lint-action@v9
         with:
           version: "latest"

.github/workflows/releaser.yml

@@ -12,13 +12,13 @@ jobs:
   goreleaser:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
         with:
           fetch-depth: 0
       - uses: actions/setup-go@v6
         with:
-          go-version: "1.25.x"
-      - uses: goreleaser/goreleaser-action@v6
+          go-version: "1.26.x"
+      - uses: goreleaser/goreleaser-action@v7
         with:
           distribution: goreleaser
           version: '~> v2'

.github/workflows/test.yml

@@ -13,9 +13,9 @@ jobs:
     name: test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: actions/setup-go@v6
         with:
-          go-version: "1.25.x"
+          go-version: "1.26.x"
       - name: Run test with coverage
         run: go test -race -coverprofile=coverage.txt -covermode=atomic ./...

.gitignore

@@ -1,2 +1,2 @@
 dist/
-webdav
+webdav

.goreleaser.yml

@@ -38,9 +38,11 @@ builds:
       - goos: openbsd
         goarch: arm
         goarm: 6
+      # Broken as of Go 1.24, deprecated as of Go 1.26
       - goos: freebsd
         goarch: arm
-        goarm: 6
+      - goos: windows
+        goarch: arm
 
 archives:
   - name_template: "{{.Os}}-{{.Arch}}{{if .Arm}}v{{.Arm}}{{end}}-{{ .ProjectName }}"

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.25-alpine3.22 AS build
+FROM golang:1.26-alpine3.22 AS build
 
 ARG VERSION="untracked"
 

README.md

@@ -38,34 +38,45 @@ docker pull hacdias/webdav:latest
 
 For usage information regarding the CLI, run `webdav --help`.
 
-### Docker
+### Container
 
-To use with Docker, you need to provide a configuration file and mount the data directories. For example, let's take the following configuration file that simply sets the port to `6060` and the directory to `/data`.
+To run the container, you can refer to the `compose.yml` file which provides a minimal setup. Additionally, you also need to create a configuration file, as [explained below](#configuration).
 
-```yaml
-port: 6060
-directory: /data
-```
-
-You can now run with the following Docker command, where you mount the configuration file inside the container, and the data directory too, as well as forwarding the port 6060. You will need to change this to match your own configuration.
+The equivalent Docker command to the aforementioned compose file would be as follows:
 
 ```bash
 docker run \
-  -p 6060:6060 \
-  -v $(pwd)/config.yml:/config.yml:ro \
-  -v $(pwd)/data:/data \
+  -p 6065:6065 \
+  -v ./config.yml:/config.yml:ro \
+  -v ./data:/data \
   ghcr.io/hacdias/webdav -c /config.yml
 ```
 
-If you are using [fail2ban](#fail2ban-setup), it would be helpful to add the parameters listed below. They will assist in analyzing the log.
+If you are using [fail2ban](#fail2ban-setup), it would be helpful to add the parameters listed below. They will assist in analyzing 
+the log.
+
 ```bash
 --log-driver journald \
 --name webdav \
 ```
 
+### Partial updates
+
+This server supports partial file updates compatible with SabreDAV's `PATCH` extension. This is not an official WebDAV specification. Requests must use the `application/x-sabredav-partialupdate` content type, include `Content-Length`, and provide the target range in `X-Update-Range`.
+
+Supported `X-Update-Range` values are:
+
+- `bytes=start-end`
+- `bytes=start-`
+- `bytes=-N`
+- `append`
+
+For clients that use it, the server also supports partial `PUT` requests with `Content-Range`, for example `Content-Range: bytes 6-8/*`. This is an extra compatibility path and should be treated as a client/server agreement.
+
 ## Configuration
 
-The configuration can be provided as a YAML, JSON or TOML file. Below is an example of a YAML configuration file with all the options available, as well as what they mean.
+The configuration can be provided as a YAML, JSON or TOML file. Below is an example of a YAML configuration file with 
+all the options available, as well as what they mean.
 
 ```yaml
 address: 0.0.0.0
@@ -92,8 +103,9 @@ behindProxy: false
 
 # The directory that will be able to be accessed by the users when connecting.
 # This directory will be used by users unless they have their own 'directory' defined.
-# Default is '.' (current directory).
-directory: .
+# By default it points to the working directory. In the case of the compose file above,
+# that is /data.
+directory: /data
 
 # The default permissions for users. This is a case insensitive option. Possible
 # permissions: C (Create), R (Read), U (Update), D (Delete). You can combine multiple
@@ -124,48 +136,67 @@ log:
   colors: true
   # Logging outputs. You can have more than one output. Default is only 'stderr'.
   outputs:
-  - stderr
+    - stderr
 
 # CORS configuration
 cors:
   # Whether or not CORS configuration should be applied. Default is 'false'.
   enabled: true
   credentials: true
-  allowed_headers:
-    - Depth
+  # The following are the default CORS settings when it is enabled.
   allowed_hosts:
-    - http://localhost:8080
-  allowed_methods:
-    - GET
-  exposed_headers:
-    - Content-Length
+    - '*'
+  allowed_headers:
+    - Authorization
+    - Content-Type
     - Content-Range
+    - Depth
+    - Destination
+    - If
+    - Lock-Token
+    - Overwrite
+    - TimeOut
+    - Translate
+    - X-Update-Range
+  allowed_methods:
+    - COPY
+    - DELETE
+    - GET
+    - HEAD
+    - LOCK
+    - UNLOCK
+    - MKCOL
+    - MOVE
+    - OPTIONS
+    - PATCH
+    - POST
+    - PROPFIND
+    - PROPPATCH
+    - PUT
+  exposed_headers: []
 
-# The list of users. If the list is empty, then there will be no authentication.
-# Otherwise, basic authentication will automatically be configured.
-#
-# If you're delegating the authentication to a different service, you can proxy
-# the username using basic authentication, and then disable webdav's password
-# check using the option:
-#
-# noPassword: true
+# You define here the list of users.
+# Basic authentication is automatically be configured when users are detected 
+# below, else there will be no authentication.
+# Customize to your needs and don't forget to comment out the users you don't need.
 users:
   # Example 'admin' user with plaintext password.
   - username: admin
     password: admin
+
   # Example 'john' user with bcrypt encrypted password, with custom directory.
-  # You can generate a bcrypt-encrypted password by using the 'webdav bcrypt'
-  # command lint utility.
+  # Tip: you can generate a bcrypt-encrypted password by using the 'webdav bcrypt'
+  # command lint utility, or htpasswd on Linux.
   - username: john
     password: "{bcrypt}$2y$10$zEP6oofmXFeHaeMfBNLnP.DO8m.H.Mwhd24/TOX2MWLxAExXi4qgi"
-    directory: /another/path
+    directory: /data/john
   # Example user whose details will be picked up from the environment.
   - username: "{env}ENV_USERNAME"
     password: "{env}ENV_PASSWORD"
+  # Example user with advanced control over his permissions
   - username: basic
     password: basic
-    # Override default permissions.
-    permissions: CRUD
+    permissions: CRUD # Override default permissions.
     rules:
       # With this rule, the user CANNOT access {user directory}/some/files.
       - path: /some/file
@@ -178,6 +209,16 @@ users:
       # It uses a regular expression.
       - regex: "^.+.js$"
         permissions: RU
+  # Example user for android SeedVault backuping
+  - username: android
+    password: "{bcrypt}$2y$10$zEP6oofmXFeHaeMfBNLnP.DO8m.H.Mwhd24/TOX2MWLxAExXi4qgi"
+    directory: /data/android
+    permissions: CRUD
+
+# If you're delegating the authentication to a different service, you can proxy
+# the username using basic authentication, and then disable webdav's password
+# check using the option:
+# noPassword: true
 ```
 
