server: adding no-store header (#476)

In order to prevent viewing content, which max-download rate has been reached,
we need to ensure the data is not stored locally in a browser cache.
To achieve this, we set the Cache-Control Setting to "no-store" according to:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control

fixes #470

.github/workflows/build-docker-images.yml

@@ -34,9 +34,11 @@ jobs:
           fi
 
           TAGS="--tag ${DOCKER_IMAGE}:${VERSION}"
+          TAGS_NOROOT="--tag ${DOCKER_IMAGE}:${VERSION}-noroot"
 
           if [ $VERSION = edge -o $VERSION = nightly ]; then
             TAGS="$TAGS --tag ${DOCKER_IMAGE}:latest"
+            TAGS_NOROOT="$TAGS_NOROOT --tag ${DOCKER_IMAGE}:latest-noroot"
           fi
 
           echo ::set-output name=docker_image::${DOCKER_IMAGE}
@@ -46,6 +48,12 @@ jobs:
             --build-arg BUILD_DATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ') \
             --build-arg VCS_REF=${GITHUB_SHA::8} \
             ${TAGS} .
+          echo ::set-output name=buildx_args_noroot::--platform ${DOCKER_PLATFORMS} \
+            --build-arg VERSION=${VERSION} \
+            --build-arg BUILD_DATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ') \
+            --build-arg VCS_REF=${GITHUB_SHA::8} \
+            --build-arg RUNAS=noroot \
+            ${TAGS_NOROOT} .
       -
         name: Set up QEMU
         uses: docker/setup-qemu-action@v1
@@ -64,6 +72,7 @@ jobs:
         name: Docker Buildx (build)
         run: |
           docker buildx build --no-cache --pull --output "type=image,push=false" ${{ steps.prepare.outputs.buildx_args }}
+          docker buildx build --output "type=image,push=false" ${{ steps.prepare.outputs.buildx_args_noroot }}
       -
         name: Docker Login
         if: success() && github.event_name != 'pull_request'
@@ -77,11 +86,13 @@ jobs:
         if: success() && github.event_name != 'pull_request'
         run: |
           docker buildx build --output "type=image,push=true" ${{ steps.prepare.outputs.buildx_args }}
+          docker buildx build --output "type=image,push=true" ${{ steps.prepare.outputs.buildx_args_noroot }}
       -
         name: Docker Check Manifest
         if: always() && github.event_name != 'pull_request'
         run: |
           docker run --rm mplatform/mquery ${{ steps.prepare.outputs.docker_image }}:${{ steps.prepare.outputs.version }}
+          docker run --rm mplatform/mquery ${{ steps.prepare.outputs.docker_image }}:${{ steps.prepare.outputs.version }}-noroot
       -
         name: Clear
         if: always() && github.event_name != 'pull_request'

Dockerfile

@@ -14,12 +14,27 @@ ENV GO111MODULE=on
 # build & install server
 RUN CGO_ENABLED=0 go build -tags netgo -ldflags "-X github.com/dutchcoders/transfer.sh/cmd.Version=$(git describe --tags) -a -s -w -extldflags '-static'" -o /go/bin/transfersh
 
+ARG PUID=5000 \
+    PGID=5000 \
+    RUNAS
+
+RUN mkdir -p /tmp/useradd && \
+    if [ ! -z "$RUNAS" ]; then \
+    echo "${RUNAS}:x:${PUID}:${PGID}::/nonexistent:/sbin/nologin" >> /tmp/useradd/passwd && \
+    echo "${RUNAS}:!:::::::" >> /tmp/useradd/shadow && \
+    echo "${RUNAS}:x:${PGID}:" >> /tmp/useradd/group && \
+    echo "${RUNAS}:!::" >> /tmp/useradd/groupshadow; else touch /tmp/useradd/unused; fi
+
 FROM scratch AS final
 LABEL maintainer="Andrea Spacca <andrea.spacca@gmail.com>"
+ARG RUNAS
 
