feat: support custom TimeProvider when validating tokens

* add verify function to OAuth2TokenProvider and use the TimeProvider if set - i.e. via overriding Nimbus DefaultJWTClaimsVerifier's currentTime function
* refactor tests for simplicity

build.gradle.kts

@@ -66,7 +66,7 @@ dependencies {
     implementation("com.fasterxml.jackson.module:jackson-module-kotlin:$jacksonVersion")
     implementation("org.freemarker:freemarker:$freemarkerVersion")
     implementation("org.bouncycastle:bcpkix-jdk18on:$bouncyCastleVersion")
-    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.3")
+    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.7.0")
     testImplementation("org.assertj:assertj-core:$assertjVersion")
     testImplementation("org.junit.jupiter:junit-jupiter-api:$junitJupiterVersion")
     testImplementation("org.junit.jupiter:junit-jupiter-params:$junitJupiterVersion")

src/main/kotlin/no/nav/security/mock/oauth2/introspect/Introspect.kt

@@ -3,15 +3,11 @@ package no.nav.security.mock.oauth2.introspect
 import com.fasterxml.jackson.annotation.JsonInclude
 import com.fasterxml.jackson.annotation.JsonProperty
 import com.nimbusds.jwt.JWTClaimsSet
-import com.nimbusds.jwt.SignedJWT
 import com.nimbusds.oauth2.sdk.OAuth2Error
-import com.nimbusds.oauth2.sdk.id.Issuer
 import mu.KotlinLogging
 import no.nav.security.mock.oauth2.OAuth2Exception
 import no.nav.security.mock.oauth2.extensions.OAuth2Endpoints.INTROSPECT
-import no.nav.security.mock.oauth2.extensions.issuerId
 import no.nav.security.mock.oauth2.extensions.toIssuerUrl
-import no.nav.security.mock.oauth2.extensions.verifySignatureAndIssuer
 import no.nav.security.mock.oauth2.http.OAuth2HttpRequest
 import no.nav.security.mock.oauth2.http.Route
 import no.nav.security.mock.oauth2.http.json
@@ -51,12 +47,10 @@ internal fun Route.Builder.introspect(tokenProvider: OAuth2TokenProvider) =
     }
 
 private fun OAuth2HttpRequest.verifyToken(tokenProvider: OAuth2TokenProvider): JWTClaimsSet? {
-    val tokenString = this.formParameters.get("token")
-    val issuer = url.toIssuerUrl()
-    val jwkSet = tokenProvider.publicJwkSet(issuer.issuerId())
-    val algorithm = tokenProvider.getAlgorithm()
     return try {
-        SignedJWT.parse(tokenString).verifySignatureAndIssuer(Issuer(issuer.toString()), jwkSet, algorithm)
+        this.formParameters.get("token")?.let {
+            tokenProvider.verify(url.toIssuerUrl(), it)
+        }
     } catch (e: Exception) {
         log.debug("token_introspection: failed signature validation")
         return null

src/main/kotlin/no/nav/security/mock/oauth2/token/KeyProvider.kt

@@ -3,9 +3,12 @@ package no.nav.security.mock.oauth2.token
 import com.nimbusds.jose.JWSAlgorithm
 import com.nimbusds.jose.jwk.ECKey
 import com.nimbusds.jose.jwk.JWK
+import com.nimbusds.jose.jwk.JWKSelector
 import com.nimbusds.jose.jwk.JWKSet
 import com.nimbusds.jose.jwk.KeyType
 import com.nimbusds.jose.jwk.RSAKey
+import com.nimbusds.jose.jwk.source.JWKSource
+import com.nimbusds.jose.proc.SecurityContext
 import no.nav.security.mock.oauth2.OAuth2Exception
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.LinkedBlockingDeque
@@ -15,7 +18,7 @@ open class KeyProvider
     constructor(
         private val initialKeys: List<JWK> = keysFromFile(INITIAL_KEYS_FILE),
         private val algorithm: String = JWSAlgorithm.RS256.name,
-    ) {
+    ) : JWKSource<SecurityContext> {
         private val signingKeys: ConcurrentHashMap<String, JWK> = ConcurrentHashMap()
 
