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sae: update SAE to use ELL API's

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James Prestwood 2019-01-10 11:51:11 -08:00 committed by Denis Kenzior
parent 1d66ee0dd5
commit 48f5a051bc
1 changed files with 190 additions and 231 deletions
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411
src/sae.c
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@ -27,7 +27,6 @@
#include "src/handshake.h" #include "src/handshake.h"
#include "src/crypto.h" #include "src/crypto.h"
#include "src/mpdu.h" #include "src/mpdu.h"
#include "src/ecc.h"
#include "src/sae.h" #include "src/sae.h"
#define SAE_RETRANSMIT_TIMEOUT 2 #define SAE_RETRANSMIT_TIMEOUT 2
@ -42,13 +41,14 @@ enum sae_state {
struct sae_sm { struct sae_sm {
struct handshake_state *handshake; struct handshake_state *handshake;
struct ecc_point pwe; struct l_ecc_point *pwe;
enum sae_state state; enum sae_state state;
uint64_t rand[NUM_ECC_DIGITS]; const struct l_ecc_curve *curve;
uint64_t scalar[NUM_ECC_DIGITS]; struct l_ecc_scalar *rand;
uint64_t p_scalar[NUM_ECC_DIGITS]; struct l_ecc_scalar *scalar;
struct ecc_point element; struct l_ecc_scalar *p_scalar;
struct ecc_point p_element; struct l_ecc_point *element;
struct l_ecc_point *p_element;
uint16_t send_confirm; uint16_t send_confirm;
uint8_t kck[32]; uint8_t kck[32];
uint8_t pmk[32]; uint8_t pmk[32];
@ -69,60 +69,6 @@ struct sae_sm {
void *user_data; void *user_data;
}; };
static uint64_t curve_p[NUM_ECC_DIGITS] = CURVE_P_32;
static uint64_t curve_n[NUM_ECC_DIGITS] = CURVE_N_32;
/* calculate random quadratic residue */
static void sae_get_qr(uint64_t *qr)
{
l_getrandom(qr, 32);
while (vli_legendre(qr, curve_p) != -1)
l_getrandom(qr, 32);
}
/* calculate random quadratic non-residue */
static void sae_get_qnr(uint64_t *qnr)
{
l_getrandom(qnr, 32);
while (vli_legendre(qnr, curve_p) != 1)
l_getrandom(qnr, 32);
}
/* blinding technique to determine if 'value' is quadratic residue */
static bool sae_is_quadratic_residue(uint64_t *value, uint64_t *qr,
uint64_t *qnr)
{
uint64_t y_sqr[NUM_ECC_DIGITS];
uint64_t r[NUM_ECC_DIGITS];
uint64_t num[NUM_ECC_DIGITS];
ecc_compute_y_sqr(y_sqr, value);
l_getrandom(r, 32);
while (vli_cmp(r, curve_p) >= 0)
l_getrandom(r, 32);
vli_mod_mult_fast(num, y_sqr, r);
vli_mod_mult_fast(num, num, r);
if (r[0] & 1) {
vli_mod_mult_fast(num, num, qr);
if (vli_legendre(num, curve_p) == -1)
return true;
} else {
vli_mod_mult_fast(num, num, qnr);
if (vli_legendre(num, curve_p) == 1)
return true;
}
return false;
}
static bool sae_pwd_seed(const uint8_t *addr1, const uint8_t *addr2, static bool sae_pwd_seed(const uint8_t *addr1, const uint8_t *addr2,
uint8_t *base, size_t base_len, uint8_t *base, size_t base_len,
uint8_t counter, uint8_t *out) uint8_t counter, uint8_t *out)
@ -141,25 +87,38 @@ static bool sae_pwd_seed(const uint8_t *addr1, const uint8_t *addr2,
&counter, 1); &counter, 1);
} }
static bool sae_pwd_value(uint8_t *pwd_seed, uint64_t *pwd_value) static struct l_ecc_scalar *sae_pwd_value(const struct l_ecc_curve *curve,
uint8_t *pwd_seed)
{ {
uint64_t prime[NUM_ECC_DIGITS]; uint8_t pwd_value[L_ECC_SCALAR_MAX_BYTES];
