DevicePolicyManager: Add key generation functionality.
This is the crux of the Verified Access feature implementation:
Adding the ability to generate KeyChain keys directly by the
secure hardware, rather than installing software-generated keys
into KeyChain.
Add generateKeyPair to the DevicePolicyManager, which delegates key
generation (via the DevicePolicyManagerService) to the KeyChainService.
Design highlights:
* The key generation is delegated via the DevicePolicyManagerService to
check that only authorized callers request key generation in KeyChain.
* KeyChainService performs the actual key generation so it owns the key
in Keystore outright.
* DevicePolicyManagerService then grants the calling app access to the
Keystore key, so it can actually be used.
* Loading the public/private key pair, as well as attestation
certificate chain, is done in the client code (DevicePolicyManager)
to save parceling / unparceling those objects across process
boundaries twice (for no good reason).
NOTE: The key attestation functionality (that includes Device ID) is
missing/untested. Will be added in a follow-up CL as this one is quite
big already.
HIGHLIGHT FOR REVIEWERS:
* API: New API in DevicePolicyManager.
Bug: 63388672
Test: cts-tradefed run commandAndExit cts-dev -a armeabi-v7a -m CtsDevicePolicyManagerTestCases -t com.android.cts.devicepolicy.DeviceOwnerTest#testKeyManagement -l DEBUG; adb shell am instrument 'android.security.tests/android.support.test.runner.AndroidJUnitRunner' (After building the KeystoreTests target and installing the apk)
Change-Id: I73762c9123f32a94d454ba4f8b533883b55c44cc
diff --git a/keystore/java/android/security/AttestedKeyPair.java b/keystore/java/android/security/AttestedKeyPair.java
new file mode 100644
index 0000000..c6bff5c
--- /dev/null
+++ b/keystore/java/android/security/AttestedKeyPair.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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 android.security;
+
+import java.security.KeyPair;
+import java.security.cert.Certificate;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * The {@code AttestedKeyPair} class contains a {@code KeyPair} instance of
+ * keys generated by Keystore and owned by KeyChain, as well as an attestation
+ * record for the key.
+ *
+ * <p>Such keys can be obtained by calling
+ * {@link android.app.admin.DevicePolicyManager#generateKeyPair}.
+ */
+
+public final class AttestedKeyPair {
+ private final KeyPair mKeyPair;
+ private final Certificate[] mAttestationRecord;
+
+ /**
+ * @hide Only created by the platform, no need to expose as public API.
+ */
+ public AttestedKeyPair(KeyPair keyPair, Certificate[] attestationRecord) {
+ mKeyPair = keyPair;
+ mAttestationRecord = attestationRecord;
+ }
+
+ /**
+ * Returns the generated key pair associated with the attestation record
+ * in this instance.
+ */
+ public KeyPair getKeyPair() {
+ return mKeyPair;
+ }
+
+ /**
+ * Returns the attestation record for the key pair in this instance.
+ *
+ * The attestation record is a chain of certificates. The leaf certificate links to the public
+ * key of this key pair and other properties of the key or the device. If the key is in secure
+ * hardware, and if the secure hardware supports attestation, the leaf certificate will be
+ * signed by a chain of certificates rooted at a trustworthy CA key. Otherwise the chain will be
+ * rooted at an untrusted certificate.
+ *
+ * The attestation record could be for properties of the key, or include device identifiers.
+ *
+ * See {@link android.security.keystore.KeyGenParameterSpec.Builder#setAttestationChallenge}
+ * and <a href="https://developer.android.com/training/articles/security-key-attestation.html">
+ * Key Attestation</a> for the format of the attestation record inside the certificate.
+ */
+ public List<Certificate> getAttestationRecord() {
+ if (mAttestationRecord == null) {
+ return new ArrayList();
+ }
+ return Arrays.asList(mAttestationRecord);
+ }
+}