-COPY --from=build  /go/bin/transfersh /go/bin/transfersh
+COPY --from=build /tmp/useradd/* /etc/
+COPY --from=build --chown=${RUNAS}  /go/bin/transfersh /go/bin/transfersh
 COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
 
+USER ${RUNAS}
+
 ENTRYPOINT ["/go/bin/transfersh", "--listener", ":8080"]
 
 EXPOSE 8080

README.md

@@ -140,12 +140,31 @@ $ go build -o transfersh main.go
 
 ## Docker
 
-For easy deployment, we've created a Docker container.
+For easy deployment, we've created an official Docker container. There are two variants, differing only by which user runs the process.
+
+The default one will run as `root`:
 
 ```bash
 docker run --publish 8080:8080 dutchcoders/transfer.sh:latest --provider local --basedir /tmp/
 ```
 
+The one tagged with the suffix `-noroot` will use `5000` as both UID and GID:
+```bash
+docker run --publish 8080:8080 dutchcoders/transfer.sh:latest-noroot --provider local --basedir /tmp/
+```
+
+### Building the Container
+You can also build the container yourself. This allows you to choose which UID/GID will be used, e.g. when using NFS mounts:
+```bash
+# Build arguments:
+# * RUNAS: If empty, the container will run as root.
+#          Set this to anything to enable UID/GID selection.
+# * PUID:  UID of the process. Needs RUNAS != "". Defaults to 5000.
+# * PGID:  GID of the process. Needs RUNAS != "". Defaults to 5000.
+
+docker build -t transfer.sh-noroot --build-arg RUNAS=doesntmatter --build-arg PUID=1337 --build-arg PGID=1338 .
+```
+
 ## S3 Usage
 
