void ep_tab(ep_t *t, const ep_t p, int w) {
if (w > 2) {
ep_dbl(t[0], p);
#if defined(EP_MIXED)
ep_norm(t[0], t[0]);
#endif
ep_add(t[1], t[0], p);
for (int i = 2; i < (1 << (w - 2)); i++) {
ep_add(t[i], t[i - 1], t[0]);
}
#if defined(EP_MIXED)
ep_norm_sim(t + 1, (const ep_t *)t + 1, (1 << (w - 2)) - 1);
#endif
}
ep_copy(t[0], p);
}
void ep_mul_sim_basic(ep_t r, const ep_t p, const bn_t k, const ep_t q,
const bn_t m) {
ep_t t;
ep_null(t);
TRY {
ep_new(t);
ep_mul(t, q, m);
ep_mul(r, p, k);
ep_add(t, t, r);
ep_norm(r, t);
} CATCH_ANY {
THROW(ERR_CAUGHT);
}
FINALLY {
ep_free(t);
}
}
int main(int argc, char **argv) {
struct sockaddr_in config, peer;
struct epoll_event ev, events[EP_SIZE];
struct conn_status status[MAX_FD], *curr;
in_port_t port = L_PORT;
int listenfd, epfd, connfd;
int i, flag, nfds, current_fd;
socklen_t len;
char buffer[FILE_BUFFER];
// init
sockinit(&config);
sockset(&config, port, NULL);
memset(status, 0, sizeof(status));
memset(buffer, 0, sizeof(buffer));
signal(SIGPIPE, SIG_IGN);
// create server
listenfd = create_server(&config);
if (listenfd < 0) {
perror("xtrans: server create failed.");
exit(EXIT_FAILURE);
}
// create epoll fd
epfd = ep_ini();
if (epfd < 0) {
perror("xtrans: epoll init failed.");
exit(EXIT_FAILURE);
}
// add listen fd to epoll
ev.events = EPOLLIN;
ev.data.fd = listenfd;
if (ep_add(epfd, listenfd, &ev) == -1) {
perror("xtrans: add epoll event failed.");
exit(EXIT_FAILURE);
}
// main loop
for(;;) {
nfds = ep_col(epfd, events);
for (i = 0; i < nfds; i++) {
current_fd = events[i].data.fd;
if (current_fd == listenfd) {
connfd = accept(listenfd, (SA *)&peer, &len);
if (connfd == -1) {
continue;
}
memcpy(&(status[connfd].client), &peer, sizeof(struct sockaddr_in));
ev.events = EPOLLIN;
ev.data.fd = connfd;
if (ep_add(epfd, connfd, &ev) == -1) {
continue;
}
flag = welcome(connfd, &(status[connfd]));
if (flag >= 0) {
x_log(LOG_CONN, &(status[connfd]));
} else {
x_log(LOG_DISC, &(status[connfd]));
terminate(epfd, connfd, &(status[connfd]));
}
} else if (events[i].events & EPOLLIN) {
curr = &(status[current_fd]);
switch (curr->status) {
case STATUS_INIT:
memset(&(curr->username), 0, sizeof(char)*12);
flag = readln(current_fd, curr->username, 1);
if (flag < 0) {
terminate(epfd, current_fd, curr);
x_log(LOG_DISC, curr);
}
flag = get_username(current_fd, curr);
if (flag < 0) {
terminate(epfd, current_fd, curr);
x_log(LOG_DISC, curr);
}
break;
case STATUS_NAME:
memset(&(curr->passwd), 0, sizeof(char)*32);
flag = readln(current_fd, curr->passwd, 1);
if (flag < 0) {
terminate(epfd, current_fd, curr);
x_log(LOG_DISC, curr);
}
flag = get_passwd(current_fd, curr);
if (flag < 0) {
terminate(epfd, current_fd, curr);
x_log(LOG_DISC, curr);
}
flag = auth(curr->username, curr->passwd);
if (flag < 0) {
flag = auth_failed(current_fd, curr);
terminate(epfd, current_fd, curr);
x_log(LOG_REFS, curr);
} else {
flag = auth_success(current_fd, curr);
if (flag < 0) {
x_log(LOG_DISC, curr);
} else {
x_log(LOG_LOGI, curr);
}
}
break;
case STATUS_SUCC:
flag = readFd(current_fd, buffer, 1024);
if (flag < 0) {
terminate(epfd, current_fd, curr);
x_log(LOG_DISC, curr);
}
curr->recvb = flag;
terminate(epfd, current_fd, curr);
x_log(LOG_FINS, curr);
break;
default:
perror("xtrans: status not define, default action triggered.");
terminate(epfd, current_fd, curr);
}
}
}
}
return 0;
}
/**
* Multiplies and adds two prime elliptic curve points simultaneously,
* optionally choosing the first point as the generator depending on an optional
* table of precomputed points.
