Decrypt FBE on 9.0 (backwards compatible)
Building in 9.0 may require you to add a flag to your twrp fstab
with the fileencryption details like:
fileencryption=ice:aes-256-heh
Verify this against your device's stock fstab of course.
Change-Id: If9286f5d5787280814daca9fbc8f5191ff26a839
diff --git a/crypto/ext4crypt/KeyBuffer.h b/crypto/ext4crypt/KeyBuffer.h
new file mode 100644
index 0000000..2087187
--- /dev/null
+++ b/crypto/ext4crypt/KeyBuffer.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#ifndef ANDROID_VOLD_KEYBUFFER_H
+#define ANDROID_VOLD_KEYBUFFER_H
+
+#include <cstring>
+#include <memory>
+#include <vector>
+
+namespace android {
+namespace vold {
+
+/**
+ * Variant of memset() that should never be optimized away. Borrowed from keymaster code.
+ */
+#ifdef __clang__
+#define OPTNONE __attribute__((optnone))
+#else // not __clang__
+#define OPTNONE __attribute__((optimize("O0")))
+#endif // not __clang__
+inline OPTNONE void* memset_s(void* s, int c, size_t n) {
+ if (!s)
+ return s;
+ return memset(s, c, n);
+}
+#undef OPTNONE
+
+// Allocator that delegates useful work to standard one but zeroes data before deallocating.
+class ZeroingAllocator : public std::allocator<char> {
+ public:
+ void deallocate(pointer p, size_type n)
+ {
+ memset_s(p, 0, n);
+ std::allocator<char>::deallocate(p, n);
+ }
+};
+
+// Char vector that zeroes memory when deallocating.
+using KeyBuffer = std::vector<char, ZeroingAllocator>;
+
+// Convenience methods to concatenate key buffers.
+KeyBuffer operator+(KeyBuffer&& lhs, const KeyBuffer& rhs);
+KeyBuffer operator+(KeyBuffer&& lhs, const char* rhs);
+
+} // namespace vold
+} // namespace android
+
+#endif
+