Fix serving boxed blob with range request

- Fix error handling
- Calculate size of unboxed blob

1 files changed, 8 insertions, 1 deletions

diff --git a/lib/serve.js b/lib/serve.js
index a06f566..a9a3691 100644
--- a/lib/serve.js
+++ b/lib/serve.js
@@ -2101,6 +2101,13 @@ Serve.prototype.blob = function (id, path) {
       if (/^invalid/.test(err.message)) return self.respond(400, err.message)
       else return self.respond(500, err.message || err)
     }
+    if (key) {
+      // Transform size of boxed blob to size of cleartext.
+      // Assume that the blob contains box-stream packets that are all full 4096-byte packets except maybe the last one, plus one goodbye packet
+      // boxedlen = origlen + ceil(origlen / 4096)*34 + 34
+      const numBoxHeaders = Math.ceil((size - 34) / 4130) + 1
+      size -= numBoxHeaders * 34
+    }
     self.res.setHeader('Accept-Ranges', 'bytes')
     var range = self.req.headers.range
     if (range) {
@@ -2120,7 +2127,7 @@ Serve.prototype.blob = function (id, path) {
         start = Number(start)
         last = Number(last)
       }
-      if (start > size || last >= size) return res.writeHead(416, 'Range not satisfiable')
+      if (start > size || last >= size) return self.respond(416, 'Range not satisfiable')
       var end = last + 1
       var length = end - start
       var wroteHeaders = false