options: Complete the transition to numeric toggles (`#if') For the sake of review, this commit alters only the code; the affiliated comments within the source files also need to be updated, but doing so now would obscure the operational changes that have been made here. * All on/off options have been switched to the numeric `#if' variant; that is the only way to make this `default_options.h.in' thing work in a reasonable manner. * There is now some very minor compile-time checking of the user's choice of options. * NO_FAST_EXPTMOD doesn't seem to be used, so it has been removed. * ENABLE_USER_ALGO_LIST was supposed to be renamed DROPBEAR_USER_ALGO_LIST, and this commit completes that work. * DROPBEAR_FUZZ seems to be a relatively new, as-yet undocumented option, which was added by the following commit: commit 6e0b539e9ca0b5628c6c5a3d118ad6a2e79e8039 Author: Matt Johnston <[email protected]> Date: Tue May 23 22:29:21 2017 +0800 split out checkpubkey_line() separately It has now been added to `sysoptions.h' and defined as `0' by default. * The configuration option `DROPBEAR_PASSWORD_ENV' is no longer listed in `default_options.h.in'; it is no longer meant to be set by the user, and is instead left to be defined in `sysoptions.h' (where it was already being defined) as merely the name of the environment variable in question: DROPBEAR_PASSWORD To enable or disable use of that environment variable, the user must now toggle `DROPBEAR_USE_DROPBEAR_PASSWORD'. * The sFTP support is now toggled by setting `DROPBEAR_SFTPSERVER', and the path of the sFTP server program is set independently through the usual SFTPSERVER_PATH.

#ifndef DROPBEAR_DROPBEAR_ECC_H
#define DROPBEAR_DROPBEAR_ECC_H

#include "includes.h"
#include "options.h"

#include "buffer.h"

#if DROPBEAR_ECC

struct dropbear_ecc_curve {
	int ltc_size; /* to match the byte sizes in ltc_ecc_sets[] */
	const ltc_ecc_set_type *dp; /* curve domain parameters */
	const struct ltc_hash_descriptor *hash_desc;
	const char *name;
};

extern struct dropbear_ecc_curve ecc_curve_nistp256;
extern struct dropbear_ecc_curve ecc_curve_nistp384;
extern struct dropbear_ecc_curve ecc_curve_nistp521;
extern struct dropbear_ecc_curve *dropbear_ecc_curves[];

void dropbear_ecc_fill_dp(void);
struct dropbear_ecc_curve* curve_for_dp(const ltc_ecc_set_type *dp);

/* "pubkey" refers to a point, but LTC uses ecc_key structure for both public
   and private keys */
void buf_put_ecc_raw_pubkey_string(buffer *buf, ecc_key *key);
ecc_key * buf_get_ecc_raw_pubkey(buffer *buf, const struct dropbear_ecc_curve *curve);
int buf_get_ecc_privkey_string(buffer *buf, ecc_key *key);

mp_int * dropbear_ecc_shared_secret(ecc_key *pub_key, const ecc_key *priv_key);

#endif

#endif /* DROPBEAR_DROPBEAR_ECC_H */