[This is preliminary documentation and subject to change.]
The EncryptFile function encrypts a file or directory. All data streams in a file are encrypted. All new files created in an encrypted directory are encrypted.
BOOL EncryptFile(
LPCTSTR lpFileName
);
The caller must have FILE_READ_DATA, FILE_WRITE_DATA, FILE_READ_ATTRIBUTES, FILE_WRITE_ATTRIBUTES, and SYNCHRONIZE access to the file.
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
The EncryptFile function requires exclusive access to the file being encrypted, and will fail another process is using the file.
If the file is already encrypted, EncryptFile simply returns a nonzero value, which indicates success. If the file is compressed, EncryptFile will decompress the file before encrypting it.
To decrypt an encrypted file, use the DecryptFile function.
Windows NT: Requires version 5.0 or later.
Windows: Unsupported.
Windows CE: Unsupported.
Header: Declared in winbase.h.
Import Library: Use kernel32.lib.
Unicode: Implemented as Unicode and ANSI versions on Windows NT.
File Systems Overview, File System Functions, DecryptFile