2012-12-30 21:06:11 +01:00
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/*
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* Simultaneous authentication of equals
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2013-01-01 11:18:44 +01:00
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* Copyright (c) 2012-2013, Jouni Malinen <j@w1.fi>
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2012-12-30 21:06:11 +01:00
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*
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* This software may be distributed under the terms of the BSD license.
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* See README for more details.
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*/
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#include "includes.h"
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#include "common.h"
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2012-12-31 18:41:21 +01:00
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#include "crypto/crypto.h"
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2012-12-30 21:06:11 +01:00
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#include "crypto/sha256.h"
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#include "crypto/random.h"
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2013-01-05 20:22:00 +01:00
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#include "crypto/dh_groups.h"
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2012-12-30 21:16:18 +01:00
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#include "ieee802_11_defs.h"
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2012-12-30 21:06:11 +01:00
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#include "sae.h"
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2013-01-01 10:29:53 +01:00
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int sae_set_group(struct sae_data *sae, int group)
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{
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2013-01-05 20:22:00 +01:00
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sae_clear_data(sae);
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/* First, check if this is an ECC group */
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2013-01-01 10:29:53 +01:00
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sae->ec = crypto_ec_init(group);
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2013-01-05 20:22:00 +01:00
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if (sae->ec) {
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sae->group = group;
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sae->prime_len = crypto_ec_prime_len(sae->ec);
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sae->prime = crypto_ec_get_prime(sae->ec);
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sae->order = crypto_ec_get_order(sae->ec);
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return 0;
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}
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2013-01-01 10:29:53 +01:00
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2013-01-05 20:22:00 +01:00
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/* Not an ECC group, check FFC */
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sae->dh = dh_groups_get(group);
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if (sae->dh) {
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sae->group = group;
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sae->prime_len = sae->dh->prime_len;
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if (sae->prime_len > SAE_MAX_PRIME_LEN) {
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sae_clear_data(sae);
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return -1;
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}
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2013-01-01 10:29:53 +01:00
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2013-01-05 20:22:00 +01:00
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sae->prime_buf = crypto_bignum_init_set(sae->dh->prime,
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sae->prime_len);
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if (sae->prime_buf == NULL) {
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sae_clear_data(sae);
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return -1;
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}
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sae->prime = sae->prime_buf;
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2013-01-06 14:13:07 +01:00
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sae->order_buf = crypto_bignum_init_set(sae->dh->order,
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sae->dh->order_len);
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if (sae->order_buf == NULL) {
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2013-01-05 20:22:00 +01:00
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sae_clear_data(sae);
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return -1;
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}
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sae->order = sae->order_buf;
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return 0;
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}
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/* Unsupported group */
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return -1;
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2013-01-01 10:29:53 +01:00
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}
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2013-01-06 18:06:59 +01:00
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void sae_clear_temp_data(struct sae_data *sae)
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2013-01-01 10:29:53 +01:00
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{
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if (sae == NULL)
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return;
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crypto_ec_deinit(sae->ec);
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2013-01-06 18:06:59 +01:00
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sae->ec = NULL;
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sae->dh = NULL;
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2013-01-05 20:22:00 +01:00
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crypto_bignum_deinit(sae->prime_buf, 0);
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2013-01-06 18:06:59 +01:00
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sae->prime_buf = NULL;
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sae->prime = NULL;
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2013-01-05 20:22:00 +01:00
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crypto_bignum_deinit(sae->order_buf, 0);
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2013-01-06 18:06:59 +01:00
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sae->order_buf = NULL;
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sae->order = NULL;
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2013-01-06 14:32:38 +01:00
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crypto_bignum_deinit(sae->sae_rand, 1);
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2013-01-06 18:06:59 +01:00
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sae->sae_rand = NULL;
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2013-01-06 15:10:48 +01:00
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crypto_bignum_deinit(sae->pwe_ffc, 1);
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2013-01-06 18:06:59 +01:00
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sae->pwe_ffc = NULL;
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2013-01-06 15:57:53 +01:00
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crypto_bignum_deinit(sae->own_commit_scalar, 0);
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2013-01-06 18:06:59 +01:00
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sae->own_commit_scalar = NULL;
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2013-01-06 17:12:58 +01:00
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crypto_bignum_deinit(sae->own_commit_element_ffc, 0);
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2013-01-06 18:06:59 +01:00
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sae->own_commit_element_ffc = NULL;
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2013-01-06 17:12:58 +01:00
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crypto_bignum_deinit(sae->peer_commit_element_ffc, 0);
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2013-01-06 18:06:59 +01:00
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sae->peer_commit_element_ffc = NULL;
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2013-01-06 15:10:48 +01:00
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crypto_ec_point_deinit(sae->pwe_ecc, 1);
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2013-01-06 18:06:59 +01:00
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sae->pwe_ecc = NULL;
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2013-01-06 17:12:58 +01:00
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crypto_ec_point_deinit(sae->own_commit_element_ecc, 0);
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2013-01-06 18:06:59 +01:00
