Re: [NSE + NSELib] Netbios and SMB [stable!]

[Ron <ron () skullsecurity net>]

Ron wrote:
> Sven Klemm wrote:
>
> Hey Sven,
>
> I got the MD4() stuff working, and it's working well. But I'm having a
> problem with the DES(), and it's probably my own fault for not knowing
> OpenSSL well enough. I'm trying to encrypt the string "KGS!@#$%" using
> the key "part1" (which is a 7-character string). But it's returning
> 'nil'. Am I doing this wrong, and/or is there a way to tell what I'm
> doing incorrectly?
>
> The 7-character string should have the parity bits set and become a
> 8-character key, which is used to encrypt the constant string. That's
> how I understand it to work, anyways.
>
> Here's the relevant code:
>     return openssl.encrypt("DES-ECB", part1, nil, "KGS!@#$%", false)
>
> Thanks!
> Ron

So, I got to the point where it'll return me an encrypted string, that
was my own fault (wasn't returning the right variable). But I still
can't get it to encrypt the string the way I want it. Again, this is
likely due to a lack of my own understanding.

This is how I do it in C:

-----------------------
static void password_to_key(const uint8_t password[7], uint8_t key[8])
{
    /* make room for parity bits */
    key[0] =                        (password[0] >> 0);
    key[1] = ((password[0]) << 7) | (password[1] >> 1);
    key[2] = ((password[1]) << 6) | (password[2] >> 2);
    key[3] = ((password[2]) << 5) | (password[3] >> 3);
    key[5] = ((password[3]) << 4) | (password[4] >> 4);
    key[5] = ((password[4]) << 3) | (password[5] >> 5);
    key[6] = ((password[5]) << 2) | (password[6] >> 6);
    key[7] = ((password[6]) << 1);
}

static void des(const uint8_t password[7], const uint8_t data[8],
uint8_t result[])
{
    DES_cblock key;
    DES_key_schedule schedule;

    password_to_key(password, key);

    DES_set_odd_parity(&key);
    DES_set_key_unchecked(&key, &schedule);
    DES_ecb_encrypt((DES_cblock*)data, (DES_cblock*)result, &schedule,
DES_ENCRYPT);
}
-----------------------

Anybody know how I can replicate that in OpenSSL, using the
EVP_CIPHER-style functions?



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