Jwt converters (#48)

* JWT converter

* Use interface instead of callback to have more control

Author: adhesivee

oauth2-server-jwt/pom.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>kotlin-oauth2-server</artifactId>
+        <groupId>nl.myndocs</groupId>
+        <version>0.3.2-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>oauth2-server-jwt</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>nl.myndocs</groupId>
+            <artifactId>oauth2-server-core</artifactId>
+            <version>${project.version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.auth0</groupId>
+            <artifactId>java-jwt</artifactId>
+            <version>3.5.0</version>
+        </dependency>
+    </dependencies>
+</project>

oauth2-server-jwt/src/main/java/nl/myndocs/convert/DefaultJwtBuilder.kt

@@ -0,0 +1,20 @@
+package nl.myndocs.convert
+
+import com.auth0.jwt.JWT
+import java.time.Instant
+import java.util.*
+
+object DefaultJwtBuilder : JwtBuilder {
+    override fun buildJwt(username: String?, clientId: String, requestedScopes: Set<String>, expiresInSeconds: Long) =
+            JWT.create()
+                    .withIssuedAt(Date.from(Instant.now()))
+                    .withExpiresAt(
+                            Date.from(
+                                    Instant.now()
+                                            .plusSeconds(expiresInSeconds)
+                            )
+                    )
+                    .withClaim("client_id", clientId)
+                    .withArrayClaim("scopes", requestedScopes.toTypedArray())
+                    .let { withBuilder -> if (username != null) withBuilder.withClaim("username", username) else withBuilder }
+}

oauth2-server-jwt/src/main/java/nl/myndocs/convert/JwtAccessTokenConverter.kt

@@ -0,0 +1,32 @@
+package nl.myndocs.convert
+
+import com.auth0.jwt.algorithms.Algorithm
+import nl.myndocs.oauth2.token.AccessToken
+import nl.myndocs.oauth2.token.RefreshToken
+import nl.myndocs.oauth2.token.converter.AccessTokenConverter
+import java.time.Instant
+
+class JwtAccessTokenConverter(
+        private val algorithm: Algorithm,
+        private val accessTokenExpireInSeconds: Int = 3600,
+        private val jwtBuilder: JwtBuilder = DefaultJwtBuilder
+) : AccessTokenConverter {
+    override fun convertToToken(username: String?, clientId: String, requestedScopes: Set<String>, refreshToken: RefreshToken?): AccessToken {
+        val jwtBuilder = jwtBuilder.buildJwt(
+                username,
+                clientId,
+                requestedScopes,
+                accessTokenExpireInSeconds.toLong()
+        )
+
+        return AccessToken(
+                jwtBuilder.sign(algorithm),
+                "bearer",
+                Instant.now().plusSeconds(accessTokenExpireInSeconds.toLong()),
+                username,
+                clientId,
+                requestedScopes,
+                refreshToken
+        )
+    }
+}

oauth2-server-jwt/src/main/java/nl/myndocs/convert/JwtBuilder.kt

@@ -0,0 +1,7 @@
+package nl.myndocs.convert
+
+import com.auth0.jwt.JWTCreator
+
+interface JwtBuilder {
+    fun buildJwt(username: String?, clientId: String, requestedScopes: Set<String>, expiresInSeconds: Long): JWTCreator.Builder
+}

oauth2-server-jwt/src/main/java/nl/myndocs/convert/JwtRefreshTokenConverter.kt

@@ -0,0 +1,29 @@
+package nl.myndocs.convert
+
+import com.auth0.jwt.algorithms.Algorithm
+import nl.myndocs.oauth2.token.RefreshToken
+import nl.myndocs.oauth2.token.converter.RefreshTokenConverter
+import java.time.Instant
+
+class JwtRefreshTokenConverter(
+        private val algorithm: Algorithm,
+        private val refreshTokenExpireInSeconds: Int = 86400,
+        private val jwtBuilder: JwtBuilder = DefaultJwtBuilder
+) : RefreshTokenConverter {
+    override fun convertToToken(username: String?, clientId: String, requestedScopes: Set<String>): RefreshToken {
+        val jwtBuilder = jwtBuilder.buildJwt(
+                username,
+                clientId,
+                requestedScopes,
+                refreshTokenExpireInSeconds.toLong()
+        )
+
+        return RefreshToken(
+                jwtBuilder.sign(algorithm),
+                Instant.now().plusSeconds(refreshTokenExpireInSeconds.toLong()),
+                username,
+                clientId,
+                requestedScopes
+        )
+    }
+}

pom.xml

@@ -25,6 +25,7 @@
         <module>oauth2-server-javalin</module>
         <module>oauth2-server-sparkjava</module>
         <module>oauth2-server-http4k</module>
+        <module>oauth2-server-jwt</module>
     </modules>
 
     <dependencies>