         private var generator: KeyGenerator = KeyGenerator(JWSAlgorithm.parse(algorithm))
@@ -35,9 +38,11 @@ open class KeyProvider
                     KeyType.RSA.value -> {
                         RSAKey.Builder(polledJwk.toRSAKey()).keyID(keyId).build()
                     }
+
                     KeyType.EC.value -> {
                         ECKey.Builder(polledJwk.toECKey()).keyID(keyId).build()
                     }
+
                     else -> {
                         throw OAuth2Exception("Unsupported key type: ${polledJwk.keyType.value}")
                     }
@@ -63,4 +68,11 @@ open class KeyProvider
                 return emptyList()
             }
         }
+
+        override fun get(
+            jwkSelector: JWKSelector?,
+            context: SecurityContext?,
+        ): MutableList<JWK> {
+            return signingKeys.values.toMutableList()
+        }
     }

src/main/kotlin/no/nav/security/mock/oauth2/token/OAuth2TokenProvider.kt

@@ -7,8 +7,13 @@ import com.nimbusds.jose.crypto.ECDSASigner
 import com.nimbusds.jose.crypto.RSASSASigner
 import com.nimbusds.jose.jwk.JWKSet
 import com.nimbusds.jose.jwk.KeyType
+import com.nimbusds.jose.proc.DefaultJOSEObjectTypeVerifier
+import com.nimbusds.jose.proc.JWSVerificationKeySelector
+import com.nimbusds.jose.proc.SecurityContext
 import com.nimbusds.jwt.JWTClaimsSet
 import com.nimbusds.jwt.SignedJWT
+import com.nimbusds.jwt.proc.DefaultJWTClaimsVerifier
+import com.nimbusds.jwt.proc.DefaultJWTProcessor
 import com.nimbusds.oauth2.sdk.TokenRequest
 import no.nav.security.mock.oauth2.OAuth2Exception
 import no.nav.security.mock.oauth2.extensions.clientIdAsString
@@ -107,6 +112,13 @@ class OAuth2TokenProvider
                 builder.build()
             }.sign(issuerId, JOSEObjectType.JWT.type)
 
+        fun verify(
+            issuerUrl: HttpUrl,
+            token: String,
+        ): JWTClaimsSet {
+            return SignedJWT.parse(token).verify(issuerUrl)
+        }
+
         private fun JWTClaimsSet.sign(
             issuerId: String,
             type: String,
@@ -125,6 +137,7 @@ class OAuth2TokenProvider
                         sign(RSASSASigner(key.toRSAKey().toPrivateKey()))
                     }
                 }
+
                 supported && keyType == KeyType.EC.value -> {
                     SignedJWT(
                         jwsHeader(key.keyID, type, algorithm),
@@ -133,6 +146,7 @@ class OAuth2TokenProvider
                         sign(ECDSASigner(key.toECKey().toECPrivateKey()))
                     }
                 }
+
                 else -> {
                     throw OAuth2Exception("Unsupported algorithm: ${algorithm.name}")
                 }
@@ -177,4 +191,22 @@ class OAuth2TokenProvider
         }
 
         private fun Instant?.orNow(): Instant = this ?: Instant.now()
+
+        private fun SignedJWT.verify(issuerUrl: HttpUrl): JWTClaimsSet {
+            val jwtProcessor =
+                DefaultJWTProcessor<SecurityContext?>().apply {
+                    jwsTypeVerifier = DefaultJOSEObjectTypeVerifier(JOSEObjectType("JWT"))
+                    jwsKeySelector = JWSVerificationKeySelector(keyProvider.algorithm(), keyProvider)
+                    jwtClaimsSetVerifier =
+                        object : DefaultJWTClaimsVerifier<SecurityContext?>(
+                            JWTClaimsSet.Builder().issuer(issuerUrl.toString()).build(),
+                            HashSet(listOf("iat", "exp")),
+                        ) {
+                            override fun currentTime(): Date {
+                                return Date.from(timeProvider())
+                            }
+                        }
+                }
+            return jwtProcessor.process(this, null)
+        }
     }

src/main/kotlin/no/nav/security/mock/oauth2/userinfo/UserInfo.kt

@@ -1,16 +1,12 @@
 package no.nav.security.mock.oauth2.userinfo
 
 import com.nimbusds.jwt.JWTClaimsSet
-import com.nimbusds.jwt.SignedJWT
 import com.nimbusds.oauth2.sdk.ErrorObject
 import com.nimbusds.oauth2.sdk.http.HTTPResponse
-import com.nimbusds.oauth2.sdk.id.Issuer
 import mu.KotlinLogging
 import no.nav.security.mock.oauth2.OAuth2Exception
 import no.nav.security.mock.oauth2.extensions.OAuth2Endpoints.USER_INFO
-import no.nav.security.mock.oauth2.extensions.issuerId
 import no.nav.security.mock.oauth2.extensions.toIssuerUrl
-import no.nav.security.mock.oauth2.extensions.verifySignatureAndIssuer
 import no.nav.security.mock.oauth2.http.OAuth2HttpRequest
 import no.nav.security.mock.oauth2.http.Route
 import no.nav.security.mock.oauth2.http.json
@@ -27,12 +23,8 @@ internal fun Route.Builder.userInfo(tokenProvider: OAuth2TokenProvider) =
     }
 
