"net/http"
"net/url"
"os"
+ "regexp"
+ "strconv"
"strings"
- "time"
"git.curoverse.com/arvados.git/sdk/go/arvadosclient"
"git.curoverse.com/arvados.git/sdk/go/auth"
type handler struct{}
var (
- clientPool = arvadosclient.MakeClientPool()
- trustAllContent = false
- anonymousTokens []string
+ clientPool = arvadosclient.MakeClientPool()
+ trustAllContent = false
+ attachmentOnlyHost = ""
)
func init() {
+ flag.StringVar(&attachmentOnlyHost, "attachment-only-host", "",
+ "Accept credentials, and add \"Content-Disposition: attachment\" response headers, for requests at this hostname:port. Prohibiting inline display makes it possible to serve untrusted and non-public content from a single origin, i.e., without wildcard DNS or SSL.")
flag.BoolVar(&trustAllContent, "trust-all-content", false,
"Serve non-public content from a single origin. Dangerous: read docs before using!")
}
// return a UUID or PDH if s begins with a UUID or URL-encoded PDH;
// otherwise return "".
-func parseCollectionIdFromDNSName(s string) string {
+func parseCollectionIDFromDNSName(s string) string {
// Strip domain.
if i := strings.IndexRune(s, '.'); i >= 0 {
s = s[:i]
}
- // Names like {uuid}--dl.example.com serve the same purpose as
- // {uuid}.dl.example.com but can reduce cost/effort of using
- // [additional] wildcard certificates.
+ // Names like {uuid}--collections.example.com serve the same
+ // purpose as {uuid}.collections.example.com but can reduce
+ // cost/effort of using [additional] wildcard certificates.
if i := strings.Index(s, "--"); i >= 0 {
s = s[:i]
}
// return a UUID or PDH if s is a UUID or a PDH (even if it is a PDH
// with "+" replaced by " " or "-"); otherwise return "".
-func parseCollectionIdFromURL(s string) string {
+func parseCollectionIDFromURL(s string) string {
if arvadosclient.UUIDMatch(s) {
return s
}
return
}
+ if r.Header.Get("Origin") != "" {
+ // Allow simple cross-origin requests without user
+ // credentials ("user credentials" as defined by CORS,
+ // i.e., cookies, HTTP authentication, and client-side
+ // SSL certificates. See
+ // http://www.w3.org/TR/cors/#user-credentials).
+ w.Header().Set("Access-Control-Allow-Origin", "*")
+ }
+
arv := clientPool.Get()
if arv == nil {
statusCode, statusText = http.StatusInternalServerError, "Pool failed: "+clientPool.Err().Error()
pathParts := strings.Split(r.URL.Path[1:], "/")
- var targetId string
+ var targetID string
var targetPath []string
var tokens []string
var reqTokens []string
var pathToken bool
+ var attachment bool
credentialsOK := trustAllContent
- if targetId = parseCollectionIdFromDNSName(r.Host); targetId != "" {
- // http://ID.dl.example/PATH...
+ if r.Host != "" && r.Host == attachmentOnlyHost {
+ credentialsOK = true
+ attachment = true
+ } else if r.FormValue("disposition") == "attachment" {
+ attachment = true
+ }
+
+ if targetID = parseCollectionIDFromDNSName(r.Host); targetID != "" {
+ // http://ID.collections.example/PATH...
credentialsOK = true
targetPath = pathParts
} else if len(pathParts) >= 2 && strings.HasPrefix(pathParts[0], "c=") {
// /c=ID/PATH...
- targetId = parseCollectionIdFromURL(pathParts[0][2:])
+ targetID = parseCollectionIDFromURL(pathParts[0][2:])
targetPath = pathParts[1:]
} else if len(pathParts) >= 3 && pathParts[0] == "collections" {
if len(pathParts) >= 5 && pathParts[1] == "download" {
// /collections/download/ID/TOKEN/PATH...
- targetId = pathParts[2]
+ targetID = pathParts[2]
tokens = []string{pathParts[3]}
targetPath = pathParts[4:]
pathToken = true
} else {
// /collections/ID/PATH...
- targetId = pathParts[1]
+ targetID = pathParts[1]
tokens = anonymousTokens
targetPath = pathParts[2:]
}
statusCode = http.StatusNotFound
return
}
- if t := r.FormValue("api_token"); t != "" {
+
+ formToken := r.FormValue("api_token")
+ if formToken != "" && r.Header.Get("Origin") != "" && attachment && r.URL.Query().Get("api_token") == "" {
+ // The client provided an explicit token in the POST
+ // body. The Origin header indicates this *might* be
+ // an AJAX request, in which case redirect-with-cookie
+ // won't work: we should just serve the content in the
+ // POST response. This is safe because:
+ //
+ // * We're supplying an attachment, not inline
+ // content, so we don't need to convert the POST to
+ // a GET and avoid the "really resubmit form?"
+ // problem.
+ //
+ // * The token isn't embedded in the URL, so we don't
+ // need to worry about bookmarks and copy/paste.
