I want to check whether a string is encrypted by RSA algorithm or not. This encryption checker must implemented in Kernel mode and worse than that it has to write in Win XP. I investigate OpenSSL and especially its RSA_public_decrypt but this function solely work in user mode and unfortunately I haven't saw the code. I supposed to verify a text with the given public key and signature. I don't want to implement it by scratch since I have to manipulate with multiply big numbers.
Any bit advice will be noticeable Sincerely yours