 private fun OAuth2HttpRequest.verifyBearerToken(tokenProvider: OAuth2TokenProvider): JWTClaimsSet {
-    val tokenString = this.headers.bearerToken()
-    val issuer = url.toIssuerUrl()
-    val jwkSet = tokenProvider.publicJwkSet(issuer.issuerId())
-    val algorithm = tokenProvider.getAlgorithm()
     return try {
-        SignedJWT.parse(tokenString).verifySignatureAndIssuer(Issuer(issuer.toString()), jwkSet, algorithm)
+        tokenProvider.verify(url.toIssuerUrl(), this.headers.bearerToken())
     } catch (e: Exception) {
         throw invalidToken(e.message ?: "could not verify bearer token")
     }

src/test/kotlin/no/nav/security/mock/oauth2/introspect/IntrospectTest.kt

@@ -19,6 +19,8 @@ import no.nav.security.mock.oauth2.token.OAuth2TokenProvider
 import okhttp3.Headers
 import okhttp3.HttpUrl.Companion.toHttpUrl
 import org.junit.jupiter.api.Test
+import java.time.Instant
+import java.time.temporal.ChronoUnit
 
 internal class IntrospectTest {
     private val rs384TokenProvider = OAuth2TokenProvider(keyProvider = KeyProvider(initialKeys = emptyList(), algorithm = JWSAlgorithm.RS384.name))
@@ -66,6 +68,29 @@ internal class IntrospectTest {
         }
     }
 
+    @Test
+    fun `introspect should return active and claims from token when using a custom timeProvider in the OAuth2TokenProvider`() {
+        val issuerUrl = "http://localhost/default"
+        val yesterday = Instant.now().minus(1, ChronoUnit.DAYS)
+        val tokenProvider = OAuth2TokenProvider(timeProvider = { yesterday })
+        val claims =
+            mapOf(
+                "iss" to issuerUrl,
+                "client_id" to "yolo",
+                "token_type" to "token",
+                "sub" to "foo",
+            )
+        val token = tokenProvider.jwt(claims)
+        val request = request("$issuerUrl$INTROSPECT", token.serialize())
+
+        routes { introspect(tokenProvider) }.invoke(request).asClue {
+            it.status shouldBe 200
+            val response = it.parse<Map<String, Any>>()
+            response shouldContainAll claims
+            response shouldContain ("active" to true)
+        }
+    }
+
     @Test
     fun `introspect should return active false when token is missing`() {
         val url = "http://localhost/default$INTROSPECT"

src/test/kotlin/no/nav/security/mock/oauth2/token/OAuth2TokenProviderRSATest.kt

@@ -16,9 +16,7 @@ import okhttp3.HttpUrl.Companion.toHttpUrl
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.params.ParameterizedTest
 import org.junit.jupiter.params.provider.ValueSource
-import java.time.Clock
 import java.time.Instant
-import java.time.ZoneId
 import java.time.temporal.ChronoUnit
 import java.util.Date
 
@@ -104,86 +102,71 @@ internal class OAuth2TokenProviderRSATest {
         val yesterday = Instant.now().minus(1, ChronoUnit.DAYS)
         val tokenProvider = OAuth2TokenProvider(systemTime = yesterday)
 
-        tokenProvider.exchangeAccessToken(
-            tokenRequest =
-                nimbusTokenRequest(
-                    "id",
-                    "grant_type" to GrantType.CLIENT_CREDENTIALS.value,
-                    "scope" to "scope1",
-                ),
-            issuerUrl = "http://default_if_not_overridden".toHttpUrl(),
-            claimsSet = tokenProvider.jwt(mapOf()).jwtClaimsSet,
-            oAuth2TokenCallback = DefaultOAuth2TokenCallback(),
-        ).asClue {
+        tokenProvider.clientCredentialsToken("http://localhost/default").asClue {
             it.jwtClaimsSet.issueTime shouldBe Date.from(tokenProvider.systemTime)
-            println(it.serialize())
+        }
+
+        val now = Instant.now()
+        OAuth2TokenProvider().clientCredentialsToken("http://localhost/default").asClue {
+            it.jwtClaimsSet.issueTime shouldBeAfter now
         }
     }
 