 ### CORS
@@ -225,7 +266,8 @@ example.com {
     @hasDest header_regexp dest ^https?://[^/]+(.*)$
     header @hasDest Destination {re.dest.1}
 
-    reverse_proxy 127.0.0.1:6065 { # if running on the same network in docker you can just point to the service name e.g. webdav:6065
+    # if running on the same network in docker you can just point to the service name e.g. webdav:6065
+    reverse_proxy 127.0.0.1:6065 {
         header_up X-Real-IP {remote_host}
         header_up REMOTE-HOST {remote_host}
     }

cmd/root.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"net"
@@ -80,6 +81,8 @@ set WD_CERT.`,
 			return err
 		}
 
+		server := &http.Server{Handler: handler}
+
 		// Trap exiting signals
 		quit := make(chan os.Signal, 1)
 
@@ -88,9 +91,9 @@ set WD_CERT.`,
 
 			var err error
 			if cfg.TLS {
-				err = http.ServeTLS(listener, handler, cfg.Cert, cfg.Key)
+				err = server.ServeTLS(listener, cfg.Cert, cfg.Key)
 			} else {
-				err = http.Serve(listener, handler)
+				err = server.Serve(listener)
 			}
 
 			if err != nil && !errors.Is(err, http.ErrServerClosed) {
@@ -104,7 +107,7 @@ set WD_CERT.`,
 		signal := <-quit
 
 		zap.L().Info("caught signal, shutting down", zap.Stringer("signal", signal))
-		_ = listener.Close()
+		_ = server.Shutdown(context.Background())
 
 		return nil
 	},

compose.yml

@@ -0,0 +1,14 @@
+name: webdav
+
+services:
+  app:
+    container_name: webdav
+    image: 'webdav:test'
+    ports:
+     - '6065:6065'
+    security_opt:
+      - label=type:container_runtime_t
+    restart: always
+    volumes:
+      - ./data:/data
+      - ./config.yml:/config.yml:ro

go.mod

@@ -3,18 +3,18 @@ module github.com/hacdias/webdav/v5
 go 1.25.0
 
 require (
-	github.com/coreos/go-systemd/v22 v22.6.0
+	github.com/coreos/go-systemd/v22 v22.7.0
 	github.com/go-viper/mapstructure/v2 v2.5.0
 	github.com/rs/cors v1.11.1
 	github.com/spf13/cobra v1.10.2
 	github.com/spf13/pflag v1.0.10
 	github.com/spf13/viper v1.21.0
 	github.com/stretchr/testify v1.11.1
-	github.com/studio-b12/gowebdav v0.11.0
-	go.uber.org/zap v1.27.1
-	golang.org/x/crypto v0.47.0
-	golang.org/x/crypto/x509roots/fallback v0.0.0-20260113154411-7d0074ccc6f1
-	golang.org/x/net v0.49.0
+	github.com/studio-b12/gowebdav v0.12.0
+	go.uber.org/zap v1.28.0
+	golang.org/x/crypto v0.53.0
+	golang.org/x/crypto/x509roots/fallback v0.0.0-20260708182226-cdce021fa6c7
+	golang.org/x/net v0.56.0
 )
 
