[PM-39840] fix: Use dedicated OkHttpClient for fill-assist to prevent load-balancer prompt (#7131)

network/src/main/kotlin/com/bitwarden/network/retrofit/RetrofitsImpl.kt

@@ -67,7 +67,7 @@ internal class RetrofitsImpl(
     //region Fill-Assist Retrofit
 
     override val fillAssistRetrofit: Retrofit by lazy {
-        createUnauthenticatedRetrofit(
+        createExternalRetrofit(
             baseUrlInterceptor = baseUrlInterceptors.fillAssistInterceptor,
         )
     }
@@ -111,6 +111,14 @@ internal class RetrofitsImpl(
         .configureSsl(certificateProvider = certificateProvider)
         .build()
 
+    // For requests to external (non-Bitwarden) URLs. CookieInterceptor must be excluded because
+    // it treats all 302s as Bitwarden load-balancer auth redirects, which is only correct for
+    // Bitwarden's own infrastructure.
+    private val externalOkHttpClient: OkHttpClient = OkHttpClient.Builder()
+        .addInterceptor(headersInterceptor)
+        .configureSsl(certificateProvider = certificateProvider)
+        .build()
+
     private val authenticatedOkHttpClient: OkHttpClient by lazy {
         baseOkHttpClient
             .newBuilder()
@@ -162,5 +170,20 @@ internal class RetrofitsImpl(
             )
             .build()
 
+    private fun createExternalRetrofit(
+        baseUrlInterceptor: BaseUrlInterceptor,
+    ): Retrofit =
+        baseRetrofit
+            .newBuilder()
+            .client(
+                externalOkHttpClient
+                    .newBuilder()
+                    .addInterceptor(baseUrlInterceptor)
+                    .addInterceptor(loggingInterceptor)
+                    .addInterceptor(permissionInterceptor)
+                    .build(),
+            )
+            .build()
+
     //endregion Helper properties and functions
 }

network/src/test/kotlin/com/bitwarden/network/retrofit/RetrofitsTest.kt

@@ -47,6 +47,9 @@ class RetrofitsTest {
         every { eventsInterceptor } returns mockk {
             mockIntercept { isEventsInterceptorCalled = true }
         }
+        every { fillAssistInterceptor } returns mockk {
+            mockIntercept { isFillAssistInterceptorCalled = true }
+        }
     }
     private val cookieInterceptor = mockk<CookieInterceptor> {
         mockIntercept { isCookieInterceptorCalled = true }
@@ -82,6 +85,7 @@ class RetrofitsTest {
     private var isHeadersInterceptorCalled = false
     private var isIdentityInterceptorCalled = false
     private var isEventsInterceptorCalled = false
+    private var isFillAssistInterceptorCalled = false
     private var isRefreshAuthenticatorCalled = false
 
     @Before
@@ -248,6 +252,27 @@ class RetrofitsTest {
         assertFalse(isEventsInterceptorCalled)
     }
 
+    @Test
+    fun `fillAssistRetrofit should invoke the correct interceptors`() = runBlocking {
+        val testApi = retrofits
+            .fillAssistRetrofit
+            .createMockRetrofit()
+            .create<TestApi>()
+
+        server.enqueue(MockResponse().setBody("""{}"""))
+
+        testApi.test()
+
+        assertFalse(isAuthInterceptorCalled)
+        assertFalse(isApiInterceptorCalled)
+        assertFalse(isCookieInterceptorCalled)
+        assertTrue(isPermissionInterceptorCalled)
+        assertTrue(isHeadersInterceptorCalled)
+        assertFalse(isIdentityInterceptorCalled)
+        assertFalse(isEventsInterceptorCalled)
+        assertTrue(isFillAssistInterceptorCalled)
+    }
+
     @Test
     fun `createStaticRetrofit when authenticated should invoke the correct interceptors`() =
         runBlocking {
@@ -312,7 +337,7 @@ class RetrofitsTest {
 
             retrofits.createStaticRetrofit()
 
-            verify(exactly = 1) {
+            verify(exactly = 2) {
                 anyConstructed<OkHttpClient.Builder>().sslSocketFactory(any(), any())
             }
         }