feat: Renew expiring endpoint certificates

lib/src/main/java/tech/relaycorp/awaladroid/Awala.kt

@@ -9,7 +9,9 @@ import tech.relaycorp.awala.keystores.file.FileKeystoreRoot
 import tech.relaycorp.awala.keystores.file.FileSessionPublicKeystore
 import tech.relaycorp.awaladroid.background.ServiceInteractor
 import tech.relaycorp.awaladroid.endpoint.ChannelManager
+import tech.relaycorp.awaladroid.endpoint.FirstPartyEndpoint
 import tech.relaycorp.awaladroid.endpoint.HandleGatewayCertificateChange
+import tech.relaycorp.awaladroid.endpoint.RenewExpiringCertificates
 import tech.relaycorp.awaladroid.storage.StorageImpl
 import tech.relaycorp.awaladroid.storage.persistence.DiskPersistence
 import tech.relaycorp.relaynet.nodes.EndpointManager
@@ -53,7 +55,10 @@ public object Awala {
         )
 
         coroutineScope {
-            launch { fileCertificateStore.deleteExpired() }
+            launch {
+                RenewExpiringCertificates(androidPrivateKeyStore, FirstPartyEndpoint::load)()
+                fileCertificateStore.deleteExpired()
+            }
         }
     }
 

lib/src/main/java/tech/relaycorp/awaladroid/endpoint/RenewExpiringCertificates.kt

@@ -0,0 +1,31 @@
+package tech.relaycorp.awaladroid.endpoint
+
+import java.time.ZonedDateTime
+import kotlin.time.Duration
+import kotlin.time.days
+import tech.relaycorp.relaynet.keystores.PrivateKeyStore
+import tech.relaycorp.relaynet.wrappers.privateAddress
+import tech.relaycorp.relaynet.wrappers.x509.Certificate
+
+internal class RenewExpiringCertificates(
+    private val privateKeyStore: PrivateKeyStore,
+    private val firstPartyEndpointLoader: suspend (String) -> FirstPartyEndpoint?
+) {
+
+    suspend operator fun invoke() {
+        privateKeyStore.retrieveAllIdentityKeys()
+            .mapNotNull { firstPartyEndpointLoader(it.privateAddress) }
+            .forEach {
+                if (it.identityCertificate.isExpiring) {
+                    it.reRegister()
+                }
+            }
+    }
+
+    private val Certificate.isExpiring get() =
+        expiryDate <= ZonedDateTime.now().plusSeconds(EXPIRATION_THRESHOLD.inWholeSeconds)
+
+    companion object {
+        internal val EXPIRATION_THRESHOLD = Duration.days(60)
+    }
+}

lib/src/test/java/tech/relaycorp/awaladroid/endpoint/RenewExpiringCertificatesTest.kt

@@ -0,0 +1,55 @@
+package tech.relaycorp.awaladroid.endpoint
+
+import com.nhaarman.mockitokotlin2.mock
+import com.nhaarman.mockitokotlin2.never
+import com.nhaarman.mockitokotlin2.verify
+import com.nhaarman.mockitokotlin2.whenever
+import java.time.ZonedDateTime
+import kotlinx.coroutines.test.runBlockingTest
+import org.junit.Before
+import org.junit.Test
+import tech.relaycorp.relaynet.issueEndpointCertificate
+import tech.relaycorp.relaynet.keystores.PrivateKeyStore
+import tech.relaycorp.relaynet.testing.pki.KeyPairSet
+
+internal class RenewExpiringCertificatesTest() {
+
+    private val privateKeyStore = mock<PrivateKeyStore>()
+
+    @Before
+    fun setUp() = runBlockingTest {
+        whenever(privateKeyStore.retrieveAllIdentityKeys())
+            .thenReturn(listOf(KeyPairSet.PRIVATE_ENDPOINT.private))
+    }
+
+    @Test
+    fun `renews expiring certificates`() = runBlockingTest {
+        val expiringEndpoint = buildFirstPartyEndpoint(ZonedDateTime.now().plusDays(50))
+        val subject = RenewExpiringCertificates(privateKeyStore) { expiringEndpoint }
+
+        subject()
+
+        verify(expiringEndpoint).reRegister()
+    }
+
+    @Test
+    fun `does not renew not expiring certificates`() = runBlockingTest {
+        val notExpiringEndpoint = buildFirstPartyEndpoint(ZonedDateTime.now().plusDays(70))
+        val subject = RenewExpiringCertificates(privateKeyStore) { notExpiringEndpoint }
+
+        subject()
+
+        verify(notExpiringEndpoint, never()).reRegister()
+    }
+
+    private fun buildFirstPartyEndpoint(certExpiryDate: ZonedDateTime): FirstPartyEndpoint {
+        val firstPartyEndpoint = mock<FirstPartyEndpoint>()
+        val expiringCert = issueEndpointCertificate(
+            KeyPairSet.PRIVATE_ENDPOINT.public,
+            KeyPairSet.PRIVATE_GW.private,
+            certExpiryDate
+        )
+        whenever(firstPartyEndpoint.identityCertificate).thenReturn(expiringCert)
+        return firstPartyEndpoint
+    }
+}