Split extensions code into core extensions and server extensions code
Later we will have client extensions code too.
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
diff --git a/ssl/statem/extensions_srvr.c b/ssl/statem/extensions_srvr.c
new file mode 100644
index 0000000..38a6bef
--- /dev/null
+++ b/ssl/statem/extensions_srvr.c
@@ -0,0 +1,649 @@
+/*
+ * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <openssl/ocsp.h>
+#include "../ssl_locl.h"
+#include "statem_locl.h"
+
+/*
+ * Parse the client's renegotiation binding and abort if it's not right
+ */
+int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al)
+{
+ unsigned int ilen;
+ const unsigned char *data;
+
+ /* Parse the length byte */
+ if (!PACKET_get_1(pkt, &ilen)
+ || !PACKET_get_bytes(pkt, &data, ilen)) {
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
+ SSL_R_RENEGOTIATION_ENCODING_ERR);
+ *al = SSL_AD_ILLEGAL_PARAMETER;
+ return 0;
+ }
+
+ /* Check that the extension matches */
+ if (ilen != s->s3->previous_client_finished_len) {
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
+ SSL_R_RENEGOTIATION_MISMATCH);
+ *al = SSL_AD_HANDSHAKE_FAILURE;
+ return 0;
+ }
+
+ if (memcmp(data, s->s3->previous_client_finished,
+ s->s3->previous_client_finished_len)) {
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
+ SSL_R_RENEGOTIATION_MISMATCH);
+ *al = SSL_AD_HANDSHAKE_FAILURE;
+ return 0;
+ }
+
+ s->s3->send_connection_binding = 1;
+
+ return 1;
+}
+
+int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al)
+{
+ unsigned int servname_type;
+ PACKET sni, hostname;
+
+ /*-
+ * The servername extension is treated as follows:
+ *
+ * - Only the hostname type is supported with a maximum length of 255.
+ * - The servername is rejected if too long or if it contains zeros,
+ * in which case an fatal alert is generated.
+ * - The servername field is maintained together with the session cache.
+ * - When a session is resumed, the servername call back invoked in order
+ * to allow the application to position itself to the right context.
+ * - The servername is acknowledged if it is new for a session or when
+ * it is identical to a previously used for the same session.
+ * Applications can control the behaviour. They can at any time
+ * set a 'desirable' servername for a new SSL object. This can be the
+ * case for example with HTTPS when a Host: header field is received and
+ * a renegotiation is requested. In this case, a possible servername
+ * presented in the new client hello is only acknowledged if it matches
+ * the value of the Host: field.
+ * - Applications must use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
+ * if they provide for changing an explicit servername context for the
+ * session, i.e. when the session has been established with a servername
+ * extension.
+ * - On session reconnect, the servername extension may be absent.
+ *
+ */
+ if (!PACKET_as_length_prefixed_2(pkt, &sni)
+ /* ServerNameList must be at least 1 byte long. */
+ || PACKET_remaining(&sni) == 0) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ /*
+ * Although the server_name extension was intended to be
+ * extensible to new name types, RFC 4366 defined the
+ * syntax inextensibility and OpenSSL 1.0.x parses it as
+ * such.
+ * RFC 6066 corrected the mistake but adding new name types
+ * is nevertheless no longer feasible, so act as if no other
+ * SNI types can exist, to simplify parsing.
+ *
+ * Also note that the RFC permits only one SNI value per type,
+ * i.e., we can only have a single hostname.
+ */
+ if (!PACKET_get_1(&sni, &servname_type)
+ || servname_type != TLSEXT_NAMETYPE_host_name
+ || !PACKET_as_length_prefixed_2(&sni, &hostname)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ if (!s->hit) {
+ if (PACKET_remaining(&hostname) > TLSEXT_MAXLEN_host_name) {
+ *al = TLS1_AD_UNRECOGNIZED_NAME;
+ return 0;
+ }
+
+ if (PACKET_contains_zero_byte(&hostname)) {
+ *al = TLS1_AD_UNRECOGNIZED_NAME;
+ return 0;
+ }
+
+ if (!PACKET_strndup(&hostname, &s->session->tlsext_hostname)) {
+ *al = TLS1_AD_INTERNAL_ERROR;
+ return 0;
+ }
+
+ s->servername_done = 1;
+ } else {
+ /*
+ * TODO(openssl-team): if the SNI doesn't match, we MUST
+ * fall back to a full handshake.
