/*
ecdh.c -- Diffie-Hellman key exchange handling
- Copyright (C) 2011 Guus Sliepen <guus@tinc-vpn.org>
+ Copyright (C) 2011-2013 Guus Sliepen <guus@tinc-vpn.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#include "system.h"
-#include "utils.h"
-#include "xalloc.h"
+#include "../system.h"
#include <openssl/err.h>
#include <openssl/ec.h>
+#include <openssl/ecdh.h>
#include <openssl/obj_mac.h>
-#include "ecdh.h"
-#include "logger.h"
+#define __TINC_ECDH_INTERNAL__
+typedef EC_KEY ecdh_t;
-EC_GROUP *secp256k1 = NULL;
-EC_GROUP *secp384r1 = NULL;
-EC_GROUP *secp521r1 = NULL;
+#include "../ecdh.h"
+#include "../logger.h"
+#include "../utils.h"
+#include "../xalloc.h"
-// TODO: proper KDF
-static void *kdf(const void *in, size_t inlen, void *out, size_t *outlen) {
- memcpy(out, in, inlen);
- *outlen = inlen;
- return out;
-}
-
-bool ecdh_generate_public(ecdh_t *ecdh, void *pubkey) {
- if(!secp521r1)
- secp521r1 = EC_GROUP_new_by_curve_name(NID_secp521r1);
+ecdh_t *ecdh_generate_public(void *pubkey) {
+ ecdh_t *ecdh = EC_KEY_new_by_curve_name(NID_secp521r1);
+ if(!ecdh) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Generating EC key_by_curve_name failed: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
- *ecdh = EC_KEY_new_by_curve_name(NID_secp521r1);
- if(!EC_KEY_generate_key(*ecdh)) {
- logger(LOG_ERR, "Generating EC key failed: %s", ERR_error_string(ERR_get_error(), NULL));
- abort();
+ if(!EC_KEY_generate_key(ecdh)) {
+ EC_KEY_free(ecdh);
+ logger(DEBUG_ALWAYS, LOG_ERR, "Generating EC key failed: %s", ERR_error_string(ERR_get_error(), NULL));
+ return NULL;
}
-
- const EC_POINT *point = EC_KEY_get0_public_key(*ecdh);
+
+ const EC_POINT *point = EC_KEY_get0_public_key(ecdh);
if(!point) {
- logger(LOG_ERR, "Getting public key failed: %s", ERR_error_string(ERR_get_error(), NULL));
- abort();
+ EC_KEY_free(ecdh);
+ logger(DEBUG_ALWAYS, LOG_ERR, "Getting public key failed: %s", ERR_error_string(ERR_get_error(), NULL));
+ return NULL;
}
- size_t result = EC_POINT_point2oct(secp521r1, point, POINT_CONVERSION_COMPRESSED, pubkey, ECDH_SIZE, NULL);
+ size_t result = EC_POINT_point2oct(EC_KEY_get0_group(ecdh), point, POINT_CONVERSION_COMPRESSED, pubkey, ECDH_SIZE, NULL);
if(!result) {
- logger(LOG_ERR, "Converting EC_POINT to binary failed: %s", ERR_error_string(ERR_get_error(), NULL));
- abort();
+ EC_KEY_free(ecdh);
+ logger(DEBUG_ALWAYS, LOG_ERR, "Converting EC_POINT to binary failed: %s", ERR_error_string(ERR_get_error(), NULL));
+ return NULL;
}
- return true;
+ return ecdh;
}
bool ecdh_compute_shared(ecdh_t *ecdh, const void *pubkey, void *shared) {
- EC_POINT *point = EC_POINT_new(secp521r1);
-
- int result = EC_POINT_oct2point(secp521r1, point, pubkey, ECDH_SIZE, NULL);
+ EC_POINT *point = EC_POINT_new(EC_KEY_get0_group(ecdh));
if(!point) {
- logger(LOG_ERR, "Converting binary to EC_POINT failed: %s", ERR_error_string(ERR_get_error(), NULL));
- abort();
+ logger(DEBUG_ALWAYS, LOG_ERR, "EC_POINT_new() failed: %s", ERR_error_string(ERR_get_error(), NULL));
+ EC_KEY_free(ecdh);
+ return false;
}
- result = ECDH_compute_key(shared, ECDH_SIZE, point, *ecdh, kdf);
+ int result = EC_POINT_oct2point(EC_KEY_get0_group(ecdh), point, pubkey, ECDH_SIZE, NULL);
+ if(!result) {
+ EC_POINT_free(point);
+ EC_KEY_free(ecdh);
+ logger(DEBUG_ALWAYS, LOG_ERR, "Converting binary to EC_POINT failed: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+
+ result = ECDH_compute_key(shared, ECDH_SIZE, point, ecdh, NULL);
EC_POINT_free(point);
- EC_KEY_free(*ecdh);
- *ecdh = NULL;
+ EC_KEY_free(ecdh);
if(!result) {
- logger(LOG_ERR, "Computing Elliptic Curve Diffie-Hellman shared key failed: %s", ERR_error_string(ERR_get_error(), NULL));
+ logger(DEBUG_ALWAYS, LOG_ERR, "Computing Elliptic Curve Diffie-Hellman shared key failed: %s", ERR_error_string(ERR_get_error(), NULL));
return false;
}
return true;
}
+
+void ecdh_free(ecdh_t *ecdh) {
+ if(ecdh)
+ EC_KEY_free(ecdh);
+}