uint8_t prime[L_ECC_SCALAR_MAX_BYTES];
ssize_t len;
struct l_ecc_scalar *p = l_ecc_curve_get_prime(curve);
memcpy(prime, curve_p, 32); len = l_ecc_scalar_get_data(p, prime, sizeof(prime));
ecc_be2native(prime); l_ecc_scalar_free(p);
return kdf_sha256(pwd_seed, 32, "SAE Hunting and Pecking", if (!kdf_sha256(pwd_seed, 32, "SAE Hunting and Pecking",
strlen("SAE Hunting and Pecking"), prime, 32, strlen("SAE Hunting and Pecking"), prime, len,
pwd_value, 32); pwd_value, 32))
return false;
return l_ecc_scalar_new(curve, pwd_value, sizeof(pwd_value));
} }
/* IEEE 802.11-2016 - Section 12.4.2 Assumptions on SAE */ /* IEEE 802.11-2016 - Section 12.4.2 Assumptions on SAE */
static bool sae_cn(const uint8_t *kck, uint16_t send_confirm, static bool sae_cn(const uint8_t *kck, uint16_t send_confirm,
const uint64_t *scalar1, const uint64_t *element1, struct l_ecc_scalar *scalar1,
const uint64_t *scalar2, const uint64_t *element2, struct l_ecc_point *element1,
struct l_ecc_scalar *scalar2,
struct l_ecc_point *element2,
uint8_t *confirm) uint8_t *confirm)
{ {
uint8_t s1[L_ECC_SCALAR_MAX_BYTES];
uint8_t s2[L_ECC_SCALAR_MAX_BYTES];
uint8_t e1[L_ECC_POINT_MAX_BYTES];
uint8_t e2[L_ECC_POINT_MAX_BYTES];
struct l_checksum *hmac; struct l_checksum *hmac;
struct iovec iov[5]; struct iovec iov[5];
int ret; int ret;
@ -170,14 +129,14 @@ static bool sae_cn(const uint8_t *kck, uint16_t send_confirm,
iov[0].iov_base = &send_confirm; iov[0].iov_base = &send_confirm;
iov[0].iov_len = 2; iov[0].iov_len = 2;
iov[1].iov_base = (void *) scalar1; iov[1].iov_base = (void *) s1;
iov[1].iov_len = 32; iov[1].iov_len = l_ecc_scalar_get_data(scalar1, s1, sizeof(s1));
iov[2].iov_base = (void *) element1; iov[2].iov_base = (void *) e1;
iov[2].iov_len = 64; iov[2].iov_len = l_ecc_point_get_data(element1, e1, sizeof(e1));
iov[3].iov_base = (void *) scalar2; iov[3].iov_base = (void *) s2;
iov[3].iov_len = 32; iov[3].iov_len = l_ecc_scalar_get_data(scalar2, s2, sizeof(s2));;
iov[4].iov_base = (void *) element2; iov[4].iov_base = (void *) e2;
iov[4].iov_len = 64; iov[4].iov_len = l_ecc_point_get_data(element2, e2, sizeof(e2));;
l_checksum_updatev(hmac, iov, 5); l_checksum_updatev(hmac, iov, 5);
@ -217,28 +176,89 @@ static void sae_reject_authentication(struct sae_sm *sm, uint16_t reason)
sae_authentication_failed(sm, reason); sae_authentication_failed(sm, reason);
} }
static struct l_ecc_scalar *sae_new_residue(const struct l_ecc_curve *curve,
bool residue)
{
struct l_ecc_scalar *s = l_ecc_scalar_new_random(curve);
while (l_ecc_scalar_legendre(s) != ((residue) ? -1 : 1)) {
l_ecc_scalar_free(s);
s = l_ecc_scalar_new_random(curve);
}
return s;
}
static bool sae_is_quadradic_residue(const struct l_ecc_curve *curve,
struct l_ecc_scalar *value,
struct l_ecc_scalar *qr,
struct l_ecc_scalar *qnr)
{
uint64_t rbuf[L_ECC_MAX_DIGITS];
struct l_ecc_scalar *y_sqr = l_ecc_scalar_new(curve, NULL, 0);
struct l_ecc_scalar *r = l_ecc_scalar_new_random(curve);
struct l_ecc_scalar *num = l_ecc_scalar_new(curve, NULL, 0);
size_t bytes;
l_ecc_scalar_sum_x(y_sqr, value);
l_ecc_scalar_multiply(num, y_sqr, r);
l_ecc_scalar_multiply(num, num, r);
l_ecc_scalar_free(y_sqr);