 require (
@@ -30,7 +30,7 @@ require (
 	github.com/subosito/gotenv v1.6.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
-	golang.org/x/sys v0.40.0 // indirect
-	golang.org/x/text v0.33.0 // indirect
+	golang.org/x/sys v0.46.0 // indirect
+	golang.org/x/text v0.38.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,5 +1,5 @@
-github.com/coreos/go-systemd/v22 v22.6.0 h1:aGVa/v8B7hpb0TKl0MWoAavPDmHvobFe5R5zn0bCJWo=
-github.com/coreos/go-systemd/v22 v22.6.0/go.mod h1:iG+pp635Fo7ZmV/j14KUcmEyWF+0X7Lua8rrTWzYgWU=
+github.com/coreos/go-systemd/v22 v22.7.0 h1:LAEzFkke61DFROc7zNLX/WA2i5J8gYqe0rSj9KI28KA=
+github.com/coreos/go-systemd/v22 v22.7.0/go.mod h1:xNUYtjHu2EDXbsxz1i41wouACIwT7Ybq9o0BQhMwD0w=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -43,28 +43,28 @@ github.com/spf13/viper v1.21.0 h1:x5S+0EU27Lbphp4UKm1C+1oQO+rKx36vfCoaVebLFSU=
 github.com/spf13/viper v1.21.0/go.mod h1:P0lhsswPGWD/1lZJ9ny3fYnVqxiegrlNrEmgLjbTCAY=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
-github.com/studio-b12/gowebdav v0.11.0 h1:qbQzq4USxY28ZYsGJUfO5jR+xkFtcnwWgitp4Zp1irU=
-github.com/studio-b12/gowebdav v0.11.0/go.mod h1:bHA7t77X/QFExdeAnDzK6vKM34kEZAcE1OX4MfiwjkE=
+github.com/studio-b12/gowebdav v0.12.0 h1:kFRtQECt8jmVAvA6RHBz3geXUGJHUZA6/IKpOVUs5kM=
+github.com/studio-b12/gowebdav v0.12.0/go.mod h1:bHA7t77X/QFExdeAnDzK6vKM34kEZAcE1OX4MfiwjkE=
 github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
 github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
 go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
-go.uber.org/zap v1.27.1 h1:08RqriUEv8+ArZRYSTXy1LeBScaMpVSTBhCeaZYfMYc=
-go.uber.org/zap v1.27.1/go.mod h1:GB2qFLM7cTU87MWRP2mPIjqfIDnGu+VIO4V/SdhGo2E=
+go.uber.org/zap v1.28.0 h1:IZzaP1Fv73/T/pBMLk4VutPl36uNC+OSUh3JLG3FIjo=
+go.uber.org/zap v1.28.0/go.mod h1:rDLpOi171uODNm/mxFcuYWxDsqWSAVkFdX4XojSKg/Q=
 go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
-golang.org/x/crypto v0.47.0 h1:V6e3FRj+n4dbpw86FJ8Fv7XVOql7TEwpHapKoMJ/GO8=
-golang.org/x/crypto v0.47.0/go.mod h1:ff3Y9VzzKbwSSEzWqJsJVBnWmRwRSHt/6Op5n9bQc4A=
-golang.org/x/crypto/x509roots/fallback v0.0.0-20260113154411-7d0074ccc6f1 h1:EBHQuS9qI8xJ96+YRgVV2ahFLUYbWpt1rf3wPfXN2wQ=
-golang.org/x/crypto/x509roots/fallback v0.0.0-20260113154411-7d0074ccc6f1/go.mod h1:MEIPiCnxvQEjA4astfaKItNwEVZA5Ki+3+nyGbJ5N18=
-golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
-golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
-golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
-golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
-golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
-golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
+golang.org/x/crypto v0.53.0 h1:QZ4Muo8THX6CizN2vPPd5fBGHyogrdK9fG4wLPFUsto=
+golang.org/x/crypto v0.53.0/go.mod h1:DNLU434OwVakk9PzuwV8w62mAJpRJL3vsgcfp4Qnsio=
+golang.org/x/crypto/x509roots/fallback v0.0.0-20260708182226-cdce021fa6c7 h1:XWbcG8uLNW2EmI8DBzFXp7XwIxmrYK6s7ME2iyyq7Cg=
+golang.org/x/crypto/x509roots/fallback v0.0.0-20260708182226-cdce021fa6c7/go.mod h1:+UoQFNBq2p2wO+Q6ddVtYc25GZ6VNdOMyyrd4nrqrKs=
+golang.org/x/net v0.56.0 h1:Rw8j/hFzGvJUZwNBXnAtf5sVDVt+65SK2C7IxCxZt5o=
+golang.org/x/net v0.56.0/go.mod h1:D3Ku6r+V6JROoZK144D2XfMHFcMq/0zSfLelVTCFKec=
+golang.org/x/sys v0.46.0 h1:noSf2Fq6F8DBgS+LysIkx7rIExoNHJsxOAtPp4rthXw=
+golang.org/x/sys v0.46.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/text v0.38.0 h1:sXmwo9DwP3OK9EZ7PqAdaooSGozfl/3a6/xJcbzPRhE=
+golang.org/x/text v0.38.0/go.mod h1:YXZt3QhHUKYT53r2lLKFIVi6Ao1jdzrTR/KQ09qyxF4=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

lib/config.go

@@ -86,9 +86,9 @@ func ParseConfig(filename string, flags *pflag.FlagSet) (*Config, error) {
 	v.SetDefault("Log.Format", "console")
 	v.SetDefault("Log.Outputs", []string{"stderr"})
 	v.SetDefault("Log.Colors", true)
-	v.SetDefault("CORS.Allowed_Headers", []string{"*"})
 	v.SetDefault("CORS.Allowed_Hosts", []string{"*"})
-	v.SetDefault("CORS.Allowed_Methods", []string{"*"})
+	v.SetDefault("CORS.Allowed_Headers", []string{"Authorization", "Content-Type", "Content-Range", "Depth", "Destination", "If", "Lock-Token", "Overwrite", "X-Update-Range"})
+	v.SetDefault("CORS.Allowed_Methods", []string{"COPY", "DELETE", "GET", "HEAD", "LOCK", "MKCOL", "MOVE", "OPTIONS", "PATCH", "POST", "PROPFIND", "PROPPATCH", "PUT", "UNLOCK"})
 
 	// Read and unmarshal configuration
 	err := v.ReadInConfig()

lib/config_test.go

@@ -51,9 +51,9 @@ func TestConfigDefaults(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, dir, cfg.Directory)
 
-	require.EqualValues(t, []string{"*"}, cfg.CORS.AllowedHeaders)
 	require.EqualValues(t, []string{"*"}, cfg.CORS.AllowedHosts)
-	require.EqualValues(t, []string{"*"}, cfg.CORS.AllowedMethods)
+	require.EqualValues(t, []string{"Authorization", "Content-Type", "Content-Range", "Depth", "Destination", "If", "Lock-Token", "Overwrite", "X-Update-Range"}, cfg.CORS.AllowedHeaders)
+	require.EqualValues(t, []string{"COPY", "DELETE", "GET", "HEAD", "LOCK", "MKCOL", "MOVE", "OPTIONS", "PATCH", "POST", "PROPFIND", "PROPPATCH", "PUT", "UNLOCK"}, cfg.CORS.AllowedMethods)
 }
 
 func TestConfigCascade(t *testing.T) {

lib/handler.go

@@ -176,6 +176,16 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	if r.Method == "OPTIONS" {
+		user.handleOptions(w, r, req.path)
+		return
+	}
+
+	if r.Method == "PATCH" || (r.Method == "PUT" && r.Header.Get("Content-Range") != "") {
+		user.handlePartialUpdate(w, r, req.path)
+		return
+	}
+
 	// Runs the WebDAV.
 	user.ServeHTTP(w, r)
 }

lib/handler_test.go

@@ -2,10 +2,13 @@ package lib
 
 import (
 	"fmt"
+	"io"
+	"net/http"
 	"net/http/httptest"
 	"os"
 	"path/filepath"
 	"sort"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -82,6 +85,404 @@ func TestServerDefaults(t *testing.T) {
 	require.ErrorContains(t, client.Write("/foo.txt", []byte("hello world 2"), 0666), "403")
 }
 