*
* @param[out] r - the result.
* @param[in] p - the first point to multiply.
* @param[in] k - the first integer.
* @param[in] q - the second point to multiply.
* @param[in] m - the second integer.
* @param[in] t - the pointer to the precomputed table.
*/
void ep_mul_sim_endom(ep_t r, const ep_t p, const bn_t k, const ep_t q,
const bn_t m, const ep_t *t) {
int len, len0, len1, len2, len3, i, n, sk0, sk1, sl0, sl1, w, g = 0;
int8_t naf0[FP_BITS + 1], naf1[FP_BITS + 1], *t0, *t1;
int8_t naf2[FP_BITS + 1], naf3[FP_BITS + 1], *t2, *t3;
bn_t k0, k1, l0, l1;
bn_t ord, v1[3], v2[3];
ep_t u;
ep_t tab0[1 << (EP_WIDTH - 2)];
ep_t tab1[1 << (EP_WIDTH - 2)];
bn_null(ord);
bn_null(k0);
bn_null(k1);
bn_null(l0);
bn_null(l1);
ep_null(u);
for (i = 0; i < (1 << (EP_WIDTH - 2)); i++) {
ep_null(tab0[i]);
ep_null(tab1[i]);
}
bn_new(ord);
bn_new(k0);
bn_new(k1);
bn_new(l0);
bn_new(l1);
ep_new(u);
TRY {
for (i = 0; i < 3; i++) {
bn_null(v1[i]);
bn_null(v2[i]);
bn_new(v1[i]);
bn_new(v2[i]);
}
ep_curve_get_ord(ord);
ep_curve_get_v1(v1);
ep_curve_get_v2(v2);
bn_rec_glv(k0, k1, k, ord, (const bn_t *)v1, (const bn_t *)v2);
sk0 = bn_sign(k0);
sk1 = bn_sign(k1);
bn_abs(k0, k0);
bn_abs(k1, k1);
bn_rec_glv(l0, l1, m, ord, (const bn_t *)v1, (const bn_t *)v2);
sl0 = bn_sign(l0);
sl1 = bn_sign(l1);
bn_abs(l0, l0);
bn_abs(l1, l1);
g = (t == NULL ? 0 : 1);
if (!g) {
for (i = 0; i < (1 << (EP_WIDTH - 2)); i++) {
ep_new(tab0[i]);
}
ep_tab(tab0, p, EP_WIDTH);
t = (const ep_t *)tab0;
}
/* Prepare the precomputation table. */
for (i = 0; i < (1 << (EP_WIDTH - 2)); i++) {
ep_new(tab1[i]);
}
/* Compute the precomputation table. */
ep_tab(tab1, q, EP_WIDTH);
/* Compute the w-TNAF representation of k and l */
if (g) {
w = EP_DEPTH;
} else {
w = EP_WIDTH;
}
len0 = len1 = len2 = len3 = FP_BITS + 1;
bn_rec_naf(naf0, &len0, k0, w);
bn_rec_naf(naf1, &len1, k1, w);
bn_rec_naf(naf2, &len2, l0, EP_WIDTH);
bn_rec_naf(naf3, &len3, l1, EP_WIDTH);
len = MAX(MAX(len0, len1), MAX(len2, len3));
t0 = naf0 + len - 1;
t1 = naf1 + len - 1;
t2 = naf2 + len - 1;
t3 = naf3 + len - 1;
for (i = len0; i < len; i++) {
naf0[i] = 0;
}
for (i = len1; i < len; i++) {
naf1[i] = 0;
}
for (i = len2; i < len; i++) {
naf2[i] = 0;
}
for (i = len3; i < len; i++) {
naf3[i] = 0;
}
ep_set_infty(r);
for (i = len - 1; i >= 0; i--, t0--, t1--, t2--, t3--) {
ep_dbl(r, r);
n = *t0;
if (n > 0) {
if (sk0 == BN_POS) {
ep_add(r, r, t[n / 2]);
} else {
ep_sub(r, r, t[n / 2]);
}
}
if (n < 0) {
if (sk0 == BN_POS) {
ep_sub(r, r, t[-n / 2]);
} else {
ep_add(r, r, t[-n / 2]);
}
}
n = *t1;
if (n > 0) {
ep_copy(u, t[n / 2]);
fp_mul(u->x, u->x, ep_curve_get_beta());
if (sk1 == BN_NEG) {
ep_neg(u, u);
}
ep_add(r, r, u);
}
if (n < 0) {
ep_copy(u, t[-n / 2]);
fp_mul(u->x, u->x, ep_curve_get_beta());