bytes = l_ecc_scalar_get_data(r, rbuf, sizeof(rbuf));
l_ecc_scalar_free(r);
if (bytes <= 0) {
l_ecc_scalar_free(num);
return false;
}
if (rbuf[bytes / 8] & 1) {
l_ecc_scalar_multiply(num, num, qr);
if (l_ecc_scalar_legendre(num) == -1) {
l_ecc_scalar_free(num);
return true;
}
} else {
l_ecc_scalar_multiply(num, num, qnr);
if (l_ecc_scalar_legendre(num) == 1) {
l_ecc_scalar_free(num);
return true;
}
}
l_ecc_scalar_free(num);
return false;
}
/* /*
* IEEE 802.11-2016 Section 12.4.4.2.2 * IEEE 802.11-2016 Section 12.4.4.2.2
* Generation of the password element with ECC groups * Generation of the password element with ECC groups
*/ */
static bool sae_compute_pwe(char *password, const uint8_t *addr1, static bool sae_compute_pwe(struct sae_sm *sm, char *password,
const uint8_t *addr2, struct ecc_point *pwe) const uint8_t *addr1, const uint8_t *addr2)
{ {
bool found = false; bool found = false;
uint8_t counter = 1; uint8_t counter = 1;
uint8_t k = 20; uint8_t k = 20;
uint8_t pwd_seed[32]; uint8_t pwd_seed[32];
uint64_t pwd_value[NUM_ECC_DIGITS]; struct l_ecc_scalar *pwd_value;
uint8_t random[32]; uint8_t random[32];
uint8_t *base = (uint8_t *) password; uint8_t *base = (uint8_t *) password;
size_t base_len = strlen(password); size_t base_len = strlen(password);
uint8_t save[32] = { 0 }; uint8_t save[32] = { 0 };
uint64_t qr[NUM_ECC_DIGITS]; struct l_ecc_scalar *qr;
uint64_t qnr[NUM_ECC_DIGITS]; struct l_ecc_scalar *qnr;
uint8_t x[L_ECC_SCALAR_MAX_BYTES];
/* create qr/qnr prior to beginning hunting-and-pecking loop */ /* create qr/qnr prior to beginning hunting-and-pecking loop */
sae_get_qr(qr); qr = sae_new_residue(sm->curve, true);
sae_get_qnr(qnr); qnr = sae_new_residue(sm->curve, false);
do { do {
/* pwd-seed = H(max(addr1, addr2) || min(addr1, addr2), /* pwd-seed = H(max(addr1, addr2) || min(addr1, addr2),
@ -247,15 +267,12 @@ static bool sae_compute_pwe(char *password, const uint8_t *addr1,
*/ */
sae_pwd_seed(addr1, addr2, base, base_len, counter, pwd_seed); sae_pwd_seed(addr1, addr2, base, base_len, counter, pwd_seed);
sae_pwd_value(pwd_seed, pwd_value); pwd_value = sae_pwd_value(sm->curve, pwd_seed);
ecc_be2native(pwd_value); if (sae_is_quadradic_residue(sm->curve, pwd_value, qr, qnr)) {
/* if (pwd-value < p) { */
if (vli_cmp(pwd_value, curve_p) < 0) {
if (sae_is_quadratic_residue(pwd_value, qr, qnr)) {
if (found == false) { if (found == false) {
memcpy(pwe->x, pwd_value, 32); l_ecc_scalar_get_data(pwd_value, x, sizeof(x));
memcpy(save, pwd_seed, 32); memcpy(save, pwd_seed, 32);
l_getrandom(random, 32); l_getrandom(random, 32);
@ -265,69 +282,35 @@ static bool sae_compute_pwe(char *password, const uint8_t *addr1,
found = true; found = true;
} }
} }
}
l_ecc_scalar_free(pwd_value);
counter++; counter++;
} while ((counter <= k) || (found == false)); } while ((counter <= k) || (found == false));
l_ecc_scalar_free(qr);
l_ecc_scalar_free(qnr);
if (!found) { if (!found) {
l_error("max PWE iterations reached!"); l_error("max PWE iterations reached!");
return false; return false;
} }
if (!ecc_compute_y(pwe->y, pwe->x)) { if (!(save[31] & 1))
/* should always return true */ sm->pwe = l_ecc_point_from_data(sm->curve,