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sae->own_commit_element_ecc = NULL;
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2013-01-06 17:12:58 +01:00
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crypto_ec_point_deinit(sae->peer_commit_element_ecc, 0);
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2013-01-06 18:06:59 +01:00
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sae->peer_commit_element_ecc = NULL;
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}
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void sae_clear_data(struct sae_data *sae)
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{
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if (sae == NULL)
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return;
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sae_clear_temp_data(sae);
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crypto_bignum_deinit(sae->peer_commit_scalar, 0);
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2013-01-01 10:29:53 +01:00
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os_memset(sae, 0, sizeof(*sae));
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}
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2013-01-01 13:00:40 +01:00
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static void buf_shift_right(u8 *buf, size_t len, size_t bits)
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{
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size_t i;
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for (i = len - 1; i > 0; i--)
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buf[i] = (buf[i - 1] << (8 - bits)) | (buf[i] >> bits);
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buf[0] >>= bits;
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}
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2013-01-06 14:47:37 +01:00
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static struct crypto_bignum * sae_get_rand(struct sae_data *sae)
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2012-12-30 21:06:11 +01:00
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{
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2013-01-06 14:32:38 +01:00
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u8 val[SAE_MAX_PRIME_LEN];
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2012-12-30 21:06:11 +01:00
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int iter = 0;
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2013-01-06 14:47:37 +01:00
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struct crypto_bignum *bn = NULL;
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int order_len_bits = crypto_bignum_bits(sae->order);
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2013-01-06 14:13:07 +01:00
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size_t order_len = (order_len_bits + 7) / 8;
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2013-01-06 14:32:38 +01:00
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if (order_len > sizeof(val))
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return NULL;
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2012-12-30 21:06:11 +01:00
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2013-01-06 14:47:37 +01:00
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for (;;) {
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2012-12-30 21:06:11 +01:00
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if (iter++ > 100)
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2013-01-06 14:32:38 +01:00
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return NULL;
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2013-01-06 14:13:07 +01:00
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if (random_get_bytes(val, order_len) < 0)
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2013-01-06 14:32:38 +01:00
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return NULL;
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2013-01-06 14:13:07 +01:00
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if (order_len_bits % 8)
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buf_shift_right(val, order_len, 8 - order_len_bits % 8);
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2013-01-06 14:47:37 +01:00
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bn = crypto_bignum_init_set(val, order_len);
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if (bn == NULL)
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return NULL;
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2013-01-06 17:38:17 +01:00
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if (crypto_bignum_is_zero(bn) ||
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crypto_bignum_is_one(bn) ||
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crypto_bignum_cmp(bn, sae->order) >= 0)
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2013-01-06 14:47:37 +01:00
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continue;
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break;
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}
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2012-12-30 21:06:11 +01:00
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2013-01-06 14:32:38 +01:00
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os_memset(val, 0, order_len);
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return bn;
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2012-12-30 21:06:11 +01:00
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}
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2013-01-01 11:18:44 +01:00
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static struct crypto_bignum * sae_get_rand_and_mask(struct sae_data *sae)
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2013-01-05 20:22:00 +01:00
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{
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2013-01-06 14:32:38 +01:00
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crypto_bignum_deinit(sae->sae_rand, 1);
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2013-01-06 14:47:37 +01:00
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sae->sae_rand = sae_get_rand(sae);
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2013-01-06 14:32:38 +01:00
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if (sae->sae_rand == NULL)
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2013-01-05 20:22:00 +01:00
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return NULL;
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2013-01-06 14:47:37 +01:00
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return sae_get_rand(sae);
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2013-01-05 20:22:00 +01:00
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}
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2012-12-30 21:06:11 +01:00
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static void sae_pwd_seed_key(const u8 *addr1, const u8 *addr2, u8 *key)
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{
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wpa_printf(MSG_DEBUG, "SAE: PWE derivation - addr1=" MACSTR
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" addr2=" MACSTR, MAC2STR(addr1), MAC2STR(addr2));
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if (os_memcmp(addr1, addr2, ETH_ALEN) > 0) {
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os_memcpy(key, addr1, ETH_ALEN);
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os_memcpy(key + ETH_ALEN, addr2, ETH_ALEN);
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} else {
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os_memcpy(key, addr2, ETH_ALEN);
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os_memcpy(key + ETH_ALEN, addr1, ETH_ALEN);
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}
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}
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2013-01-06 17:30:11 +01:00
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static int sae_test_pwd_seed_ecc(struct sae_data *sae, const u8 *pwd_seed,
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struct crypto_ec_point *pwe)
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2012-12-30 21:06:11 +01:00
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{
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2013-01-06 17:12:58 +01:00
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u8 pwd_value[SAE_MAX_ECC_PRIME_LEN], prime[SAE_MAX_ECC_PRIME_LEN];
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2012-12-31 18:41:21 +01:00
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struct crypto_bignum *x;
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2012-12-30 21:06:11 +01:00
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int y_bit;
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2013-01-01 13:00:40 +01:00
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size_t bits;
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2012-12-30 21:06:11 +01:00
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2013-01-05 20:12:29 +01:00
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if (crypto_bignum_to_bin(sae->prime, prime, sizeof(prime),
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sae->prime_len) < 0)
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2013-01-01 11:27:00 +01:00
