Don't do version neg on an HRR
[openssl.git] / ssl / statem / extensions.c
index 3d830a7b76f94222eace3e976a64cbf2ccd36ade..e16b75f683dcd3ee259dcca94fe5f627b1c8445c 100644 (file)
@@ -29,6 +29,7 @@ static int init_status_request(SSL *s, unsigned int context);
 static int init_npn(SSL *s, unsigned int context);
 #endif
 static int init_alpn(SSL *s, unsigned int context);
+static int final_alpn(SSL *s, unsigned int context, int sent, int *al);
 static int init_sig_algs(SSL *s, unsigned int context);
 static int init_certificate_authorities(SSL *s, unsigned int context);
 static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
@@ -203,7 +204,7 @@ static const EXTENSION_DEFINITION ext_defs[] = {
         SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
         | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
         init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
-        tls_construct_stoc_alpn, tls_construct_ctos_alpn, NULL
+        tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
     },
 #ifndef OPENSSL_NO_SRTP
     {
@@ -407,13 +408,23 @@ static int verify_extension(SSL *s, unsigned int context, unsigned int type,
  */
 int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx)
 {
+    int is_tls13;
+
+    /*
+     * For HRR we haven't selected the version yet but we know it will be
+     * TLSv1.3
+     */
+    if ((thisctx & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0)
+        is_tls13 = 1;
+    else
+        is_tls13 = SSL_IS_TLS13(s);
+
     if ((SSL_IS_DTLS(s)
                 && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
             || (s->version == SSL3_VERSION
                     && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
-            || (SSL_IS_TLS13(s)
-                && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
-            || (!SSL_IS_TLS13(s) && (extctx & SSL_EXT_TLS1_3_ONLY) != 0)
+            || (is_tls13 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
+            || (!is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0)
             || (s->hit && (extctx & SSL_EXT_IGNORE_ON_RESUMPTION) != 0))
         return 0;
 
@@ -702,11 +713,11 @@ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
     if (!WPACKET_start_sub_packet_u16(pkt)
                /*
                 * If extensions are of zero length then we don't even add the
-                * extensions length bytes to a ClientHello/ServerHello in SSLv3
+                * extensions length bytes to a ClientHello/ServerHello
+                * (for non-TLSv1.3).
                 */
             || ((context &
                  (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0
-                && s->version == SSL3_VERSION
                 && !WPACKET_set_flags(pkt,
                                      WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
         SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
@@ -823,6 +834,7 @@ static int final_server_name(SSL *s, unsigned int context, int sent,
 {
     int ret = SSL_TLSEXT_ERR_NOACK;
     int altmp = SSL_AD_UNRECOGNIZED_NAME;
+    int was_ticket = (SSL_get_options(s) & SSL_OP_NO_TICKET) == 0;
 
     if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
         ret = s->ctx->ext.servername_cb(s, &altmp,
@@ -832,6 +844,40 @@ static int final_server_name(SSL *s, unsigned int context, int sent,
         ret = s->session_ctx->ext.servername_cb(s, &altmp,
                                        s->session_ctx->ext.servername_arg);
 
+    if (!sent) {
+        OPENSSL_free(s->session->ext.hostname);
+        s->session->ext.hostname = NULL;
+    }
+
+    /*
+     * If we're expecting to send a ticket, and tickets were previously enabled,
+     * and now tickets are disabled, then turn off expected ticket.
+     * Also, if this is not a resumption, create a new session ID
+     */
+    if (ret == SSL_TLSEXT_ERR_OK && s->ext.ticket_expected
+            && was_ticket && (SSL_get_options(s) & SSL_OP_NO_TICKET) != 0) {
+        s->ext.ticket_expected = 0;
+        if (!s->hit) {
+            SSL_SESSION* ss = SSL_get_session(s);
+
+            if (ss != NULL) {
+                OPENSSL_free(ss->ext.tick);
+                ss->ext.tick = NULL;
+                ss->ext.ticklen = 0;
+                ss->ext.tick_lifetime_hint = 0;
+                ss->ext.tick_age_add = 0;
+                ss->ext.tick_identity = 0;
+                if (!ssl_generate_session_id(s, ss)) {
+                    ret = SSL_TLSEXT_ERR_ALERT_FATAL;
+                    altmp = SSL_AD_INTERNAL_ERROR;
+                }
+            } else {
+                ret = SSL_TLSEXT_ERR_ALERT_FATAL;
+                altmp = SSL_AD_INTERNAL_ERROR;
+            }
+        }
+    }
+
     switch (ret) {
     case SSL_TLSEXT_ERR_ALERT_FATAL:
         *al = altmp;
@@ -843,6 +889,8 @@ static int final_server_name(SSL *s, unsigned int context, int sent,
 
     case SSL_TLSEXT_ERR_NOACK:
         s->servername_done = 0;
+        if (s->server && s->session->ext.hostname != NULL)
+            s->ext.early_data_ok = 0;
         return 1;
 
     default:
@@ -940,6 +988,24 @@ static int init_alpn(SSL *s, unsigned int context)
     return 1;
 }
 
+static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
+{
+    if (!s->server && !sent && s->session->ext.alpn_selected != NULL)
+            s->ext.early_data_ok = 0;
+
+    if (!s->server || !SSL_IS_TLS13(s))
+        return 1;
+
+    /*
+     * Call alpn_select callback if needed.  Has to be done after SNI and
+     * cipher negotiation (HTTP/2 restricts permitted ciphers). In TLSv1.3
+     * we also have to do this before we decide whether to accept early_data.
+     * In TLSv1.3 we've already negotiated our cipher so we do this call now.
+     * For < TLSv1.3 we defer it until after cipher negotiation.
+     */
+    return tls_handle_alpn(s, al);
+}
+
 static int init_sig_algs(SSL *s, unsigned int context)
 {
     /* Clear any signature algorithms extension received */
@@ -1116,36 +1182,25 @@ static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
                 && (!s->hit
                     || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
                        != 0)) {
-            const unsigned char *pcurves, *pcurvestmp, *clntcurves;
-            size_t num_curves, clnt_num_curves, i;
+            const uint16_t *pgroups, *clntgroups;
+            size_t num_groups, clnt_num_groups, i;
             unsigned int group_id = 0;
 
             /* Check if a shared group exists */
 
             /* Get the clients list of supported groups. */
-            if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
-                *al = SSL_AD_INTERNAL_ERROR;
-                SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
-                return 0;
-            }
-
-            /* Get our list of available groups */
-            if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
-                *al = SSL_AD_INTERNAL_ERROR;
-                SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
-                return 0;
-            }
+            tls1_get_peer_groups(s, &clntgroups, &clnt_num_groups);
+            tls1_get_supported_groups(s, &pgroups, &num_groups);
 
             /* Find the first group we allow that is also in client's list */
-            for (i = 0, pcurvestmp = pcurves; i < num_curves;
-                 i++, pcurvestmp += 2) {
-                group_id = bytestogroup(pcurvestmp);
+            for (i = 0; i < num_groups; i++) {
+                group_id = pgroups[i];
 
-                if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
+                if (check_in_list(s, group_id, clntgroups, clnt_num_groups, 1))
                     break;
             }
 
-            if (i < num_curves) {
+            if (i < num_groups) {
                 /* A shared group exists so send a HelloRetryRequest */
                 s->s3->group_id = group_id;
                 s->hello_retry_request = 1;
@@ -1369,19 +1424,31 @@ int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
 
 static int final_early_data(SSL *s, unsigned int context, int sent, int *al)
 {
-    if (!s->server || !sent)
+    if (!sent)
         return 1;
 
+    if (!s->server) {
+        if (context == SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
+                && sent
+                && !s->ext.early_data_ok) {
+            /*
+             * If we get here then the server accepted our early_data but we
+             * later realised that it shouldn't have done (e.g. inconsistent
+             * ALPN)
+             */
+            *al = SSL_AD_ILLEGAL_PARAMETER;
+            return 0;
+        }
+
+        return 1;
+    }
+
     if (s->max_early_data == 0
             || !s->hit
             || s->session->ext.tick_identity != 0
             || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
             || !s->ext.early_data_ok
-            || s->hello_retry_request
-            || s->s3->alpn_selected_len != s->session->ext.alpn_selected_len
-            || (s->s3->alpn_selected_len > 0
-                && memcmp(s->s3->alpn_selected, s->session->ext.alpn_selected,
-                          s->s3->alpn_selected_len) != 0)) {
+            || s->hello_retry_request) {
         s->ext.early_data = SSL_EARLY_DATA_REJECTED;
     } else {
         s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;