L_ECC_POINT_TYPE_COMPRESSED_BIT1,
x, sizeof(x));
else
sm->pwe = l_ecc_point_from_data(sm->curve,
L_ECC_POINT_TYPE_COMPRESSED_BIT0,
x, sizeof(x));
if (!sm->pwe) {
l_error("computing y failed, was x quadratic residue?"); l_error("computing y failed, was x quadratic residue?");
return false; return false;
} }
if ((pwe->y[0] & 1) != (save[31] & 1))
vli_mod_sub(pwe->y, curve_p, pwe->y, curve_p);
return true;
}
/* commit-scalar = (rand + mask) mod r */
static void sae_get_commit_scalar(uint64_t *scalar, uint64_t *mask,
uint64_t *rand)
{
uint64_t _1[NUM_ECC_DIGITS] = { 1ull };
l_getrandom(rand, ECC_BYTES);
/* ensure 1 < p_rand < r */
while (!((vli_cmp(rand, _1) > 0) &&
(vli_cmp(rand, curve_n) < 0)))
l_getrandom(rand, ECC_BYTES);
l_getrandom(mask, ECC_BYTES);
/* ensure 1 < p_mask < r */
while (!((vli_cmp(mask, _1) > 0) &&
(vli_cmp(mask, curve_n) < 0)))
l_getrandom(mask, ECC_BYTES);
/* (rand + mask) mod r */
vli_mod_add(scalar, rand, mask, curve_n);
}
/* commit-element = inv(mask * PWE) */
static bool sae_get_commit_element(struct ecc_point *element,
struct ecc_point *pwe, uint64_t *mask)
{
/* p_mask * PWE */
ecc_point_mult(element, pwe, mask, NULL, vli_num_bits(mask));
if (!ecc_valid_point(element))
return false;
/* inv(p_mask * PWE) */
vli_sub(element->y, curve_p, element->y);
if (!ecc_valid_point(element))
return false;
return true; return true;
} }
@ -335,10 +318,9 @@ static bool sae_build_commit(struct sae_sm *sm, const uint8_t *addr1,
const uint8_t *addr2, uint8_t *commit, const uint8_t *addr2, uint8_t *commit,
size_t *len, bool retry) size_t *len, bool retry)
{ {
uint64_t scalar[NUM_ECC_DIGITS]; struct l_ecc_scalar *mask;
uint64_t mask[NUM_ECC_DIGITS];
struct ecc_point element;
uint8_t *ptr = commit; uint8_t *ptr = commit;
struct l_ecc_scalar *order;
if (retry) if (retry)
goto old_commit; goto old_commit;
@ -348,18 +330,28 @@ static bool sae_build_commit(struct sae_sm *sm, const uint8_t *addr1,
return false; return false;
} }
if (!sae_compute_pwe(sm->handshake->passphrase, addr1, if (!sae_compute_pwe(sm, sm->handshake->passphrase, addr1, addr2)) {
addr2, &sm->pwe)) {
l_error("could not compute PWE"); l_error("could not compute PWE");
return false; return false;
} }
sae_get_commit_scalar(sm->scalar, mask, sm->rand); sm->scalar = l_ecc_scalar_new(sm->curve, NULL, 0);
sm->rand = l_ecc_scalar_new_random(sm->curve);
mask = l_ecc_scalar_new_random(sm->curve);
if (!sae_get_commit_element(&sm->element, &sm->pwe, mask)) { order = l_ecc_curve_get_order(sm->curve);
l_error("error calculating commit element");
return false; /* commit-scalar = (rand + mask) mod r */
} l_ecc_scalar_add(sm->scalar, sm->rand, mask, order);
l_ecc_scalar_free(order);
/* commit-element = inv(mask * PWE) */
sm->element = l_ecc_point_new(sm->curve);
l_ecc_point_multiply(sm->element, mask, sm->pwe);
l_ecc_point_inverse(sm->element);
l_ecc_scalar_free(mask);
/* /*
* Several cases require retransmitting the same commit message. The * Several cases require retransmitting the same commit message. The
@ -367,13 +359,6 @@ static bool sae_build_commit(struct sae_sm *sm, const uint8_t *addr1,
* timeout. * timeout.
