我正在尝试为设备构建自定义Android(基于AOSP 7.1)。我想获得通过USB进行侧载的应用程序的签名。应用程序尚未安装在系统上。我最终的目标是比较APK与平台签名的签名,如下所示:https://gist.github.com/scottyab/b849701972d57cf9562e
我找到了许多指南,包括这一个 - How to get APK signing signature?
并按照盛峰李对接受的答案的评论 - “你需要将未安装的apk推送到你可以获得apk的位置,如SD_CARD,然后使用context.getPackageManager().getPackageAchiveInfo(NOT_INSTALL_APK_PATH,PackageManager.GET_SIGNATURES) .signatures[0]
获取其hashCode。并比较它们”
我正在修改AOSP(https://github.com/aosp-mirror/platform_packages_apps_packageinstaller/blob/master/src/com/android/packageinstaller/PackageInstallerActivity.java)中的PackageInstaller应用程序。
我像这样修改了processPackageUri
的PackageInstallerActivity.java
函数(添加了PackageManager.GET_SIGNATURES
标志):
case SCHEME_FILE: {
File sourceFile = new File(packageUri.getPath());
PackageParser.Package parsed = PackageUtil.getPackageInfo(sourceFile);
// Check for parse errors
if (parsed == null) {
Log.w(TAG, "Parse error when parsing manifest. Discontinuing installation");
showDialogInner(DLG_PACKAGE_ERROR);
setPmResult(PackageManager.INSTALL_FAILED_INVALID_APK);
return false;
}
mPkgInfo = PackageParser.generatePackageInfo(parsed, null,
PackageManager.GET_PERMISSIONS|PackageManager.GET_SIGNATURES, 0, 0, null,
new PackageUserState());
as = PackageUtil.getAppSnippet(this, mPkgInfo.applicationInfo, sourceFile);
} break;
签名验证功能
public boolean validateAppSignature() throws NameNotFoundException {
boolean sigMatch = false;
try {
for (Signature signature : mPkgInfo.signatures) {
// SHA1 the signature
String sha1 = getSHA1(signature.toByteArray());
// check if it matches hardcoded value
sigMatch = PLATFORM_SIGNATURE.equals(sha1);
if (sigMatch){
return sigMatch;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
我希望得到APK的签名哈希,但它抛出这个错误,(来自adb logcat)W System.err: java.lang.NullPointerException: Attempt to get length of null array
可能来自尝试部分for (Signature signature : mPkgInfo.signatures)
。我怀疑PackageParser.generatePackageInfo
部分是错误的,它没有返回任何签名。有人可以开导我吗?非常感谢。
附录:我发现PackageInstaller应用程序确实没有签名。我跟踪了代码并在src/com/android/packageinstaller/PackageUtil.java
中找到了以下内容:
public static PackageParser.Package getPackageInfo(File sourceFile) {
final PackageParser parser = new PackageParser();
try {
return parser.parsePackage(sourceFile, 0);
} catch (PackageParserException e) {
return null;
}
}
parsePackage
函数来自frameworks/base/core/java/android/content/pm/PackageParser.java
,它是这样的:
public Package parsePackage(File packageFile, int flags) throws PackageParserException {
if (packageFile.isDirectory()) {
return parseClusterPackage(packageFile, flags);
} else {
return parseMonolithicPackage(packageFile, flags);
}
}
它接受标志,但PackageUtil.java
没有传递任何标志,我认为这是我没有得到任何apk文件签名的原因。如果我想要签名,我想我可能需要从collectCertificates(Package, int)
调用PackageParser.java
。
我是在正确的轨道上吗?您的意见得到高度赞赏。
由于@ChrisStratton的评论,我设法解决了这个问题。我需要从collectCertificates
调用PackageInstallerActivity.java
,如下所示:
case SCHEME_FILE: {
File sourceFile = new File(packageUri.getPath());
PackageParser.Package parsed = PackageUtil.getPackageInfoMod(sourceFile, PackageManager.GET_PERMISSIONS|PackageManager.GET_SIGNATURES);
// Check for parse errors
if (parsed == null) {
Log.w(TAG, "Parse error when parsing manifest. Discontinuing installation");
showDialogInner(DLG_PACKAGE_ERROR);
setPmResult(PackageManager.INSTALL_FAILED_INVALID_APK);
return false;
}
else {
try {
PackageParser.collectCertificates(parsed, PackageManager.GET_SIGNATURES);
}
catch (Exception e) {
e.printStackTrace();
}
}
mPkgInfo = PackageParser.generatePackageInfo(parsed, null,
PackageManager.GET_PERMISSIONS|PackageManager.GET_SIGNATURES, 0, 0, null,
new PackageUserState());
as = PackageUtil.getAppSnippet(this, mPkgInfo.applicationInfo, sourceFile);
} break;