commit	9d5a125db8dc98996897adedec5d2bfb69c6f78f	[log] [tgz]
author	Alex Klyubin <klyubin@google.com>	Sat Mar 18 15:35:36 2017 -0700
committer	Alex Klyubin <klyubin@google.com>	Thu Apr 27 20:50:45 2017 +0000
tree	e9a2acac25d8decccd4fc4443506059e18759f68
parent	1fafac434119b6c43208d610384353cd0802b93a [diff]

ASN.1 BER data value reader

This commit adds an ASN.1 Basic Encoding Rules (BER) data value reader
which returns data values, one by one, from a source (e.g., ByteBuffer
or InputStream containing the data values in their BER encoded form).
The interpretation of the data values (e.g., how to obtain a numeric
value from an INTEGER data value, or how to extract the elements of a
SEQUENCE data value) is left to callers of the BER data value reader.

This commit also adds a number of AllTests classes which organize all
test classes into one large test suite. The reason is Bazel which makes
it hard to simply run all tests in a subtree without having to pull in
third-party dependencies. A finer-grained alternative is to create a
java_test target per test class, but that requires creating
java_library targets for shared classes, such as test utils, and this
in turn requires adding an explicit dependency on junit4 which is a
pain because there's no portable way to specify this.

Test: bazel test ...
Test: gradlew test
Bug: 31517633
Change-Id: Ie14647f877378f5fd1aa35dc36c5d682aa364e89

18 files changed

tree: e9a2acac25d8decccd4fc4443506059e18759f68

README.md

apksig

apksig is a project which aims to simplify APK signing and checking whether APK's signatures should verify on Android. apksig supports JAR signing (used by Android since day one) and APK Signature Scheme v2 (supported since Android Nougat, API Level 24).

The key feature of apksig is that it knows about differences in APK signature verification logic between different versions of the Android platform. apksig can thus check whether a signed APK is expected to verify on all Android platform versions supported by the APK. When signing an APK, apksig will choose the most appropriate cryptographic algorithms based on the Android platform versions supported by the APK being signed.

The project consists of two subprojects:

apksig -- a pure Java library, and
apksigner -- a pure Java command-line tool based on the apksig library.

apksig library

apksig library offers three primitives:

ApkSigner which signs the provided APK so that it verifies on all Android platform versions supported by the APK. The range of platform versions can be customized if necessary.
ApkVerifier which checks whether the provided APK is expected to verify on all Android platform versions supported by the APK. The range of platform versions can be customized if necessary.
(Default)ApkSignerEngine which abstracts away signing an APK from parsing and building an APK file. This is useful in optimized APK building pipelines, such as in Android Plugin for Gradle, which need to perform signing while building an APK, instead of after. For simpler use cases where the APK to be signed is available upfront, the ApkSigner above is easier to use.

NOTE: Some public classes of the library are in packages having the word “internal” in their name. These are not public API of the library. Do not use *.internal.* classes directly.

apksigner command-line tool

apksigner command-line tool offers two operations:

sign the provided APK so that it verifies on all Android platforms supported by the APK. Run apksigner sign for usage information.
check whether the provided APK's signatures are expected to verify on all Android platforms supported by the APK. Run apksigner verify for usage information.

The tool determines the range of Android platform versions (API Levels) supported by the APK by inspecting the APK's AndroidManifest.xml. This behavior can be overridden by specifying the range of platform versions on the command-line.