*/ */
old_commit: old_commit:
memcpy(scalar, sm->scalar, 32);
memcpy(element.x, sm->element.x, 32);
memcpy(element.y, sm->element.y, 32);
ecc_native2be(scalar);
ecc_native2be(element.x);
ecc_native2be(element.y);
/* transaction */ /* transaction */
l_put_le16(1, ptr); l_put_le16(1, ptr);
@ -390,12 +375,8 @@ old_commit:
ptr += sm->token_len; ptr += sm->token_len;
} }
memcpy(ptr, scalar, 32); ptr += l_ecc_scalar_get_data(sm->scalar, ptr, L_ECC_SCALAR_MAX_BYTES);
ptr += 32; ptr += l_ecc_point_get_data(sm->element, ptr, L_ECC_POINT_MAX_BYTES);
memcpy(ptr, element.x, 32);
ptr += 32;
memcpy(ptr, element.y, 32);
ptr += 32;
*len = ptr - commit; *len = ptr - commit;
@ -408,30 +389,12 @@ static void sae_send_confirm(struct sae_sm *sm)
uint8_t body[38]; uint8_t body[38];
uint8_t *ptr = body; uint8_t *ptr = body;
ecc_native2be(sm->scalar);
ecc_native2be(sm->element.x);
ecc_native2be(sm->element.y);
ecc_native2be(sm->p_scalar);
ecc_native2be(sm->p_element.x);
ecc_native2be(sm->p_element.y);
/* /*
* confirm = CN(KCK, send-confirm, commit-scalar, COMMIT-ELEMENT, * confirm = CN(KCK, send-confirm, commit-scalar, COMMIT-ELEMENT,
* peer-commit-scalar, PEER-COMMIT-ELEMENT) * peer-commit-scalar, PEER-COMMIT-ELEMENT)
*/ */
sae_cn(sm->kck, sm->sc, sm->scalar, (uint64_t *) &sm->element, sae_cn(sm->kck, sm->sc, sm->scalar, sm->element, sm->p_scalar,
sm->p_scalar, (uint64_t *) &sm->p_element, confirm); sm->p_element, confirm);
/*
* in case of retransmition, we will need to reuse these values, so
* go back to native endianness for consistency.
*/
ecc_be2native(sm->scalar);
ecc_be2native(sm->element.x);
ecc_be2native(sm->element.y);
ecc_be2native(sm->p_scalar);
ecc_be2native(sm->p_element.x);
ecc_be2native(sm->p_element.y);
l_put_le16(2, ptr); l_put_le16(2, ptr);
ptr += 2; ptr += 2;
@ -451,14 +414,17 @@ static void sae_process_commit(struct sae_sm *sm, const uint8_t *from,
const uint8_t *frame, size_t len) const uint8_t *frame, size_t len)
{ {
uint8_t *ptr = (uint8_t *) frame; uint8_t *ptr = (uint8_t *) frame;
uint64_t k[NUM_ECC_DIGITS]; uint8_t k[L_ECC_SCALAR_MAX_BYTES];
struct ecc_point k_point; struct l_ecc_point *k_point;
uint8_t zero_key[32] = { 0 }; uint8_t zero_key[32] = { 0 };
uint8_t keyseed[32]; uint8_t keyseed[32];
uint8_t kck_and_pmk[2][32]; uint8_t kck_and_pmk[2][32];
uint64_t tmp[NUM_ECC_DIGITS]; uint8_t tmp[L_ECC_SCALAR_MAX_BYTES];
struct l_ecc_scalar *tmp_scalar;
uint16_t group; uint16_t group;
uint16_t reason = MMPDU_REASON_CODE_UNSPECIFIED; uint16_t reason = MMPDU_REASON_CODE_UNSPECIFIED;
ssize_t klen;
struct l_ecc_scalar *order;
