feat: JWT 토큰 발급 기능 추가 (#39)

src/main/kotlin/kr/galaxyhub/sc/auth/config/JwtConfig.kt

@@ -0,0 +1,38 @@
+package kr.galaxyhub.sc.auth.config
+
+import io.jsonwebtoken.Jwts
+import io.jsonwebtoken.security.Keys
+import java.util.Date
+import java.util.concurrent.TimeUnit
+import kr.galaxyhub.sc.auth.domain.JwtExtractor
+import kr.galaxyhub.sc.auth.domain.JwtProvider
+import kr.galaxyhub.sc.auth.infra.JwtExtractorImpl
+import kr.galaxyhub.sc.auth.infra.JwtProviderImpl
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+
+@Configuration
+class JwtConfig(
+    @Value("\${galaxyhub.jwt.secret-key}") private val secretKey: String,
+) {
+
+    @Bean
+    fun jwtProvider(): JwtProvider {
+        val expirationMilliseconds: Long = TimeUnit.MINUTES.toMillis(30)
+        return JwtProviderImpl(
+            Keys.hmacShaKeyFor(secretKey.encodeToByteArray()),
+            ::Date, // == () -> new Date()
+            expirationMilliseconds,
+        )
+    }
+
+    @Bean
+    fun jwtExtractor(): JwtExtractor {
+        val jwtParser = Jwts.parser()
+            .clock(::Date)
+            .verifyWith(Keys.hmacShaKeyFor(secretKey.encodeToByteArray()))
+            .build()
+        return JwtExtractorImpl(jwtParser)
+    }
+}

src/main/kotlin/kr/galaxyhub/sc/auth/domain/JwtExtractor.kt

@@ -0,0 +1,8 @@
+package kr.galaxyhub.sc.auth.domain
+
+import java.util.UUID
+
+fun interface JwtExtractor {
+
+    fun parse(jwtToken: String): UUID
+}

src/main/kotlin/kr/galaxyhub/sc/auth/infra/JwtExtractorImpl.kt

@@ -0,0 +1,53 @@
+package kr.galaxyhub.sc.auth.infra
+
+import io.github.oshai.kotlinlogging.KotlinLogging
+import io.jsonwebtoken.Claims
+import io.jsonwebtoken.ExpiredJwtException
+import io.jsonwebtoken.JwtException
+import io.jsonwebtoken.JwtParser
+import java.util.UUID
+import kr.galaxyhub.sc.auth.domain.JwtExtractor
+import kr.galaxyhub.sc.common.exception.InternalServerError
+import kr.galaxyhub.sc.common.exception.UnauthorizedException
+
+private val log = KotlinLogging.logger {}
+
+class JwtExtractorImpl(
+    private val jwtParser: JwtParser,
+) : JwtExtractor {
+
+    override fun parse(jwtToken: String): UUID {
+        if (!jwtParser.isSigned(jwtToken)) { // Javadoc에 파싱 전 isSigned 메서드를 호출하는 것이 더 효율적이라고 하여 적용
+            throw UnauthorizedException("잘못된 형식의 JWT 토큰 입니다.")
+        }
+        val claims = extractClaims(jwtToken)
+        val memberId = getMemberIdFrom(claims)
+        return UUID.fromString(memberId)
+    }
+
+    private fun getMemberIdFrom(claims: Claims): String {
+        return (claims["memberId"] as? String)
+            ?: run {
+                log.error { "JWT 토큰 페이로드에 memberId가 없습니다. claims=$claims" }
+                throw InternalServerError("서버에서 JWT 토큰 파싱 중 문제가 발생했습니다.")
+            }
+    }
+
+    private fun extractClaims(jwtToken: String): Claims {
+        return runCatching { jwtParser.parseSignedClaims(jwtToken).payload }
+            .onFailure { handleJwtException(it) }
+            .getOrThrow()
+    }
+
+    private fun handleJwtException(it: Throwable) {
+        throw when (it) {
+            is ExpiredJwtException -> UnauthorizedException("만료된 JWT 토큰 입니다.")
+            is JwtException, is IllegalArgumentException -> UnauthorizedException("잘못된 형식의 JWT 토큰 입니다.")
+            else -> {
+                log.error(it) { "서버에서 JWT 토큰 파싱 중 문제가 발생했습니다." }
+                it
+            }
+        }
+    }
+}
+

src/main/kotlin/kr/galaxyhub/sc/auth/infra/JwtProviderImpl.kt

@@ -1,14 +1,25 @@
 package kr.galaxyhub.sc.auth.infra
 
+import io.jsonwebtoken.Clock
+import io.jsonwebtoken.Jwts
+import java.util.Date
+import javax.crypto.SecretKey
 import kr.galaxyhub.sc.auth.domain.JwtProvider
 import kr.galaxyhub.sc.member.domain.Member
-import org.springframework.stereotype.Component
 
