+ s2n(TLSEXT_TYPE_ec_point_formats, ret);
+ s2n(s->tlsext_ecpointformatlist_length + 1, ret);
+ *(ret++) = (unsigned char)s->tlsext_ecpointformatlist_length;
+ memcpy(ret, s->tlsext_ecpointformatlist,
+ s->tlsext_ecpointformatlist_length);
+ ret += s->tlsext_ecpointformatlist_length;
+
+ }
+ /*
+ * Currently the server should not respond with a SupportedCurves
+ * extension
+ */
+# endif /* OPENSSL_NO_EC */
+
+ if (s->tlsext_ticket_expected && !(SSL_get_options(s) & SSL_OP_NO_TICKET)) {
+ if ((long)(limit - ret - 4) < 0)
+ return NULL;
+ s2n(TLSEXT_TYPE_session_ticket, ret);
+ s2n(0, ret);
+ }
+
+ if (s->tlsext_status_expected) {
+ if ((long)(limit - ret - 4) < 0)
+ return NULL;
+ s2n(TLSEXT_TYPE_status_request, ret);
+ s2n(0, ret);
+ }
+# ifdef TLSEXT_TYPE_opaque_prf_input
+ if (s->s3->server_opaque_prf_input != NULL && s->version != DTLS1_VERSION) {
+ size_t sol = s->s3->server_opaque_prf_input_len;
+
+ if ((long)(limit - ret - 6 - sol) < 0)
+ return NULL;
+ if (sol > 0xFFFD) /* can't happen */
+ return NULL;
+
+ s2n(TLSEXT_TYPE_opaque_prf_input, ret);
+ s2n(sol + 2, ret);
+ s2n(sol, ret);
+ memcpy(ret, s->s3->server_opaque_prf_input, sol);
+ ret += sol;
+ }
+# endif
+
+# ifndef OPENSSL_NO_SRTP
+ if (SSL_IS_DTLS(s) && s->srtp_profile) {
+ int el;
+
+ ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
+
+ if ((limit - ret - 4 - el) < 0)
+ return NULL;
+
+ s2n(TLSEXT_TYPE_use_srtp, ret);
+ s2n(el, ret);
+
+ if (ssl_add_serverhello_use_srtp_ext(s, ret, &el, el)) {
+ SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
+ return NULL;
+ }
+ ret += el;
+ }
+# endif
+
+ if (((s->s3->tmp.new_cipher->id & 0xFFFF) == 0x80
+ || (s->s3->tmp.new_cipher->id & 0xFFFF) == 0x81)
+ && (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG)) {
+ const unsigned char cryptopro_ext[36] = {
+ 0xfd, 0xe8, /* 65000 */
+ 0x00, 0x20, /* 32 bytes length */
+ 0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85,
+ 0x03, 0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06,
+ 0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08,
+ 0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17
+ };
+ if (limit - ret < 36)
+ return NULL;
+ memcpy(ret, cryptopro_ext, 36);
+ ret += 36;
+
+ }
+# ifndef OPENSSL_NO_HEARTBEATS
+ /* Add Heartbeat extension if we've received one */
+ if (s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) {
+ if ((limit - ret - 4 - 1) < 0)
+ return NULL;
+ s2n(TLSEXT_TYPE_heartbeat, ret);
+ s2n(1, ret);
+ /*-
+ * Set mode:
+ * 1: peer may send requests
+ * 2: peer not allowed to send requests
+ */
+ if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
+ *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
+ else
+ *(ret++) = SSL_TLSEXT_HB_ENABLED;
+
+ }
+# endif
+
+# ifndef OPENSSL_NO_NEXTPROTONEG
+ 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) {
+ const unsigned char *npa;
+ unsigned int npalen;
+ int r;
+
+ r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen,
+ s->
+ ctx->next_protos_advertised_cb_arg);
+ if (r == SSL_TLSEXT_ERR_OK) {
+ if ((long)(limit - ret - 4 - npalen) < 0)
+ return NULL;
+ s2n(TLSEXT_TYPE_next_proto_neg, ret);
+ s2n(npalen, ret);
+ memcpy(ret, npa, npalen);
+ ret += npalen;
+ s->s3->next_proto_neg_seen = 1;
+ }
+ }
+# endif
+
+ if ((extdatalen = ret - orig - 2) == 0)
+ return orig;
+
+ s2n(extdatalen, orig);
+ return ret;
+}
+
+# ifndef OPENSSL_NO_EC
+/*-
+ * ssl_check_for_safari attempts to fingerprint Safari using OS X
+ * SecureTransport using the TLS extension block in |d|, of length |n|.
