+#ifndef OPENSSL_NO_EC
+/*-
+ * ssl_check_for_safari attempts to fingerprint Safari using OS X
+ * SecureTransport using the TLS extension block in |hello|.
+ * 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 CLIENTHELLO_MSG *hello)
+{
+ unsigned int type;
+ PACKET sni, tmppkt;
+ size_t ext_len;
+
+ 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 */
+ 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 */
+ };
+
+ /* Length of the common prefix (first two extensions). */
+ static const size_t kSafariCommonExtensionsLength = 18;
+
+ tmppkt = hello->extensions;
+
+ if (!PACKET_forward(&tmppkt, 2)
+ || !PACKET_get_net_2(&tmppkt, &type)
+ || !PACKET_get_length_prefixed_2(&tmppkt, &sni)) {
+ return;
+ }
+
+ if (type != TLSEXT_TYPE_server_name)
+ return;
+
+ ext_len = TLS1_get_client_version(s) >= TLS1_2_VERSION ?
+ sizeof(kSafariExtensionsBlock) : kSafariCommonExtensionsLength;
+
+ s->s3->is_probably_safari = PACKET_equal(&tmppkt, kSafariExtensionsBlock,
+ ext_len);
+}
+#endif /* !OPENSSL_NO_EC */
+