-@Component
-class JwtProviderImpl : JwtProvider {
+class JwtProviderImpl(
+    private val secretKey: SecretKey,
+    private val clock: Clock,
+    private val expirationMilliseconds: Long,
+) : JwtProvider {
 
     override fun provide(member: Member): String {
-        // TODO 새로운 이슈로 만들어 기능 추가할 것
-        return "accessToken"
+        val now = clock.now()
+        return Jwts.builder()
+            .signWith(secretKey)
+            .claim("memberId", member.id)
+            .issuedAt(now)
+            .expiration(Date(now.time + expirationMilliseconds))
+            .compact()
     }
 }

src/main/kotlin/kr/galaxyhub/sc/common/exception/GalaxyhubException.kt

@@ -3,7 +3,7 @@ package kr.galaxyhub.sc.common.exception
 import kr.galaxyhub.sc.common.support.LogLevel
 import org.springframework.http.HttpStatusCode
 
-open class GalaxyhubException(
+sealed class GalaxyhubException(
     message: String,
     val httpStatus: HttpStatusCode,
     val logLevel: LogLevel,

src/main/kotlin/kr/galaxyhub/sc/common/exception/UnauthorizedException.kt

@@ -0,0 +1,11 @@
+package kr.galaxyhub.sc.common.exception
+
+import kr.galaxyhub.sc.common.support.LogLevel
+import org.springframework.http.HttpStatus
+import org.springframework.http.HttpStatusCode
+
+class UnauthorizedException(
+    message: String,
+    httpStatus: HttpStatusCode = HttpStatus.UNAUTHORIZED,
+    logLevel: LogLevel = LogLevel.INFO,
+) : GalaxyhubException(message, httpStatus, logLevel)

src/main/resources/application-local.yml

@@ -26,3 +26,5 @@ galaxyhub:
       client_id: 123123
       client_secret: 123123
       redirect_uri: http://localhost:8080/api/v1/auth/oauth2/login?socialType=discord
+  jwt:
+    secret-key: galaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhub

