Feat: TURN 서버 동적 인증 정보 생성 기능 구현

Author: jueunk617

src/main/java/com/back/global/websocket/webrtc/controller/WebRTCApiController.java

@@ -9,11 +9,16 @@
 import io.swagger.v3.oas.annotations.tags.Tag;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Base64;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
-
 import java.util.List;
 
 @Slf4j
@@ -26,6 +31,15 @@ public class WebRTCApiController {
 
     private final WebRTCProperties webRTCProperties;
 
+    @Value("${webrtc.turn.shared-secret}")
+    private String turnSharedSecret;
+
+    @Value("${webrtc.turn.server-ip}")
+    private String turnServerIp;
+
+    @Value("${webrtc.turn.ttl-seconds}")
+    private long turnTtlSeconds;
+
     @GetMapping("/ice-servers")
     @Operation(summary = "ICE 서버 설정 조회")
     public ResponseEntity<RsData<IceServerConfig>> getIceServers(
@@ -34,13 +48,35 @@ public ResponseEntity<RsData<IceServerConfig>> getIceServers(
 
         log.info("ICE 서버 설정 요청 - userId: {}, roomId: {}", userId, roomId);
 
-        List<IceServer> iceServers =
+        List<IceServer> iceServers = new ArrayList<>(
                 webRTCProperties.iceServers().stream()
                         .map(s -> new IceServer(s.urls(), s.username(), s.credential()))
-                        .toList();
+                        .toList()
+        );
 
-        IceServerConfig config = new IceServerConfig(iceServers);
+        // 동적으로 시간제한이 있는 TURN 서버 인증 정보 생성
+        try {
+            // 유효기간 타임스탬프를 생성 (현재 시간 + TTL)
+            long expiry = (System.currentTimeMillis() / 1000) + turnTtlSeconds;
+            String username = String.valueOf(expiry);
 
+            // HMAC-SHA1 알고리즘과 공유 비밀키를 사용하여 비밀번호(credential) 생성
+            Mac sha1Hmac = Mac.getInstance("HmacSHA1");
+            SecretKeySpec secretKey = new SecretKeySpec(turnSharedSecret.getBytes(StandardCharsets.UTF_8), "HmacSHA1");
+            sha1Hmac.init(secretKey);
+            byte[] hmacBytes = sha1Hmac.doFinal(username.getBytes(StandardCharsets.UTF_8));
+            String credential = Base64.getEncoder().encodeToString(hmacBytes);
+
+            // 생성된 TURN 서버 정보를 리스트에 추가
+            String turnUrl = "turn:" + turnServerIp + ":3478";
+            iceServers.add(IceServer.turn(turnUrl, username, credential));
+
+        } catch (Exception e) {
+            log.error("TURN 서버 동적 인증 정보 생성에 실패했습니다. STUN 서버만으로 응답합니다.", e);
+            // 인증 정보 생성에 실패하더라도, STUN 서버만으로라도 서비스가 동작하도록 예외를 던지지 않음
+        }
+
+        IceServerConfig config = new IceServerConfig(iceServers);
         log.info("ICE 서버 설정 제공 완료 - STUN/TURN 서버 {}개", config.iceServers().size());
 
         return ResponseEntity

src/test/java/com/back/global/websocket/webrtc/controller/WebRTCApiControllerTest.java

@@ -9,6 +9,7 @@
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.http.MediaType;
 import org.springframework.security.test.context.support.WithMockUser;
+import org.springframework.test.context.TestPropertySource;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.MvcResult;
 
@@ -20,6 +21,11 @@
 @SpringBootTest
 @AutoConfigureMockMvc
 @WithMockUser
+@TestPropertySource(properties = {
+        "webrtc.turn.shared-secret=test-secret-key-for-junit-12345",
+        "webrtc.turn.server-ip=127.0.0.1"
+        // ttl-seconds는 application.yml의 기본값 사용
+})
 @DisplayName("WebRTC API 컨트롤러")
 class WebRTCApiControllerTest {
 
@@ -34,7 +40,7 @@ class WebRTCApiControllerTest {
     class GetIceServersTest {
 
         @Test
-        @DisplayName("기본 조회")
+        @DisplayName("STUN 서버와 동적으로 생성된 TURN 서버 정보를 모두 포함하여 반환")
         void t1() throws Exception {
             // when & then
             MvcResult result = mockMvc.perform(get("/api/webrtc/ice-servers")
@@ -47,13 +53,17 @@ void t1() throws Exception {
                     .andExpect(jsonPath("$.data").exists())
                     .andExpect(jsonPath("$.data.iceServers").isArray())
                     .andExpect(jsonPath("$.data.iceServers").isNotEmpty())
+                    .andExpect(jsonPath("$.data.iceServers[?(@.urls contains 'turn:')].urls").exists())
+                    .andExpect(jsonPath("$.data.iceServers[?(@.urls contains 'turn:')].username").exists())
+                    .andExpect(jsonPath("$.data.iceServers[?(@.urls contains 'turn:')].credential").exists())
                     .andReturn();
 
-            // 응답 본문 검증
             String content = result.getResponse().getContentAsString();
             assertThat(content).contains("stun:");
+            assertThat(content).contains("turn:");
         }
 
+
         @Test
         @DisplayName("userId, roomId 파라미터")
         void t2() throws Exception {