fix: Do not allow empty transfer-encoding. (#874)

Signed-off-by: Paolo Insogna <paolo@cowtech.it>

Author: ShogunPanda

src/llhttp/http.ts

@@ -685,16 +685,19 @@ export class HTTP {
 
     const emptyContentLengthError = p.error(
       ERROR.INVALID_CONTENT_LENGTH, 'Empty Content-Length');
-    const checkContentLengthEmptiness = this.load('header_state', {
+    const emptyTransferEncodingError = p.error(
+      ERROR.INVALID_TRANSFER_ENCODING, 'Empty Transfer-Encoding');
+    const checkEmptyHeaderValue = this.load('header_state', {
       [HEADER_STATE.CONTENT_LENGTH]: emptyContentLengthError,
+      [HEADER_STATE.TRANSFER_ENCODING]: emptyTransferEncodingError,
     }, this.setHeaderFlags(
       this.emptySpan(span.headerValue, onHeaderValueComplete)));
 
     n('header_value_discard_lws')
       .match([ ' ', '\t' ], this.testLenientFlags(LENIENT_FLAGS.HEADERS, {
         1: n('header_value_discard_ws'),
       }, p.error(ERROR.INVALID_HEADER_TOKEN, 'Invalid header value char')))
-      .otherwise(checkContentLengthEmptiness);
+      .otherwise(checkEmptyHeaderValue);
 
     // Multiple `Transfer-Encoding` headers should be treated as one, but with
     // values separate by a comma.

test/request/transfer-encoding.md

@@ -1,6 +1,32 @@
 Transfer-Encoding header
 ========================
 
+## Empty `Transfer-Encoding` with `Content-Length`
+
+<!-- meta={"type": "request"} -->
+```http
+POST /first HTTP/1.1
+Transfer-Encoding:
+Content-Length: 5
+
+hello
+```
+
+```log
+off=0 message begin
+off=0 len=4 span[method]="POST"
+off=4 method complete
+off=5 len=6 span[url]="/first"
+off=12 url complete
+off=12 len=4 span[protocol]="HTTP"
+off=16 protocol complete
+off=17 len=3 span[version]="1.1"
+off=20 version complete
+off=22 len=17 span[header_field]="Transfer-Encoding"
+off=40 header_field complete
+off=42 error code=15 reason="Empty Transfer-Encoding"
+```
+
 ## `chunked`
 
 ### Parsing and setting flag

test/response/transfer-encoding.md

@@ -1,6 +1,30 @@
 Transfer-Encoding header
 ========================
 
+## Empty `Transfer-Encoding` with `Content-Length`
+
+<!-- meta={"type": "response"} -->
+```http
+HTTP/1.1 200 OK
+Transfer-Encoding:
+Content-Length: 5
+
+hello
+```
+
+```log
+off=0 message begin
+off=0 len=4 span[protocol]="HTTP"
+off=4 protocol complete
+off=5 len=3 span[version]="1.1"
+off=8 version complete
+off=13 len=2 span[status]="OK"
+off=17 status complete
+off=17 len=17 span[header_field]="Transfer-Encoding"
+off=35 header_field complete
+off=37 error code=15 reason="Empty Transfer-Encoding"
+```
+
 ## Trailing space on chunked body
 
 <!-- meta={"type": "response"} -->
@@ -427,4 +451,3 @@ off=66 len=1 span[body]=lf
 off=67 len=1 span[body]=cr
 off=68 len=1 span[body]=lf
 ```
-