EXT_RETURN tls_construct_stoc_next_proto_neg(SSL *s, WPACKET *pkt,
unsigned int context, X509 *x,
size_t chainidx, int *al)
{
const unsigned char *npa;
unsigned int npalen;
int ret;
int npn_seen = s->s3->npn_seen;
s->s3->npn_seen = 0;
if (!npn_seen || s->ctx->ext.npn_advertised_cb == NULL)
return EXT_RETURN_NOT_SENT;
ret = s->ctx->ext.npn_advertised_cb(s, &npa, &npalen,
s->ctx->ext.npn_advertised_cb_arg);
if (ret == SSL_TLSEXT_ERR_OK) {
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_next_proto_neg)
|| !WPACKET_sub_memcpy_u16(pkt, npa, npalen)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_NEXT_PROTO_NEG,
ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
s->s3->npn_seen = 1;
}
return EXT_RETURN_SENT;
}
int tls_construct_ctos_alpn(SSL *s, WPACKET *pkt, int *al)
{
s->s3->alpn_sent = 0;
/*
* finish_md_len is non-zero during a renegotiation, so
* this avoids sending ALPN during the renegotiation
*/
if (s->alpn_client_proto_list == NULL || s->s3->tmp.finish_md_len != 0)
return 1;
if (!WPACKET_put_bytes_u16(pkt,
TLSEXT_TYPE_application_layer_protocol_negotiation)
/* Sub-packet ALPN extension */
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_sub_memcpy_u16(pkt, s->alpn_client_proto_list,
s->alpn_client_proto_list_len)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_ALPN, ERR_R_INTERNAL_ERROR);
return 0;
}
s->s3->alpn_sent = 1;
return 1;
}
int tls_construct_stoc_next_proto_neg(SSL *s, WPACKET *pkt, int *al)
{
const unsigned char *npa;
unsigned int npalen;
int ret;
int next_proto_neg_seen = s->s3->next_proto_neg_seen;
s->s3->next_proto_neg_seen = 0;
if (!next_proto_neg_seen || s->ctx->next_protos_advertised_cb == NULL)
return 1;
ret = s->ctx->next_protos_advertised_cb(s, &npa, &npalen,
s->ctx->next_protos_advertised_cb_arg);
if (ret == SSL_TLSEXT_ERR_OK) {
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_next_proto_neg)
|| !WPACKET_sub_memcpy_u16(pkt, npa, npalen)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_NEXT_PROTO_NEG,
ERR_R_INTERNAL_ERROR);
return 0;
}
s->s3->next_proto_neg_seen = 1;
}
return 1;
}
int tls_construct_stoc_key_share(SSL *s, WPACKET *pkt, int *al)
{
unsigned char *encodedPoint;
size_t encoded_pt_len = 0;
EVP_PKEY *ckey = s->s3->peer_tmp, *skey = NULL;
if (s->hit)
return 1;
if (ckey == NULL) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_key_share)
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_put_bytes_u16(pkt, s->s3->group_id)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
skey = ssl_generate_pkey(ckey);
if (skey == NULL) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_MALLOC_FAILURE);
return 0;
}
/* Generate encoding of server key */
encoded_pt_len = EVP_PKEY_get1_tls_encodedpoint(skey, &encodedPoint);
if (encoded_pt_len == 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_EC_LIB);
EVP_PKEY_free(skey);
return 0;
}
if (!WPACKET_sub_memcpy_u16(pkt, encodedPoint, encoded_pt_len)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
EVP_PKEY_free(skey);
OPENSSL_free(encodedPoint);
return 0;
}
OPENSSL_free(encodedPoint);
/* This causes the crypto state to be updated based on the derived keys */
s->s3->tmp.pkey = skey;
if (ssl_derive(s, skey, ckey, 1) == 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
return 1;
}
static int add_key_share(SSL *s, WPACKET *pkt, unsigned int curve_id)
{
unsigned char *encoded_point;
EVP_PKEY *key_share_key;
size_t encodedlen;
key_share_key = ssl_generate_pkey_curve(curve_id);
if (key_share_key == NULL) {
SSLerr(SSL_F_ADD_KEY_SHARE, ERR_R_EVP_LIB);
return 0;
}
/* Encode the public key. */
encodedlen = EVP_PKEY_get1_tls_encodedpoint(key_share_key,
&encoded_point);
if (encodedlen == 0) {
SSLerr(SSL_F_ADD_KEY_SHARE, ERR_R_EC_LIB);
EVP_PKEY_free(key_share_key);
return 0;
}
/* Create KeyShareEntry */
if (!WPACKET_put_bytes_u16(pkt, curve_id)
|| !WPACKET_sub_memcpy_u16(pkt, encoded_point, encodedlen)) {
SSLerr(SSL_F_ADD_KEY_SHARE, ERR_R_INTERNAL_ERROR);
EVP_PKEY_free(key_share_key);
OPENSSL_free(encoded_point);
return 0;
}
/*
* TODO(TLS1.3): When changing to send more than one key_share we're
* going to need to be able to save more than one EVP_PKEY. For now
* we reuse the existing tmp.pkey
*/
s->s3->tmp.pkey = key_share_key;
s->s3->group_id = curve_id;
OPENSSL_free(encoded_point);
return 1;
}
int tls_construct_ctos_session_ticket(SSL *s, WPACKET *pkt,
unsigned int context, X509 *x,
size_t chainidx, int *al)
{
size_t ticklen;
if (!tls_use_ticket(s))
return 1;
if (!s->new_session && s->session != NULL