+ */
+ s->servername_done = s->session->tlsext_hostname
+ && PACKET_equal(&hostname, s->session->tlsext_hostname,
+ strlen(s->session->tlsext_hostname));
+ }
+
+ return 1;
+}
+
+#ifndef OPENSSL_NO_SRP
+int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al)
+{
+ PACKET srp_I;
+
+ if (!PACKET_as_length_prefixed_1(pkt, &srp_I)
+ || PACKET_contains_zero_byte(&srp_I)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ /*
+ * TODO(openssl-team): currently, we re-authenticate the user
+ * upon resumption. Instead, we MUST ignore the login.
+ */
+ if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) {
+ *al = TLS1_AD_INTERNAL_ERROR;
+ return 0;
+ }
+
+ return 1;
+}
+#endif
+
+#ifndef OPENSSL_NO_EC
+int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al)
+{
+ PACKET ec_point_format_list;
+
+ if (!PACKET_as_length_prefixed_1(pkt, &ec_point_format_list)
+ || PACKET_remaining(&ec_point_format_list) == 0) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ if (!s->hit) {
+ if (!PACKET_memdup(&ec_point_format_list,
+ &s->session->tlsext_ecpointformatlist,
+ &s->session->tlsext_ecpointformatlist_length)) {
+ *al = TLS1_AD_INTERNAL_ERROR;
+ return 0;
+ }
+ }
+
+ return 1;
+}
+#endif /* OPENSSL_NO_EC */
+
+int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al)
+{
+ if (s->tls_session_ticket_ext_cb &&
+ !s->tls_session_ticket_ext_cb(s, PACKET_data(pkt),
+ PACKET_remaining(pkt),
+ s->tls_session_ticket_ext_cb_arg)) {
+ *al = TLS1_AD_INTERNAL_ERROR;
+ return 0;
+ }
+
+ return 1;
+}
+
+int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al)
+{
+ PACKET supported_sig_algs;
+
+ if (!PACKET_as_length_prefixed_2(pkt, &supported_sig_algs)
+ || (PACKET_remaining(&supported_sig_algs) % 2) != 0
+ || PACKET_remaining(&supported_sig_algs) == 0) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ if (!s->hit && !tls1_save_sigalgs(s, PACKET_data(&supported_sig_algs),
+ PACKET_remaining(&supported_sig_algs))) {
+ *al = TLS1_AD_INTERNAL_ERROR;
+ return 0;
+ }
+
+ return 1;
+}
+
+int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al)
+{
+ if (!PACKET_get_1(pkt, (unsigned int *)&s->tlsext_status_type)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+#ifndef OPENSSL_NO_OCSP
+ if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
+ const unsigned char *ext_data;
+ PACKET responder_id_list, exts;
+ if (!PACKET_get_length_prefixed_2 (pkt, &responder_id_list)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ /*
+ * We remove any OCSP_RESPIDs from a previous handshake
+ * to prevent unbounded memory growth - CVE-2016-6304
+ */
+ sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids, OCSP_RESPID_free);
+ if (PACKET_remaining(&responder_id_list) > 0) {
+ s->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null();
+ if (s->tlsext_ocsp_ids == NULL) {
+ *al = SSL_AD_INTERNAL_ERROR;
+ return 0;
+ }
+ } else {
+ s->tlsext_ocsp_ids = NULL;
+ }
+
+ while (PACKET_remaining(&responder_id_list) > 0) {
+ OCSP_RESPID *id;
+ PACKET responder_id;
+ const unsigned char *id_data;
+
+ if (!PACKET_get_length_prefixed_2(&responder_id_list,
+ &responder_id)
+ || PACKET_remaining(&responder_id) == 0) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ id_data = PACKET_data(&responder_id);
+ /* TODO(size_t): Convert d2i_* to size_t */
+ id = d2i_OCSP_RESPID(NULL, &id_data,
+ (int)PACKET_remaining(&responder_id));
+ if (id == NULL) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ if (id_data != PACKET_end(&responder_id)) {
+ OCSP_RESPID_free(id);
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id)) {
+ OCSP_RESPID_free(id);
+ *al = SSL_AD_INTERNAL_ERROR;
+ return 0;
+ }
+ }
+
+ /* Read in request_extensions */
+ if (!PACKET_as_length_prefixed_2(pkt, &exts)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ if (PACKET_remaining(&exts) > 0) {
+ ext_data = PACKET_data(&exts);
+ sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
+ X509_EXTENSION_free);
+ s->tlsext_ocsp_exts =
+ d2i_X509_EXTENSIONS(NULL, &ext_data,
+ (int)PACKET_remaining(&exts));
+ if (s->tlsext_ocsp_exts == NULL || ext_data != PACKET_end(&exts)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+ }
+ } else
+#endif
+ {
+ /*
+ * We don't know what to do with any other type so ignore it.