if (sk1 == BN_NEG) {
ep_neg(u, u);
}
ep_sub(r, r, u);
}
n = *t2;
if (n > 0) {
if (sl0 == BN_POS) {
ep_add(r, r, tab1[n / 2]);
} else {
ep_sub(r, r, tab1[n / 2]);
}
}
if (n < 0) {
if (sl0 == BN_POS) {
ep_sub(r, r, tab1[-n / 2]);
} else {
ep_add(r, r, tab1[-n / 2]);
}
}
n = *t3;
if (n > 0) {
ep_copy(u, tab1[n / 2]);
fp_mul(u->x, u->x, ep_curve_get_beta());
if (sl1 == BN_NEG) {
ep_neg(u, u);
}
ep_add(r, r, u);
}
if (n < 0) {
ep_copy(u, tab1[-n / 2]);
fp_mul(u->x, u->x, ep_curve_get_beta());
if (sl1 == BN_NEG) {
ep_neg(u, u);
}
ep_sub(r, r, u);
}
}
/* Convert r to affine coordinates. */
ep_norm(r, r);
}
CATCH_ANY {
THROW(ERR_CAUGHT);
}
FINALLY {
bn_free(ord);
bn_free(k0);
bn_free(k1);
bn_free(l0);
bn_free(l1);
ep_free(u);
if (!g) {
for (i = 0; i < 1 << (EP_WIDTH - 2); i++) {
ep_free(tab0[i]);
}
}
/* Free the precomputation tables. */
for (i = 0; i < 1 << (EP_WIDTH - 2); i++) {
ep_free(tab1[i]);
}
for (i = 0; i < 3; i++) {
bn_free(v1[i]);
bn_free(v2[i]);
}
}
}
void ep_mul_sim_joint(ep_t r, const ep_t p, const bn_t k, const ep_t q,
const bn_t m) {
ep_t t[5];
int u_i, len, offset;
int8_t jsf[2 * (FP_BITS + 1)];
int i;
ep_null(t[0]);
ep_null(t[1]);
ep_null(t[2]);
ep_null(t[3]);
ep_null(t[4]);
TRY {
for (i = 0; i < 5; i++) {
ep_new(t[i]);
}
ep_set_infty(t[0]);
ep_copy(t[1], q);
ep_copy(t[2], p);
ep_add(t[3], p, q);
ep_sub(t[4], p, q);
#if defined(EP_MIXED)
ep_norm_sim(t + 3, (const ep_t *)t + 3, 2);
#endif
len = 2 * (FP_BITS + 1);
bn_rec_jsf(jsf, &len, k, m);
ep_set_infty(r);
offset = MAX(bn_bits(k), bn_bits(m)) + 1;
for (i = len - 1; i >= 0; i--) {
ep_dbl(r, r);
if (jsf[i] != 0 && jsf[i] == -jsf[i + offset]) {
u_i = jsf[i] * 2 + jsf[i + offset];
if (u_i < 0) {
ep_sub(r, r, t[4]);
} else {
ep_add(r, r, t[4]);
}
} else {
u_i = jsf[i] * 2 + jsf[i + offset];
if (u_i < 0) {
ep_sub(r, r, t[-u_i]);
} else {
ep_add(r, r, t[u_i]);
}
}
}
ep_norm(r, r);
}
CATCH_ANY {
THROW(ERR_CAUGHT);
}
FINALLY {
for (i = 0; i < 5; i++) {
ep_free(t[i]);
}
}
}
void ep_mul_sim_trick(ep_t r, const ep_t p, const bn_t k, const ep_t q,
const bn_t m) {
ep_t t0[1 << (EP_WIDTH / 2)], t1[1 << (EP_WIDTH / 2)], t[1 << EP_WIDTH];
bn_t n;
int l0, l1, w = EP_WIDTH / 2;
uint8_t w0[CEIL(FP_BITS + 1, w)], w1[CEIL(FP_BITS + 1, w)];
bn_null(n);
for (int i = 0; i < 1 << EP_WIDTH; i++) {
ep_null(t[i]);
}
for (int i = 0; i < 1 << (EP_WIDTH / 2); i++) {
ep_null(t0[i]);
ep_null(t1[i]);
}
TRY {
bn_new(n);
ep_curve_get_ord(n);
for (int i = 0; i < (1 << w); i++) {
ep_new(t0[i]);
ep_new(t1[i]);
}
for (int i = 0; i < (1 << EP_WIDTH); i++) {
ep_new(t[i]);
}
ep_set_infty(t0[0]);
for (int i = 1; i < (1 << w); i++) {
ep_add(t0[i], t0[i - 1], p);
}
ep_set_infty(t1[0]);
for (int i = 1; i < (1 << w); i++) {
ep_add(t1[i], t1[i - 1], q);