 For the usage with a AWS S3 Bucket, you just need to specify the following options:
@@ -204,6 +223,41 @@ You need to create an OAuth Client id from console.cloud.google.com, download th
 
 ```go run main.go --provider gdrive --basedir /tmp/ --gdrive-client-json-filepath /[credential_dir] --gdrive-local-config-path [directory_to_save_config] ```
 
+## Shell functions
+
+### Bash and zsh (multiple files uploaded as zip archive)
+##### Add this to .bashrc or .zshrc or its equivalent
+```bash
+transfer(){ if [ $# -eq 0 ];then echo "No arguments specified.\nUsage:\n transfer <file|directory>\n ... | transfer <file_name>">&2;return 1;fi;if tty -s;then file="$1";file_name=$(basename "$file");if [ ! -e "$file" ];then echo "$file: No such file or directory">&2;return 1;fi;if [ -d "$file" ];then file_name="$file_name.zip" ,;(cd "$file"&&zip -r -q - .)|curl --progress-bar --upload-file "-" "https://transfer.sh/$file_name"|tee /dev/null,;else cat "$file"|curl --progress-bar --upload-file "-" "https://transfer.sh/$file_name"|tee /dev/null;fi;else file_name=$1;curl --progress-bar --upload-file "-" "https://transfer.sh/$file_name"|tee /dev/null;fi;}
+```
+
+#### Now you can use transfer function
+```
+$ transfer hello.txt
+```
+
+
+### Zsh (with delete url outpu)
+##### Add this to .zshrc or its equivalent
+```bash
+transfer()
+{
+    local file="${1}"
+    local filename="${file##*/}"
+    # show delete link from the response header after upload. the command "sed" is necessary to clean up the output, "gsub()" in "awk" does not work.
+    curl --request PUT --progress-bar --dump-header - --upload-file "${file}" "https://transfer.sh/${filename}" | sed "s/#//g" | awk '/x-url-delete/ { print "Delete command: curl --request DELETE " $2 } END{ print "Download link: " $1 }'
+}
+```
+
+#### Sample ouput
+```bash
+$ transfer image.img
+######################################################################################################################################################################################################################################## 100.0%
+Delete command: curl --request DELETE https://transfer.sh/Ge9cuW/image.img/<some_delete_token>
+Download link: https://transfer.sh/Ge9cuW/image.img
+```
+
+
 ## Contributions
 
 Contributions are welcome.

server/handlers.go

@@ -781,8 +781,7 @@ func (s *Server) zipHandler(w http.ResponseWriter, r *http.Request) {
 	zipfilename := fmt.Sprintf("transfersh-%d.zip", uint16(time.Now().UnixNano()))
 
 	w.Header().Set("Content-Type", "application/zip")
-	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", zipfilename))
-	w.Header().Set("Connection", "close")
+	commonHeader(w, zipfilename)
 
 	zw := zip.NewWriter(w)
 
@@ -848,8 +847,7 @@ func (s *Server) tarGzHandler(w http.ResponseWriter, r *http.Request) {
 	tarfilename := fmt.Sprintf("transfersh-%d.tar.gz", uint16(time.Now().UnixNano()))
 
 	w.Header().Set("Content-Type", "application/x-gzip")
-	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", tarfilename))
-	w.Header().Set("Connection", "close")
+	commonHeader(w, tarfilename)
 
 	gw := gzip.NewWriter(w)
 	defer CloseCheck(gw.Close)
@@ -910,8 +908,7 @@ func (s *Server) tarHandler(w http.ResponseWriter, r *http.Request) {
 	tarfilename := fmt.Sprintf("transfersh-%d.tar", uint16(time.Now().UnixNano()))
 
 	w.Header().Set("Content-Type", "application/x-tar")
-	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", tarfilename))
-	w.Header().Set("Connection", "close")
+	commonHeader(w, tarfilename)
 
 	zw := tar.NewWriter(w)
 	defer CloseCheck(zw.Close)
@@ -1037,6 +1034,7 @@ func (s *Server) getHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Length", strconv.FormatUint(contentLength, 10))
 	w.Header().Set("Content-Disposition", fmt.Sprintf("%s; filename=\"%s\"", disposition, filename))
 	w.Header().Set("Connection", "keep-alive")
+	w.Header().Set("Cache-Control", "no-store")
 	w.Header().Set("X-Remaining-Downloads", remainingDownloads)
 	w.Header().Set("X-Remaining-Days", remainingDays)
 
@@ -1072,6 +1070,12 @@ func (s *Server) getHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func commonHeader(w http.ResponseWriter, filename string) {
+	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", filename))
+	w.Header().Set("Connection", "close")
+	w.Header().Set("Cache-Control", "no-store")
+}
+
 // RedirectHandler handles redirect
 func (s *Server) RedirectHandler(h http.Handler) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {

server/server.go

@@ -25,39 +25,34 @@ THE SOFTWARE.
 package server
 
 import (
+	"context"
 	crypto_rand "crypto/rand"
+	"crypto/tls"
 	"encoding/binary"
 	"errors"
-	gorillaHandlers "github.com/gorilla/handlers"
 	"log"
 	"math/rand"
 	"mime"
 	"net/http"
+	_ "net/http/pprof"
 	"net/url"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"strings"
 	"sync"
 	"syscall"
 	"time"
 
-	context "golang.org/x/net/context"
-
 	"github.com/PuerkitoBio/ghost/handlers"
 	"github.com/VojtechVitek/ratelimit"
 	"github.com/VojtechVitek/ratelimit/memory"
+	gorillaHandlers "github.com/gorilla/handlers"
 	"github.com/gorilla/mux"
-
-	// import pprof
-	_ "net/http/pprof"
-
-	"crypto/tls"
+	"golang.org/x/crypto/acme/autocert"
 
 	web "github.com/dutchcoders/transfer.sh-web"
 	assetfs "github.com/elazarl/go-bindata-assetfs"
-
-	autocert "golang.org/x/crypto/acme/autocert"
-	"path/filepath"
 )
 
 // parse request with maximum memory of _24Kilobits