+ */
+ s->tlsext_status_type = -1;
+ }
+
+ return 1;
+}
+
+#ifndef OPENSSL_NO_NEXTPROTONEG
+int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al)
+{
+ if (s->s3->tmp.finish_md_len == 0) {
+ /*-
+ * We shouldn't accept this extension on a
+ * renegotiation.
+ *
+ * s->new_session will be set on renegotiation, but we
+ * probably shouldn't rely that it couldn't be set on
+ * the initial renegotiation too in certain cases (when
+ * there's some other reason to disallow resuming an
+ * earlier session -- the current code won't be doing
+ * anything like that, but this might change).
+ *
+ * A valid sign that there's been a previous handshake
+ * in this connection is if s->s3->tmp.finish_md_len >
+ * 0. (We are talking about a check that will happen
+ * in the Hello protocol round, well before a new
+ * Finished message could have been computed.)
+ */
+ s->s3->next_proto_neg_seen = 1;
+ }
+
+ return 1;
+}
+#endif
+
+/*
+ * Save the ALPN extension in a ClientHello.
+ * pkt: the contents of the ALPN extension, not including type and length.
+ * al: a pointer to the alert value to send in the event of a failure.
+ * returns: 1 on success, 0 on error.
+ */
+int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al)
+{
+ PACKET protocol_list, save_protocol_list, protocol;
+
+ if (s->s3->tmp.finish_md_len != 0)
+ return 1;
+
+ if (!PACKET_as_length_prefixed_2(pkt, &protocol_list)
+ || PACKET_remaining(&protocol_list) < 2) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ save_protocol_list = protocol_list;
+ do {
+ /* Protocol names can't be empty. */
+ if (!PACKET_get_length_prefixed_1(&protocol_list, &protocol)
+ || PACKET_remaining(&protocol) == 0) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+ } while (PACKET_remaining(&protocol_list) != 0);
+
+ if (!PACKET_memdup(&save_protocol_list,
+ &s->s3->alpn_proposed, &s->s3->alpn_proposed_len)) {
+ *al = TLS1_AD_INTERNAL_ERROR;
+ return 0;
+ }
+
+ return 1;
+}
+
+#ifndef OPENSSL_NO_SRTP
+int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al)
+{
+ SRTP_PROTECTION_PROFILE *sprof;
+ STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
+ unsigned int ct, mki_len, id;
+ int i, srtp_pref;
+ PACKET subpkt;
+
+ /* Ignore this if we have no SRTP profiles */
+ if (SSL_get_srtp_profiles(s) == NULL)
+ return 1;
+
+ /* Pull off the length of the cipher suite list and check it is even */
+ if (!PACKET_get_net_2(pkt, &ct)
+ || (ct & 1) != 0 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
+ SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ srvr = SSL_get_srtp_profiles(s);
+ s->srtp_profile = NULL;
+ /* Search all profiles for a match initially */
+ srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
+
+ while (PACKET_remaining(&subpkt)) {
+ if (!PACKET_get_net_2(&subpkt, &id)) {
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
+ SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ /*
+ * Only look for match in profiles of higher preference than
+ * current match.
+ * If no profiles have been have been configured then this
+ * does nothing.
+ */
+ for (i = 0; i < srtp_pref; i++) {
+ sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
+ if (sprof->id == id) {
+ s->srtp_profile = sprof;
+ srtp_pref = i;
+ break;
+ }
+ }
+ }
+
+ /*
+ * Now extract the MKI value as a sanity check, but discard it for now
+ */
+ if (!PACKET_get_1(pkt, &mki_len)) {
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
+ SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ if (!PACKET_forward(pkt, mki_len)
+ || PACKET_remaining(pkt)) {
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP, SSL_R_BAD_SRTP_MKI_VALUE);
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ return 1;
+}
+#endif
+
+int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al)
+{
+ if (!(s->options & SSL_OP_NO_ENCRYPT_THEN_MAC))
+ s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
+
+ 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;
+}
+
+/*
+ * Process a key_share extension received in the ClientHello. |pkt| contains
+ * the raw PACKET data for the extension. Returns 1 on success or 0 on failure.
+ * If a failure occurs then |*al| is set to an appropriate alert value.
+ */
+int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al)
+{
+ unsigned int group_id;
+ PACKET key_share_list, encoded_pt;
+ const unsigned char *clntcurves, *srvrcurves;
+ size_t clnt_num_curves, srvr_num_curves;
+ int group_nid, found = 0;
+ unsigned int curve_flags;
+
+ if (s->hit)
+ return 1;
+
+ /* Sanity check */
+ if (s->s3->peer_tmp != NULL) {
+ *al = SSL_AD_INTERNAL_ERROR;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+
+ if (!PACKET_as_length_prefixed_2(pkt, &key_share_list)) {
+ *al = SSL_AD_HANDSHAKE_FAILURE;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_LENGTH_MISMATCH);
+ return 0;
+ }
+
+ /* Get our list of supported curves */
+ if (!tls1_get_curvelist(s, 0, &srvrcurves, &srvr_num_curves)) {
+ *al = SSL_AD_INTERNAL_ERROR;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+
+ /* Get the clients list of supported curves */
+ if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
+ *al = SSL_AD_INTERNAL_ERROR;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+
+ while (PACKET_remaining(&key_share_list) > 0) {
+ if (!PACKET_get_net_2(&key_share_list, &group_id)
+ || !PACKET_get_length_prefixed_2(&key_share_list, &encoded_pt)
+ || PACKET_remaining(&encoded_pt) == 0) {
+ *al = SSL_AD_HANDSHAKE_FAILURE;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE,
+ SSL_R_LENGTH_MISMATCH);
+ return 0;
+ }
+
+ /*
+ * If we already found a suitable key_share we loop through the
+ * rest to verify the structure, but don't process them.
+ */
+ if (found)
+ continue;
+
+ /* Check if this share is in supported_groups sent from client */
+ if (!check_in_list(s, group_id, clntcurves, clnt_num_curves, 0)) {
+ *al = SSL_AD_HANDSHAKE_FAILURE;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_KEY_SHARE);
+ return 0;
+ }
+
+ /* Check if this share is for a group we can use */
+ if (!check_in_list(s, group_id, srvrcurves, srvr_num_curves, 1)) {
+ /* Share not suitable */
+ continue;
+ }
+
+ group_nid = tls1_ec_curve_id2nid(group_id, &curve_flags);
+
+ if (group_nid == 0) {
+ *al = SSL_AD_INTERNAL_ERROR;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE,
+ SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
+ return 0;
+ }
+
+ if ((curve_flags & TLS_CURVE_TYPE) == TLS_CURVE_CUSTOM) {
+ /* Can happen for some curves, e.g. X25519 */
+ EVP_PKEY *key = EVP_PKEY_new();
+
+ if (key == NULL || !EVP_PKEY_set_type(key, group_nid)) {
+ *al = SSL_AD_INTERNAL_ERROR;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB);
+ EVP_PKEY_free(key);
+ return 0;
+ }
+ s->s3->peer_tmp = key;
+ } else {
+ /* Set up EVP_PKEY with named curve as parameters */
+ EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL);
+ if (pctx == NULL
+ || EVP_PKEY_paramgen_init(pctx) <= 0
+ || EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx,
+ group_nid) <= 0
+ || EVP_PKEY_paramgen(pctx, &s->s3->peer_tmp) <= 0) {
+ *al = SSL_AD_INTERNAL_ERROR;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB);
+ EVP_PKEY_CTX_free(pctx);
+ return 0;
+ }
+ EVP_PKEY_CTX_free(pctx);
+ pctx = NULL;
+ }
+ s->s3->group_id = group_id;
+
+ if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
+ PACKET_data(&encoded_pt),
+ PACKET_remaining(&encoded_pt))) {
+ *al = SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_ECPOINT);
+ return 0;
+ }
+
+ found = 1;
+ }
+
+ return 1;
+}
+
+#ifndef OPENSSL_NO_EC
+int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al)
+{
+ PACKET supported_groups_list;
+
+ /* Each group is 2 bytes and we must have at least 1. */
+ if (!PACKET_as_length_prefixed_2(pkt, &supported_groups_list)
+ || PACKET_remaining(&supported_groups_list) == 0
+ || (PACKET_remaining(&supported_groups_list) % 2) != 0) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ if (!s->hit
+ && !PACKET_memdup(&supported_groups_list,
+ &s->session->tlsext_supportedgroupslist,
+ &s->session->tlsext_supportedgroupslist_length)) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ return 1;
+}
+#endif
+
+int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al)
+{
+ /* The extension must always be empty */
+ if (PACKET_remaining(pkt) != 0) {
+ *al = SSL_AD_DECODE_ERROR;
+ return 0;
+ }
+
+ s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS;
+
+ return 1;
+}