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return -1;
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2013-01-01 10:52:49 +01:00
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wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-seed", pwd_seed, SHA256_MAC_LEN);
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2012-12-30 21:06:11 +01:00
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/* pwd-value = KDF-z(pwd-seed, "SAE Hunting and Pecking", p) */
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2013-01-01 13:00:40 +01:00
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bits = crypto_ec_prime_len_bits(sae->ec);
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sha256_prf_bits(pwd_seed, SHA256_MAC_LEN, "SAE Hunting and Pecking",
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prime, sae->prime_len, pwd_value, bits);
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if (bits % 8)
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buf_shift_right(pwd_value, sizeof(pwd_value), 8 - bits % 8);
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2012-12-30 21:06:11 +01:00
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wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-value",
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2013-01-01 11:45:18 +01:00
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pwd_value, sae->prime_len);
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2012-12-30 21:06:11 +01:00
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2013-01-01 11:27:00 +01:00
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if (os_memcmp(pwd_value, prime, sae->prime_len) >= 0)
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2012-12-30 21:06:11 +01:00
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return 0;
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y_bit = pwd_seed[SHA256_MAC_LEN - 1] & 0x01;
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2013-01-01 11:45:18 +01:00
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x = crypto_bignum_init_set(pwd_value, sae->prime_len);
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2012-12-30 21:06:11 +01:00
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if (x == NULL)
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return -1;
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2013-01-01 10:37:58 +01:00
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if (crypto_ec_point_solve_y_coord(sae->ec, pwe, x, y_bit) < 0) {
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2012-12-31 18:41:21 +01:00
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crypto_bignum_deinit(x, 0);
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2012-12-30 21:06:11 +01:00
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wpa_printf(MSG_DEBUG, "SAE: No solution found");
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return 0;
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}
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2012-12-31 18:41:21 +01:00
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crypto_bignum_deinit(x, 0);
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2012-12-30 21:06:11 +01:00
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wpa_printf(MSG_DEBUG, "SAE: PWE found");
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return 1;
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}
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2013-01-06 17:30:11 +01:00
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static int sae_test_pwd_seed_ffc(struct sae_data *sae, const u8 *pwd_seed,
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struct crypto_bignum *pwe)
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2013-01-05 20:22:00 +01:00
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{
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2013-01-06 17:38:17 +01:00
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u8 pwd_value[SAE_MAX_PRIME_LEN];
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2013-01-05 20:22:00 +01:00
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size_t bits = sae->prime_len * 8;
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u8 exp[1];
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struct crypto_bignum *a, *b;
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int res;
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wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-seed", pwd_seed, SHA256_MAC_LEN);
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/* pwd-value = KDF-z(pwd-seed, "SAE Hunting and Pecking", p) */
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sha256_prf_bits(pwd_seed, SHA256_MAC_LEN, "SAE Hunting and Pecking",
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sae->dh->prime, sae->prime_len, pwd_value, bits);
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if (bits % 8)
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buf_shift_right(pwd_value, sizeof(pwd_value), 8 - bits % 8);
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wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-value", pwd_value, sae->prime_len);
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if (os_memcmp(pwd_value, sae->dh->prime, sae->prime_len) >= 0) {
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wpa_printf(MSG_DEBUG, "SAE: pwd-value >= p");
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return 0;
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}
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/* PWE = pwd-value^((p-1)/r) modulo p */
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a = crypto_bignum_init_set(pwd_value, sae->prime_len);
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2013-01-06 14:13:07 +01:00
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if (sae->dh->safe_prime) {
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2013-01-05 20:22:00 +01:00
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/*
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* r = (p-1)/2 for the group used here, so this becomes:
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* PWE = pwd-value^2 modulo p
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*/
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exp[0] = 2;
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b = crypto_bignum_init_set(exp, sizeof(exp));
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} else {
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2013-01-06 17:56:46 +01:00
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/* Calculate exponent: (p-1)/r */
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2013-01-05 20:22:00 +01:00
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exp[0] = 1;
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b = crypto_bignum_init_set(exp, sizeof(exp));
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2013-01-06 17:56:46 +01:00
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if (b == NULL ||
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crypto_bignum_sub(sae->prime, b, b) < 0 ||
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crypto_bignum_div(b, sae->order, b) < 0) {
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crypto_bignum_deinit(b, 0);
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b = NULL;
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}
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2013-01-05 20:22:00 +01:00
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}
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2013-01-06 17:56:46 +01:00
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if (a == NULL || b == NULL)
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res = -1;
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else
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res = crypto_bignum_exptmod(a, b, sae->prime, pwe);
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2013-01-05 20:22:00 +01:00
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crypto_bignum_deinit(a, 0);
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crypto_bignum_deinit(b, 0);
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|
|
if (res < 0) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Failed to calculate PWE");
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* if (PWE > 1) --> found */
|
2013-01-06 17:38:17 +01:00
|
|
|
if (crypto_bignum_is_zero(pwe) || crypto_bignum_is_one(pwe)) {
|
2013-01-05 20:22:00 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: PWE <= 1");
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: PWE found");
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 17:30:11 +01:00
|
|
|
static int sae_derive_pwe_ecc(struct sae_data *sae, const u8 *addr1,
|
|
|
|
const u8 *addr2, const u8 *password,
|
|
|
|
size_t password_len)
|
|
|
|
{
|
|
|
|
u8 counter, k = 4;
|
|
|
|
u8 addrs[2 * ETH_ALEN];
|
|
|
|
const u8 *addr[2];
|
|
|
|
size_t len[2];
|
|
|
|
int found = 0;
|
|
|
|
struct crypto_ec_point *pwe_tmp;
|
|
|
|
|
|
|
|
if (sae->pwe_ecc == NULL) {
|
|
|
|
sae->pwe_ecc = crypto_ec_point_init(sae->ec);
|
|
|
|
if (sae->pwe_ecc == NULL)
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
pwe_tmp = crypto_ec_point_init(sae->ec);
|
|
|
|
if (pwe_tmp == NULL)
|
|
|
|
return -1;
|
|
|
|
|
|
|
|
wpa_hexdump_ascii_key(MSG_DEBUG, "SAE: password",
|
|
|
|
password, password_len);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* H(salt, ikm) = HMAC-SHA256(salt, ikm)