     @Test
     fun `token should have issuedAt set dynamically according to timeProvider`() {
-        val clock =
-            object : Clock() {
-                private var clock = systemDefaultZone()
+        val timeProvider =
+            object : TimeProvider {
+                var time = Instant.now()
 
-                override fun instant() = clock.instant()
-
-                override fun withZone(zone: ZoneId) = clock.withZone(zone)
-
-                override fun getZone() = clock.zone
-
-                fun fixed(instant: Instant) {
-                    clock = fixed(instant, zone)
-                }
+                override fun invoke(): Instant = time
             }
 
-        val tokenProvider = OAuth2TokenProvider { clock.instant() }
+        val tokenProvider = OAuth2TokenProvider(timeProvider = timeProvider)
 
         val instant1 = Instant.parse("2000-12-03T10:15:30.00Z")
         val instant2 = Instant.parse("2020-01-21T00:00:00.00Z")
-        instant1 shouldNotBe instant2
-
-        run {
-            clock.fixed(instant1)
-            tokenProvider.systemTime shouldBe instant1
-
-            tokenProvider.exchangeAccessToken(
-                tokenRequest =
-                    nimbusTokenRequest(
-                        "id",
-                        "grant_type" to GrantType.CLIENT_CREDENTIALS.value,
-                        "scope" to "scope1",
-                    ),
-                issuerUrl = "http://default_if_not_overridden".toHttpUrl(),
-                claimsSet = tokenProvider.jwt(mapOf()).jwtClaimsSet,
-                oAuth2TokenCallback = DefaultOAuth2TokenCallback(),
-            )
-        }.asClue {
+
+        timeProvider.time = instant1
+        tokenProvider.systemTime shouldBe instant1
+
+        tokenProvider.clientCredentialsToken("http://localhost/default").asClue {
             it.jwtClaimsSet.issueTime shouldBe Date.from(instant1)
-            println(it.serialize())
         }
 
-        run {
-            clock.fixed(instant2)
-            tokenProvider.systemTime shouldBe instant2
-
-            tokenProvider.exchangeAccessToken(
-                tokenRequest =
-                    nimbusTokenRequest(
-                        "id",
-                        "grant_type" to GrantType.CLIENT_CREDENTIALS.value,
-                        "scope" to "scope1",
-                    ),
-                issuerUrl = "http://default_if_not_overridden".toHttpUrl(),
-                claimsSet = tokenProvider.jwt(mapOf()).jwtClaimsSet,
-                oAuth2TokenCallback = DefaultOAuth2TokenCallback(),
-            )
-        }.asClue {
+        timeProvider.time = instant2
+        tokenProvider.systemTime shouldBe instant2
+
+        tokenProvider.clientCredentialsToken("http://localhost/default").asClue {
             it.jwtClaimsSet.issueTime shouldBe Date.from(instant2)
-            println(it.serialize())
         }
     }
 
+    @Test
+    fun `token with issueTime set to yesterday should be able to validate with the verify function using the same timeprovider`() {
+        val yesterday = Instant.now().minus(1, ChronoUnit.DAYS)
+        val tokenProvider = OAuth2TokenProvider(timeProvider = { yesterday })
+
+        val token = tokenProvider.clientCredentialsToken("http://localhost/default")
+
+        token.jwtClaimsSet.issueTime shouldBe Date.from(tokenProvider.systemTime)
+
+        tokenProvider.verify("http://localhost/default".toHttpUrl(), token.serialize()).toJSONObject().asClue {
+            it shouldBe token.jwtClaimsSet.toJSONObject()
+        }
+    }
+
+    private fun OAuth2TokenProvider.clientCredentialsToken(issuerUrl: String): SignedJWT =
+        accessToken(
+            tokenRequest =
+                nimbusTokenRequest(
+                    "client1",
+                    "grant_type" to "client_credentials",
+                    "scope" to "scope1",
+                ),
+            issuerUrl = issuerUrl.toHttpUrl(),
+            oAuth2TokenCallback = DefaultOAuth2TokenCallback(),
+        )
+
     private fun idToken(issuerUrl: String): SignedJWT =
         tokenProvider.idToken(
             tokenRequest =
@@ -195,4 +178,6 @@ internal class OAuth2TokenProviderRSATest {
             issuerUrl = issuerUrl.toHttpUrl(),
             oAuth2TokenCallback = DefaultOAuth2TokenCallback(),
         )
+
+    private infix fun Date.shouldBeAfter(instant: Instant?) = this.after(Date.from(instant)) shouldBe true
 }