refactor: 회원가입 토큰 검증 시, 서버에 저장된 값과 동일한지 검증 추가

- code rabbit 리뷰 반영: #479 (comment)

Author: nayonsoso

src/main/java/com/example/solidconnection/auth/controller/AuthController.java

@@ -10,10 +10,10 @@
 import com.example.solidconnection.auth.dto.oauth.OAuthResponse;
 import com.example.solidconnection.auth.dto.oauth.OAuthSignInResponse;
 import com.example.solidconnection.auth.service.AuthService;
+import com.example.solidconnection.auth.service.oauth.OAuthService;
 import com.example.solidconnection.auth.service.signin.EmailSignInService;
 import com.example.solidconnection.auth.service.signup.EmailSignUpTokenProvider;
 import com.example.solidconnection.auth.service.signup.SignUpService;
-import com.example.solidconnection.auth.service.oauth.OAuthService;
 import com.example.solidconnection.common.exception.CustomException;
 import com.example.solidconnection.common.exception.ErrorCode;
 import com.example.solidconnection.common.resolver.AuthorizedUser;

src/main/java/com/example/solidconnection/auth/service/signup/SignUpTokenProvider.java

@@ -1,7 +1,6 @@
 package com.example.solidconnection.auth.service.signup;
 
 import static com.example.solidconnection.common.exception.ErrorCode.SIGN_UP_TOKEN_INVALID;
-import static com.example.solidconnection.common.exception.ErrorCode.SIGN_UP_TOKEN_NOT_ISSUED_BY_SERVER;
 
 import com.example.solidconnection.auth.domain.SignUpToken;
 import com.example.solidconnection.auth.domain.Subject;
@@ -41,8 +40,7 @@ public void deleteByEmail(String email) {
 
     public void validateSignUpToken(String token) {
         validateFormatAndExpiration(token);
-        String email = parseEmail(token);
-        validateIssuedByServer(email);
+        validateIssuedByServer(token);
     }
 
     private void validateFormatAndExpiration(String token) { // 파싱되는지, AuthType이 포함되어있는지 검증
@@ -54,9 +52,11 @@ private void validateFormatAndExpiration(String token) { // 파싱되는지, Aut
         }
     }
 
-    private void validateIssuedByServer(String email) {
+    private void validateIssuedByServer(String token) {
+        String email = parseEmail(token);
         tokenStorage.findToken(new Subject(email), SignUpToken.class)
-                .orElseThrow(() -> new CustomException(SIGN_UP_TOKEN_NOT_ISSUED_BY_SERVER));
+                .filter(foundToken -> foundToken.equals(token))
+                .orElseThrow(() -> new CustomException(SIGN_UP_TOKEN_INVALID));
     }
 
     public String parseEmail(String token) {