+func TestServerPartialUpdateOptions(t *testing.T) {
+	t.Parallel()
+
+	dir := makeTestDirectory(t, map[string][]byte{
+		"foo.txt": []byte("hello world"),
+	})
+	srv := makeTestServer(t, "directory: "+dir+"\npermissions: CRUD")
+	defer srv.Close()
+
+	req, err := http.NewRequest(http.MethodOptions, srv.URL+"/foo.txt", nil)
+	require.NoError(t, err)
+	resp, err := http.DefaultClient.Do(req)
+	require.NoError(t, err)
+	defer func() { _ = resp.Body.Close() }()
+
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+	require.Contains(t, resp.Header.Get("DAV"), "sabredav-partialupdate")
+	require.Contains(t, resp.Header.Get("Allow"), "PATCH")
+	require.Equal(t, partialUpdateContentType, resp.Header.Get("Accept-Patch"))
+}
+
+func TestServerPatchPartialUpdate(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name        string
+		initialData string
+		body        string
+		updateRange string
+		wantData    string
+	}{{
+		name:        "start",
+		initialData: "hello world",
+		body:        "DAV",
+		updateRange: "bytes=6-",
+		wantData:    "hello DAVld",
+	}, {
+		name:        "suffix",
+		initialData: "hello world",
+		body:        "DAV",
+		updateRange: "bytes=-5",
+		wantData:    "hello DAVld",
+	}, {
+		name:        "append",
+		initialData: "hello",
+		body:        " world",
+		updateRange: "append",
+		wantData:    "hello world",
+	}, {
+		name:        "suffix_zero",
+		initialData: "hello",
+		body:        " world",
+		updateRange: "bytes=-0",
+		wantData:    "hello world",
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			dir := makeTestDirectory(t, map[string][]byte{
+				"foo.txt": []byte(tc.initialData),
+			})
+			srv := makeTestServer(t, "directory: "+dir+"\npermissions: CRUD")
+			defer srv.Close()
+
+			req, err := http.NewRequest("PATCH", srv.URL+"/foo.txt", strings.NewReader(tc.body))
+			require.NoError(t, err)
+			req.Header.Set("Content-Type", partialUpdateContentType)
+			req.Header.Set("X-Update-Range", tc.updateRange)
+			resp, err := http.DefaultClient.Do(req)
+			require.NoError(t, err)
+			defer func() { _ = resp.Body.Close() }()
+
+			require.Equal(t, http.StatusNoContent, resp.StatusCode)
+			data, err := os.ReadFile(filepath.Join(dir, "foo.txt"))
+			require.NoError(t, err)
+			require.Equal(t, tc.wantData, string(data))
+		})
+	}
+}
+
+func TestServerPatchPartialUpdateCreatesSparseFile(t *testing.T) {
+	t.Parallel()
+
+	dir := makeTestDirectory(t, nil)
+	srv := makeTestServer(t, "directory: "+dir+"\npermissions: CRUD")
+	defer srv.Close()
+
+	req, err := http.NewRequest("PATCH", srv.URL+"/new.bin", strings.NewReader("x"))
+	require.NoError(t, err)
+	req.Header.Set("Content-Type", partialUpdateContentType)
+	req.Header.Set("X-Update-Range", "bytes=3-")
+	resp, err := http.DefaultClient.Do(req)
+	require.NoError(t, err)
+	defer func() { _ = resp.Body.Close() }()
+
+	require.Equal(t, http.StatusCreated, resp.StatusCode)
+	data, err := os.ReadFile(filepath.Join(dir, "new.bin"))
+	require.NoError(t, err)
+	require.Equal(t, []byte{0, 0, 0, 'x'}, data)
+}
+
+func TestServerPutContentRangePartialUpdate(t *testing.T) {
+	t.Parallel()
+
+	dir := makeTestDirectory(t, map[string][]byte{
+		"foo.txt": []byte("hello world"),
+	})
+	srv := makeTestServer(t, "directory: "+dir+"\npermissions: CRUD")
+	defer srv.Close()
+
+	req, err := http.NewRequest(http.MethodPut, srv.URL+"/foo.txt", strings.NewReader("DAV"))
+	require.NoError(t, err)
+	req.Header.Set("Content-Range", "bytes 6-8/*")
+	resp, err := http.DefaultClient.Do(req)
+	require.NoError(t, err)
+	defer func() { _ = resp.Body.Close() }()
+	_, _ = io.Copy(io.Discard, resp.Body)
+
+	require.Equal(t, http.StatusNoContent, resp.StatusCode)
+	data, err := os.ReadFile(filepath.Join(dir, "foo.txt"))
+	require.NoError(t, err)
+	require.Equal(t, "hello DAVld", string(data))
+}
+
+func TestServerPartialUpdateErrors(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name          string
+		method        string
+		body          string
+		contentLength int64
+		path          string
+		headerName    string
+		updateRange   string
+		contentRange  string
+		wantStatus    int
+	}{{
+		name:          "patch_missing_content_length",
+		method:        "PATCH",
+		body:          "DAV",
+		contentLength: -1,
+		updateRange:   "bytes=6-8",
+		wantStatus:    http.StatusLengthRequired,
+	}, {
+		name:        "patch_invalid_range",
+		method:      "PATCH",
+		body:        "DAV",
+		updateRange: "bytes=8-6",
+		wantStatus:  http.StatusRequestedRangeNotSatisfiable,
+	}, {
+		name:        "patch_length_mismatch",
+		method:      "PATCH",
+		body:        "TOOLONG",
+		updateRange: "bytes=6-8",
+		wantStatus:  http.StatusRequestedRangeNotSatisfiable,
+	}, {
+		name:          "put_content_range_length_mismatch",
+		method:        http.MethodPut,
+		body:          "TOOLONG",
+		contentLength: -1,
+		contentRange:  "bytes 6-8/*",
+		wantStatus:    http.StatusRequestedRangeNotSatisfiable,
+	}, {
+		name:        "if_none_match",
+		method:      "PATCH",
+		body:        "DAV",
+		headerName:  "If-None-Match",
+		updateRange: "bytes=0-2",
+		wantStatus:  http.StatusPreconditionFailed,
+	}, {
+		name:        "if_match",
+		method:      "PATCH",
+		path:        "/missing.txt",
+		body:        "DAV",
+		headerName:  "If-Match",
+		updateRange: "bytes=0-2",
+		wantStatus:  http.StatusPreconditionFailed,
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			dir := makeTestDirectory(t, map[string][]byte{
+				"foo.txt": []byte("hello world"),
+			})
+			srv := makeTestServer(t, "directory: "+dir+"\npermissions: CRUD")
+			defer srv.Close()
+
+			var body io.Reader = strings.NewReader(tc.body)
+			if tc.contentLength < 0 {
+				body = io.NopCloser(strings.NewReader(tc.body))
+			}
+			path := tc.path
+			if path == "" {
+				path = "/foo.txt"
+			}
+			req, err := http.NewRequest(tc.method, srv.URL+path, body)
+			require.NoError(t, err)
+			if tc.contentLength < 0 {
+				req.ContentLength = tc.contentLength
+			}
+			if tc.method == "PATCH" {
+				req.Header.Set("Content-Type", partialUpdateContentType)