+ tokens = append(tokens, formToken)
+ } else if formToken != "" {
// The client provided an explicit token in the query
// string, or a form in POST body. We must put the
// token in an HttpOnly cookie, and redirect to the
// resulting page.
http.SetCookie(w, &http.Cookie{
- Name: "api_token",
- Value: auth.EncodeTokenCookie([]byte(t)),
+ Name: "arvados_api_token",
+ Value: auth.EncodeTokenCookie([]byte(formToken)),
Path: "/",
- Expires: time.Now().AddDate(10, 0, 0),
HttpOnly: true,
})
- redir := (&url.URL{Host: r.Host, Path: r.URL.Path}).String()
+
+ // Propagate query parameters (except api_token) from
+ // the original request.
+ redirQuery := r.URL.Query()
+ redirQuery.Del("api_token")
+
+ redir := (&url.URL{
+ Host: r.Host,
+ Path: r.URL.Path,
+ RawQuery: redirQuery.Encode(),
+ }).String()
w.Header().Add("Location", redir)
statusCode, statusText = http.StatusSeeOther, redir
if len(targetPath) > 0 && targetPath[0] == "_" {
// If a collection has a directory called "t=foo" or
- // "_", it can be served at //dl.example/_/t=foo/ or
- // //dl.example/_/_/ respectively: //dl.example/t=foo/
- // won't work because t=foo will be interpreted as a
- // token "foo".
+ // "_", it can be served at
+ // //collections.example/_/t=foo/ or
+ // //collections.example/_/_/ respectively:
+ // //collections.example/t=foo/ won't work because
+ // t=foo will be interpreted as a token "foo".
targetPath = targetPath[1:]
}
collection := make(map[string]interface{})
found := false
for _, arv.ApiToken = range tokens {
- err := arv.Get("collections", targetId, nil, &collection)
+ err := arv.Get("collections", targetID, nil, &collection)
if err == nil {
// Success
found = true
// someone trying (anonymously) to download public
// data that has been deleted. Allow a referrer to
// provide this context somehow?
- w.Header().Add("WWW-Authenticate", "Basic realm=\"dl\"")
+ w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"")
statusCode = http.StatusUnauthorized
return
}
}
defer rdr.Close()
- // One or both of these can be -1 if not found:
basenamePos := strings.LastIndex(filename, "/")
+ if basenamePos < 0 {
+ basenamePos = 0
+ }
extPos := strings.LastIndex(filename, ".")
if extPos > basenamePos {
// Now extPos is safely >= 0.
w.Header().Set("Content-Type", t)
}
}
- w.Header().Set("Content-Length", fmt.Sprintf("%d", rdr.Len()))
+ if rdr, ok := rdr.(keepclient.ReadCloserWithLen); ok {
+ w.Header().Set("Content-Length", fmt.Sprintf("%d", rdr.Len()))
+ }
+
+ applyContentDispositionHdr(w, r, filename[basenamePos:], attachment)
+ rangeRdr, statusCode := applyRangeHdr(w, r, rdr)
- w.WriteHeader(http.StatusOK)
- _, err = io.Copy(w, rdr)
+ w.WriteHeader(statusCode)
+ _, err = io.Copy(w, rangeRdr)
if err != nil {
statusCode, statusText = http.StatusBadGateway, err.Error()
}
}
+
+var rangeRe = regexp.MustCompile(`^bytes=0-([0-9]*)$`)
+
+func applyRangeHdr(w http.ResponseWriter, r *http.Request, rdr keepclient.ReadCloserWithLen) (io.Reader, int) {
+ w.Header().Set("Accept-Ranges", "bytes")
+ hdr := r.Header.Get("Range")
+ fields := rangeRe.FindStringSubmatch(hdr)
+ if fields == nil {
+ return rdr, http.StatusOK
+ }
+ rangeEnd, err := strconv.ParseInt(fields[1], 10, 64)
+ if err != nil {
+ // Empty or too big for int64 == send entire content
+ return rdr, http.StatusOK
+ }
+ if uint64(rangeEnd) >= rdr.Len() {
+ return rdr, http.StatusOK
+ }
+ w.Header().Set("Content-Length", fmt.Sprintf("%d", rangeEnd+1))
+ w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", 0, rangeEnd, rdr.Len()))
+ return &io.LimitedReader{R: rdr, N: rangeEnd + 1}, http.StatusPartialContent
+}
+
+func applyContentDispositionHdr(w http.ResponseWriter, r *http.Request, filename string, isAttachment bool) {
+ disposition := "inline"
+ if isAttachment {
+ disposition = "attachment"
+ }
+ if strings.ContainsRune(r.RequestURI, '?') {
+ // Help the UA realize that the filename is just
+ // "filename.txt", not
+ // "filename.txt?disposition=attachment".
+ //
+ // TODO(TC): Follow advice at RFC 6266 appendix D
+ disposition += "; filename=" + strconv.QuoteToASCII(filename)
+ }
+ if disposition != "inline" {
+ w.Header().Set("Content-Disposition", disposition)
+ }
+}