EXT_RETURN tls_construct_stoc_supported_groups(SSL *s, WPACKET *pkt,
unsigned int context, X509 *x,
size_t chainidx, int *al)
{
const unsigned char *groups;
size_t numgroups, i, first = 1;
/* s->s3->group_id is non zero if we accepted a key_share */
if (s->s3->group_id == 0)
return EXT_RETURN_NOT_SENT;
/* Get our list of supported groups */
if (!tls1_get_curvelist(s, 0, &groups, &numgroups) || numgroups == 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_SUPPORTED_GROUPS, ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
/* Copy group ID if supported */
for (i = 0; i < numgroups; i++, groups += 2) {
if (tls_curve_allowed(s, groups, SSL_SECOP_CURVE_SUPPORTED)) {
if (first) {
/*
* Check if the client is already using our preferred group. If
* so we don't need to add this extension
*/
if (s->s3->group_id == GET_GROUP_ID(groups, 0))
return EXT_RETURN_NOT_SENT;
/* Add extension header */
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_supported_groups)
/* Sub-packet for supported_groups extension */
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_start_sub_packet_u16(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_SUPPORTED_GROUPS,
ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
first = 0;
}
if (!WPACKET_put_bytes_u16(pkt, GET_GROUP_ID(groups, 0))) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_SUPPORTED_GROUPS,
ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
}
}
if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_STOC_SUPPORTED_GROUPS, ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
return EXT_RETURN_SENT;
}
int tls_construct_ctos_supported_groups(SSL *s, WPACKET *pkt,
unsigned int context, X509 *x,
size_t chainidx, int *al)
{
const unsigned char *pcurves = NULL, *pcurvestmp;
size_t num_curves = 0, i;
if (!use_ecc(s))
return 1;
/*
* Add TLS extension supported_groups to the ClientHello message
*/
/* TODO(TLS1.3): Add support for DHE groups */
pcurves = s->ext.supportedgroups;
if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_GROUPS,
ERR_R_INTERNAL_ERROR);
return 0;
}
pcurvestmp = pcurves;
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_supported_groups)
/* Sub-packet for supported_groups extension */
|| !WPACKET_start_sub_packet_u16(pkt)
|| !WPACKET_start_sub_packet_u16(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_GROUPS,
ERR_R_INTERNAL_ERROR);
return 0;
}
/* Copy curve ID if supported */
for (i = 0; i < num_curves; i++, pcurvestmp += 2) {
if (tls_curve_allowed(s, pcurvestmp, SSL_SECOP_CURVE_SUPPORTED)) {
if (!WPACKET_put_bytes_u8(pkt, pcurvestmp[0])
|| !WPACKET_put_bytes_u8(pkt, pcurvestmp[1])) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_GROUPS,
ERR_R_INTERNAL_ERROR);
return 0;
}
}
}
if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_SUPPORTED_GROUPS,
ERR_R_INTERNAL_ERROR);
return 0;
}
return 1;
}
/*
* Checks a list of |groups| to determine if the |group_id| is in it. If it is
* and |checkallow| is 1 then additionally check if the group is allowed to be
* used. Returns 1 if the group is in the list (and allowed if |checkallow| is
* 1) or 0 otherwise.
*/
static int check_in_list(SSL *s, unsigned int group_id,
const unsigned char *groups, size_t num_groups,
int checkallow)
{
size_t i;
if (groups == NULL || num_groups == 0)
return 0;
for (i = 0; i < num_groups; i++, groups += 2) {
unsigned int share_id = (groups[0] << 8) | (groups[1]);
if (group_id == share_id
&& (!checkallow
|| tls_curve_allowed(s, groups, SSL_SECOP_CURVE_CHECK))) {
break;
}
}
/* If i == num_groups then not in the list */
return i < num_groups;
}
int tls_construct_ctos_key_share(SSL *s, WPACKET *pkt, unsigned int context,
X509 *x, size_t chainidx, int *al)
{
#ifndef OPENSSL_NO_TLS1_3
size_t i, num_curves = 0;
const unsigned char *pcurves = NULL;
unsigned int curve_id = 0;
/* 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->ext.supportedgroups;
if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
if (s->s3->tmp.pkey != NULL) {
/* Shouldn't happen! */
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
*/
if (s->s3->group_id != 0) {
curve_id = s->s3->group_id;
} else {
for (i = 0; i < num_curves; i++, pcurves += 2) {
if (!tls_curve_allowed(s, pcurves, SSL_SECOP_CURVE_SUPPORTED))
continue;
curve_id = bytestogroup(pcurves);
break;
}
}
if (curve_id == 0) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
return 0;
}
if (!add_key_share(s, pkt, curve_id))
return 0;
if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) {
SSLerr(SSL_F_TLS_CONSTRUCT_CTOS_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
#endif
return 1;
}
int tls_parse_stoc_key_share(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
size_t chainidx, int *al)
{
#ifndef OPENSSL_NO_TLS1_3
unsigned int group_id;
PACKET encoded_pt;
EVP_PKEY *ckey = s->s3->tmp.pkey, *skey = NULL;
/* Sanity check */
if (ckey == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
if (!PACKET_get_net_2(pkt, &group_id)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_LENGTH_MISMATCH);
return 0;
}
if ((context & EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0) {
unsigned const char *pcurves = NULL;
size_t i, num_curves;
if (PACKET_remaining(pkt) != 0) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_LENGTH_MISMATCH);
return 0;
}
/*
* It is an error if the HelloRetryRequest wants a key_share that we
* already sent in the first ClientHello
*/
if (group_id == s->s3->group_id) {
*al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_BAD_KEY_SHARE);
return 0;
}
/* Validate the selected group is one we support */
pcurves = s->ext.supportedgroups;
if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
for (i = 0; i < num_curves; i++, pcurves += 2) {
if (group_id == bytestogroup(pcurves))
break;
}
if (i >= num_curves
|| !tls_curve_allowed(s, pcurves, SSL_SECOP_CURVE_SUPPORTED)) {
*al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_BAD_KEY_SHARE);
return 0;
}
s->s3->group_id = group_id;
EVP_PKEY_free(s->s3->tmp.pkey);
s->s3->tmp.pkey = NULL;
return 1;
}
if (group_id != s->s3->group_id) {
/*
* This isn't for the group that we sent in the original
* key_share!
*/
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_BAD_KEY_SHARE);
return 0;
}
if (!PACKET_as_length_prefixed_2(pkt, &encoded_pt)
|| PACKET_remaining(&encoded_pt) == 0) {
*al = SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_LENGTH_MISMATCH);
return 0;
}
skey = ssl_generate_pkey(ckey);
if (skey == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, ERR_R_MALLOC_FAILURE);
return 0;
}
if (!EVP_PKEY_set1_tls_encodedpoint(skey, PACKET_data(&encoded_pt),
PACKET_remaining(&encoded_pt))) {
*al = SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_BAD_ECPOINT);
EVP_PKEY_free(skey);
return 0;
}
if (ssl_derive(s, ckey, skey, 1) == 0) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, ERR_R_INTERNAL_ERROR);
EVP_PKEY_free(skey);
return 0;
}
EVP_PKEY_free(skey);
#endif
return 1;
}
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;
}
