feat: 카카오 로그인 기본 기능

- 추후 검증 추가 예정

Related to: #16

src/main/java/com/umc5th/muffler/domain/member/service/KakaoService.java

@@ -0,0 +1,25 @@
+package com.umc5th.muffler.domain.member.service;
+
+import com.umc5th.muffler.global.security.jwt.JwtOICDProvider;
+import io.jsonwebtoken.Claims;
+import io.jsonwebtoken.Header;
+import io.jsonwebtoken.Jwt;
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class KakaoService {
+
+    private final String ISS = "https://kauth.kakao.com";
+    @Value("${jwt.aud}")
+    private String AUD;
+
+    private final JwtOICDProvider jwtOICDProvider;
+
+    public String login(String idToken) {
+        Jwt<Header, Claims> jwt = jwtOICDProvider.getUnsignedTokenClaims(idToken, ISS, AUD);
+        return jwt.getBody().getSubject();
+    }
+}

src/main/java/com/umc5th/muffler/domain/member/service/MemberService.java

@@ -34,6 +34,7 @@ public class MemberService {
 
     private final MemberRepository memberRepository;
     private final AppleService appleService;
+    private final KakaoService kakaoService;
     private final JwtTokenUtils jwtTokenUtils;
     private final BatchUpdateCategoryRepository batchUpdateCategoryRepository;
     private final EntityManager entityManager;
@@ -79,6 +80,9 @@ private String socialLogin(LoginRequest request) {
         if (request.getSocialType() == SocialType.APPLE) {
             return appleService.login(request);
         }
+        if (request.getSocialType() == SocialType.KAKAO) {
+            return kakaoService.login(request.getIdToken());
+        }
         throw new CommonException(BAD_REQUEST, "지원하지 않는 소셜 로그인 입니다.");
     }
 

src/main/java/com/umc5th/muffler/global/security/jwt/JwtOICDProvider.java

@@ -0,0 +1,40 @@
+package com.umc5th.muffler.global.security.jwt;
+
+import static com.umc5th.muffler.global.response.code.ErrorCode.INVALID_TOKEN;
+
+import com.umc5th.muffler.global.response.exception.CommonException;
+import io.jsonwebtoken.Claims;
+import io.jsonwebtoken.ExpiredJwtException;
+import io.jsonwebtoken.Header;
+import io.jsonwebtoken.Jwt;
+import io.jsonwebtoken.Jwts;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+
+@Slf4j
+@Component
+public class JwtOICDProvider {
+    private String getUnsignedToken(String token) {
+        String[] splitToken = token.split("\\.");
+        if (splitToken.length != 3) {
+            throw new CommonException(INVALID_TOKEN, "Invalid KakaoIdToken");
+        }
+        return splitToken[0] + "." + splitToken[1] + ".";
+    }
+
+    public Jwt<Header, Claims> getUnsignedTokenClaims(String token, String iss, String aud) {
+        try {
+            return Jwts.parserBuilder()
+                    .requireAudience(aud)
+                    .requireIssuer(iss)
+                    .build()
+                    .parseClaimsJwt(getUnsignedToken(token));
+        } catch (ExpiredJwtException e) {
+            log.error("Expired JWT Token", e);
+            throw new CommonException(INVALID_TOKEN, "Expired JWT Token");
+        } catch (Exception e) {
+            log.error(e.toString());
+            throw new CommonException(INVALID_TOKEN, "Invalid KakaoIdToken");
+        }
+    }
+}

src/main/resources/application.yml

@@ -73,6 +73,8 @@ spring:
             enable: true
 jwt:
   secret: ${JWT_SECRET}
+  aud: ${JWT_AUD}
+
 server:
   servlet:
     encoding: