content: /*
   * Copyright (C) 2018 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.content.pm;
  
  
  import android.annotation.NonNull;
  import android.os.Parcel;
  import android.os.Parcelable;
  
  /**
   * Information pertaining to the signing certificates used to sign a package.
   */
  public final class SigningInfo implements Parcelable {
  
      @NonNull
      private final PackageParser.SigningDetails mSigningDetails;
  
      public SigningInfo() {
          mSigningDetails = PackageParser.SigningDetails.UNKNOWN;
      }
  
      /**
       * @hide only packagemanager should be populating this
       */
      public SigningInfo(PackageParser.SigningDetails signingDetails) {
          mSigningDetails = new PackageParser.SigningDetails(signingDetails);
      }
  
      public SigningInfo(SigningInfo orig) {
          mSigningDetails = new PackageParser.SigningDetails(orig.mSigningDetails);
      }
  
      private SigningInfo(Parcel source) {
          mSigningDetails = PackageParser.SigningDetails.CREATOR.createFromParcel(source);
      }
  
      /**
       * Although relatively uncommon, packages may be signed by more than one signer, in which case
       * their identity is viewed as being the set of all signers, not just any one.
       */
      public boolean hasMultipleSigners() {
          return mSigningDetails.signatures != null && mSigningDetails.signatures.length > 1;
      }
  
      /**
       * APK Signature Scheme v3 enables packages to provide a proof-of-rotation record that the
       * platform verifies, and uses, to allow the use of new signing certificates.  This is only
       * available to packages that are not signed by multiple signers.  In the event of a change to a
       * new signing certificate, the package's past signing certificates are presented as well.  Any
       * check of a package's signing certificate should also include a search through its entire
       * signing history, since it could change to a new signing certificate at any time.
       */
      public boolean hasPastSigningCertificates() {
          return mSigningDetails.signatures != null
                  && mSigningDetails.pastSigningCertificates != null;
      }
  
      /**
       * Returns the signing certificates this package has proven it is authorized to use. This
       * includes both the signing certificate associated with the signer of the package and the past
       * signing certificates it included as its proof of signing certificate rotation.  This method
       * is the preferred replacement for the {@code GET_SIGNATURES} flag used with {@link
       * PackageManager#getPackageInfo(String, int)}.  When determining if a package is signed by a
       * desired certificate, the returned array should be checked to determine if it is one of the
       * entries.
       *
       * <note>
       *     This method returns null if the package is signed by multiple signing certificates, as
       *     opposed to being signed by one current signer and also providing the history of past
       *     signing certificates.  {@link #hasMultipleSigners()} may be used to determine if this
       *     package is signed by multiple signers.  Packages which are signed by multiple signers
       *     cannot change their signing certificates and their {@code Signature} array should be
       *     checked to make sure that every entry matches the looked-for signing certificates.
       * </note>
       */
      public Signature[] getSigningCertificateHistory() {
          if (hasMultipleSigners()) {
              return null;
          } else if (!hasPastSigningCertificates()) {
  
              // this package is only signed by one signer with no history, return it
              return mSigningDetails.signatures;
          } else {
  
              // this package has provided proof of past signing certificates, include them
              return mSigningDetails.pastSigningCertificates;
          }
      }
  
      /**
       * Returns the signing certificates used to sign the APK contents of this application.  Not
       * including any past signing certificates the package proved it is authorized to use.
       * <note>
       *     This method should not be used unless {@link #hasMultipleSigners()} returns true,
       *     indicating that {@link #getSigningCertificateHistory()} cannot be used, otherwise {@link
       *     #getSigningCertificateHistory()} should be preferred.
       * </note>
       */
      public Signature[] getApkContentsSigners() {
          return mSigningDetails.signatures;
      }
  
      @Override
      public int describeContents() {
          return 0;
      }
  
      @Override
      public void writeToParcel(Parcel dest, int parcelableFlags) {
          mSigningDetails.writeToParcel(dest, parcelableFlags);
      }
  
      public static final @android.annotation.NonNull Parcelable.Creator<SigningInfo> CREATOR =
              new Parcelable.Creator<SigningInfo>() {
          @Override
          public SigningInfo createFromParcel(Parcel source) {
              return new SigningInfo(source);
          }
  
          @Override
          public SigningInfo[] newArray(int size) {
              return new SigningInfo[size];
          }
      };
  }
  