fix: Makes SP after status code mandatory

README.md

@@ -407,6 +407,15 @@ this flag, control characters (except for NULL, CR & LF) will be accepted in hea
 This does not create any known security issue, but does allow content considered 'invalid' by
 [RFC 9110](https://www.rfc-editor.org/rfc/rfc9110#name-field-values) and so should be avoided by default.
 
+### `void llhttp_set_lenient_optional_sp_after_status(llhttp_t* parser, int enabled)`
+
+Enables/disables lenient handling of spaces after status code
+
+As per [RFC 9112](https://www.rfc-editor.org/info/rfc9112/#section-4-8):
+> A server MUST send the space that separates the status-code from the reason-phrase even when the reason-phrase is absent (i.e., the status-line would end with the space).
+
+This flag allows status code with no trailing space.
+
 ## Build Instructions
 
 Make sure you have [Node.js](https://nodejs.org/), npm and npx installed. Then under project directory run:

src/llhttp/constants.ts

@@ -80,6 +80,7 @@ export const LENIENT_FLAGS = {
   OPTIONAL_CR_BEFORE_LF: 1 << 8,
   SPACES_AFTER_CHUNK_SIZE: 1 << 9,
   HEADER_VALUE_RELAXED: 1 << 10,
+  OPTIONAL_SP_AFTER_STATUS: 1 << 11,
 } as const;
 
 export const STATUSES = {

src/llhttp/http.ts

@@ -39,7 +39,7 @@ const NODES = [
   'res_status_code_digit_1',
   'res_status_code_digit_2',
   'res_status_code_digit_3',
-  'res_status_code_otherwise',
+  'res_status_trailing_space',
   'res_status_start',
   'res_status',
   'res_line_almost_done',
@@ -385,25 +385,23 @@ export class HTTP {
     n('res_status_code_digit_3')
       .select(NUM_MAP, this.mulAdd('status_code', {
         overflow: p.error(ERROR.INVALID_STATUS, 'Invalid status code'),
-        success: 'res_status_code_otherwise',
+        success: 'res_status_trailing_space',
       }))
       .otherwise(p.error(ERROR.INVALID_STATUS, 'Invalid status code'));
 
     const onStatusComplete = this.invokePausable(
       'on_status_complete', ERROR.CB_STATUS_COMPLETE, n('headers_start'),
     );
 
-    n('res_status_code_otherwise')
+    n('res_status_trailing_space')
       .match(' ', n('res_status_start'))
-      .match('\r', n('res_line_almost_done'))
-      .match(
-        '\n',
-        checkIfAllowLFWithoutCR(
-          onStatusComplete,
-          p.error(ERROR.INVALID_STATUS, 'Invalid response status'),
-        ),
-      )
-      .otherwise(p.error(ERROR.INVALID_STATUS, 'Invalid response status'));
+      .otherwise(
+        this.testLenientFlags(
+          LENIENT_FLAGS.OPTIONAL_SP_AFTER_STATUS,
+          { 1: n('res_line_almost_done') },
+          p.error(ERROR.INVALID_STATUS, 'Invalid response status')
+        )
+      );
 
     n('res_status_start')
       .otherwise(span.status.start(n('res_status')));

src/native/api.c

@@ -324,6 +324,14 @@ void llhttp_set_lenient_header_value_relaxed(llhttp_t* parser, int enabled) {
   }
 }
 
+void llhttp_set_lenient_optional_sp_after_status(llhttp_t* parser, int enabled) {
+  if (enabled) {
+    parser->lenient_flags |= LENIENT_OPTIONAL_SP_AFTER_STATUS;
+  } else {
+    parser->lenient_flags &= ~LENIENT_OPTIONAL_SP_AFTER_STATUS;
+  }
+}
+
 /* Callbacks */
 
 

src/native/api.h

@@ -370,6 +370,18 @@ void llhttp_set_lenient_spaces_after_chunk_size(llhttp_t* parser, int enabled);
 LLHTTP_EXPORT
 void llhttp_set_lenient_header_value_relaxed(llhttp_t* parser, int enabled);
 
+/* Enables/disables lenient handling of spaces after status code
+ *
+ * As per RFC 9112:
+ * A server MUST send the space that separates the status-code from the 
+ * reason-phrase even when the reason-phrase is absent 
+ * (i.e., the status-line would end with the space).
+ *
+ * This flag allows status code with no trailing space.
+ */
+LLHTTP_EXPORT
+void llhttp_set_lenient_optional_sp_after_status(llhttp_t* parser, int enabled);
+
 #ifdef __cplusplus
 }  /* extern "C" */
 #endif

test/fixtures/extra.c

@@ -201,6 +201,16 @@ void llhttp__test_init_response_lenient_header_value_relaxed(llparse_t* s) {
   s->lenient_flags |= LENIENT_HEADER_VALUE_RELAXED;
 }
 
+void llhttp__test_init_request_lenient_optional_sp_after_status(llparse_t* s) {
+  llhttp__test_init_request(s);
+  s->lenient_flags |= LENIENT_OPTIONAL_SP_AFTER_STATUS;
+}
+
+void llhttp__test_init_response_lenient_optional_sp_after_status(llparse_t* s) {
+  llhttp__test_init_response(s);
+  s->lenient_flags |= LENIENT_OPTIONAL_SP_AFTER_STATUS;
+}
+
 
 void llhttp__test_finish(llparse_t* s) {
   llparse__print(NULL, NULL, "finish=%d", s->finish);

test/response/invalid.md

@@ -67,7 +67,6 @@ off=5 len=3 span[version]="1.0"
 off=8 version complete
 off=8 error code=9 reason="Expected space after version"
 ```
--->
 
 ### Tab after HTTP version
 
@@ -266,6 +265,24 @@ off=18 status complete
 off=20 headers complete status=200 v=1/1 flags=0 content_length=0
 ```
 
+### No space after status code (no reason)
+
+<!-- meta={"type": "response"} -->
+```http
+HTTP/1.1 301
+
+
+```
+
+```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=12 error code=13 reason="Invalid response status"
+```
+
 ### One-digit status code
 
 <!-- meta={"type": "response"} -->

test/response/sample.md

@@ -288,25 +288,6 @@ off=24 status complete
 off=26 headers complete status=404 v=1/1 flags=0 content_length=0
 ```
 
-## No reason phrase
-
-<!-- meta={"type": "response"} -->
-```http
-HTTP/1.1 301
-
-
-```
-
-```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=14 status complete
-off=16 headers complete status=301 v=1/1 flags=0 content_length=0
-```
-
 ## Empty reason phrase after space
 
 <!-- meta={"type": "response"} -->