}
for (int i = 0; i < (1 << w); i++) {
for (int j = 0; j < (1 << w); j++) {
ep_add(t[(i << w) + j], t0[i], t1[j]);
}
}
#if defined(EP_MIXED)
ep_norm_sim(t + 1, (const ep_t *)t + 1, (1 << (EP_WIDTH)) - 1);
#endif
l0 = l1 = CEIL(FP_BITS, w);
bn_rec_win(w0, &l0, k, w);
bn_rec_win(w1, &l1, m, w);
for (int i = l0; i < l1; i++) {
w0[i] = 0;
}
for (int i = l1; i < l0; i++) {
w1[i] = 0;
}
ep_set_infty(r);
for (int i = MAX(l0, l1) - 1; i >= 0; i--) {
for (int j = 0; j < w; j++) {
ep_dbl(r, r);
}
ep_add(r, r, t[(w0[i] << w) + w1[i]]);
}
ep_norm(r, r);
} CATCH_ANY {
THROW(ERR_CAUGHT);
}
FINALLY {
bn_free(n);
for (int i = 0; i < (1 << w); i++) {
ep_free(t0[i]);
ep_free(t1[i]);
}
for (int i = 0; i < (1 << EP_WIDTH); i++) {
ep_free(t[i]);
}
}
}
/**
* Multiplies and adds two prime elliptic curve points simultaneously,
* optionally choosing the first point as the generator depending on an optional
* table of precomputed points.
*
* @param[out] r - the result.
* @param[in] p - the first point to multiply.
* @param[in] k - the first integer.
* @param[in] q - the second point to multiply.
* @param[in] m - the second integer.
* @param[in] t - the pointer to the precomputed table.
*/
static void ep_mul_sim_plain(ep_t r, const ep_t p, const bn_t k, const ep_t q,
const bn_t m, const ep_t *t) {
int len, l0, l1, i, n0, n1, w, gen;
int8_t naf0[FP_BITS + 1], naf1[FP_BITS + 1], *_k, *_m;
ep_t t0[1 << (EP_WIDTH - 2)];
ep_t t1[1 << (EP_WIDTH - 2)];
for (i = 0; i < (1 << (EP_WIDTH - 2)); i++) {
ep_null(t0[i]);
ep_null(t1[i]);
}
TRY {
gen = (t == NULL ? 0 : 1);
if (!gen) {
for (i = 0; i < (1 << (EP_WIDTH - 2)); i++) {
ep_new(t0[i]);
}
ep_tab(t0, p, EP_WIDTH);
t = (const ep_t *)t0;
}
/* Prepare the precomputation table. */
for (i = 0; i < (1 << (EP_WIDTH - 2)); i++) {
ep_new(t1[i]);
}
/* Compute the precomputation table. */
ep_tab(t1, q, EP_WIDTH);
/* Compute the w-TNAF representation of k. */
if (gen) {
w = EP_DEPTH;
} else {
w = EP_WIDTH;
}
l0 = l1 = FP_BITS + 1;
bn_rec_naf(naf0, &l0, k, w);
bn_rec_naf(naf1, &l1, m, EP_WIDTH);
len = MAX(l0, l1);
_k = naf0 + len - 1;
_m = naf1 + len - 1;
for (i = l0; i < len; i++)
naf0[i] = 0;
for (i = l1; i < len; i++)
naf1[i] = 0;
ep_set_infty(r);
for (i = len - 1; i >= 0; i--, _k--, _m--) {
ep_dbl(r, r);
n0 = *_k;
n1 = *_m;
if (n0 > 0) {
ep_add(r, r, t[n0 / 2]);
}
if (n0 < 0) {
ep_sub(r, r, t[-n0 / 2]);
}
if (n1 > 0) {
ep_add(r, r, t1[n1 / 2]);
}
if (n1 < 0) {
ep_sub(r, r, t1[-n1 / 2]);
}
}
/* Convert r to affine coordinates. */
ep_norm(r, r);
}
CATCH_ANY {
THROW(ERR_CAUGHT);
}
FINALLY {
/* Free the precomputation tables. */
if (!gen) {
for (i = 0; i < 1 << (EP_WIDTH - 2); i++) {
ep_free(t0[i]);
}
}
for (i = 0; i < 1 << (EP_WIDTH - 2); i++) {
ep_free(t1[i]);
}
}
}
