+/* Parse the server's max fragment len extension packet */
+int tls_parse_stoc_maxfragmentlen(SSL *s, PACKET *pkt, unsigned int context,
+ X509 *x, size_t chainidx)
+{
+ unsigned int value;
+
+ if (PACKET_remaining(pkt) != 1 || !PACKET_get_1(pkt, &value)) {
+ SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PARSE_STOC_MAXFRAGMENTLEN,
+ SSL_R_BAD_EXTENSION);
+ return 0;
+ }
+
+ /* |value| should contains a valid max-fragment-length code. */
+ if (!IS_MAX_FRAGMENT_LENGTH_EXT_VALID(value)) {
+ SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+ SSL_F_TLS_PARSE_STOC_MAXFRAGMENTLEN,
+ SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH);
+ return 0;
+ }
+
+ /* Must be the same value as client-configured one who was sent to server */
+ /*-
+ * RFC 6066: if a client receives a maximum fragment length negotiation
+ * response that differs from the length it requested, ...
+ * It must abort with SSL_AD_ILLEGAL_PARAMETER alert
+ */
+ if (value != s->ext.max_fragment_len_mode) {
+ SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+ SSL_F_TLS_PARSE_STOC_MAXFRAGMENTLEN,
+ SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH);
+ return 0;
+ }
+
+ /*
+ * Maximum Fragment Length Negotiation succeeded.
+ * The negotiated Maximum Fragment Length is binding now.
+ */
+ s->session->ext.max_fragment_len_mode = value;
+
+ return 1;
+}
+