+ * Safari, since 10.6, sends exactly these extensions, in this order:
+ * SNI,
+ * elliptic_curves
+ * ec_point_formats
+ *
+ * We wish to fingerprint Safari because they broke ECDHE-ECDSA support in 10.8,
+ * but they advertise support. So enabling ECDHE-ECDSA ciphers breaks them.
+ * Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
+ * 10.8..10.8.3 (which don't work).
+ */
+static void ssl_check_for_safari(SSL *s, const unsigned char *data,
+ const unsigned char *d, int n)
+{
+ unsigned short type, size;
+ static const unsigned char kSafariExtensionsBlock[] = {
+ 0x00, 0x0a, /* elliptic_curves extension */
+ 0x00, 0x08, /* 8 bytes */
+ 0x00, 0x06, /* 6 bytes of curve ids */
+ 0x00, 0x17, /* P-256 */
+ 0x00, 0x18, /* P-384 */
+ 0x00, 0x19, /* P-521 */
+
+ 0x00, 0x0b, /* ec_point_formats */
+ 0x00, 0x02, /* 2 bytes */
+ 0x01, /* 1 point format */
+ 0x00, /* uncompressed */
+ };
+
+ /* The following is only present in TLS 1.2 */
+ static const unsigned char kSafariTLS12ExtensionsBlock[] = {
+ 0x00, 0x0d, /* signature_algorithms */
+ 0x00, 0x0c, /* 12 bytes */
+ 0x00, 0x0a, /* 10 bytes */
+ 0x05, 0x01, /* SHA-384/RSA */
+ 0x04, 0x01, /* SHA-256/RSA */
+ 0x02, 0x01, /* SHA-1/RSA */
+ 0x04, 0x03, /* SHA-256/ECDSA */
+ 0x02, 0x03, /* SHA-1/ECDSA */
+ };
+
+ if (data >= (d + n - 2))
+ return;
+ data += 2;
+
+ if (data > (d + n - 4))
+ return;
+ n2s(data, type);
+ n2s(data, size);
+
+ if (type != TLSEXT_TYPE_server_name)
+ return;
+
+ if (data + size > d + n)
+ return;
+ data += size;
+
+ if (TLS1_get_client_version(s) >= TLS1_2_VERSION) {
+ const size_t len1 = sizeof(kSafariExtensionsBlock);
+ const size_t len2 = sizeof(kSafariTLS12ExtensionsBlock);
+
+ if (data + len1 + len2 != d + n)
+ return;
+ if (memcmp(data, kSafariExtensionsBlock, len1) != 0)
+ return;
+ if (memcmp(data + len1, kSafariTLS12ExtensionsBlock, len2) != 0)
+ return;
+ } else {
+ const size_t len = sizeof(kSafariExtensionsBlock);
+
+ if (data + len != d + n)
+ return;
+ if (memcmp(data, kSafariExtensionsBlock, len) != 0)
+ return;
+ }
+
+ s->s3->is_probably_safari = 1;
+}
+# endif /* !OPENSSL_NO_EC */
+
+int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
+ int n, int *al)
+{
+ unsigned short type;
+ unsigned short size;
+ unsigned short len;
+ unsigned char *data = *p;
+ int renegotiate_seen = 0;
+ int sigalg_seen = 0;
+
+ s->servername_done = 0;
+ s->tlsext_status_type = -1;
+# ifndef OPENSSL_NO_NEXTPROTONEG
+ s->s3->next_proto_neg_seen = 0;
+# endif
+
+# ifndef OPENSSL_NO_HEARTBEATS
+ s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
+ SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
+# endif
+
+# ifndef OPENSSL_NO_EC
+ if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
+ ssl_check_for_safari(s, data, d, n);
+# endif /* !OPENSSL_NO_EC */
+
+# ifndef OPENSSL_NO_SRP
+ if (s->srp_ctx.login != NULL) {
+ OPENSSL_free(s->srp_ctx.login);
+ s->srp_ctx.login = NULL;
+ }
+# endif
+
+ s->srtp_profile = NULL;
+
+ if (data >= (d + n - 2))
+ goto ri_check;
+ n2s(data, len);
+
+ if (data > (d + n - len))
+ goto ri_check;
+
+ while (data <= (d + n - 4)) {
+ n2s(data, type);
+ n2s(data, size);
+
+ if (data + size > (d + n))
+ goto ri_check;
+# if 0
+ fprintf(stderr, "Received extension type %d size %d\n", type, size);
+# endif
+ if (s->tlsext_debug_cb)
+ s->tlsext_debug_cb(s, 0, type, data, size, s->tlsext_debug_arg);
+/*-
+ * 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.
+ *
+ */