src/test/kotlin/kr/galaxyhub/sc/auth/infra/JwtExtractorImplTest.kt

@@ -0,0 +1,106 @@
+package kr.galaxyhub.sc.auth.infra
+
+import io.jsonwebtoken.Jwts
+import io.jsonwebtoken.security.Keys
+import io.kotest.assertions.throwables.shouldThrow
+import io.kotest.core.spec.style.DescribeSpec
+import io.kotest.matchers.shouldBe
+import io.kotest.matchers.throwable.shouldHaveMessage
+import java.time.Instant
+import java.util.Date
+import java.util.UUID
+import kr.galaxyhub.sc.common.exception.InternalServerError
+import kr.galaxyhub.sc.common.exception.UnauthorizedException
+
+class JwtExtractorImplTest : DescribeSpec({
+
+    val secretKey = Keys.hmacShaKeyFor("galaxyhub".repeat(10).encodeToByteArray())
+    val otherKey = Keys.hmacShaKeyFor("seokjin8678".repeat(10).encodeToByteArray())
+    val now = Date.from(Instant.parse("2023-12-20T17:09:00Z"))
+
+    describe("parse") {
+        val jwtExtractor = JwtExtractorImpl(
+            Jwts.parser()
+                .verifyWith(secretKey)
+                .clock { now }
+                .build()
+        )
+
+        context("유효하지 않은 JWT 토큰이면") {
+            val token = ""
+
+            it("UnauthorizedException 예외를 던진다.") {
+                val ex = shouldThrow<UnauthorizedException> {
+                    jwtExtractor.parse(token)
+                }
+                ex shouldHaveMessage "잘못된 형식의 JWT 토큰 입니다."
+            }
+        }
+
+        context("JWT 토큰이 만료되면") {
+            val token = Jwts.builder()
+                .signWith(secretKey)
+                .expiration(Date(now.time - 1_000))
+                .compact()
+
+            it("UnauthorizedException 예외를 던진다.") {
+                val ex = shouldThrow<UnauthorizedException> {
+                    jwtExtractor.parse(token)
+                }
+                ex shouldHaveMessage "만료된 JWT 토큰 입니다."
+            }
+        }
+
+        context("JWT 토큰이 서명 되지 않으면") {
+            val token = Jwts.builder()
+                .compact()
+
+            it("UnauthorizedException 예외를 던진다.") {
+                val ex = shouldThrow<UnauthorizedException> {
+                    jwtExtractor.parse(token)
+                }
+                ex shouldHaveMessage "잘못된 형식의 JWT 토큰 입니다."
+            }
+        }
+
+        context("JWT 토큰이 다른 secretKey로 서명 되면") {
+            val token = Jwts.builder()
+                .signWith(otherKey)
+                .compact()
+
+            it("UnauthorizedException 예외를 던진다.") {
+                val ex = shouldThrow<UnauthorizedException> {
+                    jwtExtractor.parse(token)
+                }
+                ex shouldHaveMessage "잘못된 형식의 JWT 토큰 입니다."
+            }
+        }
+
+        context("JWT 토큰에 memberId 페이로드가 없으면") {
+            val token = Jwts.builder()
+                .signWith(secretKey)
+                .expiration((Date(now.time + 1_000)))
+                .compact()
+
+            it("InternalServerError 예외를 던진다.") {
+                val ex = shouldThrow<InternalServerError> {
+                    jwtExtractor.parse(token)
+                }
+                ex shouldHaveMessage "서버에서 JWT 토큰 파싱 중 문제가 발생했습니다."
+            }
+        }
+
+        context("JWT 토큰이 유효하면") {
+            val memberId = UUID.randomUUID()
+            val token = Jwts.builder()
+                .claim("memberId", memberId)
+                .signWith(secretKey)
+                .expiration((Date(now.time + 1_000)))
+                .compact()
+
+            it("memberId가 반환된다.") {
+                jwtExtractor.parse(token) shouldBe memberId
+            }
+        }
+    }
+})

src/test/kotlin/kr/galaxyhub/sc/auth/infra/JwtProviderImplTest.kt

@@ -0,0 +1,47 @@
+package kr.galaxyhub.sc.auth.infra
+
+import io.jsonwebtoken.Jwts
+import io.jsonwebtoken.security.Keys
+import io.kotest.assertions.throwables.shouldNotThrow
+import io.kotest.assertions.throwables.shouldThrow
+import io.kotest.core.spec.style.DescribeSpec
+import java.time.Instant
+import java.util.Date
+import java.util.concurrent.TimeUnit
+import kr.galaxyhub.sc.member.domain.Member
+import kr.galaxyhub.sc.member.domain.SocialType
+
+class JwtProviderImplTest : DescribeSpec({
+
+    val secretKey = Keys.hmacShaKeyFor("galaxyhub".repeat(10).encodeToByteArray())
+    val otherKey = Keys.hmacShaKeyFor("seokjin8678".repeat(10).encodeToByteArray())
+    val now = Date.from(Instant.parse("2023-12-20T17:09:00Z"))
+
+    describe("provide") {
+        val jwtProvider = JwtProviderImpl(secretKey, { now }, TimeUnit.MINUTES.toMillis(30))
+
+        context("secretKey로 JWT 토큰을 생성하면") {
+            val member = Member("1", SocialType.LOCAL, "seokjin8678", null, null)
+
+            val token = jwtProvider.provide(member)
+
+            it("토큰은 secretKey로 검증할 수 있다.") {
+                val jwtParser = Jwts.parser()
+                    .verifyWith(secretKey)
+                    .clock { now }
+                    .build()
+
+                shouldNotThrow<Exception> { jwtParser.parseSignedClaims(token) }
+            }
+
+            it("토큰은 다른 secretKey로 검증할 수 없다.") {
+                val otherParser = Jwts.parser()
+                    .verifyWith(otherKey)
+                    .clock { now }
+                    .build()
+
+                shouldThrow<Exception> { otherParser.parseSignedClaims(token) }
+            }
+        }
+    }
+})

src/test/resources/application-test.yml

@@ -24,3 +24,5 @@ galaxyhub:
       client_id: discord_id
       client_secret: discord_client_secret
       redirect_uri: http://localhost:8080/api/v1/auth/oauth2/code?provider=discord
+  jwt:
+    secret-key: galaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhubgalaxyhub