Using Win32 Crypto API

Question

I can't find any help to implement PROV_RSA_AES CSP in c++. is there any article or book to help me out with it?

Do you actually want to implement a CSP? Or do you just want to use one? — Rasmus Faber, Oct 15 '09 at 15:20
i just want to use one, i figured how to get context but i'm still thinking about the size of buffer i need to use for CryptEncrypt() to get it working with aes256 ? i also want to use random salt. — Dave_19, Oct 17 '09 at 04:29

Sani Huttunen · Answer 1 · 2009-10-14T15:05:20.957

0

Here is an article about it.
Here is another one.

edited Oct 14 '09 at 15:05

answered Oct 14 '09 at 14:59

Sani Huttunen

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i can't find the first part of this article. – Dave_19 Oct 14 '09 at 15:02
the other one uses PROV_RSA_FULL. – Dave_19 Oct 14 '09 at 15:07
You should be able to figure out the rest with those two articles. – Sani Huttunen Oct 14 '09 at 15:59

score 0 · Answer 2 · answered Oct 19 '09 at 14:39

i just want to use one, i figured how to get context but i'm still thinking about the size of buffer i need to use for CryptEncrypt() to get it working with aes256 ? i also want to use random salt.

AES256 in CBC-mode with PKCS#7-padding (which is the default) will need a buffersize that is the input-data rounded up to the next multiple of 16 (but always at least one byte more). Ie. 35 -> 48, 52 -> 64, 80 -> 96.

There is no salt involved in AES256. Are you talking about key-derivation? Or do you mean the IV?

Using Win32 Crypto API

2 Answers2