feat: jwt expire 검증 누락 추가

Author: eckrin

Diff for: src/main/java/com/softeer/podoarrival/security/jwt/TokenProvider.java

@@ -14,6 +14,7 @@
 
 import java.text.ParseException;
 import java.util.Base64;
+import java.util.Date;
 
 @Component
 public class TokenProvider {
@@ -38,7 +39,14 @@ public JWTClaimsSet validateTokenAndGetClaimsSet(String token) {
                 throw new InvalidTokenException("Token signature is invalid");
             }
 
-            return signedJWT.getJWTClaimsSet();
+            JWTClaimsSet claimsSet = signedJWT.getJWTClaimsSet();
+            // expirationTime 검증
+            Date expirationTime = claimsSet.getExpirationTime();
+            if (expirationTime == null || expirationTime.before(new Date())) {
+                throw new InvalidTokenException("이미 만료된 토큰입니다.");
+            }
+
+            return claimsSet;
 
         } catch (JOSEException | ParseException e) {
             throw new InvalidTokenException("JWE Token Decoding Error - 토큰 검증과정에서 오류 발생");