fix: don’t ignore empty request headers (#1182)

AlliBalliBaba · web-flow · commit b4748ee11038 · 2024-11-21T12:58:01.000+01:00
* Fixes empty request headers.

* Formatting
diff --git a/caddy/caddy_test.go b/caddy/caddy_test.go
@@ -607,6 +607,7 @@ func TestAllDefinedServerVars(t *testing.T) {
 			"Content-Length: 14", // maliciously set to 14
 			"Special-Chars: <%00>",
 			"Host: Malicous Host",
+			"X-Empty-Header:",
 		},
 		bytes.NewBufferString("foo=bar"),
 		http.StatusOK,
diff --git a/frankenphp.c b/frankenphp.c
@@ -707,9 +707,12 @@ void frankenphp_register_variables_from_request_info(
  * see: php_variables.c -> php_register_variable_ex (#1106) */
 void frankenphp_register_variable_safe(char *key, char *val, size_t val_len,
                                        zval *track_vars_array) {
-  if (val == NULL || key == NULL) {
+  if (key == NULL) {
     return;
   }
+  if (val == NULL) {
+    val = "";
+  }
   size_t new_val_len = val_len;
   if (!should_filter_var ||
       sapi_module.input_filter(PARSE_SERVER, key, &val, new_val_len,
diff --git a/frankenphp_test.go b/frankenphp_test.go
@@ -952,13 +952,10 @@ func FuzzRequest(f *testing.F) {
 			assert.Contains(t, string(body), fmt.Sprintf("[PATH_INFO] => /%s", fuzzedString))
 			assert.Contains(t, string(body), fmt.Sprintf("[PATH_TRANSLATED] => %s", filepath.Join(absPath, fuzzedString)))
 
-			// The header should only be present if the fuzzed string is not empty
-			if len(fuzzedString) > 0 {
-				assert.Contains(t, string(body), fmt.Sprintf("[CONTENT_TYPE] => %s", fuzzedString))
-				assert.Contains(t, string(body), fmt.Sprintf("[HTTP_FUZZED] => %s", fuzzedString))
-			} else {
-				assert.NotContains(t, string(body), "[HTTP_FUZZED]")
-			}
+			// Headers should always be present even if empty
+			assert.Contains(t, string(body), fmt.Sprintf("[CONTENT_TYPE] => %s", fuzzedString))
+			assert.Contains(t, string(body), fmt.Sprintf("[HTTP_FUZZED] => %s", fuzzedString))
+
 		}, &testOptions{workerScript: "request-headers.php"})
 	})
 }
diff --git a/testdata/server-all-vars-ordered.php b/testdata/server-all-vars-ordered.php
@@ -33,6 +33,7 @@
              'REMOTE_USER',
              'REQUEST_METHOD',
              'REQUEST_URI',
+             'HTTP_X_EMPTY_HEADER',
          ] as $name) {
     echo "$name:" . $_SERVER[$name] . "\n";
 }
diff --git a/testdata/server-all-vars-ordered.txt b/testdata/server-all-vars-ordered.txt
@@ -30,4 +30,5 @@ QUERY_STRING:specialChars=%3E\x00%00</>
 REMOTE_USER:user
 REQUEST_METHOD:POST
 REQUEST_URI:/server-all-vars-ordered.php/path?specialChars=%3E\x00%00</>
+HTTP_X_EMPTY_HEADER:
 </pre>

Original file line number	Diff line number	Diff line change
`@@ -33,6 +33,7 @@`
`33`	`33`	`'REMOTE_USER',`
`34`	`34`	`'REQUEST_METHOD',`
`35`	`35`	`'REQUEST_URI',`
	`36`	`+ 'HTTP_X_EMPTY_HEADER',`
`36`	`37`	`] as $name) {`
`37`	`38`	`echo "$name:" . $_SERVER[$name] . "\n";`
`38`	`39`	`}`