|
|
|
|
* pwd-seed = H(MAX(STA-A-MAC, STA-B-MAC) || MIN(STA-A-MAC, STA-B-MAC),
|
|
|
|
* password || counter)
|
|
|
|
*/
|
|
|
|
sae_pwd_seed_key(addr1, addr2, addrs);
|
|
|
|
|
|
|
|
addr[0] = password;
|
|
|
|
len[0] = password_len;
|
|
|
|
addr[1] = &counter;
|
|
|
|
len[1] = sizeof(counter);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Continue for at least k iterations to protect against side-channel
|
|
|
|
* attacks that attempt to determine the number of iterations required
|
|
|
|
* in the loop.
|
|
|
|
*/
|
|
|
|
for (counter = 1; counter < k || !found; counter++) {
|
|
|
|
u8 pwd_seed[SHA256_MAC_LEN];
|
|
|
|
int res;
|
|
|
|
|
|
|
|
if (counter > 200) {
|
|
|
|
/* This should not happen in practice */
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Failed to derive PWE");
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: counter = %u", counter);
|
|
|
|
if (hmac_sha256_vector(addrs, sizeof(addrs), 2, addr, len,
|
|
|
|
pwd_seed) < 0)
|
|
|
|
break;
|
|
|
|
res = sae_test_pwd_seed_ecc(sae, pwd_seed,
|
|
|
|
found ? pwe_tmp : sae->pwe_ecc);
|
|
|
|
if (res < 0)
|
|
|
|
break;
|
|
|
|
if (res == 0)
|
|
|
|
continue;
|
|
|
|
if (found) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Ignore this PWE (one was "
|
|
|
|
"already selected)");
|
|
|
|
} else {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Use this PWE");
|
|
|
|
found = 1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
crypto_ec_point_deinit(pwe_tmp, 1);
|
|
|
|
|
|
|
|
return found ? 0 : -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static int sae_derive_pwe_ffc(struct sae_data *sae, const u8 *addr1,
|
|
|
|
const u8 *addr2, const u8 *password,
|
|
|
|
size_t password_len)
|
2013-01-05 20:22:00 +01:00
|
|
|
{
|
|
|
|
u8 counter;
|
|
|
|
u8 addrs[2 * ETH_ALEN];
|
|
|
|
const u8 *addr[2];
|
|
|
|
size_t len[2];
|
|
|
|
int found = 0;
|
|
|
|
|
2013-01-06 15:10:48 +01:00
|
|
|
if (sae->pwe_ffc == NULL) {
|
|
|
|
sae->pwe_ffc = crypto_bignum_init();
|
|
|
|
if (sae->pwe_ffc == NULL)
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
2013-01-05 20:22:00 +01:00
|
|
|
wpa_hexdump_ascii_key(MSG_DEBUG, "SAE: password",
|
|
|
|
password, password_len);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* H(salt, ikm) = HMAC-SHA256(salt, ikm)
|
|
|
|
* pwd-seed = H(MAX(STA-A-MAC, STA-B-MAC) || MIN(STA-A-MAC, STA-B-MAC),
|
|
|
|
* password || counter)
|
|
|
|
*/
|
|
|
|
sae_pwd_seed_key(addr1, addr2, addrs);
|
|
|
|
|
|
|
|
addr[0] = password;
|
|
|
|
len[0] = password_len;
|
|
|
|
addr[1] = &counter;
|
|
|
|
len[1] = sizeof(counter);
|
|
|
|
|
|
|
|
for (counter = 1; !found; counter++) {
|
|
|
|
u8 pwd_seed[SHA256_MAC_LEN];
|
|
|
|
int res;
|
|
|
|
|
|
|
|
if (counter > 200) {
|
|
|
|
/* This should not happen in practice */
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Failed to derive PWE");
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: counter = %u", counter);
|
|
|
|
if (hmac_sha256_vector(addrs, sizeof(addrs), 2, addr, len,
|
|
|
|
pwd_seed) < 0)
|
|
|
|
break;
|
2013-01-06 17:30:11 +01:00
|
|
|
res = sae_test_pwd_seed_ffc(sae, pwd_seed, sae->pwe_ffc);
|
2013-01-05 20:22:00 +01:00
|
|
|
if (res < 0)
|
|
|
|
break;
|
|
|
|
if (res > 0) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Use this PWE");
|
|
|
|
found = 1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return found ? 0 : -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 17:47:52 +01:00
|
|
|
static int sae_derive_commit_element_ecc(struct sae_data *sae,
|
|
|
|
struct crypto_bignum *mask)
|
2013-01-06 17:30:11 +01:00
|
|
|
{
|
|
|
|
/* COMMIT-ELEMENT = inverse(scalar-op(mask, PWE)) */
|
|
|
|
if (!sae->own_commit_element_ecc) {
|
|
|
|
sae->own_commit_element_ecc = crypto_ec_point_init(sae->ec);
|
|
|
|
if (!sae->own_commit_element_ecc)
|
2013-01-06 17:47:52 +01:00
|
|
|
return -1;
|
2013-01-06 17:30:11 +01:00
|
|
|
}
|
2013-01-06 17:47:52 +01:00
|
|
|
|
2013-01-06 17:30:11 +01:00
|
|
|
if (crypto_ec_point_mul(sae->ec, sae->pwe_ecc, mask,
|
|
|
|
sae->own_commit_element_ecc) < 0 ||
|
|
|
|
crypto_ec_point_invert(sae->ec, sae->own_commit_element_ecc) < 0) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Could not compute commit-element");
|
2013-01-06 17:47:52 +01:00
|
|
|
return -1;
|
2013-01-06 17:30:11 +01:00
|
|
|
}
|
|
|
|
|
2013-01-06 17:47:52 +01:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static int sae_derive_commit_element_ffc(struct sae_data *sae,
|
|
|
|
struct crypto_bignum *mask)
|
|
|
|
{
|
|
|
|
/* COMMIT-ELEMENT = inverse(scalar-op(mask, PWE)) */
|
|
|
|
if (!sae->own_commit_element_ffc) {
|
|
|
|
sae->own_commit_element_ffc = crypto_bignum_init();
|
|
|
|
if (!sae->own_commit_element_ffc)
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (crypto_bignum_exptmod(sae->pwe_ffc, mask, sae->prime,
|
|
|
|
sae->own_commit_element_ffc) < 0 ||
|
|
|
|
crypto_bignum_inverse(sae->own_commit_element_ffc, sae->prime,
|
|
|
|
sae->own_commit_element_ffc) < 0) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Could not compute commit-element");
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
2013-01-06 17:30:11 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 17:47:52 +01:00
|
|
|
static int sae_derive_commit(struct sae_data *sae)
|
2013-01-05 20:22:00 +01:00
|
|
|
{
|
2013-01-06 17:12:58 +01:00
|
|
|
struct crypto_bignum *mask;
|
2013-01-05 20:22:00 +01:00
|
|
|
int ret = -1;
|
|
|
|
|
2013-01-06 14:47:37 +01:00
|
|
|
mask = sae_get_rand_and_mask(sae);
|
2013-01-05 20:22:00 +01:00
|
|
|
if (mask == NULL) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Could not get rand/mask");
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
2013-01-06 17:12:58 +01:00
|
|
|
/* commit-scalar = (rand + mask) modulo r */
|
2013-01-06 15:57:53 +01:00
|
|
|
if (!sae->own_commit_scalar) {
|
|
|
|
sae->own_commit_scalar = crypto_bignum_init();
|
|
|
|
if (!sae->own_commit_scalar)
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
crypto_bignum_add(sae->sae_rand, mask, sae->own_commit_scalar);
|
|
|
|
crypto_bignum_mod(sae->own_commit_scalar, sae->order,
|
|
|
|
sae->own_commit_scalar);
|
2013-01-05 20:22:00 +01:00
|
|
|
|
2013-01-06 17:47:52 +01:00
|
|
|
if (sae->ec && sae_derive_commit_element_ecc(sae, mask) < 0)
|
|
|
|
goto fail;
|
|
|
|
if (sae->dh && sae_derive_commit_element_ffc(sae, mask) < 0)
|
2013-01-05 20:22:00 +01:00
|
|
|
goto fail;
|
|
|
|
|
|
|
|
ret = 0;
|
|
|
|
fail:
|
|
|
|
crypto_bignum_deinit(mask, 1);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
int sae_prepare_commit(const u8 *addr1, const u8 *addr2,
|
|
|
|
const u8 *password, size_t password_len,
|
|
|
|
struct sae_data *sae)
|
|
|
|
{
|
2013-01-06 17:47:52 +01:00
|
|
|
if (sae->ec && sae_derive_pwe_ecc(sae, addr1, addr2, password,
|
|
|
|
password_len) < 0)
|
|
|
|
return -1;
|
|
|
|
if (sae->dh && sae_derive_pwe_ffc(sae, addr1, addr2, password,
|
|
|
|
password_len) < 0)
|
|
|
|
return -1;
|
|
|
|
if (sae_derive_commit(sae) < 0)
|
|
|
|
return -1;
|
|
|
|
return 0;
|
2013-01-05 20:22:00 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 17:30:11 +01:00
|
|
|
static int sae_derive_k_ecc(struct sae_data *sae, u8 *k)
|
2012-12-30 21:16:18 +01:00
|
|
|
{
|
2013-01-06 17:12:58 +01:00
|
|
|
struct crypto_ec_point *K;
|
2012-12-30 21:16:18 +01:00
|
|
|
int ret = -1;
|
|
|
|
|
2013-01-01 10:37:58 +01:00
|
|
|
K = crypto_ec_point_init(sae->ec);
|
2013-01-06 17:12:58 +01:00
|
|
|
if (K == NULL)
|
2012-12-30 21:16:18 +01:00
|
|
|
goto fail;
|
|
|
|
|
2013-01-06 17:12:58 +01:00
|
|
|
if (!crypto_ec_point_is_on_curve(sae->ec, sae->peer_commit_element_ecc))
|
|
|
|
{
|
2012-12-30 21:16:18 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Peer element is not on curve");
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* K = scalar-op(rand, (elem-op(scalar-op(peer-commit-scalar, PWE),
|
|
|
|
* PEER-COMMIT-ELEMENT)))
|
|
|
|
* If K is identity element (point-at-infinity), reject
|
|
|
|
* k = F(K) (= x coordinate)
|
|
|
|
*/
|
|
|
|
|
2013-01-06 15:57:53 +01:00
|
|
|
if (crypto_ec_point_mul(sae->ec, sae->pwe_ecc, sae->peer_commit_scalar,
|
|
|
|
K) < 0 ||
|
2013-01-06 17:12:58 +01:00
|
|
|
crypto_ec_point_add(sae->ec, K, sae->peer_commit_element_ecc, K) < 0
|
|
|
|
||
|
2013-01-06 14:32:38 +01:00
|
|
|
crypto_ec_point_mul(sae->ec, K, sae->sae_rand, K) < 0 ||
|
2013-01-01 10:37:58 +01:00
|
|
|
crypto_ec_point_is_at_infinity(sae->ec, K) ||
|
|
|
|
crypto_ec_point_to_bin(sae->ec, K, k, NULL) < 0) {
|
2012-12-30 21:16:18 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Failed to calculate K and k");
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
|
2013-01-01 10:46:02 +01:00
|
|
|
wpa_hexdump_key(MSG_DEBUG, "SAE: k", k, sae->prime_len);
|
2012-12-30 21:16:18 +01:00
|
|
|
|
|
|
|
ret = 0;
|
|
|
|
fail:
|
2012-12-31 18:41:21 +01:00
|
|
|
crypto_ec_point_deinit(K, 1);
|
2012-12-30 21:16:18 +01:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 17:30:11 +01:00
|
|
|
static int sae_derive_k_ffc(struct sae_data *sae, u8 *k)
|
2013-01-05 20:22:00 +01:00
|
|
|
{
|
2013-01-06 17:12:58 +01:00
|
|
|
struct crypto_bignum *K;
|
2013-01-05 20:22:00 +01:00
|
|
|
int ret = -1;
|
|
|
|
|
|
|
|
K = crypto_bignum_init();
|
2013-01-06 17:12:58 +01:00
|
|
|
if (K == NULL)
|
2013-01-05 20:22:00 +01:00
|
|
|
goto fail;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* K = scalar-op(rand, (elem-op(scalar-op(peer-commit-scalar, PWE),
|
|
|
|
* PEER-COMMIT-ELEMENT)))
|
|
|
|
* If K is identity element (one), reject.
