Parse APK manifest to extract version etc
Add libapkmanifest to encapsulate the parsing, with a small C++
library on top of libandroidfw.
Extract the zip-handling code from libapkverify into a separate
libapkzip, and fix up a bunch of tests tests, to keep the build happy.
We don't do anything with the manifest information except log it; more
to come in another CL.
Bug: 299591171
Test: atest libapkzip.test libapkverify.integration_test
libapkverify.test
Test: Manual - run VM, inspect logs.
Change-Id: I56d3bb7309d43ecb598a33320705d31948710f83
diff --git a/libs/apkmanifest/native/apkmanifest.cpp b/libs/apkmanifest/native/apkmanifest.cpp
new file mode 100644
index 0000000..ab0ba72
--- /dev/null
+++ b/libs/apkmanifest/native/apkmanifest.cpp
@@ -0,0 +1,207 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "apkmanifest.hpp"
+
+#include <android-base/logging.h>
+#include <android-base/result.h>
+#include <androidfw/AssetsProvider.h>
+#include <androidfw/ResourceTypes.h>
+#include <androidfw/StringPiece.h>
+#include <androidfw/Util.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <utils/Errors.h>
+
+#include <cstdlib>
+#include <limits>
+#include <string>
+#include <string_view>
+
+using android::Asset;
+using android::AssetsProvider;
+using android::OK;
+using android::Res_value;
+using android::ResXMLParser;
+using android::ResXMLTree;
+using android::statusToString;
+using android::StringPiece16;
+using android::base::Error;
+using android::base::Result;
+using android::util::Utf16ToUtf8;
+using std::u16string_view;
+using std::unique_ptr;
+
+struct ApkManifestInfo {
+ std::string package;
+ uint32_t version_code;
+ uint32_t version_code_major;
+};
+
+namespace {
+// See https://developer.android.com/guide/topics/manifest/manifest-element
+constexpr u16string_view MANIFEST_TAG_NAME{u"manifest"};
+constexpr u16string_view ANDROID_NAMESPACE_URL{u"http://schemas.android.com/apk/res/android"};
+constexpr u16string_view PACKAGE_ATTRIBUTE_NAME{u"package"};
+constexpr u16string_view VERSION_CODE_ATTRIBUTE_NAME{u"versionCode"};
+constexpr u16string_view VERSION_CODE_MAJOR_ATTRIBUTE_NAME{u"versionCodeMajor"};
+
+// Read through the XML parse tree up to the <manifest> element.
+Result<void> findManifestElement(ResXMLTree& tree) {
+ for (;;) {
+ ResXMLParser::event_code_t event = tree.next();
+ switch (event) {
+ case ResXMLParser::END_DOCUMENT:
+ case ResXMLParser::END_TAG:
+ case ResXMLParser::TEXT:
+ default:
+ return Error() << "Unexpected XML parsing event: " << event;
+ case ResXMLParser::BAD_DOCUMENT:
+ return Error() << "Failed to parse XML: " << statusToString(tree.getError());
+ case ResXMLParser::START_NAMESPACE:
+ case ResXMLParser::END_NAMESPACE:
+ // Not of interest, keep going.
+ break;
+ case ResXMLParser::START_TAG:
+ // The first tag in an AndroidManifest.xml should be <manifest> (no namespace).
+ // And that's actually the only tag we care about.
+ if (tree.getElementNamespaceID() >= 0) {
+ return Error() << "Root element has unexpected namespace.";
+ }
+ size_t nameLength = 0;
+ const char16_t* nameChars = tree.getElementName(&nameLength);
+ if (!nameChars) {
+ return Error() << "Missing tag name";
+ }
+ if (u16string_view(nameChars, nameLength) != MANIFEST_TAG_NAME) {
+ return Error() << "Expected <manifest> as root element";
+ }
+ return {};
+ }
+ }
+}
+
+// Return an attribute encoded as a string, converted to UTF-8. Note that all
+// attributes are strings in the original XML, but the binary format encodes
+// some as binary numbers etc. This function does not handle converting those
+// encodings back to strings, so should only be used when it is known that a
+// numeric value is not allowed.
