| /* Copyright 2019, The Android Open Source Project, Inc. |
| * |
| * 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.google.android.attestation; |
| |
| import static com.google.android.attestation.Constants.ATTESTATION_APPLICATION_ID_PACKAGE_INFOS_INDEX; |
| import static com.google.android.attestation.Constants.ATTESTATION_APPLICATION_ID_SIGNATURE_DIGESTS_INDEX; |
| import static com.google.android.attestation.Constants.ATTESTATION_PACKAGE_INFO_PACKAGE_NAME_INDEX; |
| import static com.google.android.attestation.Constants.ATTESTATION_PACKAGE_INFO_VERSION_INDEX; |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Objects; |
| import org.bouncycastle.asn1.ASN1Encodable; |
| import org.bouncycastle.asn1.ASN1Integer; |
| import org.bouncycastle.asn1.ASN1OctetString; |
| import org.bouncycastle.asn1.ASN1Sequence; |
| import org.bouncycastle.asn1.ASN1Set; |
| import org.bouncycastle.asn1.DEROctetString; |
| |
| /** |
| * This data structure reflects the Android platform's belief as to which apps are allowed to use |
| * the secret key material under attestation. The ID can comprise multiple packages if and only if |
| * multiple packages share the same UID. |
| */ |
| public class AttestationApplicationId implements Comparable<AttestationApplicationId> { |
| public final List<AttestationPackageInfo> packageInfos; |
| public final List<byte[]> signatureDigests; |
| |
| private AttestationApplicationId(DEROctetString attestationApplicationId) throws IOException { |
| ASN1Sequence attestationApplicationIdSequence = |
| (ASN1Sequence) ASN1Sequence.fromByteArray(attestationApplicationId.getOctets()); |
| ASN1Set attestationPackageInfos = |
| (ASN1Set) |
| attestationApplicationIdSequence.getObjectAt( |
| ATTESTATION_APPLICATION_ID_PACKAGE_INFOS_INDEX); |
| this.packageInfos = new ArrayList<>(); |
| for (ASN1Encodable packageInfo : attestationPackageInfos) { |
| this.packageInfos.add(new AttestationPackageInfo((ASN1Sequence) packageInfo)); |
| } |
| |
| ASN1Set digests = |
| (ASN1Set) |
| attestationApplicationIdSequence.getObjectAt( |
| ATTESTATION_APPLICATION_ID_SIGNATURE_DIGESTS_INDEX); |
| this.signatureDigests = new ArrayList<>(); |
| for (ASN1Encodable digest : digests) { |
| this.signatureDigests.add(((ASN1OctetString) digest).getOctets()); |
| } |
| } |
| |
| AttestationApplicationId( |
| List<AttestationPackageInfo> packageInfos, List<byte[]> signatureDigests) { |
| this.packageInfos = packageInfos; |
| this.signatureDigests = signatureDigests; |
| } |
| |
| static AttestationApplicationId createAttestationApplicationId( |
| DEROctetString attestationApplicationId) { |
| if (attestationApplicationId == null) { |
| return null; |
| } |
| try { |
| return new AttestationApplicationId(attestationApplicationId); |
| } catch (IOException e) { |
| return null; |
| } |
| } |
| |
| @Override |
| public int compareTo(AttestationApplicationId other) { |
| int res = Integer.compare(packageInfos.size(), other.packageInfos.size()); |
| if (res != 0) { |
| return res; |
| } |
| for (int i = 0; i < packageInfos.size(); ++i) { |
| res = packageInfos.get(i).compareTo(other.packageInfos.get(i)); |
| if (res != 0) { |
| return res; |
| } |
| } |
| res = Integer.compare(signatureDigests.size(), other.signatureDigests.size()); |
| if (res != 0) { |
| return res; |
| } |
| ByteArrayComparator cmp = new ByteArrayComparator(); |
| for (int i = 0; i < signatureDigests.size(); ++i) { |
| res = cmp.compare(signatureDigests.get(i), other.signatureDigests.get(i)); |
| if (res != 0) { |
| return res; |
| } |
| } |
| return res; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| return (o instanceof AttestationApplicationId) |
| && (compareTo((AttestationApplicationId) o) == 0); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(packageInfos, Arrays.deepHashCode(signatureDigests.toArray())); |
| } |
| |
| /** Provides package's name and version number. */ |
| public static class AttestationPackageInfo implements Comparable<AttestationPackageInfo> { |
| public final String packageName; |
| public final long version; |
| |
| private AttestationPackageInfo(ASN1Sequence packageInfo) { |
| this.packageName = |
| new String( |
| ((ASN1OctetString) |
| packageInfo.getObjectAt(ATTESTATION_PACKAGE_INFO_PACKAGE_NAME_INDEX)) |
| .getOctets(), |
| UTF_8); |
| this.version = |
| ((ASN1Integer) packageInfo.getObjectAt(ATTESTATION_PACKAGE_INFO_VERSION_INDEX)) |
| .getValue() |
| .longValue(); |
| } |
| |
| AttestationPackageInfo(String packageName, long version) { |
| this.packageName = packageName; |
| this.version = version; |
| } |
| |
| @Override |
| public int compareTo(AttestationPackageInfo other) { |
| int res = packageName.compareTo(other.packageName); |
| if (res != 0) { |
| return res; |
| } |
| res = Long.compare(version, other.version); |
| if (res != 0) { |
| return res; |
| } |
| return res; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| return (o instanceof AttestationPackageInfo) && (compareTo((AttestationPackageInfo) o) == 0); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(packageName, version); |
| } |
| } |
| |
| private static class ByteArrayComparator implements java.util.Comparator<byte[]> { |
| @Override |
| public int compare(byte[] a, byte[] b) { |
| int res = Integer.compare(a.length, b.length); |
| if (res != 0) { |
| return res; |
| } |
| for (int i = 0; i < a.length; ++i) { |
| res = Byte.compare(a[i], b[i]); |
| if (res != 0) { |
| return res; |
| } |
| } |
| return res; |
| } |
| } |
| } |