&& s->session->ext.tick != NULL
&& s->session->ssl_version != TLS1_3_VERSION) {
ticklen = s->session->ext.ticklen;
} else if (s->session && s->ext.session_ticket != NULL
&& s->ext.session_ticket->data != NULL) {
ticklen = s->ext.session_ticket->length;
s->session->ext.tick = OPENSSL_malloc(ticklen);
if (s->session->ext.tick == NULL) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_SESSION_TICKET,
ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(s->session->ext.tick,
s->ext.session_ticket->data, ticklen);
s->session->ext.ticklen = ticklen;
} else {
ticklen = 0;
}
if (ticklen == 0 && s->ext.session_ticket != NULL &&
s->ext.session_ticket->data == NULL)
return 1;
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_session_ticket)
|| !WPACKET_sub_memcpy_u16(pkt, s->session->ext.tick, ticklen)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_SESSION_TICKET, ERR_R_INTERNAL_ERROR);
return 0;
}
return 1;
}
int tls_construct_ctos_alpn(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
size_t chainidx, int *al)
{
s->s3->alpn_sent = 0;
if (s->ext.alpn == NULL || !SSL_IS_FIRST_HANDSHAKE(s))
return 1;
if (!WPACKET_put_bytes_u16(pkt,
TLSEXT_TYPE_application_layer_protocol_negotiation)
/* Sub-packet ALPN extension */
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_sub_memcpy_u16(pkt, s->ext.alpn, s->ext.alpn_len)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_ALPN, ERR_R_INTERNAL_ERROR);
return 0;
}
s->s3->alpn_sent = 1;
return 1;
}
int tls_construct_ctos_server_name(SSL *s, WPACKET *pkt, int *al)
{
if (s->tlsext_hostname == NULL)
return 1;
/* Add TLS extension servername to the Client Hello message */
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_server_name)
/* Sub-packet for server_name extension */
|| !WPACKET_start_sub_packet_u16(pkt)
/* Sub-packet for servername list (always 1 hostname)*/
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_put_bytes_u8(pkt, TLSEXT_NAMETYPE_host_name)
|| !WPACKET_sub_memcpy_u16(pkt, s->tlsext_hostname,
strlen(s->tlsext_hostname))
|| !WPACKET_close(pkt)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_SERVER_NAME, ERR_R_INTERNAL_ERROR);
return 0;
}
return 1;
}
EXT_RETURN tls_construct_stoc_key_share(SSL *s, WPACKET *pkt,
unsigned int context, X509 *x,
size_t chainidx, int *al)
{
#ifndef OPENSSL_NO_TLS1_3
unsigned char *encodedPoint;
size_t encoded_pt_len = 0;
EVP_PKEY *ckey = s->s3->peer_tmp, *skey = NULL;
if (ckey == NULL) {
/* No key_share received from client */
if (s->hello_retry_request) {
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_key_share)
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_put_bytes_u16(pkt, s->s3->group_id)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE,
ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
return EXT_RETURN_SENT;
}
/* Must be resuming. */
if (!s->hit || !tls13_generate_handshake_secret(s, NULL, 0)) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
return EXT_RETURN_NOT_SENT;
}
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_key_share)
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_put_bytes_u16(pkt, s->s3->group_id)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
skey = ssl_generate_pkey(ckey);
if (skey == NULL) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_MALLOC_FAILURE);
return EXT_RETURN_FAIL;
}
/* Generate encoding of server key */
encoded_pt_len = EVP_PKEY_get1_tls_encodedpoint(skey, &encodedPoint);
if (encoded_pt_len == 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_EC_LIB);
EVP_PKEY_free(skey);
return EXT_RETURN_FAIL;
}
if (!WPACKET_sub_memcpy_u16(pkt, encodedPoint, encoded_pt_len)
|| !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
EVP_PKEY_free(skey);
OPENSSL_free(encodedPoint);
return EXT_RETURN_FAIL;
}
OPENSSL_free(encodedPoint);
/* This causes the crypto state to be updated based on the derived keys */
s->s3->tmp.pkey = skey;
if (ssl_derive(s, skey, ckey, 1) == 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
#endif
return EXT_RETURN_SENT;
}
/*
* Construct the pre_shared_key extension
*/
int tls_construct_ctos_psk(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
size_t chainidx, int *al)
{
#ifndef OPENSSL_NO_TLS1_3
uint32_t now, agesec, agems;
size_t hashsize, binderoffset, msglen;
unsigned char *binder = NULL, *msgstart = NULL;
const EVP_MD *md;
int ret = 0;
s->session->ext.tick_identity = TLSEXT_PSK_BAD_IDENTITY;
/*
* If this is an incompatible or new session then we have nothing to resume
* so don't add this extension.
