[FEAT] 로그인 기능 구현 (#195)

* feat: 로그인 입력 받아오는 DTO 생성

* feat(PasswordEncoder): 주석 추가 및 비밀 번호 검증 로직 구현

* feat(MemberService): 로그인 정보로 멤버 조회 및 비밀번호 검증 로직 구현

* feat(MemberService): 비밀번호 불일치 예외 처리

* feat(AuthService): 입력 받은 로그인 정보로 JWT 토큰 방식 로그인 구현

* feat(AuthController): 로그인 정보 입력 받는 컨트롤러 구현

* feat(Auth): refreshToken 재발급 서비스 및 컨트롤러 구현

* feat(AuthService): @transactional 적용

src/main/java/econo/buddybridge/auth/controller/AuthController.java

@@ -1,5 +1,8 @@
 package econo.buddybridge.auth.controller;
 
+import econo.buddybridge.auth.dto.LoginReqDto;
+import econo.buddybridge.auth.jwt.AuthToken;
+import econo.buddybridge.auth.resolver.MemberToken;
 import econo.buddybridge.auth.service.AuthService;
 import econo.buddybridge.common.annotation.AllowAnonymous;
 import econo.buddybridge.member.dto.MemberSignUpReqDto;
@@ -34,4 +37,21 @@ public ApiResponse<CustomBody<MemberSignUpResDto>> signUp(
         MemberSignUpResDto memberSignUpResDto = authService.signUp(memberSignUpReqDto);
         return ApiResponseGenerator.success(memberSignUpResDto, HttpStatus.OK);
     }
+
+    @Operation(summary = "자체 로그인 (JWT)", description = "이메일과 비밀번호를 이용해 JWT 토큰을 발급합니다.")
+    @PostMapping("/login")
+    @AllowAnonymous
+    public ApiResponse<CustomBody<AuthToken>> login(
+            @Valid @RequestBody LoginReqDto params
+    ) {
+        AuthToken authToken = authService.loginWithToken(params);
+        return ApiResponseGenerator.success(authToken, HttpStatus.OK);
+    }
+
+    @Operation(summary = "Access Token, Refresh Token 재발급", description = "Refresh Token을 이용해 Access Token과 Refresh Token을 재발급합니다.")
+    @PostMapping("/reissue")
+    public ApiResponse<CustomBody<AuthToken>> reissue(@MemberToken String token) {
+        AuthToken authToken = authService.reissue(token);
+        return ApiResponseGenerator.success(authToken, HttpStatus.OK);
+    }
 }

src/main/java/econo/buddybridge/auth/dto/LoginReqDto.java

@@ -0,0 +1,15 @@
+package econo.buddybridge.auth.dto;
+
+import jakarta.validation.constraints.Email;
+import jakarta.validation.constraints.NotBlank;
+
+public record LoginReqDto(
+        @NotBlank(message = "이메일을 입력해주세요.")
+        @Email(message = "이메일 형식이 올바르지 않습니다.")
+        String email,
+
+        @NotBlank(message = "비밀번호를 입력해주세요.")
+        String password
+) {
+
+}

src/main/java/econo/buddybridge/auth/service/AuthService.java

@@ -1,18 +1,36 @@
 package econo.buddybridge.auth.service;
 
+import econo.buddybridge.auth.dto.LoginReqDto;
+import econo.buddybridge.auth.jwt.AuthToken;
+import econo.buddybridge.auth.jwt.service.AuthTokenService;
+import econo.buddybridge.member.dto.MemberResDto;
 import econo.buddybridge.member.dto.MemberSignUpReqDto;
 import econo.buddybridge.member.dto.MemberSignUpResDto;
 import econo.buddybridge.member.service.MemberService;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
 
 @Service
 @RequiredArgsConstructor
 public class AuthService {
 
     private final MemberService memberService;
+    private final AuthTokenService authTokenService;
 
+    @Transactional
     public MemberSignUpResDto signUp(MemberSignUpReqDto memberSignUpReqDto) {
         return memberService.createSignUpMember(memberSignUpReqDto);
     }
+
+    @Transactional
+    public AuthToken loginWithToken(LoginReqDto params) {
+        MemberResDto member = memberService.findMemberByEmailAndPassword(params);
+        return authTokenService.generateAuthToken(member.memberId());
+    }
+
+    @Transactional
+    public AuthToken reissue(String refreshToken) {
+        return authTokenService.reissue(refreshToken);
+    }
 }