|
|
|
|
* k = F(K) (= x coordinate)
|
|
|
|
*/
|
|
|
|
|
2013-01-06 15:57:53 +01:00
|
|
|
if (crypto_bignum_exptmod(sae->pwe_ffc, sae->peer_commit_scalar,
|
|
|
|
sae->prime, K) < 0 ||
|
2013-01-06 17:12:58 +01:00
|
|
|
crypto_bignum_mulmod(K, sae->peer_commit_element_ffc, sae->prime, K)
|
|
|
|
< 0 ||
|
2013-01-06 14:32:38 +01:00
|
|
|
crypto_bignum_exptmod(K, sae->sae_rand, sae->prime, K) < 0 ||
|
2013-01-06 17:38:17 +01:00
|
|
|
crypto_bignum_is_one(K) ||
|
|
|
|
crypto_bignum_to_bin(K, k, SAE_MAX_PRIME_LEN, sae->prime_len) < 0) {
|
2013-01-05 20:22:00 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Failed to calculate K and k");
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
|
|
|
|
wpa_hexdump_key(MSG_DEBUG, "SAE: k", k, sae->prime_len);
|
|
|
|
|
|
|
|
ret = 0;
|
|
|
|
fail:
|
|
|
|
crypto_bignum_deinit(K, 1);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2012-12-31 18:41:21 +01:00
|
|
|
static int sae_derive_keys(struct sae_data *sae, const u8 *k)
|
2012-12-30 21:16:18 +01:00
|
|
|
{
|
2013-01-01 10:52:49 +01:00
|
|
|
u8 null_key[SAE_KEYSEED_KEY_LEN], val[SAE_MAX_PRIME_LEN];
|
2012-12-30 21:16:18 +01:00
|
|
|
u8 keyseed[SHA256_MAC_LEN];
|
2013-01-01 10:52:49 +01:00
|
|
|
u8 keys[SAE_KCK_LEN + SAE_PMK_LEN];
|
2013-01-06 15:57:53 +01:00
|
|
|
struct crypto_bignum *tmp;
|
2012-12-30 21:16:18 +01:00
|
|
|
int ret = -1;
|
|
|
|
|
2012-12-31 18:41:21 +01:00
|
|
|
tmp = crypto_bignum_init();
|
2013-01-06 15:57:53 +01:00
|
|
|
if (tmp == NULL)
|
2012-12-30 21:16:18 +01:00
|
|
|
goto fail;
|
|
|
|
|
|
|
|
/* keyseed = H(<0>32, k)
|
|
|
|
* KCK || PMK = KDF-512(keyseed, "SAE KCK and PMK",
|
|
|
|
* (commit-scalar + peer-commit-scalar) modulo r)
|
|
|
|
* PMKID = L((commit-scalar + peer-commit-scalar) modulo r, 0, 128)
|
|
|
|
*/
|
|
|
|
|
|
|
|
os_memset(null_key, 0, sizeof(null_key));
|
2013-01-01 10:46:02 +01:00
|
|
|
hmac_sha256(null_key, sizeof(null_key), k, sae->prime_len, keyseed);
|
2012-12-30 21:16:18 +01:00
|
|
|
wpa_hexdump_key(MSG_DEBUG, "SAE: keyseed", keyseed, sizeof(keyseed));
|
|
|
|
|
2013-01-06 15:57:53 +01:00
|
|
|
crypto_bignum_add(sae->own_commit_scalar, sae->peer_commit_scalar, tmp);
|
2013-01-05 20:12:29 +01:00
|
|
|
crypto_bignum_mod(tmp, sae->order, tmp);
|
2013-01-01 10:46:02 +01:00
|
|
|
crypto_bignum_to_bin(tmp, val, sizeof(val), sae->prime_len);
|
2013-01-01 10:52:49 +01:00
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: PMKID", val, SAE_PMKID_LEN);
|
2012-12-30 21:16:18 +01:00
|
|
|
sha256_prf(keyseed, sizeof(keyseed), "SAE KCK and PMK",
|
2013-01-01 10:46:02 +01:00
|
|
|
val, sae->prime_len, keys, sizeof(keys));
|
2013-01-01 10:52:49 +01:00
|
|
|
os_memcpy(sae->kck, keys, SAE_KCK_LEN);
|
|
|
|
os_memcpy(sae->pmk, keys + SAE_KCK_LEN, SAE_PMK_LEN);
|
|
|
|
wpa_hexdump_key(MSG_DEBUG, "SAE: KCK", sae->kck, SAE_KCK_LEN);
|
|
|
|
wpa_hexdump_key(MSG_DEBUG, "SAE: PMK", sae->pmk, SAE_PMK_LEN);
|
2012-12-30 21:16:18 +01:00
|
|
|
|
|
|
|
ret = 0;
|
|
|
|
fail:
|
2012-12-31 18:41:21 +01:00
|
|
|
crypto_bignum_deinit(tmp, 0);
|
2012-12-30 21:16:18 +01:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
int sae_process_commit(struct sae_data *sae)
|
|
|
|
{
|
2013-01-01 10:49:01 +01:00
|
|
|
u8 k[SAE_MAX_PRIME_LEN];
|
2013-01-06 17:59:46 +01:00
|
|
|
if ((sae->ec && sae_derive_k_ecc(sae, k) < 0) ||
|
|
|
|
(sae->dh && sae_derive_k_ffc(sae, k) < 0) ||
|
|
|
|
sae_derive_keys(sae, k) < 0)
|
2012-12-30 21:16:18 +01:00
|
|
|
return -1;
|
2012-12-31 18:41:21 +01:00
|
|
|
return 0;
|
2012-12-30 21:16:18 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2012-12-31 15:58:36 +01:00
|
|
|
void sae_write_commit(struct sae_data *sae, struct wpabuf *buf,
|
|
|
|
const struct wpabuf *token)
|
2012-12-30 21:06:11 +01:00
|
|
|
{
|
2013-01-06 17:12:58 +01:00
|
|
|
u8 *pos;
|
2013-01-01 10:29:53 +01:00
|
|
|
wpabuf_put_le16(buf, sae->group); /* Finite Cyclic Group */
|
2012-12-31 15:58:36 +01:00
|
|
|
if (token)
|
|
|
|
wpabuf_put_buf(buf, token);
|
2013-01-06 17:12:58 +01:00
|
|
|
pos = wpabuf_put(buf, sae->prime_len);
|
|
|
|
crypto_bignum_to_bin(sae->own_commit_scalar, pos, sae->prime_len,
|
2013-01-06 15:57:53 +01:00
|
|
|
sae->prime_len);
|
2013-01-06 17:12:58 +01:00
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: own commit-scalar", pos, sae->prime_len);
|
|
|
|
if (sae->ec) {
|
|
|
