17106: Fix key unescape: don't convert + to space.

[arvados.git] / services / keep-web / s3.go

diff --git a/services/keep-web/s3.go b/services/keep-web/s3.go
index 0170146c093357a92e823c464a8e3c2684869686..4ee69f277d7e621d19bf69a1dc8f0cbdf82532ad 100644 (file)
--- a/services/keep-web/s3.go
+++ b/services/keep-web/s3.go
@@ -16,6 +16,7 @@ import (
        "net/url"
        "os"
        "path/filepath"
+       "regexp"
        "sort"
        "strconv"
        "strings"
@@ -111,6 +112,21 @@ func s3signature(secretKey, scope, signedHeaders, stringToSign string) (string,
        return hashdigest(hmac.New(sha256.New, key), stringToSign), nil
 }
 
+var v2tokenUnderscore = regexp.MustCompile(`^v2_[a-z0-9]{5}-gj3su-[a-z0-9]{15}_`)
+
+func unescapeKey(key string) string {
+       if v2tokenUnderscore.MatchString(key) {
+               // Entire Arvados token, with "/" replaced by "_" to
+               // avoid colliding with the Authorization header
+               // format.
+               return strings.Replace(key, "_", "/", -1)
+       } else if s, err := url.PathUnescape(key); err == nil {
+               return s
+       } else {
+               return key
+       }
+}
+
 // checks3signature verifies the given S3 V4 signature and returns the
 // Arvados token that corresponds to the given accessKey. An error is
 // returned if accessKey is not a valid token UUID or the signature
@@ -152,14 +168,7 @@ func (h *handler) checks3signature(r *http.Request) (string, error) {
        } else {
                // Access key and secret key are both an entire
                // Arvados token or OIDC access token.
-               mungedKey := key
-               if strings.HasPrefix(key, "v2_") {
-                       // Entire Arvados token, with "/" replaced by
-                       // "_" to avoid colliding with the
-                       // Authorization header format.
-                       mungedKey = strings.Replace(key, "_", "/", -1)
-               }
-               ctx := arvados.ContextWithAuthorization(r.Context(), "Bearer "+mungedKey)
+               ctx := arvados.ContextWithAuthorization(r.Context(), "Bearer "+unescapeKey(key))
                err = client.RequestAndDecodeContext(ctx, &aca, "GET", "arvados/v1/api_client_authorizations/current", nil, nil)
                secret = key
        }
@@ -190,7 +199,7 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
                        http.Error(w, "malformed Authorization header", http.StatusUnauthorized)
                        return true
                }
-               token = split[0]
+               token = unescapeKey(split[0])
        } else if strings.HasPrefix(auth, s3SignAlgorithm+" ") {
                t, err := h.checks3signature(r)
                if err != nil {