src/main/java/econo/buddybridge/auth/utils/PasswordEncoder.java

@@ -8,6 +8,7 @@
 
 import javax.crypto.SecretKeyFactory;
 import javax.crypto.spec.PBEKeySpec;
+import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.security.spec.InvalidKeySpecException;
@@ -17,6 +18,16 @@
 @Slf4j
 @Component
 public class PasswordEncoder {
+
+    /*
+     * 사용자가 입력한 비밀번호, 저장된 비밀번호(해싱됨), 저장된 솔트(암호화) 를 입력 받아
+     * 비밀번호의 일치 여부를 확인합니다.
+     * */
+    public boolean verify(String password, String storedPassword, String storedSalt) {
+        byte[] salt = Base64.getDecoder().decode(storedSalt);
+        String hashedKey = hashPassword(password, salt);
+        return MessageDigest.isEqual(storedPassword.getBytes(), hashedKey.getBytes());
+    }
 
     public PasswordHashDto encrypt(String password) {
         byte[] salt = generateRandomSalt();
@@ -26,6 +37,9 @@ public PasswordHashDto encrypt(String password) {
         return new PasswordHashDto(hashedPassword, saltString);
     }
 
+    /*
+     * 사용자가 입력한 비밀번호와 솔트를 이용해 해싱된 비밀번호를 반환합니다.
+     * */
     private String hashPassword(String password, byte[] salt) {
         try {
             KeySpec spec = new PBEKeySpec(password.toCharArray(), salt, 10000, 128);
@@ -38,6 +52,10 @@ private String hashPassword(String password, byte[] salt) {
         }
     }
 
+    /*
+     * 솔트를 생성합니다
+     * 솔트 : 암호화된 비밀번호를 해독하는데 사용되는 임의의 바이트 배열
+     * */
     private byte[] generateRandomSalt() {
         try {
             SecureRandom random = new SecureRandom();

src/main/java/econo/buddybridge/member/exception/InvalidPasswordException.java

@@ -0,0 +1,12 @@
+package econo.buddybridge.member.exception;
+
+import econo.buddybridge.common.exception.BusinessException;
+
+public class InvalidPasswordException extends BusinessException {
+
+    public static BusinessException EXCEPTION = new InvalidPasswordException();
+
+    private InvalidPasswordException() {
+        super(MemberErrorCode.INVALID_PASSWORD);
+    }
+}

src/main/java/econo/buddybridge/member/exception/MemberErrorCode.java

@@ -6,7 +6,7 @@
 public enum MemberErrorCode implements ErrorCode {
     MEMBER_NOT_FOUND("M001", HttpStatus.NOT_FOUND, "존재하지 않는 회원입니다."),
     MEMBER_EMAIL_ALREADY_EXISTS("M002", HttpStatus.BAD_REQUEST, "이미 사용중인 이메일입니다."),
-    ;
+    INVALID_PASSWORD("M003", HttpStatus.UNAUTHORIZED, "비밀번호가 일치하지 않습니다.");
 
     private final String code;
     private final HttpStatus httpStatus;

src/main/java/econo/buddybridge/member/service/MemberService.java

@@ -1,5 +1,6 @@
 package econo.buddybridge.member.service;
 
+import econo.buddybridge.auth.dto.LoginReqDto;
 import econo.buddybridge.auth.dto.PasswordHashDto;
 import econo.buddybridge.auth.dto.kakao.UserInfoWithKakaoToken;
 import econo.buddybridge.auth.utils.PasswordEncoder;
@@ -9,6 +10,7 @@
 import econo.buddybridge.member.dto.MemberSignUpResDto;
 import econo.buddybridge.member.entity.DisabilityType;
 import econo.buddybridge.member.entity.Member;
+import econo.buddybridge.member.exception.InvalidPasswordException;
 import econo.buddybridge.member.exception.MemberEmailAlreadyExistsException;
 import econo.buddybridge.member.exception.MemberNotFoundException;
 import econo.buddybridge.member.repository.MemberRepository;
@@ -97,4 +99,15 @@ private void signUpMember(MemberSignUpReqDto memberSignUpReqDto) {
         memberRepository.save(member);
     }
 
+    @Transactional
+    public MemberResDto findMemberByEmailAndPassword(LoginReqDto loginReqDto) {
+        Member member = memberRepository.findByEmail(loginReqDto.email())
+                .orElseThrow(() -> MemberNotFoundException.EXCEPTION);
+
+        if (!passwordEncoder.verify(loginReqDto.password(), member.getPassword(), member.getSalt())) {
+            throw InvalidPasswordException.EXCEPTION;
+        }
+
+        return new MemberResDto(member);
+    }
 }