Eran Messeri 852c8f121f 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
2017-12-07 15:12:30 +00:00

76 lines
2.7 KiB
Java

/*
* 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);
}
}