|
pos = wpabuf_put(buf, 2 * sae->prime_len);
|
|
|
|
crypto_ec_point_to_bin(sae->ec, sae->own_commit_element_ecc,
|
|
|
|
pos, pos + sae->prime_len);
|
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: own commit-element(x)",
|
|
|
|
pos, sae->prime_len);
|
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: own commit-element(y)",
|
|
|
|
pos + sae->prime_len, sae->prime_len);
|
|
|
|
} else {
|
|
|
|
pos = wpabuf_put(buf, sae->prime_len);
|
|
|
|
crypto_bignum_to_bin(sae->own_commit_element_ffc, pos,
|
|
|
|
sae->prime_len, sae->prime_len);
|
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: own commit-element",
|
|
|
|
pos, sae->prime_len);
|
|
|
|
}
|
2012-12-30 21:06:11 +01:00
|
|
|
}
|
2012-12-30 21:16:18 +01:00
|
|
|
|
|
|
|
|
2013-01-06 16:03:09 +01:00
|
|
|
static u16 sae_group_allowed(struct sae_data *sae, int *allowed_groups,
|
|
|
|
u16 group)
|
2012-12-30 21:16:18 +01:00
|
|
|
{
|
2013-01-01 15:23:47 +01:00
|
|
|
if (allowed_groups) {
|
|
|
|
int i;
|
|
|
|
for (i = 0; allowed_groups[i] >= 0; i++) {
|
|
|
|
if (allowed_groups[i] == group)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
if (allowed_groups[i] != group) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Proposed group %u not "
|
|
|
|
"enabled in the current configuration",
|
|
|
|
group);
|
|
|
|
return WLAN_STATUS_FINITE_CYCLIC_GROUP_NOT_SUPPORTED;
|
|
|
|
}
|
|
|
|
}
|
2013-01-06 16:03:09 +01:00
|
|
|
|
2013-01-01 10:29:53 +01:00
|
|
|
if (sae->state == SAE_COMMITTED && group != sae->group) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Do not allow group to be changed");
|
|
|
|
return WLAN_STATUS_FINITE_CYCLIC_GROUP_NOT_SUPPORTED;
|
|
|
|
}
|
2013-01-06 16:03:09 +01:00
|
|
|
|
2013-01-01 10:29:53 +01:00
|
|
|
if (group != sae->group && sae_set_group(sae, group) < 0) {
|
2012-12-30 21:16:18 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Unsupported Finite Cyclic Group %u",
|
2013-01-01 10:29:53 +01:00
|
|
|
group);
|
2012-12-30 21:16:18 +01:00
|
|
|
return WLAN_STATUS_FINITE_CYCLIC_GROUP_NOT_SUPPORTED;
|
|
|
|
}
|
2013-01-06 16:03:09 +01:00
|
|
|
|
2013-01-05 20:22:00 +01:00
|
|
|
if (sae->dh && !allowed_groups) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Do not allow FFC group %u without "
|
|
|
|
"explicit configuration enabling it", group);
|
|
|
|
return WLAN_STATUS_FINITE_CYCLIC_GROUP_NOT_SUPPORTED;
|
|
|
|
}
|
2012-12-30 21:16:18 +01:00
|
|
|
|
2013-01-06 16:03:09 +01:00
|
|
|
return WLAN_STATUS_SUCCESS;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static void sae_parse_commit_token(struct sae_data *sae, const u8 **pos,
|
|
|
|
const u8 *end, const u8 **token,
|
|
|
|
size_t *token_len)
|
|
|
|
{
|
|
|
|
if (*pos + (sae->ec ? 3 : 2) * sae->prime_len < end) {
|
|
|
|
size_t tlen = end - (*pos + (sae->ec ? 3 : 2) * sae->prime_len);
|
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: Anti-Clogging Token", *pos, tlen);
|
2012-12-31 15:58:36 +01:00
|
|
|
if (token)
|
2013-01-06 16:03:09 +01:00
|
|
|
*token = *pos;
|
2012-12-31 15:58:36 +01:00
|
|
|
if (token_len)
|
|
|
|
*token_len = tlen;
|
2013-01-06 16:03:09 +01:00
|
|
|
*pos += tlen;
|
|
|
|
} else {
|
|
|
|
if (token)
|
|
|
|
*token = NULL;
|
|
|
|
if (token_len)
|
|
|
|
*token_len = 0;
|
2012-12-31 15:58:36 +01:00
|
|
|
}
|
2013-01-06 16:03:09 +01:00
|
|
|
}
|
|
|
|
|
2012-12-31 15:58:36 +01:00
|
|
|
|
2013-01-06 16:03:09 +01:00
|
|
|
static u16 sae_parse_commit_scalar(struct sae_data *sae, const u8 **pos,
|
|
|
|
const u8 *end)
|
|
|
|
{
|
|
|
|
struct crypto_bignum *peer_scalar;
|
|
|
|
|
|
|
|
if (*pos + sae->prime_len > end) {
|
2012-12-30 21:16:18 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Not enough data for scalar");
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
}
|
2012-12-31 10:20:04 +01:00
|
|
|
|
2013-01-06 16:03:09 +01:00
|
|
|
peer_scalar = crypto_bignum_init_set(*pos, sae->prime_len);
|
2013-01-06 15:57:53 +01:00
|
|
|
if (peer_scalar == NULL)
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
|
2012-12-31 10:20:04 +01:00
|
|
|
/*
|
|
|
|
* IEEE Std 802.11-2012, 11.3.8.6.1: If there is a protocol instance for
|
|
|
|
* the peer and it is in Authenticated state, the new Commit Message
|
|
|
|
* shall be dropped if the peer-scalar is identical to the one used in
|
|
|
|
* the existing protocol instance.
