| commit | 24aeb9bff8b6479397960eadac9283cc8a509f0b | [log] [tgz] |
|---|---|---|
| author | Michael Groover <mpgroover@google.com> | Wed Jul 14 19:06:47 2021 -0700 |
| committer | Michael Groover <mpgroover@google.com> | Wed Jul 14 19:06:47 2021 -0700 |
| tree | bf94d74e160ea0a3b5cc5c2354a81ba62c09e54e | |
| parent | b03b5c31c123365e8d2c34c3b7fd578ef7829a2d [diff] |
Add support for Conscrypt APK sig verify with negative modulus It is possible for an APK's signing certificate to be improperly encoded such that the RSA modulus is negative (the modulus has a leading 1 in the encoding without a preceding zero byte to encode the integer as positive). While many Providers can handle this and will reencode the public key with the positive value of the modulus, the conscrypt provider will use the OID value for the public key's algorithm (as opposed to the expected "RSA"), and can fail when parsing the public key during a call to Signature#initVerify. This commit adds checks for the RSA OID value when checking the PublicKey's algorithm, and will also attempt to reencode the public key during the V1 signature verification if Signature#initVerify fails with an InvalidKeyException. Bug: 181120429 Test: gradlew test Change-Id: Ib34abfd67f0637a45a79dd981c669b5096c1570c
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:
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.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.(Default)ApkSignerEngine which 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 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 because these classes may change any time without regard to existing clients outside of apksig and apksigner.
apksigner command-line tool offers two operations:
apksigner sign for usage information.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.