Add JvmName for GoogleRevocationList to allow Java users

src/main/kotlin/GoogleRevocationList.kt

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@file:JvmName("GoogleRevocationList")
+
+package com.android.keyattestation.verifier
+
+import com.google.gson.Gson
+import java.io.IOException
+import java.io.InputStream
+import java.io.InputStreamReader
+import java.net.HttpURLConnection
+import java.net.URI
+import java.net.URL
+
+/**
+ * Fetches Google's revocation status list from the web.
+ *
+ * This function will fail-closed if it cannot download or parse the revocation list, by throwing an
+ * exception.
+ *
+ * @return A set of revoked serial numbers.
+ */
+fun getGoogleRevocationStatusFromWeb(): Set<String> =
+  getRevocationStatusFromWeb(
+    URI.create("https://android.googleapis.com/attestation/status").toURL()
+  )
+
+/**
+ * Fetches a revocation status list from the web.
+ *
+ * This function will fail-closed if it cannot download or parse the revocation list, by throwing an
+ * exception.
+ *
+ * @return A set of revoked serial numbers.
+ */
+fun getRevocationStatusFromWeb(
+  url: URL,
+  connectionProvider: (URL) -> HttpURLConnection = {
+    (it.openConnection() as? HttpURLConnection)
+      ?: throw IllegalArgumentException("Could not open HttpURLConnection to $it")
+  },
+): Set<String> {
+  val connection = connectionProvider(url)
+  try {
+    connection.requestMethod = "GET"
+    connection.connect()
+
+    if (connection.responseCode != HttpURLConnection.HTTP_OK) {
+      throw IOException(
+        "Failed to fetch revocation list from $url: HTTP ${connection.responseCode}"
+      )
+    }
+    return parseAttestationStatus(connection.inputStream)
+  } finally {
+    connection.disconnect()
+  }
+}
+
+/**
+ * Parses a revocation status list from an input stream.
+ *
+ * This function will fail-closed if it cannot parse the revocation list, by throwing an exception.
+ *
+ * @return A set of revoked serial numbers.
+ */
+fun parseAttestationStatus(input: InputStream): Set<String> {
+  data class StatusEntry(val status: String)
+  data class StatusFile(val entries: Map<String, StatusEntry>)
+
+  return Gson()
+    .fromJson(InputStreamReader(input), StatusFile::class.java)
+    .entries
+    .filterValues { it.status == "REVOKED" }
+    .keys
+}

src/test/kotlin/GoogleRevocationListTest.kt

@@ -0,0 +1,152 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.keyattestation.verifier
+
+import com.google.common.truth.Truth.assertThat
+import java.io.IOException
+import java.io.InputStream
+import java.net.HttpURLConnection
+import java.net.URI
+import java.net.URL
+import kotlin.test.assertFailsWith
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+@RunWith(JUnit4::class)
+class GoogleRevocationListTest {
+  @Test
+  fun getGoogleRevocationStatusFromWeb_success() {
+    val json =
+      """
+      {
+        "entries": {
+          "abc": { "status": "REVOKED" },
+          "def": { "status": "OK" }
+        }
+      }
+      """
+        .trimIndent()
+    val uri = URI("http://localhost")
+    val result =
+      getRevocationStatusFromWeb(uri.toURL()) {
+        FakeHttpURLConnection(uri.toURL(), HttpURLConnection.HTTP_OK, json)
+      }
+
+    assertThat(result).containsExactly("abc")
+  }
+
+  @Test
+  fun getRevocationStatusFromWeb_httpError_throwsIOException() {
+    val uri = URI("http://localhost")
+    assertFailsWith<IOException> {
+      getRevocationStatusFromWeb(uri.toURL()) {
+        FakeHttpURLConnection(uri.toURL(), HttpURLConnection.HTTP_NOT_FOUND)
+      }
+    }
+  }
+
+  @Test
+  fun parseAttestationStatus_emptyList() {
+    val json = """{"entries": {}}"""
+    val result = parseAttestationStatus(json.byteInputStream())
+    assertThat(result).isEmpty()
+  }
+
+  @Test
+  fun parseAttestationStatus_revokedAndOkEntries() {
+    val json =
+      """
+      {
+        "entries": {
+          "abc": {
+            "status": "REVOKED",
+            "reason": "KEY_COMPROMISE"
+          },
+          "def": {
+            "status": "OK"
+          },
+          "123": {
+            "status": "REVOKED",
+            "reason": "SUPERSEDED"
+          }
+        }
+      }
+      """
+        .trimIndent()
+    val result = parseAttestationStatus(json.byteInputStream())
+    assertThat(result).containsExactly("abc", "123")
+  }
+
+  @Test
+  fun parseAttestationStatus_onlyOkEntries() {
+    val json =
+      """
+      {
+        "entries": {
+          "def": {
+            "status": "OK"
+          },
+          "456": {
+            "status": "OK"
+          }
+        }
+      }
+      """
+        .trimIndent()
+    val result = parseAttestationStatus(json.byteInputStream())
+    assertThat(result).isEmpty()
+  }
+
+  @Test
+  fun parseAttestationStatus_onlyRevokedEntries() {
+    val json =
+      """
+      {
+        "entries": {
+          "abc": {
+            "status": "REVOKED",
+            "reason": "KEY_COMPROMISE"
+          },
+          "123": {
+            "status": "REVOKED",
+            "reason": "SUPERSEDED"
+          }
+        }
+      }
+      """
+        .trimIndent()
+    val result = parseAttestationStatus(json.byteInputStream())
+    assertThat(result).containsExactly("abc", "123")
+  }
+}
+
+private class FakeHttpURLConnection(
+  url: URL,
+  private val fakeResponseCode: Int,
+  val responseBody: String = "",
+) : HttpURLConnection(url) {
+  override fun connect() {}
+
+  override fun disconnect() {}
+
+  override fun getInputStream(): InputStream = responseBody.byteInputStream()
+
+  override fun getResponseCode() = fakeResponseCode
+
+  override fun usingProxy() = false
+}