+Result<std::string> getStringOnlyAttribute(const ResXMLTree& tree, size_t index) {
+ size_t len;
+ const char16_t* value = tree.getAttributeStringValue(index, &len);
+ if (!value) {
+ return Error() << "Expected attribute to have string value";
+ }
+ return Utf16ToUtf8(StringPiece16(value, len));
+}
+
+// Return the u32 value of an attribute.
+Result<uint32_t> getU32Attribute(const ResXMLTree& tree, size_t index) {
+ auto type = tree.getAttributeDataType(index);
+ switch (type) {
+ case Res_value::TYPE_INT_DEC:
+ case Res_value::TYPE_INT_HEX:
+ // This is how we'd expect the version to be encoded - and we don't
+ // care what base it was originally in.
+ return tree.getAttributeData(index);
+ case Res_value::TYPE_STRING: {
+ // If the original string is encoded, then we need to convert it.
+ auto str = OR_RETURN(getStringOnlyAttribute(tree, index));
+ char* str_end = nullptr;
+ // Note that by specifying base 0 we allow for octal, hex, or
+ // decimal representations here.
+ unsigned long value = std::strtoul(str.c_str(), &str_end, 0);
+ if (str_end != str.c_str() + str.size() ||
+ value > std::numeric_limits<uint32_t>::max()) {
+ return Error() << "Invalid numeric value";
+ }
+ return static_cast<uint32_t>(value);
+ }
+ default:
+ return Error() << "Expected numeric value, got type " << type;
+ }
+}
+
+// Parse the binary manifest and extract the information we care about.
+// Everything we're interested in should be an attribute on the <manifest> tag.
+// We don't care what order they come in, absent attributes will be treated as
+// the default value, and any unknown attributes (including ones not in the
+// expected namespace) will be ignored.
+Result<unique_ptr<ApkManifestInfo>> parseManifest(const void* manifest, size_t size) {
+ ResXMLTree tree;
+ auto status = tree.setTo(manifest, size);
+ if (status != OK) {
+ return Error() << "Failed to create XML Tree: " << statusToString(status);
+ }
+
+ OR_RETURN(findManifestElement(tree));
+
+ unique_ptr<ApkManifestInfo> info{new ApkManifestInfo{}};
+
+ size_t count = tree.getAttributeCount();
+ for (size_t i = 0; i < count; ++i) {
+ size_t len;
+ const char16_t* chars;
+
+ chars = tree.getAttributeNamespace(i, &len);
+ auto namespaceUrl = chars ? u16string_view(chars, len) : u16string_view();
+
+ chars = tree.getAttributeName(i, &len);
+ auto attributeName = chars ? u16string_view(chars, len) : u16string_view();
+
+ if (namespaceUrl.empty()) {
+ if (attributeName == PACKAGE_ATTRIBUTE_NAME) {
+ auto result = getStringOnlyAttribute(tree, i);
+ if (!result.ok()) return Error() << "Package name: " << result.error();
+ info->package = *result;
+ }
+ } else if (namespaceUrl == ANDROID_NAMESPACE_URL) {
+ if (attributeName == VERSION_CODE_ATTRIBUTE_NAME) {
+ auto result = getU32Attribute(tree, i);
+ if (!result.ok()) return Error() << "Version code: " << result.error();
+ info->version_code = *result;
+ } else if (attributeName == VERSION_CODE_MAJOR_ATTRIBUTE_NAME) {
+ auto result = getU32Attribute(tree, i);
+ if (!result.ok()) return Error() << "Version code major: " << result.error();
+ info->version_code_major = *result;
+ }
+ }
+ }
+
+ return info;
+}
+} // namespace
+
+const ApkManifestInfo* extractManifestInfo(const void* manifest, size_t size) {
+ auto result = parseManifest(manifest, size);
+ if (!result.ok()) {
+ LOG(ERROR) << "Failed to parse APK manifest:" << result.error().message();
+ return nullptr;
+ }
+ return result->release();
+}
+
+void freeManifestInfo(const ApkManifestInfo* info) {
+ delete info;
+}
+
+const char* getPackageName(const ApkManifestInfo* info) {
+ return info->package.c_str();
+}
+
+uint64_t getVersionCode(const ApkManifestInfo* info) {
+ return info->version_code | (static_cast<uint64_t>(info->version_code_major) << 32);
+}