|
|
|
|
*/
|
2013-01-06 15:57:53 +01:00
|
|
|
if (sae->state == SAE_ACCEPTED && sae->peer_commit_scalar &&
|
|
|
|
crypto_bignum_cmp(sae->peer_commit_scalar, peer_scalar) == 0) {
|
2012-12-31 10:20:04 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Do not accept re-use of previous "
|
|
|
|
"peer-commit-scalar");
|
2013-01-06 15:57:53 +01:00
|
|
|
crypto_bignum_deinit(peer_scalar, 0);
|
2012-12-31 10:20:04 +01:00
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
}
|
|
|
|
|
2013-01-06 16:34:05 +01:00
|
|
|
/* 0 < scalar < r */
|
|
|
|
if (crypto_bignum_is_zero(peer_scalar) ||
|
|
|
|
crypto_bignum_cmp(peer_scalar, sae->order) >= 0) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Invalid peer scalar");
|
|
|
|
crypto_bignum_deinit(peer_scalar, 0);
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 15:57:53 +01:00
|
|
|
crypto_bignum_deinit(sae->peer_commit_scalar, 0);
|
|
|
|
sae->peer_commit_scalar = peer_scalar;
|
2013-01-06 16:03:09 +01:00
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: Peer commit-scalar", *pos, sae->prime_len);
|
|
|
|
*pos += sae->prime_len;
|
|
|
|
|
|
|
|
return WLAN_STATUS_SUCCESS;
|
|
|
|
}
|
|
|
|
|
2012-12-30 21:16:18 +01:00
|
|
|
|
2013-01-06 16:34:05 +01:00
|
|
|
static u16 sae_parse_commit_element_ecc(struct sae_data *sae, const u8 *pos,
|
|
|
|
const u8 *end)
|
|
|
|
{
|
2013-01-06 17:12:58 +01:00
|
|
|
u8 prime[SAE_MAX_ECC_PRIME_LEN];
|
2013-01-06 16:34:05 +01:00
|
|
|
|
2013-01-01 10:46:02 +01:00
|
|
|
if (pos + 2 * sae->prime_len > end) {
|
2012-12-30 21:16:18 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Not enough data for "
|
|
|
|
"commit-element");
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
}
|
|
|
|
|
2013-01-06 16:34:05 +01:00
|
|
|
if (crypto_bignum_to_bin(sae->prime, prime, sizeof(prime),
|
|
|
|
sae->prime_len) < 0)
|
2013-01-06 17:12:58 +01:00
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
2013-01-06 16:34:05 +01:00
|
|
|
|
|
|
|
/* element x and y coordinates < p */
|
2013-01-06 17:12:58 +01:00
|
|
|
if (os_memcmp(pos, prime, sae->prime_len) >= 0 ||
|
|
|
|
os_memcmp(pos + sae->prime_len + sae->prime_len, prime,
|
2013-01-06 16:34:05 +01:00
|
|
|
sae->prime_len) >= 0) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Invalid coordinates in peer "
|
|
|
|
"element");
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
}
|
|
|
|
|
2013-01-06 17:12:58 +01:00
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: Peer commit-element(x)",
|
|
|
|
pos, sae->prime_len);
|
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: Peer commit-element(y)",
|
|
|
|
pos + sae->prime_len, sae->prime_len);
|
|
|
|
|
|
|
|
crypto_ec_point_deinit(sae->peer_commit_element_ecc, 0);
|
|
|
|
sae->peer_commit_element_ecc = crypto_ec_point_from_bin(sae->ec, pos);
|
|
|
|
if (sae->peer_commit_element_ecc == NULL)
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
|
2012-12-30 21:16:18 +01:00
|
|
|
return WLAN_STATUS_SUCCESS;
|
|
|
|
}
|
2012-12-30 21:28:57 +01:00
|
|
|
|
|
|
|
|
2013-01-06 17:30:11 +01:00
|
|
|
static u16 sae_parse_commit_element_ffc(struct sae_data *sae, const u8 *pos,
|
|
|
|
const u8 *end)
|
|
|
|
{
|
|
|
|
if (pos + sae->prime_len > end) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Not enough data for "
|
|
|
|
"commit-element");
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
}
|
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: Peer commit-element", pos, sae->prime_len);
|
|
|
|
|
|
|
|
crypto_bignum_deinit(sae->peer_commit_element_ffc, 0);
|
|
|
|
sae->peer_commit_element_ffc = crypto_bignum_init_set(pos,
|
|
|
|
sae->prime_len);
|
|
|
|
if (sae->peer_commit_element_ffc == NULL)
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
2013-01-06 17:38:17 +01:00
|
|
|
if (crypto_bignum_is_zero(sae->peer_commit_element_ffc) ||
|
|
|
|
crypto_bignum_is_one(sae->peer_commit_element_ffc) ||
|
|
|
|
crypto_bignum_cmp(sae->peer_commit_element_ffc, sae->prime) >= 0) {
|
2013-01-06 17:30:11 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Invalid peer element");
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
}
|
|
|
|
|
|
|
|
return WLAN_STATUS_SUCCESS;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 16:34:05 +01:00
|
|
|
static u16 sae_parse_commit_element(struct sae_data *sae, const u8 *pos,
|
|
|
|
const u8 *end)
|
|
|
|
{
|
|
|
|
if (sae->dh)
|
|
|
|
return sae_parse_commit_element_ffc(sae, pos, end);
|
|
|
|
return sae_parse_commit_element_ecc(sae, pos, end);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 16:03:09 +01:00
|
|
|
u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
|
|
|
|
const u8 **token, size_t *token_len, int *allowed_groups)
|
|
|
|
{
|
|
|
|
const u8 *pos = data, *end = data + len;
|
|
|
|
u16 res;
|
|
|
|
|
|
|
|
/* Check Finite Cyclic Group */
|
|
|
|
if (pos + 2 > end)
|
|
|
|
return WLAN_STATUS_UNSPECIFIED_FAILURE;
|
|
|
|
res = sae_group_allowed(sae, allowed_groups, WPA_GET_LE16(pos));
|
|
|
|
if (res != WLAN_STATUS_SUCCESS)
|
|
|
|
return res;
|
|
|
|
pos += 2;
|
|
|
|
|
|
|
|
/* Optional Anti-Clogging Token */
|
|
|
|
sae_parse_commit_token(sae, &pos, end, token, token_len);
|
|
|
|
|
|
|
|
/* commit-scalar */
|
|
|
|
res = sae_parse_commit_scalar(sae, &pos, end);
|
|
|
|
if (res != WLAN_STATUS_SUCCESS)
|
|
|
|
return res;
|
|
|
|
|
|
|
|
/* commit-element */
|
|
|
|
return sae_parse_commit_element(sae, pos, end);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 15:57:53 +01:00
|
|
|
static void sae_cn_confirm(struct sae_data *sae, const u8 *sc,
|
|
|
|
const struct crypto_bignum *scalar1,
|
2013-01-06 17:12:58 +01:00
|
|
|
const u8 *element1, size_t element1_len,
|
2013-01-06 15:57:53 +01:00
|
|
|
const struct crypto_bignum *scalar2,
|
2013-01-06 17:12:58 +01:00
|
|
|
const u8 *element2, size_t element2_len,
|
|
|
|
u8 *confirm)
|
2012-12-30 21:28:57 +01:00
|
|
|
{
|
|
|
|
const u8 *addr[5];
|
|
|
|
size_t len[5];
|
2013-01-06 15:57:53 +01:00
|
|
|
u8 scalar_b1[SAE_MAX_PRIME_LEN], scalar_b2[SAE_MAX_PRIME_LEN];
|
2012-12-30 21:28:57 +01:00
|
|
|
|
|
|
|
/* Confirm
|
|
|
|
* CN(key, X, Y, Z, ...) =
|
|
|
|
* HMAC-SHA256(key, D2OS(X) || D2OS(Y) || D2OS(Z) | ...)