*/
if (s->session->ssl_version != TLS1_3_VERSION
|| s->session->ext.ticklen == 0)
return 1;
if (s->session->cipher == NULL) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_PSK, ERR_R_INTERNAL_ERROR);
goto err;
}
md = ssl_md(s->session->cipher->algorithm2);
if (md == NULL) {
/* Don't recognise this cipher so we can't use the session. Ignore it */
return 1;
}
/*
* Technically the C standard just says time() returns a time_t and says
* nothing about the encoding of that type. In practice most implementations
* follow POSIX which holds it as an integral type in seconds since epoch.
* We've already made the assumption that we can do this in multiple places
* in the code, so portability shouldn't be an issue.
*/
now = (uint32_t)time(NULL);
agesec = now - (uint32_t)s->session->time;
if (s->session->ext.tick_lifetime_hint < agesec) {
/* Ticket is too old. Ignore it. */
return 1;
}
/*
* Calculate age in ms. We're just doing it to nearest second. Should be
* good enough.
*/
agems = agesec * (uint32_t)1000;
if (agesec != 0 && agems / (uint32_t)1000 != agesec) {
/*
* Overflow. Shouldn't happen unless this is a *really* old session. If
* so we just ignore it.
*/
return 1;
}
/*
* Obfuscate the age. Overflow here is fine, this addition is supposed to
* be mod 2^32.
*/
agems += s->session->ext.tick_age_add;
hashsize = EVP_MD_size(md);
/* Create the extension, but skip over the binder for now */
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_psk)
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_sub_memcpy_u16(pkt, s->session->ext.tick,
s->session->ext.ticklen)
|| !WPACKET_put_bytes_u32(pkt, agems)
|| !WPACKET_close(pkt)
|| !WPACKET_get_total_written(pkt, &binderoffset)
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_sub_allocate_bytes_u8(pkt, hashsize, &binder)
|| !WPACKET_close(pkt)
|| !WPACKET_close(pkt)
|| !WPACKET_get_total_written(pkt, &msglen)
/*
* We need to fill in all the sub-packet lengths now so we can
* calculate the HMAC of the message up to the binders
*/
|| !WPACKET_fill_lengths(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_PSK, ERR_R_INTERNAL_ERROR);
goto err;
}
msgstart = WPACKET_get_curr(pkt) - msglen;
if (tls_psk_do_binder(s, md, msgstart, binderoffset, NULL, binder,
s->session, 1) != 1) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_PSK, ERR_R_INTERNAL_ERROR);
goto err;
}
s->session->ext.tick_identity = 0;
ret = 1;
err:
return ret;
#else
return 1;
#endif
}
int tls_construct_ctos_key_share(SSL *s, WPACKET *pkt, int *al)
{
size_t i, sharessent = 0, num_curves = 0;
const unsigned char *pcurves = NULL;
/* key_share extension */
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_key_share)
/* Extension data sub-packet */
|| !WPACKET_start_sub_packet_u16(pkt)
/* KeyShare list sub-packet */
|| !WPACKET_start_sub_packet_u16(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
pcurves = s->tlsext_supportedgroupslist;
if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
/*
* TODO(TLS1.3): Make the number of key_shares sent configurable. For
* now, just send one
*/
for (i = 0; i < num_curves && sharessent < 1; i++, pcurves += 2) {
unsigned char *encodedPoint = NULL;
unsigned int curve_id = 0;
EVP_PKEY *key_share_key = NULL;
size_t encodedlen;
if (!tls_curve_allowed(s, pcurves, SSL_SECOP_CURVE_SUPPORTED))
continue;
if (s->s3->tmp.pkey != NULL) {
/* Shouldn't happen! */
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
/* Generate a key for this key_share */
curve_id = (pcurves[0] << 8) | pcurves[1];
key_share_key = ssl_generate_pkey_curve(curve_id);
if (key_share_key == NULL) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_EVP_LIB);
return 0;
}
/* Encode the public key. */
encodedlen = EVP_PKEY_get1_tls_encodedpoint(key_share_key,
&encodedPoint);
if (encodedlen == 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_EC_LIB);
EVP_PKEY_free(key_share_key);
return 0;
}
/* Create KeyShareEntry */
if (!WPACKET_put_bytes_u16(pkt, curve_id)
|| !WPACKET_sub_memcpy_u16(pkt, encodedPoint, encodedlen)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_INTERNAL_ERROR);
EVP_PKEY_free(key_share_key);
OPENSSL_free(encodedPoint);
return 0;
}
/*
* TODO(TLS1.3): When changing to send more than one key_share we're
* going to need to be able to save more than one EVP_PKEY. For now
* we reuse the existing tmp.pkey
*/
s->s3->group_id = curve_id;
s->s3->tmp.pkey = key_share_key;
sharessent++;
OPENSSL_free(encodedPoint);
}
if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
return 1;
}
