Adding a separate lib for random seed generation
Adding a lib which produces fuzzer seeds from recorded transaction.
It includes utility which reverses bytes from given value based
on the ranges provided.
Test: m libbinder_random_parcel_seeds
Bug: 278975837
Change-Id: Ic6f27b4d8eec6329a9437af9a8ec217c76fbef19
diff --git a/libs/binder/tests/parcel_fuzzer/Android.bp b/libs/binder/tests/parcel_fuzzer/Android.bp
index 35866ad..0d1503e 100644
--- a/libs/binder/tests/parcel_fuzzer/Android.bp
+++ b/libs/binder/tests/parcel_fuzzer/Android.bp
@@ -104,3 +104,28 @@
local_include_dirs: ["include_random_parcel"],
export_include_dirs: ["include_random_parcel"],
}
+
+cc_library {
+ name: "libbinder_random_parcel_seeds",
+ host_supported: true,
+ vendor_available: true,
+ target: {
+ darwin: {
+ enabled: false,
+ },
+ },
+ srcs: [
+ "random_parcel_seeds.cpp",
+ ],
+ shared_libs: [
+ "libbase",
+ "libbinder",
+ "libbinder_ndk",
+ "libcutils",
+ "libutils",
+ ],
+ local_include_dirs: [
+ "include_random_parcel_seeds",
+ ],
+ export_include_dirs: ["include_random_parcel_seeds"],
+}
diff --git a/libs/binder/tests/parcel_fuzzer/include_random_parcel_seeds/fuzzseeds/random_parcel_seeds.h b/libs/binder/tests/parcel_fuzzer/include_random_parcel_seeds/fuzzseeds/random_parcel_seeds.h
new file mode 100644
index 0000000..6cceb06
--- /dev/null
+++ b/libs/binder/tests/parcel_fuzzer/include_random_parcel_seeds/fuzzseeds/random_parcel_seeds.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 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 <android-base/file.h>
+#include <android-base/hex.h>
+#include <android-base/logging.h>
+
+#include <binder/Binder.h>
+#include <binder/Parcel.h>
+#include <binder/RecordedTransaction.h>
+
+#include <private/android_filesystem_config.h>
+
+#include <vector>
+
+using android::Parcel;
+using android::base::HexString;
+using std::vector;
+
+namespace android {
+namespace impl {
+// computes the bytes so that if they are passed to FuzzedDataProvider and
+// provider.ConsumeIntegralInRange<T>(min, max) is called, it will return val
+template <typename T>
+void writeReversedBuffer(std::vector<std::byte>& integralBuffer, T min, T max, T val);
+
+// Calls writeInBuffer method with min and max numeric limits of type T. This method
+// is reversal of ConsumeIntegral<T>() in FuzzedDataProvider
+template <typename T>
+void writeReversedBuffer(std::vector<std::byte>& integralBuffer, T val);
+} // namespace impl
+void generateSeedsFromRecording(base::borrowed_fd fd,
+ binder::debug::RecordedTransaction&& transaction);
+} // namespace android
diff --git a/libs/binder/tests/parcel_fuzzer/random_parcel_seeds.cpp b/libs/binder/tests/parcel_fuzzer/random_parcel_seeds.cpp
new file mode 100644
index 0000000..7c66683
--- /dev/null
+++ b/libs/binder/tests/parcel_fuzzer/random_parcel_seeds.cpp
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 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 <android-base/file.h>
+#include <android-base/logging.h>
+
+#include <binder/RecordedTransaction.h>
+
+#include <fuzzseeds/random_parcel_seeds.h>
+
+using android::base::WriteFully;
+
+namespace android {
+namespace impl {
+template <typename T>
+std::vector<uint8_t> reverseBytes(T min, T max, T val) {
+ uint64_t range = static_cast<uint64_t>(max) - min;
+ uint64_t result = val - min;
+ size_t offset = 0;
+
+ std::vector<uint8_t> reverseData;
+ uint8_t reversed = 0;
+ reversed |= result;
+
+ while (offset < sizeof(T) * CHAR_BIT && (range >> offset) > 0) {
+ reverseData.push_back(reversed);
+ reversed = 0;
+ reversed |= (result >> CHAR_BIT);
+ result = result >> CHAR_BIT;
+ offset += CHAR_BIT;
+ }
+
+ return std::move(reverseData);
+}
+
+template <typename T>
+void writeReversedBuffer(std::vector<uint8_t>& integralBuffer, T min, T max, T val) {
+ std::vector<uint8_t> reversedData = reverseBytes(min, max, val);
+ // ConsumeIntegral Calls read buffer from the end. Keep inserting at the front of the buffer
+ // so that we can align fuzzService operations with seed generation for readability.