if (sm->state != SAE_STATE_COMMITTED) { if (sm->state != SAE_STATE_COMMITTED) {
l_error("bad state %u", sm->state); l_error("bad state %u", sm->state);
@ -479,19 +445,14 @@ static void sae_process_commit(struct sae_sm *sm, const uint8_t *from,
goto reject; goto reject;
} }
memcpy(sm->p_scalar, ptr, 32); sm->p_scalar = l_ecc_scalar_new(sm->curve, ptr, 32);
ptr += 32; ptr += 32;
memcpy(sm->p_element.x, ptr, 32);
ptr += 32;
memcpy(sm->p_element.y, ptr, 32);
ecc_be2native(sm->p_scalar); sm->p_element = l_ecc_point_from_data(sm->curve, L_ECC_POINT_TYPE_FULL,
ecc_be2native(sm->p_element.x); ptr, 64);
ecc_be2native(sm->p_element.y);
if (!memcmp(sm->p_scalar, sm->scalar, 32) || if (l_ecc_scalars_are_equal(sm->p_scalar, sm->scalar) ||
!memcmp(sm->p_element.x, sm->element.x, 32) || l_ecc_points_are_equal(sm->p_element, sm->element)) {
!memcmp(sm->p_element.y, sm->element.y, 32)) {
/* possible reflection attack, silently discard message */ /* possible reflection attack, silently discard message */
l_warn("peer scalar or element matched own, discarding frame"); l_warn("peer scalar or element matched own, discarding frame");
@ -504,17 +465,16 @@ static void sae_process_commit(struct sae_sm *sm, const uint8_t *from,
* K = scalar-op(rand, (element-op(scalar-op(peer-commit-scalar, PWE), * K = scalar-op(rand, (element-op(scalar-op(peer-commit-scalar, PWE),
* PEER-COMMIT-ELEMENT))) * PEER-COMMIT-ELEMENT)))
*/ */
k_point = l_ecc_point_new(sm->curve);
/* k_point = scalar-op(peer-commit-scalar, PWE) */ /* k_point = scalar-op(peer-commit-scalar, PWE) */
ecc_point_mult(&k_point, &sm->pwe, sm->p_scalar, NULL, l_ecc_point_multiply(k_point, sm->p_scalar, sm->pwe);
vli_num_bits(sm->p_scalar));
/* k_point = element-op(k_point, PEER-COMMIT-ELEMENT) */ /* k_point = element-op(k_point, PEER-COMMIT-ELEMENT) */
ecc_point_add(&k_point, &k_point, &sm->p_element); l_ecc_point_add(k_point, k_point, sm->p_element);
/* k_point = scalar-op(rand, k_point) */ /* k_point = scalar-op(rand, k_point) */
ecc_point_mult(&k_point, &k_point, sm->rand, NULL, l_ecc_point_multiply(k_point, sm->rand, k_point);
vli_num_bits(sm->rand));
/* /*
* IEEE 802.11-2016 - Section 12.4.4.2.1 ECC group definition * IEEE 802.11-2016 - Section 12.4.4.2.1 ECC group definition
@ -522,20 +482,22 @@ static void sae_process_commit(struct sae_sm *sm, const uint8_t *from,
* point (x, y) that satisfies the curve equation to its x-coordinate— * point (x, y) that satisfies the curve equation to its x-coordinate—
* i.e., if P = (x, y) then F(P) = x. * i.e., if P = (x, y) then F(P) = x.
