|author||Michael Groover <email@example.com>||Tue Apr 06 15:10:02 2021 -0700|
|committer||Michael Groover <firstname.lastname@example.org>||Wed Apr 07 15:02:18 2021 -0700|
Add support for deterministic DSA signing This commit adds support for deterministic DSA signing (RFC6979) using the Java signature algorithm SHA256withDetDSA. Note that this signature algorithm may not be supported by the default Security Providers and may require adding an additional Provider. The deterministic signature is still a valid signature and can be verified using the same process to verify a standard DSA signature. Bug: 169266066 Test: gradlew test Change-Id: I80bd17302814411c0feaea8a7e6a08e80476d7ef
apksig is a project which aims to simplify APK signing and checking whether APK signatures are expected to 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). apksig is meant to be used outside of Android devices.
The key feature of apksig is that it knows about differences in APK signature verification logic between different versions of the Android platform. apksig thus thoroughly checks whether an APK's signature is expected to verify on all Android platform versions supported by the APK. When signing an APK, apksig chooses the most appropriate cryptographic algorithms based on the Android platform versions supported by the APK being signed.
The project consists of two subprojects:
apksig library offers three primitives:
ApkSignerwhich 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.
ApkVerifierwhich 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.
(Default)ApkSignerEnginewhich abstracts away signing APKs from parsing and building APKs. 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
ApkSignerabove 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 because these classes may change any time without regard to existing clients outside of
apksigner command-line tool offers two operations:
apksigner signfor usage information.
apksigner verifyfor 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.