+				req.Header.Set("X-Update-Range", tc.updateRange)
+			}
+			if tc.contentRange != "" {
+				req.Header.Set("Content-Range", tc.contentRange)
+			}
+			if tc.headerName != "" {
+				req.Header.Set(tc.headerName, "*")
+			}
+			resp, err := http.DefaultClient.Do(req)
+			require.NoError(t, err)
+			defer func() { _ = resp.Body.Close() }()
+
+			require.Equal(t, tc.wantStatus, resp.StatusCode)
+			data, err := os.ReadFile(filepath.Join(dir, "foo.txt"))
+			require.NoError(t, err)
+			require.Equal(t, "hello world", string(data))
+		})
+	}
+}
+
+func TestServerPartialUpdateETagPreconditions(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name         string
+		method       string
+		headerName   string
+		headerValue  func(string) string
+		contentRange string
+		wantStatus   int
+		wantData     string
+	}{{
+		name:        "if_match_matches",
+		method:      "PATCH",
+		headerName:  "If-Match",
+		headerValue: func(etag string) string { return etag },
+		wantStatus:  http.StatusNoContent,
+		wantData:    "hello DAVld",
+	}, {
+		name:        "if_match_mismatch",
+		method:      "PATCH",
+		headerName:  "If-Match",
+		headerValue: func(string) string { return `"definitely-wrong"` },
+		wantStatus:  http.StatusPreconditionFailed,
+		wantData:    "hello world",
+	}, {
+		name:        "if_match_list_matches",
+		method:      "PATCH",
+		headerName:  "If-Match",
+		headerValue: func(etag string) string { return `"definitely-wrong", ` + etag },
+		wantStatus:  http.StatusNoContent,
+		wantData:    "hello DAVld",
+	}, {
+		name:        "if_none_match_matches",
+		method:      "PATCH",
+		headerName:  "If-None-Match",
+		headerValue: func(etag string) string { return etag },
+		wantStatus:  http.StatusPreconditionFailed,
+		wantData:    "hello world",
+	}, {
+		name:        "if_none_match_mismatch",
+		method:      "PATCH",
+		headerName:  "If-None-Match",
+		headerValue: func(string) string { return `"definitely-wrong"` },
+		wantStatus:  http.StatusNoContent,
+		wantData:    "hello DAVld",
+	}, {
+		name:         "put_content_range_if_match_mismatch",
+		method:       http.MethodPut,
+		headerName:   "If-Match",
+		headerValue:  func(string) string { return `"definitely-wrong"` },
+		contentRange: "bytes 6-8/*",
+		wantStatus:   http.StatusPreconditionFailed,
+		wantData:     "hello world",
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			dir := makeTestDirectory(t, map[string][]byte{
+				"foo.txt": []byte("hello world"),
+			})
+			srv := makeTestServer(t, "directory: "+dir+"\npermissions: CRUD")
+			defer srv.Close()
+
+			req, err := http.NewRequest(http.MethodHead, srv.URL+"/foo.txt", nil)
+			require.NoError(t, err)
+			resp, err := http.DefaultClient.Do(req)
+			require.NoError(t, err)
+			_ = resp.Body.Close()
+			require.Equal(t, http.StatusOK, resp.StatusCode)
+			etag := resp.Header.Get("ETag")
+			require.NotEmpty(t, etag)
+
+			req, err = http.NewRequest(tc.method, srv.URL+"/foo.txt", strings.NewReader("DAV"))
+			require.NoError(t, err)
+			if tc.method == "PATCH" {
+				req.Header.Set("Content-Type", partialUpdateContentType)
+				req.Header.Set("X-Update-Range", "bytes=6-8")
+			}
+			if tc.contentRange != "" {
+				req.Header.Set("Content-Range", tc.contentRange)
+			}
+			req.Header.Set(tc.headerName, tc.headerValue(etag))
+			resp, err = http.DefaultClient.Do(req)
+			require.NoError(t, err)
+			defer func() { _ = resp.Body.Close() }()
+
+			require.Equal(t, tc.wantStatus, resp.StatusCode)
+			data, err := os.ReadFile(filepath.Join(dir, "foo.txt"))
+			require.NoError(t, err)
+			require.Equal(t, tc.wantData, string(data))
+		})
+	}
+}
+
+func TestServerPartialUpdateHonorsLocks(t *testing.T) {
+	t.Parallel()
+
+	const createLockBody = `<?xml version="1.0" encoding="utf-8" ?>
+		<D:lockinfo xmlns:D='DAV:'>
+			<D:lockscope><D:exclusive/></D:lockscope>
+			<D:locktype><D:write/></D:locktype>
+			<D:owner>test</D:owner>
+		</D:lockinfo>`
+
+	testCases := []struct {
+		name     string
+		lockPath string
+		depth    string
+		ifPath   string
+	}{{
+		name:     "file",
+		lockPath: "/foo.txt",
+		depth:    "0",
+		ifPath:   "/foo.txt",
+	}, {
+		name:     "root",
+		lockPath: "/",
+		depth:    "infinity",
+		ifPath:   "/",
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			dir := makeTestDirectory(t, map[string][]byte{
+				"foo.txt": []byte("hello world"),
+			})
+			srv := makeTestServer(t, "directory: "+dir+"\npermissions: CRUD")
+			defer srv.Close()
+
+			req, err := http.NewRequest("LOCK", srv.URL+tc.lockPath, strings.NewReader(createLockBody))
+			require.NoError(t, err)
+			req.Header.Set("Content-Type", "application/xml")
+			req.Header.Set("Depth", tc.depth)
+			resp, err := http.DefaultClient.Do(req)
+			require.NoError(t, err)
+			defer func() { _ = resp.Body.Close() }()
+			_, _ = io.Copy(io.Discard, resp.Body)
+			require.Equal(t, http.StatusOK, resp.StatusCode)
+			lockToken := resp.Header.Get("Lock-Token")
+
+			req, err = http.NewRequest("PATCH", srv.URL+"/foo.txt", strings.NewReader("DAV"))
+			require.NoError(t, err)
+			req.Header.Set("Content-Type", partialUpdateContentType)
+			req.Header.Set("X-Update-Range", "bytes=6-8")
+			resp, err = http.DefaultClient.Do(req)
+			require.NoError(t, err)
+			defer func() { _ = resp.Body.Close() }()
+			require.Equal(t, 423, resp.StatusCode)
+
+			req, err = http.NewRequest("PATCH", srv.URL+"/foo.txt", strings.NewReader("DAV"))
+			require.NoError(t, err)
+			req.Header.Set("Content-Type", partialUpdateContentType)
+			req.Header.Set("X-Update-Range", "bytes=6-8")
+			req.Header.Set("If", fmt.Sprintf("<%s%s> (%s)", srv.URL, tc.ifPath, lockToken))
+			resp, err = http.DefaultClient.Do(req)
+			require.NoError(t, err)
+			defer func() { _ = resp.Body.Close() }()
+			require.Equal(t, http.StatusNoContent, resp.StatusCode)
+
+			data, err := os.ReadFile(filepath.Join(dir, "foo.txt"))
+			require.NoError(t, err)
+			require.Equal(t, "hello DAVld", string(data))
+		})
+	}
+}
+
 func TestServerListingCharacters(t *testing.T) {
 	t.Parallel()
 
