Remove dependency between apex_file and apex_preinstalled_data
The only reason that dependency was there is to get a trusted public key
when validating vbmeta of an apex. This responsibility is now delegated
to the caller of ValidateApexVerity.
Test: atest ApexTestCases
Bug: 165948777
Change-Id: Ibfff81c4dfd078546d3dcf3167ad624e8028a52b
Merged-In: Ibfff81c4dfd078546d3dcf3167ad624e8028a52b
(cherry picked from commit 814ca221e8862ad9db72838a23fa673c4201d8a0)
diff --git a/apexd/apex_file.cpp b/apexd/apex_file.cpp
index 36fd7c9..282595a 100644
--- a/apexd/apex_file.cpp
+++ b/apexd/apex_file.cpp
@@ -23,6 +23,7 @@
#include <filesystem>
#include <fstream>
+#include <span>
#include <android-base/file.h>
#include <android-base/logging.h>
@@ -31,18 +32,16 @@
#include <android-base/unique_fd.h>
#include <google/protobuf/util/message_differencer.h>
#include <libavb/libavb.h>
+#include <ziparchive/zip_archive.h>
#include "apex_constants.h"
-#include "apex_preinstalled_data.h"
#include "apexd_utils.h"
-#include "string_log.h"
using android::base::borrowed_fd;
using android::base::EndsWith;
using android::base::Error;
using android::base::ReadFullyAtOffset;
using android::base::Result;
-using android::base::StartsWith;
using android::base::unique_fd;
using google::protobuf::util::MessageDifferencer;
@@ -148,7 +147,7 @@
}
return ApexFile(path, image_offset, image_size, std::move(*manifest), pubkey,
- isPathForBuiltinApexes(path), *fs_type);
+ *fs_type);
}
// AVB-related code.
@@ -214,8 +213,10 @@
memcmp(&public_key_content[0], key, length) == 0;
}
-Result<void> verifyVbMetaSignature(const ApexFile& apex, const uint8_t* data,
- size_t length) {
+// Verifies correctness of vbmeta and returns public key it was signed with.
+Result<std::span<const uint8_t>> verifyVbMetaSignature(const ApexFile& apex,
+ const uint8_t* data,
+ size_t length) {
const uint8_t* pk;
size_t pk_len;
AvbVBMetaVerifyResult res;
@@ -236,31 +237,16 @@
return Error() << "Error verifying " << apex.GetPath() << ": "
<< "unsupported version";
default:
- return Errorf("Unknown vmbeta_image_verify return value");
+ return Error() << "Unknown vmbeta_image_verify return value : " << res;
}
- auto& instance = ApexPreinstalledData::GetInstance();
- // TODO(b/165948777): extract into verifier.
- Result<const std::string> public_key =
- instance.GetPublicKey(apex.GetManifest().name());
- if (public_key.ok()) {
- // TODO(b/115718846)
- // We need to decide whether we need rollback protection, and whether
- // we can use the rollback protection provided by libavb.
- if (!CompareKeys(pk, pk_len, *public_key)) {
- return Error() << "Error verifying " << apex.GetPath() << ": "
- << "public key doesn't match the pre-installed one";
- }
- } else {
- return public_key.error();
- }
- LOG(VERBOSE) << apex.GetPath() << ": public key matches.";
- return {};
+ return std::span<const uint8_t>(pk, pk_len);
}
Result<std::unique_ptr<uint8_t[]>> verifyVbMeta(const ApexFile& apex,
const unique_fd& fd,
- const AvbFooter& footer) {
+ const AvbFooter& footer,
+ const std::string& public_key) {
if (footer.vbmeta_size > kVbMetaMaxSize) {
return Errorf("VbMeta size in footer exceeds kVbMetaMaxSize.");
}
@@ -272,12 +258,17 @@
return ErrnoError() << "Couldn't read AVB meta-data";
}
- Result<void> st =
+ Result<std::span<const uint8_t>> st =
verifyVbMetaSignature(apex, vbmeta_buf.get(), footer.vbmeta_size);
if (!st.ok()) {
return st.error();
}
+ if (!CompareKeys(st->data(), st->size(), public_key)) {
+ return Error() << "Error verifying " << apex.GetPath() << " : "
+ << "public key doesn't match the pre-installed one";
+ }
+
return vbmeta_buf;
}
@@ -329,7 +320,8 @@
} // namespace
-Result<ApexVerityData> ApexFile::VerifyApexVerity() const {
+Result<ApexVerityData> ApexFile::VerifyApexVerity(
+ const std::string& public_key) const {
ApexVerityData verityData;
unique_fd fd(open(GetPath().c_str(), O_RDONLY | O_CLOEXEC));
@@ -343,7 +335,7 @@
}
Result<std::unique_ptr<uint8_t[]>> vbmeta_data =
- verifyVbMeta(*this, fd, **footer);
+ verifyVbMeta(*this, fd, **footer, public_key);
if (!vbmeta_data.ok()) {
return vbmeta_data.error();
}
@@ -420,14 +412,5 @@
return ReadDir(path, filter_fn);
}
-bool isPathForBuiltinApexes(const std::string& path) {
- for (const auto& dir : kApexPackageBuiltinDirs) {
- if (StartsWith(path, dir)) {
- return true;
- }
- }
- return false;
-}
-
} // namespace apex
} // namespace android
