PBKDF2 hang (very long loop) if iterations == 0

[guidovranken]

#include <botan/pbkdf.h>
#include <botan/pwdhash.h>

#define CF_CHECK_NE(expr, res) if ( (expr) == (res) ) { goto end; }
int main(void)
{
    std::unique_ptr<::Botan::PasswordHashFamily> pwdhash_fam = nullptr;
    std::unique_ptr<::Botan::PasswordHash> pwdhash = nullptr;
    uint8_t out[1];
    char key[8] = { 0 };
    uint8_t salt[8] = { 0 };

    /* Initialize */
    {
        CF_CHECK_NE(pwdhash_fam = ::Botan::PasswordHashFamily::create("PBKDF2(SHA-256)"), nullptr);
        CF_CHECK_NE(pwdhash = pwdhash_fam->from_params(0), nullptr);
    }
    /* Process */
    {
        pwdhash->derive_key(
                out,
                1,
                key,
                sizeof(key),
                salt,
                sizeof(salt));
    }

end:
    return 0;
}

I think it might be more appropriate to throw an exception?

[randombit]

Fixed now in #2090 thanks!

[guidovranken]

You're welcome