@@ -290,6 +691,12 @@ users:
 
 	err = client.Write("/c/b.txt", []byte("new"), 0666)
 	require.ErrorContains(t, err, "403")
+
+	err = client.MkdirAll("/d/foo/bar", 0666)
+	require.NoError(t, err)
+
+	err = client.Write("/d/foo/bar/test.txt", []byte("test"), 0666)
+	require.NoError(t, err)
 }
 
 func TestServerRulesAdditive(t *testing.T) {

lib/partial_update.go

@@ -0,0 +1,526 @@
+package lib
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"mime"
+	"net/http"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"golang.org/x/net/webdav"
+)
+
+const partialUpdateContentType = "application/x-sabredav-partialupdate"
+
+type updateRange struct {
+	offset int64
+	end    int64
+	hasEnd bool
+	append bool
+}
+
+type partialUpdateError struct {
+	status int
+	err    error
+}
+
+func (e partialUpdateError) Error() string {
+	return e.err.Error()
+}
+
+func newPartialUpdateError(status int, message string) error {
+	return partialUpdateError{status: status, err: errors.New(message)}
+}
+
+func writePartialUpdateError(w http.ResponseWriter, err error, fallbackStatus int) {
+	var httpErr partialUpdateError
+	if errors.As(err, &httpErr) {
+		fallbackStatus = httpErr.status
+	}
+	http.Error(w, err.Error(), fallbackStatus)
+}
+
+func (u *handlerUser) handleOptions(w http.ResponseWriter, r *http.Request, reqPath string) {
+	allow := "OPTIONS, LOCK, PUT, MKCOL, PATCH"
+	if fi, err := u.FileSystem.Stat(r.Context(), reqPath); err == nil {
+		if fi.IsDir() {
+			allow = "OPTIONS, LOCK, DELETE, PROPPATCH, COPY, MOVE, UNLOCK, PROPFIND"
+		} else {
+			allow = "OPTIONS, LOCK, GET, HEAD, POST, DELETE, PROPPATCH, COPY, MOVE, UNLOCK, PROPFIND, PUT, PATCH"
+		}
+	}
+
+	w.Header().Set("Allow", allow)
+	w.Header().Set("DAV", "1, 2, sabredav-partialupdate")
+	w.Header().Set("MS-Author-Via", "DAV")
+	w.Header().Set("Accept-Patch", partialUpdateContentType)
+	w.WriteHeader(http.StatusOK)
+}
+
+func (u *handlerUser) handlePartialUpdate(w http.ResponseWriter, r *http.Request, reqPath string) {
+	contentRange := r.Header.Get("Content-Range")
+	isContentRangePut := r.Method == "PUT" && contentRange != ""
+
+	var (
+		updateRange updateRange
+		err         error
+	)
+	if isContentRangePut {
+		updateRange, err = parseContentRange(contentRange)
+	} else {
+		if err := checkPartialUpdateContentType(r.Header.Get("Content-Type")); err != nil {
+			http.Error(w, err.Error(), http.StatusUnsupportedMediaType)
+			return
+		}
+		updateRange, err = parseUpdateRange(r.Header.Get("X-Update-Range"))
+	}
+	if err != nil {
+		writePartialUpdateError(w, err, http.StatusBadRequest)
+		return
+	}
+	if r.Method == "PATCH" && r.ContentLength < 0 {
+		http.Error(w, "missing content length", http.StatusLengthRequired)
+		return
+	}
+
+	release, status, err := u.confirmPartialUpdateLocks(r, reqPath)
+	if err != nil {
+		http.Error(w, err.Error(), status)
+		return
+	}
+	defer release()
+
+	ctx := r.Context()
+	fi, statErr := u.FileSystem.Stat(ctx, reqPath)
+	exists := statErr == nil
+	if statErr != nil && !os.IsNotExist(statErr) {
+		http.Error(w, statErr.Error(), http.StatusMethodNotAllowed)
+		return
+	}
+	if exists && fi.IsDir() {
+		http.Error(w, "cannot update a collection", http.StatusMethodNotAllowed)
+		return
+	}
+
+	etag, status, err := u.checkPartialUpdatePreconditions(r, exists, fi)
+	if err != nil {
+		if etag != "" {
+			w.Header().Set("ETag", etag)
+		}
+		http.Error(w, err.Error(), status)
+		return
+	}
+
+	currentSize := int64(0)
+	if exists {
+		currentSize = fi.Size()
+	}
+	if updateRange.append {
+		updateRange.offset = currentSize
+	} else if updateRange.offset < 0 {
+		updateRange.offset += currentSize
+		if updateRange.offset < 0 {
+			updateRange.offset = 0
+		}
+	}
+
+	if updateRange.hasEnd {
+		expected := updateRange.end - updateRange.offset + 1
+		if expected < 0 {
+			http.Error(w, "invalid byte range", http.StatusRequestedRangeNotSatisfiable)
+			return
+		}
+		if r.ContentLength >= 0 && r.ContentLength != expected {
+			http.Error(w, "content length does not match byte range", http.StatusRequestedRangeNotSatisfiable)
+			return
+		}
+	}
+
+	body := io.Reader(r.Body)
+	var cleanup func()
+	if updateRange.hasEnd {
+		body, cleanup, err = spoolBoundedBody(r.Body, updateRange.end-updateRange.offset+1)
+		if err != nil {
+			writePartialUpdateError(w, err, http.StatusMethodNotAllowed)
+			return
+		}
+		defer cleanup()
+	}
+
+	flag := os.O_RDWR
+	if !exists {
+		flag |= os.O_CREATE
+	}
+	f, err := u.FileSystem.OpenFile(ctx, reqPath, flag, 0666)
+	if err != nil {
+		if os.IsNotExist(err) {
+			http.Error(w, err.Error(), http.StatusConflict)
+			return
+		}
+		http.Error(w, err.Error(), http.StatusNotFound)
+		return
+	}
+	defer func() { _ = f.Close() }()
+
+	if _, err := f.Seek(updateRange.offset, io.SeekStart); err != nil {
+		http.Error(w, err.Error(), http.StatusMethodNotAllowed)
+		return
+	}
+	if _, err := io.Copy(f, body); err != nil {
+		http.Error(w, err.Error(), http.StatusMethodNotAllowed)
