Question

I am encrypting data using CryptProtectData function and I am getting encrypted data in LPBYTE format, I want to save that data into a file and then read back for decryption.

In order to write string in file, I used following one to convert LPBYTE data to CString:

CString strEncrUName = (wchar_t *)encryptedUN;

I even tried this one How to convert from BYTE array to CString in MFC? but still it’s not working.

Character set used is unicode.

Thanks in advance

Answer 1

The encrypted data is a buffer of raw bytes, not characters. If you want to convert it to a string, you’ll have to encode it somehow, such as by converting it to Hex chars.

eg. byte 0xd5 becomes 2 chars: “D5”

Looping through each byte and converting it to hex chars is an easy exercice left up to the reader.

Of course, you’ll have to convert it back to binary after you read the file.

Are you sure you want to save it to a text file. Your other option is to save the binary encrypted data to a binary file: no need to convert to/from string.