|
|
|
|
* confirm = CN(KCK, send-confirm, commit-scalar, COMMIT-ELEMENT,
|
|
|
|
* peer-commit-scalar, PEER-COMMIT-ELEMENT)
|
2013-01-06 15:57:53 +01:00
|
|
|
* verifier = CN(KCK, peer-send-confirm, peer-commit-scalar,
|
|
|
|
* PEER-COMMIT-ELEMENT, commit-scalar, COMMIT-ELEMENT)
|
2012-12-30 21:28:57 +01:00
|
|
|
*/
|
|
|
|
addr[0] = sc;
|
|
|
|
len[0] = 2;
|
2013-01-06 15:57:53 +01:00
|
|
|
crypto_bignum_to_bin(scalar1, scalar_b1, sizeof(scalar_b1),
|
|
|
|
sae->prime_len);
|
|
|
|
addr[1] = scalar_b1;
|
2013-01-01 10:46:02 +01:00
|
|
|
len[1] = sae->prime_len;
|
2013-01-06 15:57:53 +01:00
|
|
|
addr[2] = element1;
|
2013-01-06 17:12:58 +01:00
|
|
|
len[2] = element1_len;
|
2013-01-06 15:57:53 +01:00
|
|
|
crypto_bignum_to_bin(scalar2, scalar_b2, sizeof(scalar_b2),
|
|
|
|
sae->prime_len);
|
|
|
|
addr[3] = scalar_b2;
|
2013-01-01 10:46:02 +01:00
|
|
|
len[3] = sae->prime_len;
|
2013-01-06 15:57:53 +01:00
|
|
|
addr[4] = element2;
|
2013-01-06 17:12:58 +01:00
|
|
|
len[4] = element2_len;
|
2013-01-06 15:57:53 +01:00
|
|
|
hmac_sha256_vector(sae->kck, sizeof(sae->kck), 5, addr, len, confirm);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 17:12:58 +01:00
|
|
|
static void sae_cn_confirm_ecc(struct sae_data *sae, const u8 *sc,
|
|
|
|
const struct crypto_bignum *scalar1,
|
|
|
|
const struct crypto_ec_point *element1,
|
|
|
|
const struct crypto_bignum *scalar2,
|
|
|
|
const struct crypto_ec_point *element2,
|
|
|
|
u8 *confirm)
|
|
|
|
{
|
|
|
|
u8 element_b1[2 * SAE_MAX_ECC_PRIME_LEN];
|
|
|
|
u8 element_b2[2 * SAE_MAX_ECC_PRIME_LEN];
|
|
|
|
|
|
|
|
crypto_ec_point_to_bin(sae->ec, element1, element_b1,
|
|
|
|
element_b1 + sae->prime_len);
|
|
|
|
crypto_ec_point_to_bin(sae->ec, element2, element_b2,
|
|
|
|
element_b2 + sae->prime_len);
|
|
|
|
|
|
|
|
sae_cn_confirm(sae, sc, scalar1, element_b1, 2 * sae->prime_len,
|
|
|
|
scalar2, element_b2, 2 * sae->prime_len, confirm);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static void sae_cn_confirm_ffc(struct sae_data *sae, const u8 *sc,
|
|
|
|
const struct crypto_bignum *scalar1,
|
|
|
|
const struct crypto_bignum *element1,
|
|
|
|
const struct crypto_bignum *scalar2,
|
|
|
|
const struct crypto_bignum *element2,
|
|
|
|
u8 *confirm)
|
|
|
|
{
|
|
|
|
u8 element_b1[SAE_MAX_PRIME_LEN];
|
|
|
|
u8 element_b2[SAE_MAX_PRIME_LEN];
|
|
|
|
|
|
|
|
crypto_bignum_to_bin(element1, element_b1, sizeof(element_b1),
|
|
|
|
sae->prime_len);
|
|
|
|
crypto_bignum_to_bin(element2, element_b2, sizeof(element_b2),
|
|
|
|
sae->prime_len);
|
|
|
|
|
|
|
|
sae_cn_confirm(sae, sc, scalar1, element_b1, sae->prime_len,
|
|
|
|
scalar2, element_b2, sae->prime_len, confirm);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2013-01-06 15:57:53 +01:00
|
|
|
void sae_write_confirm(struct sae_data *sae, struct wpabuf *buf)
|
|
|
|
{
|
|
|
|
const u8 *sc;
|
|
|
|
|
|
|
|
/* Send-Confirm */
|
|
|
|
sc = wpabuf_put(buf, 0);
|
|
|
|
wpabuf_put_le16(buf, sae->send_confirm);
|
|
|
|
sae->send_confirm++;
|
|
|
|
|
2013-01-06 17:12:58 +01:00
|
|
|
if (sae->ec)
|
|
|
|
sae_cn_confirm_ecc(sae, sc, sae->own_commit_scalar,
|
|
|
|
sae->own_commit_element_ecc,
|
|
|
|
sae->peer_commit_scalar,
|
|
|
|
sae->peer_commit_element_ecc,
|
|
|
|
wpabuf_put(buf, SHA256_MAC_LEN));
|
|
|
|
else
|
|
|
|
sae_cn_confirm_ffc(sae, sc, sae->own_commit_scalar,
|
|
|
|
sae->own_commit_element_ffc,
|
|
|
|
sae->peer_commit_scalar,
|
|
|
|
sae->peer_commit_element_ffc,
|
|
|
|
wpabuf_put(buf, SHA256_MAC_LEN));
|
2012-12-30 21:28:57 +01:00
|
|
|
}
|
2012-12-30 21:31:19 +01:00
|
|
|
|
|
|
|
|
|
|
|
int sae_check_confirm(struct sae_data *sae, const u8 *data, size_t len)
|
|
|
|
{
|
|
|
|
u8 verifier[SHA256_MAC_LEN];
|
|
|
|
|
|
|
|
if (len < 2 + SHA256_MAC_LEN) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Too short confirm message");
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
2013-01-06 15:57:53 +01:00
|
|
|
wpa_printf(MSG_DEBUG, "SAE: peer-send-confirm %u", WPA_GET_LE16(data));
|
2012-12-30 21:31:19 +01:00
|
|
|
|
2013-01-06 17:12:58 +01:00
|
|
|
if (sae->ec)
|
|
|
|
sae_cn_confirm_ecc(sae, data, sae->peer_commit_scalar,
|
|
|
|
sae->peer_commit_element_ecc,
|
|
|
|
sae->own_commit_scalar,
|
|
|
|
sae->own_commit_element_ecc,
|
|
|
|
verifier);
|
|
|
|
else
|
|
|
|
sae_cn_confirm_ffc(sae, data, sae->peer_commit_scalar,
|
|
|
|
sae->peer_commit_element_ffc,
|
|
|
|
sae->own_commit_scalar,
|
|
|
|
sae->own_commit_element_ffc,
|
|
|
|
verifier);
|
2012-12-30 21:31:19 +01:00
|
|
|
|
|
|
|
if (os_memcmp(verifier, data + 2, SHA256_MAC_LEN) != 0) {
|
|
|
|
wpa_printf(MSG_DEBUG, "SAE: Confirm mismatch");
|
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: Received confirm",
|
|
|
|
data + 2, SHA256_MAC_LEN);
|
|
|
|
wpa_hexdump(MSG_DEBUG, "SAE: Calculated verifier",
|
|
|
|
verifier, SHA256_MAC_LEN);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|