Refactor jwt

domain/src/security/JwtMapper.kt

@@ -0,0 +1,30 @@
+package be.simplenotes.domain.security
+
+import be.simplenotes.types.LoggedInUser
+import com.auth0.jwt.JWTCreator
+import com.auth0.jwt.interfaces.DecodedJWT
+import javax.inject.Singleton
+
+interface JwtMapper<T> {
+    fun extract(decodedJWT: DecodedJWT): T?
+    fun build(builder: JWTCreator.Builder, value: T)
+}
+
+@Singleton
+class UserJwtMapper : JwtMapper<LoggedInUser> {
+    private val userIdField = "i"
+    private val usernameField = "u"
+
+    override fun extract(decodedJWT: DecodedJWT): LoggedInUser? {
+        val id = decodedJWT.getClaim(userIdField).asInt() ?: null
+        val username = decodedJWT.getClaim(usernameField).asString() ?: null
+        return if (id != null && username != null)
+            LoggedInUser(id, username)
+        else null
+    }
+
+    override fun build(builder: JWTCreator.Builder, value: LoggedInUser) {
+        builder.withClaim(userIdField, value.userId)
+            .withClaim(usernameField, value.username)
+    }
+}

domain/src/security/JwtPayloadExtractor.kt

@@ -1,19 +0,0 @@
-package be.simplenotes.domain.security
-
-import be.simplenotes.types.LoggedInUser
-import com.auth0.jwt.exceptions.JWTVerificationException
-import javax.inject.Singleton
-
-@Singleton
-class JwtPayloadExtractor(private val jwt: SimpleJwt) {
-    operator fun invoke(token: String): LoggedInUser? = try {
-        val decodedJWT = jwt.verifier.verify(token)
-        val id = decodedJWT.getClaim(userIdField).asInt() ?: null
-        val username = decodedJWT.getClaim(usernameField).asString() ?: null
-        id?.let { username?.let { LoggedInUser(id, username) } }
-    } catch (e: JWTVerificationException) {
-        null
-    } catch (e: IllegalArgumentException) {
-        null
-    }
-}

domain/src/security/SimpleJwt.kt

@@ -1,28 +1,33 @@
 package be.simplenotes.domain.security
 
 import be.simplenotes.config.JwtConfig
-import be.simplenotes.types.LoggedInUser
 import com.auth0.jwt.JWT
 import com.auth0.jwt.JWTVerifier
 import com.auth0.jwt.algorithms.Algorithm
+import com.auth0.jwt.exceptions.JWTVerificationException
 import java.util.*
 import java.util.concurrent.TimeUnit
 import javax.inject.Singleton
 
-internal const val userIdField = "i"
-internal const val usernameField = "u"
-
 @Singleton
-class SimpleJwt(jwtConfig: JwtConfig) {
+class SimpleJwt<T>(jwtConfig: JwtConfig, private val mapper: JwtMapper<T>) {
     private val validityInMs = TimeUnit.MILLISECONDS.convert(jwtConfig.validity, jwtConfig.timeUnit)
     private val algorithm = Algorithm.HMAC256(jwtConfig.secret)
+    private val verifier: JWTVerifier = JWT.require(algorithm).build()
 
-    val verifier: JWTVerifier = JWT.require(algorithm).build()
-    fun sign(loggedInUser: LoggedInUser): String = JWT.create()
-        .withClaim(userIdField, loggedInUser.userId)
-        .withClaim(usernameField, loggedInUser.username)
+    fun sign(value: T): String = JWT.create()
+        .apply { mapper.build(this, value) }
         .withExpiresAt(getExpiration())
         .sign(algorithm)
 
+    fun extract(token: String): T? = try {
+        val decodedJWT = verifier.verify(token)
+        mapper.extract(decodedJWT)
+    } catch (e: JWTVerificationException) {
+        null
+    } catch (e: IllegalArgumentException) {
+        null
+    }
+
     private fun getExpiration() = Date(System.currentTimeMillis() + validityInMs)
 }

domain/src/usecases/users/login/LoginUseCaseImpl.kt

@@ -16,7 +16,7 @@ import javax.inject.Singleton
 internal class LoginUseCaseImpl(
     private val userRepository: UserRepository,
     private val passwordHash: PasswordHash,
-    private val jwt: SimpleJwt
+    private val jwt: SimpleJwt<LoggedInUser>
 ) : LoginUseCase {
     override fun login(form: LoginForm) = either.eager<LoginError, Token> {
         val user = !UserValidations.validateLogin(form)

domain/test/security/LoggedInUserExtractorTest.kt

@@ -16,14 +16,13 @@ import java.util.stream.Stream
 
 internal class LoggedInUserExtractorTest {
     private val jwtConfig = JwtConfig("a secret", 1, TimeUnit.HOURS)
-    private val simpleJwt = SimpleJwt(jwtConfig)
-    private val jwtPayloadExtractor = JwtPayloadExtractor(simpleJwt)
+    private val mapper = UserJwtMapper()
+    private val simpleJwt = SimpleJwt(jwtConfig, mapper)
 
     private fun createToken(username: String? = null, id: Int? = null, secret: String = jwtConfig.secret): Token {
         val algo = Algorithm.HMAC256(secret)
         return JWT.create().apply {
-            username?.let { withClaim(usernameField, it) }
-            id?.let { withClaim(userIdField, it) }
+            if (username != null && id != null) mapper.build(this, LoggedInUser(id, username))
         }.sign(algo)
     }
 
@@ -40,12 +39,12 @@ internal class LoggedInUserExtractorTest {
     @ParameterizedTest(name = "[{index}] token `{0}` should be invalid")
     @MethodSource("invalidTokens")
     fun `parse invalid tokens`(token: String) {
-        assertThat(jwtPayloadExtractor(token), absent())
+        assertThat(simpleJwt.extract(token), absent())
     }
 
     @Test
     fun `parse valid token`() {
         val token = createToken(username = "someone", id = 1)
-        assertThat(jwtPayloadExtractor(token), equalTo(LoggedInUser(1, "someone")))
+        assertThat(simpleJwt.extract(token), equalTo(LoggedInUser(1, "someone")))
     }
 }

domain/test/usecases/users/login/LoginUseCaseImplTest.kt

@@ -3,6 +3,7 @@ package be.simplenotes.domain.usecases.users.login
 import be.simplenotes.config.JwtConfig
 import be.simplenotes.domain.security.BcryptPasswordHash
 import be.simplenotes.domain.security.SimpleJwt
+import be.simplenotes.domain.security.UserJwtMapper
 import be.simplenotes.domain.testutils.isLeftOfType
 import be.simplenotes.domain.testutils.isRight
 import be.simplenotes.persistance.repositories.UserRepository
@@ -18,7 +19,7 @@ internal class LoginUseCaseImplTest {
     private val mockUserRepository = mockk<UserRepository>()
     private val passwordHash = BcryptPasswordHash(test = true)
     private val jwtConfig = JwtConfig("a secret", 1, TimeUnit.HOURS)
-    private val simpleJwt = SimpleJwt(jwtConfig)
+    private val simpleJwt = SimpleJwt(jwtConfig, UserJwtMapper())
     private val loginUseCase = LoginUseCaseImpl(mockUserRepository, passwordHash, simpleJwt)
 
     @BeforeEach