+		return
+	}
+
+	if !exists {
+		w.WriteHeader(http.StatusCreated)
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
+func checkPartialUpdateContentType(contentType string) error {
+	if contentType == "" {
+		return errors.New("missing content type")
+	}
+	mediaType, _, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return err
+	}
+	if mediaType != partialUpdateContentType {
+		return fmt.Errorf("unsupported content type %q", mediaType)
+	}
+	return nil
+}
+
+func (u *handlerUser) checkPartialUpdatePreconditions(r *http.Request, exists bool, fi os.FileInfo) (etag string, status int, err error) {
+	ifMatch := r.Header.Get("If-Match")
+	ifNoneMatch := r.Header.Get("If-None-Match")
+	if ifMatch == "" && ifNoneMatch == "" {
+		return "", 0, nil
+	}
+
+	if ifMatch != "" && !exists {
+		return "", http.StatusPreconditionFailed, errors.New("resource does not exist")
+	}
+
+	if exists {
+		etag, err = findPartialETag(r.Context(), fi)
+		if err != nil {
+			return "", http.StatusInternalServerError, err
+		}
+	}
+
+	if ifMatch != "" && !partialETagHeaderMatches(ifMatch, etag, exists) {
+		return etag, http.StatusPreconditionFailed, errors.New("etag does not match")
+	}
+
+	if ifNoneMatch != "" && exists && partialETagHeaderMatches(ifNoneMatch, etag, true) {
+		return etag, http.StatusPreconditionFailed, errors.New("etag matches")
+	}
+
+	return etag, 0, nil
+}
+
+func findPartialETag(ctx context.Context, fi os.FileInfo) (string, error) {
+	if etager, ok := fi.(webdav.ETager); ok {
+		etag, err := etager.ETag(ctx)
+		if !errors.Is(err, webdav.ErrNotImplemented) {
+			return etag, err
+		}
+	}
+	return fmt.Sprintf(`"%x%x"`, fi.ModTime().UnixNano(), fi.Size()), nil
+}
+
+func partialETagHeaderMatches(header, etag string, exists bool) bool {
+	for _, item := range strings.Split(header, ",") {
+		item = strings.TrimSpace(item)
+		if item == "*" {
+			return exists
+		}
+		if item == etag || strings.ReplaceAll(item, `\"`, `"`) == etag {
+			return true
+		}
+	}
+	return false
+}
+
+func parseUpdateRange(header string) (updateRange, error) {
+	if header == "" {
+		return updateRange{}, errors.New("missing X-Update-Range header")
+	}
+	if header == "append" {
+		return updateRange{append: true}, nil
+	}
+	if !strings.HasPrefix(header, "bytes=") {
+		return updateRange{}, errors.New("invalid X-Update-Range header")
+	}
+	return parseByteRange(strings.TrimPrefix(header, "bytes="), true)
+}
+
+func parseContentRange(header string) (updateRange, error) {
+	if !strings.HasPrefix(header, "bytes ") {
+		return updateRange{}, errors.New("invalid Content-Range header")
+	}
+	spec, _, ok := strings.Cut(strings.TrimPrefix(header, "bytes "), "/")
+	if !ok {
+		return updateRange{}, errors.New("invalid Content-Range header")
+	}
+	return parseByteRange(spec, false)
+}
+
+func parseByteRange(spec string, allowNegativeStart bool) (updateRange, error) {
+	if strings.HasPrefix(spec, "-") {
+		if !allowNegativeStart {
+			return updateRange{}, errors.New("invalid byte range start")
+		}
+		start, err := strconv.ParseInt(strings.TrimPrefix(spec, "-"), 10, 64)
+		if err != nil || start < 0 {
+			return updateRange{}, errors.New("invalid byte range start")
+		}
+		if start == 0 {
+			return updateRange{append: true}, nil
+		}
+		return updateRange{offset: -start}, nil
+	}
+
+	startText, endText, ok := strings.Cut(spec, "-")
+	if !ok || startText == "" {
+		return updateRange{}, errors.New("invalid byte range")
+	}
+
+	start, err := strconv.ParseInt(startText, 10, 64)
+	if err != nil {
+		return updateRange{}, errors.New("invalid byte range start")
+	}
+	if start < 0 && !allowNegativeStart {
+		return updateRange{}, errors.New("invalid byte range start")
+	}
+
+	r := updateRange{offset: start}
+	if endText == "" {
+		return r, nil
+	}
+	if start < 0 {
+		return updateRange{}, errors.New("negative byte range cannot include an end")
+	}
+
+	end, err := strconv.ParseInt(endText, 10, 64)
+	if err != nil {
+		return updateRange{}, errors.New("invalid byte range end")
+	}
+	if end < start {
+		return updateRange{}, newPartialUpdateError(http.StatusRequestedRangeNotSatisfiable, "invalid byte range")
+	}
+	r.end = end
+	r.hasEnd = true
+	return r, nil
+}
+
+func spoolBoundedBody(body io.Reader, expected int64) (io.Reader, func(), error) {
+	tmp, err := os.CreateTemp("", "webdav-partial-update-*")
+	if err != nil {
+		return nil, nil, err
+	}
+	cleanup := func() {
+		name := tmp.Name()
+		_ = tmp.Close()
+		_ = os.Remove(name)
+	}
+	cleanupOnError := true
+	defer func() {
+		if cleanupOnError {
+			cleanup()
+		}
+	}()
+
+	n, err := io.Copy(tmp, io.LimitReader(body, expected+1))
+	if err != nil {
+		return nil, nil, err
+	}
+	if n != expected {
+		return nil, nil, newPartialUpdateError(http.StatusRequestedRangeNotSatisfiable, "body length does not match byte range")
+	}
+
+	if _, err := tmp.Seek(0, io.SeekStart); err != nil {
+		return nil, nil, err
+	}
+	cleanupOnError = false
+	return tmp, cleanup, nil
+}
+
+// confirmPartialUpdateLocks mirrors the unexported confirmLocks helper from
+// golang.org/x/net/webdav so that partial updates honor WebDAV locks the same
+// way regular PUT requests do. Keep it in sync if the upstream behavior changes.
+func (u *handlerUser) confirmPartialUpdateLocks(r *http.Request, src string) (release func(), status int, err error) {
+	hdr := r.Header.Get("If")
+	if hdr == "" {
+		now := time.Now()
+		token, err := u.LockSystem.Create(now, webdav.LockDetails{
+			Root:      src,
+			Duration:  -1,
+			ZeroDepth: true,
+		})
+		if err != nil {
+			if errors.Is(err, webdav.ErrLocked) {
+				return nil, webdav.StatusLocked, err
+			}
+			return nil, http.StatusInternalServerError, err
+		}
+		return func() {
+			_ = u.LockSystem.Unlock(now, token)
+		}, 0, nil
+	}
+
+	ifLists, ok := parsePartialIfHeader(hdr)
+	if !ok {
+		return nil, http.StatusBadRequest, errors.New("webdav: invalid If header")
+	}
+	for _, l := range ifLists {
+		lsrc := l.resourceTag
+		if lsrc == "" {
+			lsrc = src
+		} else {
+			parsedURL, err := url.Parse(lsrc)
+			if err != nil {
+				continue
+			}
+			if parsedURL.Host != r.Host {
+				continue
+			}
+			lsrc, err = stripPartialPrefix(parsedURL.Path, u.Prefix)
+			if err != nil {
+				return nil, http.StatusNotFound, err
+			}
+			if lsrc == "" {
+				lsrc = src
+			}
+		}
+		release, err = u.LockSystem.Confirm(time.Now(), lsrc, "", l.conditions...)
+		if errors.Is(err, webdav.ErrConfirmationFailed) {
+			continue
+		}
+		if err != nil {
+			return nil, http.StatusInternalServerError, err
+		}
+		return release, 0, nil
+	}
+	return nil, http.StatusPreconditionFailed, webdav.ErrLocked
+}
+
+type partialIfList struct {
+	resourceTag string
+	conditions  []webdav.Condition
+}
+
+// parsePartialIfHeader, parsePartialIfConditions and cutPartialIfToken
+// reimplement the unexported If-header parser from golang.org/x/net/webdav,
+// which is not accessible from outside that package. Keep them in sync with the
+// upstream parseIfHeader if it changes.
+func parsePartialIfHeader(header string) ([]partialIfList, bool) {
+	s := strings.TrimSpace(header)
+	tagged := strings.HasPrefix(s, "<")
+	var lists []partialIfList
+	for s != "" {
+		resourceTag := ""
+		if strings.HasPrefix(s, "<") {
+			if !tagged {
+				return nil, false
+			}
+			var ok bool
+			resourceTag, s, ok = cutPartialIfToken(s, '<', '>')
+			if !ok {
+				return nil, false
+			}
+			s = strings.TrimSpace(s)
+			if !strings.HasPrefix(s, "(") {
+				return nil, false
+			}
+		}
+		for strings.HasPrefix(s, "(") {
+			body, rest, ok := cutPartialIfToken(s, '(', ')')
+			if !ok {
+				return nil, false
+			}
+			conditions, ok := parsePartialIfConditions(body)
+			if !ok {
+				return nil, false
+			}
+			lists = append(lists, partialIfList{resourceTag: resourceTag, conditions: conditions})
+			s = strings.TrimSpace(rest)
+		}
+		if s != "" && !strings.HasPrefix(s, "<") {
+			return nil, false
+		}
+	}
+	return lists, len(lists) > 0
+}
+
+func parsePartialIfConditions(s string) ([]webdav.Condition, bool) {
+	var conditions []webdav.Condition
+	for {
+		s = strings.TrimSpace(s)
+		if s == "" {
+			return conditions, len(conditions) > 0
+		}
+		not := false
+		if strings.HasPrefix(s, "Not ") || strings.HasPrefix(s, "Not\t") {
+			not = true
+			s = strings.TrimSpace(s[3:])
+		}
+		if s == "" {
+			return nil, false
+		}
+		var token string
+		switch s[0] {
+		case '<':
+			var ok bool
+			token, s, ok = cutPartialIfToken(s, '<', '>')
+			if !ok {
+				return nil, false
+			}
+			conditions = append(conditions, webdav.Condition{Not: not, Token: token})
+		case '[':
+			var ok bool
+			token, s, ok = cutPartialIfToken(s, '[', ']')
+			if !ok {
+				return nil, false
+			}
+			conditions = append(conditions, webdav.Condition{Not: not, ETag: token})
+		default:
+			i := strings.IndexAny(s, " \t")
+			if i < 0 {
+				token, s = s, ""
+			} else {
+				token, s = s[:i], s[i:]
+			}
+			if token == "" || strings.ContainsAny(token, "()<>[]") {
+				return nil, false
+			}
+			conditions = append(conditions, webdav.Condition{Not: not, Token: token})
+		}
+	}
+}
+
+func cutPartialIfToken(s string, open, close byte) (string, string, bool) {
+	if s == "" || s[0] != open {
+		return "", "", false
+	}
+	token, rest, ok := strings.Cut(s[1:], string(close))
+	return token, rest, ok
+}
+
+func stripPartialPrefix(p, prefix string) (string, error) {
+	if prefix == "" {
+		return p, nil
+	}
+	if stripped := strings.TrimPrefix(p, prefix); len(stripped) < len(p) {
+		return stripped, nil
+	}
+	return "", errors.New("webdav: prefix mismatch")
+}

lib/permissions.go

@@ -152,7 +152,7 @@ func (p Permissions) Allowed(r *request, fileExists func(string) bool) bool {
 		return p.Create
 	case "PROPPATCH":
 		return p.Update
-	case "PUT":
+	case "PUT", "PATCH":
 		if fileExists(r.path) {
 			return p.Update
 		} else {