Have a similar API like tokio::fs::File, tokio::fs and tokio::fs::OpenOptions that can work with EncryptedFs. We should have CryptoFile with a similar API like File that wraps corresponding crypto structs.

Structure of crypto module

• crypto::fs_api::fs::OpenOptions
• crypto::fs_api::fs::File
• crypto::fs_api::fs
• crypto::fs_api::io investigate if we really need this
• crypto::fs_api::path::Path. This is because the exists method uses local fs
• crypto::fs_api::path::PathBuf. This is because the exists method uses local fs

Flow

• Use crypto::fs_api::fs::OpenOptionsto create a crypto::fs_apifs::File
• Internally, the File will split the path by OS's path separator and call EncryptedFs::find_by_name until it gets the no for the file.
• Then will call EncryptedFs::[open_read, open_write] with the ino, which will return a CryptoReadSeek or CryptoWriteSeek and the fh (file handle), which will be used on read, write and seek methods of Read and Write traits
• When the File object is dropped, we close the handle with EncryptedFs::release
• Read or write to file with crypto::fs_api::io

Flow is like this

lib-users > crypto::fs_api::[fs, fs::OpenOptions, fs::File, io] > EncryptedFs -> crypto::storage_api::[fs, fs::OpenOptions, fs::File, io]

This issue corresponds to lib-users > crypto::fs_api::[fs, fs::OpenOptions, fs::File, io] > EncryptedFs.

The advantage is that a lib user could use encrypted files just like regular files by "just" changing the use statements, such as using files like json or yaml. A good use case is that users could build a password manager or encrypted sticky notes.

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