+ integralBuffer.insert(integralBuffer.begin(), reversedData.begin(), reversedData.end());
+}
+
+template <typename T>
+void writeReversedBuffer(std::vector<uint8_t>& integralBuffer, T val) {
+ // For ConsumeIntegral<T>() calls, FuzzedDataProvider uses numeric limits min and max
+ // as range
+ writeReversedBuffer(integralBuffer, std::numeric_limits<T>::min(),
+ std::numeric_limits<T>::max(), val);
+}
+
+} // namespace impl
+
+void generateSeedsFromRecording(base::borrowed_fd fd,
+ binder::debug::RecordedTransaction&& transaction) {
+ // Write Reserved bytes for future use
+ std::vector<uint8_t> reservedBytes(8);
+ CHECK(WriteFully(fd, reservedBytes.data(), reservedBytes.size())) << fd.get();
+
+ std::vector<uint8_t> integralBuffer;
+
+ // Write UID array : Array elements are initialized in the order that they are declared
+ // UID array index 2 element
+ // int64_t aidRoot = 0;
+ impl::writeReversedBuffer(integralBuffer, static_cast<int64_t>(AID_ROOT) << 32,
+ static_cast<int64_t>(AID_USER) << 32,
+ static_cast<int64_t>(AID_ROOT) << 32);
+
+ // UID array index 3 element
+ impl::writeReversedBuffer(integralBuffer, static_cast<int64_t>(AID_ROOT) << 32);
+
+ // always pick AID_ROOT -> index 0
+ size_t uidIndex = 0;
+ impl::writeReversedBuffer(integralBuffer, static_cast<size_t>(0), static_cast<size_t>(3),
+ uidIndex);
+
+ // Never set uid in seed corpus
+ uint8_t writeUid = 0;
+ impl::writeReversedBuffer(integralBuffer, writeUid);
+
+ // Read random code. this will be from recorded transaction
+ uint8_t selectCode = 1;
+ impl::writeReversedBuffer(integralBuffer, selectCode);
+
+ // Get from recorded transaction
+ uint32_t code = transaction.getCode();
+ impl::writeReversedBuffer(integralBuffer, code);
+
+ // Get from recorded transaction
+ uint32_t flags = transaction.getFlags();
+ impl::writeReversedBuffer(integralBuffer, flags);
+
+ // always fuzz primary binder
+ size_t extraBindersIndex = 0;
+ impl::writeReversedBuffer(integralBuffer, static_cast<size_t>(0), static_cast<size_t>(0),
+ extraBindersIndex);
+
+ const Parcel& dataParcel = transaction.getDataParcel();
+
+ // This buffer holds the bytes which will be used for fillRandomParcel API
+ std::vector<uint8_t> fillParcelBuffer;
+
+ // Don't take rpc path
+ uint8_t rpcBranch = 0;
+ impl::writeReversedBuffer(fillParcelBuffer, rpcBranch);
+
+ // Implicit branch on this path -> options->writeHeader(p, provider)
+ uint8_t writeHeaderInternal = 0;
+ impl::writeReversedBuffer(fillParcelBuffer, writeHeaderInternal);
+
+ // Choose to write data in parcel
+ size_t fillFuncIndex = 0;
+ impl::writeReversedBuffer(fillParcelBuffer, static_cast<size_t>(0), static_cast<size_t>(2),
+ fillFuncIndex);
+
+ // Write parcel data size from recorded transaction
+ size_t toWrite = transaction.getDataParcel().dataBufferSize();
+ impl::writeReversedBuffer(fillParcelBuffer, static_cast<size_t>(0), toWrite, toWrite);
+
+ // Write parcel data with size towrite from recorded transaction
+ CHECK(WriteFully(fd, dataParcel.data(), toWrite)) << fd.get();
+
+ // Write Fill Parcel buffer size in integralBuffer so that fuzzService knows size of data
+ size_t subDataSize = toWrite + fillParcelBuffer.size();
+ impl::writeReversedBuffer(integralBuffer, static_cast<size_t>(0), subDataSize, subDataSize);
+
+ // Write fill parcel buffer
+ CHECK(WriteFully(fd, fillParcelBuffer.data(), fillParcelBuffer.size())) << fd.get();
+
+ // Write the integralBuffer to data
+ CHECK(WriteFully(fd, integralBuffer.data(), integralBuffer.size())) << fd.get();
+}
+} // namespace android