decrypt: AOSP 10 requires the use of fscrypt
fscrypt aosp doc: https://source.android.com/security/encryption/file-based
kernel fscrypt doc: https://www.kernel.org/doc/html/v4.18/filesystems/fscrypt.html
This commit implements the ability for TWRP to use fscrypt to decrypt
files on the fscrypt implementation. It has been implemented mostly
in a new successor library to e4crypt called libtwrpfscrypt. Most of the
code was ported from AOSP vold.
Notable updates include:
- updated policy storage by libtar
- lookup of fbe policies by libtwrpfscrypt
- threaded keystore operations
Big thanks to Dees_Troy for the initial trailblazing
of encryption in TWRP.
Change-Id: I69cd2eba3693a9914e00213d4943229635d0cdae
diff --git a/crypto/fscrypt/Decrypt.h b/crypto/fscrypt/Decrypt.h
new file mode 100755
index 0000000..8fb5160
--- /dev/null
+++ b/crypto/fscrypt/Decrypt.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2015 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 <stdbool.h>
+#include <sys/cdefs.h>
+
+#include <cutils/multiuser.h>
+
+#include <string>
+
+__BEGIN_DECLS
+
+// NOTE: keep in sync with StorageManager
+static constexpr int FLAG_STORAGE_DE = 1 << 0;
+static constexpr int FLAG_STORAGE_CE = 1 << 1;
+// For 9.0 Ext4CryptPie.cpp
+static constexpr int STORAGE_FLAG_DE = 1 << 0;
+static constexpr int STORAGE_FLAG_CE = 1 << 1;
+
+
+int Get_Password_Type(const userid_t user_id, std::string& filename);
+bool Decrypt_DE();
+bool Decrypt_User(const userid_t user_id, const std::string& Password);
+__END_DECLS