src/main/java/com/android/tools/build/apkzlib/zfile/ZFiles.java

/*
 * Copyright (C) 2016 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 com.android.tools.build.apkzlib.zfile;

import com.android.tools.build.apkzlib.sign.ManifestGenerationExtension;
import com.android.tools.build.apkzlib.sign.SigningExtension;
import com.android.tools.build.apkzlib.zip.AlignmentRule;
import com.android.tools.build.apkzlib.zip.AlignmentRules;
import com.android.tools.build.apkzlib.zip.ZFile;
import com.android.tools.build.apkzlib.zip.ZFileOptions;
import java.io.File;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.cert.X509Certificate;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;

/**
 * Factory for {@link ZFile}s that are specifically configured to be APKs, AARs, ...
 */
public class ZFiles {

    /**
     * By default all non-compressed files are alignment at 4 byte boundaries..
     */
    private static final AlignmentRule APK_DEFAULT_RULE = AlignmentRules.constant(4);

    /**
     * Default build by string.
     */
    private static final String DEFAULT_BUILD_BY = "Generated-by-ADT";

    /**
     * Default created by string.
     */
    private static final String DEFAULT_CREATED_BY = "Generated-by-ADT";

    /**
     * Creates a new zip file configured as an apk, based on a given file.
     *
     * @param f the file, if this path does not represent an existing path, will create a
     * {@link ZFile} based on an non-existing path (a zip will be created when
     * {@link ZFile#close()} is invoked)
     * @param options the options to create the {@link ZFile}
     * @return the zip file
     * @throws IOException failed to create the zip file
     */
    @Nonnull
    public static ZFile apk(@Nonnull File f, @Nonnull ZFileOptions options) throws IOException {
        options.setAlignmentRule(
                AlignmentRules.compose(options.getAlignmentRule(), APK_DEFAULT_RULE));
        return new ZFile(f, options);
    }

    /**
     * Creates a new zip file configured as an apk, based on a given file.
     *
     * @param f the file, if this path does not represent an existing path, will create a
     * {@link ZFile} based on an non-existing path (a zip will be created when
     * {@link ZFile#close()} is invoked)
     * @param options the options to create the {@link ZFile}
     * @param key the {@link PrivateKey} used to sign the archive, or {@code null}.
     * @param certificate the {@link X509Certificate} used to sign the archive, or
     * {@code null}.
     * @param v1SigningEnabled whether signing with JAR Signature Scheme (aka v1 signing) is
     *        enabled.
     * @param v2SigningEnabled whether signing with APK Signature Scheme v2 (aka v2 signing) is
     *        enabled.
     * @param builtBy who to mark as builder in the manifest
     * @param createdBy who to mark as creator in the manifest
     * @param minSdkVersion minimum SDK version supported
     * @return the zip file
     * @throws IOException failed to create the zip file
     */
    @Nonnull
    public static ZFile apk(
            @Nonnull File f,
            @Nonnull ZFileOptions options,
            @Nullable PrivateKey key,
            @Nullable X509Certificate certificate,
            boolean v1SigningEnabled,
            boolean v2SigningEnabled,
            @Nullable String builtBy,
            @Nullable String createdBy,
            int minSdkVersion)
            throws IOException {
        ZFile zfile = apk(f, options);

        if (builtBy == null) {
            builtBy = DEFAULT_BUILD_BY;
        }

        if (createdBy == null) {
            createdBy = DEFAULT_CREATED_BY;
        }

        ManifestGenerationExtension manifestExt = new ManifestGenerationExtension(builtBy,
                createdBy);
        manifestExt.register(zfile);

        if (key != null && certificate != null) {
            try {
                new SigningExtension(
                        minSdkVersion,
                        certificate,
                        key,
                        v1SigningEnabled,
                        v2SigningEnabled).register(zfile);
            } catch (NoSuchAlgorithmException | InvalidKeyException e) {
                throw new IOException("Failed to create signature extensions", e);
            }
        }

        return zfile;
    }
}