*/ */
memcpy(k, k_point.x, 32); klen = l_ecc_point_get_x(k_point, k, sizeof(k));
ecc_native2be(k); l_ecc_point_free(k_point);
/* keyseed = H(<0>32, k) */ /* keyseed = H(<0>32, k) */
hmac_sha256(zero_key, 32, k, 32, keyseed, 32); hmac_sha256(zero_key, 32, k, klen, keyseed, 32);
/* /*
* kck_and_pmk = KDF-Hash-512(keyseed, "SAE KCK and PMK", * kck_and_pmk = KDF-Hash-512(keyseed, "SAE KCK and PMK",
(commit-scalar + peer-commit-scalar) mod r) (commit-scalar + peer-commit-scalar) mod r)
*/ */
vli_mod_add(tmp, sm->p_scalar, sm->scalar, curve_n); tmp_scalar = l_ecc_scalar_new(sm->curve, NULL, 0);
order = l_ecc_curve_get_order(sm->curve);
ecc_native2be(tmp); l_ecc_scalar_add(tmp_scalar, sm->p_scalar, sm->scalar, order);
l_ecc_scalar_get_data(tmp_scalar, tmp, sizeof(tmp));
kdf_sha256(keyseed, 32, "SAE KCK and PMK", strlen("SAE KCK and PMK"), kdf_sha256(keyseed, 32, "SAE KCK and PMK", strlen("SAE KCK and PMK"),
tmp, 32, kck_and_pmk, 64); tmp, 32, kck_and_pmk, 64);
@ -546,8 +508,12 @@ static void sae_process_commit(struct sae_sm *sm, const uint8_t *from,
/* /*
* PMKID = L((commit-scalar + peer-commit-scalar) mod r, 0, 128) * PMKID = L((commit-scalar + peer-commit-scalar) mod r, 0, 128)
*/ */
vli_mod_add(tmp, sm->scalar, sm->p_scalar, curve_n); l_ecc_scalar_add(tmp_scalar, sm->scalar, sm->p_scalar, order);
ecc_native2be(tmp); l_ecc_scalar_get_data(tmp_scalar, tmp, sizeof(tmp));
l_ecc_scalar_free(order);
l_ecc_scalar_free(tmp_scalar);
/* don't set the handshakes pmkid until confirm is verified */ /* don't set the handshakes pmkid until confirm is verified */
memcpy(sm->pmkid, tmp, 16); memcpy(sm->pmkid, tmp, 16);
@ -564,23 +530,8 @@ static bool sae_verify_confirm(struct sae_sm *sm, const uint8_t *frame)
uint8_t check[32]; uint8_t check[32];
uint16_t rc = l_get_le16(frame); uint16_t rc = l_get_le16(frame);
ecc_native2be(sm->scalar); sae_cn(sm->kck, rc, sm->p_scalar, sm->p_element, sm->scalar,
ecc_native2be(sm->element.x); sm->element, check);
ecc_native2be(sm->element.y);
ecc_native2be(sm->p_scalar);
ecc_native2be(sm->p_element.x);
ecc_native2be(sm->p_element.y);
sae_cn(sm->kck, rc, sm->p_scalar,
(const uint64_t *) &sm->p_element, sm->scalar,
(const uint64_t *) &sm->element, check);
ecc_be2native(sm->scalar);
ecc_be2native(sm->element.x);
ecc_be2native(sm->element.y);
ecc_be2native(sm->p_scalar);
ecc_be2native(sm->p_element.x);
ecc_be2native(sm->p_element.y);
if (memcmp(frame + 2, check, 32)) { if (memcmp(frame + 2, check, 32)) {
l_error("confirm did not match"); l_error("confirm did not match");
@ -978,6 +929,7 @@ struct sae_sm *sae_sm_new(struct handshake_state *hs, sae_tx_packet_func_t tx,
sm->user_data = user_data; sm->user_data = user_data;
sm->handshake = hs; sm->handshake = hs;
sm->state = SAE_STATE_NOTHING; sm->state = SAE_STATE_NOTHING;
sm->curve = l_ecc_curve_get(19);
return sm; return sm;
} }
@ -986,6 +938,13 @@ void sae_sm_free(struct sae_sm *sm)
{ {
l_free(sm->token); l_free(sm->token);
l_ecc_scalar_free(sm->scalar);
l_ecc_scalar_free(sm->p_scalar);
l_ecc_scalar_free(sm->rand);
l_ecc_point_free(sm->element);
l_ecc_point_free(sm->p_element);
l_ecc_point_free(sm->pwe);
/* zero out whole structure, including keys */ /* zero out whole structure, including keys */
memset(sm, 0, sizeof(struct sae_sm)); memset(sm, 0, sizeof(struct sae_sm));