fix: companion when custom CORS *-Origin is set

Companion extension should be able to access RPC API even when custom
Access-Control-Allow-Origin is set

Author: lidel

core/corehttp/commands.go

@@ -44,6 +44,9 @@ var defaultLocalhostOrigins = []string{
 	"https://[::1]:<port>",
 	"http://localhost:<port>",
 	"https://localhost:<port>",
+}
+
+var companionBrowserExtensionOrigins = []string{
 	"chrome-extension://nibjojkomfdiaoajekhjakgkdhaomnch", // ipfs-companion
 	"chrome-extension://hjoieblefckbooibpepigmacodalfndh", // ipfs-companion-beta
 }
@@ -86,10 +89,9 @@ func addHeadersFromConfig(c *cmdsHttp.ServerConfig, nc *config.Config) {
 }
 
 func addCORSDefaults(c *cmdsHttp.ServerConfig) {
-	// by default use localhost origins
-	if len(c.AllowedOrigins()) == 0 {
-		c.SetAllowedOrigins(defaultLocalhostOrigins...)
-	}
+	// always safelist certain origins
+	c.AppendAllowedOrigins(defaultLocalhostOrigins...)
+	c.AppendAllowedOrigins(companionBrowserExtensionOrigins...)
 
 	// by default, use GET, PUT, POST
 	if len(c.AllowedMethods()) == 0 {

test/sharness/t0401-api-browser-security.sh

@@ -39,17 +39,18 @@ test_expect_success "browser is able to access API if Origin is the API port on
   grep "HTTP/1.1 200 OK" curl_output && grep "$PEERID" curl_output
 '
 
-test_expect_success "Companion extension is unable to access API with invalid Origin" '
+test_expect_success "Random browser extension is unable to access RPC API due to invalid Origin" '
   curl -sD - -X POST -A "Mozilla" -H "Origin: chrome-extension://invalidextensionid" "http://127.0.0.1:$API_PORT/api/v0/id" >curl_output &&
   grep "HTTP/1.1 403 Forbidden" curl_output
 '
 
-test_expect_success "Companion extension is able to access API if Origin is the API port on localhost (ipv4)" '
+test_expect_success "Companion extension is able to access RPC API on localhost" '
   curl -sD - -X POST -A "Mozilla" -H "Origin: chrome-extension://nibjojkomfdiaoajekhjakgkdhaomnch" "http://127.0.0.1:$API_PORT/api/v0/id" >curl_output &&
+  cat curl_output &&
   grep "HTTP/1.1 200 OK" curl_output && grep "$PEERID" curl_output
 '
 
-test_expect_success "Companion beta extension is able to access API if Origin is the API port on localhost (ipv4)" '
+test_expect_success "Companion beta extension is able to access API on localhost" '
   curl -sD - -X POST -A "Mozilla" -H "Origin: chrome-extension://hjoieblefckbooibpepigmacodalfndh" "http://127.0.0.1:$API_PORT/api/v0/id" >curl_output &&
   grep "HTTP/1.1 200 OK" curl_output && grep "$PEERID" curl_output
 '
@@ -64,6 +65,13 @@ test_expect_success "setting CORS in API.HTTPHeaders works via CLI" "
 
 test_launch_ipfs_daemon
 
+test_expect_success "Companion extension is able to access RPC API even when custom Access-Control-Allow-Origin is set" '
+  curl -sD - -X POST -A "Mozilla" -H "Origin: chrome-extension://nibjojkomfdiaoajekhjakgkdhaomnch" "http://127.0.0.1:$API_PORT/api/v0/id" >curl_output &&
+  cat curl_output &&
+  grep "HTTP/1.1 200 OK" curl_output &&
+  grep "$PEERID" curl_output
+'
+
 # https://developer.mozilla.org/en-US/docs/Glossary/Preflight_request
 test_expect_success "OPTIONS with preflight request to API with CORS allowlist succeeds" '
   curl -svX OPTIONS -A "Mozilla" -H "Origin: https://valid.example.com" -H "Access-Control-Request-Method: POST" -H "Access-Control-Request-Headers: origin, x-requested-with" "http://127.0.0.1:$API_PORT/api/v0/id" 2>curl_output &&