1 /*
2 * Copyright 2023 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 //! Handle parsing of APK manifest files.
18 //! The manifest file is written as XML text, but is stored in the APK
19 //! as Android binary compressed XML. This library is a wrapper around
20 //! a thin C++ wrapper around libandroidfw, which contains the same
21 //! parsing code as used by package manager and aapt2 (amongst other
22 //! things).
23
24 use anyhow::{bail, Context, Result};
25 use apkmanifest_bindgen::{extractManifestInfo, freeManifestInfo, getPackageName, getVersionCode};
26 use std::ffi::CStr;
27 use std::fs::File;
28 use std::path::Path;
29
30 /// Information extracted from the Android manifest inside an APK.
31 #[derive(Debug, Default, Eq, PartialEq)]
32 pub struct ApkManifestInfo {
33 /// The package name of the app.
34 pub package: String,
35 /// The version code of the app.
36 pub version_code: u64,
37 }
38
39 const ANDROID_MANIFEST: &str = "AndroidManifest.xml";
40
41 /// Find the manifest inside the given APK and return information from it.
get_manifest_info<P: AsRef<Path>>(apk_path: P) -> Result<ApkManifestInfo>42 pub fn get_manifest_info<P: AsRef<Path>>(apk_path: P) -> Result<ApkManifestInfo> {
43 let apk = File::open(apk_path.as_ref())?;
44 let manifest = apkzip::read_file(apk, ANDROID_MANIFEST)?;
45
46 // Safety: The function only reads the memory range we specify and does not hold
47 // any reference to it.
48 let native_info = unsafe { extractManifestInfo(manifest.as_ptr() as _, manifest.len()) };
49 if native_info.is_null() {
50 bail!("Failed to parse manifest")
51 };
52
53 scopeguard::defer! {
54 // Safety: The value we pass is the result of calling extractManifestInfo as required.
55 // We must call this exactly once, after we have finished using it, which the scopeguard
56 // ensures.
57 unsafe { freeManifestInfo(native_info); }
58 }
59
60 // Safety: It is always safe to call this with a valid native_info, which we have,
61 // and it always returns a valid nul-terminated C string with the same lifetime as native_info.
62 // We immediately make a copy.
63 let package = unsafe { CStr::from_ptr(getPackageName(native_info)) };
64 let package = package.to_str().context("Invalid package name")?.to_string();
65
66 // Safety: It is always safe to call this with a valid native_info, which we have.
67 let version_code = unsafe { getVersionCode(native_info) };
68
69 Ok(ApkManifestInfo { package, version_code })
70 }
71